Background Spinal ankylosis is one of the important factor responsible of functional impairment in ankylosing spondylitis (AS). In advanced disease, there is still the debate of the potential benefit of use of TNF blockers since one could expect irreversible disability.
Objectives To evaluate the TNF blocker retention rate in AS patients with regard to the presence of spinal ankylosis
Methods a) Patients; AS patients receiving any anti TNF blocker since 2005 and included in the HÜR-BİO (Hacettepe University Rheumatology Biologic Registry: a single center biological registry)
b) Data collected at baseline included demographics, co-morbidities, smoking status, TNF blochers (infliximab, etanecept, adalimumab and golimumab), available disease activity parameters (such as BASDAI, BASFI, CRP, ESR, global VAS). Available digital radiographic imaging of lumbar spine radiographies were reassesed for spinal ankylosis by a single physician (UK). Advanced spinal ankylosis was defined as the presence of at least two intervertebral adjacent bridges at the lumbar spine level (1). The date of initiation and the date of discontinuation (or the date of the last visit under therapy) of the TNF blocker was collected.
c) Analysis: A part from the comparison of the baseline characteristics in the two groups of patients (with or without advanced spinal ankylosis), retention rate was evaluated using the Kaplan-Meier technic and log rank tests were used to compare such retention rate in the different groups of patients with regard to the presence and the severity of the ankylosis.
Results Since 2005, TNF blocker therpy was intiated in 630 patients, lumbar radiography was available in 530 of them (male: 66%; age: 41±11 years old; disease duration was 9.7±7.2 years). Advanced spinal ankylosis was observed in 99 (19%%) patients. Patients received either etanercept [199 (37.5%)], infliximab[192 (36.2%),], adalimumab [117 (22.1%)] or golimumab [22 (4.2%)] Baseline disease activity parameters were similar in the two groups of patients: [BASDAI score 5.7±1.6 vs 5.7±1.7, p>0.05, BASFI score 5.2±2.5 vs 4.5±2.5, p>0.05, ESR 35±21 vs 32±23 mm/hour, p>0.05, CRP 3.4±4.6 vs 3.1±3.0 mg/dl, p>0.05 in the patients with versus without advanced spinal ankylosis, respectively]. However, CRP level (1.94±3.57 vs 1.08±1.62 mg/dl, p=0.003) and BASFI score (3.99±2.51 vs 2.43±2.18, p<0.001) were higher in advanced spinal ankylosis group at last visit. Mean TNFi duration was 37±30 months. Patients with advanced spinal disease had better drug retention rate in comparison to the patients without such spinal ankylosis (log Rank p=0.020) (Fig. 1).
Conclusions Our data confirm the efficacy of TNF blockers even at advanced phase of the AS disease with a drug retention rate even geater in comparison the the one in patients without spinal ankylosis. Further studies are required in order to adress the benefit of physical therapy in these patients receiving a TNF blocker
Ann Rheum Dis 2011;70:799–804.
Disclosure of Interest None declared