Successful management of severe Kell alloimmunization in pregnancy with intravenous immune globulin

Hemolytic Disease of the Fetus and Newborn (HDFN) is a condition that affects 1 to 2 out of 1000 patients during pregnancy (1). When an alloantibody is present, it is essential to identify its nature in order to organize appropriate follow-up. Kell-mediated HDFN is rare; it occurs in about 5% of Kell alloimmunized pregnant women. It is important to note that in case of anti-Kell immunization, the severity of HDFN is not correlated with maternal antibody titers, and anemia tends to occur earlier and more severely. Therefore, early diagnosing and management of this condition is crucial. In the management of severe fetal anemia due to Kell immunization, available treatments include in utero transfusion (IUT), immunoglobulin therapy. Other alternative treatments exist, such as plasmapheresis. Intravenous immunoglobulin (IVIG), a noninvasive therapeutic approach, acts through multiple mechanisms. IVIG has been evaluated in cases of RhD immunization with high maternal antibody titers and a history of pregnancies involving early hydrops or intrauterine death. Regarding the potential benefits of intravenous IgG therapy, it may delay the need for early IUT, reduce the overall reliance on IUT, and have a positive impact on obstetric outcomes. This case of IV IgG therapy of anti-Kell immunization offers a thought-provoking avenue for future exploration.

A novel pyrosequencing strategy for RHD zygosity for predicting risk of hemolytic disease of the fetus and newborn

OBJECTIVE

The aim of this study was the development of an accurate and quantitative pyrosequence (PSQ) method for paternal RHD zygosity detection to help risk management of hemolytic disease of the fetus and newborn (HDFN).

METHODS

Blood samples from 96 individuals were genotyped for RHD zygosity using pyrosequencing assay. To validate the accuracy of pyrosequencing results, all the samples were then detected by the mismatch polymerase chain reaction with sequence-specific primers (PCR-SSP) method and Sanger DNA sequencing. Serological tests were performed to assess RhD phenotypes.

RESULTS

Serological results revealed that 36 cases were RhD-positive and 60 cases were RhD-negative. The concordance rate between pyrosequencing assay and mismatch PCR-SSP assay was 94.8% (91/96). There were 5 discordant results between pyrosequencing and the mismatch PCR-SSP assay. Sanger sequencing confirmed that the pyrosequencing assay correctly assigned zygosity for the 5 samples.

CONCLUSION

This DNA pyrosequencing method accurately detect RHD zygosity and will help risk management of pregnancies that are at risk of HDFN.

A study on diagnostic performance of different immunohematological diagnostic tests in assessing the prevalence of ABO Hemolytic Disease of Newborn in the antenatal O group mothers and their neonatal outcome in a tertiary care hospital in Northern India

BACKGROUND

Hemolytic disease of the newborn (HDN) results in the decreased lifespan of the red cells. HDN related to ABO incompatibility is mostly unnoticed because routine screening is not being done. This study was done to assess the prevalence of ABO-HDN and to compare different immunohematological tests. Methods-In this study 213 O group mothers and the 122 ABO-incompatible newborns born to them were included. Quantifying the maternal IgG anti-A/anti-B antibody titer was done by Conventional Tube Technique (CTT) using Dithiothreitol (DTT) pretreated maternal serum. Hemolysin test was performed on the mothers having titer > 256. These cases were followed up and, after delivery, were monitored for ABO HDN, along with direct antiglobulin testing and elution studies. The prevalence of ABO-HDN was calculated, and the different diagnostic parameters of the tests were calculated. Results- The prevalence of ABO-HDN in our population was estimated to be 1.7%, 6.1% & 10.6% in our population, O group mothers, and O group mothers with ABOincompatible newborns, respectively. Maternal titer≥ 512 strongly correlated with ABOHDN. DAT positivity is a good predictor of ABO-HDN, especially using sensitive techniques. Maternal IgG titers have the highest sensitivity & Negative Predictive Value, while DAT has the highest specificity & Positive Predictive Value. Conclusion - Maternal ABO antibody titration may be advocated in the centers to identify high-risk groups. It can advocate institutional delivery and dedicated follow-up of newborns with ABO-HDN. Blood grouping & DAT may be performed in all newborns born to O blood group to identify high-risk cases.

