Glomerular vascular cell adhesion molecule-1 expression in renal vasculitis.

AIMS: To study the expression of cell adhesion molecules in the renal biopsy specimens of patients with systemic vasculitis and Henoch-Schönlein purpura (HSP); to correlate this with the severity of glomerular inflammation. METHODS: Renal biopsy specimens obtained from eight patients with untreated systemic vasculitis (four with Wegener's granulomatosis and four with microscopic polyarteritis), eight with HSP and nine controls (four with normal histopathology and five with thin glomerular basement membrane disease) were stained using the alkaline phosphatase anti-alkaline phosphatase method with monoclonal antibodies directed against intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1) and E-selectin. RESULTS: Biopsy specimens of normal kidneys expressed ICAM-1 in glomerular endocapillary cells, Bowman's capsule epithelium, interstitial cells and interstitial vascular endothelium, and VCAM-1 in Bowman's capsule epithelium, proximal tubular epithelium and interstitial vascular endothelium. No staining with antibody directed against E-selectin was seen in any of the biopsy specimens. Biopsy specimens of patients with a vasculitic glomerulonephritis (segmental necrotising glomerulonephritis) expressed VCAM-1 in glomerular endocapillary cells (four of eight patients with systemic vasculitis; two of eight patients with HSP). In patients with a systemic vasculitis glomerular VCAM-1 expression was associated with a more severe renal lesoin (44, 50, 60, and 65% of glomeruli involved) than in those not showing glomerular VCAM-1 expression (3, 3, 11, and 39% of glomeruli involved). CONCLUSION: Expression of VCAM-1 by glomerular endocapillary cells in renal biopsy specimens raises the possibility that recruitment of VLA-4 bearing leucocytes may contribute to glomerular injury in Wegener's granulomatosis and microscopic polyarteritis.

Soluble circulating cell adhesion molecules in haemolytic uraemic 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, 14.5 x 10(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, 10.1 x 10(9)/l, range 4.3-26.5 10(9)/l vs. 4.3 10(9)/l, range 3.7-6.6 10(9)/l), 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+HUS 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 there 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 D+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.

Cytokines in haemolytic uraemic syndrome associated with verocytotoxin-producing Escherichia coli infection.

The proinflammatory cytokines tumour necrosis factor-alpha (TNF-alpha) interleukin (IL)-1 beta, IL-6, and IL-8 were measured in plasma and urine samples from 19 children with verocytotoxin-producing Escherichia coli (VTEC) induced haemolytic uraemic syndrome (HUS) and 30 controls. TNF-alpha was detected in the plasma of two cases and one control; IL-6 in the plasma of one, and the urine of two cases, and in the plasma of one control. IL-1 beta and IL-8 were each identified in eight of the 19 cases and in one and two controls respectively. Urinary IL-8 was found in seven cases, four of whom had plasma concentrations below the limit of detection suggesting renal secretion of this cytokine. Cytokine concentrations did not correlate with peripheral blood neutrophil count at onset of disease. These data confirm the systemic release of cytokines responsible for the coordination of acute inflammatory processes in some children with VTEC induced HUS.

Renal histopathology in fatal cases of diarrhoea-associated haemolytic uraemic syndrome. British Association for Paediatric Nephrology.

Autopsy material was examined from British children dying early in the course of haemolytic uraemic syndrome (HUS). These presented after 1983, the period in which verocytotoxin-producing Escherichia coli (VTEC) infection was confirmed as the leading cause of diarrhoea-associated (D+HUS) in the United Kingdom. Of 18 cases referred for this study, 3 were found on review to have no history of a diarrhoeal prodrome (D-HUS). In the D+ patients, the median duration from onset of diarrhoea to death was 8 days (range 4-42 days). VTEC infection was confirmed in 6 cases. All had neutrophilia at presentation (median 21, range 15-49.8 x 10(9)/l). The 15 cases had uniform pathological features, consisting of glomerular thromboses and congested rather than ischaemic glomeruli. Arteriolar thromboses were common at the hilum of glomeruli and were sometimes also seen proximally, including in interlobular arteries. There were cortical infarcts in 5 cases with extensive thrombosis. Cases were demonstrated to have significantly greater numbers of neutrophils expressed per 100 glomeruli than controls, when counted using immunohistological stains to neutrophil elastase and CD15. This study showed uniformity of the renal changes in D+HUS and gave further evidence of the importance of neutrophils in the pathogenesis of the disease.