Serum malondialdehyde concentration in babies with hyperbilirubinaemia.
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AIM: To determine lipid peroxide concentrations in the first 10 days of life. METHODS: Malondialdehyde concentrations were investigated in neonates with or without hyperbilirubinaemia during the first 10 days of life. RESULTS: Serum malondialdehyde concentrations were higher in infants with hyperbilirubinaemia than in controls. A positive correlation was found between malondialdehyde and bilirubin concentrations in the study group. When the study group was categorised according to the presence of haemolysis, a significant correlation was found between malondialdehyde and bilirubin concentrations in those infants with hyperbilirubinaemia due to haemolysis. There was no such correlation in those without haemolysis. CONCLUSION: Exchange transfusion rapidly produces variable changes in pro-oxidant and antioxidant plasma concentrations in neonates, which may be responsible for free radical metabolism. The fall in malondialdehyde concentration is probably directly related to its exogenous removal by exchange transfusion. (+info)
Perinatal management of fetal hemolytic disease due to Rh incompatibility combined with fetal alloimmune thrombocytopenia due to HPA-5b incompatibility.
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We report out experience in the perinatal management of a complex case of fetal hemolytic disease primarily due to Rhesus incompatibility combined with fetal alloimmune thrombocytopenia. The lowest fetal hemoglobin and platelet levels were 2.6 g/dl and 13,000/microliter, respectively. Intrauterine treatment consisted of six transfusions of packed red cells into the umbilical vein and one transfusion of platelets. The neonate required four transfusions of packed red cells to correct her hyporegenerative erythropoiesis. Postnatal management also included one platelet transfusion, intravenous immunoglobulins and erythropoietin. Although some degree of fetal thrombocytopenia may invariably be found in fetal red cell incompatibility, other rare causes need to be excluded. (+info)
A likelihood-based method of identifying contaminated lots of blood product.
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BACKGROUND: In 1994 a small cluster of hepatitis-C cases in Rhesus-negative women in Ireland prompted a nationwide screening programme for hepatitis-C antibodies in all anti-D recipients. A total of 55 386 women presented for screening and a history of exposure to anti-D was sought from all those testing positive and a sample of those testing negative. The resulting data comprised 620 antibody-positive and 1708 antibody-negative women with known exposure history, and interest was focused on using these data to estimate the infectivity of anti-D in the period 1970-1993. METHODS: Any exposure to anti-D provides an opportunity for infection, but the infection status at each exposure time is not observed. Instead, the available data from antibody testing only indicate whether at least one of the exposures resulted in infection. Using a simple Bernoulli model to describe the risk of infection in each year, the absence of information regarding which exposure(s) led to infection fits neatly into the framework of 'incomplete data'. Hence the expectation-maximization (EM) algorithm provides estimates of the infectiousness of anti-D in each of the 24 years studied. RESULTS: The analysis highlighted the 1977 anti-D as a source of infection, a fact which was confirmed by laboratory investigation. Other suspect batches were also identified, helping to direct the efforts of laboratory investigators. CONCLUSIONS: We have presented a method to estimate the risk of infection at each exposure time from multiple exposure data. The method can also be used to estimate transmission rates and the risk associated with different sources of infection in a range of infectious disease applications. (+info)
Noninvasive diagnosis by Doppler ultrasonography of fetal anemia due to maternal red-cell alloimmunization. Collaborative Group for Doppler Assessment of the Blood Velocity in Anemic Fetuses.
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BACKGROUND: Invasive techniques such as amniocentesis and cordocentesis are used for diagnosis and treatment in fetuses at risk for anemia due to maternal red-cell alloimmunization. The purpose of our study was to determine the value of noninvasive measurements of the velocity of blood flow in the fetal middle cerebral artery for the diagnosis of fetal anemia. METHODS: We measured the hemoglobin concentration in blood obtained by cordocentesis and also the peak velocity of systolic blood flow in the middle cerebral artery in 111 fetuses at risk for anemia due to maternal red-cell alloimmunization. Peak systolic velocity was measured by Doppler velocimetry. To identify the fetuses with anemia, the hemoglobin values of those at risk were compared with the values in 265 normal fetuses. RESULTS: Fetal hemoglobin concentrations increased with increasing gestational age in the 265 normal fetuses. Among the 111 fetuses at risk for anemia, 41 fetuses did not have anemia; 35 had mild anemia; 4 had moderate anemia; and 31, including 12 with hydrops, had severe anemia. The sensitivity of an increased peak velocity of systolic blood flow in the middle cerebral artery for the prediction of moderate or severe anemia was 100 percent either in the presence or in the absence of hydrops (95 percent confidence interval, 86 to 100 percent for the 23 fetuses without hydrops), with a false positive rate of 12 percent. CONCLUSIONS: In fetuses without hydrops that are at risk because of maternal red-cell alloimmunization, moderate and severe anemia can be detected noninvasively by Doppler ultrasonography on the basis of an increase in the peak velocity of systolic blood flow in the middle cerebral artery. (+info)
Hemolytic disease of the newborn due to anti S antibodies.