Application of anti-D immunoglobulin in D-negative pregnant women in China

This article summarizes the current situation of anti-D immunoglobulin (anti-D-Ig) use in RhD-negative pregnant women at home and abroad. The article describes the concept, research and development history, and domestic and foreign applications of anti-D-Ig and points out that anti-D-Ig has not been widely used in China, mainly due to reasons such as unavailability in the domestic market and non-standard current application strategies. The article focuses on analyzing the genetic and immunological characteristics of RhD-negative populations in China. The main manifestations were that the total number of hemolytic disease of the newborn (HDN) relatively high and D variant type. In particular, there are more Asian-type DEL, the importance of clinical application of anti-D-Ig was pointed out, and its antibody-mediated immunosuppressive mechanism was analyzed, which mainly includes red blood cell clearance, epitope blocking/steric hindrance, and Fc γ R Ⅱ B receptor mediated B cell inhibition, anti-D-Ig glycosylation, etc.; clarify the testing strategies of RhD blood group that should be adopted in response to the negative initial screening of pregnant and postpartum women; this article elaborates on the necessity of using anti-D-Ig in RhD-negative mothers after miscarriage or miscarriage, as well as the limitations of its application both domestically and internationally. It also proposes a solution strategy for detecting RhD blood group incompatibility HDFN as early as possible, diagnosing it in a timely manner, and using anti-D-Ig for its prevention and treatment. If the DEL gene is defined as an Asian-type DEL, anti-D-Ig prophylaxis in women would be unnecessary. Finally, based on the specificity of RhD-negative individuals, the article looks forward to the application trend of anti-D-Ig in China. It also called for related drugs to be listed in China as soon as possible and included in medical insurance.

Neonatal hemolytic disease: How should we use indirect and direct antiglobulin tests?

BACKGROUND

In newborns with hemolysis, the direct antiglobulin test (DAT) and indirect antiglobulin test (IAT) play a key role in demonstrating the presence of an immune cause. We aimed to emphasize the importance of IAT in mothers of DAT-positive babies.

METHODS

DAT was performed with forward blood grouping on cord blood in term babies who were born between September 2020 and September 2022. IAT was performed in the mothers of the babies who were found to have a positive DAT and antibody identification was performed in the mothers who were found to have a positive IAT. Specific antibodies detected and identified were associated with the clinical course.

RESULTS

The study included 2769 babies and their mothers. The prevalence of DAT positivity was found to be 3.3% (87 of 2661). In DAT-positive babies, the rate of ABO incompatibility was 45.9%, the rate of RhD incompatibility was 5.7% and the rate of RhD and ABO incompatibility in association was 10.3%. The rate of subgroup incompatibility and other red blood cell antibodies was 18.3%. Phototherapy was applied because of indirect hyperbilirubinemia in 16.6% of the DAT-negative babies and in 51.5% of the DAT-positive babies. The need for phototherapy was significantly higher in DAT-positive infants (p < 0.01). Severe hemolytic disease of the newborn, bilirubin level, duration of phototherapy and use of intravenous immunoglobulin were found to be significantly higher in the babies whose mothers were IAT positive compared with the babies whose mothers were IAT negative (p < 0.01).

CONCLUSIONS

IAT should be performed on all pregnant women. When screening with IAT is not performed during pregnancy, performing DAT in the baby plays a key role. We showed that the clinical course was more severe when mothers of DAT-positive babies were IAT positive.

Comparison of automated solid phase versus manual saline indirect antiglobulin test methodology for non-ABO antibody titration: Implications for perinatal antibody monitoring

BACKGROUND

Accurate antibody titration is crucial in prenatal evaluations to identify patients who need clinical monitoring for hemolytic disease of the fetus and newborn (HDFN) causing fetal anemia. This study compares the established gold standard method of manual tube saline indirect antiglobulin testing (SIAT) with the newer automated solid phase (ASP) method of antibody titration and aims to establish the critical titer threshold for ASP that corresponds to the previously established SIAT critical threshold of ≥16 used in our laboratory.

STUDY DESIGN AND METHODS

One hundred fifty-seven prenatal and donor plasma samples with known antibodies were tested using both SIAT and ASP methodologies and results were compared.

RESULTS

The study found that ASP titers were, on average, 1.33 dilutions higher than SIAT titers. The critical titer cutoff for ASP was determined to be ≥32, which is one tube higher than the SIAT cutoff of ≥16.

DISCUSSION

The ASP method for antibody titration offers greater reproducibility and efficiency compared with manual SIAT titration. This study suggests that a titer cutoff of ≥32 is appropriate for most clinically significant antibodies using ASP. However, further research is needed to determine the comparability of ASP with SIAT in samples with multiple antibodies, anti-M antibodies, and other less common antibodies. Validation of the ASP titer cutoff against HDFN clinical outcomes is required before implementing this test for routine use in perinatal antibody titration.

Immunohematological testing and transfusion management of the prenatal patient

The primary indication for immunohematological testing in the prenatal patient is to detect and identify maternal red cell antibodies. If there are antibodies that are expected to hemolyze the fetus' red cells, their strength of reactivity must be tested, and the fetus' antigen status determined. After delivery, testing is performed to assess the extent of fetomaternal hemorrhage, as a large hemorrhage may require other therapeutic interventions. Another major role for immunohematological testing is to select blood components appropriately when intrauterine transfusion is required for fetal anemia resulting from maternal alloimmunization or some other cause. Supplementation with molecular methods has transformed the practice of immunohematology, particularly as it applies to typing for the D antigen of the Rh blood group system. Notwithstanding the advances in testing, close coordination and communication between the transfusion service and the obstetrics service are the foundation for ensuring the finest care for prenatal patients, and for new mothers and their infants. This review describes testing and transfusion practices for prenatal patients, using case presentations to highlight the management of selected immunohematological findings. It also includes a discussion of key patient management topics that are currently unresolved.

