An Unusual Case of Progressive Multifocal Leukoencephalopathy in a Patient with Non-traditional Risk Factors

Abstract

Progressive multifocal leukoencephalopathy (PML) is a frequently fatal demyelinating condition of the central nervous system in which reactivation of the human polyomavirus JC (JCV) leads to lytic infection of oligodendrocytes. JCV reactivation typically occurs in the setting of profound impairment of cellular immunity seen in conditions such as human immunodeficiency virus infection and acquired immune deficiency syndrome (HIV/AIDS), hematologic malignancies, autoimmune diseases, and treatment with immunosuppressive medications. However, an emerging body of literature suggests that minimal or occult immunosuppression may be sufficient for the development of PML in certain cases. We report the case of a 52 year old man diagnosed with PML without history of or risk factors for immunocompromise, with absolute number of CD4 + T cells below the lower limit of normal but not meeting criteria for idiopathic CD4+ lymphocytopenia (ICL), who was subsequently found to have evidence of hepatic cirrhosis of unclear etiology. This is only the eighth case published of hepatic cirrhosis as the main identifiable risk factor for the development of PML and informs the ongoing discussion on mechanisms of moderate immunocompromise sufficient to allow for occurrence of this disease.