Ankylosing spondylitis, HLA-B27 positivity and the need for biologic therapies

HLA-B27 positivity strongly influences Ankylosing spondylitis (AS) disease susceptibility and phenotype. The aim of this study was to analyse an AS cohort with respect to quality of life (ASQoL), extra-articular disease, markers of disease activity (BASDAI), functional capacity (BASFI), biologic requirement, and the influence of HLA-B27 on these parameters.

Data recorded in 82 patients included demographics (age, sex), extra-articular disease (GI, ocular, dermatological, GU), cardiac and pulmonary diagnoses. BASDAI, BASFI, ASQoL, joint counts, disease duration and past/present treatment (NSAID, DMARD, steroid and biologic use) were also recorded.

90.2% of the cohort was B27 positive with significantly longer disease duration (17.6 v 6.9 years, p<0.05). BASFI (42.2 v 5.9), BASDAI (3.22 v 1.3), ASQoL (10 v 4), physician assessment of biologic need (24 v 5), steroid (15.7% v 12.5%) and NSAID use (98.6% v 75%) were higher in the B27 positive group, as were ocular (38.9% v 12.5%), pulmonary (4.2% v 0%) and cardiac (4.3% v 0%) features. Negative patients displayed more GI (37.5% v 19.4%), dermatological (25% v 19.7%) and GU (25% v 4.2%) features. Patients satisfying ASAS (AS assessment study group) criteria and receiving biologic therapy were 18.9% (B27 positive group) and 0% (B27 negative group).

AS patients have significantly longer disease duration if B27 positive, higher markers of disease activity, poorer functional status, poorer quality of life, and more extra-articular manifestations. These findings were reflected in the percentage of patients needing biologic therapies.