A Rare Case of Hemolytic Disease of the Fetus and Newborn Caused by Anti-s Antibody in a Chinese Patient

BACKGROUND

Anti-s is a rare alloantibody, and the reported cases of hemolytic disease of the fetus and newborn (HDFN) caused by anti-s are limited to non-Asian populations.

METHODS

Here, we report the case of a Chinese woman with a history of multiple pregnancies who developed an alloantibody with anti-s specificity.

RESULTS

Her newborn developed HDFN caused by anti-s but the clinical symptoms were not serious. After supportive treatment and bilirubin light phototherapy, the baby was discharged with a good prognosis.

CONCLUSIONS

This is the first reported case of anti-s-induced HDFN in a Chinese patient, highlighting the need for further research in the Asian population.

Maternal Cold-Reacting Immunoglobulin G Anti-M of MNS Blood Group System Causing Hemolytic Disease of the Fetus

Several cases of the hemolytic disease of the fetus and newborn (HDFN) caused by immunoglobulin G (IgG) anti-M antibodies have been reported, in which almost all the HDFN-associated anti-M were warmly reacting. Here we report two cases of severe HDFN associated with cold-reacting IgG anti-M. In both cases, pregnancy was terminated, in weeks 33 and 23 respectively, due to a diagnosis of fetal growth retardation (FGR). To our knowledge, these are the most severe HDFN cases caused by cold-reacting IgG anti-M.

Clinical value of different anti-D immunoglobulin strategies for preventing Rh hemolytic disease of the fetus and newborn: A network meta-analysis

BACKGROUND

Several anti-D immunoglobulin strategies exist for preventing Rh hemolytic disease of the fetus and newborn. This study systematically assessed the clinical value of those therapeutic strategies.

METHODS

The Web of Science, PubMed, EMBASE, China National Knowledge Infrastructure (CNKI) and Wanfang databases were searched for eligible studies that evaluated the value of different anti-D immunoglobulin strategies in preventing maternal anti-D antibody sensitization. Combined odds ratios (ORs) and their 95% confidence intervals (CIs) were calculated. The network meta-analysis was conducted using Stata 14.2 and WinBUGS 1.4.3 software.

RESULTS

Twenty-four original studies involving 64860 patients were included. Among all therapeutic measures, injecting 300 μg anti-D immunoglobulin at 28 and 34 gestational weeks (antenatal 5/E) appeared to be the most effective measure for preventing maternal antibody sensitization (surface under the cumulative ranking curve [SUCRA] = 96.8%), while a single injection at 28 gestational weeks (SUCRA = 89.2%) was the second most effective. Administering no injection or a placebo (SUCRA = 0.0%) was the least effective intervention measure.

CONCLUSION

Among the therapeutic measures, antenatal 5/E appeared to be the best method for reducing the positive incidence of anti-D antibodies in the maternal serum; thus, it may be the most effective treatment for preventing fetal hemolytic disease.

Resolving Blocked Antigen Phenomenon in Hemolytic Disease of the Fetus and Newborn Due to Anti-K

High-titer antibodies are a cause of false-negative reactions in red blood cell antigen phenotyping, an event referred to as blocked antigen phenomenon (BAP). In hemolytic disease of the fetus and newborn, BAP complicates laboratory workups as fetal phenotype is helpful in confirming the responsible antibody. Acid elution techniques, techniques using ethylenediaminetetraacetic glycine acid, as well as those using chloroquine diphosphate have been used to resolve BAP; however, ethylenediaminetetraacetic glycine acid destroys K-antigen expression and chloroquine diphosphate is not always effective. We report a case of severe hemolytic disease of the fetus and newborn from anti-K where a modified gentle heat elution resolved BAP. Although infrequently considered with isolated reports in the literature, heat elution is simple, is effective, and involves readily available materials in most blood banks.

Predicting anti-Kell-mediated hemolytic disease of the fetus and newborn: diagnostic accuracy of laboratory management

BACKGROUND

There is controversy on critical cut-off values of laboratory testing to select pregnancies at increased risk for anti-Kell-mediated hemolytic disease of the fetus and newborn. Without early detection and treatment, anti-Kell-mediated hemolytic disease of the fetus and newborn may result in progressive fetal anemia, fetal hydrops, asphyxia, and perinatal death.

OBJECTIVE

We aimed to determine the value of repeated anti-Kell titer determination and biological activity measurement using the antibody-dependent cellular cytotoxicity test determination in the management of pregnancies at risk for anti-Kell-mediated hemolytic disease of the fetus and newborn.

STUDY DESIGN

This was a retrospective cohort study of pregnancies with anti-Kell and a Kell-positive fetus, identified from January 1999 through April 2015. Laboratory test results and clinical outcome were collected from the Dutch nationwide screening program and the national reference center for fetal therapy in The Netherlands, the Leiden University Medical Center. Diagnostic accuracy was measured (receiver operating characteristic curves, sensitivity, specificity, positive and negative predictive values) for anti-Kell titers and antibody-dependent cellular cytotoxicity test. The relationship between the titer and antibody-dependent cellular cytotoxicity measurements and the 2 foregoing measurements were computed with a Pearson product-moment correlation coefficient.

