Severe deficiency of the specific von Willebrand factor-cleaving protease (ADAMTS 13) activity in a subgroup of children with atypical hemolytic uremic syndrome.
OBJECTIVE
The von Willebrand factor-cleaving protease (VWF-cp) activity has been reported to be deficient in adults with thrombotic thrombocytopenic purpura (TTP) and generally normal in adults with hemolytic uremic syndrome (HUS). The goal of this study was to determine VWF-cp activity in children with typical postdiarrheal (d+) HUS or atypical non-postdiarrheal (d-) HUS. Study design We measured VWF-cp activity in the plasma of 64 children with either (d+) HUS (n = 41) or (d-) HUS (n = 23).


RESULTS
In the acute phase of HUS, VWF-cp activity was normal (>50%) in 54 children and undetectable (<5%) in one (d+) HUS and in 6 (d-) HUS children. After a 3-month remission, the (d+) HUS patient recovered a 100% VWF-cp activity, and the 6 (d-) HUS patients kept an undetectable level. In these 6 (d-) HUS patients, the disease was characterized by a neonatal onset and several relapses (hemolytic anemia, thrombocytopenia, transient acute renal failure, cerebral ischemia), and sometimes the development of arterial hypertension or end stage renal failure.


CONCLUSIONS
A subgroup of pediatric patients with atypical (d-) HUS, with hematologic symptoms starting at birth and a recurrent course progressively involving kidney and brain, is related to VWF-cp deficiency and actually corresponds to Upshaw-Schulman syndrome revisited as congenital TTP.
Veyradier
Agnès
A
INSERM Unité 143, Le Kremlin Bicêtre, Service de Néphrologie, Hôpital Robert Debré, Tours, France.
Obert
Bernadette
B
Haddad
Elie
E
Cloarec
Sylvie
S
Nivet
Hubert
H
Foulard
Michel
M
Lesure
François
F
Delattre
Pierre
P
Lakhdari
Mustapha
M
Meyer
Dominique
D
Girma
Jean-Pierre
JP
Loirat
Chantal
C
Loriat
Chantal
C
D051722:ADAM Proteins; D000071120:ADAMTS13 Protein; D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D003289:Convalescence; D003968:Diarrhea, Infantile / Q000150:complications; D004927:Escherichia coli Infections / Q000150:complications; D019453:Escherichia coli O157; D005260:Female; D006463:Hemolytic-Uremic Syndrome / Q000097:blood* / Q000150:complications / Q000151:congenital / Q000628:therapy; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008666:Metalloendopeptidases / Q000172:deficiency* / Q000235:genetics; D010375:Pedigree; D014841:von Willebrand Factor / Q000235:genetics
D014841:von Willebrand Factor; D051722:ADAM Proteins; D008666:Metalloendopeptidases; D000071120:ADAMTS13 Protein; C099604:ADAMTS13 protein, human