Ziel dieser Arbeit war es herauszufinden, ob es sich bei der leukozytoklastischen Zelldesintegration der neutrophilen Granulozyten in kutaner leukozytoklastischer Vaskulitis (kLV) um Apoptose handelt. Um die zugrundeliegenden Mechanismen dieses Zellzerfalls näher zu charakterisieren, wurden Hautbiopsien von 9 Patienten mit klinisch und histologisch gesicherter kLV und 13 Hautbiopsien von Patienten mit kLV folgend auf intrakutane Histamin-Injektion im zeitlichen Verlauf untersucht. Licht und elektronenmikroskopisch wurde die Morphologie der Leukozytoklasie beurteilt. Immunhistologische Untersuchungen beinhalteten klassische pro-apoptotische Rezeptoren (CD95/CD95L), desweiteren über die Mitochondrien (Bax/Bcl-2) und auf genetischer Ebene die Apoptose regulierende Proteine (p53/p21). Es wurde zusätzlich die Expression von Zelloberflächen-Rezeptoren (FcgammaRIII/ FcgammaRII) beurteilt. Mittels der TUNEL-Methode wurde versucht die klassische DNA-Fragmentierung nachzuweisen. Obwohl strukturell und ultrastrukturell die klassischen morphologischen Merkmale der Apoptose vorlagen, konnte diese biochemisch nicht untermauert werden. DNA-Fragmentierung liess sich nur in schon von Makrophagen phagozytierten Kernfragmenten nachweisen. Neutrophile waren negativ und ihre Fragmente waren es vorwiegend. Den untersuchten Rezeptoren CD95/CD95L kommt allenfalls eine geringe und den Proteine, Bax/Bcl-2 und p53/p21 keine Rolle im Zellzerfall der Neutrophilen in dieser selbstlimitierten Entzündung zu. Interessanterweise wurde jedoch FcgammaRIII sehr stark auf der Oberfläche nicht nur intakter, sondern auch schon fragmentierter neutrophiler Granulozyten exprimiert. Dementsprechend ist anzunehmen, dass diese konstitutionell exprimierten Rezeptoren nicht nur eine Rolle in der Aktivierung, sondern auch eine Rolle in der darauf folgenden Auslösung der Apoptose in diesen Zellen spielen. Desweiteren dienen diese stark glykosylierten Rezeptoren möglicherweise als Phagozytose-Erkennungsmerkmal für Makrophagen. FcgammaRII liess sich hingegen nicht auf der Oberfläche der Neutrophilen und ihrer Fragmente nachweisen. Dies könnte einerseits durch eine Verdrängung durch FcgammaRIII bedingt sein, andrerseits könnten sie durch Immnunkomplex-Bindung eine separate oder zusätzliche Rolle in der Induktion des Zellzerfalls spielen. Zusammenfassend weist der leukozytoklastische Zellzerfall der Neutrophilen in kLV die klassischen morphologischen Merkmale der Apoptose auf, die biochemisch jedoch auf atypische Weise abläuft. In dieser Hinsicht zu erwähnen, ist vor allem die verzögerte oder durch DNasen der Makrophagen bedingte DNA-Fragmentierung. / The aim of this study was to find out whether leukocytoklastic cell desintegration of neutrophils in cutaneous leukocytoklastic vasculitis (clv) is apoptosis. In order to find out more about the underlying mechanisms leading to this form of cell desintegration and subsequent cell death skin sections of 9 patients with clinically and histologically verified clv and of 13 patients with clv after intradermal injection of histamine were examined at different timepoints. The structural and ultrastructural morphological features of leukoctyoklasia were evaluated light- and electronmicroscopically. Immunhistochemistry included well known death receptors (CD95/CD95L), mitochondrial proteins (Bax/Bcl-2), proteins interfering with the cell cycle (p53/p21) and cell surface receptors (FcgammaRIII/FcgammaRII). Furthermore DNAfragmentation was assessed by the TUNEL-method. Although the structural and ultrastructural features of leukocytoklastic cell desintegration of neutrophils