[The binding of 3H-spiperone to lymphocytes in patients with schizophrenia and first-degree relatives: in search of a genetic marker].

3H-spiperone binding of lymphocytes has been studied and proposed to be a useful vulnerability marker for certain subtypes of schizophrenia. The binding of 3H-spiperone into lymphocytes was studied in 22 schizophrenics, 19 unaffected relatives and 8 healthy subjects. Binding assay was performed, incubating lymphocytes with 0.04 to 0.4 mM of 3H-spiperone. Non-specific binding was measured with 10 mM haloperidol. At the end the lymphocytes were homogenized. The results show a significant (p < 0.01) lower affinity (high Kd values) in drug naive schizophrenics compared with the controls. No differences were found in the binding capacity (Bmax) of both schizophrenic groups compared with control subjects. The results cannot offer us a reliable biological marker for schizophrenia. The increase of the number of subjects is suggested.