Allelic variation in HLA-DRB1* loci in Syrian pemphigus vulgaris patients.

BACKGROUND: Pemphigus vulgaris (PV) is known to be strongly associated with particular alleles of the human leukocyte antigen (HLA)-DRB1* loci. However, to date, the association of HLA with pemphigus has not been studied in a Syrian population. OBJECTIVES: We aimed to study HLA-DRB1* loci variation in Syrian PV patients. METHODS: We used a sequence-specific primer polymerase chain reaction method to define the allele type of the DRB1* loci in 91 patients with PV and 270 healthy control subjects. RESULTS: We noticed an increased frequency of HLA-DRB1*04 and DRB1*14 alleles in patients with PV compared with healthy control subjects (67.0% vs. 26.3%; odds ratio [OR] = 5.7, corrected P < 0.0001 for DRB1*04; 54.9% vs. 11.0%; OR = 9.5, corrected P < 0.0001 for DRB1*14). Among DRB1*04-positive PV patients, the DRB1*402 subtype was markedly increased compared with DRB1*04-positive healthy controls (84.3% vs. 26.7%; corrected P = 0.002), whereas the DRB1*0403 variant was represented more commonly in DRB1*04-positive healthy individuals than in DRB1*04-positive PV patients (45.0% vs. 1.6%; corrected P < 0.0001). In addition, the frequency of DRB1*11 was significantly decreased in PV patients compared with healthy controls (19.7% vs. 50.4%; OR = 0.25, corrected P < 0.0001). CONCLUSIONS: The occurrence of PV is positively associated with HLA-DRB1*14 and HLA-DRB1*0402 but negatively associated with HLA-DRB1*11 in the Syrian population.

HLA-B27 and its subtypes in Syrian patients with ankylosing spondylitis.

OBJECTIVE: To assess HLA-B*27 and its subtypes associated with ankylosing spondylitis (AS) in Syrian patients. METHODS: A polymerase chain reaction with specific sequence primer method were used to study the HLA-B* locus polymorphism in 50 Syrian patients fulfilling the modified New York criteria for classification of ankylosing spondylitis and 217 unrelated healthy Syrian controls. Patients were recruited from the Outpatients Department, Alassad University Hospital, Damascus, Syria between December 2006 and December 2007. The study took place at the Laboratory for Research and Genetic Consultations, Faculty of Medicine, Damascus University, Damascus Syria. RESULTS: HLA-B*27 allele was found in 1.4% healthy Syrians and 60% in patients with AS (OR=107, p=0.0001, corrected p=0.003). The most common HLA-B*27 variants in patients were B*2705, which was found in 67% of patients, followed by B*2702 found in 20% of patients. HLA-B*27 was identified in all cases with uveitis, peripheral arthritis, and positive family history. CONCLUSION: Although HLA-B*27 allele frequency in this group of Syrian patients with AS is lower compared to the noted AS patients in many populations, its association with the disease risk in our population seems to be the strongest one. If confirmed by larger study, this finding may be of great interest, particularly for diagnosis at disease onset where some clinical features as uveitis and peripheral arthritis may precede the fulfilling of all standard criteria for AS diagnosis.