in clv revealed typical apoptotic morphology, the underlying biochemistry didn`t match apoptotic means. DNA-fragmentation was only seen in a minor fraction of fragmented nuclei and prominent in already phagocytosed debris. Neutrophils at different locations (in the lumen of the postcapillary venules, within the wall of the blood vessels and in the perivascular tissue) were always negative.The examined death receptors, mitochondrial proteins and DNA-interfering proteins play no (Bcl-2/Bax, p53/p21) or only a minor (CD95/CD95L) role in the biochemical mechanism leading to the cell desintegration of these cells in this self-limited inflammation. Interestingly FcgammaRIII was highly expressed not only in intact but also extremely desintegrated neutrophils as well as on the surface of their fragments. One could therefore assume that this receptor not only plays a role in activation of these cells, but also might be involved in the following induction of the cell death programm. Maybe this highly glycosylated receptor also functions as an `eat me flag` in the recognition-mechansim by macrophages. FcgammaRII could not be shown on the cell surface of these cells in this context, which on the one hand could be due to the high expression of FcgammaRIII with no room left for FcgammaRII on the cell surface or due to a separate or additional role in the induction of the cell death programm. Finally leukocytoklastic cell desintegration shows strong resemblance to apoptosis but with non classical underlying biochmical mechanisms, most importantly to mention the delay in DNA-fragmentation which could also be due to DNAdegradation by DNases of macrophages.

Objetivo: Avaliar marcadores de reserva ovariana e a presença de anticorpo anti-corpo lúteo (anti-CoL) em pacientes com arterite de Takayasu (AT) e possível associação com parâmetros clínicos, laboratoriais e uso de imunossupressores. Métodos: 20 pacientes com AT e 24 controles saudáveis foram avaliados para anti-CoL (immunoblot). A reserva ovariana foi avaliada por: hormônio folículo estimulante (FSH), hormônio luteinizante (LH), estradiol, hormônio anti-Mülleriano (HAM) e contagem de folículos antrais (CFA). HAM foi dosado por ELISA utilizando dois diferentes testes. Dados demográficos, obstétricos, alterações menstruais, aspectos clínicos, imagens vasculares e tratamento foram também analisados. Resultados: A média da idade atual foi similar em pacientes e controles (31,2 ± 6,1 vs. 30,4 ± 6,9 anos, p = 0,69). As frequências de HAM baixo foram idênticas em pacientes com AT com ambos os testes de ELISA e maiores quando comparadas ao grupo controle (50% vs.17%, p=0,02, 50% vs. 19%, p=0,048). Observou-se uma correlação positiva entre os dois testes de ELISA em pacientes (r=0,93, p < 0,0001) e em controles saudáveis (r=0,93, p < 0,0001). Pacientes com AT apresentaram menor CFA (11 vs. 16, p=0,13) e maior frequência de CFA reduzida (41% vs. 22%, p=0,29), contudo sem significância estatística. Não foram encontradas diferenças entre os dois grupos em relação às outras características demográficas e clínicas, dados obstétricos e demais parâmetros da reserva ovariana (p > 0,05). Anti-CoL foi observado apenas em uma paciente com AT (5% vs. 0%, p = 0,45). Avaliação adicional das mulheres com AT comparando as com baixos níveis de HAM ( < 1,0 ng/mL) versus aquelas com níveis de HAM QRUPD ng/mL) não mostrou diferença entre os dois grupos em relação a duração da doença, atividade de doença, provas de fase aguda, exames de imagem vascular e tratamento (p > 0,05). Conclusão: O presente estudo foi o primeiro a sugerir que as pacientes