1. Complement genetic variants and FH desialylation in S. pneumoniae-Haemolytic Uraemic Syndrome
- Author
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Instituto de Salud Carlos III, European Commission, Comunidad de Madrid, Fundación Senefro, Ministry of Human Capacities (Hungary), Semmelweis University, Hungarian Academy of Sciences, Gómez Delgado, Irene [0000-0002-9734-8788], Corvillo, Fernando [0000-0001-6418-5647], Nozal, Pilar [0000-0002-8981-4312], Arjona, Emilia [0000-0002-0753-3657], Madrid, Álvaro [0000-0002-5942-8488], Melgosa, Marta [0000-0001-6236-414X], Csuka, Dorottya [0000-0003-3610-9852], Veszeli, Nóra [0000-0002-7647-2173], Prohászka, Zoltán [0000-0003-1761-7982], Sánchez-Corral, Pilar [0000-0003-4212-1233], Gómez Delgado, Irene, Corvillo, Fernando, Nozal, Pilar, Arjona, Emilia, Madrid, Álvaro, Melgosa, Marta, Bravo, Juan, Szilágyi, Ágnes, Csuka, Dorottya, Veszeli, Nóra, Prohászka, Zoltán, Sánchez-Corral, Pilar, Instituto de Salud Carlos III, European Commission, Comunidad de Madrid, Fundación Senefro, Ministry of Human Capacities (Hungary), Semmelweis University, Hungarian Academy of Sciences, Gómez Delgado, Irene [0000-0002-9734-8788], Corvillo, Fernando [0000-0001-6418-5647], Nozal, Pilar [0000-0002-8981-4312], Arjona, Emilia [0000-0002-0753-3657], Madrid, Álvaro [0000-0002-5942-8488], Melgosa, Marta [0000-0001-6236-414X], Csuka, Dorottya [0000-0003-3610-9852], Veszeli, Nóra [0000-0002-7647-2173], Prohászka, Zoltán [0000-0003-1761-7982], Sánchez-Corral, Pilar [0000-0003-4212-1233], Gómez Delgado, Irene, Corvillo, Fernando, Nozal, Pilar, Arjona, Emilia, Madrid, Álvaro, Melgosa, Marta, Bravo, Juan, Szilágyi, Ágnes, Csuka, Dorottya, Veszeli, Nóra, Prohászka, Zoltán, and Sánchez-Corral, Pilar
- Abstract
Haemolytic Uraemic Syndrome associated with Streptococcus pneumoniae infections (SP-HUS) is a clinically well-known entity that generally affects infants, and could have a worse prognosis than HUS associated to E. coli infections. It has been assumed that complement genetic variants associated with primary atypical HUS cases (aHUS) do not contribute to SP-HUS, which is solely attributed to the action of the pneumococcal neuraminidase on the host cellular surfaces. We previously identified complement pathogenic variants and risk polymorphisms in a few Hungarian SP-HUS patients, and have now extended these studies to a cohort of 13 Spanish SP-HUS patients. Five patients presented rare complement variants of unknown significance, but the frequency of the risk haplotypes in the CFH-CFHR3-CFHR1 region was similar to the observed in aHUS. Moreover, we observed desialylation of Factor H (FH) and the FH-Related proteins in plasma samples from 2 Spanish and 4 Hungarian SP-HUS patients. To analyze the functional relevance of this finding, we compared the ability of native and “in vitro” desialylated FH in: (a) binding to C3b-coated microtiter plates; (b) proteolysis of fluid-phase and surface-bound C3b by Factor I; (c) dissociation of surface bound-C3bBb convertase; (d) haemolytic assays on sheep erythrocytes. We found that desialylated FH had reduced capacity to control complement activation on sheep erythrocytes, suggesting a role for FH sialic acids on binding to cellular surfaces. We conclude that aHUS-risk variants in the CFH-CFHR3-CFHR1 region could also contribute to disease-predisposition to SP-HUS, and that transient desialylation of complement FH by the pneumococcal neuraminidase may have a role in disease pathogenesis.
- Published
- 2021