In a group of schizophrenic patients the following parameters were inv
estigated: IgG, A, M. E. transferrin, alpha-1-antitrypsin, alpha-2-mac
roglobulin, complement activity of both the classical and alternative
pathway, C3 and C4 components of complement, anti- CMV antibodies, ant
i-deoxyribonucleoprotein antibodies and circulating immune complexes.
Spontaneous and PWM-induced IgG and IgM synthesis was also examined. A
n increase of serum IgG (18.2 g/l) was found in patients and unstimula
ted production of IgG was significantly increased compared with normal
control range (p<0.001). We observed higher unstimulated production o
f IgG compared with PWM stimulated production of IgG but not of IgM. O
ther parameters were not changed. After 6-week risperidone therapy the
re were significantly decreased IgG levels in the serum of schizophren
ic patients (p < 0.025). Spontaneous production remained increased com
pared with PWM stimulated production it was. however, lower than befor
e the therapy. After 24 weeks the levels of serum IgG and IgM were sig
nificantly reduced (p < 0.025). After long-term therapy the ratio betw
een unstimulated and PWM stimulated production of IgG was normalized a
nd the total amount of IgG produced was significantly lower (p<0.01) t
han that before the therapy. We conclude that schizophrenia is a disea
se with some immunological abnormalities and that long-term risperidon
e therapy has not an immunotoxic effect,.