In vivo fixation of immune complexes on polymorphonuclear cells and release of neutrophil cationic proteins in systemic lupus erythematosus (SLE).

Neutrophils (PMN) appear to be involved in inflammatory phenomena as a result of direct interaction with immune complexes (IC). In SLE glomerulonephritis IC are fixed in vivo on the PMN surface through the receptors for FC fragments of complexed immunoglobulins and complement. Phagocytic properties are lost and immunological lysosomal release in vitro is markedly reduced by virtue of receptor occupation. The elimination of neutrophil cationic proteins (NCP) in urine is an expression of PMN lysosomal constituent release.