[Rheumatoid arthritis associated with microscopic polyangiitis]

Association of ANCA-associated vasculitis-rheumatoid arthritis overlap syndrome in four patients: rituximab may be the right choice?

OBJECTIVES

There have been few reports on the association of rheumatoid arthritis (RA) with anti-neutrophil cytoplasmic antigen (ANCA)-associated systemic vasculitides.

METHODS

Here we present four cases of RA overlapping with Wegener's granulomatosis (WG), microscopic polyangiitis (MPA) and Churg-Strauss syndrome (CSS). All these cases had both the diagnosis of RA and that of ANCA-associated vasculitis.

RESULTS

After we tried corticosteroids, multiple immunosuppressive drugs, sometimes plasmapheresis, rituximab was introduced to 3 out of 4 cases. Rituximab therapy was found to be effective in these three overlap cases. In the fourth case, rituximab was and will be considered; however, the patient has not given consent.

CONCLUSION

To our knowledge, this is the first report on RA+CSS association. Common pathogenic background, such as genetic predisposition and ANCA may account for the development of RA+vasculitis overlaps. In DMARD-refractory cases, such as the ones presented here, biologics, especially rituximab may be highly effective.