com AT podem apresentar reserva ovariana diminuída / Objective: To assess ovarian reserve markers and anti-corpus luteum antibodies (anti-CoL) in Takayasu arteritis (TA) patients and a possible association with clinical and laboratory parameters and the use of immunosuppressive drugs. Methods: 20 TA and 24 healthy controls were evaluated for anti-CoL (immunoblot). Ovarian reserve was assessed by: follicle stimulating hormone (FSH), luteinizing hormone (LH), estradiol, antiMüllerian hormone (AMH) and antral follicle count (AFC). AMH was measured by ELISA using two different kits. Demographical data, menstrual abnormalities, obstetric data, clinical features, vascular imaging and treatment were also analyzed. Results: The mean current age was similar in TA patients and controls (31.2 6.1 vs. 30.4 6.9 years, p=0.69). The frequencies of decreased levels of AMH in TA patients were identical using both kits and higher when compared to controls (50% vs. 17%, p=0.02; 50% vs. 19%, p=0.048). A positive correlation was observed between the two kits in TA patients (r=+0.93; p < 0.0001) and in healthy controls (r=+0.93; p < 0.0001). The apparent lower AFC (11 vs. 16, p=0.13) and the higher frequency of low AFC (41% vs. 22%, p=0.29) in TA compared to controls did not reach statistical significance. No differences between the two groups were found concerning other demographic and clinical characteristics, obstetric data and other parameters of ovarian reserve (p > 0.05). Anti-CoL was solely observed in TA patients (5% vs. 0%, p=0.45). Further evaluation of TA patients comparing patients with low AMH levels ( < 1.0ng/mL) versus normal AMH levels (.- 1.0ng/mL) revelead no differences regarding disease duration, disease activity, acute phase reactants, vascular imaging and treatment between these two groups (p > 0.05). Conclusions: The present study was the first to suggest that TA patients may have diminished ovarian reserve

Objetivo: Avaliar marcadores de reserva ovariana e a presença de anticorpo anti-corpo lúteo (anti-CoL) em pacientes com arterite de Takayasu (AT) e possível associação com parâmetros clínicos, laboratoriais e uso de imunossupressores. Métodos: 20 pacientes com AT e 24 controles saudáveis foram avaliados para anti-CoL (immunoblot). A reserva ovariana foi avaliada por: hormônio folículo estimulante (FSH), hormônio luteinizante (LH), estradiol, hormônio anti-Mülleriano (HAM) e contagem de folículos antrais (CFA). HAM foi dosado por ELISA utilizando dois diferentes testes. Dados demográficos, obstétricos, alterações menstruais, aspectos clínicos, imagens vasculares e tratamento foram também analisados. Resultados: A média da idade atual foi similar em pacientes e controles (31,2 ± 6,1 vs. 30,4 ± 6,9 anos, p = 0,69). As frequências de HAM baixo foram idênticas em pacientes com AT com ambos os testes de ELISA e maiores quando comparadas ao grupo controle (50% vs.17%, p=0,02, 50% vs. 19%, p=0,048). Observou-se uma correlação positiva entre os dois testes de ELISA em pacientes (r=0,93, p < 0,0001) e em controles saudáveis (r=0,93, p < 0,0001). Pacientes com AT apresentaram menor CFA (11 vs. 16, p=0,13) e maior frequência de CFA reduzida (41% vs. 22%, p=0,29), contudo sem significância estatística. Não foram encontradas diferenças entre os dois grupos em relação às outras características demográficas e clínicas, dados obstétricos e demais parâmetros da reserva ovariana (p > 0,05). Anti-CoL foi observado apenas em uma paciente com AT (5% vs. 0%, p = 0,45). Avaliação adicional das mulheres com AT comparando as com baixos níveis de HAM ( < 1,0 ng/mL) versus