An in-vitro study of oral therapeutic doses of co-trimoxazole and erythromycin stearate on abnormal polymorphonuclear leucocyte migration.

The effects of administration for four days of co-trimoxazole (2 X 500 mg tablets daily) and erythromycin stearate (3 X 500 mg tablets daily) on persistently abnormal polymorphonuclear leucocyte (PMNL) migration in six individuals with a history of chronic or recurrent bacterial infections were studied. The effects of co-incubation of PMNL in vitro with both antimicrobial agents at concentrations of 12(-5) and 10(-4) M were also investigated. Two different leucoattractants were used, autologous serum activated with bacterial endotoxin (EAS) and the synthetic chemotactic tripeptide FMLP. In three homosexual males with the acquired immunodeficiency syndrome (AIDS) abnormal PMNL motility was associated with the presence of serum inhibitor(s) of cell migration. In a fourth female subject, with recurrent episodes of acute periodontitis, and intrinsic cellular defect of PMNL migration associated with markedly impaired FMLP-induced degranulation and binding to PMNL was observed. In the remaining two subjects with chronic osteomyelitis, the precise abnormality of PMNL movement was not defined but appeared to be of the cellular intrinsic type. Co-incubation of PMNL with erythromycin, but not cotrimoxazole, at both concentrations tested (10(-5) and 10(-4) M) significantly improved cell migration to EAS, Likewise administration of erythromycin, but not cotrimoxazole, significantly improved PMNL migration to EAS. Improvement or correction of abnormal PMNL motility during antimicrobial chemotherapy with erythromycin may be a useful property of this antimicrobial agent.