Aloimunização

Abstract

Revisão ResumoAloimunização é a formação de anticorpos quando há a exposição do indivíduo a antígenos não próprios, como ocorre, por exemplo, na transfusão de sangue incompatível e nas gestantes, cujos fetos expressam em suas células sanguíneas antígenos exclusivamente de origem paterna. Este artigo se restringe à aloimunização contra antígenos eritrocitários em pacientes obstétricas. Quase todos os anticorpos antieritrocitários podem ser enquadrados em um dos 29 sistemas de grupos sanguíneos já reconhecidos, sendo os mais comumente implicados na doença hemolítica perinatal o anti-D, anti-c e anti-Kell, seguidos por anti-C, anti-E, anti e, anti-Fyª e anti-Jkª. A pesquisa de anticorpos irregulares permite o diagnóstico de indivíduos aloimunizados e modernas técnicas genéticas têm melhor caracterizado estas pacientes para a profilaxia e segmento pré-natal. O tradicional acompanhamento das gestações de risco para a doença hemolítica perinatal, com a espectrofotometria do líquido amniótico e a transfusão intraperitoneal, vem rapidamente sendo substituído pela doplervelocimetria na artéria cerebral média e a transfusão intravascular guiada por ultrassonografia em tempo real. É possível também citar como avanços melhorias nos materiais e na qualidade do sangue transfundido, que, em conjunto, têm elevado a sobrevivência de fetos acometidos. Indubitavelmente, a correta aplicação da profilaxia com uso do anti-D é exitosa com potencial para reduzir os casos de aloimunização. AbstractAlloimmunization is the formation of antibodies when there is an exposition of the individual to non-self antigens, as it occurs, for example, in the transfusion of incompatible blood and pregnancies, in whom the fetus express in its sanguineous cells antigens exclusively of paternal origin. This article is restricted to the alloimmunization against erythrocytes antigens in obstetric patients. Almost all the anti-erythrocytes antibodies can be fit in one of the 29 systems of already recognized sanguineous groups, being more implied in the hemolytic disease of the newborn anti-D, anti-c and anti-Kell, followed by anti-C, anti-E, anti e, anti-Fyª and anti-Jkª. The research of irregular antibodies, to permit the diagnosis of alloimmunizated people, and the modern genetic techniques have better characterized these patients for the prophylaxis and prenatal segment. The traditional accompaniment of the gestations of risk for hemolytic disease of the newborn, with the spectral analysis of the amniotic liquid and the intraperitoneal transfusion, has being quickly substituted for the Doppler ultrasound evaluation in the middle cerebral artery, the intravascular transfusion guided for ultrasonography in real time, beyond improvements in the materials and the quality of the blood, that in set, have raised the survival of the attempting fetus. Doubtlessly, the correct application of the prophylaxis with use of anti-D is successful with potential to reduce the alloimmunization cases.

Efficacy of Hematological Indices for β Thalassemia Trait Screening in Pregnant Women

“…It is one of most common inherited single gene disorder [9,10]. Different ß thalassemia carrier screening programmes are being conducted throughout the world, as this is the only effective way of reducing the incidence of thalassemia major births [11][12][13][14]. In Pakistan ß thalassemia has a carrier rate of 5%.…”

Risk Factors Related to Severe Outcome in RhD Hemolytic Disease of the Fetus and Newborn

“…Thus, immature fetuses are subjected to intrauterine transfusion therapy to treat moderate or severe anemia and avoid the development of such conditions as hydrops and intrauterine death. 11 Illanes & Soothill 12 further argue that antenatal therapies can modify but are not able to fully revert the hemolytic process, determining that surveillance and neonatal care are necessary measures for an adequate outcome during follow-up. When studying the early outcome of infants subjected to intrauterine transfusion therapy, McGlone et al, 13 observed that exchange transfusion was necessary in 20% of newborns.…”

“…More severe fetuses that underwent intrauterine transfusion therapy had scheduled cesarean section deliveries, which increased the rate of complications related to prematurity, such as hyaline membrane syndrome. 11 Currently, the trend in the management of these fetuses is to keep them in a serial intrauterine transfusion therapy treatment plan up to the 35th week, with a delivery planned for three weeks later. This management plan has had good results with respect to neonatal outcome and had even reduced the need for exchange transfusion.…”

Management of alloimmunized patients

“…Two publications, one from Tunis and one from Brazil [15,16], reinforced the importance of Rh Immune Globulin in pregnant D‐negative women, use of Doppler ultrasound studies of the fetal middle cerebral artery and use of intrauterine transfusion.…”