Functional Fc-receptor defect of polymorphonuclear leukocytes in a patient with Sjögren's syndrome

Fc-gamma receptor III shedding by polymorphonuclear cells in primary Sjögren's syndrome

A sandwich enzyme-linked immunosorbent assay was developed to assess Fc-gamma receptor III (Fc gamma RIII), based on a combination of two non-competing monoclonal antibodies. This receptor was detectable in the serum of eight out of 23 patients with primary Sjögren's syndrome and two out of 23 normal controls. The proportion of Fc gamma RIII-carrying polymorphonuclear (PMN) cells was lower (P < 0.05) in the patients with cell-free Fc gamma RIII (90.4 +/- 7.5%) than in the remainder (84.8 +/- 8.3%). The PMN cell functions were evaluated and the diminished adherence (71.7, geometric mean) and chemotaxis (1.23) paralleled the Fc gamma RIII release. The relative inefficiency of PMN cells in SS might be due to phagocytosis of immune complexes.

Neutrophil function in patients with primary Sjögren's syndrome: relation to infection propensity

The function of neutrophils was studied in 23 consecutive patients with primary Sjögren's syndrome and in 35 healthy controls. Nineteen patients (83%) had extraglandular symptoms and nine patients (39%) had recurrent bacterial infections. The patients had a marked reduction of neutrophil adherence, especially those with recurrent bacterial infections, and reduced opsonic activity of plasma. Increased random migration of isolated neutrophils was found in the patients with a propensity for bacterial infections. Chemotaxis and chemokinesis, phagocytosis, chemiluminescence production, and the intracellular neutrophil contents of lactoferrin and lysozyme were normal. The various aspects of neutrophil function tested in this study were not related to disease duration or to inflammatory disease activity. The impaired neutrophil adherence may play a part in the increased propensity for bacterial infections seen in patients with primary Sjögren's syndrome.