aquelas com níveis de HAM QRUPD ng/mL) não mostrou diferença entre os dois grupos em relação a duração da doença, atividade de doença, provas de fase aguda, exames de imagem vascular e tratamento (p > 0,05). Conclusão: O presente estudo foi o primeiro a sugerir que as pacientes com AT podem apresentar reserva ovariana diminuída / Objective: To assess ovarian reserve markers and anti-corpus luteum antibodies (anti-CoL) in Takayasu arteritis (TA) patients and a possible association with clinical and laboratory parameters and the use of immunosuppressive drugs. Methods: 20 TA and 24 healthy controls were evaluated for anti-CoL (immunoblot). Ovarian reserve was assessed by: follicle stimulating hormone (FSH), luteinizing hormone (LH), estradiol, antiMüllerian hormone (AMH) and antral follicle count (AFC). AMH was measured by ELISA using two different kits. Demographical data, menstrual abnormalities, obstetric data, clinical features, vascular imaging and treatment were also analyzed. Results: The mean current age was similar in TA patients and controls (31.2 6.1 vs. 30.4 6.9 years, p=0.69). The frequencies of decreased levels of AMH in TA patients were identical using both kits and higher when compared to controls (50% vs. 17%, p=0.02; 50% vs. 19%, p=0.048). A positive correlation was observed between the two kits in TA patients (r=+0.93; p < 0.0001) and in healthy controls (r=+0.93; p < 0.0001). The apparent lower AFC (11 vs. 16, p=0.13) and the higher frequency of low AFC (41% vs. 22%, p=0.29) in TA compared to controls did not reach statistical significance. No differences between the two groups were found concerning other demographic and clinical characteristics, obstetric data and other parameters of ovarian reserve (p > 0.05). Anti-CoL was solely observed in TA patients (5% vs. 0%, p=0.45). Further evaluation of TA patients comparing patients with low AMH levels ( < 1.0ng/mL) versus normal AMH levels (.- 1.0ng/mL) revelead no differences regarding disease duration, disease activity, acute phase reactants, vascular imaging and treatment between these two groups (p > 0.05). Conclusions: The present study was the first to suggest that TA patients may have diminished ovarian reserve

A Aspergilose Broncopulmonar alérgica (ABPA) é uma doença complexa,desencadeada por uma reação de hipersensibilidade ao Aspergillus fumigatus, que apresenta vários estágios, sendo que no estágio mais grave, os pacientes apresentam bronquiectasias. O diagnóstico da doença é difícil e o maior problema é a falta de antígenos padronizados necessários para a determinação de anticorpos específicos. O objetivo do presente estudo é avaliar se os testes cutâneos com os análogos de Asp f 1 podem auxiliar no diagnóstico e no estadiamento da ABPA. Três grupos de pacientes classificados por testes sorológicos foram obtidos a saber 20 ABPA (16BQ+; 4BQ-), 25 possíveis -ABPA (14BQ+;11BQ-) e 24 asmáticos sem ABPA (11BQ+;13BQ-). Fizeram parte do estudo 10 pessoas sem asma . Todos foram submetidos a testes intradérmicos com três antígenos a-sarcina, mitogilina e estrictocina.Houve uma intensa reação a todos os antígenos e as reações produzidas foram semelhantes para os três antígenos. As reações de leitura tardia positivas à mitogilina foram biopsiadas. As biopsias de 2 (12,5%) dos pacientes BQ+ do grupo ABPA e 5 do grupo ABPA possível com BQ+ (35,6%) mostraram vasculite por depósito de imunocomplexos. 