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BackgroundIdentifying reliable biomarkers of response to biologics in rheumatoid arthritis (RA) is necessary to improve responsiveness, preserve functions and structure of joints, as well as to reduce treatment’s cost. Single nucleotide polymorphisms (SNP’s) of Fc-gamma receptors genes (FCGRs), by inducing a variation of receptors’ affinity to Fc fragment of Gamma immunoglobulin, might influence the efficacy of therapeutic monoclonal antibodies by modifying their clearance.ObjectivesThe aim of this study was to investigate whether FCGR2A, FCGR3A and FCGR3B SNP’s were predictive factors of response to rituximab (RTX) in Tunisian RA patients.MethodsA cross-sectional, observational and analytic multicentric cohort study was conducted in a group of patients suffering from RA treated with RTX. Treatment outcome was evaluated after 6 months, using DAS28 variation from baseline and EULAR response criteria. R131H-FCGR2A, F158V-FCGR3A and NA1/NA2-FCGR3B SNPs were studied using PCR-SSP and direct sequencing process.ResultsThirty-four patients were enrolled with a sexe ratio M/F=5/29. The mean age at inclusion was 54,24±11,78 years [29-77]. All patients received at least one cs-DMARDS priorly to the prescription of RTX. Concomitant treatment with methotrexate was pursued in 77,3% of patients. As shown in Table 1, an association, that tend to signification, was found between R/R FCGR2A receptors and a greater variation in DAS28 score (p=0,053). This association was also found using EULAR criteria, since all patients with R/R genotypes had a good or moderate response to RTX but was not significative (p=0,131).Table 1.Correlation of FCGR SNPs with response to rituximab at 6 months of treatmentGenetic studyΔDAS28CRPpΔDAS28ESRpEULAR (R-) (n=7)EULAR (R+) (n=27)PFCGR2A R131H*0,1380,7610,301GenotypesRR2,53±1,560,0531,83±0,750,4800(0)7 (100)0,131HH2,05±2,510,8682,29±1,640,6831 (33,3)2 (66,7)0,576RH1,09±1,360,062,00±1,730,8556 (25)18(75)0,324AllelesR1,45±1,520,8681,96±1,490,6836 (0,194)25(0,806)0,576H1,17±1,430,0532,1±1,600,4807 (0,259)20(0,741)0,131FCGR3A F158V*0,4280,8730,370GenotypesFF1,35±1,570,8601,91±1,860,7052 (16,7)10(83,3)0,676VV0,95±0,980,2882,85±0,320,6371 (10)9(90)0,324FV2,06±1,830,2371,84±1,5114 (33,3)8(66,7)0,175AllelesF1,72±1,700,2881,87±1,560,6376 (0,25)18(0,75)0,324V1,56±1,570,8602,13±1,330,7055(0,227)17(0,773)0,676FCGR3B NA1/NA2*0,2170,4850,645GenotypesNA1NA12,29±1,810,092,13±1,080,7152(22,2)7 (78,8)0,888NA2NA20,79±1,300,3290,60,3432 (33,3)4 (66,7)0,395NA1NA21,23±1,360,3912,28±2,070,3453 (15,8)16(84,2)0,436AllelesNA21,15±1,330,091,95±1,950,7155 (0,20)20(0,80)0,888NA11,60±1,580,3292,19±1,450,3435 (0,179)23(0,821)0,395DAS: disease activity score,ΔDAS: mean variation of DAS at 6 months, *:Comparison of the global distribution of the 3 genotypes,**: p while comparing the prevalence of R/R genotype to R/H and H/H genotypes,R+: good or moderate EULAR response,R-: bad EULAR responseConclusionThe low affinity receptor R/R FcgRIIa might be predictive of good response in RA patients treated with RTX. More studies need to be conducted in larger cohorts to confirm this association, with the aim of identifying reliable biomarkers of response to biologics to improve responsiveness, preserve joints functions and structure, as well as reduce treatment’s cost.Disclosure of InterestsNone declared

ResumeObjectif Evaluer le taux d’immunisation anti-erythrocytaire et anti-HLA dans les hemoglobinopathies. Patients et methodes Etude transversale (octobre 2009–mars 2010) concernant 83 patients suivis pour hemoglobinopathie. La recherche d’anticorps irreguliers est realisee par deux techniques : Coombs indirect et technique enzymatique sur carte gel. La recherche des anticorps anti-HLA de classe I est faite par la technique de lymphocytotoxicite complement dependante. Resultats L’âge moyen est de 30 ans (14–64 ans), le sex-ratio M/F est de 0,84. Il s’agit de 42 cas de syndromes drepanocytaires majeurs (29 drepanocytoses homozygotes et 13 drepano-thalassemies) et de 41 cas de syndromes thalassemiques (26 thalassemies majeures et 15 intermediaires). La frequence d’allo-immunisation anti-erythrocytaire est de 22,89 % sans difference entre les syndromes drepanocytaires et thalassemiques (7,31 %). La frequence d’auto-immunisation anti-erythrocytaire est de 24,8 %. Elle est plus elevee dans les syndromes thalassemiques (41,46 %) que dans les syndromes drepanocytaires (7,14 %) (p

