[Show abstract][Hide abstract] ABSTRACT: 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.
[Show abstract][Hide abstract] ABSTRACT: Chemokines play a major role in the process by which leukocytes are recruited from the bloodstream into the sites of inflammation. Genes for the chemokine receptors CCR5, CCR2 and MCP-1 are characterized by functional polymorphisms implicated in transplant rejection. To investigate this association, we analyzed polymorphisms of CCR5-∆32, CCR5-59029-A/G, CCR2-V64I and MCP-1 G/A (-2518) in 173 renal transplant recipients and 169 healthy blood donors. The patients were classified in two groups: Group-1 (G-1) included 33 HLA-identical recipients and Group-2 (G-2) included 140 (one or more) mismatched graft recipients. Forty-two patients had developed acute rejection episodes (ARs): seven in G-1 and 35 in G-2. Thirteen G-2 patients developed chronic allograft dysfunction (CAD). The genotypic and allelic frequencies of all polymorphisms studied did not reveal significant differences between patients and controls and among G-1 and G-2 recipients. However, a significant risk of acute renal transplant rejection was found in G-1 patients who possessed the CCR2-64I allele (odds ratio 0.24, 95% confidence inter-val [CI], 0.05-1.06; P = 0.035). There was no significant association of this polymorphism and CAD. In conclusion, the observed association of CCR2-64I with AR should be added to the spectrum of immunogenetic factors known to be involved in allograft renal loss.
Saudi journal of kidney diseases and transplantation: an official publication of the Saudi Center for Organ Transplantation, Saudi Arabia 01/2011; 22(1):18-23.
[Show abstract][Hide abstract] ABSTRACT: Crohn's disease (CD) and ulcerative colitis (UC) have complex genetic background that is characterised by more than one susceptibility locus. To detect a possible association between the functional polymorphisms of the chemokine receptors CCR5, CCR2 and MCP-1 genes and susceptibility to CD and UC in Tunisian population, polymorphisms of CCR5-delta32, CCR5-59029-A/G, CCR2-V641 and MCP-1-2518-G/A were analysed in 194 Inflammatory bowel disease (IBD) patients and 169 healthy blood donors using PCR-RFLP and PCR-SSP methods. The patients were classified in 126 patients with CD and 68 patients with UC. The genotypic and allelic frequencies of all polymorphisms studied, did not reveal significant differences between patients and conrols and among CD and UC patients. However, analysis of CD patients revealed that those without homozygosous G/G genotype are more frequently in remission compared to those with this genotype (OR: 0.4, 95% CI: [0.174-0.928]; p = 0.03). Also, the frequency of the CCR2-641 muted allele was statistically higher in CD patients in remission disease than those in active form (OR: 0.267 95% CI: [0.09-0.78]; p = 0.01). Adjustment for known covariates factors (age, gender and immunosuppressive regimen) confirmed these univariate findings and revealed that the CCR5-59029-A/G and CCR2-V64I genotype were associated to remission form of CD (OR: 263; 95% CI: [1.01-6.80]; p = 0.047 and OR: 4.64; 95% CI: [1.01-21.31]; p = 0.049 respectively). In conclusion, the present study supports the involvement of chemokine receptor (CCR2 and CCR5) polymorphisms in activity degree of the IBD disease in Tunisian patients.
Archives de l'Institut Pasteur de Tunis 01/2011; 88(1-4):47-58.
[Show abstract][Hide abstract] ABSTRACT: We carried out a protein and genetic investigation of the factor H gene mutations within two families presenting with a diagnostic suspicion of atypical hemolytic uremic syndrome (aHUS). The results within the patients of the first family revealed a factor H-deficiency. Direct sequencing allowed the detection of a 4-nucleotide deletion in the factor H gene. This deletion was found as the homozygote form in the proband and as the heterozygote form in the parents. Protein and functional analyses of the complement system were normal in all members of the second family. However, the molecular investigation for the father showed the presence of an amino acid substitution in the FH gene. Unfortunately, his two affected children died without being investigated for mutations. The functional consequences of these abnormal proteins are still to be demonstrated.
International Journal of Nephrology and Renovascular Disease 07/2010; 3:85-92.
[Show abstract][Hide abstract] ABSTRACT: To assess the possible association between PTPN22 (R620W) gene polymorphism and inflammatory bowel disease (IBD).
One hundred and sixty-four patients with IBD [105 Crohn's disease (CD) and 59 ulcerative colitis (UC)] and 100 healthy controls were recruited. Genotyping of the PTPN22 gene 1858C-->T polymorphism was performed by restriction fragment length polymorphism-polymerase chain reaction with RsaI digestion.
The genotypic and allelic frequencies of (R620W) PTPN22 gene polymorphism reveal a significant association of the PTPN22 620-W allele with IBD, compared to the healthy control group (OR: 17.81, 95% CI: 4.18-21.86, P = 0.00001). Nevertheless, no difference in this polymorphism was found between CD and UC patients. No significant association was found between the frequencies of genotypes of the PTPN22 gene with either the clinical features such as sex, age, age at disease onset, and extent of colitis, or the production of serological markers (anti-Saccharomyces cerevisiae antibody in CD and perinuclear anti-neutrophil cytoplasmic antibody in UC).
These observations confirm the association of IBD susceptibility with the PTPN22 1858T (620-W) allele in Tunisian patients.
World Journal of Gastroenterology 01/2010; 16(4):479-83. · 2.37 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: CTLA-4 and CD28 are T lymphocyte receptors involved in the regulation of T-cell activation. Allograft rejection is an alloimune response which is strongly dependent on T-cell proliferation. Thus, we examined the relationship between CTLA-4 and CD28 gene polymorphisms and renal transplant outcomes. We genotyped 141 renal recipients and 229 healthy controls using PCR-SSP methods for the (-318) C/T polymorphism in the promoter region of the CTLA-4 gene and IVS3 (+17) T/C on intron 3 of the CD28 gene, and by PCR-RFLP method for exon 1 (+49) A/G and CT60 G/A within the 3'-untranslated region (UTR) of the CTLA-4 gene. Patients were classified into two groups: Group I included 23 HLA-identical haplotype allograft recipients and group II, 118 recipients with one or more mismatches in HLA haplotypes. Thirty-six patients developed at least one acute rejection episode (ARE). No significant differences were observed between the genotypes or the allele distribution between ARE and non-ARE patients. However, in group I, (+49) A and CT60 (G) allele frequencies were lower in patients with ARE than those without ARE (0.100 and 0.400 vs 0.361 and 0.722 respectively). However, the difference was not significant. Our study suggested that these alleles may confer protection against renal allograft loss.