RESULTS

In a 16-year unselected cohort, representing screening results of 3.2 million pregnancies resulting in live births in The Netherlands, we identified 1026 Kell-immunized pregnancies. In all, 93 pregnant women had anti-Kell and a Kell-positive child, without other red cell alloantibodies. In all, 49 children (53%) needed intrauterine or postnatal transfusion therapy. The first anti-Kell titer showed already a high diagnostic accuracy with an area under the curve of 91%. The optimal cut-off point for the titer was 4 (sensitivity 100%; 95% confidence interval, 91-100), specificity 27% (95% confidence interval, 15-43), and positive predictive value 60% (49-71%). The antibody-dependent cellular cytotoxicity test was not informative to select high-risk pregnancies. Linear regression showed no significant change during pregnancy, when antibody titer and antibody-dependent cellular cytotoxicity test results were compared with every 2 foregoing measurements (P < .0001).

CONCLUSION

Early determination of the anti-Kell titer is sufficient to select pregnancies at increased risk for hemolytic disease of the fetus and newborn with need for transfusion therapy. If the Kell status of the fetus is known to be positive, a titer of ≥4 can be used to target intensive clinical monitoring.

Jk3 alloantibodies during pregnancy-blood bank management and hemolytic disease of the fetus and newborn risk

BACKGROUND

The Kidd-null phenotype, Jk(a-b-), occurs in individuals who do not express the JK glycoprotein. Jk(a-b-) individuals can make an antibody against the Jk3 antigen, a high-incidence antigen present in more than 99.9% of most populations. This presents many challenges to the blood bank including identification of the antibody, masking of other antibodies, and how to provide transfusion support given the rarity of Jk3-negative blood products. Kidd antibodies may cause acute and delayed hemolytic reactions as well as hemolytic disease of the fetus and newborn (HDFN). In this article, we present a series of four practical cases of pregnant women with the anti-Jk3 alloantibody that demonstrate a range of clinical presentations of Kidd-related HDFN.

STUDY DESIGN AND METHODS

We retrospectively reviewed the clinical and blood bank records for four patients and their newborns encountered at institutions in Tennessee, Missouri, Hawaii, and Guam with an anti-Jk3 identified during pregnancy.

RESULTS

Two cases showed no significant evidence for HDFN, while two cases were of mild-to-moderate severity requiring early delivery due to elevated middle cerebral artery (MCA) flow velocities but requiring only phototherapy for hyperbilirubinemia. No intrauterine or neonatal transfusions were necessary. Anti-Jk3 alloantibody titers ranged from 2 to 128.

CONCLUSION

Clinical manifestations of anti-Jk3 HDFN are generally mild to moderate. Anti-Jk3 titers were not found to correlate directly with HDFN severity. We suggest a titer of 16 to 32 as a cutoff for implementing enhanced monitoring of fetal MCA flow velocities, as such titers may be indicative of elevated HDFN risk.

Anti-M induced severe haemolytic disease of foetus and newborn in a Malay woman with recurrent pregnancy loss

Haemolytic disease of the foetus and newborn (HDFN) is caused by maternal red blood cells (RBC) alloimmunisation resulted from incompatibility of maternal and foetal RBCs. However, only a few HDFN attributed to anti-M were reported, varying from asymptomatic to severe anaemia with hydrops foetalis and even intrauterine death. A case of severe HDFN due to anti-M alloantibody from an alloimmunized grandmultiparous Malay woman with recurrent pregnancy loss is reported here. The newborn was delivered with severe and prolonged anaemia which required frequent RBC transfusions, intensive phototherapy and intravenous immunoglobulin administration. Although anti-M is rarely known to cause severe HDFN, a careful serological work-up and close assessment of foetal well-being is important, similar to the management of RhD HDFN. Alloimmunisation with anti-M type can lead to severe HDFN and even foetal loss.

Blocked D phenomenon and relevance of maternal serologic testing

A blood requisition for double-volume exchange transfusion was received for a 2-day-old male child born to a 29-year-old multiparous female (P2002) referred to our institute having neonatal jaundice with encephalopathy; no maternal sample was received. the neonatal blood sample was typed as group A, D-, and the direct antiglobulin test (DAT) was strongly positive (4+) using the gel method. Mono-specific DAT showed the presence of IgG antibodies on neonatal red blood cells (RBCs). Acid elution and gentle heat elution (at 56°C) confirmed the presence of anti-D on neonatal RBCs. The baby received two exchange transfusions with group O, D-, packed RBCs compatible with his own serum. Later, on day 3, the neonate's mother was typed as group AB, D-, and her serum revealed the presence of alloanti-D, -C, and -S reactive in the anti-human globulin phase. The anti-D titer was 1024. this report highlights the "blocking" phenomenon caused by maternal anti-D in a case of hemolytic disease of fetus and newborn with a positive DAT.

