A research team led by a Johns Hopkins Childrens Center scientist has found the strongest evidence yet that a virus may contribute to some cases of schizophrenia.

In this weeks Proceedings of the National Academy of Sciences, Childrens Center neurovirologist Robert Yolken, M.D., and his colleagues report the molecular "footprint" of a retrovirus in the cerebrospinal fluid of about 30 percent of people with acute schizophrenia and about 7 percent of people with a chronic form of the disease. The footprint was absent in the brains and cerebrospinal fluid of all people who did not have schizophrenia.

"While a low level of retrovirus expression occurs in most human tissues, we found an unexpectedly high level of expression in the cerebrospinal fluids from individuals whod had a recent onset of schizophrenia," says Yolken, director of the Stanley Division of Developmental Neurovirology and a principal investigator in the research. "A significant portion of the people with schizophrenia in our study population had active expression of the retrovirus, whereas individuals without schizophrenia lacked the footprint."

The footprint is actually retroviral RNA created by the active expression of an endogenous retrovirus in the "W" family of endogenous retroviruses (HERV-W). Previous research by Yolken and others suggests activation of the viruses and the onset of certain forms of schizophrenia are caused by both genetic and environmental factors. This recent report identifies the HERV-W-like retrovirus as a prime candidate for the environmental component of some schizophrenia cases.

The researchers also examined brain tissue obtained postmortem from individuals with schizophrenia and from individuals who were normal or had a disorder other than schizophrenia.

Unlike HIV and other retroviruses, endogenous retroviruses are a natural part of the human genome, having inserted themselves into the human genome m
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Contact: David Bricker
dbricker@jhmi.edu
410-223-1728
Johns Hopkins Medical Institutions
9-Apr-2001