Please use this identifier to cite or link to this item: http://repositorio.unicamp.br/jspui/handle/REPOSIP/197622
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
Adult
Antibodies
Antigens, Human Platelet
Blood Platelets
Brazil
Female
Genotype
Hla Antigens
Humans
Infant, Newborn
Isoantibodies
Middle Aged
Mothers
Platelet Count
Prevalence
Prospective Studies
Risk Factors
Thrombocytopenia
Rights: fechado
Identifier DOI: 10.1111/j.1537-2995.2007.01064.x
Address: http://www.ncbi.nlm.nih.gov/pubmed/17207231
Date Issue: 2007
Appears in Collections:Unicamp - Artigos e Outros Documentos

Files in This Item:
File SizeFormat 
pmed_17207231.pdf152.55 kBAdobe PDFView/Open


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.