[Rh alloimmunization in pregnant women, a look to diagnosis and therapeutic approach]

Prior to the onset of immunoglobulin antiD, many of the fetuses of mothers negative for the antigen "D" developing severe disease, history of prenatal diagnosis of alloimmunization is the perfect example of constructive effort by a diagnosis in order to identify cases in need of therapy to decrease morbidity and increase survival with the least number of invasive procedures and reducing the risks associated with them. Today it is difficult to determine the true prevalence of the disease in our environment, but the understanding of the pathophysiology has helped the evolution of diagnostic tests and better treatment approach to positively impact the evolution of the disease.

Diagnostic accuracy of routine antenatal determination of fetal RHD status across gestation: population based cohort study

OBJECTIVES

To assess the accuracy of fetal RHD genotyping using cell-free fetal DNA in maternal plasma at different gestational ages.

DESIGN

A prospective multicentre cohort study.

SETTING

Seven maternity units in England.

PARTICIPANTS

RhD negative pregnant women who booked for antenatal care before 24 weeks' gestation.

INTERVENTIONS

Women who gave consent for fetal RHD genotyping had blood taken at the time of booking for antenatal care and, when possible, at other routine visits such as for Down's syndrome screening between 11 and 21 weeks' gestation, at the anomaly scan at 18-21 weeks, and in the third trimester when blood was taken for the routine antibody check. The results of cord blood analysis, done routinely in RhD negative pregnancies, were also obtained to confirm the fetal RHD genotyping.

MAIN OUTCOME MEASURES

The accuracy of fetal RHD genotyping compared with RhD status predicted by cord blood serology.

RESULTS

Up to four analyses per woman were performed in 2288 women, generating 4913 assessable fetal results. Sensitivity for detection of fetal RHD positivity was 96.85% (94.95% to 98.05%), 99.83% (99.06% to 99.97%), 99.67% (98.17% to 99.94%), 99.82% (98.96% to 99.97%), and 100% (99.59% to 100%) at <11, 11-13, 14-17, 18-23, and >23 completed weeks' gestation, respectively. Before 11 weeks' gestation 16/865 (1.85%) babies tested were falsely predicted as RHD negative.

CONCLUSIONS

Mass throughput fetal RHD genotyping is sufficiently accurate for the prediction of RhD type if it is performed from 11 weeks' gestation. Testing before this time could result in a small but significant number of babies being incorrectly classified as RHD negative. These mothers would not receive anti-RhD immunoglobulin, and there would be a risk of haemolytic disease of the newborn in subsequent pregnancies.

[Haemolytic disease of the fetus and newborn/HDFN/timing in pregnant women and prophylaxis]

Haemolytic disease of the fetus and newborn/HDFN/is a condition in which the lifespan of the fetal or newborn infants red cells is shortened by the action of maternal antibodies against antigens present on the infants red cells. The most common routes of maternal sensitization are via blood transfusion or fetomaternal hemorrhage. With the institution of antenatal Rhesus (Rh) D immunoglobulin prophylaxis, the frequency of maternal alloimmunization in Rh D-negative women has decreased significantly. The prevention and treatment of Rh D alloimmunization is a true success story in obstetrics. This article present the reasons for the persistence of the anti-D alloimmunization, protocol for the prevention and diagnosis of HDFN, immunohematological management of all pregnant women, critical titre, protocol and timing in alloimmunized pregnant women.

Significance of prenatal joint detection of ABO antibody titers and irregular antibodies in pregnant women with type O blood

OBJECTIVE

To investigate the effects of blood transfusion and number of pregnancies on ABO antibody titers and irregular antibodies in pregnant women with type O blood.

MATERIALS AND METHODS

The study included 4,200 pregnant women with type O blood (their husbands were with non-O type blood) that were divided into transfusion group and non-transfusion group, according to whether they had a history of blood transfusion. The both groups were respectively divided into three subgroups (the number of pregnancies was one, two, and > or = three). The ABO antibody titers and irregular antibodies were detected at the same time. The effects ofABO antibody titers and irregular antibodies on hemolytic disease of the newborn (HDN) were discussed.

RESULTS

There was no consistency of ABO antibody titers and existence of irregular antibody. The positive rates of irregular antibody of transfusion group and of the subgroup (number of pregnancies > or = three) were far higher than that of non-transfusion group and of the subgroups (number of pregnancies < three), respectively. All pregnant women with positive irregular antibody in non-transfusion group were with HDN.

CONCLUSIONS

For pregnant women with number of pregnancies > or = three or with history of blood transfusion, the prenatal joint detection of ABO antibody titers and irregular antibodies is helpful for accurately reflecting the in vivo antibody type and level.

Hemolytic disease of the fetus and newborn owing to anti-U, successfully treated with repeated intrauterine transfusions

Hemolytic disease of the fetus and newborn (HDFN) owing to anti-U has rarely been reported. U is part of the MNS system.M and N glycoproteins are located on glycophorin A (GPA); Sand s antigens are on glycophorin B (GPB). Individuals who lack GPB are S- and s- and also lack U. The U- phenotype occurs almost exclusively in the African population and has a very low frequency (0.25%). Anti-U is of immunoglobulin G class and can cause hemolytic transfusion reaction and HDFN. In this report we present the use of a noninvasive method to detect anemia in the fetus and the subsequent use of intrauterine transfusion(IUT) with blood of a very rare phenotype. For the first time, we used deglycerolized and 3-week-old red blood cell units for IUT without signs of adverse reactions and with the expected effect on the hemoglobin value. We conclude that this transfusion strategy could be applied safely.

