Fetal RHD Genotyping by Analysis of Maternal Plasma in a Mixed Population

Autor(es)

Amaral, Daphne R. T. ^[1] ; Credidio, Debora C. ^[1] ; Pellegrino, Jr., Jordao ^[1] ; Castilho, Lilian ^[1]

Afiliação do(s) autor(es)

^[1] Univ Estadual Campinas, Hemoctr, BR-13081970 Campinas, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: JOURNAL OF CLINICAL LABORATORY ANALYSIS; v. 25, n. 2, p. 100-104, 2011.
• Citações Web of Science: 9

Resumo

Background: Maternal plasma analysis for the determination of the fetal RHD status is an exciting tool for the management of RhD-negative pregnant women, specially sensitized women. We assessed the accuracy of fetal RHD genotyping by analysis of maternal plasma in a multi-ethnic population. Methods: We analyzed plasma samples from 88 RhD-negative pregnant women between 11 and 39 weeks of gestation, median age of 28 years old to determine the fetal RHD genotype. This population was from Southeastern Brazil with high mixed ethnic background. Fourteen patients (16%) had anti-D alloantibody. We used Taqman primers and probes to detect by real-time PCR, exons 4, 5, and 10 of RHD. As internal controls we used primers/probes sets to SRY and CCR5. Peripheral or umbilical cord bloods from respective nenonates were collected during delivery and hemagglutination was performed. Results: Fifty-eight samples (66%) were genotyped as RHD+, 27 samples (31%) showed complete absence of RHD and 3 samples (3%) presented a D variant (RHD psi). All the results agreed with the neonatal typing, including the three fetuses with the RHD psi, phenotyped as RhD-negative. Thus, the accuracy of the fetal RHD genotyping in this mixed population was 100%. The earliest pregnancy in which fetal RHD was detected was 11 weeks. Conclusion: Our findings indicate that the accuracy of RHD gene using three regions (exons 4, 5, and 10) can be sufficient for clinical application in a multi-ethnic population. This knowledge helped us on the development of a feasible protocol for fetal RHD genotyping on DNA from maternal plasma for our population. J. Clin. Lab. Anal. 25:100-104, 2011. (C) 2011 Wiley-Liss, Inc. (AU)

• Processo FAPESP: 09/05924-0 - Análise de polimorfismos e expressão de antígenos de grupos sanguíneos: implicações clínicas
• Beneficiário: Lilian Maria de Castilho
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 07/07151-3 - Determinação do genótipo rhd fetal através do plasma materno pela técnica de pcr em tempo real
• Beneficiário: Daphne Renata Tavares Amaral
• Modalidade de apoio: Bolsas no Brasil - Mestrado