11 pacientes do terceiro grupo não apresentaram vasculite. O quarto grupo não apresentou reação tardia. Todos os pacientes com reação positiva apresentaram BQ+. alfa-sarcina, a mitogilina e a restrictocina diferenciaram pacientes com ABPA por testes intradérmicos e podem ser aplicados no diagnóstico da doença. A maior incidência de bronquiectasias foi encontrada no primeiro grupo (80%) e no segundo (56%). No terceiro grupo nenhum caso foi encontrado em 23 pacientes com asma e teste ID positivo ao aspergillus fumigatus todos os pacientes com vasculite tinham bronquiectasia. Há possibilidade de que as lesões produzidas nos pulmões sejam produzidas por vasculite. / Allergic Bronchopulmonary Aspergillosis (ABPA) is a complex disease, triggered by a hypersensitivity reaction to Aspergillus fumigatus. The disease diagnosis is difficult, and a major problem is the lack of standardized allergens for the determination of specific antibodies. The aim of the present study is to evaluate if intradermal (ID) tests with analogs of Asp f 1 can aid in the diagnosis and stage assessment of abpa. Three groups of patients classified by serological tests were obtained. 20 ABPA (16BQ+; 4BQ-), 25 possible-ABPA (14BQ+; 11BQ-), 24 asthmatic-ABPAfree (11BQ+; 13BQ-) and 10 asthma-free people were submitted to id tests with three antigens: mitogillin, a-sarcin and restrictocin. There was intense reaction to all three antigens and the response was similar. The positive reactions to mitogillin were biopsied. The skin biopsies of two (12,5%) bq+ patients of the first group and 5 BQ+ (35,6%) patients of the second one showed vasculitis by immune complexes (IC) deposition. 11 patients of the third group had negative biopsies. The fourth group didn\'t have late-reaction. All patients with positive reaction were BQ+. By ID test, alfa-sarcin, mitogillin and restrictocin could differentiate patients with abpa and can be applicable in disease diagnosis. The higher incidence of bronchiectasis was found in the first (80%) and second (56%) groups. In the third group, IC wasn\'t found in 23 asthma patients and id test was positive to A. fumigatus. All patients with vasculitis by IC had bronchiectasis. Therefore, the results indicate that this kind of pulmonary lesion is caused by vasculitis.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This doctoral thesis involved the study of ocular and periocular diseases affecting domestic animals, and included one manuscript about lesions of surgical pathology and one manuscript about hyphema in dogs and cats submitted to necropsy. In the first part, 33,075 reports of hystopathological exams performed in a veterinary pathology diagnostic laboratory in the Central Region of the State of Rio Grande do Sul, Brazil, over 50 years. From the total amount, 540 (1.6%) concerned ocular and periocular lesions. For various reasons ninety specimens were excluded from the study, 450 remaining. More than half of all cases consisted of samples from dogs (53.5%), followed by cattle (28.2%), cats (11.1%), horses (5.1%) sheep (1.3%), rabbits (0.4%), and pig (0.2%). The eyelids were the most prevalent (248/450) site of lesions in each of the species studied, followed by third eyelid (73/450), and conjunctiva (27/450). In dogs lesions in sebaceous glands were the most common findings (75/241), followed by melanocytic tumors and nonspecific conjunctivitis. In cattle, anatomical sites affected by ocular and periocular lesions, in decreasing order of frequency, were eyelid, cornea and third eyelid. Squamous cell carcinoma (SCC) alone accounted for 80.3% of all lesions diagnosed in cattle. Neoplasia accounted for most of the lesions diagnosed in cats (39/50 cases); all of these were malignant, and SCC, hemangiosarcoma and fibrosarcoma were the most common types diagnosed. In