La stéatose hépatique non alcoolique, regroupant la stéatose isolée (NAFLD) et la stéatohépatite non-alcoolique (NASH), est un enjeu de santé publique mondial en raison d’une incidence croissante, en grande partie expliquée par l’augmentation de la prévalence du diabète et de l’obésité. La stéatose hépatique prédit la survenue des complications métaboliques associées à l’insulinorésistance, comme le diabète ou les événements cardiovasculaires. La connaissance de l’histoire naturelle de la NAFLD comporte encore de nombreuses incertitudes. Actuellement le modèle explicatif repose sur une dichotomie entre la stéatohépatite (NASH), qui peut progresser vers la cirrhose et la stéatose isolée ou avec inflammation minime (NAFL) qui jusqu'à présent était considérée comme une condition non évolutive ne progressant pas vers la cirrhose et n'augmentant pas la morbi-mortalité d'origine hépatique. Cette dichotomie conditionne en grande partie la prise en charge de ces patients, ceux avec NAFL étant souvent rassurés par le praticien quant à leur devenir et ne bénéficiant pas d'une surveillance hépatique spécifique. La ponction biopsie du foie est considérée comme un examen de référence, mais son usage en pratique clinique reste limité en raison d’effets indésirables, d’erreurs d'échantillonnage et de la variabilité d’interprétation inter-observateur. Les méthodes non invasives de lésions hépatiques sont devenues une vraie alternative à la biopsie du foie pour la prise en charge des patients ayant une maladie chronique du foie, au cours des dix dernières années. / Non-alcoholic fatty liver disease (NAFLD) covers a spectrum ranging from isolated steatosis to non-alcoholic steatohepatitis (NASH) and is becoming one of the most frequent causes of chronic liver disease, mainly because of its close association with the worldwide epidemic of diabetes and obesity. Liver steatosis can predict the occurrence of metabolic complications associated with insulin resistance, such as diabetes and cardiovascular events. Our understanding of the natural history of NAFLD is still incomplete. Currently, the explicative model is based on a dichotomy between steatohepatitis, considered the progressive form of the disease, which can lead to cirrhosis and isolated steatosis with or without minimal inflammation, which is considered a non-progressive condition that does not impact overall survival or result in liver-related mortality and morbidity. This dichotomy largely determines the management of NAFLD patients: patients without steatohepatitis usually do not undergo specific monitoring for liver disease progression. Liver biopsy is considered the reference diagnostic method but its implementation in clinical practice remains limited due to procedure complexity, invasiveness, cost, potential complications, sampling error and inter-observer variability. Non-invasive methods of hepatic injury have become a real alternative to liver biopsy for the diagnosis of patients with chronic liver disease in the past decade. The aims of this thesis were: 1) to better understand the histological course of the disease, to better identify patients at risk of histological progression based on initial histological findings and to establish a correlation between histological changes and the course of metabolic co-morbidities often associated with NAFLD : 2) to establish factors associated with short-term variability of repeated measurements of elastometry in patients with chronic liver diseases in order to understand how this non invasive procedure can be used for patient monitoring 3) to determine the diagnostic value and limitations of several steatosis biomarkers using liver biopsy as a reference standard in a large cohort of patients with suspected NAFLD. Our study shows that a fraction of patients with isolated steatosis can unambiguously evolve towards well-defined steatohepatitis, and in some of them, bridging fibrosis. The presence of mild lobular inflammation or any amount of fibrosis substantially increases the risk of histological progression in the mid-term while those with steatosis alone are at lowest risk. Patients with disease progression experienced a deterioration of cardio-metabolic risk factors. Our data if validated by independent studies, allow for better stratification of patients at risk of disease progression. The results of this study favor a change in the practices of monitoring and risk assessment of patients with steatosis but without steatohepatitis.

Patients with type 2 diabetes (T2D) are at risk for non-alcoholic fatty liver disease (NAFLD) and associated complications. This study evaluated the performance of international (EASL-EASD-EASO) and national (DGVS) guidelines for NAFLD risk stratification. Patients with T2D prospectively underwent ultrasound, liver stiffness measurement (LSM) and serum-based fibrosis markers. Guideline-based risk classification and referral rates for different screening approaches were compared and the diagnostic properties of simplified algorithms, genetic markers and a new NASH surrogate (FAST score) were evaluated. NAFLD risk was present in 184 of 204 screened patients (age 64.2 ± 10.7 years; BMI 32.6 ± 7.6 kg/m2). EASL-EASD-EASO recommended specialist referral for 60–77% depending on the fibrosis score used, only 6% were classified as low risk. The DGVS algorithm required LSM for 76%; 25% were referred for specialised care. The sensitivities of the diagnostic pathways were 47–96%. A simplified referral strategy revealed a sensitivity/specificity of 46/88% for fibrosis risk. Application of the FAST score reduced the referral rate to 35%. This study (a) underlines the high prevalence of fibrosis risk in T2D, (b) demonstrates very high referral rates for in-depth hepatological work-up, and (c) indicates that simpler referral algorithms may produce comparably good results and could facilitate NAFLD screening.

No description available.

