Restorative effect of ofloxacin on inhibited chemiluminescence response of PMNs by sera from uraemic patients.

Abstract

Uraemic patients are thought to be susceptible to infection because of dysfunction of defence mechanisms, including polymorphonuclear leuco­ cytes (PMNs). The bactericidal effect of PMNs largely depends upon the production of reactive oxygen metabolites during the respiratory burst. Therefore, determination of the amount of reactive oxygen metabolites after stimulation by phorbol myristate acetate (PMA) is thought to be a useful method for investigating PMN function in patients undergoing haemodialysis. We previously reported that ofloxacin enhanced the luminol-dependent chemiluminescence (CL) response of PMNs, and an enhanced CL response was also observed under hyperosmotic conditions produced by high concentrations of urea and NaCl, in an in vitro model of renal medulla}l] In the pres­ ent study, we examined the effect of ofloxacin on the reduced CL response produced by sera of haemodialysis patients. Sera were obtained from 41 patients (32 males, 9 females) with renal failure. All were receiving long term haemodialysis. Sera from 21 healthy vol­ unteers were used as a control. PMNs were obtained from the peripheral blood of one healthy volunteer. Blood was collected in 3% citric acid and allowed to sediment in dextran for 1 hour. Each leucocyte­ rich supernatant was separated by centrifuga­ tion on Histopaque®. The luminol-dependent CL response was measured with a luminometer (Biolumat® model 9505, Berthold, Germany) after stimulation with PMA. The reaction mixture con­ sisted of 100111 of serum, 500111 of the cell suspen­ sion (2 x 106 cells/rnl), 2 x 10-6 mollL luminol, and 500111 PMA (2 x 10-3 mg/ml). The light reaction was traced for 30 minutes. The integral of the CL count was automatically calculated from the curve, and the CL response was expressed as log cpm, or as the percentage chemiluminescence compared