Diss. (sammanfattning) Umeå : Umeå universitet, 2008. / På titelsidan felaktigt: "... amylodosis" Härtill 4 uppsatser.

No description available.

Wild-type transthyretin amyloidosis (ATTRwt) is a rare, sporadic protein misfolding disorder with no validated biomarkers or specific treatments. The disease is characterized by deposition of amyloid fibrils composed of wild-type transthyretin (TTR) in cardiac tissue, which leads to cardiomyopathy, heart failure, and death within 5 years. The hypothesis for the studies detailed in this dissertation was non-coding variants in the TTR gene regulatory regions impact expression and serum levels of the protein, thereby contributing to ATTRwt pathogenesis. Investigations included examination of 2 enhancer regions and the proximal promoter of the TTR gene for risk factors which could contribute to pathogenesis of ATTRwt amyloidosis. In total, 11 common and 20 rare variants were identified. The analyses demonstrated significant associations of 3 variants with increased disease risk and 4 variants with age at disease onset and/or survival. Functional studies using GFP and luciferase reporter assays in HepG2 cells were performed to examine the impact of nucleotide alterations in the TTR proximal promoter on reporter expression. Three ATTRwt-risk factors (rs3764479, rs72922940, rs3794885), caused significantly decreased reporter expression in both GFP and luciferase assays (p < 0.02). Moreover, serum TTR levels, measured by immunoturbidity and analyzed along with ATTRwt clinical data, demonstrated that lower serum TTR concentrations were associated with worse survival (hazard ratio = 0.89, p = 0.003). Follow-up analysis of an ATTRwt subset treated with diflunisal, a TTR stabilizer, showed increased serum TTR (p = 0.002) and organ improvement as assessed by cardiac biomarkers (p = 0.043). Unexpectedly, our genetic sequencing data suggested that the TTR G6S variant was disease-protective. Analysis of the TTR G6S protein using circular dichroism and aggregation assay corroborated these findings by demonstrating a higher structural stability and a lower aggregation propensity compared to L55P and V122I, two unstable amyloidogenic TTR variants. In summary, the major findings of this work were: 1) identification of genetic variants that confer risk for ATTRwt amyloidosis through changes in expression, 2) evidence in support of serum TTR as a candidate for monitoring disease progression and response to treatment, and 3) evidence suggesting that TTR G6S may confer protection from ATTRwt by slowing the amyloid cascade. / 2017-09-08T00:00:00Z

Diss. (sammanfattning) Umeå : Univ., 2004. / Härtill 3 uppsatser.

BACKGROUND: Studies in various chronic diseases have correlated health-related quality of life (HRQOL) with disease state and treatment outcomes. Limited data exists on the association between HRQOL, survival, and clinical biomarkers of disease in wild-type and familial TTR amyloidosis (ATTRwt & ATTRm) patient populations. OBJECTIVES: To assess the association between HRQOL and survival, as well as HRQOL and clinical biomarkers of disease in transthyretin-mediated amyloidosis (ATTR) patient populations. METHODS: Using a retrospective cohort study design, HRQOL was assessed via SF-36 health surveys collected from patients with ATTRwt and ATTRm presenting for their initial evaluation at the BU Amyloidosis Center between 1985 and 2015. Kaplan-Meier curves and hazard ratios (HRs) calculated using Cox proportional hazards regression analysis were used to examine the association between physical (PCS) and mental (MCS) component scores derived from the SF-36 health surveys and survival follow-up. All analyses were adjusted for potential confounders such as age at presentation, gender, and co-morbidities including diabetes mellitus, hypertension and hyperlipidemia. Spearman’s rank correlations were calculated to assess the association between PCS, MCS and clinical biomarkers of disease (mBMI, troponin I and BNP) also collected at time of initial evaluation visit. Statistical significance was set at a two-sided alpha=0.05. RESULTS: In the ATTRwt cohort, 133 white males, aged 74.6 +/- 6.0 years (mean + SD) presented with mean MCS (45.7 +/- 12.3) and PCS (36.7 +/- 10.8) that were respectively, 0.5 and 1.5 SD below 50. Patients with PCS or MCS scores < 35 had a significantly higher risk of death during follow-up than those with scores >= 35 for PCS (HR=2.45; p=0.002) and for MCS (HR=3.38, p<0.0001). BNP and troponin I associated with MCS (r= - 0.24; p=0.01 and p=0.02, respectively) and PCS (r= - 0.29; p=0.002 and r= - 0.25; p=0.012, respectively). In the ATTRm cohort, 331 white (82%) males (67%), aged 57.5 +/- 13.9 years presented with mean MCS (45.2 +/- 11.7) and PCS (37.2 +/- 13.3). Patients with PCS scores < 35 had a significantly higher risk of death during follow-up than those with scores >= 35 (HR=2.76; p= <0.0001). In contrast, MCS scores < 35 did not correlate with increased risk of death during follow-up (HR=1.38, p=0.13). BNP and troponin I most strongly associated with PCS (r= - 0.50; p<0.0001 and r= - 0.41; p<0.0001, respectively) and less with MCS (r= - 0.16; p=0.03 and r= - 0.24; p=0.007, respectively). mBMI did not associate with MCS or PCS in the ATTRwt and ATTRm cohorts. CONCLUSIONS: ATTR disease significantly decreased an individual’s physical and mental HRQOL. PCS and MCS were shown to be independent predictors of mortality but their ability to predict survival varied by cohort. Assessment of HRQOL may provide valuable prognostic information that could be of use in the management of ATTR disease.

