Asymmetric bilateral demyelinating optic neuropathy from tacrolimus toxicity.
OBJECTIVE
To report the first histopathologic description of optic nerve demyelination from tacrolimus (FK 506) toxicity in the absence of toxic levels of tacrolimus in a patient presenting with asymmetric bilateral visual loss after 5 years of tacrolimus therapy.


METHODS
We report a patient status post cardiac and renal transplantation who developed severe, progressive and asynchronous bilateral visual loss after prolonged treatment with tacrolimus. Orbital MRI showed an enlarged left optic nerve that enhanced with gadolinium.


CONCLUSIONS
After extensive negative work up, biopsy of one optic nerve was performed. Microscopic analysis showed extensive demyelination in the absence of vasculitis, neoplastic or infectious etiologies. Our patient illustrates that demyelination of the optic nerve causing asynchronous vision loss can be associated with tacrolimus toxicity in the absence of toxic drug levels.
Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA, USA.
Sriram
S
Venneti
Heather E
HE
Moss
Marc H
MH
Levin
M Reza
MR
Vagefi
Susan C
SC
Brozena
Amy A
AA
Pruitt
Zissimos
Z
Mourelatos
John Q
JQ
Trojanowski
Steven L
SL
Galetta
Laura J
LJ
Balcer
D001706:Biopsy; D003711:Demyelinating Diseases / Q000139:chemically induced*; D048909:Diabetes Complications; D018450:Disease Progression; D016027:Heart Transplantation; D006801:Humans; D007166:Immunosuppressive Agents / Q000009:adverse effects* / Q000097:blood; D016030:Kidney Transplantation; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009900:Optic Nerve / Q000473:pathology; D009901:Optic Nerve Diseases / Q000139:chemically induced*; D011183:Postoperative Complications / Q000139:chemically induced*; D012307:Risk Factors; D016559:Tacrolimus / Q000009:adverse effects* / Q000097:blood; D014792:Visual Acuity
D007166:Immunosuppressive Agents; D016559:Tacrolimus