Introduction It has been recently suggested that microparticles (MP) play a role in the pathogenesis of thrombotic complications. This study aimed to assess the contribution of procoagulant activity expressed by circulating MP in thrombotic events in MPN patients. Methods Seventy-four MPN patients were enrolled in a trans-sectional study. The MP procoagulant activity was measured using two assays: (i) the thrombin generation (TG) assay used in different conditions with the addition of both tissue factor (TF) and phospholipids (PL) and with the addition of TF or PL alone and (ii) the PROCOAG-PPL assay. Results The mean age was 62 (26 men and 48 women). The prevalence of thrombotic events was 28%. When comparing patients with thrombosis to those without, age, sex, MPN type, cardiovascular risk factors, and history of thrombosis were not significantly associated with thrombosis. The JAK2 V617F mutation was significantly associated with thrombotic events (90% vs 67%; P=.04). Results from the TG assay and the PROCOAG-PPL assays did not demonstrate a significant association between the MP procoagulant activity and thrombotic events. Conclusion The MP procoagulant activity did not predict thrombosis in MPN patients. The contribution of TG assay in the assessment of the thrombotic risk is still in debate.

Resume L'hepatite virale B constitue un probleme majeur de sante publique dans le monde. Le virus responsable se caracterise par sa variabilite genetique. La recherche de l'antigene de surface (Ag HBs) est utilisee pour la detection du virus, mais ne prejuge pas de la presence d'une replication virale. La detection de l'ADN viral par la reaction de polymerisation en chaine (PCR) a represente un important progres technique permettant de mettre en evidence la presence de l'acide nucleique viral dans le serum des sujets infectes par le virus de l'hepatite B (VHB) meme lorsque celui-ci est en tres faible quantite. La PCR appliquee au diagnostic de l'infection par le VHB pose un probleme de reproductibilite et de sensibilite et presente des difficultes dans l'interpretation des resultats. Dans cette etude, nous avons analyse les resultats obtenus par la technique PCR en utilisant 13 amorces specifiques et des amorces consensus correspondant a differentes regions du genome viral dans le but d'evaluer la specificite et la sensibilite de la PCR selon le couple d'amorces utilise. Des resultats satisfaisants sont obtenus avec les amorces qui amplifient les regions pre-S et X ainsi qu'avec les amorces consensus dans une PCR nichee utilisant le couple Xa/Xb et le couple HBx1/HBx2. Ces resultats indiquent que la recherche de l'ADN du VHB par PCR, est une technique sensible et specifique pour detecter la presence de virus dans le serum des patients. Elle peut donc etre appliquee en routine pour le diagnostic de l'infection par le VHB en utilisant les amorces appropriees avec un cout relativement faible compare aux kits commerciaux.

Congenital heart block (CHB) associated with maternal anti-SSA/SSB antibodies: a report of four cases. CHB detected in utero is strongly associated with maternal antibodies to SSA (Ro) and SSB (La). Their pathogenic role in the development of CHB has been established in several studies. The mothers of affected infants frequently had autoimmune disease (systemic lupus erythematosus, Sjogren's syndrome) or were entirely asymptomatic. It is very difficult to identify pregnant asymptomatic mothers carrying anti-SSA/SSB antibodies. We report four cases of infants born to asymptomatic mothers with anti-SSA/SSB antibodies, three of them developed isolated congenital cardiac heart block and one with no evidence of CHB. All three CHB are detected during pregnancy between 16 and 24 weeks of gestation. All maternal sera contained antibodies to SSA alone or the both SSA and SSB. Three of four subsequent pregnancies were complicated by heart block. One child affected died in utero. While the two other newborns with CHB required pacemaker insertion during the first 3 months of life. Although the association of anti-SSA/SSB with CHB is widely accepted, the precise mechanism by which these antibodies cause cardiac conduction abnormalities remains to be defined. Antibodies to SSA/SSB have been proposed to be a serologic marker for neonatal lupus syndrome and CHB. Fetal and neonatal diseases are presumed to be due to the transplacental passage of these IgG autoantibodies from the mother into the fetal circulation. Since these antibodies may have a pathogenic role in CHB, screening of infants with isolated CHB or neonatal lupus and their mothers for the presence of anti-SSA and anti-SSB is strongly recommended.