horses, 19 out of 23 submissions were neoplasms and most were sarcoid (8/23) and SCC (8/23). In sheep, all samples represented SCC of the eyelids (5) and third eyelid (1). For the second manuscript, cases of hyphema in dogs and cats submitted to necropsy were examined. Twenty cases, 14 dogs and six cats of several ages and breeds and of both sexes were included in the study. Hyphema presented as a unilateral (14 cases out of 20) or bilateral (6/20) disorder in dogs and cats and extension of hemorrhage varied from minimal to diffuse. Hyphema was secondary to systemic disease (15/20) or occurred as a primary ocular lesion (5/20) in four dogs and one cat. Primary hyphema was always unilateral. In four of these cases, the cause of hyphema was trauma and remaining case was caused by phacoclastic uveitis in a dog with bilateral hypermature cataract. Various causes of bleeding disorders were found related to secondary hyphema: in decreasing order of frequency, they included vasculitis (8/15), systemic hypertension (5/15), and acquired coagulopathies (2/15). / Esta tese envolveu o estudo de doenças oculares e perioculares de animais domésticos, e incluiu um artigo sobre lesões de patologia cirúrgica e um artigo sobre hifema em cães e gatos submetidos à necropsia. Para o primeiro trabalho, foram examinados 33.075 laudos de exames histopatológicos realizados num laboratório de diagnóstico de patologia veterinária na Região Central do Rio Grande do Sul durante 50 anos. Destes, 540 (1,6%) eram de lesões oculares e perioculares. Por várias razões, 90 espécimes foram excluídos do estudo, restando 450. Mais da metade dos casos correspondiam a espécimes de cães (53,5%), seguidos por bovinos (28,2%), gatos (11,1%), cavalos (5,1%), ovelhas (1,3%), coelhos (0,4%), e porco (0,2%). As pálpebras foram o local mais prevalente (248/450) de ocorrência das lesões em cada uma das espécies, seguidas da terceira pálpebra (73/450) e conjuntiva (27/450). Em cães, as lesões nas glândulas sebáceas consistiram nos achados mais comuns, seguidos dos tumores melanocíticos e de conjuntivites inespecíficas. Em bovinos, os locais anatômicos afetados por lesões perioculares e oculares, em ordem decrescente de frequência, foram pálpebra, córnea e terceira pálpebra. Somente o carcinoma de células escamosas (CCE) perfez 80,3% de todas as lesões diagnosticadas em bovinos. Em gatos, a maioria (39/50 casos) das lesões diagnosticadas era de neoplasia maligna, e CCE hemangiossarcoma e fibrosarcoma foram os diagnósticos mais frequentes. Em equinos 19 de 23 submissões eram neoplasmas e os mais comuns foram sarcoide (8/23) e CCE (8/23). Em ovinos, todas as amostras correspondiam a casos de CCE de pálpebra (5/6) ou terceira pálpebra (1/6). Para o segundo trabalho, casos de hifema em cães e gatos submetidos à necropsia foram examinados. Vintes casos, 14 cães e seis gatos de várias idades e raças e de ambos os sexos foram incluídos no estudo. O hifema teve uma apresentação unilateral (14 casos dos 20) ou bilateral (6/20), e a extensão da hemorragia variou de mínima a difusa. O hifema era secundário à doença sistêmica (15/20) ou ocorreu como lesão ocular primária em cinco dos 20 casos (quatro cães e um gato). O hifema primário foi sempre unilateral; a causa foi traumatismo em quatro desses casos, e o caso restante foi causado por uveíte facoclástica em um cão com catarata hipermadura bilateral. Várias causas de distúrbios hemorrágicos foram encontradas em relação ao hifema secundário: em ordem decrescente de frequência foram: vasculite (8/15), hipertensão sistêmica (5/15) e coagulopatias adquiridas (2/15).

