Ab0992 the potential impact of hla-b27 and hla-b51 haplotype on patterns of non-infectious uveitis

Background Non-infectious uveitis (NIU) include diseases characterized by the inflammation of the vascular tunica of the eye that can cause significant ocular impairment up to blindness, and systemic inflammatory rheumatic diseases (RDs) represent one of their major causes [1]. NIU can be widely heterogeneous in terms of course, laterality, and anatomical involvement, while their clinical presentation may be influenced by associated RDs and certain HLA haplotypes [2]. Objectives To explore the potential impact of HLA-B27 and HLA-B51 haplotypes on clinical presentation of NIU from patients who were referred to a 3rd level Rheumatologic Clinic in Italy. Methods A cross-sectional study was conducted. Selection criteria consisted of having a diagnosis of NIU in an age of onset ≥ 18 years old regardless of etiology among patients who were admitted to the 3rd level Rheumatologic Clinic at “Tor Vergata” University Hospital (Rome, Italy) between January 2018 and October 2022. Data were collected from medical records: age of NIU onset, recurrence and anatomic patterns of affected eyes according to the Standardization of Uveitis Nomenclature (SUN) working group, HLA-B27 and HLA-B51 positivity, and associated RDs were analyzed. Results Among the NIU cohort (n= 144), 76 of them underwent HLA-B haplotype typing: 26 (34.2%) showed HLA-B27 positivity while 16 HLA-B51 positivity (21.1%), without a gender difference. Patients HLA-B27(+) had more frequently anterior NIU (AU, 88.5% vs 60%, p=0.01), acute course (69.2 vs 44%, p=0.03), and unilateral involvement (69.2% vs 42%, p=0.02) than patients HLA-B27(-) (Figure 1). HLA-B27(+)-NIU had a significantly prevalent diagnosis of axial-spondylarthritis (ax-SpA, 53.8% vs 6%, p<0.00001) than HLA-B27(-)-NIU. Differently, patients with HLA-B51(+) had mostly posterior NIU (PU, 68.8% vs 16.7%, p<0.00005), recurrent/chronic course (68.8% vs 40%, p=0.04), and bilateral involvement (81.3% vs 33.3%, p=0.0005) than patients HLA-B51(-) (Figure 1). A diagnosis of Behçet’s Disease (BD) was performed more frequently in HLA-B51(+) than in HLA-B51(-) patients (75% vs 6.7%, p<0.00001). The age of NIU onset was significantly younger in HLA-B51(+) than in HLA-B51(-) (34.1±13.8 vs 41.1±13.2 yo, p=0.003), while there was no statistically significant difference in age of NIU onset between HLA-B27(+) and HLA-B27(-) (38.38±13.7 yo vs 40.49±13.5 yo. p>0.05). Conclusion Our population-based findings describe how HLA-B27 and HLA-B51 haplotypes can impact NIU patterns and suggest a relevant role of an early HLA typing study of NIU patients for the definition of targeted diagnostic and therapeutic strategies. References [1]Generali E, Cantarini L, Selmi C. Ocular Involvement in Systemic Autoimmune Diseases. Clin Rev Allergy Immunol. 2015 Dec;49(3):263-70. doi: 10.1007/s12016-015-8518-3. PMID: 26494481. [2]Hysa E, Cutolo CA, Gotelli E, Pacini G, Schenone C, Kreps EO, Smith V, Cutolo M. Immunopathophysiology and clinical impact of uveitis in inflammatory rheumatic diseases: An update. Eur J Clin Invest. 2021 Aug;51(8):e13572. doi: 10.1111/eci.13572. Epub 2021 May 5. PMID: 33851422; PMCID: PMC8365741 Figure 1. Ax-Spa, axial-spondyloarthritis; BD, Behçet Disease * p<0.01; **p<0.001; *** p<0.0001; ****p<0.00001 Acknowledgements: NIL. Disclosure of Interests None Declared.