von Willebrand factor-cleaving protease in childhood diarrhoea-associated haemolytic uraemic syndrome.
A deficiency of von Willebrand factor (vWF)-cleaving protease, either due to a congenital deficiency or to the presence of a protease inhibitor of vWF-cleaving protease has been associated with thrombotic thrombocytopenic purpura (TTP). We have studied vWF-cleaving protease in diarrhoea-associated haemolytic uraemic syndrome (D+ HUS), which shares clinical features with TTP. 29 children with acute D+ HUS and 13 control children were studied. vWF-cleaving protease activity was normal (range 50-150%) in 39 of 42 plasma samples. Levels of protease activity between 25 and 50% were noted in plasma from two D+ HUS patients. One D+HUS patient, who had clinical features of TTP, had a vWF-cleaving protease inhibitor producing a severe deficiency of vWF-cleaving protease. Thus a deficiency of vWF-cleaving protease appears to be atypical in D+HUS. The detection of a vWF-cleaving protease inhibitor in one patient suggests it may be associated with infection such as E. coli O157.
Hunt
B J
BJ
Department of Haematology, Guy's and St Thomas' Trust, London, UK. beverley.hunt@gstt.sthames.nhs.uk
Lämmle
B
B
Nevard
C H
CH
Haycock
G B
GB
Furlan
M
M
D051722:ADAM Proteins; D000071120:ADAMTS13 Protein; D000293:Adolescent; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D003967:Diarrhea / Q000201:enzymology* / Q000209:etiology / Q000382:microbiology; D004927:Escherichia coli Infections / Q000097:blood; D006463:Hemolytic-Uremic Syndrome / Q000150:complications / Q000201:enzymology* / Q000209:etiology / Q000382:microbiology; D006801:Humans; D007223:Infant; D008666:Metalloendopeptidases / Q000037:antagonists & inhibitors / Q000097:blood* / Q000172:deficiency; D011480:Protease Inhibitors / Q000009:adverse effects / Q000097:blood; D011696:Purpura, Thrombocytopenic / Q000201:enzymology / Q000209:etiology
D011480:Protease Inhibitors; D051722:ADAM Proteins; D008666:Metalloendopeptidases; D000071120:ADAMTS13 Protein; C099604:ADAMTS13 protein, human