ABSTRACT Background: We evaluated different technological approaches and anti-D clones to propose the most appropriate serologic strategy in detecting the largest numbers of D variants in blood donors. Methods: We selected 101 samples from Brazilian blood donors with different expressions of D in our donor routine. The tests were performed in immediate spin (IS) with eleven commercially available anti-D reagents in a tube and microplate. The D confirmatory tests for the presence of weak D included the indirect antiglobulin test (IAT) in a tube, gel and solid-phase red blood cell adherence (SPRCA). All DNA samples were extracted from peripheral blood and the D variants were classified using different molecular assays. Results: The RHD variants identified by molecular analysis included weak D types (1, 2, 3, 11 and 38) and partial Ds (DAR1.2, DAR1, DAR3.1, DAU0, DAU2, DAU4, DAU5, DAU6, DMH and DVII). The monoclonal-monoclonal blend RUM-1/MS26 was the best anti-D reagent used in detecting the D antigen in the IS phase in a tube, reacting with 83.2% of the D variants, while the anti-D blend D175 + 415 was the best monoclonal antibody (MoAb) used in a microplate to minimize the need for an IAT, reacting with 83.2% of the D variants. The D confirmatory tests using SPRCA showed a reactivity (3 - 4+) with 100% of the D variant samples tested. Conclusion: Our results show that, even using sensitive methods and MoAbs to ensure the accurate assignment of the D antigen, at least 17% of our donor samples need a confirmatory D test in order to avoid alloimmunization in D-negative patients.

OBJECTIVE: To evaluate the usefulness of DNA methods to provide a means to precisely genotypically match donor blood units for the antigen-negative type of 35 sickle cell disease patients<. METHODS: Red blood cell units were investigated for ABO, D, C, c, E, e, K, Fyª, Fy b, Jkª, Jk b, S, s, Diª and RH variants by performing a molecular array (Human Erythrocyte Antigen BeadChipTM, BioArray Solutions), polymerase chain reaction followed by restriction fragment length polymorphism analysis and sequencing of patient samples and donor units that had been serologically matched based on the ABO, Rh and K phenotypes and the presence of antibodies. RESULTS: Matches for 21 of 35 sickle cell disease patients presented discrepancies or mismatches for multiple antigens between the genotype profile and the antigen profile of their serologically-matched blood units. The main discrepancies or mismatches occurred in the RH, FY, JK and MNS systems. Eight Rh alloimmunized patients presented RHD and RHCE variants that had not been serologically identified. According to these results better matches were found for the patients with genotyped units and the patients benefited as shown by better in vivo red blood cell survival. CONCLUSION: Molecular matching is superior to serological matching in sickle cell disease patients, decreasing the risk of transfusion reactions, especially delayed transfusion reactions to existing alloantibodies and preventing alloimmunization.

OBJETIVO: Avaliar o desempenho da reação em cadeia da polimerase (PCR) em gel (convencional) como método diagnóstico não-invasivo para a genotipagem RHD fetal, por meio da análise do plasma materno. MÉTODOS: Foi conduzido um estudo de validação de teste diagnóstico a partir de 81 amostras sangüíneas obtidas de gestantes brasileiras RhD-negativo, entre 4 e 41 semanas de gestação. As regiões exon 10 e intron 4 do gene RHD foram testadas por meio da reação em cadeia da polimerase alelo-específica (AS-PCR) convencional. Os resultados da genotipagem fetal foram comparados com a tipagem sangüínea convencional no período neonatal. RESULTADOS: Quinze amostras foram obtidas no primeiro trimestre, 37 no segundo trimestre e 29 no terceiro trimestre. Houve falha de amplificação em 6 amostras. A concordância entre os resultados da genotipagem e da tipagem neonatal foi de 97,3%, sensibilidade de 98,3% e especificidade de 93,8%. CONCLUSÃO: AS-PCR convencional é um método com bom desempenho para a genotipagem RHD fetal por meio da análise do plasma materno, mesmo em uma população com alto grau de miscigenação.

