Abstract
Background B-cell depleting monoclonal antibodies are highly effective treatment for multiple sclerosis (MS) but have rarely been associated with seronegative arthritis. We report the findings in four cases of seronegative arthritis occurring in this context.
Methods Patients were identified from the Royal North Shore Hospital MS database and clinical and radiological data aggregated through review of the medical records.
Results Three female and one male patient were identified. The mean age was 49.5 years (SD 12) and MS disease duration, 17 years (SD 18). Two female patients had a prior diagnosis of mild to moderate psoriasis, one of whom had previously received treatment for psoriatic arthritis but was in remission. Two patients were treated with ocrelizumab and two with ofatumumumab. The median time to joint symptoms was 3.5 months (Range 1 to 12). All patients experienced increasing axial and limb joint pain, with two patients suffering disfigurement of joints. Three patients discontinued the anti-CD 20 and started an interleukin-
17a inhibitor which was effective for arthritis. One patient remained on ocrelizumab with Sulphasalazine added for arthritis. All 4 patients showed no evidence of disease activity (NEDA) over the ensuing 2-year follow-up.
Conclusion It is important to consider a history of psoriasis and seronegative spondyloarthritis prior to commencing B-cell depleting monoclonal antibodies in patients with multiple sclerosis, and to monitor for this rare complication. More data is required to determine optimal treatment strategies, particularly interleukin-17A inhibitors given their safety, and potential benefit, in MS.