Les maladies auto-immunes et systémiques sont des maladies sur lequel le champ de la recherche pose son œil de façon appuyée depuis 15 ans, du fait de l’émergence de thérapies biologiques ciblées. Ces pathologies sont volontiers hétérogènes, au mieux de fréquence ou caractéristiques particulières dans les populations d’origine Africaine. La connaissance de l’épidémiologie, et des caractéristiques de ces maladies est un préalable essentiel à la mise en place de recherche plus fondamentale pour aider à décomposer leurs physiopathologies souvent extrêmement complexes. En effet, la comparaison de différences marquées entre deux expressions dans des populations différentes d’une même maladie peut permettre d’aider à en dénouer le fil. Nous proposons dans ce travail une estimation des caractéristiques du lupus cutané et du lupus systémique en Guyane Française qui retrouve une faible fréquence de la maladie, la plus faible jamais retrouvée dans une population subsaharienne. Nous décrivons en Martinique sur le plan épidémiologique comme clinique une forme rare de myosite appelée syndrome des anti-synthétases semblant très particulière, l’épidémiologie et la description de la maladie de Kikuchi-Fujimoto pour la première fois dans la littérature, l’épidémiologie et les caractéristiques à base de population de la maladie de Behcet, des principales vascularites (périartérite noueuse, micropolyangéite, granulomatose éosinophile avec polyangéite, granulomatose avec polyangéite), de l’hypertension pulmonaire des connectivites qui semblent plus fréquentes que chez les Européens. Les néphropathies du lupus systémiques sont décrites dans la population Guadeloupéenne montrant une grande fréquence des néphropathies prolifératives. Le protocole EUROLUPUS qui permet le traitement de ces néphropathies prolifératives du lupus systémique avec de faibles doses de cyclophosphamide et de corticoïdes, est évalué en Martinique sur 30 patients alors qu’il ne l’a jamais été dans une population d’origine Africaine. Il semble y être aussi efficace que chez les patients d’origine Européenne, alors que les néphropathies y ont un pronostic meilleur. La maladie de Sjögren primaire est décrite en Martinique très proche de ce qu’on trouve en Europe sur le plan du tableau clinique et évolutif alors que cela n’est l’objet d’aucune étude dans une population d’origine noire Africaine. Nous avons par ailleurs montré en Martinique l’amélioration de la prise en charge du lupus systémique en Martinique au travers de la régression au fil du temps d’une des complications de la corticothérapie les plus pénibles pour les patients, l’ostéonécrose aseptique. La sclérodermie systémique est décrite à base de population avec épidémiologie dans les deux départements de Guadeloupe et Martinique, montrant des caractéristiques proches de celles retrouvées chez les AfroAméricains. Nous avons aussi montré la fréquence et la gravité des atteintes ORL des myopathies inflammatoires sur ces 2 départements avec une fréquence inhabituelle de certaines maladies auto-immunes dont le lupus systémique et les myosites inflammatoires associées aux anticorps anti-SRP, et l’absence de myosite à inclusion. Au total, nous apportons une somme de connaissance descriptive de ces maladies auto-immunes et systémiques permettant la mise en place de recherches plus fondamentales avec des bases solides par rapport aux profils hétérogènes de ces maladies. / Auto-immunes and systemic diseases are priorities for researchers since 15 years. This is related to the emergence of biological therapies, associated to great efficacy. Although, these diseases are heterogeneous, depending of different parameters such as ethnicity or geography. In the African descent population, we encounter unusual or particular manifestations of these diseases. Also, the knowledge of epidemiology and population based descriptions are crucial to properly initiate works on these populations, but also to understand a particularly complex physiopathology by using differences between populations. We describe in this work the population based characteristics of pure cutaneous lupus and systemic lupus, including an epidemiology of the incidence of the lowest incidence ever found in a population of African heritage. We also describe a population based series of anti-synthetase syndrome, confirming that the presentation is totally different compared to caucasians, and allows in Martinique the incidence, never explored before. We also provide the first evaluation of Kikuchi-Fujimoto disease in a population of African origin, and the first incidence ever realized. We do the same evaluation of the epidemiology of Behcet’s disease in a black origin population that shows that this disease was at a similar frequency in Martinique and in Europe. Micropolyangeitis, polyarteritis, eosinophilic granulomatosis with polyangeitis and Granulomatosis with polyangeitis were evaluated in an epidemiologic study in Martinique, with addition of some cases from other French American region for a more powerful characteristics description. These diseases seem less frequent than in Europe, associated with less severity except for micropolyangeitis. EUROLUPUS, a protocol with low dose IV cyclophosphamide and low dose steroids, used to treat proliferative nephritis of systemic lupus is shown to have the same efficacy in Martinique than in patients of European origin. Primary Sjögren syndrome, evaluated in Martinique, is very similar in expression than what is found in Europe. The decrease overtime of aseptic osteonecrosis, a steroid side effect, is a witness of better control of systemic lupus activity with less usage permitted by protocols and new immunosuppressive drugs such as mycophenolate. Systemic sclerosis is described as very close to African American in a population based study in Martinique and Guadeloupe. We finally show that the rare ENT involvement of idiopathic inflammatory myositis is frequent in our population, associated with poor outcome, and surprisingly frequently related to systemic lupus and necrotizing myositis associated to SRP antibody but not to inclusion body myositis. To conclude, we allow an amount of description of these diseases in our region, including pioneer studies. This works tends to be the basis for studies to be continued in a more fundamental way in our countries.