Thesis (MScMedSc)--Stellenbosch University, 2011. / ENGLISH ABSTRACT: Non-Alcoholic Fatty Liver Disease (NAFLD) is the most prevalent chronic liver disease in Western countries and is considered the hepatic manifestation of the Metabolic Syndrome (MetS). Its heterogeneous nature ranges from hepatic steatosis through steatohepatitis to advanced fibrosis and cirrhosis where the ingestion of significant amounts of alcohol has been excluded. The disease profile of NAFLD and its necro-inflammatory subset Nonalcoholic Steatohepatitis (NASH) were described in the parent study, which provided a clinically well-characterised patient cohort for the present investigation. South African patients with NASH had significantly higher mean serum cholesterol and triglyceride levels than those with fatty liver only. The objective of this study was to implement a high-throughput real-time polymerase chain reaction (PCR) method in our laboratory to enable the assessment of cardiovascular genetic risk factors in NAFLD patients. The specific aims were to determine the clinical utility and perform analytical validation of each mutation included in the multi-gene cardiovascular disease (CVD) screening assay. The Pathology Supported Genetic Testing (PSGT) concept developed at our department provides a practical approach to personalized medicine. The CVD multi-gene screen analyses key metabolic pathways relating to atherogenic dyslipidaemia, chronic inflammation, hypercoagulation and iron dysregulation implicated in insulin resistance, which is known to be a universal factor in the pathogenesis of NAFLD. Deleterious low-penetrance mutations in the APOE (APOE2 and E4 alleles), MTHFR (677C>T and 1298A>C), F2 (20210G>A), FV (1691G>A, Leiden) and HFE (C282Y and H63D) genes were included for analysis due to their important role as genetic contributors to these biological processes. A total of 178 patients diagnosed with NAFLD and 75 controls were studied using direct DNA sequencing and a RT-PCR system for mutation detection. In addition, two patients with high ferritin levels were included as case studies. A significant association was found between HFE mutations and elevated Alanine Transaminase (ALT) levels in the NAFLD population (p = 0.04). This discovery is interpreted as the identification of a subset of patients at greater risk of developing progressive liver damage who would benefit most from genetic testing to direct more aggressive therapy at an earlier stage. The necessity of an integrative, systems-based network approach was demonstrated to more accurately distinguish between Hereditary Haemochromatosis (HH) and Insulin Resistance-associated Hepatic Iron Overload (IR-HIO) syndrome in obese patients. The PSGT approach to personalized medicine facilitates diagnosis of CVD subtypes, prevention of cumulative risk and the formulation of gene-based intervention programs tailored to the needs of the patient. These findings support the clinical utility of the CVD multi-gene test to guide chronic disease risk management in patients with NAFLD. The HFE mutation detection component of this test is of particular relevance in directing an effective treatment strategy in patients with a medical history of CVD and/or high iron stores. / AFRIKAANSE OPSOMMING: Nie-Alkoholiese Vettige Lewer Siekte (NAFLD) is die mees algemene kroniese lewer siekte in Westerse lande en word bestempel as die hepatiese manifestasie van die Metaboliese Sindroom (MetS). Die heterogene natuur van NAFLD strek van hepatiese steatose deur steatohepatietis tot gevorderde fibrose en sirrose waar grootskaalse alkohol inname uitgesluit is. Die siekte-profiel van NAFLD en sy nekro-inflammatoriese subtipe Nie-Alkoholiese Steatohepatietis (NASH) is reeds beskryf in die ouer studie, wat ‗n klinies goed-gekarakteriseerde pasiënt groep vir die huidige ondersoek daar gestel het. Suid-Afrikaanse pasiënte met NASH het beduidend hoër gemiddelde serum cholesterol en trigliseried vlakke in vergelyking met slegs vettige lewer. Die doel van hierdie studie was om ‗n hoë deurvoer rieëltyd polimerase kettingreaksie (RT-PCR) metode in ons laboratorium te implimenteer om kardiovaskulêre genetiese risiko faktore in NAFLD pasiënte te ondersoek. Die spesifieke mikpunte was om die kliniese nut en analitiese geldigheid van elke mutasie wat ingesluit is in die multi-geen kardiovaskulêre siekte (KVS) siftings toets vas te stel. Die Patologie Ondersteunde Genetiese Toetsing (PSGT) konsep wat by ons departement ontwikkel is, verskaf ‗n praktiese benadering tot persoonlike medisyne. Die KVS multi-geen toets analiseer belangrike metaboliese weë verwant aan atherogene dyslipidemie, kroniese inflammasie, oormatige bloedstolling en yster disregulering wat betrokke is by insulien weerstand wat bekend is as ‗n universele factor in the patogenese van NAFLD. Nadelige lae-penetrasie mutasies in die APOE (APOE2 en E4 allele), MTHFR (677C>T en 1298A>C) F2 (20210G>A), FV (1691G>A, Leiden) en HFE (C282Y en H63D) gene was ingesluit vir analise as gevolg van hul belangrike rol as genetiese bydraers tot die bogenoemde biologiese prosesse. ‗n Totaal van 178 pasiënte gediagnoseer met NAFLD en 75 kontroles is bestudeer deur gebruik te maak van direkte DNA volgordebepaling en ‗n RT-PCR metode vir mutasie opsporing. Twee pasiënte met verhoogde ferritien vlakke is ook as gevalle studies ingesluit. ‗n Beduidende assosiasie is gevind tussen HFE mutasies en verhoogde Alanien Transaminase (ALT) vlakke in die NAFLD studiepopulasie (p = 0.04) wat aanduidend is van ‗n subgroup van pasiënte wat die meeste baat sal vind uit genetiese toetsing om meer aggressiewe behandeling te rig op' n vroeër stadium. Die noodsaaklikheid van 'n geïntegreerde, stelsels-gebaseerde netwerk benadering is gewys om meer akkuraat te onderskei tussen Oorerflike Hemochromatose (HH) en Insulien Weerstand-geassosieerde Hepatiese Yster Oorlading (IR-HIO) sindroom in vetsugtige pasiënte. Die PSGT benadering tot persoonlike medisyne formuleer geen-gebaseerde intervensie programme aangepas tot die behoeftes van die pasiënt ek maak diagnose van KVS-subtipes en voorkoming van kumulatiewe risiko moontlik. Hierdie bevindinge ondersteun die kliniese nut van die KVS multi-geen toets om riglyne vir die risikobestuur van kroniese siektes soos NAFLD daar te stel. Die HFE mutasie opsporings komponent van hierdie toets is van besondere belang om 'n effektiewe strategie vir die behandeling van pasiënte met 'n mediese geskiedenis van KVS en/of hoë yster vlakke daar te stel.