Introduction L’infliximab est un anticorps monoclonal chimerique (humain–murin) qui a montre des effets therapeutiques spectaculaires chez les patients atteints de rhumatisme inflammatoire chronique (RIC), bien que l’efficacite de cet agent peut diminuer. L’un des principaux facteurs responsables de cette attenuation est attribue au developpement d’anticorps anti-medicamenteux (ADA). Le but de ce travail est de rechercher la prevalence des ADA anti-infliximab dans les RIC. Materiels et methodes Etude descriptive transversale et multicentrique chez 40 patients suivis pour spondylarthrite (SPA) ou pour polyarthrite rhumatoide (PR) mis depuis au moins 6 mois sous infliximab (INF) ayant eu un prelevement sanguin le jour de la perfusion avec recherche d’ADA et un dosage serique de l’INF circulant realises avec un test ELISA avec evaluation des scores d’activite DAS28 et BASDAI le jour de l’inclusion. Resultats Notre cohorte comprend 21 SPA (16 H/5F) et 19 PR (2 H/17 F) d’âge moyen de 43 ans pour la SPA et 53 ans pour la PR. La PR etait seropositive dans 78,94 %. La dose par perfusion d’INF etait de 3 mg/kg pour 3 SPA/15 PR et de 5 mg/kg pour 18 SPA/4 PR. Un traitement de fond par DMARD etait associe ; methotrexate dans 5 SPA/15 PR ou salazopyrine dans un cas de SPA ou azathioprine dans 1 SPA/1 PR ou association salazopyrine et azathioprine dans un cas de SPA. Les scores d’activite BASDAI pour la SPA etait en moyenne de 5,08 avant l’INF. Apres l’inclusion 8 cas avaient un BASDAI ≥ 4. Pour la PR, le DAS28 etait en moyenne de 6,2 avant INF. La reponse EULAR etait moderee dans 4 cas et mauvaise dans 11 cas. La recherche d’ADA etait positive dans 50 % des cas avec un taux serique circulant d’INF indetectable, soit 12 cas/21 pour la SPA contre 8 cas/19 pour la PR sans difference entre les 2 groupes. La presence d’ADA etait inversement correlee au dosage serique du biomedicament pour la PR (p = 0,027) et pour la SPA (p = 0,005). Conclusion L’immunogenicite sous infliximab s’avere importante et donc probablement avec un risque d’echec plus important d’ou l’interet de rechercher ces ADA. Mais l’immunogenicite n’est pas le seul facteur qui influence la reponse therapeutique.

Evaluate the anti-erythrocyte and anti-HLA immunization rates in hemoglobinopathies.Cross-sectional study (October 2009-March 2010) on 83 patients followed for hemoglobinopathies. The irregular antibodies research is realized by two techniques: indirect Coombs and enzymatic technique on gel cards. The search for anti-HLA class I antibodies is done by complement dependent lymphocytotoxicity.The mean age was 30 years (14-64 years), the sex ratio M/F is 0.84. Our series included 42 cases of sickle cell disease (29 homozygous sickle cell anemia and 13 sickle-thalassemia) and 41 cases of thalassemia syndromes (26 major and 15 intermediate). The anti-erythrocyte alloimmunization rate is 10.84% without difference between thalassemia syndromes and sickle cell disease. The autoimmunization rate (22.89%) is higher in thalassemia syndromes (41.46%) than in the sickle cell disease (7.14%) (P0.001). The anti-HLA immunization rate is 31.6% without difference between thalassemia syndromes and sickle cell disease. The young age, transfusion at a young age and the total number of transfusions are the factors that increase the risk of anti-erythrocyte autoimmunization. No clinicobiological parameter does influence the anti-erythrocyte and anti-HLA alloimmunization. There is no significant association between anti-erythrocyte and anti-HLA immunization.The erythrocyte and anti-HLA anti-immunization rates are high in our series. Preventive strategy is needed to ensure optimal blood safety.

Immunoblotting and ELISA methods are now employed for the detection of anti Ro/SSA and anti La/SSB antibodies sometimes more often than double immunodiffusion or counter-immunoelectrophoresis. We have developed an immunoblotting technique for the detection of anti Ro/SSA and anti-La/SSB antibodies. This assay named IB-Hela, which uses a Hela cell extract, was compared with the double immunodiffusion technique like two other commercial immunoassays (Elisa test from Sanofi-diagnostic Pasteur and Line immunoassay from Innogenetics). This evaluation shows a good agreement especially in the case of Ro/SSA antibodies detection. IB-Hela seems to be useful in the La/SSB detection with a better sensitivity than the double immunodiffusion technique. We conclude that the IB Hela is helpful for the search for anti-Ro/SSA and anti-La/SSB autoantibodies and that it can be used as an alternative method to the classical techniques of immunodiffusion and counter immunoelectrophoresis.

Acquired protein S (PS) deficiency in systemic lupus erythematosus (SLE) has been previously reported, but its mechanism and its possible thrombotic role have not been established. The aim of our study was to provide further evidence for auto-immune PS deficiency in 27 Tunisian SLE patients, using PS-specific enzyme-linked immunosorbent assay (ELISA) and surface plasmon resonance technology (SPR). PS deficiencies for PS activity, free PS or total PS, respectively, were found in 19, 18 and 12 patients. A significant correlation (r= -0.475, P< 0.016) was found between free/total PS ratio and C4bBP levels, suggesting a role of inflammation in free PS deficiency. Immunoglobulin IgG antibodies to PS were detected in four patients by both ELISA and SPR, in six patients only by ELISA, and in two patients only by SPR. Signals for anti-PS IgG by ELISA and SPR were, however, significantly correlated (r = 0.549, P = 0.003). These results suggest that an auto-immune mechanism could account for low PS activity in patients with SLE. Auto-antibodies to PS may form immune complexes, inducing increased clearance of PS or interfering with the protein C-protein S system.

