SOLUBLE CIRCULATING CELL-ADHESION MOLECULES IN HEMOLYTIC-UREMIC SYNDROME

Plasma concentrations of soluble vascular cell adhesion molecule-1 (sVCAM-1), E-selectin (sE-selectin) and intercellular adhesion molecule-1 (sICAM-1) were measured by enzyme-linked immunosorbent assay in four groups of children. Group 1 consisted of 20 patients with acute diarrhoea-associated haemolytic uraemic syndrome (D+HUS), the aetiology of HUS being verocytotoxin-producing Escherichia coli infection in each case. Controls consisted of 11 patients who had previously had D+HUS (group 2), 12 with chronic renal failure (group 3) and 8 healthy controls (group 4). When compared with healthy controls, the acute D+HUS group had higher sVCAM-1 (median 1,875 ng/ml, range 1,200-6,450 ng/ml vs. 1,200 ng/ml, range 975-2,125 ng/ml), von Willebrand factor antigen, (1.9 U/ml, range 0.85-5.1 U/ml vs. 0.55 U/ml, range 0.3-1.57 U/ml), white cell count (WBC, 14.5x10(9)/l, range 7.8-43.1 10(9)/l vs. 8.9 10(9)/l, range 5.7-10.8 10(9)/l) and neutrophil count (PMN, 10.1x10(9)/l, range 4.3-26.5 10(9)/l vs. 4.3 10(9)/l, range all P<0.005, and sICAM-1 was reduced (230 ng/ml, range 130-340 ng/ml vs. 400 ng/ml, range 260-690 ng/ml), P<0.05. Within the acute D+KUS group there was a significant correlation between sICAM-1 and PMN (r=0.56, P<0.01). There was no correlation between any adhesion molecule and plasma creatinine or von Willebrand factor. Comparing the acute HUS group with children with chronic renal failure, WBC (P<0.001), PMN (P<0.01) and sVCAM-1 (P<0.01) were significantly elevated, but then was no difference between the von Willebrand factor (P=0.08) or the sICAM-1 (P>0.1). sVCAM-1 is elevated and sICAM-1 decreased in acute DI-HUS. This pattern of altered adhesion molecule concentration is unlike that in adults with vasculitis and suggests that different endothelial regulatory factors are at play.