Introdução: A obesidade é uma doença crônica que aumenta sua prevalência progressivamente no mundo todo. Uma das suas principais complicações é a doença hepática gordurosa não alcoólica (DHGNA), que pode apresentar-se de forma assintomática, com esteatose hepática, esteato-hepatite, cirrose e hepatocarcinoma. Está associada à dislipidemia, hipertensão, diabetes, síndrome metabólica e resistência insulínica. O padrão ouro para seu diagnóstico é a biopsia hepática, considerado método invasivo. Medidas indiretas são usadas para auxiliar na sua detecção, como dados do exame físico, exames de bioquímica e de imagem. Objetivo: Diagnosticar DHGNA usando a ressonância nuclear magnética (RNM) como método não invasivo, correlacionando-a com achados clínicos e laboratoriais. Metodologia: Estudo transversal de 50 crianças e adolescentes seguidas no Ambulatório de Obesidade do Hospital das Clínicas da FMRP-USP. Foram submetidas à questionário sobre histórico pessoal e familiar, à exame físico, exames laboratoriais (lipidograma, transaminases, glicemia e insulina basal) e RNM de abdome para cálculo da de gordura hepática, visceral e subcutânea. Resultados: Diagnosticado esteatose hepática em 14 (28%) dos participantes, sendo 8 com esteatose grave (porcentagem de gordura >18%) e 4 não grave (porcentagem gordura hepática entre 9 e 18%). Houve diferença estatisticamente significante entre a gordura hepática detectada pela RNM e o gênero masculino, triglicérides, TGO, TGP, relação TGO/TGP e acantose nigricans. O cálculo do Homeostasis Model Assessment Insulin Resistance (HOMA-IR) e da síndrome metabólica não apresentaram relação positiva com a porcentagem de gordura hepática. Conclusão: A frequência de esteatose hepática, utilizando a RNM como ferramenta diagnóstica, foi inferior à encontrada na literatura. Dos parâmetros estudados, os melhores preditores de esteatose hepática foram triglicérides, TGO, TGP, relação TGO/TGP, gênero masculino, acantose nigricans e Z escore para IMC elevado / Introduction: Obesity is a chronic disease whose prevalence progressively increasing worldwide. One of its main complications is non-alcoholic fatty liver disease (NAFLD), which may occur in an asymptomatic form, as simple fatty liver, steatohepatites (NASH), cirrhosis and hepatocellular carcinoma. This disease is associated with dyslipidemia, hypertension, diabetes, metabolic syndrome and insulin resistance. The gold standard for diagnosis is a liver biopsy, considered to be an invasive method. Indirect measures are used to aid its diagnosis, such as physical, biochemical and imaging tests. Objective: Diagnosing NAFLD using MRI as non-invasive method and correlating it with clinical and laboratory findings. Methodology: A cross-sectional study of 50 children and adolescents followed at the Obesity clinic of the University Hospital, FMRP-USP. A questionnaire about personal and family history was aplplied and each subject was submitted to physical examination, laboratory tests (lipip profile, transaminases, glycemia and basal insulin) and magnetic resonance imaging (MRI) of the abdomen for calculation of hepatic, visceral and subcutaneous fat. Results: Fatty liver disease was diagnosed in 14 (28%) of the participants, 8 of them with severe steatosis (fat percentage > 18%) and 4 with milder steatosis (fat percentage between 9 and 18%). There was a statistically significant difference between the hepatic fat detected by MRI and male gender, triglycerides, AST, ALT, AST/ALT ratio and acanthosis nigricans. The calculation of the Homeostasis Model Assessment Insulin Resistance (HOMA-IR) and of the metabolic syndrome did not show a positive relationship with the percentage of hepatic fat. Conclusion: The frequency of hepatic steatosis using MRI as a diagnostic tool, was lower than the values reported in the literature. Among the parameters studied, the best predictors of liver steatosis were triglycerides, AST, ALT, AST/ALT ratio, male gender, acanthosis nigricans and Z score for high body mass index

A doença hepática gordurosa não alcoólica (DHGNA) consiste na alteração morfofisiológica do fígado decorrente do acúmulo de lipídios nos hepatócitos. O desenvolvimento de DHGNA pode estar associado à obesidade e o diabetes tipo 2, e um dos possíveis mecanismos mediadores é a hiperatividade da alça ECA/Ang II/AT1 do sistema renina angiotensina (SRA). Por outro lado, evidências mais recentes mostraram que a ativação da alça ECA2/Ang 1-7/Mas do SRA age na direção oposta, podendo atenuar as manifestações clínicas das doenças metabólicas. O treinamento físico aeróbio (TFA) tem sido amplamente recomendado para a prevenção e o tratamento de doenças metabólicas, inclusive da DHGNA, e parte das respostas benéficas podem estar associadas com a melhora do metabolismo oxidativo. Assim, o objetivo desse estudo foi investigar se a prevenção da DHGNA por meio do TFA é mediada pela melhora do metabolismo hepático associada à ativação da alça do SRA ECA2/ Ang1-7/ Mas. Para isso, camundongos C57BL/6 foram separados em grupos (n=10/grupo) sedentários (SED) alimentados com dieta normocalórica (NO) ou de