Human leukocyte antigen typing in Iraqi multiple sclerosis patients

OBJECTIVE: To assess the relative frequency of human leukocyte antigen (HLA) class I and class II in Iraqi multiple sclerosis (MS) patients, and to ascertain whether they offer any etiologic or protective role.

METHODS: We conducted this study in the Baghdad MS Clinic and Teaching Laboratory Institute, Medical City, Baghdad Teaching Hospital, Baghdad, Iraq from March to July 2004. We enrolled 44 randomly selected MS patients and 69 healthy unrelated age- and sex-matched controls. We carried out HLA class I and class II typing on both groups using the microlymphocytotoxicity test.

RESULTS: The HLA class I typing revealed no consistent association between MS and HLA-A and -Cw, while HLA-B5 and -B44 were found to possibly be risk factors for MS with odds ratio (OR) of 10.2 for -B5 and 4.4 for -B44. The HLA-B35 may form a protective factor with OR of 0.1. The HLA class II typing revealed an etiologic risk for HLA-DR4 (OR=10.3) and a protective effect for HLA-DR2 (OR=0.3) and -DR7 (OR=0.2), and etiologic effect for -DQ1 (OR=3.3) and -DQ3 (OR=3).

CONCLUSION: The HLA DR4 carries the strongest association with MS in Iraqi patients. This study adds to the well-known diversity of HLA-allelic association of MS in different populations, and emphasizes the complexity of genetic susceptibility to MS.