Progressive Multifocal Leukoencephalopathy in Renal Transplant Recipients

Progressive multifocal leukoencephalopathy (PML), a slowly progressive papovavirus infection of the central nervous system (CNS), has been reported in more than 110 patients to date, over half of whom have had either leukemia or lymphoma.^1-13 Only occasionally has no obvious underlying immune-altering disorder been noted.^1,2 To our knowledge, only three patients have been reported previously to have developed PML after long-term immunosuppression for renal transplantation^5,12,13; the patient discussed here is the fourth. Our patient also demonstrated unilateral parkinsonian signs attributable to involvement of the extrapyramidal motor system. Parkinsonism has been a very unusual clinical manifestation of PML, and has been reported previously in only one patient.¹⁴ We believe that PML is emerging as a potentially serious problem in renal transplant recipients.

PATIENT SUMMARY  A 34-year-old man who had had multiple admissions for chronic renal failure and hypertension caused by chronic proliferative glomerulonephritis had both kidneys (and