Fifty-eight patients on maintenance hemodialysis in a dialysis unit at Tunis, Tunisia were tested for anti-hepatitis C virus (anti-HCV) antibodies by second generation ELISA test, and for HCV-RNA by nested reverse transcriptase polymerase chain reaction (RT-PCR) of 5′ non-coding region. Specificity of the antibodies was confirmed by immunoblot test. HCV genotype was defined using INNO-LIPA test. Twenty-seven out of 58 patients (46.5%) were reactive by ELISA. Transaminase levels were assessed over a six-month period and showed normal average values. Fourteen of the 27 anti-HCV positive patients (51%) were positive by RT-PCR. Type 1b HCV genotype was the most prevalent, seen in all the dialysis patients and one patient in addition, was co-infected with genotype 4. There was a significant correlation between the duration on dialysis (over five years) and the prevalence of anti-HCV-positive patients (P< 0.005) while no correlation existed between the number of blood transfusions and the presence of anti-HCV antibodies. The present study illustrates the high prevalence of HCV infection among Tunisian dialysis patients (51%) and indicates that the spread may be nosocomial rather than transfusion-related.

Chronic viral hepatitis C is often associated with various autoimmune disorders. We report two patients infected by genotype 1b hepatitis C virus associated with primary biliary cirrhosis. These patients had anicteric cholestasis associated with cytolysis and positivity of M2 antimitochondrial antibodies at a titre of 1/200. Liver biopsy revealed chronic hepatitis in one case and histological pattern of primary biliary cirrhosis in the other. One patient was treated by antiviral therapy; the other only by ursodesoxycholic acid because of the association with hemolytic anemia. Association between primary biliary cirrhosis and chronic viral hepatitis C is uncommon and associated with diagnostic and therapeutic challenges.

To investigate the relationship between the soluble HLA-G (sHLA-G) and the appearance of acute renal rejection (AR) episodes we have quantify in this study the level of sHLA-G by enzyme-linked immunosotrbent assay in 42 kidney transplant patients classified in two groups: G1: 17patients with acute rejection (AR+) and G2: 25 patients without AR (AR-). To establish our normal sHLA-G ranges, serum samples from 18 healthy controls were tested. Pre-transplantation sHLA-G levels were significantly increased in patients (mean +/- standard error of the mean, 60.48 +/- 12.18 units/ml) than healthy subjects (19.11 +/- 4.9 units/ml) (p = 0.001). Although the difference was not statistically significant, G1 patients (AR+) revealed lower levels of sHLA-G (mean +/- standard error of the mean, 31.25 +/- 6.71 units/ml) compared to G2 patients (AR-) (53.43 +/- 1721 units/ml). Nevertheless, the course of total sHLA-G levels was nearly identical in patients with and without rejection. Nonparametric analysis revealed that pre-transplantation levels of sHLA-G18.00 units/ ml (sensitivity: 87.8% and specificity of 72.2%) were not related to rejection. Also, multivariate analysis regarding anti-HLA antibody status, recipient age and gender showed that sHLA-G could not be an independent risk factor for renal graft rejection. However, a higher sera levels of sHLA-G seemed to contribute to better kidney allograft survival rate after 10 years of follow-up (significance tendency: p = 0.091) as shown by the survival analysis. Because of the small number of subjects studied, these results must be treated with caution. A much larger cohort of kidney transplant patients according to acute rejection would seem necessary to confirm these findings.

Introduction La cholangite biliaire primitive anciennement appelee cirrhose biliaire primitive (CBP), est une pathologie cholestatique du foie survenant sur un terrain auto-immun. Le syndrome de Gougerot-Sjogren (SGJ) est associe a la CBP dans 21 a 81 % des cas. But Determiner la frequence de survenue du SGJ au sein d’une serie tunisienne de patients atteints de CBP et de determiner les caracteristiques epidemiologiques, cliniques et therapeutiques du sous-groupe CBP-SGJ. Patients et methodes Etude retrospective, menee dans une unite tunisienne d’hepato-gastro-enterologie, etendue sur 5 ans, colligeant tous les patients suivis pour une CBP. Resultats Trente-neuf patients ont ete inclus durant la periode d’etude, representes par 7 hommes et 32 femmes. L’âge moyen des patients etait de 58 ans ± 10. Des maladies auto-immunes associees etaient observees chez 4 patients : 3 cas de diabete insulino-dependant et 1 cas de thyroidite. Les deux tiers des patients etait symptomatiques (prurit dans 46,1 % des cas, asthenie dans 58,9 % et ictere dans 53,8 % des cas). Environ la moitie des patients (41 %) etait cirrhotiques. Le SGJ etait observe chez 26 % des cas. Dans le sous-groupe CBP-SGJ, l’âge moyen etait 51,7 ans ± 9,75 avec un sex-ratio 9F/1H. Les symptomes relatifs a la CBP etaient presents dans 90 % des cas. Vingt pour cent de ces malades etait cirrhotique et 10 % presentait des complications liees a la cirrhose. Tous les patients etaient traites par l’acide ursodesoxycholique (15 mg/kg/j). Une reponse optimale sous traitement etait observee dans 80 % des cas. La presence d’un SGJ n’etait pas correlee de facon statistiquement positive a une forme symptomatique, a une fonction hepatique evoluee, a la survenue des complications de la cirrhose ou a la reponse au traitement par AUDC. Conclusion Dans notre serie, le quart des patients presentait un SGJ secondaire a la CBP soulignant la nature systemique des maladies auto-immunes et rejoignant ainsi les donnees de la litterature. Cette coexistence ne semble pas, par ailleurs, modifier le profil clinique et evolutif de la CBP.

