Sir, We present the case of a patient with progressive multifocal leukoencephalopathy (PML), caused by the human polyoma virus JC, who was found to have a CD4+ count of 87 cells/mm3 and was subsequently diagnosed with idiopathic CD4+ lymphocytopenia (ICL). To our knowledge, this is the first reported case on the use of multiple agents targeted against both PML and ICL. A patient presented at an outside hospital with progressive right-sided weakness, numbness, mouth droop and speech loss. At that time, the patient was diagnosed with an ischaemic cerebrovascular accident and was started on appropriate therapy. Despite physical therapy, the patient continued to deteriorate and was re-evaluated after 2 months. Magnetic resonance imaging (MRI) at that time revealed progression of stroke or possible neoplasm, and extensive workup showed no evidence of vascular abnormality or CNS vasculitis. The patient had no risk factors for HIV infection and past medical history was unremarkable. The patient was transferred to our institution for further evaluation.

Upon admission, the patient presented with slurred speech, difficulty verbalizing their thoughts and right-sided weakness. Laboratory results included a normal white blood cell count, with normal neutrophil and slightly depressed lymphocyte counts. MRI revealed multiple white matter lesions throughout the brain, consistent with a demyelinating process. A brain biopsy confirmed characteristic findings of PML, with enlarged oligodendroglial nuclei and intranuclear ground glass-type inclusions. In situ hybridization for JC viral genome sequences was positive and the JC viral load was reported as 3600 copies/mL.