Recent work in humans with protein losing nephropathies has revealed increased urine concentrations of sulfated glycosaminoglycans (GAGs). Differences exist between normal patients, those with glomerulonephritis (GN), and those with amyloidosis thus potentially allowing differentiation without a renal biopsy. Aims of this study were to validate a simple spectrophotometric assay used to measure canine urinary GAGs, establish a normal reference range, and determine optimal storage conditions. Urine GAG concentrations were measured in a limited number of dogs with glomerulonephritis or amyloidosis. Fourteen healthy dogs were placed in metabolic cages and all urine was collected for 24 hours. Serum and urine creatinine concentrations were measured at the beginning and end of the collection period. Urine collected at the beginning of the 24-hr period was centrifuged and the supernatant used to measure a spot GAG concentration and a spot glycosaminoglycan to creatinine ratio (GCR). A well mixed aliquot of the 24-hr sample was centrifuged, the supernatant used to measure the 24-hr total GAG, and stored at 4°C and -20°C for 1, 7, and 30 days. All dogs were used to determine effects of time and temperature (n=14), however, only dogs with an endogenous creatinine clearance > 2 ml/min/kg (n=10) were used to determine normal values. A standard absorption curve using a 1,9-dimethlymethylene blue dye and dilutions of chondroiton-4-sulfate was developed to estimate total GAG concentration. Repeated measures analysis of variance was used to test for effects of storage temperature and time on stability of urinary GAG. A p-value of < 0.05 was considered significant. Relationships between spot urinary GAG concentration, spot urinary GAG to creatinine ratio (GCR) and 24-hr total GAG excretion were estimated using simple linear regression. Single urine samples were collected by cystocentesis from dogs with GN or renal amyloidosis. The diagnosis was confirmed by clinical evaluation or by histologic analysis. Urine protein, creatinine and GAG concentrations were measured. There were no time or temperature effects on urine GAG concentrations for up to 1 day at 4°C and 30 days at -20°C. Mean 24-hr total GAG excretion ± standard deviation was 1.586 ± 0.461 mg/kg of body weight. Mean spot GAG concentration and spot GCR were 5.007 ± 1.588 mg/dl and 0.023 ± 0.01 respectively. Neither spot GAG concentration (R2=0.4216) nor GCR (R2= 0.0839) were adequate predictors of 24-hr total GAG. The GCR's from dogs with renal disease were not different from normal dogs. This study established normal total urinary GAG values in dogs. Contrary to findings in humans, there was no correlation between 24-hr total sulfated GAG and spot GCR in dogs, limiting clinical utility of this test. Further work is needed to determine if either total sulfated GAG or the spot GCR can be used to differentiate causes of protein-losing nephropathies in dogs. / Master of Science

Introduction: Waldenström's macroglobulinemia is a hematological neoplasm belonging to the group of monoclonal gammopathies, which includes systemic symptoms and those related to an increase in M paraprotein. Objective: To describe a case of cardiac amyloidosis associated with macroglobulinemia. Clinical case: Male patient who was admitted for asthenia, dysphonia, and who, during his evolution, developed progressive dyspnea, heart failure and pleural effusion. Additionally, echocardiography showed myocardial granular pattern, while pleural biopsy was positive for Congo red staining. Subsequently, he received treatment with bortezomib, dexamethasone and rituximab, with favorable evolution. Conclusions: In this disease, early diagnosis is an important advantage for survival. Therefore, its management is palliative of cardiac manifestations. The present case shows a diagnostic challenge, in which the less frequent etiologies of heart failure must be taken into account. / Revisión por pares

No description available.