Introduction La pancreatite auto-immune (PCAI) est une forme particuliere et rare de la pancreatite chronique (moins de 5 % des cas) qui a ete recemment individualisee. But Preciser les caracteristiques cliniques, biologiques, morphologiques et therapeutiques de la PCAI, a travers les observations de 3 malades suivis dans une unite tunisienne d’hepato-gastro-enterologie. Observation 1 : Il s’agit d’un homme âge de 45 ans, qui consulte pour des epigastralgies transfixiantes. La biologie montrait une cholestase anicterique (des GGT a 1,5 fois la normale (N) et des PAL a 3 N). La lipasemie etait normale. L’echographie abdominale montrait une dilatation des voies biliaires intra et extra hepatiques (VBIEH). Le complement par une bili-IRM montrait un aspect de pancreatite auto-immune pseudo-tumorale avec une stenose monoliforme du canal pancreatique principal. Les IgG4 etaient eleves. Le patient a ete traite par une corticotherapie pendant 5 mois. L’evolution etait favorable avec une disparition des epigastralgies, une regression de la cholestase (GGT normales et PAL 1,2 N). La bili-IRM de controle a montre une regression de la tumefaction pancreatique et de la stenose monoliforme. Observation 2 : Il s’agit d’un homme âge de 65 ans, presentant un diabete insulino-dependant qui consultait pour des douleurs abdominales aigues avec une cholestase biologique anicterique (GGT 14 N et PAL N). La lipasemie etait normale. L’echographie abdominale montrait une vesicule biliaire a paroi epaissie a contenu lithiasique avec une dilatation des VBIEH. La bili-IRM montrait un aspect de pancreatite auto-immune pseudo-tumorale associe a une cholangite. Le dosage des IgG4 etait normal. Le patient a ete traite par une corticotherapie pendant 6 mois avec persistance d’une cholestase anicterique (GGT 11 N) et du meme aspect radiologique a la bili-IRM de controle indiquant une nouvelle cure de corticotherapie associee a des immunosuppresseurs et l’acide urso-desoxycholique. Observation 3 : Il s’agit d’un homme âge de 20 ans consulte pour des epigastralgies transfixiantes en rapport avec une pancreatite aigue (lipasemie a 3 N). La TDM abdominale faite a 48 heures a montre un pancreas tumefie heterogene et le complement d’exploration par une bili-IRM a montre un pancreas pseudo-tumoral. Le dosage des IgG4 etait normal. Le patient a ete mis sous corticotherapie forte dose avec une bonne evolution clinico-biologique et morphologique. Conclusion La PCAI doit etre systematiquement evoquee devant toute formation tumorale pancreatique, dans un contexte epidemiologique, clinique, serologique et radiologique ne cadrant pas completement avec un adenocarcinome pancreatique. Il importe donc, malgre sa rarete, de reconnaitre ce diagnostic etant donne sa sensibilite caracteristique a la corticotherapie.

Introduction: Our aim was to investigate the possibility of a significant relationship between chemokines and chemokine receptor genes polymorphisms and the spontaneous clearance or the persistence of HCV infection. Methods: A total of 96 hemodialysis (HD) patients infected with HCV were classified into two groups: G1 included 73 patients with persistently positive HCV-RNA and G2 included 23 HD patients who have spontaneously eliminated the virus. The control group consisted of 170 healthy blood donors. All subjects were genotyped for CCR5 Δ32, CCR5 (-59029) A/G, CCR2 (64Ile) and MCP-1(-2518) A/G gene polymorphisms. Results: Our results showed statistically significant increased frequencies of the CCR2 (64Ile) and the (-59029) CCR5 A alleles in patients infected with HCV (22.1% and 35.9%) compared to G1 (24.3% and 40.6%) and compared to controls (14.4% and 20%). We also observed a lower frequency of the MCP-1 G allele and a greater frequency of the CCR5Δ32 variant in G2 (15.2% and 6.5%) compared to G1 (22.6% and 1.4%) that was not statistically significant. However, adjustment for known covariates (age, gender and HCV genotypes) didn’t confirm the results of univariate analysis. Conclusion: In conclusion, our study suggests a possible role for some of the studied chemokines polymorphisms in the spontaneous clearance or persistence of HCV infection in Tunisian population. These results should be further investigated by a prospective cohort studies and large population-based studies.Keywords: Chemokines; Receptors; Hepatitis C virus; Spontaneous Clearance; Polymorphisms.

