Não comparecimento de doadores inaptos sorológicos para repetição dos testes: o que fazer?: [carta ao editor] / Nonappearance of ineligible blood donors for follow-up testing: what should be done?: [letter to editor]

In Brazil, the use of confirmatory or complementary tests isoptional for blood banks; however it is their responsibility tocontact donors with reagent tests and refer them to appropriateservices to confirm diagnosis and for treatment. In the UberabaBlood Bank (Hemominas), all donors with positive results forserological screening tests are requested, by mail, to return andrepeat the tests. In a study at this blood bank, it was noted that alarge percentage of donors with reagent serology for hepatitis Cin the first analysis (23.3%) did not return to the service for repeattests. Among the donors that did not return for repeat tests, weobserved a significantly higher number of first-time donors(p=0.0039), under 30-year-old (p=0.0327) and single individuals(p=0.0062) and those who do not live in the city (p=0.0465). Nodifferences were found comparing gender and skin color. As thecontact letter does not explain why donors are asked to return fortests, the donors are unaware of the results of examinations. Thus,if they donate blood in other blood banks, they really are infectedwith the hepatitis C virus and if failure in serologic screeningoccurs, there is a possibility of disease transmission if. So whatcan be done to increase the return rate for repeat tests? We believean urgent review of the methods used to contact these donors isnecessary, which will provide better and earlier therapy to infectedindividuals and help to reduce the risk of spread of infection.

Importância dos testes sorológicos de triagem e confirmatórios na detecção de doadores de sangue infectados pelo vírus da hepatite C / Importance of screening and confirmatory tests to detect blood donors infected by the hepatitis C virus

A triagem sorológica de doadores de sangue com baixos índices de prevalência de infecção, como no caso da hepatite C (HCV), gera um percentual considerável de resultados falso-positivos e descarte de bolsas de hemocomponentes freqüentemente não infectados. O objetivo deste estudo foi pesquisar o perfil sorológico e, com base no teste confirmatório, a ocorrência de hepatite C nos doadores com sorologia positiva ou indeterminada do Hemocentro Regional de Uberaba (HRU). Os testes confirmatórios foram realizados por meio da detecção do RNA do HCV no plasma, utilizando-se o método RT-PCR qualitativa. Foram realizadas, no período de 1992 a 2005, 171.027 doações de sangue no HRU, sendo 24,3 por cento de doadores iniciais e 75,7 por cento de retorno. O índice de inaptidão para HCV foi de 0,3 por cento (561 doações), sendo que 53,0 por cento destas eram de doadores iniciais e 47,0 por cento de retorno, com prevalências de 0,5 por cento e 0,2 por cento, respectivamente (p<0,0001). O índice de reações inconclusivas foi significativamente maior nos doadores de retorno (p=0,0214). Noventa e oito candidatos foram submetidos à PCR qualitativa e apenas 34 (34,7 por cento) apresentaram resultados positivos, com índice de positividade significativamente menor nos doadores de retorno (p=0,0184) e quase três vezes menor nos inconclusivos. Assim, verificamos que grande número de doadores, tanto anti-HCV positivos quanto indeterminados, não tiveram confirmada a presença da infecção pelo HCV, levando-nos a concluir que a inaptidão sorológica para hepatite C no HRU, na maioria das vezes, não correspondeu à presença de infecção viral no doador.

Serological screening of blood donors with low indexes of infection, including hepatitis C virus (HCV), accounts for a substantial percentage of false-positive results with consequent loss of non-infected blood components. The aim of this study was to evaluate the occurrence of hepatitis C using confirmatory tests for blood donors with positive or inconclusive results at Hemocentro Regional de Uberaba (HRU). Confirmatory tests were performed by the detection of HCV RNA in plasma using qualitative RT-PCR. The study was carried out from 1992 to 2005 for 171,027 blood donors, 24.3 percent first-time and 75.7 percent repeat donors. The ineligibility rate to HCV was 0.3 percent (561 donors) with 52.9 percent of them being first-time donors and 47.0 percent repeat donors with prevalences of 0.5 percent and 0.2 percent respectively (p<0.0001). The rate of inconclusive results was significantly higher among repeat donors (p=0.0214). Ninety-eight samples were subjected to qualitative PCR and only 34.7 percent (34) had positive results, with a significantly lower rate of positiveness for repeat donors (p = 0.0184) and almost a threefold lower rate of inconclusive results for the same donors. These results showed that, for a large number of donors with positive and inconclusive tests for anti-HCV, the infection was not confirmed. We concluded that serological ineligibility for hepatitis C of donors at HRU was not always associated with the presence of viral infection.