Graft-versus-host disease (GVHD) is a known complication of allogeneic bone marrow transplantation (ABMT) for hematological malignancies occurring in 33-64% of patients. However, little is known regarding neuromuscular complications of GVHD and their effect on treatment and survival outcomes.

To describe the neuromuscular complications of graft-versus-host disease.

We conducted a retrospective review of all patients seen at our institution with GVHD and concomitant neuromuscular complications between 2013 and 2018. Patients were excluded if their neuromuscular disorder preceded the diagnosis of GVHD or had an alternative identifiable etiology.

Among 688 patients with GVHD, 80 patients (11.6%) developed a new neuromuscular condition. However, only 20/688 patients (2.9%) had an immune-mediated neuromuscular disorder with no other identifiable etiology and were included in further analysis. Median age at onset of symptoms was 56 years (range 32-71) and 13 (65%) patients were male. The primary malignancy was acute leukemia in 12(60%), a lymphoproliferative disorders in 4(20%), a myelodysplastic syndrome in 3(15%) and a myeloproliferative neoplasm in 1 (5%) patient.  The neurological diagnosis was preceded by acute GVHD in 75% (n=15) and chronic GVHD in 65% (n=13) of patients. Median time from transplant to neurological diagnosis was 9 months (range 2-42). Reduced intensity conditioning with fludarabine based regimens were used in 17(85%) patients.

Immune-mediated myopathy was the most common complication (17 patients) manifesting with predominantly axial and/or proximal weakness. Eleven patients had a muscle biopsy showing: perimysial, mostly perivascular, inflammation in 6; dermatomyositis-like changes in 3 and endomysial inflammation in 2. Other immune-mediated complications consisted of Guillian-Barré syndrome (n=1), myasthenia gravis (n=1), and brachial plexitis (n=1).  

Immune-mediated neuromuscular complications occurred in 2.9% of our GVHD cohort with inflammatory myopathy being the most common. Treatment and survival outcomes will be presented at the time of the conference.