Immune-mediated necrotising myopathy associated with antibodies to the signal recognition particle treated with a combination of rituximab and cyclophosphamide

BMJ Case Rep. 2015 Aug 3:2015:bcr2014206250. doi: 10.1136/bcr-2014-206250.

Abstract

A 50-year-old man presented with dysphagia and proximal muscle weakness. He was diagnosed with immune-mediated necrotising myopathy associated with antibodies to the signal recognition particle. After an initial response following treatment with high-dose steroids, intravenous immunoglobulin and methotrexate, there was a relapse of the immune condition. The clinical deterioration occurred less than 2 months after disease onset. The refractoriness of this disease was characterised by an increase of the already severe muscle wasting that led to respiratory failure and progressive dysphagia, regardless of the immunosuppressant treatment. At this time the patient was referred to our department. He was restarted on intravenous pulses of methylprednisolone associated with intravenous cyclophosphamide, but with no effect. After 3 weeks, rituximab was started with a dramatic and progressive improvement. There were no complications associated with rituximab/cyclophosphamide treatment and the disease has been kept in remission, for the last 3 years.

Publication types

  • Case Reports

MeSH terms

  • Autoantibodies / blood*
  • Autoimmune Diseases / blood
  • Autoimmune Diseases / drug therapy*
  • Autoimmune Diseases / pathology
  • Cyclophosphamide / therapeutic use*
  • Drug Therapy, Combination
  • Glucocorticoids / therapeutic use
  • Humans
  • Immunoglobulins / therapeutic use
  • Immunologic Factors / therapeutic use
  • Immunosuppressive Agents / therapeutic use*
  • Male
  • Methylprednisolone / therapeutic use
  • Middle Aged
  • Muscle Weakness / blood
  • Muscle Weakness / drug therapy
  • Muscle Weakness / immunology
  • Muscle Weakness / pathology
  • Muscular Diseases / blood
  • Muscular Diseases / drug therapy
  • Muscular Diseases / immunology*
  • Muscular Diseases / pathology
  • Necrosis
  • Rituximab / therapeutic use*
  • Signal Recognition Particle / immunology*

Substances

  • Autoantibodies
  • Glucocorticoids
  • Immunoglobulins
  • Immunologic Factors
  • Immunosuppressive Agents
  • Signal Recognition Particle
  • Rituximab
  • Cyclophosphamide
  • Methylprednisolone