[Clinical case of the month. Mild hemolytic disease of the newborn due to an anti-Wr(a) antibody]

A Caucasian woman, with a A+ CCD.ee K neg erythrocyte phenotype and no history of blood transfusion, delivered a first child who developed mild anemia. The direct antiglobulin test performed on the newborn red blood cells belonging to the A+ CCD.ee K neg group, was strongly positive for IgG. During the pregnancy and after the delivery, the woman had a negative irregular antibody screening test, using standard red blood cells. However, at birth, using a collection of thawed red blood cells with rare phenotypes (private antigens), the lab showed an antibody anti-Wr(a) in the maternal serum. The activity of the maternal antibody, with a titer of 16, was completely inhibited by dithiothreitol, indicating the nature IgM of the circulating antibody. The presence of the antigen Wr(a) on the surface of the newborn and its biological father red blood cells was confirmed. The concentration of IgG anti-Wr(a) on baby erythrocytes was demonstrated by the presence of the antibody anti-Wr(a) in the eluate. This case illustrates the difficulties to detect antibodies against private antigens on baby erythrocytes, responsible of hemolytic diseases of newborn. Indeed, standard red blood cell panels used for irregular antibodies screening test do not express generally those private antigens.

Clinical significance of maternal anti-Cw antibodies: a review of three cases and literature

Anti Cw antibody is a low frequency immunoglobulin (IgG) against red cell antigen- Cw. It is clinically significant and may cause haemolytic disease of the newborn. Due to its low frequency, it is not included in routine antenatal antibody screening panel. The incidence of Anti Cw antibodies has not been reported in our population. Here, we describe the clinical and laboratory spectra of three pregnant women having low titres anti Cw antibodies. Fortunately, haemolytic disease of the newborn was not encountered in any case.

[High-throughput genotyping multiplex ligation-dependent probe amplification for assisting diagnosis in a case of anti-Di(a)-induced severe hemolytic disease of the newborn]

OBJECTIVE

To report a rare case of hemolytic disease of the newborn (HDN) with kernicterus caused by anti-Di(a) diagnosed using high-throughput genotyping multiplex ligation-dependent probe amplification (MLPA).

METHODS

Conventional serological methods were used to detect the antibodies related with HDN. The genotypes of more than 40 red blood cell antigens for the newborn and her parents were obtained using the high-throughput MLPA assay. The antibody titers were tested using a standard serological method.

RESULTS

The unknown antibody against the low-frequency antigens was predicted based on the primary serological tests. The genotyping results for more than 40 red blood cell antigens of the newborn and her parents showed incompatible antigens of MNS and Diego blood group system, indicating the existence of anti-N or anti-Di(a). Further serological tests confirmed anti-Di(a) existence in the plasma of the newborn and her mother. The titer of anti-Di(a) in the mother's plasma was 1:32.

CONCLUSION

Severe HDN including kernicterus can result from anti-Di(a). High-throughput genotyping MLPA assay can help type some rare antigens in complicated cases. The reagent red cell panels including Di(a)-positive cells are necessary in routine antibody screening test in Chinese population.

Alloimmune neonatal neutropenia and neonatal isoerythrolysis in a Thoroughbred colt

A 3-day-old Thoroughbred colt was originally presented for treatment of neonatal isoerythrolysis, which was treated with a blood transfusion. However, persistent neutropenia was observed despite the absence of detectable infection. Subsequently, a granulocyte agglutination test was performed by incubating the colt's neutrophils with the mare's serum; results were positive, leading to a clinical diagnosis of alloimmune neonatal neutropenia. The diagnosis was further supported via flow cytometric analysis. The colt was hospitalized and treated prophylactically with antimicrobials and 4 separate doses of recombinant human granulocyte colony-stimulating factor (rhG-CSF; 1.4-3.5 µg/kg, subcutaneously) in attempts to maintain the neutrophil count within reference intervals over a 4-week period. The colt's neutrophil count increased after administration of rhG-CSF and eventually stabilized within reference intervals by day 20. The colt maintained normal neutrophil counts after discharge and was reportedly healthy at 6 months of age. Alloimmune neonatal neutropenia should be considered in foals with persistent neutropenia in the absence of infection. Alloimmune neonatal neutropenia can be treated with prophylactic antimicrobials combined with rhG-CSF with a favorable outcome.

N-terminal pro-B-type natriuretic peptide: a potential marker of fetal heart failure in hemolytic disease

OBJECTIVES

The hemolysis of red blood cells due to isoimmunisation results in fetal anaemia and hypoxia leading to fetal heart failure. An assessment of N-terminal pro-B-type natriuretic peptide (NT-proBNP) is a routine practice in adult heart failure. No studies on this marker have been reported in fetal heart failure. The aim of the current study was to investigate changes in fetal NT-proBNP serum concentrations before and after intrauterine transfusions and to assess its value as a marker of fetal heart failure.

