Platelet FcgammaRIIA receptor surface expression is increased in patients with ESRD and is associated with atherosclerotic cardiovascular events.
BACKGROUND
Accelerated atherogenesis is a prominent feature of end-stage renal disease (ESRD).


METHODS
Expression of platelet FcgammaRIIA immunoglobulin G receptor (FcgammaR) was measured in 2 populations: (1) 48 patients with ESRD with a mean age of 50.7 +/- 2.3 (SEM) years and (2) 48 healthy age- and sex-matched controls aged 53.6 +/- 1.6 years.


RESULTS
Platelet FcgammaR expression was enhanced significantly in patients with ESRD (mean fluorescence intensity [MFI], 7.88 +/- 0.42 [SEM]; 95% confidence interval [CI], 7.03 to 8.72 versus 5.07 +/- 0.21; 95% CI, 4.64 to 5.49; P < 0.0001). In patients with ESRD, multivariate analysis showed that hemoglobin level and diastolic blood pressure were related inversely to FCgammaR expression (P = 0.01 and P = 0.03, respectively). Atherosclerotic cardiovascular events (ACVEs) were recorded prospectively for the ESRD cohort. A total of 22 ACVEs, defined as the occurrence of myocardial infarction (10 events), cerebrovascular accident (7 events), and/or a peripheral vascular event (5 events), were observed. In the group with greater receptor expression (MFI > 7.785; n = 24), 13 of 17 patients (76.5%) experienced at least 1 ACVE, whereas only 4 of 17 patients (23.5%) with low FcgammaR expression (MFI < 7.785; n = 24) experienced an event (P = 0.007).


CONCLUSIONS
(1) Uremia is associated with enhanced platelet FcgammaR expression, and (2) patients with greater platelet FcgammaR expression are significantly more likely to experience ACVEs; however, (3) the small sample size is a limitation and our work therefore is a hypothesis-generating pilot study that remains to be confirmed.
El-Shahawy
Mohamed
M
Department of Medicine, Division of Nephrology, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA. elshahaw@usc.edu
Noureddin
Mazen
M
Abdullah
Hesham
H
Mack
Wendy J
WJ
Calverley
David C
DC
D000328:Adult; D015703:Antigens, CD / Q000096:biosynthesis*; D050197:Atherosclerosis / Q000150:complications / Q000378:metabolism*; D002318:Cardiovascular Diseases / Q000150:complications / Q000378:metabolism*; D006801:Humans; D007676:Kidney Failure, Chronic / Q000150:complications / Q000378:metabolism*; D008875:Middle Aged; D011446:Prospective Studies; D017452:Receptors, IgG / Q000096:biosynthesis*
D015703:Antigens, CD; C080568:Fc gamma receptor IIA; D017452:Receptors, IgG