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

Abstract

We investigated polymorphonuclear leukocyte (PMN) function in a 50-year-old woman with primary Sjögren's syndrome (SS). The respiratory burst of PMN was monitored by luminol-enhanced chemiluminescence using zymosan, opsonized zymosan, zymosan-activated serum, and phorbol-myristate-acetate, as well as serial dilutions of aggregated immunoglobulin (aggIg) as Fc-receptor (FcR) stimulus. The effects of serum on the chemiluminescent response as well as the binding of aggIg to PMN were also compared. We found the patient's PMN not to respond to stimulation by aggIg, only the highest concentration (greater than 180 micrograms/ml) induced a marginal chemiluminescent response in the patient. By contrast, incubation of the patient's PMN with other stimuli resulted in responses similar to those in a healthy control. Binding of aggIg to PMN was higher in the patient (3.6% vs 1.5% of the radioactivity added in the control). Sera of patient and control induced similar chemiluminescence on PMN as did that of another human serum. Our data indicate a selective functional FcR defect of PMN despite unimpaired binding of aggIg in a patient with SS.

Fc‐Gamma receptor III shedding by polymorphonucIear cells in primary Sjögren's syndrome

“…In accord with earlier findings [l 11, there was an inverse correlation between the amount of these receptors in the serum and the proportion of FcyRIII-bearing PMN in the circulation. Schopf et al have also described a selective functional Fc receptor defect in a single SS patient [25]. Additional supportive data for our interpretation that serum FcyRIII originates from release by PMN, may be gathered, e.g.…”

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

“…The phagocytic uptake in this system is dependent on the Fc and C3b receptors of the cell, the major receptors promoting recognition, adherence, and, finally, internalisation of particles.26 Neutrophil phagocytosis measured by the uptake of latex particles has previously been reported to be normal in patients with Sjogren's syndrome,27 but Schopf et al suggested a selective functional Fc receptor defect in a single patient with primary Sjogren's syndrome. 28 An increased incidence of Fc receptor mediated phagocytosis has previously been seen in neutrophils from patients with rheumatoid arthritis2' and subjects prone to infection.29 In our consecutive series of unselected patients with primary Sjogren's syndrome we found that almost 40% (9/23) of them had recurrent bacterial infections, but they showed normal neutrophil phagocytosis. The initial step in the phagocytic process is the random migration of neutrophils-that is, the chemokinetic movement, to the site of infection or inflammation.…”