DESIGN

Therapy of Rh immunisations was performed in 14 fetuses with 61 intrauterine transfusions. Hemoglobin concentration, red blood cells count, hematocrit and NT-proBNP concentrations were assessed in samples taken before and after each transfusion.

RESULTS

An increase in the concentrations of blood parameters was strongly correlated with a decrease in the concentration of NT-proBNP. NT-proBNP concentrations were the greatest with the smallest Hb (4.0-5.9 g/dl), hematocrit and red blood cell (RBC) concentrations, respectively. An increase in Hb concentration by 1mg/dl and the RBC count by 1M/µl resulted in a corresponding decrease in NT-proBNP concentration by 659.0 and 2 007.1 pg/ml, respectively. The NT-proBNP concentrations decreased significantly following 52 transfusions.

CONCLUSIONS

The fetal serum concentration of NT-proBNP appears to be a satisfactory marker for heart failure in fetuses inflicted with severe anaemia caused by hemolytic disease. Intrauterine therapy decreases the severity of anaemia and reduces the fetal heart failure index. There appears to be a strong inverse correlation between the pre-transfusion NT-proBNP concentration and morphological parameters.

[Noninvasive prenatal diagnosis from maternal plasma in serological conflicts in Poland: current practice and future prospects]

The principles and results of noninvasive prenatal diagnosis in serological conflicts in Poland were described in the following work. Noninvasive fetal genotyping from plasma of immunized mother identifies women carrying fetus without incompatible antigen and risk of hemolytic disease. The presence of fetal RHD gene or RHCE*c/E alleles in maternal plasma is examined routinely in Institute of Hematology and Blood Transfusion in Warsaw. Preliminary results of successful fetal KEL*1 genotyping from maternal blood were obtained.

Should we continue screening rhesus D positive women for the development of atypical antibodies in late pregnancy?

OBJECTIVE

The purpose of this study was to calculate the incidence of the new development of atypical antibodies (other than anti-rhesus D) in women attending for antenatal care, and to assess the clinical impact and cost-effectiveness of a second test to detect these antibodies.

METHOD

A three-year retrospective analysis was undertaken to calculate the number of rhesus positive women who developed new antibodies in the last trimester of pregnancy.

RESULTS

Of 13,143 rhesus positive women, 20 (0.15%) developed new antibodies; fetal outcome was not compromised in any of these cases.

CONCLUSION

Repeat testing in late pregnancy would appear an unnecessary expense in our population.

JAL (RH48) blood group antigen: serologic observations

BACKGROUND

JAL (RH48) is a low-prevalence antigen in the Rh blood group system and anti-JAL has caused hemolytic disease of the newborn. JAL is associated with either a haplotype carrying depressed C and e antigens or one carrying depressed c and e antigens. Blood samples from JAL+ people were tested, published serologic findings were confirmed, serologic studies were extended to include expression of other Rh antigens, and the antibody specificities produced by three sensitized JAL+ probands are reported.

STUDY DESIGN AND METHODS

Red blood cell (RBC) samples from 17 (12 probands) JAL+ persons were tested by hemagglutination using standard methods.

RESULTS

RBCs from both the Caucasian JAL+ probands had the (C)(e) haplotype and weakened C, e, hr(B), and hr(S) antigens. JAL+ samples from black persons had the (c)(e) haplotype and expressed weakened c, e, f, V, VS, hr(B), and hr(S) antigens. Plasma from three sensitized c+e+ JAL+ probands contained alloanti-c, alloanti-e, or alloantibody of apparent anti-Rh17 specificity. This study shows that this alloanti-Rh17-like antibody recognizes the high-prevalence antigen antithetical to JAL that has been named CEST.

CONCLUSIONS

The presence of the JAL antigen has a quantitative (weakening) effect on the expression of C, e, hr(B), and hr(S) antigens in Caucasian persons and of c, e, f, V, VS, hr(B), and hr(S) antigens in people of black African ancestry. A qualitative effect also was demonstrated by the presence of alloanti-c or alloanti-e in the plasma of two transfused c+e+ patients and by an antibody (anti-CEST) that recognizes the high-prevalence antigen antithetical to JAL.

Management of anti-Jka alloimmunization

OBJECTIVE

To determine whether prenatal management using guidelines established for anti-D is applicable to anti-Jka.

STUDY DESIGN

A computerized database containing the records of all alloimmunized pregnancies at The Ohio State University Medical Center with due dates from 1959 to 2008 was used to identify pregnancies affected only by anti-Jka. Only cases with evidence that the newborn was Jka antigen positive were included.

RESULTS

Twenty affected pregnancies met inclusion criteria. Of those, 16 pregnancies required monitoring with serum titers only and 4 were followed with more diagnostic tests as recommended during that time period. One pregnancy with the highest titer of 32 and elevated middle cerebral artery peak systolic velocity (MCA PSV) required 4 intrauterine transfusions for fetal anemia. Another pregnancy with a titer of 32 had an infant who required phototherapy for hemolytic disease of the fetus/newborn (HDFN), with a hemoglobin value of 15.9 g/dL. None of the other 18 infants required any therapy for HDFN.

