DEMONSTRATION OF IMMUNOGLOBULIN-G WITH AFFINITY FOR DOPAMINE IN CEREBROSPINAL-FLUID FROM PSYCHOTIC-PATIENTS

Using an enzyme-linked immunosorbent assay, significantly raised conce ntrations of immunoglobulin G with affinity for the neurotransmitter d opamine were demonstrated in cerebrospinal fluid from psychotic patien ts. We have varied the antigen presentation in order to find a conjuga te with low unspecific binding. The conjugation of dopamine to carbodi imide-activated poly-L-glutamic acid and that to activated succinimide ester of biotin are described. The use of glutaraldehyde conjugation is not recommended because of the risk of formation of tetrahydroisoqu inolines. A strong correlation (r = 0.94, P < 0.001) between the resul ts obtained with dopamine conjugated to poly-L-glutamic acid and dopam ine conjugated to biotin was observed. Forty-two human cerebrospinal f luid samples from 20 psychotic patients, (12 with a bipolar disorder a nd 8 with schizophrenia) and 22 control patients, with various neurolo gical diseases but no apparent psychiatric diseases were investigated. A significantly higher incidence (P < 0.001) of antibodies with affin ity for dopamine were found in the group of psychotic patients compare d with the neurological control group.