CD86 +1057G>a polymorphism and susceptibility to acute kidney allograft rejection

CD86 is a costimulatory molecule that participates in the regulation of T-cell lymphocytes activation. Thus, we examined a genetic marker on the CD86 gene in kidney transplant outcome. In our retrospective study, 168 kidney allograft recipients were genotyped by direct sequencing. Patients were classified into 2 groups of 29 human leukocyte antigen [HLA]-identical haplotype allograft recipients and 139 recipients showing one or more mismatches in the HLA haplotype. Forty-five patients [26.8%] developed at least 1 acute rejection [AR] episode, 7 in the first and 38 in the second group. Acute rejection was associated with the presence anti-HLA antibodies before transplantation [P=.03]. The AA genotype and A allele at position+1057 in the CD86 gene were more frequent in patients without AR [9.75% and 28.5%, respectively] compared with those showing an AR [2.22% and 23.3%, respectively]. This difference was statistically significant in the anti-HLA-positive recipients, as AA frequency was 31.3% in non-AR patients and zero in AR ones [P=.04] and A allele frequency was 46.9% and 20.8%, respectively [P=.04]. Patients bearing AA genotype reached a higher graft survival time [9.84 years] than those carrying GA [8.21 years, P=.32] or GG [7.61 years, P=.72] genotypes. These results suggest that AA genotype and A allele of CD86+1057G>A polymorphism may confer a protection against acute kidney allograft rejection in Tunisian patients

[Neonatal screening of congenital toxoplasmosis. Prospective study]

While toxoplasmosis infection in women is often benign, transmission of maternal infection to the fetus can lead to severe sequelae. Because the majority of patients with acute toxoplasmosis are asymptomayic, a systematic serologic screening program will needed with monthly serologic screening of all seronegative pregnant women until delivery. The aim of this study was to identify cases of congenital toxoplasmosis among all live births of women found to be seronegative in pregnancy once at least. During a prospective study period of 16 months [from 07/02/2003 to 30/06/2004] we conduct a neonatal screening of all live births of women found to be seronegative in pregnancy once at least. Peripheral samples were obtained from every couple mother/ infant. Serological methods performed for diagnosis of toxoplasma specific IgM and IgG antibodies were Hemaglutination and Enzyme-linked immunosorbent assay [ELISA]. Four cases of congenital toxoplasmosis were diagnosed after birth. All cases were asymptomatic and a specific treatment was started soon after diagnosis. The clinical and serologic evolution was normal in three cases. A serologic rebound at two years was reported in one case with a chorioretinitis in the examination of the ocular fundus. Neonatal as well maternal screening during pregnancy and at birth should be systematic to prevent, diagnose and treat early the affected neonates usually asymptomatic

[Vascular trombosis of renal graft: 9 cases]

Allograft renal thrombosis can occur in 1 to 6% of cases. Many predisposing factors has been identified especially alteration of coagulation. We analyzed in this study frequency and predisposing factors of renal graft thrombosis. We report a retrospective study including 319 renal transplant recipients. Nine patients [2, 8%] presented veinous graft thrombosis in 5 cases and arterial thombosis in 4 cases. There were 6 men and 3 women aged of 30, 6 years meanly [10-56] which developed the thrombosis 6 days [1-48] after the transplantation. All patients were detransplanted after 16, 2 days and 1 patient died. Thrombosis constitute an important cause of graft loss. A perfect surgical technic and prophylactic treatment in high risk patients are necessary to reduce this complication

involvement of HLA - DRBI *, DQAI *, DQBI *and complement C4 loci in diadnosing systemic lupus erythematosus among Tunisians

Genetic susceptibility to systemic lupus erythematosus [SLE] varies among populations. Few data exist on associations of HLA class II and class III alleles of the major histocompatibility complex [MHC] and susceptibility to SLE in Tunisians. Patients and We compared HLA-DRB1*, DQA1, DQB1* and C4 allotypes in 62 Tunisian SLE patients and 100 matched controls. We also assessed the association of specific alleles with distinct autoantibody profiles in SLE patients. HLA-DRB1*0301, -DRB1*1501 and C4AQO alleles were increased in the SLE patients, while the frequencies of HLA-DRB1*04 and DQB1*03 were decreased. HLA-DQA1*0102 and DQA1*0501 were significantly increased in the SLE patients. HLA-DQB1*0201 and DQB1*0602 were more frequent in the SLE patients. C4A*QO and C4B*QO were increased in frequency in the SLE patients compared to the controls, but only C4A null was significantly increased. Eleven of 17 SLE patients with the C4 null allele were HLA-DRB1*0301 positive. Three of 16 SLE patients with HLA-DRB1*1501 were associated with HLA-DQB1*0501 rather than DQB1*0602, as has been reported in European SLE patients.Conclusions: The MHC class II alleles [DRB1, DQA1, DQB1] and C4 null associations noted in other ethnic groups are also found in Tunisians, suggesting shared susceptibility factors across ethnic lines in predisposition to SLE. In contrast to other ethnic groups, MHC class II alleles are not associated with the presence of specific autoantibodies in Tunisian SLE patients