Abstract
Abstract: :
Purpose: The genetic polymorphism of the DR beta chain (DRB) of HLA class II molecules was found to influence the immune response to antigens. Previous studies involving North American populations of Caucasian origin suggested an association of pars planitis with HLA-DR2 or its allelic subtype HLA-DR15. This study was performed to investigate the frequency of HLA-DR alleles in Scottish patients with pars planitis. Methods: A review of the uveitis data base of the Grampian University Hospitals was conducted to identify patients with pars planitis. The patients underwent a full ophthalmological examination, ultrasound biomicroscopy for the quantitative analysis of ocular inflammatory activity and blood tests to exclude systemic disease. Inclusion criteria were: vitritis, snowbanks in at least one eye and vitreous cells or debris in the fellow eye. Patients with a systemic autoimmune disease were excluded from the study. The control group was composed of 34 age and sex matched randomly selected healthy blood donors from the same ethnic background. HLA class II (DRB1) typing was performed using PCR sequence specific primer sets (PCR-SSP). HLA types were assigned based on the PCR-SSO patterns with high resolution subtyping of DR15 alleles by PCR-SSP using WHO nomenclature. Results: 15 consecutive patients were included in this study. HLA-DR15 (DRB1*15) was found in 2 patients and 8 persons in the control group. All DRB1*15 positive persons were further subtyped and found to be DRB1*1501. The frequency of HLA-DR15 in the patient population did not differ significantly from healthy controls. The frequencies of other HLA-DRB1 alleles were not significantly different between the patient population and the control group. Conclusion: In contrast to previous studies on populations from different geopgraphic regions, the frequency of HLA-DR15 is not increased in Scottish patients with pars planitis. Thus, additional risk factors seem to be important in the pathogenesis of this disease.
Keywords: 612 uveitis-clinical/animal model • 420 genetics • 355 clinical (human) or epidemiologic studies: risk factor assessment