Polymyositis-related chronic graft-versus-host disease

In September 2018, findings from reported cases in graft-versus-host-disease (GvHD) associated polymyositis (PM) were published in Clinical Case reports. The authors aimed to review data from two reports of polymyositis-related GvHD in order to better understand this rare complication of allogeneic hematopoietic stem cell transplantations (allo-HSCT).

Case 1

• 48-year-old woman with acute myeloid leukemia (AML), diagnosis in 2013
• Complete remission (CR) after two courses of chemotherapy
• The patient underwent allo-HSCT in February 2014 after reduced intensity conditioning
• New symptoms after 10 months: limb weakness and mild dyspnea after walking without myalgia, skin rash, or obvious dysphagia

Case 2

• 31-year-old woman with AML, diagnosis 20 months ago
• CR was achieved with two courses of chemotherapy
• Allo-HSCT after fifteen months after reduced intensity conditioning
• Hospitalization because of limb weakness and myalgia for 5 months

Test results for Patients 1 and 2 (data is given as Patient 1 and 2)

• CK (U/L): 2118 vs 18
• Lactate dehydrogenase (U/L): 528 vs 241
• Aspartate aminotransferase (U/L): 89 vs 192
• Alanine aminotransferase (U/L): 85 vs 137
• Myoglobin (ng/mL): 1057.90 vs3
• CRP (mg/L): 0.2 vs6
• Antinuclear antibodies: 1:100 vs 1:320
• Myositis autoantibody: negative in both patients
• Thyroid glands: negative in both patients

Therapy

• Patient 1
  • increased dosage of prednisone and cyclosporin A (CsA), but no significant result was seen
  • rituximab (100 mg) plus a low dose of intravenous immunoglobulin (IVIG, 5-10 g) weekly was applied for consecutive 6 weeks
  • the patient’s CK level became normal
• Patient 2
  • oral prednisone and CsA did not improve the patient’s status
  • tacrolimus (3 mg QD) combined with oral methylprednisolone (40 mg QD) was implemented
  • Patient 2 had been followed up for over 1 year and she is in a good condition receiving tacrolimus at 3 mg with methylprednisolone at 12 mg daily

In summary, these case reports show that patients who underwent allo-HSCT can develop T cell-mediated immunologic muscle disorder which is similar to polymyositis with comparable clinical manifestations. Corticosteroids and immunosuppressants are feasible therapy options.