HETEROGENEITY OF NEUTROPHIL ANTIBODIES IN PATIENTS WITH PRIMARY SJOGRENS-SYNDROME

Our aims were to determine the prevalence of neutrophil antibodies in patients with primary Sjogren's syndrome (pSS), identify their target antigen(s), and evaluate their functional significance, Neutrophil ant ibodies were detected using an indirect immunofluorescence (IIF) test and an enzyme-linked immunosorbent assay (ELISA), using recombinant hu man Fc-gamma receptor (Fc gamma RIIIb) as a capture agent, Luminol-dep endent chemiluminescence was then measured by an established technique , Antibodies to neutrophils were detected in 30 of 66 patients (45%) a nd categorized on the basis of positivity for the two assays: IIF+/ELI SA+ (group A: five patients), IIF+/ELISA- (group B: five patients), an d IFF-/ELISA+ (group C: 20 patients). All positive sera contained anti bodies directed to the neutrophil-specific Fc gamma RIIIb, and none of them bound to NA(null) neutrophils. The titer of neutrophil-reactive antibodies (groups A and B) showed no correlation with the neutrophil count, but these autoantibodies did reduce the cell ability to generat e a respiratory burst, Thus, neutrophil antibodies are common in patie nts with pSS. Their main target appears to be Fc gamma RIII, and this may partly account for the dysfunction in Fc gamma R-mediated clearanc e by the reticuloendothelial system reported in these patients. (C) 19 95 by The American Society of Hematology.