Am J Psychiatry 1995; 152:1291-1297
Copyright © 1995 by American Psychiatric Association
Increases in CSF levels of interleukin-2 in schizophrenia: effects of recurrence of psychosis and medication status
CG McAllister, DP van Kammen, TJ Rehn, AL Miller, J Gurklis, ME Kelley, J Yao and JL Peters
Department of Psychiatry, University of Pittsburgh, PA 15213, USA.
OBJECTIVE: Interleukin-2, traditionally viewed as solely involved in
immunological events, has recently been shown to exert profound effects on
the development and regulation of the central nervous system. This study
examined the relationships between interleukin-2 in the CSF and plasma of
schizophrenic patients and clinical measures, including relapse and
medication status. Plasma and CSF interleukin-1 alpha levels were also
measured to ascertain the specificity of changes in cytokine levels.
METHODS: Seventy-nine physically healthy male patients with schizophrenia
(DSM-III-R) received diagnostic evaluation and behavioral ratings.
Haloperidol treatment was withdrawn for up to 6 weeks and patients were
evaluated for symptom recurrence. CSF and plasma were obtained by
established procedures before haloperidol withdrawal (N = 79) and after (N
= 64). RESULTS: CSF levels of interleukin-1 alpha decreased significantly
after haloperidol withdrawal but showed no relation to clinical status. In
contrast, levels of CSF interleukin-2 were associated with recurrence of
psychotic symptoms. Relapse-prone patients, examined both while medicated
and after drug withdrawal, had significantly higher levels of CSF
interleukin-2 than patients who did not relapse. CSF interleukin-2 level
during haloperidol treatment was a significant predictor of worsening in
psychosis. CONCLUSIONS: Levels of interleukin-2, a molecule that plays both
neurodevelopmental and neuroregulatory roles, may have a role in relapse in
schizophrenia. Levels of CSF interleukin- 2 appear to be affected by
relapse mechanisms, while peripheral blood levels are not. These changes
are specific to interleukin-2, since levels of interleukin-1 alpha were
affected by medication withdrawal but not by change in clinical state.
