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Type: Artigo de periódico
Title: A Prospective Study On The Prevalence And Risk Factors For Neonatal Thrombocytopenia And Platelet Alloimmunization Among 9332 Unselected Brazilian Newborns.
Author: Castro, Vagner
Kroll, Hartmut
Origa, Andréa F
Falconi, Mônica A
Marques, Sílvia B D
Marba, Sérgio T
Passini, Renato
Annichino-Bizzacchi, Joyce M
Costa, Fernando F
Santoso, Sentot
Arruda, Valder R
Abstract: Neonatal thrombocytopenia (NT) occurs in 0.5 to 0.9% of unselected Caucasian newborns. However, the prevalence of this complication in other populations is unknown. In this study the prevalence/causes of NT was determined in Brazilian newborns, a population characterized by admixture among Indigenous, Africans, and Caucasians. A prospective study was carried out in a 3-year period, to determine the prevalence and causes of thrombocytopenia in cord blood samples. Genotyping for HPA 1-5 systems was performed in pairs of mother/neonates with and without thrombocytopenia. All mothers with genotypic mismatches from each group were tested for HPA-specific antibody using the MAIPA technique to identify alloimmunization. Platelet counts <100 x 10(9)/L were detected in 1.5% of 9,332 unselected newborns. In 0.15%, platelet count was <50 x 10(9)/L. Clinically significant bleeding was rare. Underlying diseases were present in 48% of the thrombocytopenic cases. HPA 1-5 system genotype mismatches occurred in 50% of gestations, but did not predict the risk for thrombocytopenia. Notably, mismatched genotypes for HPA-5 were slightly increased in the thrombocytopenic group. The presence of anti-HPA-5b antibodies was observed in 0.05% of unselected pregnancies, but increased to 12% among mothers of neonates with thrombocytopenia and mismatched genotype (N = 51). Neonatal thrombocytopenia is common among Brazilian newborns at rates comparable with those described among Caucasians. These data suggest that screening for genotypic HPA mismatch, followed by an HPA-specific immunoassay system, particularly for the HPA-5 system, among mothers of newborns with thrombocytopenia in our population would allow the identification of pregnancies at risk of alloimmune thrombocytopenia.
Subject: Adolescent
Antigens, Human Platelet
Blood Platelets
Hla Antigens
Infant, Newborn
Middle Aged
Platelet Count
Prospective Studies
Risk Factors
Citation: Transfusion. v. 47, n. 1, p. 59-66, 2007-Jan.
Rights: fechado
Identifier DOI: 10.1111/j.1537-2995.2007.01064.x
Date Issue: 2007
Appears in Collections:Unicamp - Artigos e Outros Documentos

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