cafeteria (CAF) (SED-NO e SED-CAF, respectivamente) e submetidos ao TFA alimentados com dieta NO ou CAF (TF-NO e TF-CAF, respectivamente). O grupo SED-CAF apresentou maior ganho de peso corporal, conteúdo de lipídios e de IL-6 no fígado, e o TFA previniu esses aumentos no grupo TF-CAF. Não houve diferença na concentração sérica das enzimas ALT e AST, na expressão de genes relacionados com o metabolismo lipídico e na expressão das proteínas AMPK, PGC1- , SIRT-1, ACC e receptor Mas no fígado. Os grupos TF-NO e TF-CAF apresentaram maior atividade da ECA2 no soro comparados ao SED-NO e SED-CAF, porém a atividade da ECA2 e o conteúdo do peptídio Ang1-7 não foram diferentes entre os grupos. O TF-NO apresentou menor atividade da enzima ECA no fígado comparado ao grupo TF-CAF. Coletivamente, os dados obtidos permitem afirmar que o TFA preveniu a DHGNA evidenciado pelo menor conteúdo de lipídios e citocina pró-inflamatória IL-6, no entanto, essa resposta foi independente de mudanças na expressão de genes e de proteínas reguladoras do metabolismo hepático associada à alça do SRA ECA2/ Ang1-7/ Mas / Non-alcoholic fatty liver disease (NAFLD) consists in the morphophysiological alteration of the liver due to the accumulation of lipids in the hepatocytes. The development of NAFLD may be associated with obesity and type 2 diabetes, and one of the possible mediating mechanisms is the hyperactivity of the ACE/Ang II/AT1 axis of the renin angiotensin system (RAS). On the other hand, evidence have shown that the activation of the ACE2/Ang 1-7/Mas have opposite effect, being able to attenuate clinical manifestations of the metabolic diseases. Aerobic physical training (APT) has been widely recommended for the prevention and treatment of metabolic diseases, including NAFLD, and some of the beneficial responses may be associated with improved oxidative metabolism. Thus, the aim of this study was to investigate whether the prevention of NAFLD by APT is mediated by the improvement of the metabolism associated with the activation of the RAS ACE2/Ang1-7/Mas axis. For this, C57BL/6 mice were separated into sedentary groups (SED) fed normocaloric (NO) or cafeteria (CAF) diet (SED-NO and SED-CAF, respectively) and trained with APT fed NO or CAF diet (TF-NO and TF-CAF, respectively). The SED-CAF group presented higher body weight gain, lipid and IL-6 content in the liver, and APT prevented these increases in the TF-CAF group. No differences were observed in the concentration of ALT and AST enzymes, in the expression of genes related to lipid metabolism and in the expression of AMPK, PGC1- , SIRT-1, ACC and receptor Mas in the liver. TF-NO and TF-CAF groups had higher serum ACE2 activity compared to SED-NO and SED-CAF, however ACE2 activity and Ang1-7 content were not different among groups. TF-NO showed lower ACE activity in the liver compared to the TF-CAF group. Collectively, the results showed that APT prevented NAFLD evidenced by the lower lipid content and pro-inflammatory cytokine IL-6, however, this response is independent of changes in gene expression and in hepatic metabolism regulatory proteins expression associated with the SRA ACE2/Ang1-7/Mas axis

Introdução: A hiperferritinemia (HF) pode refletir o estado inflamatório do paciente com doença hepática gordurosa não alcoólica (DHGNA) e obesidade, porém em cerca de 33% reflete uma real sobrecarga de ferro hepática. A síndrome dismetabólica relacionada ao depósito de ferro (SDDF) é caracterizada por HF, saturação de transferrina normal, alterações metabólicas e um discreto depósito de ferro hepático. O método padrão ouro para o diagnóstico de sobrecarga de ferro é a biópsia hepática. Por se tratar de método invasivo, novos métodos se tornam necessários. Dentre eles a ressonância nuclear magnética (RM) é o mais disponível. Pacientes e Métodos: O presente estudo avaliou pacientes com HF, excesso de peso, e DHGNA comprovada por biópsia hepática. Os pacientes realizaram RM pela técnica de relaxometria (análise de gordura/ferro - máquina 3T), dosagem de marcadores inflamatórios (IL-6 e TNF-alfa), análise da expressão das subunidades da ferritina (FP - cadeia pesada e FL - cadeia leve) e dosagem de hepcidina. Os dados foram comparados com a biópsia hepática. Estes pacientes foram classificados segundo os níveis de ferritina e siderose. Foram classificados em ferritina normal (FN), hiperferritinemia dismetabólica (HFD) e SDDF. O grupo de FN foi caracterizado por ferritina < 200 ng/mL em mulheres e 300 ng/mL em homens, já os pacientes do grupo HFD têm níveis elevados de ferritina e ausência de siderose hepática. Os pacientes também foram avaliados considerando somente a siderose hepática. Resultados: Foram avaliados 152 pacientes com DHGNA comprovada pela biópsia hepática, sendo 67 incluídos no estudo. A frequência de SDDF e HFD foi de 37% e 16%, respectivamente. O nível de corte da ferritina sérica, a fim de identificar depósito de ferro, foi de 180.4 ng/mL para mulheres (sensibilidade de 76,9%, especificidade de 64,3%) e 350,7 ng/mL para homens (sensibilidade de 72,7% e especificidade de 75,5%). Os pacientes com SDDF