Tacrolimus Induced Leukoencephalopathy and Stroke-Like Symptoms: Case Report

Area of Science:

• Neuroscience
• Hematology
• Pharmacology

Background:

• Sickle cell disease (SCD) patients undergoing stem cell transplantation (SCT) require immunosuppression to prevent graft-versus-host disease (GVHD).
• Tacrolimus is a calcineurin inhibitor commonly used for GVHD prophylaxis, but it has a narrow therapeutic index and potential for neurotoxicity.

Observation:

• A 17-year-old female with SCD post-SCT presented with acute expressive aphasia, dysphagia, and drooling.
• Brain MRI demonstrated diffuse restricted diffusion in the corona radiata and white matter, consistent with toxic leukoencephalopathy.

Findings:

• The patient's tacrolimus serum concentration was elevated at 19.3 ng/mL (reference range 9-12 ng/mL).
• Discontinuation of tacrolimus led to rapid neurological improvement within 2 days, with serum levels decreasing to 8.2 ng/mL.

Implications:

• This case highlights tacrolimus-induced neurotoxicity as a critical complication in post-SCT patients.
• Close monitoring of tacrolimus levels and prompt recognition of neurological symptoms are essential for managing SCD patients after SCT.
• Alternative immunosuppressive agents, such as mycophenolate mofetil, can be considered for GVHD prophylaxis when neurotoxicity is suspected.