CONCLUSION

Our case series identified severe disease in 1 of 20 pregnancies from anti-Jka using maternal antibody titer and MCA PSV. Criteria used for monitoring RhD alloimmunization were effective in detecting severe HDFN resulting from to anti-Jka.

[Clinical significance of anti-D IgG screening and titer detection in 286 RhD negative pregnant women]

OBJECTIVE

Anti-D IgG in RhD negative pregnant women is the main antibody of Rh-induced hemolytic disease of newborn (HDN). The study aimed to investigate the clinical significance of anti-D IgG screening and titer detection in RhD negative pregnant women.

METHODS

Sera of 286 RhD negative pregnant women were collected. Microtube column indirect antiglobulin test was used to screen and identify anti-D IgG. The indirect antiglobulin test was used to test the titer of anti-D IgG.

RESULTS

Anti-D IgG was identified in 21 cases (7.3%). The titer of anti-D showed an increasing trend with pregnancy progresses. The clinical outcomes of 12 fetuses (newborns) from positive anti-D pregnant women were observed. Two cases died in utero, 2 cases did not show abnormality and 8 cases had hemolysis. The 8 cases with hemolysis were treated with exchange transfusion or blood transfusion, and they had a good prognosis.

CONCLUSIONS

The screening and titer detection of anti-D IgG in RhD negative pregnant women are valuable in the prediction and treatment of HDN.

Transfusion in the age of molecular diagnostics

DNA-based tests are increasingly being used to predict a blood group phenotype to improve transfusion medicine. This is possible because genes encoding 29 of the 30 blood group systems have been cloned and sequenced, and the molecular bases associated with most antigens have been determined. RBCs carrying a particular antigen, if introduced into the circulation of an individual who lacks that antigen (through transfusion or pregnancy), can elicit an immune response. It is the antibody from such an immune response that causes problems in clinical practice and the reason why antigen-negative blood is required for safe transfusion. The classical method of testing for blood group antigens and antibodies is hemagglutination; however, it has certain limitations, some of which can be overcome by testing DNA. Such testing allows conservation of antibodies for confirmation by hemagglutination of predicted antigen-negativity. High-throughput platforms provide a means to test relatively large numbers of donors, thereby opening the door to change the way antigen-negative blood is provided to patients and to prevent immunization. This review summarizes how molecular approaches, in conjunction with conventional hemagglutination, can be applied in transfusion medicine.

The value of transcutaneous method of bilirubin measurement in newborn population with the risk of ABO hemolytic disease

OBJECTIVE OF THE STUDY. To evaluate the correlation between total serum bilirubin (TSB) and transcutaneous bilirubin (TcB) levels in newborn infants at risk of ABO hemolytic disease. MATERIAL AND METHODS. During a prospective study, 130 full-term (>or=37 weeks of gestation) newborn infants with diagnosed ABO blood group incompatibility were examined. TSB level was measured at the age of 6 hours; further measurements were performed at 24, 48, and 72 hours following the first measurement. Blood samples were collected from the peripheral veins. In clinical laboratory, total serum bilirubin level was measured using Jendrassik-Grof method. TcB level in the forehead was measured using a noninvasive bilirubinometer BiliCheck (SpectRX Inc, Norcross, GA) according to the manufacturer's instructions within +/-30 min after getting a blood sample. RESULTS. During the study, 387 double tests were performed to measure TSB and TcB levels. TSB level (114.83 [62.85] micromol/L) closely correlated with TcB level (111.51 [61.31] micromol/L) (r=0.92, P<0.001). The strongest correlation was reported at the age of 54 hours (r=0.873, P<0.001), the weakest - at the age of 6 hours (r=0.729, P<0.001). TSB and TcB levels showed a strong correlation; the difference between these values was significant (95% CI, 0.70; 5.93; P<0.05). The greatest difference between TSB and TcB levels was detected at the age of 6 hours (5.58 [17.46] micromol/L, 95% CI, 2.55; 8.61; P<0.001). No significant difference was reported at the age of 30, 54, and 78 hours. Using linear regression analysis, it was established that correlation of TSB and TcB was described by equation y=14.13+0.903x. Transcutaneously measured bilirubin level underestimated serum bilirubin level. When at the age of 6 hours TcB level is >or=98 micromol/L, ABO hemolytic disease in newborns may be diagnosed with 100% sensitivity and 98% specificity; positive predictive value was 62% and negative predictive value was 100%. While a newborn's age increases, TcB sensitivity and specificity for diagnosing ABO hemolytic disease decrease. CONCLUSION. While evaluating bilirubin level transcutaneously according to nomograms of serum bilirubin level, the results should be considered with caution, especially for newborns with a risk of ABO hemolytic disease. The hour-specific nomograms of transcutaneous bilirubin level should be used to evaluate hyperbilirubinemia using only a noninvasive method.