Background Systemic administration of tumor necrosis factor-alpha (TNF-α) antagonists, such as infliximab, has been shown to be effective in the treatment of spondyloarthropathies (SpA). However, experience with the local use of anti-TNF-α in patients with sacroiliitis, ankylosing spondylitis, or other forms of SpA is limited. The effects of intravenous infliximab therapy on MRI signs of sacroiliac joint (SIJ) activity and on clinical measures of disease activity has been previously demonstrated, however the effects of its local injection into SIJ is not yet studied.
Objectives To study the effects of local SIJ injection of infliximab on clinical and MRI signs of disease activity in early axial SpA.
Methods The study included thirty-seven patients fulfilling the ASAS criteria for axial SpA, with disease duration of less than one year, who failed to respond to non-steroidal anti-inflammatory drugs (NSAID). Patients with associated peripheral arthritis, psoriasis or inflammatory bowel disease were excluded. STIR, T2 Fat saturation and T1W MRI of spine and SIJ were performed for all patients. Only those having active sacroiliitis without signs of spondylitis were selected (number = seven patients) to receive fluoroscopic- guided local injection of 20 mg of infliximab in each SIJ. Leeds scoring system was used to score bone marrow edema (BME) representative of active inflammation. MRI of SIJ was repeated six months after the SIJ injection. Patients were clinically evaluated before, three and six months after SIJ injection. This included Bath Ankylosing Spondylitis Disease Activity index (BASDAI), Bath Ankylosing Spondylitis Functional index (BASFI) and Bath Ankylosing Spondylitis Global index (BASGI), back pain and back stiffness scores, in addition to measuring erythrocyte sedimentation rate (ESR).
Results There was a significant decrease in the mean levels of BASDAI, BASGI, back pain and stiffness scores (table) following local infliximab injection of SIJs. This improvement was detected after three months and was maintained at six months post injection. Furthermore, there was a decrease in the mean BME score, BASFI and ESR but without reaching statistical significance. BME scores decreased in five patients, increased in one patient and remained unchanged in another one, but none of them developed MRI signs of chronic sacroiliitis.
Conclusions Local infliximab injection of SIJ can be an effective therapeutic option in early axial SpA patients who failed to respond to NSAIDS. This modality can be considered in selected cases to avoid the high cost and side effects of systemically administered anti-TNF-α drugs. Longer period of follow up is needed to detect the maximum duration of disease improvement.
Disclosure of Interest None Declared