Abstract
Purpose :
To investigate an association between human leukocyte antigen genotype A29 (HLA-A29) subtypes and birdshot chorioretinopathy (BSCR) disease severity. Additionally, we investigated the possible association of patient demographics, including place of birth and upbringing, with BSCR subtypes. This was a combined prospective/retrospective chart review of patients with BSCR at the University of Ottawa Eye Institute.
Methods :
HLA-A29 subtyping was done through high resolution DNA sequencing using DNA samples from a blood draw. Mean best-corrected visual acuity (BCVA) was used as a surrogate marker for disease severity, with worse mean BCVA indicating advanced BSCR disease. BCVA was converted from Snellen Chart into logarithm of the minimum angle of resolution (logMAR). Demographic and geographic data was obtained through a patient survey.
Results :
24 patients with BSCR were identified through a retrospective chart review and 10 patients participated. All 10 research participants were of subtype HLA-A*29:02. No other subtypes were found in the study patient population. 35% of patients were of French background, 6% English, 29% Irish, 24% Scottish, and 6% Ukrainian. Differences in mean BCVA were not statistically significant for correlation with ethnic background, city of birth, city of upbringing, city of birth of the patient’s mother or city of birth of the patient’s father.
Conclusions :
As only HLA-A*29:02 subtypes were identified,, no conclusions can be drawn about HLA-A29 subtype and disease severity. However, our findings strengthen the observation that HLA-A29 is predominantly found in the Caucasian population. Additionally, it was determined that there is no difference in disease severity for ethnic background, city of birth, city of upbringing, city of birth of the patient’s mother, and city of birth of the patient’s father. Future steps may include acquisition of additional data from a geographically distant second eye clinic to increase the sample size and identify alternate HLA-A*29:02 subtypes.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.