Red blood cell alloimmunization among Saudi pregnent women in the central province of Saudi Arabia

To determine the incidence of alloimmunization among pregnant women in Saudi Arabia Prospective study King Khaled University, Hospital, Riyadh, Saudi Arabia One thousand one hundred and ninty five pregnant women The rates of alloimmunization among pregnant women subjects by analyzing the blood type of both mother and neonate The largest fraction of alloimmunization involved Rh antigens [52.38%], while other groups such as Kell and Duffy play a less common role. Alloantibodies identified fivety pesofalloantibodiesin addition to nonspecific-autoantibodies. The most frequent [52.38%] were against Rhesus 2.38%; Kell 2.38%; Duffy 2.38%; 4.76% were non-specificantibodiesand33.3%were autoantibodies. Alloimmunization are: anti-D 28.57%, anti-C 4.76% anti-E 14.28% and anti-e 4.76%; only one 2.38% developed anti-K; anti-Jk, one 2.38%; one had anti-Le 2.38%; there was one 2.38% with anti-Fy. 1.84% of the total number of study subjects were alloimmunized by antigens of Rh while 0.08% were alloimmunized to antigens either from Kell, Kidd, Lewis or Dufffy. The relative importance of antigens other than Rh D have increased since the introduction of Rh D prophylactic treatment. Alloimmunization to E, c and Kell antigens can reach significantproportionsofstudied populations and can result in deleterious effects on fetus. The actual risk of alloantibody production during pregnancy is unknown but stimuli for antibody production are feto-maternal bleeds that occur throughout pregnancy

Freqüências dos grupos sangüíneos e incompatibilidades ABO e RhD em puérperas e seus recém-nascidos / Frequencies of blood groups, ABO and Rh D incompatibility in post-delivery women and their liveborn

OBJETIVO: Determinar as freqüências fenotípicas e predizer o risco de incompatibilidade e aloimunização materna RhD na população da Zona Oeste de São Paulo, Brasil. MÉTODOS: Estudo descritivo no qual avaliamos 2372 puérperas e seus recém-nascidos vivos, no período de um ano, tipificadas para os sistemas ABO e RhD por meio de teste de aglutinação em tubo. RESULTADOS: O estudo mostrou os seguintes percentuais: grupo sangüíneo O, 50,67 por cento; A, 32,17 por cento; B, 13,45 por cento; AB, 3,71 por cento; RhD(+), 90,34 por cento e RhD(-), 9,66 por cento. A ocorrência de incompatibilidade materno-fetal foi de 18,4 por cento para o sistema ABO e de 7 por cento para o RhD. CONCLUSÃO: O contingente da população Rh negativa com alto risco para aloimunização RhD foi estimado em 82 por cento, denotando a importância da profilaxia da aloimunização RhD.

OBJECTIVE: This study aimed to assess the frequency of different blood phenotypes and to predict the risk of Rh D alloimmunization and maternal-fetal incompatibility in a Brazilian population living in the West zone of the city of São Paulo - Brazil. METHODS: This descriptive study evaluated 2,372 post-delivery women and their liveborn during one year. Blood types were analyzed by means of tube agglutination tests. RESULTS: The blood type frequencies were: 50.67 O, 32.17 A, 13.45 B, 3.75 AB, 90.34 Rh D(+) and 9.66 Rh D(-). ABO maternal-fetal incompatibility was detected in 18.4 percent and Rh D incompatibility in 7 percent. CONCLUSION: The fraction of Rh D(-) population at high risk for Rh D alloimmunization was 82 percent, emphasizing the importance of Rh D alloimmunization profilaxis.

