DOES
BORNA DISEASE VIRUS CAUSE NEUROPSYCHIATRIC DISORDERS?
K. Bechter, S.
Herzog, R. Schò
ttler. Dept. Psychiatry II University of Ulm,
Germany.
Borna diseases (BD) with
its typical clinical course in horses and sheep is
restricted to Germany, Switzerland and Austria. However,
antibodies against Borna disease virus (BDV) can be detected
worldwide. A role of BDV in psychiatric disorders, especially
depression has been suggested (since 1985). Recently, there are
controversies about the meaning and validity of studies showing
BDV-RNA in PBMCs of 50% of depressed patients and in the
brains of patients with various psychiatric disorders.
We have continuously performed
seroepidemiologic studies in psychiatric, neurologic and surgical
patients (n–15.000) over 13 years, and have controlled
the sensitivity and specificity of serological methods by studies
of horses with natural BD (>100): Comparing the results from
serological investigations of sera and CSFs with the post
mortem diagnosis taken out with different methods (histology,
immunohistology, virus isolation, western blot), we found high
specificity and sensitivity of our serological methods (Herzog et
al, 1994).
In our human studies, we found an
increased BDV seroprevalence in psychiatric patients and a
slightly increased BDV seroprevalence in neurological patients.
An analysis of age-related dynamics of BDV seroprevalence in the
populations investigated showed that the increase of BDV
seroprevalence was due nearly exclusively from an increase in
young psychiatric patients (17 30 years), ages when
psychiatric disorders frequently begin. In MRI investigations we
found more frequently slight brain atrophy in BDV seropositive
patients. Most important, in about 25% of acutely diseased
BDV-seropositive psychiatric patients suffering from
schizophrenic or affective psychoses, we found pathologic
increases of BDV-specific IgG in the cerebrospinal fluids (CSF),
indicating an active although slight BDV encephalitis underlying
the respective psychosis. In one such case we recently introduced
cerebrospinal fluid filtration (CSFF) in psychiatric therapy; the
patient improved significantly, explained by removing toxic
factors during CSFF from the CSF, which were similar to that fund
earlier in neurological patients with CNS inflammatory diseases,
e.g. Guillain-Barré syndrome (GBS). CSFF had a lasting positive
effect in the schizophrenic patient similar to experiences with
CSFF in GBS. Therefore CSFF may have impact for more curative
treatments in psychiatry.