Resume Au cours de cette etude, nous avons analyse les donnees clinico-biologiques relatives a 16 enfants suivis dans des hopitaux de Tunis et chez qui un lupus a ete diagnostique avant l'âge de 15 ans. Sur cette courte serie, il s'est avere qu'une atteinte renale etait presente dans 75% des cas et les biopsies renales, la ou elles ont pu etre pratiquees, ont souvent revele des aspects histologiques severes. Tous les patients qui ont pu etre suivis ont recu une corticotherapie parfois additionnee en cas de mauvaise reponse, d'une therapeutique immunosuppressive. Cinq patients sont decedes dans un contexte de defaillance renale consecutive a une nephropathie severe. Cette etude du lupus pediatrique en Tunisie confirme la severite de la maladie lorsqu'elle survient chez l'enfant.

The hepatitis C virus (HCV) is the principal agent of viral chronic hepatitis. Cirrhosis and hepatocellular carcinoma are the major complications of this chronic infection. In haemodialysis, HCV infection remains a very frequent problem. Several autoimmune phenomena have been described during this infection. Two hundred haemodialysis patients, all of them anti-HCV (+), were included in this study to evaluate the frequency of Anti-Nuclear Autoantibodies (ANA), anti-cardiolipine antibodies (ACL), anti-smooth muscle antibodies (ASMA), anti-mitochondria antibodies (AMA), anti-thyroperoxydase antibodies (ATPO) and Rheumatoid Factor (RF) comparing them to healthy controls. Sixty eight serums (34%) patients were positive to at least one of the auto-antibodies tested. The difference between patients and controls was statistically significant. These markers were dominated by RF of the IgM isotype and ACL of the IgG isotype. Nevertheless, the positivity of ANA, ASMA, AMA and ATPO was not statistically different comparing to the controls. In addition, an association between the presence of the auto-antibodies and the viral replication was found suggesting that HCV is responsible for inducing these autoimmune phenomena.

The polymorphism of C4A and C4B genes was investigated in Tunisian patients with insulin dependent diabetes (IDDM) and compared to family members (sibs) and to healthy controls. Multiplex families were analysed. A significant increase in C4AQO (26.86% vs 6.90%) and C4BQO (40.29% vs 8.28%) phenotypes was noted in IDDM patients compared with controls. Using RFLP analysis, we confirmed the high frequency of C4 null alleles. We also observed that most of these alleles were genes deleted in IDDM patients (72.23% vs 20% for CA4QO and 74.07% vs 16.70% for C4BQO). A significant decrease in the C4B long (14.92% vs 67.12%) form of the gene was also demonstrated by RFLP analysis compared with controls. Two haplotypes were frequently associated with IDDM patients in whom the C4A and C4B were deleted genes.

Chronic viral hepatitis C is often associated with various autoimmune disorders. We report two patients infected by genotype 1b hepatitis C virus associated with primary biliary cirrhosis. These patients had anicteric cholestasis associated with cytolysis and positivity of M2 antimitochondrial antibodies at a titre of 1/200. Liver biopsy revealed chronic hepatitis in one case and histological pattern of primary biliary cirrhosis in the other. One patient was treated by antiviral therapy; the other only by ursodesoxycholic acid because of the association with hemolytic anemia. Association between primary biliary cirrhosis and chronic viral hepatitis C is uncommon and associated with diagnostic and therapeutic challenges.

Congenital heart block (CHB) associated with maternal anti-SSA/SSB antibodies: a report of four cases. CHB detected in utero is strongly associated with maternal antibodies to SSA (Ro) and SSB (La). Their pathogenic role in the development of CHB has been established in several studies. The mothers of affected infants frequently had autoimmune disease (systemic lupus erythematosus, Sjögren's syndrome) or were entirely asymptomatic. It is very difficult to identify pregnant asymptomatic mothers carrying anti-SSA/SSB antibodies. We report four cases of infants born to asymptomatic mothers with anti-SSA/SSB antibodies, three of them developed isolated congenital cardiac heart block and one with no evidence of CHB. All three CHB are detected during pregnancy between 16 and 24 weeks of gestation. All maternal sera contained antibodies to SSA alone or the both SSA and SSB. Three of four subsequent pregnancies were complicated by heart block. One child affected died in utero. While the two other newborns with CHB required pacemaker insertion during the first 3 months of life. Although the association of anti-SSA/SSB with CHB is widely accepted, the precise mechanism by which these antibodies cause cardiac conduction abnormalities remains to be defined. Antibodies to SSA/SSB have been proposed to be a serologic marker for neonatal lupus syndrome and CHB. Fetal and neonatal diseases are presumed to be due to the transplacental passage of these IgG autoantibodies from the mother into the fetal circulation. Since these antibodies may have a pathogenic role in CHB, screening of infants with isolated CHB or neonatal lupus and their mothers for the presence of anti-SSA and anti-SSB is strongly recommended.

