S. Feki

The intrathecal polyspecific antiviral immune response (MRZ reaction): A potential cerebrospinal fluid marker for multiple sclerosis diagnosis

We tested the performance of MRZ-reaction, an intrathecal humoral immune response against-Measles (M), Rubella (R) and Varicella Zoster (Z) viruses, in multiple sclerosis (MS) diagnosis. The MRZ-reaction was significantly more positive in MS than in non-MS group with a specificity of 91.9%. In MS group, the RZ-profile was the most prevalent and the R-specific antibody-index was correlated to the number of oligoclonal bands (OCB) in CSF. Interestingly, the MRZ-reaction was detected in 53% of OCB-negative-MS patients. The MRZ-reaction seems to be a relevant CSF diagnostic marker of MS disease. The likely relation between its positivity and the vaccination status deserves to be investigated.

HLA Class III: A susceptibility region to systemic lupus erythematosus in Tunisian population

Background and objectives Short tandem repeats (STR) are usually used as informative polymorphic markers for genetic mapping and for disease susceptibility analysis. The involvement of these microsatellite markers localized in the MHC region was reported in many auto-immune diseases. In this study we analyzed for the first time eight polymorphisms of microsatellite loci at the HLA region: D6S291, D6S273, TNFa, b and c, MICA, D6S265 and D6S276, in Tunisian systemic lupus erythematosus (SLE) patients. Materials and methods We performed a case control study in which the microsatellite loci were amplified using specific primers labeled with NED, VIC, PET or 6-FAM and analyzed using GeneScan software 3.7. For the statistical analysis, we used SPSS software and we performed a sub-haplotype scoring test using the haplo.stats software developed in the R language. Results We found that two mean associated regions existed; the most statistically significant encompassed the 3 TNF markers (p = 0.0003, OR = 19.34); the latter covered the DR region. In fact, when scoring haplotypes in 3 marker- sliding windows, the p value increased as we moved away from the TNF region and decreased again when we approached the DRB1 locus. We also established for the first time the negative association between alleles of D6S291 and SLE. The majority of clinical and serological correlations were noted with TNF alleles. Conclusion Our results confirm the association between TNF and DRB1 polymorphisms and SLE. The association between alleles of D6S291 and SLE needs however to be verified by the analysis of other markers beyond this region.

Pemphigus herpetiformis in South Tunisia: a clinical expression of pemphigus foliaceus?

Pemphigus herpetiformis (PH) is a rare subtype of pemphigus combining clinical features of dermatitis herpetiformis and the immunopathologic characteristics of pemphigus. We aimed to analyze the epidemiological, clinical, and immunological presentation and management of the disease in a cohort of south Tunisian patients with a long‐term follow‐up.

Positivité des anticorps anti-cytoplasme des polynucléaires neutrophiles chez l’enfant : prévalence et étiologies

In adults, anti-neutrophil cytoplasmic antibodies (ANCA) are considered as serological markers of several diseases, especially vasculitis and glomerulonephritis. Since ANCA are rarely positive in children, few data about the clinical relevance of these auto-antibodies in pediatric population have been reported. Therefore, our study aims to describe the spectrum of disorders associated with positive ANCA in Tunisian children. This study had been carried out over a period of 12 years and a half. All patients under the age of 15 for whom ANCA screening was performed in our laboratory were included. Clinical data were collected retrospectively. Indirect immunofluorescence (IFI) technique for ANCA detection was performed using PNN smears fixed with ethanol, formalin and, if necessary, methanol. Positive results were tested using immunodot to characterize the antigenic targets (myeloperoxydase (MPO) and proteinase 3 (PR3)). Our results showed that 410/5,990 (6.8%) laboratory requests for ANCA screening were for children. Forty (9.7%) requests were positive (24 children). Clinical data were available for 19 patients only. Sex-ratio (F/M) was 1.25. The mean age was 9 years and a half (3-15 years). The most frequent IIF patterns were x-ANCA (n=12) and p-ANCA (n=7). In our patients, the most frequent conditions associated to ANCA were treatment with benzylthiouracil for hypothyroidism (n=6), inflammatory bowel disease (n=4) and hemolytic anemia (n=4). In conclusion, the positivity of ANCA in children seems to be a rare event. Associated conditions include clinical disorders specific to the pediatric population. Treatment with benzylthiouracil is an etiology to be taken into consideration.

Genetic association and phenotypic correlation of TLR4 but not NOD2 variants with Tunisian inflammatory bowel disease

The common association between NOD2/CARD15 and TLR4 gene variants with inflammatory bowel disease (IBD) has not been replicated in all studies. We studied the polymorphism of these two genes in Tunisian patients with IBD.