Fc and complement receptor integrity of polymorphonuclear (PMN) cells following thermal injury

In patients sustaining thermal injury, a sequential study was formulated to evaluate Fc and complement receptor expression of polymorphonuclear cells (PMN). Additionally, the role of factors in burn sera and maturity of PMN cells in the circulation were studied. The salient features of the study were: Marked reduction in Fc receptor expression by the 5th day of injury in both survivors and non-survivors. Thereafter levels gradually increased in survivors, though they were still below the normal range. In non-survivors, the depression was severe and persistent. In contrast to Fc receptor expression, complement receptor integrity was not grossly affected in both survivors and non-survivors. Burn sera collected from survivors on the 5th and 13th post-burn day showed reduction in Fc receptor expression of normal PMN cells, whereas sera obtained a month after the injury exhibited no inhibitory effect. Non-survivors sera inhibited Fc receptor expression of normal PMN cells on 5th, 13th and 21st post-burn days. The appearance, increase and disappearance of immature PMN cells in the circulation was correlated with the clinical progress of the patient. Mechanisms involved in the aberrations and its implications are discussed.