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PCR detection of JC virus DNA in brain tissue from patients with and without progressive multifocal
P Ferrante1, R Caldarelli-Stefano, E Omodeo-Zorini
1Institute of Medical Microbiology, University of Milan, Italy.
Abstract:
Progressive multifocal leukoencephalopathy (PML) is a demyelinating disease of the central nervous system, which is thought to be a result of the reactivation of JC virus (JCV), a human polyomavirus. The disease occurs in individuals with immunosuppression and in recent years there has been an increase in PML cases due to AIDS. A nested polymerase chain reaction (n-PCR) was employed to detect JCV and BK virus (BKV) DNA in brain tissue collected postmortem from 28 AIDS patients with PML and from 13 patients without PML, but with other diagnoses, including solid tumors, Alzheimer's disease, thromboembolism, myocardial infarction and acute cerebrovascular diseases. All 28 brain specimens from the patients with PML were positive for JCV DNA when tested by n-PCR and three of the latter were also positive for BKV DNA. These results were confirmed by an enzyme restriction analysis and a DNA hybridization assay. Interestingly, in this study, JCV DNA was also found in 6 brain tissue specimens from 4 subjects with diseases unrelated to PML or AIDS. All the brain specimens from the control group were negative for BKV DNA. The results confirm that the n-PCR is a useful tool for PML diagnosis. The presence of JCV DNA in the brain tissue of patients without PML is particularly important since it indicates that JCV could be latent in the brains of immunocompetent individuals. Moreover, detection of simultaneous presence of JCV and BKV in the brain tissue of the patients with PML demonstrates that BKV may also infect the human brain without causing any apparent neurological disease.
Insights
JC virus (JCV) DNA was detected in brain tissue of AIDS patients with progressive multifocal leukoencephalopathy (PML). JCV DNA was also found in individuals without PML, suggesting latency in immunocompetent hosts.
Area of Science:
- Neurovirology
- Molecular Biology
- Immunology
Background:
- Progressive multifocal leukoencephalopathy (PML) is a severe demyelinating disease of the central nervous system.
- PML is caused by the reactivation of the human polyomavirus, JC virus (JCV).
- Increased PML cases are observed in individuals with acquired immunodeficiency syndrome (AIDS) due to immunosuppression.
Purpose of the Study:
- To detect JC virus (JCV) and BK virus (BKV) DNA in postmortem brain tissue.
- To evaluate the utility of nested polymerase chain reaction (n-PCR) for PML diagnosis.
- To investigate the presence of JCV and BKV in patients with and without PML, including those with AIDS.
Main Methods:
- Nested polymerase chain reaction (n-PCR) was used to detect JCV and BKV DNA.
- Brain tissue samples were collected postmortem from 28 AIDS patients with PML and 13 control patients.
- Results were confirmed using enzyme restriction analysis and DNA hybridization assays.
Main Results:
- All 28 PML brain specimens tested positive for JCV DNA.
- Three PML specimens also tested positive for BKV DNA.
- JCV DNA was detected in 6 brain specimens from 4 individuals without PML, indicating potential latency.
Conclusions:
- Nested PCR is a valuable diagnostic tool for PML.
- JCV DNA can be present in the brain tissue of immunocompetent individuals, suggesting latent infection.
- BK virus (BKV) can co-infect the brain with JCV in PML patients without causing apparent neurological disease.