JC Virus In Patients Research Articles

Subclinical central nervous system infection with JC virus in patients with AIDS.

Immunocompromised patients, particularly those with AIDS, develop progressive multifocal leukoencephalopathy (PML) due to central nervous system infection with JC virus (JCV). It is unknown whether JCV infection in the central nervous system can occur in the absence of PML symptoms. To address this question, autopsy specimens from patients with AIDS were examined. The brains of a group of patients without AIDS or central nervous system disease were also examined. JCV DNA was detected by the polymerase chain reaction in brain tissue from 4 (31%) of 13 human immunodeficiency virus (HIV)-positive patients. JCV was also detected in 1 elderly HIV-negative patient but not in the 11 other control brains. JCV was not detected in 22 myocardial specimens obtained at autopsy from HIV-negative patients nor 10 peripheral blood specimens from HIV-positive patients. The presence of JCV in brains of patients without clinically evident PML suggests that JCV may be present in the central nervous system without clinical disease.

Progressive multifocal leukoencephalopathy (PML): in vitro cell-mediated immune responses to mitogens and JC virus.

Cell-mediated immunity was studied by in vitro tests in seven patients with progressive multifocal leukoencephalopathy (PML). Lymphocyte proliferation in response to mitogenic stimulation was reduced to a variable degree in all patients, indicating a general impairment of cell-mediated immune responsiveness, although mitogen-induced production of the lymphokine migration inhibitory factor (LIF) was normal in most cases. Cell-mediated immunity to JC virus (JCV) was assessed by LIF production in response to JCV antigen. In the six PML patients tested, LIF production with JCV antigen was absent despite the presence of antibody to JCV in serum. This contrasted with positive LIF production in seropositive normal individuals and patients and patients with other diseases. These results provide the first in vitro evidence of a depressed cell-mediated immune response to JCV in patients with PML, and support the hypothesis that PML is accompanied by a selective marked deficiency in cellular response to this virus in association with a general depression of cell-mediated immunity of variable severity.