Rituximab in the Treatment of Refractory Dermatomyositis

Abstract

Dermatomyositis is an inflammatory myopathy characterized by muscle weakness and inflammation. In contrast to polymyositis and inclusion body myositis, humoral immune mechanisms appear to contribute to the pathogenesis of dermatomyositis. A 56-year-old man with dermatomyositis resistant to conventional therapies was treated with 6 weekly infusions of the anti-CD-20 monoclonal antibody, rituximab, at a dosage of 100 mg/m in addition to other agents. The patient demonstrated a remarkable clinical response as indicated by an increase in muscle strength and a decline in creatine kinase enzymes. B-cell depletion therapy with rituximab used alone or in combination with other immunosuppressive therapies may be a viable option in patients with dermatomyositis as well as other autoimmune diseases refractory to current therapies.

Experiencia con rituximab en miopatía inflamatoria idiopática refractaria

“…Existen diversos trabajos publicados en la actualidad -comunicación, serie de casos y un ensayo clínico piloto-, en los que se describe los beneficios obtenidos con rituximab, todos ellos en pacientes con MII refractarios al tratamiento convencional (8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18) y existiendo un solo artículo donde fue indicado como de primera línea (19) . Las evaluaciones de respuesta han sido referidas al compromiso cutáneo, niveles de enzimas musculares, fuerza muscular proximal medida por medio de la ponderación del clínico o a través de algún instrumento de medición, recuento de linfocitos CD20+; así mismo, se ha venido considerando el tiempo en el que fue necesario brindar nuevamente el fár-maco, basado en la reactivación de la enfermedad.…”

Long-term remission of severe refractory dermatopolymyositis with a weekly-scheme of immunoglobulin followed by rituximab therapy

“…There are encouraging results in individual case reports and small series on the use of rituximab for the treatment of severe and refractory DM/PM, similarly as its effects on other immune-based diseases, whose mechanism of action is not completely understood [4,5]. Although rare, adverse effects are an important concern of the treatment with rituximab, such as the potentially severe infusion-related reactions and the occurrence of opportunistic infections, malignancy and activation of latent viral infections [10], among others [11].…”

Immunotherapies for Immune-Mediated Myopathies: A Current Perspective

“…There have also been many positive reports on the efficacy of rituximab in treatment-resistant DM [63][64][65][66][67]. These early reports led to an open-label study of rituximab for refractory PM [68].…”