Purpose: To establish a human leukocyte antigen (HLA) association in a homogeneous population of patients with pars planitis.
Methods: A strict set of inclusion parameters was established for the diagnosis of pars planitis. Forty patients with pars planitis who met these criteria underwent HLA analysis of class I and II phenotypes.
Results: HLA-B8 was present in 15 (37.5%) of 40 patients versus 85 (19.7%) of 431 controls (relative risk, 2.44; P = 0.011). HLA-B51 was present in 9 (22.5%) of 40 patients versus 51 (11.8%) of 431 controls (relative risk, 2.16; P = 0.049). HLA-DR2 was present in 27 (67.5%) of 40 patients versus 121 (28.0%) of 431 controls (relative risk, 5.32; P < 0.0001). HLA-DR2 has been associated with multiple sclerosis (MS). Exclusion of five patients with pars planitis in whom MS subsequently developed did not change the significance of these findings.
Conclusions: The strongest association of pars planitis with HLA-DR2 and the temporal development of MS in some patients with pars planitis further supports an association between pars planitis and MS.