We were interested in the report by Pollmächer and colleagues indicating that sIL-2R concentrations may be influenced by smoking. The effects of smoking on sIL-2R concentrations have been previously reported in patients without schizophrenia, but Pollmächer and colleagues suggest that this effect is also found in patients with schizophrenia. Given the high prevalence of smoking among patients with schizophrenia, this is an important observation and suggests that several previous reports
*Data are given as the mean±SD. about increased sIL-2Rs in association with schizophrenia1-3 may need to be reanalyzed if smoking data are available for those subjects.
Decreased IL-2 production has also been consistently reported in patients with schizophrenia by several groups,4-8 but smoking status has not been taken into account in those studies either. Pollmächer and colleagues question whether decreased IL-2 production might also be associated with smoking rather than with schizophrenia, and we would like to respond