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Measurement of Factor V Activity in Human Plasma Using a Microplate Coagulation Assay
Published on: September 9, 2012
Inherited complete factor I deficiency associated with systemic lupus erythematosus, higher susceptibility to
N Amadei1, G V Baracho, V Nudelman
1Departamento de Imunologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, Brazil.
Abstract:
Here we describe two new cases of complete deficiency of factor I (fI) in two sisters from a consanguineous Brazilian family. The eldest sibling (20-year-old) developed systemic lupus erythematosus (SLE) early during childhood while the youngest had been committed on several occasions owing to repeated infections although she was asymptomatic for auto-immune diseases. We also detected lower concentrations of C3 and factor B in both sisters. Biological functions dependent on complement activation such as the production of opsonins and killing of phagocytozed micro-organisms, chemotactic factors and haemolytic activity were all significantly reduced in both probands. Consistent with the absence of fI and low levels of fH, a deregulated production of C3b was observed by bidimensional electrophoresis in sera of both the probands.
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