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We report a case of hemolytic disease in a newborn due to anti S antibodies. Baby R was born at term to an O+ mother whose antibody screen was positive for phenotype big S. Cord blood eluate revealed anti-S RBC; antigen: RBC typing for S- was positive. Physical examination of baby was unremarkable. The infant's HCT was 44.2 at 6 hours of age. At 48 hours, the HCT decreased to 33.5, bilirubin peaked to 5.4, retic had peaked to 6.8. By seven days, all these values reverted to the normal, and baby has remained asymptomatic. (+info)
Middle cerebral artery peak systolic velocity in the prediction of fetal anemia.
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OBJECTIVE: The fetal middle cerebral artery peak systolic velocity (MCA PSV) has been suggested as a potential test to predict the fetal hematocrit level. We tested the hypothesis that a low fetal hematocrit is associated with an increase in MCA PSV in a prospective study of normal and alloimmunized pregnancies. METHODS: Fetal hematocrit and MCA PSV were obtained in 26 alloimmunized fetuses, immediately before their first fetal blood transfusions between 15 and 35 weeks. Results were compared with the MCA PSVs from 170 control fetuses not at risk of alloimmune anemia between 13 and 37 weeks. RESULTS: In control fetuses, PSV varied with gestation (PSV = 0.56 - 0.032 GA + 0.00086 GA2, where GA is gestational age; R2 = 0.41). The correlation between PSV and hematocrit Z scores (Pearson correlation coefficient r = -0.69) was highly significant (P = 0.0001). Using a PSV > 1 SD, the sensitivity of the test in predicting a fetal hematocrit < 2 SD below the mean was only 64% but the specificity was 100%. However, the sensitivity of the test in predicting a fetal hematocrit < 3 SD and < 4 SD rose to 73% and 83%, while the specificity was still good (93% and 80% respectively). CONCLUSIONS: MCA PSV and fetal hematocrit are highly significantly correlated. The sensitivity of the test was good and the high positive predictive value indicates that the presence of a raised PSV (defined as > 1 SD) is a strong indicator of fetal anemia. In conclusion, MCA PSV is a useful test in clinical practice for the detection of fetal anemia. (+info)
Early neonatal hypocalcaemia.
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In our hospital early neonatal hypocalcaemia is now the major cause of low serum calcium in the neonatal period. Over a 2-year period, only 2 cases of hypocalcaemic convulsions were seen in a total of 8700 deliveries, though 51 infants had early neonatal hypocalcaemia. All sick low birth-weight infants should have daily serum calcium estimations carried out. Calcium supplements should be considered if symptoms of hypocalcaemia are present. (+info)
Identification of alloreactive T-cell epitopes on the Rhesus D protein.
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Although considerable effort has been devoted to characterizing alloantibodies specific for the Rhesus D (RhD) blood group antigen, virtually nothing is known about the helper response that drives their production. Therefore, the aim of this study was to map alloreactive T-cell epitopes on the RhD protein. Peripheral blood mononuclear cells (PBMCs) were obtained from 22 RhD-negative volunteers in whom anti-D alloantibodies had developed after deliberate immunization or RhD-incompatible pregnancy. The PBMCs were stimulated with a panel of up to 68 overlapping synthetic 15-mer peptides spanning the complete sequence of the RhD protein. One or more peptides elicited proliferative responses by PBMCs from all 22 of the alloimmune volunteers but from only 2 of 8 alloantibody-negative control donors. Proliferation of PBMCs from the alloimmune donors was mediated by major histocompatibility complex class II-restricted T cells expressing the CD45RO marker of previous activation or memory. The number of peptides that induced proliferative responses was unrelated to either the frequency of, or time since, exposure to RhD-positive red blood cells, but it correlated strongly (R(s) = 0.75; P <.003) with the level of anti-D antibodies in deliberately immunized donors. The patterns of stimulatory peptides varied among alloimmune volunteers, but particular sequences were commonly recognized, with 4 peptides each eliciting a response in more than 50% of these donors. Identification of such peptides containing dominant alloreactive helper epitopes is the first step in the development of improved or new approaches to preventing hemolytic disease of the newborn that are based on modulating the T-cell response to the RhD protein. (+info)