OBJECTIVE: To establish the performance of conventional PCR as a noninvasive method for fetal genotyping, by free fetal DNA analysis of distinct RHD regions from maternal plasma, in a population of a diverse ethnic origin. METHODS: We conducted a validity of the diagnostic test by analyzing 81 plasma samples from RhD-negative Brazilian pregnant women, from 4 to 41 gestational weeks. We tested for exon 10 and intron 4 gene regions by allele specific-PCR. Fetal RHD genotyping by PCR on maternal plasma was compared to serologic RhD typing in the neonatal period. RESULTS: Samples were obtained as follows: 15 in the 1st, 37 in the 2nd and 29 in the 3rd trimester. General accuracy was 97.3%, sensitivity of 98.3% and specificity of 93.8%. CONCLUSIONS: Conventional PCR is an accurate method for fetal RHD genotyping on maternal plasma, even in a population of mixed ethnic origin.

A determinação dos fenótipos Rh, Kell, Duffy e Kidd, associada ao ABO é utilizada para prevenir a aloimunização a antígenos eritrocitários e participam também no processo de identificação de anticorpos nos pacientes com beta talassemia. Todavia, a fenotipagem desses pacientes é trabalhosa e de difícil interpretação. Nesta situação, deve ser avaliada uma alternativa ao teste de hemaglutinação para determinar o padrão antigênico dos pacientes. Utilizamos para tal fim o método PCR-RFLP. Foram preparados DNAs de 50 pacientes com beta talassemia que haviam sido anteriormente fenotipados pela hamglutinação e testados para Kell, Kidd, Duffy/GATA mutação por PCR-RFLP. RHD/não-D foi analisado pelo tamanho do produto, do PCR associado à seqüência do gene RHD no intron 4 e exon 10/3' UTR. Os testes de genotipagem foram realizados sem o conhecimento dos resultados dos fenótipos. Para os RHD/não-D, 47 foram RhD+ e RHD+/RHCE+, e 3 foram RhD- e RHD-/RHCE+. Para o Kell, 48 kk foram K2K2 e 2 Kk foram K1K2. Para o Duffy, das 44 amostras que haviam sido normais, GATA box, 8 Fy(a+b-) foram FYA/FYA, 15 Fy(a+b-) foram FYB/FYB e 19 Fy(a+b+) foram FYA/FYB; das outras 4 amostras, 3 foram FYA/FYB e heterozigoto GATA mutação, e 1 Fy(a-b-) era FYB/FYB, homozigoto GATA mutação. Duas amostras fenotipadas como Fy(a+b-), que eram normais GATA, apresentavam as mutações 265T/298A e 2 amostras fenotipadas como Fy(a-b+) haviam sido genotipadas como FYA/FYB. Para o Kidd, 15 Jk(a+b-) foram JKA/JKA, 12 Jk(a-b+) foram JKB/JKB, e 20 Jk(a+b+) foram JKA/JKB. Três amostras fenotipadas como JK(a+b+) haviam sido genotipadas como JKB/JKB. A genotipagem é mais acurada que a fenotipagem para determinação de grupos sangüíneos em pacientes portadores de beta talassemia politransfundidos. A genotipagem nesses pacientes pode ser importante para selecionar hemácias antigenicamente negativas para transfusão de glóbulos vermelhos.