Les vascularites cryoglobulinémiques associées au virus de l'hépatite C (VC-VHC) sont caractérisées par une expansion clonale de lymphocytes B mémoires anergiques CD27+IgM+CD21-/low (Bm21-), un défaut quantitatif en lymphocytes T régulateurs (Tregs) et une polarisation Th1. Les antiviraux d'action directe sans interferon (DAAs) sont très efficaces chez les patients VC-VHC mais leur mécanisme d'action sur l'immunité cellulaire reste inconnu. Nous montrons que les DAAs normalisent la plupart des perturbations de l'homéostasie lymphocytaire B et T, en diminuant l'expansion des Bm21- et T folliculaires, et en augmentant les T régulateurs (Tregs). Nous avons étudié l'effet des Bm21- sur les sous-populations lymphocytaires T, et les réactivités de leur récepteur B. Nous montrons que les Bm21- stimulés par le CpG favorisent la sécrétion d'IFNγ par les T effecteurs et induisent leur prolifération. Inversement, les Bm21- stimulés par CpG diminuent la capacité proliférative des Tregs. Nous montrons la diversité intraclonale des IgM mutés des Bm21-, conduite par maturation d'affinité antigène dépendante. Les anticorps (Ac) des Bm21- ont une activité facteur rhumatoïde (FR) mais ne sont ni polyréactifs, ni autoréactifs contre les autoantigènes ubiquitaires. Les Ac des Bm21- ne présentent pas de réactivité croisée contre des antigènes viraux du VHC. Les Bm21- stimulés par CpG ont une signature transcriptomique révélant un phénotype non tolérogène. Ainsi, ces résultats suggèrent le rôle majeur des Bm21- dans le défaut tolérance des patients CV-VHC, à la fois par la stimulation CpG conduisant à une réactivation des Bm21- anergiques, et par l'expression clonale des IgM à activité FR. / Hepatitis C virus-associated cryoglobulinemia vasculitis (HCV-CV) is characterized by an abnormal clonal expansion of anergic CD27+IgM+CD21-/low memory B cell (Bm21-), a quantitative defect in regulatory T cells (Tregs) and Th1 profile. Interferon-free direct-acting antivirals (DAAs) proved to be very effective in patients with HCV-CV but their mechanisms of action and their effects on cellular immunity remain poorly defined. Our results indicate that DAAs effectively normalizes many of the disturbances in peripheral B- and T-lymphocyte homeostasis of HCV-CV patients, by reducting Bm21- and T follicular helper expansion and promoting Tregs. Then, we investigated the effects of Bm21- on T-cell subpopulations and study the reactivities of their B-cell receptors. We show that CpG-stimulated Bm21- promote the secretion of IFNγ by effector T cells and induce their proliferation. Conversely, stimulated Bm21- reduce the proliferative capacity of regulatory T cells. Bm21- B-cell expansions show intraclonal diversity of highly mutated IgM antibodies that were shape by an antigen-driven maturation process. Bm21- antibodies possess rheumatoid factor activity but are neither polyreactive nor recognize ubiquitous autoantigens. No crossreactivity of Bm21- antibodies against several HCV antigens was observed. We also identify a transcriptional signature in CpG-stimulated Bm21- revealing a phenotype sufficient to break the immune tolerance. Thus, these results strongly suggest a major role for Bm21- in defective tolerance of HCV-CV patients, both through CpG stimulation leading to reactivation of anergic Bm21-, and through the clonal expression of IgM antibodies with RF activity.

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