No description available.

Although a rare disease, light chain (LC) amyloidosis (AL) is the most common systemic amyloidosis in developed countries. It is caused by an overproduction of immunoglobulin LC proteins in bone marrow plasma cells. In AL amyloidosis, LCs that are prone to misfolding and insolubility will aggregate, form fibrils, and deposit themselves in various tissues, thereby causing organ dysfunction. The most fatal manifestation of AL amyloidosis is associated with cardiac involvement, defined by the presence of extracellular AL amyloid deposits within the heart. Cardiac amyloid infiltration typically leads to diastolic dysfunction followed by heart failure and has a median survival of approximately 6 months from the time of diagnosis if untreated. Clinical observation suggests that a reduction in circulating LCs results in an improvement in heart failure symptoms despite minimal changes in amyloid deposition. This has led to the concept that LCs themselves are cytotoxic to cardiomyocytes. Recent studies indicate that AL LCs induce oxidative stress, cellular dysfunction, and apoptosis (programmed cell death) in cardiomyocytes via a p38α mitogen-activated protein kinase (MAPK) mechanism. They may therefore be a target for amyloidosis therapy. By understanding how LCs cause cardiac dysfunction, we can target this process with therapies and utilize downstream measures of LC activity as diagnostic and prognostic tools. The objective of this study was to determine the role of autophagy in AL amyloidosis. Autophagy is the intracellular process of degrading aging or dysfunctional cellular components. Autophagy can be beneficial by preventing proteotoxicity and providing nutrients, amino acids, and other necessities during times of cellular stress. On the other hand, increased autophagy, like apoptosis, may mediate cellular death depending on the type of stimulus and its duration. Autophagy is induced by a variety of stimuli, including oxidative stress. AL has been demonstrated to increase reactive oxygen species (ROS), and it is unknown if autophagy mediates cardiomyocyte dysfunction in AL cardiac amyloidosis. We thus sought to determine if it is a factor in amyloid cardiotoxicity. We explored the ERK1/2, p38, and JNK MAPK pathways in particular, since MAPK signaling cascades regulate several transcription factors involved in the cell cycle and p38α has been implicated in ROS-induced cardiac AL amyloidosis. Adult rat ventricular myocytes (ARVM) were harvested from healthy adult male rats and exposed to a variety of experimental conditions in vitro. ARVM were treated with vehicle control, human LC obtained from a patient without cardiac involvement, a positive control (aldosterone), and human AL light chains obtained from a patient with AL cardiac amyloidosis in the presence or absence of UO126, SB203580, or SP600125 (specific inhibitors of ERK1/2, p38, and JNK, respectively). The resulting protein expression levels of autophagy indicators LC3II and ATG4B in cardiomyocytes were analyzed by Western blotting. The ratio of phosphorylated to total ERK1/2 protein expression was also explored. We found that AL light chains did not contribute to autophagy via the ERK1/2, p38, or JNK pathways. In contrast to our previous unpublished findings, the protein levels of autophagy indicators in AL-treated ARVM did not differ from vehicle control levels, suggesting that AL did not activate autophagy. However non-cardiomyopathic light chains (LC) did increase LC3II expression in ARVM, despite their human source exhibiting no clinical indications of cardiac involvement. This implies that autophagy induced by non-cardiomyopathic LCs may be beneficial and protect against the development of the cardiotoxicity seen in AL cardiac amyloidosis. Further studies are necessary to understand the effect of autophagy in the heart and its role in cardiac amyloidosis. Continuing to explore the underlying mechanisms of AL light chain toxicity will contribute to the development of diagnostic, prognostic, and treatment strategies for AL amyloidosis.