title: Activation of the alternative pathway of complement during the acute phase of typical haemolytic uraemic syndrome.
abstract: Haemolytic uraemic syndrome (HUS) is characterized by haemolytic anaemia, thrombocytopenia and acute renal failure. We studied the activation state of classical and alternative pathways of complement during the acute phase of Shiga toxin-associated HUS by performing a prospective study of 18 patients and 17 age-matched healthy controls to evaluate C3, C3c, C4, C4d, Bb and SC5b-9 levels. SC5b-9 levels were increased significantly in all patients at admission compared to healthy and end-stage renal disease controls, but were significantly higher in patients presenting with oliguria compared to those with preserved diuresis. C3 and C4 levels were elevated significantly at admission in the non-oliguric group when compared to controls. No significant differences were found for C4d values, whereas factor Bb was elevated in all patients and significantly higher in oliguric patients when compared to both controls and non-oliguric individuals. A positive and significant association was detected when Bb formation was plotted as a function of plasma SC5b-9 at admission. Bb levels declined rapidly during the first week, with values not significantly different from controls by days 3 and 5 for non-oligurics and oligurics, respectively. Our data demonstrate the activation of the alternative pathway of complement during the acute phase of Stx-associated HUS. This finding suggests that complement activation may represent an important trigger for the cell damage that occurs during the syndrome.
authors: Pediatric Nephrology Service, Hospital Italiano.|Department of Pediatrics, School of Medicine, University of Buenos Aires.
authors: J R
authors: JR
authors: Ferraris
authors: Pediatric Nephrology Service, Hospital Italiano.
authors: V
authors: V
authors: Ferraris
authors: Pharmacology Unit, School of Dentistry, University of Buenos Aires.|Institute for Biomedical Research (INBIOMED), School of Medicine, University of Buenos Aires and National Scientific and Technical Research Council.
authors: A B
authors: AB
authors: Acquier
authors: Central Laboratory, Hospital Italiano.
authors: P B
authors: PB
authors: Sorroche
authors: Central Laboratory, Hospital Italiano.
authors: M S
authors: MS
authors: Saez
authors: Immunology Service, Hospital de Niños Ricardo Gutierrez, Buenos Aires, Argentina.
authors: A
authors: A
authors: Ginaca
authors: Pharmacology Unit, School of Dentistry, University of Buenos Aires.|Institute for Biomedical Research (INBIOMED), School of Medicine, University of Buenos Aires and National Scientific and Technical Research Council.
authors: C F
authors: CF
authors: Mendez
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D003167:Complement Activation / Q000276:immunology*; D003176:Complement C3 / Q000276:immunology; D050578:Complement C3-C5 Convertases, Alternative Pathway / Q000276:immunology*; D015932:Complement C3c / Q000276:immunology; D003181:Complement C4 / Q000276:immunology; D015935:Complement C4b / Q000276:immunology; D015938:Complement Membrane Attack Complex / Q000276:immunology*; D005260:Female; D006463:Hemolytic-Uremic Syndrome / Q000276:immunology*; D006801:Humans; D007668:Kidney / Q000276:immunology / Q000473:pathology; D008297:Male; D008875:Middle Aged; D010446:Peptide Fragments / Q000097:blood / Q000276:immunology; D011446:Prospective Studies; D022621:Shiga Toxin / Q000276:immunology; D055815:Young Adult
chemical_list: D003176:Complement C3; D003181:Complement C4; D015938:Complement Membrane Attack Complex; D010446:Peptide Fragments; C047610:SC5b-9 protein complex; D022621:Shiga Toxin; D015932:Complement C3c; D015935:Complement C4b; C032261:complement C4d; D050578:Complement C3-C5 Convertases, Alternative Pathway
keywords: HUS; acute renal injury; alternative pathway; complement