B-cell targeted therapy alone may not be effective in bullous pemphigoid

Abstract

Conflict of interest: none declared. We report a 77‐year‐old man who was diagnosed in 1996 as having bullous pemphigoid (BP). Direct immunofluorescence showed bright linear basement‐membrane zone (BMZ) staining with IgG and C3, and indirect immunofluorescence (IIF) showed circulating IgG BMZ antibodies to a titre of 1 : 640 with split‐skin staining only on the roof. Clinically, his blisters were controlled with high‐dose prednisolone. Various steroid‐sparing agents were used, including azathioprine, dapsone, oxytetracycline, minocycline, mycophenolate mofetil, sulfamethoxypyridazine, intravenous immunoglobulins, chlorambucil and ciclosporin. Of these drugs, only ciclosporin appeared to be effective in controlling the patient's BP. He experienced treatment‐related side‐effects including severe nausea with azathioprine, nausea and haemolytic anaemia with dapsone, nausea with oxytetracycline, a skin eruption with mycophenolate mofetil, aseptic meningitis and retinal branch vein thrombosis with intravenous immunoglobulins, thrombocytopenia with chlorambucil, and renal impairment with ciclosporin, and these therapies were eventually stopped because of the side‐effects. As a consequence of the high‐dose steroids, the patient developed significant proximal myopathy, osteoporosis, cataracts and recurrent cellulitis. About 18 months after his ciclosporin was discontinued, he received a trial of rituximab (375 mg/m2), a chimeric monoclonal antibody against CD20 on B lymphocytes.1 He received two doses of rituximab 4 weeks apart (Table 1).