Hemolytic uremic syndrome in children: platelet aggregation and membrane glycoproteins.
OBJECTIVE
Several mechanisms have been proposed to explain the fibrin-platelet thrombosis at the microcirculation level in the different clinical conditions of hemolytic uremic syndrome (HUS). The relationships between platelet structure and function during the first 4 weeks of evolution of the disease were studied to understand the mechanism of platelet alteration.


METHODS
Coagulation parameters, platelet counts, and aggregation were studied in 49 children, and membrane glycoproteins (GPs) in 20 of the 49 children (mean age, 17 months) with HUS (Group 2) were studied during the first 4 weeks of evolution of the disease.


RESULTS
No disseminated intravascular coagulation was found in patients with recurrent or persistent thrombocytopenia. Platelet aggregation was sequentially performed during the first weeks of evolution. All patients had a functional decrease in the acute period of HUS. Platelet GPs GPIb, GPIIbIIIa, GPIIb, and GPIIIa were evaluated. GPIIbIIIa complex presented low level and never reached normal values during the first 4 weeks of disease.


CONCLUSIONS
Platelet alterations are probably caused by multiple mechanisms: "exhausted" platelets, structural membrane alterations caused by arginine-glycine-aspartic peptide blockade, or diminished or nonfunctional membrane GPIb and GPIIbIIIa complexes.
Sassetti
B
B
Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Argentina.
Vizcargüénaga
M I
MI
Zanaro
N L
NL
Silva
M V
MV
Kordich
L
L
Florentini
L
L
Diaz
M
M
Vitacco
M
M
Sanchez Avalos
J C
JC
D001427:Bacterial Toxins / Q000009:adverse effects; D001779:Blood Coagulation Factors / Q000032:analysis; D001798:Blood Proteins / Q000032:analysis; D002675:Child, Preschool; D003968:Diarrhea, Infantile / Q000150:complications; D004405:Dysentery, Bacillary / Q000150:complications; D004730:Endothelium, Vascular / Q000473:pathology; D004927:Escherichia coli Infections / Q000150:complications; D005260:Female; D006463:Hemolytic-Uremic Syndrome / Q000097:blood* / Q000503:physiopathology; D006801:Humans; D007223:Infant; D008297:Male; D008833:Microcirculation; D010974:Platelet Aggregation; D010976:Platelet Count; D010980:Platelet Membrane Glycoproteins / Q000172:deficiency*; D022622:Shiga Toxin 1; D013154:Spleen / Q000503:physiopathology; D019851:Thrombophilia / Q000209:etiology; D014281:Trihexosylceramides / Q000378:metabolism
D001427:Bacterial Toxins; D001779:Blood Coagulation Factors; D001798:Blood Proteins; D010980:Platelet Membrane Glycoproteins; D022622:Shiga Toxin 1; D014281:Trihexosylceramides; C018549:globotriaosylceramide