Estudo das frequências antigénicas dos sistemas sanguíneos ABO, rhesus É-MNS e da gestão das reservas de sangue no Hospital Central de Maputo

Abstract

This study was carried out from January to April 1999 at the Blood Bank of the Maputo Central Hospital (HCM), and aimed to determine the frequencies of ABO, Rhesus and MNS blood system antigens by race and by sex in Maputo; estimate the amount of blood used by each HCM ward; determine the amounts of blood reserves needed for rational and sustainable use; test the number of beds criterion established by the WHO to estimate the blood requirements of the HCM and relate the incidence of malaria with antigen frequency of the ABO and Rh blood systems. In order to determine the antigenic frequencies, blood samples were taken from 2000 donors and tested according to classical methods in force at the Blood Bank (BS). During three months, a daily survey of the blood needs of each ward was carried out. To determine the amounts of blood reserves for rational and sustainable use, the amounts of useful blood, blood supplied to wards and other hospitals for three months were surveyed and time series were made. The average value of the division between useful donations and the number of beds at the HCM was compared with the criteria established by the WHO. The antigen frequencies of 264 malaria patients were related to the control antigen frequencies of the BS blood donors. Most donors are male (85.2%) and a small part female (14.8%). Of the total 2000 blood donors, 57.5% belonged to group O; 22.2% to group A; 17.5% to group B and 3.0% to group AB. The most frequent antigens were c (98.3%), e (97.5%) and D (95.7%). There was no significant difference between sex and antigens. Significant differences were found between races and the C and c antigens of the Rh and S and s system of the MNS system. The ward that consumed the greatest amount of monthly blood was Obstetrics. The average monthly amounts of blood required for rational and sustainable use are approximately 840 ± 224 units of blood. There is a greater lack of blood in the BS between the months of September to January. The average amount of blood units per bed for the HCM was 7.6 ± 1.0. A relationship between the blood group frequencies of the ABO and Rh systems and the blood group frequency was not observed among patients with malaria. These results suggest the continuation of the study of frequencies for the other blood systems, as it would considerably increase the chances of studying the genotype and would solve problems in determining paternity. A socio-anthropological study to verify the causes of women's poor adherence to the act of donating blood. In times of greater blood shortages, campaigns to raise awareness of the population for this noble act of donating blood should be increased. (TRADUÇÃO NOSSA)