Circulating endothelial cells as a prognostic marker in thrombotic microangiopathy.
BACKGROUND
Circulating endothelial cells (CECs) are a reliable marker of disease activity in a variety of vascular disorders. Damage to microvascular endothelial cells is a hallmark of thrombotic microangiopathy (TMA). The aim of this study is to identify and count CECs during the course of TMA and evaluate whether cell numbers may serve as a prognostic marker in patients undergoing plasma exchange.


METHODS
Fifteen patients (8 women, 7 men) aged 31 to 66 years with TMA of different causes were studied before and after 4 sessions of plasma exchange. CECs were isolated by using anti-CD146-driven immunomagnetic isolation and counted after staining with Ulex Europaeus lectin-1.


RESULTS
Numbers of CECs were markedly elevated in all patients before treatment (64 to 672 CEC/mL; mean, 320 +/- 205 CEC/mL) compared with healthy controls (0 to 16 CEC/mL; mean, 6.4 +/- 4.2 CEC/mL; P < 0.001). Patients with a favorable outcome had significantly greater initial CEC levels (mean, 426 +/- 175 CEC/mL; P < 0.001), and cell numbers decreased significantly after 4 treatments of plasma exchange (mean, 101 +/- 53 CEC/mL; P = 0.001). Patients with disease unresponsive to plasma exchange presented with lower initial CEC levels (mean, 108 +/- 36 CEC/mL), and numbers failed to decrease after plasma exchange (mean, 114 +/- 57 CEC/mL; P = 0.827).


CONCLUSIONS
Markedly elevated numbers of CECs reflect severe and widespread endothelial damage in patients with TMA. Cell numbers at presentation and their degree of decrease after 4 sessions of plasma exchange could provide important prognostic clues.
Erdbruegger
Uta
U
Department of Medicine, Division of Nephrology, Hannover Medical School, Hannover, Germany. erdbruegger.uta@mh-hannover.de
Woywodt
Alexander
A
Kirsch
Torsten
T
Haller
Hermann
H
Haubitz
Marion
M
D000328:Adult; D000368:Aged; D000743:Anemia, Hemolytic / Q000097:blood* / Q000175:diagnosis / Q000473:pathology / Q000503:physiopathology; D015415:Biomarkers / Q000097:blood; D042783:Endothelial Cells / Q000473:pathology*; D005260:Female; D006801:Humans; D008297:Male; D008833:Microcirculation / Q000473:pathology; D008875:Middle Aged; D010974:Platelet Aggregation / Q000502:physiology; D011379:Prognosis; D013921:Thrombocytopenia / Q000175:diagnosis / Q000473:pathology / Q000503:physiopathology; D013927:Thrombosis / Q000097:blood* / Q000175:diagnosis / Q000473:pathology* / Q000503:physiopathology
D015415:Biomarkers