Detection of Retroviral RNA in the CSF of Individuals with Schizophrenia





H. Karlsson*,

F. Leister, J Schroder, S. Bachmann, E.F. Torrey and R.H. Yolken

The Stanley

Division of Developmental Neurovirology, Johns Hopkins University

School of Medicine, 600 N. Wolfe St./Blalock 1111, Baltimore, MD

21287-4933, USA.

We have explored the hypothesis

of retroviral involvement in the etiology of schizophrenia by

testing 18 CSF’s obtained from first-episode individuals

with schizophrenia-spectrum disorder and 18 CSF’s from

individuals without psychiatric disease.

RNA’s were isolated from

pelleted CSF’s, reverse transcribed, and subjected to PCR

using primers directed towards a conserved region of the

retroviral pol-gene (Tuke et al, Acta Neurol. Scand. 1997.


A PCR-product was detected in

seven of the 18 schizophrenia samples and in three of the 18

control samples. Subsequent cloning and sequencing of these

products showed that at least six samples from the individuals

with schizophrenia contained a single retroviral species, showing

90-95% homology to the multiple sclerosis associated retrovirus

(Perron et al, PNAS 1997. 94:7583-7588). Individual control

samples were found to contain multiple species, homologous to

human endogenous retroviral sequences (including multiple

sclerosis associated retrovirus), probably originating from

contaminating human nucleic acids.

These results document the

presence of specific retroviral particles in the CSF of acutely

ill individuals with schizophrenia. The retroviral particles may

have arisen from the differential activation of endogenous

sequences or may be the result of exogenous retroviral infection.