GRANULOCYTE DEFECTS AND OPIOID RECEPTORS IN CHRONIC EXPOSURE TO HEROIN OR METHADONE IN HUMANS

In order to elucidate better the immunological effect of opioid abuse in the absence of HIV infection as a confounding factor, granulocyte f unction was investigated in three groups of HIV-negative subjects, inc luding 20 active parenteral heroin abusers (H), 20 long-term methadone -maintained former opiate abusers (M) and 20 healthy controls (C). Che motaxis to N-formyl methionyl-leucyl-phenylalanine (fMLP), casein and activated plasma were markedly and similarly reduced (approx. 50%) in both H and M groups, as was true for superoxide production after fMLP and PMA stimulation, 47% decrease of C values. Polymorphonuclear (PMN) of H and M subjects also exhibited a very marked and similar reductio n in the expression of CD11b/CD18 integrin receptors after fMLP treatm ent, with values that were less than 10% of those in controls, as obse rved by now cytometry. In parallel, PMN of H and M individuals present ed an approximately four-fold increase in opioid receptors numbers com pared to controls, a significant inverse correlation existing between the increase in opiate receptors and defective chemotaxis. The possibl e mechanism underlying the observed changes in PMN of H and M individu als is discussed.