E HFD não apresentaram piores características metabólicas e histológicas. Os níveis de hepcidina foram maiores nos grupos SDDF E HFD, se correlacionando com o conteúdo de ferro hepático quando > 30,2 ng/mL. Os marcadores inflamatórios (IL-6 e TNF-alfa) foram semelhantes entre os grupos. A expressão de FP e FL se comportaram de modo semelhante entre os grupos. A FL se correlacionou com síndrome metabólica e circunferência abdominal, enquanto a FP se correlaciona com níveis maiores de esteatose. A RM foi capaz de identificar o conteúdo de ferro destes pacientes, sendo o ponto de corte de R2* 58,9s-1. A porcentagem de gordura, identificada pela RM, foi de 17% nos grupos HFD e SDDF e de 13% no grupo FN. Conclusão: 1) RM utilizando a técnica de relaxometria com correção da interferência de gordura se mostrou acurado na avaliação de discreto depósito de ferro em pacientes com SDDF; 2) HF pode refletir depósito de ferro hepático quando acima de 180,4 ng/mL para mulheres e 350,7 ng/mL para homens, não foi encontrada relação entre HF e características piores metabólicas ou histológicas; 3) FL se correlacionou com síndrome metabólica e circunferência abdominal, enquanto a FP se correlaciona com esteatose; 4) Hepcidina se correlacionou com siderose e ferritina sérica nos pacientes com DHGNA / Introduction: Hyperferritinemia (HF) may reflect the inflammatory status of patients with NAFLD and obesity, but about 33 % reflects a real hepatic iron overload. The dysmetabolic iron overload syndrome (DIOS) definition is HF, normal transferrin saturation, and mild hepatic iron overload in a patient with metabolic disorders. The gold standard for diagnosis of iron overload is the liver biopsy. As it is an invasive method, new methods are necessary. Among them, magnetic resonance imaging (MRI) is the most available one. Patients and Methods: This study evaluated patients with HF, overweight and NAFLD. All patients were submitted to liver biopsy. MRI relaxometry (fat/iron analysis - 3T machine), measurement of inflammatory markers (TNF-alpha and IL-6), analysis of the expression of ferritin light and heavy chain subunits (FL and FP) and serum hepcidin were held. Data were correlated with liver biopsy. The patients were classified considering the ferritin levels and siderosis. They were classified in three groups: normal ferritin (NF), dysmetabolic hyperferrinemia (DHF) and DIOS. The NF group has serum ferritin (SF) below 200 ng/dL for women and 300 ng/dL for men, DHF must have SF above those values and negative siderosis, and DIOS have hyperferritinemia and positive siderosis. They are also classified considering only the iron status Results: 152 biopsy-proven NAFLD patients were screened but only 67 were included in this study. DIOS and HFD frequency in our sample were 37% and 16%, respectively. The cut-off of ferritin levels were correlated with iron overload in liver biopsy was 180.4 ng/mL for women (sensibility of 76.9% and specificity of 64.3%) and 350 ng/mL for men (sensibility of 72.7% and specificity of 75.5%). Although, DHF and DIOS patients did not have worst metabolic or histological characteristics, hepcidin levels were higher in DHF and DIOS groups, correlating with hepatic siderosis when hepcidin is above 30,2 ng/mL. The inflammatory markers (IL- 6 and TNF-alpha) were similar among the groups. The expression of FP and FL were similar in role sample. FL correlates with metabolic syndrome and abdominal circumference, while FP correlates with in higher fat scores. The MRI was able to identify mild iron overload. The R2* cut off level was 58,9 s -1. The fat percentage in DIOS and HFD was of 17% each and in NF 13%. Conclusion: 1) MRI using relaxometry method is accurate to evaluate mild iron overload in DIOS patients; 2) HF may reflect iron overload when above 180.4 ng/mL for women and 350.7 ng/mL for men, however, this study didn´t find correlation between HF and insulin resistance and worst NAFLD histological characteristics; 3) FL correlates with metabolic syndrome and abdominal circumference while FP correlates with in higher fat scores 4) Hepcidin correlates with iron and serum ferritin in NAFLD patients

Introdução e Objetivos: A Doença hepática gordurosa não alcóolica (DHGNA) é claramente marcada por influência ambiental, no entanto, fatores genéticos têm sido associados a progressão para formas mais graves de DHGNA. O estresse oxidativo tem sido cada vez mais enfatizado nesta evolução e o sistema NADPH parece ser uma importante fonte de produção de espécies reativas de oxigênio. O papel dos polimorfismos do sistema NADPH nessa população e sua possível relação com progressão de doença e síndrome metabólica são desconhecidos. Desta maneira, investigamos dois polimorfismos de nucleotídeo único (SNPs) na região reguladora dos genes que codificam a NADPH oxidase 4 subunidade catalítica (NOX4) e sua subunidade regulatória p22phox (CYBA) e sua relação com variáveis histológicas e bioquímicas em pacientes com DHGNA. Métodos: 207 pacientes com DHGNA com biópsia hepática (esteatose=27; esteato-hepatite=180), sendo (70% do sexo feminino), foram genotipados