Pars planitis - Clinical features and class II HLA associations

Objective: To describe a cohort of patients with pars planitis followed at a single tertiary care institution, determine the frequency of multiple scl erosis and/or optic neuritis in patients with this disorder, and calculate gene frequencies of human leukocyte antigen (HLA) class II alleles in these patients. Design: Fifty-three patients with the diagnosis of pars planitis underwent clinical record review or telephone interview for follow-up or both; 32 of these underwent phlebotomy for analysis of HLA class II alleles, Main Outcome Measures: Outcomes included visual acuity, occurrence of multi ple sclerosis and/or optic neuritis, and HLA class II gene frequencies. Results: With a mean follow-up of 2 years, approximately 90% of patients ma intained a visual acuity better than 20/40 in at least one eye. The most fr equently encountered ophthalmic complications included cystoid macular edem a, cataract, and epiretinal membrane formation. Of 37 patients with pars pl anitis who had medical or neurologic follow-up evaluations, 6 (16.2%) devel oped multiple sclerosis, The HLA-DR15 allele, coding for one of the two HLA -DR2 subtypes, was associated with pars planitis (odds ratio = 2.86, 95% co nfidence interval = 1.42-5.78, P = 0.004), Conclusions: A common immunogenetic predisposition to multiple sclerosis an d pars planitis may be associated with the HLA-DR15 allele, This associatio n may represent genetic linkage to the HLA-DR locus or a role for the HLA-D R15 gene product in the pathogenesis of both of these diseases.