Sangrado transvaginal durante el embarazo, como factor de riesgo para isoinmunización al antígeno Rhesus-D / Transvaginal bleeding during pregnancy associated with Rhesus-D isoimmunization

OBJETIVO: Evaluar el sangrado transvaginal en cualquier etapa del embarazo como factor de riesgo para la sensibilización al antígeno eritrocitario Rhesus-D en mujeres previamente no isoinmunizadas (Rh(-)NI), como una alternativa para la aplicación rutinaria de gama-globulina anti-D a la semana 28 de gestación. MATERIAL Y MÉTODOS: Estudio de casos y controles consecutivos, efectuado en el Instituto Nacional de Perinatología de la Ciudad de México, en el periodo de 1995 a 2001.Casos (n=24), pacientes Rh(-)NI que mostraron seroconversión positiva de anticuerpos contra el componente D del antígeno Rh durante el embarazo o en el puerperio inmediato. Controles (n=24), mujeres Rh(-)NI, captadas consecutivamente y que no presentaron seroconversión positiva de anticuerpos Anti-D. En todos los casos los recién nacidos fueron Rh positivos. Ninguna de las pacientes recibió inmunoprofilaxis Anti-D a la semana 28 de gestación. Se evaluaron periodos de sangrado transvaginal en cualquier etapa del embarazo y antes del inicio del trabajo de parto. Se estimaron razones de probabilidad e intervalos de confianza de 95 por ciento. RESULTADOS: La presencia de sangrado transvaginal se observó en 18/24 (75 por ciento) de los casos y en 5/24 de los controles (20 por ciento). La actividad uterina pretérmino y la amenaza de aborto fueron las causas más frecuentes identificadas como causa de este sangrado. La presencia de uno solo de estos eventos durante cualquier etapa del embarazo aumentó 11.4 veces (IC 95 por ciento 2.9-44.0) el riesgo de sensibilización al antígeno eritrocitario Rh-D, y si el sangrado se presentó después de la semana 20 el riesgo se incrementó 5.0 veces (IC 95 por ciento 1.3-19.1). La presencia de sangrado antes de la semana 20 no se asoció con un incremento significativo en el riesgo de sensibilización (OR=7.6, IC 95 por ciento 0.8-69.5). CONCLUSIONES: En presencia de cualquier sangrado transvaginal durante el embarazo en una paciente Rh-NI...

OBJECTIVE: The aim of the present study was to evaluate transvaginal bleeding (TVB) as a risk factor for Rhesus isoimmunization during pregnancy, in order to optimize the application of Anti-D gammaglobulin in non-immunized pregnant women, as an alternative to the routine application of Anti-D at 28 weeks of gestation. MATERIAL AND METHODS: This case-control study was conducted from 1995 to 2001 at Mexico's National Perinatology Institute. Cases (n=24) were non-immunized pregnant women who showed positive anti-D antibody seroconversion during pregnancy or during the early puerperium. Controls (n=24) were non-immunized pregnant women who enrolled after each case, with similar clinical characteristics but who had no anti-D antibody seroconversion during pregnancy. In all cases the newborns were Rh-positive. None of the patients received immunoprofilaxis at 28 weeks of gestation. The presence of TVB was recorded at any stage of pregnancy and before labor. Odds ratios with 95 percent confidence intervals were used to assess associations. RESULTS: TVB was observed in 18/24 (75 percent) cases and in 5/24 (20 percent) controls. Preterm uterine contractions and threatened miscarriage were the most frequent causes of TVB. The presence of one TVB event during pregnancy increased 11.4 times (95 percent CI 2.9-44.0) the likelihood of Rhesus isoimmunization. TVB after 20 weeks of gestation increased the likelihood 5.0 times (95 percentCI 1.3-19.1). TVB before 20 weeks of gestation was not significantly associated with Rh isoimmunization (OR=7.6, 95 percentCI 0.8-69.5). CONCLUSIONS: Prophylaxis with anti-D gammaglobulin should be given to all non-immunized Rhesus-negative pregnant woman with TVB at any stage of pregnancy.

Role of HLA antigens in Rh (D) alloimmunized pregnant women from Mumbai, Maharashtra, India.