para SNPs da Nox4 (rs3017887) e CYBA -675 T/A. O DNA genômico foi extraído a partir de células do sangue periférico e a genotipagem foi realizada utilizando primers específicos e sondas fluorescentes marcadas por sequenciamento. A análise histológica foi baseada na classificação de Kleiner et al (2005). Todos os pacientes eram negativos para os marcadores de hepatites virais, doença de Wilson, hemocromatose, doenças auto-imunes e tinham ingestão diária de álcool < 100 g/semana. Resultados:Associação do CYBA -675 T/A com triglicerídeos foi observada: 176,87 ± 12,93 (TT) versus 228,70 ± 21,66 (XA), p = 0,007 . Quando a população é estratificada, a associação aparece apenas entre os pacientes que possuem esteatohepatite não alcoólica (EHNA). Foi observada uma associação do CYBA-675 T / A com HDL: 48,05 ± 1,71 (TT) vs 41,70 ± 2,91 (TA) vs 28,03 ± 9,47 mg / dL (AA), p = 0,001. Quando a população é estratificada, a associação aparece apenas entre os pacientes que possuem EHNA. Quando se estudou o SNP no gene da NOX4, observou-se associação com ALT (CA + AA: 60,10 ± 6,01 U/L vs CC: 44,23 ± 4,36 U/L; P = 0,02). Porém, quando a população foi estratificada em esteatose e EHNA não se verificou diferença estatisticamente significante na frequência dos genótipos. Não houve associação de SNPs de genes que codificam proteínas do sistema NADPH oxidase nos genes CYBA (não registrado) e Nox4 (rs 3017887) e a presença de EHNA, nos portadores de DHGNA. Quanto aos resultados clínicos, observou-se que os graus de fibrose mais avançados ocorreram em pacientes com diagnóstico de Diabetes Mellitus tipo 2 (66,9% vs 37,5%; p= 0,007), além de serem mais obesos (32,2% vs 29%; p=0,003). Além disso, os níveis séricos de glicose e insulina aumentaram significantemente, de acordo com a presença de EHNA. A frequência da SM foi significativamente maior em pacientes com EHNA. Conclusões: 1) Houve associação entre a presença do genótipo CC na Nox4 SNP com uma maior concentração de ALT na população em geral 2) Houve associação entre a presença do genótipo AA no polimorfismo do gene -675 T/A CYBA com uma maior concentração de TGL e menor de HDL, nos pacientes com EHNA 3) Houve associação entre a presença de síndrome metabólica e graus avançados de fibrose hepática em portadores de DHGNA. No entanto, a amostra deve ser ampliada para confirmar estas associações, bem como, para melhor explorar possíveis relações com escores de fibrose e inflamação / Background/Aims: Oxidative stress has been implicated in progression to severe forms of non-alcoholic fatty liver disease (NAFLD). NADPH oxidase appears to be an important source of production of reactive oxygen species. We investigated by the first time two single nucleotide polymorphisms (SNPs) in the regulatory region of genes encoding the NADPH oxidase 4 (NOX4) and p22phox (CYBA) in NAFLD. Methods: 207 biopsy-proven NAFLD patients (27 = steatosis; 180= NASH) were evaluated. Genomic DNA was extracted from peripheral blood cells and on Nox4 and CYBA polymorphisms were determined by direct sequencing of PCR. All the patients were negative for markers of viral hepatitis, Metabolic diseases, autoimmune diseases and had daily intake of alcohol < 100 g/week. Results: An association of CYBA -675 T / A with triglycerides was observed: 176.87 ± 12.93 (TT) versus 228.70 ± 21.66 (XA), mean ± SEM, p = 0.007. When the population is stratified, the association appears only among patients who have non-alcoholic steatohepatitis (NASH). An association of CYBA-675 T/A with HDL was observed: 48.05 ± 1.71 (TT) vs 41.70 ± 2.91 (TA) vs 28.03 ± 9.47 mg/dL (AA), mean ± SEM, p = 0.001. When the population is stratified, the association appears only among patients who have NASH. When the NOX4 (rs 3017887) gene was studied, there was association with ALT (CA + AA: 60.10 ± 6.01 U / L vs CC: 44.23 ± 4.36 U/L; P = 0, 02). However, when the population was stratified in steatosis and NASH, there was no statistically significant difference in the frequency of genotypes. There was no association of SNPs from genes encoding NADPH oxidase system proteins in the CYBA (unregistered) and Nox4 (rs 3017887) genes and the presence of NASH in the DHGNA carriers. Regarding the clinical results, it was observed that the most advanced degrees of fibrosis occurred in patients diagnosed with Type 2 Diabetes Mellitus (66.9% vs 37.5%, p = 0.007), in addition to being more obese (32.2% % vs 29%, p = 0.003). In addition, serum glucose and insulin levels increased significantly, according to the presence of NASH. The frequency of MS was significantly higher in patients with NASH. Conclusions: 1) There was an association between the presence of the CC genotype in the Nox4 SNP with a higher concentration of ALT in the general population. 2) There was an association between the presence of the AA genotype in the CYBA gene -675 T / A polymorphism with a higher concentration of TGL and lower HDL in patients with NASH. 3) There was an association between the presence of metabolic syndrome and advanced degrees of hepatic fibrosis in patients with NAFLD. However, the sample should be expanded to confirm these associations, as well as to better explore possible relationships with fibrosis and inflammation scores