Determination of Rh, Kell, Duffy and Kidd phenotypes in addition to ABO is used to prevent the alloimmunization to red blood cells (RBCs) antigens and as part of the antibody identification process in patients with beta Thalassemia. However, phenotyping in these patients can be time consuming and difficult to interpret. In these situations, it would be valuable to have an alternative to hemagglutination tests to determine the patient's antigen profile. We used PCR-RFLP to genotype such patients. DNA was prepared from 50 patients with beta Thalassemia who had been phenotyped by routine hemagglutination, and tested for Kell, Kidd, Duffy/GATA mutation by PCR-RFLP. RHD/non-D was analysed by PCR product size associated to RHD gene sequence in intron 4 and exon 10/3'UTR. The genotyping assays were performed without knowledge of phenotype results. For RHD/non-D, 47 were RhD+ and RHD+/RHCE+, and 3 were RhD- and RHD-/RHCE+. For Kell, 48 kk were K2K2 and 2 Kk were K1K2. For Duffy, of 44 samples that had normal GATA box, 8 Fy(a+b-) were FYA/FYA, 15 Fy(a+b+) were FYB/FYB, and 19 Fy(a+b+) were FYA/FYB; of the other 4 samples 3 were FYA/FYB and heterozygous GATA mutation, and 1 Fy(a-b-) was FYB/FYB, homozygous GATA mutation. Two samples phenotyped as Fy(a+b-) that had normal GATA , presented the 265T/298A mutations and two samples phenotyped as Fy(a-b+) were genotyped was FYA/FYB.. For Kidd , 15 Jk(a+b) were JKA/JKA, 12 Jk(a-b+) were JKB/JKB, and 20 Jk(a+b+) were JKA/JKB. Three samples phenotyped as JK(a+b+) were genotyped as JKB/JKB. Genotype is more accurate than phenotype for determination of blood groups in polytransfused patients with betaThalassemia. Genotyping in these patients can be helpful to select antigen-negative RBCs for transfusion.

Estudou-se soroprevalência anônima para Vírus de Imunodeficiência Humana (HIV) e sífilis através de coleta de sangue de cordão umbilical de 5.815 parturientes, em hospitais de Campinas, SP, por um período de seis meses. Foram utilizados testes de ELISA e "Western blot" para diagnóstico de infecção pelo HIV, e VDRL e TPHA para Treponema pallidum. Mantendo-se o anonimato, colheram-se informações sobre hospital de origem, dividido em universitário (público) e privado, forma de pagamento (seguro social, seguro particular e pagamento direto), idade, situação marital, escolaridade, ocupação e cidade de procedência. A soroprevalência para HIV foi 0,42 percent e para sífilis foi 1,16 percent. Foi encontrada associação entre ambas, isto é, maior prevalência da primeira nas amostras positivas para lues (p=0,02). Após análise por regressão logística, apenas o hospital universitário mostrou-se associado à soropositividade para HIV, e a mesma variável e maiores idades se relacionaram à sífilis. Todas as reações positivas para HIV foram encontradas em hospitais universitários ou em pacientes cujos partos foram pagos pelo SUS em hospitais privados. Concluiu-se que a prevalência de infecção pelo HIV está se aproximando daquela encontrada através de sorologia para sífilis, afetando pacientes de camadas socioeconômicas menos favorecidas. Sugere-se considerar a indicação de sorologia rotineira e consentida para HIV no pré-natal, quando a população mostrar prevalência de infecção próxima ou maior que 1 percent.

The anonymous seroprevalence of HIV and syphilis was studied by collecting umbilical cord blood samples from 5,815 women who gave birth in Campinas' hospitals throughout a six-month period. ELISA and Western blot were used for HIV, and VDRL and TPHA for Treponema pallidum screening. While maintaining the anonymity of the women, information was recorded on the hospital of origin, divided into university (public) and private hospitals, as well as on the form of payment (social security, private insurance or direct payment), age, marital status, education, employment and place of residence. Seroprevalence was 0.42 percent for HIV and 1.16 percent for syphilis. There was a significant correlation between a positive reaction to the two infections (p=0.02). After univariate and logistic regression analysis, only university hospitals were shown to be associated with seropositivity for HIV, whereas the same variable and an older age were associated with syphilis. All positive reactions were found either in public hospitals or among social security patients treated at private institutions. The conclusion was that HIV infection is becoming almost as prevalent as syphilis among this population, and affects primarily the lower socio-economic strata. This suggests that routine, voluntary HIV serology should be considered and discussed with patients during prenatal or delivery care whenever a population shows a seroprevalence close to or greater than 1 percent.