Immunological and electrophysiological investigations of severe ptosis after bone marrow transplantation.

Ocular problems are common in recipients of stem cell transplantation (SCT), but ptosis is rarely reported and investigated. Among 346 consecutive SCT recipients, severe bilateral ptosis was noticed or reported in six cases (five women and one man), all with acute graft-versus-host disease (aGVHD) and chronic graft-versus-host disease (cGVHD). On univariate analysis, both aGVHD (P=0.001) and cGVHD (P<0.001) were associated with post SCT ptosis, while a trend was shown for female sex (P=0.086). The median level of anti-acetylcholine receptor antibody was significantly higher in ptosis cases than controls with cGVHD (student's t-test, P=0.01). Antistriated muscle antibody was detected in three cases and was not significantly different from controls (Fisher's exact test, P=0.29). Tensilon tests were uniformly negative. However in five cases, single fibre electromyogram at frontalis muscle showed irregular recruitment effort, suggesting localized neuromuscular transmission defect reminiscent of ocular myasthenia gravis (MG). Two patients were observed, while three patients did not respond to mestinon or steroids treatment and one patient underwent aponeurosis advancement surgery. Transplant physicians and ophthalmologists should be aware of the problem of post SCT ptosis, which may be related to alloimmune causes of neuromuscular transmission block. Diagnosis can be difficult to confirm even with invasive SF-EMG testing. Most cases warrant conservative treatment due to chronicity, benign course and poor response to medication.