Introdução: A hiperferritinemia (HF) pode refletir o estado inflamatório do paciente com doença hepática gordurosa não alcoólica (DHGNA) e obesidade, porém em cerca de 33% reflete uma real sobrecarga de ferro hepática. A síndrome dismetabólica relacionada ao depósito de ferro (SDDF) é caracterizada por HF, saturação de transferrina normal, alterações metabólicas e um discreto depósito de ferro hepático. O método padrão ouro para o diagnóstico de sobrecarga de ferro é a biópsia hepática. Por se tratar de método invasivo, novos métodos se tornam necessários. Dentre eles a ressonância nuclear magnética (RM) é o mais disponível. Pacientes e Métodos: O presente estudo avaliou pacientes com HF, excesso de peso, e DHGNA comprovada por biópsia hepática. Os pacientes realizaram RM pela técnica de relaxometria (análise de gordura/ferro - máquina 3T), dosagem de marcadores inflamatórios (IL-6 e TNF-alfa), análise da expressão das subunidades da ferritina (FP - cadeia pesada e FL - cadeia leve) e dosagem de hepcidina. Os dados foram comparados com a biópsia hepática. Estes pacientes foram classificados segundo os níveis de ferritina e siderose. Foram classificados em ferritina normal (FN), hiperferritinemia dismetabólica (HFD) e SDDF. O grupo de FN foi caracterizado por ferritina < 200 ng/mL em mulheres e 300 ng/mL em homens, já os pacientes do grupo HFD têm níveis elevados de ferritina e ausência de siderose hepática. Os pacientes também foram avaliados considerando somente a siderose hepática. Resultados: Foram avaliados 152 pacientes com DHGNA comprovada pela biópsia hepática, sendo 67 incluídos no estudo. A frequência de SDDF e HFD foi de 37% e 16%, respectivamente. O nível de corte da ferritina sérica, a fim de identificar depósito de ferro, foi de 180.4 ng/mL para mulheres (sensibilidade de 76,9%, especificidade de 64,3%) e 350,7 ng/mL para homens (sensibilidade de 72,7% e especificidade de 75,5%). Os pacientes com SDDF E HFD não apresentaram piores características metabólicas e histológicas. Os níveis de hepcidina foram maiores nos grupos SDDF E HFD, se correlacionando com o conteúdo de ferro hepático quando > 30,2 ng/mL. Os marcadores inflamatórios (IL-6 e TNF-alfa) foram semelhantes entre os grupos. A expressão de FP e FL se comportaram de modo semelhante entre os grupos. A FL se correlacionou com síndrome metabólica e circunferência abdominal, enquanto a FP se correlaciona com níveis maiores de esteatose. A RM foi capaz de identificar o conteúdo de ferro destes pacientes, sendo o ponto de corte de R2* 58,9s-1. A porcentagem de gordura, identificada pela RM, foi de 17% nos grupos HFD e SDDF e de 13% no grupo FN. Conclusão: 1) RM utilizando a técnica de relaxometria com correção da interferência de gordura se mostrou acurado na avaliação de discreto depósito de ferro em pacientes com SDDF; 2) HF pode refletir depósito de ferro hepático quando acima de 180,4 ng/mL para mulheres e 350,7 ng/mL para homens, não foi encontrada relação entre HF e características piores metabólicas ou histológicas; 3) FL se correlacionou com síndrome metabólica e circunferência abdominal, enquanto a FP se correlaciona com esteatose; 4) Hepcidina se correlacionou com siderose e ferritina sérica nos pacientes com DHGNA / Introduction: Hyperferritinemia (HF) may reflect the inflammatory status of patients with NAFLD and obesity, but about 33 % reflects a real hepatic iron overload. The dysmetabolic iron overload syndrome (DIOS) definition is HF, normal transferrin saturation, and mild hepatic iron overload in a patient with metabolic disorders. The gold standard for diagnosis of iron overload is the liver biopsy. As it is an invasive method, new methods are necessary. Among them, magnetic resonance imaging (MRI) is the most available one. Patients and Methods: This study evaluated patients with HF, overweight and NAFLD. All patients were submitted to liver biopsy. MRI relaxometry (fat/iron analysis - 3T machine), measurement of inflammatory markers (TNF-alpha and IL-6), analysis of the expression of ferritin light and heavy chain subunits (FL and FP) and serum hepcidin were held. Data were correlated with liver biopsy. The patients were classified considering the ferritin levels and siderosis. They were classified in three groups: normal ferritin (NF), dysmetabolic hyperferrinemia (DHF) and DIOS. The NF group has serum ferritin (SF) below 200 ng/dL for women and 300 ng/dL for men, DHF must have SF above those values and negative siderosis, and DIOS have hyperferritinemia and positive siderosis. They are also classified considering only the iron status Results: 152 biopsy-proven NAFLD patients were screened but only 67 were included in this study. DIOS and HFD frequency in our sample were 37% and 16%, respectively. The cut-off of ferritin levels were correlated with iron overload in liver biopsy was 180.4 ng/mL for women (sensibility of 76.9% and specificity of 64.3%) and 350 ng/mL for men (sensibility of 72.7% and specificity of 75.5%). Although, DHF and