Cryoglobulins are immunoglobulins which reversibly precipitate at cold temperatures. They are usually accompanied with polymorphic clinical manifestations and biological abnormalities. Cryoglobulins are associated with various clinical disorders which include autoimmune diseases, lymphoproliferative and infectious disorders. Because of their low concentration, detection and quantitation of cryoglobulins need very rigorous conditions when collecting blood from patients.

Immunoblotting and ELISA methods are now employed for the detection of anti Ro/SSA and anti La/SSB antibodies sometimes more often than double immunodiffusion or counter-immunoelectrophoresis. We have developed an immunoblotting technique for the detection of anti Ro/SSA and anti-La/SSB antibodies. This assay named IB-Hela, which uses a Hela cell extract, was compared with the double immunodiffusion technique like two other commercial immunoassays (Elisa test from Sanofi-diagnostic Pasteur and Line immunoassay from Innogenetics). This evaluation shows a good agreement especially in the case of Ro/SSA antibodies detection. IB-Hela seems to be useful in the La/SSB detection with a better sensitivity than the double immunodiffusion technique. We conclude that the IB Hela is helpful for the search for anti-Ro/SSA and anti-La/SSB autoantibodies and that it can be used as an alternative method to the classical techniques of immunodiffusion and counter immunoelectrophoresis.

We report the case of a young Tunisian woman hospitalised for reasons of general ill health. A immunological check-up revealed autoimmune disturbances and in particular anti-ribosomal P antibodies. We discuss the possible relation of these antibodies to the hepatitis C infection from which the patient was also suffering.

We searched for antibodies to hepatitis C in a sample of 3079 Tunisians in the suburban area of Tunis. 30 people were positive by ELISA and 22 were confirmed by immunoblotting. This result represents a prevalence of 0.71% which is close to the values reported in European countries of the Mediterranean area.

Antiphospholipids antibodies (AAP) were investigated in plasma of 62 patients with systemic lupus erythematosus, and studied for the possible interference of the excess in factor VIIIc-Von Willebrand factor (VWF-VIIIc) complex in the detection of lupus anticoagulants (LA) by the activated partial thromboplastin time (APTT). We used four commercial reagents and noted that each one exhibited a different level of sensitivity of LA; the most sensitive one allowed the detection of 16 LA positive plasmas while the less sensitive reagent detected only 6 positives. The Elisa test for IgG and IgM AAP detection was positive in 25 out of 62 plasmas (40%). Comparison of the Von Willebrand factor antigen level and the APTT values showed a significant negative corrélation with 2 reagents (r = 0.369, p0.01 and r = 0.272, p0.05 respectively) that were also the less sensitive to LA. The interference of an excess in VWF-VIIIc complex was further studied by the addition of purified factor VIII in 3 LA positive plasmas. Our results suggests that an excess of factor VIIIc could lead to false negative LA, using certain APTT reagents. We conclude that a more accurate LA detection require: sensitive reagents, a pool of normal plasmas selected with normal factor VIII level, as well as repeated testing of blood sampling withdrawn away of an inflammatory process to avoid false negative LA detection.

The anticardiolipin antibodies (aCL) are acquired inhibiting antibodies of the coagulation process. They interfere with the anionic phospholipids of the cellular membranous. These are frequently associated to the autoimmune diseases, especially the systemic lupus erythematosus (SLE), they expose the patient to thrombotic complications. In order to define the possible and prognostic predictive value of these aCL, a sequential research of these antibodies was performed on 12 patients suffering from SLE since 2 to 11 years. An average of one sample per year was drawn, either during an attack or in a routine control check. The detection of these IgG aCL did not appear to be related with be course of the disease. In fact, 3 of our patients, ill since respectively 2, 7 and 11 years, never showed any aCL. These aCL were positive during an attack in 80% of the cases. This positivity was associated to vascular thrombosis (2 cases), and cutaneous vascularity (6 cases) and, in one case, the presence of aCL was linked to inutero fetal death due to retruplacentary hematoma. This study confirms the association between aCL and thrombosis during systemic lupus erythematosus.

In this study, we have analyzed the clinical and serological features related to 16 Tunisian children in whom diagnosis of systemic lupus erythematosus was made before or at the age of 15. Renal involvement was found in 75% of cases and renal biopsies have mostly revealed severe histologic patterns. All of the patients who have been followed received corticosteroids and in some cases required additional cytotoxic drugs in order to control disease activity. Five children died in a context of a renal failure. This study of childhood lupus in Tunisia confirms that the clinical course of this disease in children is often aggressive.

The evolution of immunological parameters in mediterranean visceral leishmaniasis reveal a type III mixed cryoglobulin with rhumatoid factor activity and antileishmania antibodies. This cryoglobulin follows the clinical signs of the disease and disappear under treatment. The authors insist on the transitory character of this cryoglobulin which is in relation with polyclonal stimulation of the immune system by parasitical infection.

