Sporadic late-onset nemaline myopathy with MGUS: long-term follow-up after melphalan and SCT

Neurology. 2014 Dec 2;83(23):2133-9. doi: 10.1212/WNL.0000000000001047. Epub 2014 Nov 5.


Objective: Sporadic late-onset nemaline myopathy (SLONM) is a rare, late-onset myopathy that progresses subacutely. If associated with a monoclonal gammopathy of unknown significance (MGUS), the outcome is unfavorable: the majority of these patients die within 1 to 5 years of respiratory failure. This study aims to qualitatively assess the long-term treatment effect of high-dose melphalan (HDM) followed by autologous stem cell transplantation (SCT) in a series of 8 patients with SLONM-MGUS.

Methods: We performed a retrospective case series study (n = 8) on the long-term (1-8 years) treatment effect of HDM followed by autologous SCT (HDM-SCT) on survival, muscle strength, and functional capacities.

Results: Seven patients showed a lasting moderate-good clinical response, 2 of them after the second HDM-SCT. All of them had a complete, a very good partial, or a partial hematologic response. One patient showed no clinical or hematologic response and died.

Conclusions: This case series shows the positive effect of HDM-SCT in this rare disorder. Factors that may portend an unfavorable outcome are a long disease course before the hematologic treatment and a poor hematologic response. Age at onset, level and type of M protein (κ vs λ), and severity of muscle weakness were not associated with a specific outcome.

Classification of evidence: This study provides Class IV evidence that for patients with SLONM-MGUS, HDM-SCT increases the probability of survival and functional improvement.

MeSH terms

  • Adult
  • Age of Onset
  • Female
  • Follow-Up Studies
  • Humans
  • Male
  • Melphalan / administration & dosage
  • Melphalan / adverse effects*
  • Melphalan / therapeutic use*
  • Myopathies, Nemaline / complications
  • Myopathies, Nemaline / therapy*
  • Paraproteinemias / complications
  • Paraproteinemias / therapy*
  • Retrospective Studies
  • Stem Cell Transplantation*
  • Transplantation, Autologous / methods
  • Treatment Outcome


  • Melphalan