Progressive Multifocal Leukoencephalopathy with Negative XXXX PCR following Treatment of @entity706 : Implications for Biologics in the @entity7971 of Targeted @entity5 Therapy.

@entity1 @entity4653 @entity7971 @entity646 @entity706 @entity8315 @entity5 @entity645 @entity13332 @entity8775 @entity791 @entity912 @entity7578
Anticancer therapy predisposes @entity1 to infections by the immunosuppression that results from treatment. Although 85% of @entity1 with @entity7578 ( @entity7578 ) have concurrent @entity645 / @entity791 , @entity7578 can also develop in @entity1 after they receive chemotherapy for @entity5 . The case herein describes a 69-year-old @entity1 with history of @entity706 who presented with progressive @entity4653 and right-sided @entity912 . He received rituximab one year prior to presentation. PET scan suggested no recurrence of @entity706 . Cerebrospinal fluid (CSF) analysis was negative and showed fewer than 500   copies/mL of @entity8315 . However, brain biopsy showed chromatin margination and viropathic change within oligodendrocytes, confirming @entity7578 . He was started on @entity13332 and @entity8775 with some clinical improvement. To our knowledge, this is the first case of rituximab-associated @entity7578 in a @entity1 with negative @entity8315 PCR from the CSF. Recognition of @entity7578 in the differential of oncology @entity1 with CNS symptoms is an important consideration as we enter the @entity7971 of targeted therapy and personalized @entity5 medicine involving biologics. Furthermore, screening of @entity1 for presence of @entity646 prior to the use of biologics may be an important component of assessing @entity1 candidacy for these agents.