The presence of hepatitis B virus DNA, delta antigen and anti-delta antibodies was examined in 159 Tunisian chronic HBs Ag carriers: 45 were asymptomatic and 114 suffered from cirrhosis. Serum hepatitis B virus DNA was detected in two (4.5%) asymptomatic HBs Ag carriers and in 11 (10%) HBs Ag positive cirrhosis patients. The prevalence of HDV infection determined by the presence of anti-delta was relatively high in asymptomatic HBs Ag carriers (33%) and in HBs Ag positive cirrhosis patients (21%). Active ongoing HDV infection, detected by serum HD Ag and anti-delta IgM, was shown in five patients with cirrhosis and active hepatitis B virus replication. We conclude that hepatitis delta virus may be endemic in Tunisia and does not always inhibit hepatitis B virus replication.

Twenty-five Tunisian families were analyzed for their complement alleles in order to detect duplications at the C4 loci. In this population, the most characteristic duplications are C4A2, B1.12 or C4A1, B1,12 always associated with BFS07 and C2C. This previously undescribed C4B1,12 duplication was found in seven families, five times in association with HLA-A2, B50.

Sera obtained from fifty-five patients with active systemic lupus erythematosus (SLE) and from four patients with mixed connective tissue disease (MCTD) previously shown by immunofluorescence and by double immunodiffusion to possess antinuclear antibodies, were tested for the presence of natural antibodies of IgG, IgA, and IgM isotypes. Antibody activity to actin, myosin, DNA, TNP, albumin, and tubulin was examined, using an enzyme-linked immunosorbent assay (ELISA). It was found that, in comparison with the antibody titers in normal sera, most of the SLE and MCTD sera possessed statistically greater amounts of IgG, IgA, and IgM antibodies directed against all the antigens tested. Furthermore, the IgG, IgA, and IgM antibody activity to DNA and TNP, compared to that found with all the other antigens, was significantly higher. Antibodies reacting with a saline extract of calf thymus (ECT) were studied by ELISA and by immunodiffusion. No correlation was observed between the natural antibody titers and the serum antibody levels to ECT detected either by ELISA or by immunodiffusion.

Using immobilized anti-C3 antibody and an enzyme immunoassay, sera from 26 patients (eight with systemic lupus erythematosus (SLE), four with Hashimoto's thyroiditis, eight haemophiliacs and six with post-hepatitis cirrhosis) containing high levels of circulating immune complexes (IC) were selected. The IC were precipitated with 2.5% polyethylene glycol, washed, treated with acid buffer, neutralized and tested using an enzyme immunoassay in parallel with the original sera for antibody activity against a panel of antigens: human myosin and thyroglobulin, mouse actin and tubulin, calf thymus DNA and trinitrophenyl coupled to bovine serum albumin (TNP/BSA). It was found that all the isolated IC may contain IgG, IgA and IgM antibodies reacting with actin tubulin and TNP/BSA and also, depending upon the disease, antibodies sera with some of the other antigens of the panel. By comparison to the antibodies present in the original sera, higher titers of antibodies were found in the isolated IC while some antibody specificities not detected in a given serum were occasionally noted in the isolated IC. The antibodies present in the IC seem to possess characteristics similar to those of polyreactive human natural autoantibodies. It is concluded that natural autoantibodies participate actively in the formation of IC found in pathological sera.

There is no doubt that the autoimmune process in human disease depends on genetic factors. Varying associations were noticed between HLA DR and autoimmune disorders. The frequency of HLA-A-B and DR antigens as well as the Bf and C4 allotypes have been investigated in insulinodependant diabetes mellitus (IDDM) and compared to that of healthy controls in Tunisian population. An increase of A30, DR3, DR4, BfF1, C4AQ0 and C4BQ0 and decrease of B40, DR2, DR5 and DR6 were found in diabetes when compared to the value observation controls. The strongest association was noticed with HLA, DR3 and DR4. The prospective role of DR2 and DR5 antigens were also confirmed. Examination of HLA, Bf and C4 alleles. Two supratypes associated with IDDM have been observed among the Tunisian patients.

Two patients with non-systemic idiopathic glomerulonephritis were found to have a complete deficiency of C2, the second component of complement; the clinical course and serological abnormalities are reported in detail. An immunogenetic analysis of the patients of two families was carried out. It was demonstrated that the homozygous C2 deficiency was associated with homozygosity for HLA-A25-B18-DR2-BfS-C4A4-C4B2 haplotype.

The clinical significance of antibodies directed against extractable nuclear antigens with currently well-known antigenic targets, is studied in 100 patients affected with various connective tissue inflammations. The anti-Sm is the most frequently encountered antibody in lupus disease and overlapping connective tissue inflammations with a lupus component while the anti-RNP is related to mixed inflammation of the connective tissue and the dry syndrome. These antibodies, without being specific markers for a given disease, represent an additional biological argument for a better nosological classification of connective tissue inflammations. The use of immuno-impression, a more sensitive technique than immunodiffusion, could provide a better understanding of the immune response during these diseases and specify the diagnostic and prognostic value of various auto-antibodies. Analysis by immuno-impression of 36 sera among the 100 with antibodies directed against extractable nuclear antigens has enabled us to compare the two techniques and study the different specificities of these antibodies.