SAT0538 CLINICAL PROFILE OF AUTOIMMUNE UVEITIS NOT ASSOCIATED WITH HLA B27: A RETROSPECTIVE SINGLE CENTER STUDY
Authors: V. S, S. Ganu, S. Surendran, L. Biswas, M. Cb, C. V. Marwaha
Journal: Annals of the Rheumatic Diseases (2020)

Background: Autoimmune uveitis is frequently referred to a rheumatologist for evaluation &amp; treatment. While clinical characteristics of HLA B27 associated uveitis are well documented, scanty information is available on non HLA-B27 associated autoimmune uveitis. We have described the clinical characteristics of our patients of non-B27 uveitis and compare the same with patients of Asian Indian HLAB27 uveitis. Objectives: To describe and compare the clinical characteristics of non HLA-B27 associated autoimmune uveitis. Methods: Retrospective review of records from hospital’s electronic medical record database and included all cases of autoimmune uveitis that were referred to rheumatology from January 2017 and December 2018. Among these, those who did not have HLA B tissue typing record or were HLAB27 positive; were excluded. Pertinent details like age, sex, no. of episodes, unilateral or bilateral, location of uveitis (anterior, posterior or pan uveitis, association of synechiae &amp; vasculitis), baseline CRP &amp; ESR levels along with the HLA B profile(SSP-PCR) &amp; nature of treatment received (systemic steroids, DMARD initiation) were collected. For comparison, clinical features of a HLA B27+ve uveitis series from the same ethnic Asian-Indian population were used 1 . Subgroup analysis was also done between the common non B27 HLA genotypes. Descriptive statistics were summarized using mean &amp; percentage. Chi square &amp; Fischer’s test was used to compare the groups and subgroups. Results: Out of total 210 patients screened, 17 cases were HLA B27 negative on HLA B tissue typing. The key demographic and clinical features of our patients of autoimmune uveitis not associated with HLA B27 in comparison with the B27 +ve uveitis group are given in table 1. Table 1 Comparison of clinical features of our patients versus B27 +ve uveitis Non HLA B27 Autoimmune Uveitis (N=17) Ninan et al (N=25) P value Age (years) at disease onset 16-35 4 15 More than 35 13 7 0.009 Onset not known 0 3 Sex Male 6 21 0.002 Female 11 4 Region of uveitis anterior 9 24 0.001 posterior &amp; pan-uveitis 8 1 Biochemical parameters CRP (mg/L) 6.45 + 8.39 N.A - ESR (mm/hr) 24.75 + 18.80 N.A Associated complications synechiae formation 4 of 17 4 of 25 0.69 retinal vasculitis 4 of 17 0 of 17 - Recurrent uveitis was seen in 11 out of 17 patients in our patients as compared to 15 out of 22 (p 0.81) in HLA B27 +ve patients. HLA B7 and HLA B35 were the most frequent genotypes (figure 1). Sub group analysis showed that 87.5% of patients with a component of posterior uveitis were HLA B7 or HLA B35 positive. It was noted none of 5 cases of HLA B35 +ve uveitis needed second line DMARD initiation after a tapering course of systemic steroids. There was no other significant difference in the clinical or treatment parameters noted in the subgroup analysis between the HLA genotypes. Conclusion: Autoimmune uveitis not associated with HLA B27 tends to have older age of onset, female predominance, more common involvement of posterior uvea and association of vasculitis than HLAB27 autoimmune uveitis. Among non HLA B27 uveitis, HLA B07 and HLA B35 are the most common serotypes in our Asian south Indian group. Therapeutic stratification for a delayed initiation of second line DMARD therapy needs to be studied further particularly in HLA B35 +ve uveitis. References: [1]Ninan F, Mathew J, Philip SS, John D, Danda D, John SS. Uveitis of spondyloarthritis in Indian subcontinent: a cross sectional study. Int J Adv Med 2017;4:1441-6 Disclosure of Interests: None declared