DIOS patients did not have worst metabolic or histological characteristics, hepcidin levels were higher in DHF and DIOS groups, correlating with hepatic siderosis when hepcidin is above 30,2 ng/mL. The inflammatory markers (IL- 6 and TNF-alpha) were similar among the groups. The expression of FP and FL were similar in role sample. FL correlates with metabolic syndrome and abdominal circumference, while FP correlates with in higher fat scores. The MRI was able to identify mild iron overload. The R2* cut off level was 58,9 s -1. The fat percentage in DIOS and HFD was of 17% each and in NF 13%. Conclusion: 1) MRI using relaxometry method is accurate to evaluate mild iron overload in DIOS patients; 2) HF may reflect iron overload when above 180.4 ng/mL for women and 350.7 ng/mL for men, however, this study didn´t find correlation between HF and insulin resistance and worst NAFLD histological characteristics; 3) FL correlates with metabolic syndrome and abdominal circumference while FP correlates with in higher fat scores 4) Hepcidin correlates with iron and serum ferritin in NAFLD patients

Introdução: A obesidade é uma doença crônica que aumenta sua prevalência progressivamente no mundo todo. Uma das suas principais complicações é a doença hepática gordurosa não alcoólica (DHGNA), que pode apresentar-se de forma assintomática, com esteatose hepática, esteato-hepatite, cirrose e hepatocarcinoma. Está associada à dislipidemia, hipertensão, diabetes, síndrome metabólica e resistência insulínica. O padrão ouro para seu diagnóstico é a biopsia hepática, considerado método invasivo. Medidas indiretas são usadas para auxiliar na sua detecção, como dados do exame físico, exames de bioquímica e de imagem. Objetivo: Diagnosticar DHGNA usando a ressonância nuclear magnética (RNM) como método não invasivo, correlacionando-a com achados clínicos e laboratoriais. Metodologia: Estudo transversal de 50 crianças e adolescentes seguidas no Ambulatório de Obesidade do Hospital das Clínicas da FMRP-USP. Foram submetidas à questionário sobre histórico pessoal e familiar, à exame físico, exames laboratoriais (lipidograma, transaminases, glicemia e insulina basal) e RNM de abdome para cálculo da de gordura hepática, visceral e subcutânea. Resultados: Diagnosticado esteatose hepática em 14 (28%) dos participantes, sendo 8 com esteatose grave (porcentagem de gordura >18%) e 4 não grave (porcentagem gordura hepática entre 9 e 18%). Houve diferença estatisticamente significante entre a gordura hepática detectada pela RNM e o gênero masculino, triglicérides, TGO, TGP, relação TGO/TGP e acantose nigricans. O cálculo do Homeostasis Model Assessment Insulin Resistance (HOMA-IR) e da síndrome metabólica não apresentaram relação positiva com a porcentagem de gordura hepática. Conclusão: A frequência de esteatose hepática, utilizando a RNM como ferramenta diagnóstica, foi inferior à encontrada na literatura. Dos parâmetros estudados, os melhores preditores de esteatose hepática foram triglicérides, TGO, TGP, relação TGO/TGP, gênero masculino, acantose nigricans e Z escore para IMC elevado / Introduction: Obesity is a chronic disease whose prevalence progressively increasing worldwide. One of its main complications is non-alcoholic fatty liver disease (NAFLD), which may occur in an asymptomatic form, as simple fatty liver, steatohepatites (NASH), cirrhosis and hepatocellular carcinoma. This disease is associated with dyslipidemia, hypertension, diabetes, metabolic syndrome and insulin resistance. The gold standard for diagnosis is a liver biopsy, considered to be an invasive method. Indirect measures are used to aid its diagnosis, such as physical, biochemical and imaging tests. Objective: Diagnosing NAFLD using MRI as non-invasive method and correlating it with clinical and laboratory findings. Methodology: A cross-sectional study of 50 children and adolescents followed at the Obesity clinic of the University Hospital, FMRP-USP. A questionnaire about personal and family history was aplplied and each subject was submitted to physical examination, laboratory tests (lipip profile, transaminases, glycemia and basal insulin) and magnetic resonance imaging (MRI) of the abdomen for calculation of hepatic, visceral and subcutaneous fat. Results: Fatty liver disease was diagnosed in 14 (28%) of the participants, 8 of them with severe steatosis (fat percentage > 18%) and 4 with milder steatosis (fat percentage between 9 and 18%). There was a statistically significant difference between the hepatic fat detected by MRI and male gender, triglycerides, AST, ALT, AST/ALT ratio and acanthosis nigricans. The calculation of the Homeostasis Model Assessment Insulin Resistance (HOMA-IR) and of the metabolic syndrome did not show a positive relationship with the percentage of hepatic fat. Conclusion: The frequency of hepatic steatosis using MRI as a diagnostic tool, was lower than the values reported in the literature. Among the parameters studied, the best predictors of liver steatosis were triglycerides, AST, ALT, AST/ALT ratio, male gender, acanthosis nigricans and Z score for high body mass index