Immunogenetic studies in various diseases provide potential genetic markers. We have studied the incidence of HLA A, B, C, DR and DQ loci antigen in Rh (D) antigen isoimmunized mothers compared to those nonimmunized isoimmunized Rh negative mothers. Seventy six mothers who were immunized to Rh (D) antigen due to pregnancy (responders) and fifty four mothers who did not develop Rh (D) isoimmunization despite positive pregnancies (nonresponders) were selected for the study. Standard methods of serological HLA typing, ABO and Rh (D) groups, and screening for Rh D antibodies were used. 392 unrelated individuals from the population were compared as controls. In addition 45 unrelated individuals from the same population were typed for HLA DRB and DQB gene using PCR-SSP kits. The genotype frequencies of HLA A2, A3, A28, B13, B17, B35, B52, B60, Cw2, Cw6, DR4, and DQ3 were significantly increased, while the frequencies of the HLA A11, A29, A31, B7, B37, B51, Cw1 and DR9 were decreased in the responder women when compared to the non-responder women. HLA A30 (19) split antigen was not identified in immunized women while HLA A23 (9) split antigen was not identified in non immunized women. HLA A3, B17, Cw2 and DR4 showed a significant relative risk among the immunized responder women. When compared with Rh immunized women (responders) reported from USA, England and Hungary the phenotype frequencies of HLA A11, A24, A28, B5, B17, B40, DR2 and DR5 were increased while HLA A23, B8, B18, and DR6 were decreased in the Indian Rh immunized women. Two locus haplotype frequency analysis observed among the responders women revealed that among the significant haplotypes expressed A2-B5, B7-Cw1, DR2-DQ1 were highly significant haplotypes in positive linkage, while A1-B5, and A1-B7 were in significant negative linkage disequilibrium. The haplotype frequencies were <or= one when these common hapoltypes were compared with control population. Thus in the present study it is evident that the inheritance of HLA A3, B17, Cw2 and DR4 increases the relative risk factor by 2.6 times among Indian Rh isoimmunized women. Further, it is evident that there are significant differences in the observed HLA antigen frequencies and two locus haplotypes in Rh isoimmunized women when compared to women from USA, UK and Hungary due to extreme HLA polymorphism in different populations of the world.

Fetal outcome following intrauterine intravascular transfusion in rhesus alloimmunization.

The outcome of 14 pregnancies with severe rhesus alloimmunization was analyzed over a period of 16 months. Group A consisted of 7 cases who received ultrasound guided intravascular intrauterine packed red blood cell transfusions via the umbilical vein after determining fetal blood group and hematocrit. The outcome of these cases was compared with another 7 cases (Group B), who did not require intrauterine transfusions. The 7 cases in Group A received a total of 25 intrauterine transfusions between 25 to 33 weeks gestation. Procedure related complications encountered were transient fetal bradycardia on 4 occasions, difficulty in cord cannulation due to fetal movements in 2 cases and transient bleeding at puncture site in 2 cases. These complications were not associated with any maternal or fetal consequences. There was no procedure related mortality. Mean cord hemoglobin in Group A (12.52 g/dl) was significantly higher (p < 0.05) than in Group B (8.5 g/dl), and mean cord indirect serum bilirubin was significantly lower (p < 0.1) in Group A (2.5 mg/dl) than in Group B (5.8 mg/dl). Three neonates in Group A required one exchange transfusion each, as compared to all 7 in Group B who required a total of 12 exchange transfusions. All neonates in Group B survived, whereas 2 expired in Group A, one of severe intravascular coagulopathy and the other due to prematurity and hyaline membrane disease. Percutaneous ultrasound guided umbilical blood transfusions directly into the vascular system appears to be safe in experienced hands and has the potential to improve the prognosis of the severely alloimmunized fetus.

Isoinmunización al factor Kell, durante el embarazo / Isoimmunization to Kell factor during pregnancy

Se presenta un caso clínico en paciente embarazada de 28 años Rh (-) con isoinmunización al factor Kell (Kell K+) que dió a luz un mortinato hidrópico Kell +; con anticuerpos circulantes anti Kell