Hemolytic Disease of the Fetus and Newborn: Historical and Current State

Metabolomics-based study on the significance of differential metabolite binding IgG isoforms in Hemolytic disease of newborn

BACKGROUND

Hemolytic disease of the newborn (HDN) is a common condition that can have a severe impact on the health of newborns due to the hemolytic reactions it triggers. Although numerous studies have focused on understanding the pathogenesis of HDN, there are still many unanswered questions.

METHODS

In this retrospective study, serum samples were collected from 15 healthy newborns and 8 infants diagnosed with hemolytic disease. The relationship between different metabolites and various IgG subtypes in Healthy, HDN and BLI groups was studied by biochemical technique and enzyme-linked immunosorbent assay (ELISA). Metabolomics analysis was conducted to identify the differential metabolites associated with HDN. Subsequently, Pearson's correlation analysis was used to determine the relation of these differential metabolites with IgG isoforms. The relationship between the metabolites and IgG subtypes was observed after treatment.

RESULTS

The study results revealed that infants with hemolytic disease exhibited abnormal elevations in TBA, IgG1, IgG2a, IgG2b, IgG3, and IgG4 levels when compared to healthy newborns. Additionally, differences in metabolite contents were also observed. N, N-DIMETHYLARGININE showed negative correlations with TBA, IgG1, IgG2a, IgG2b, IgG3, and IgG4, while 2-HYDROXYBUTYRATE, AMINOISOBUTANOATE, Inosine, and ALLYL ISOTHIOCYANATE exhibited positive correlations with TBA, IgG1, IgG2a, IgG2b, IgG3, and IgG4. Through metabolomics-based research, we have discovered associations between differential metabolites and different IgG isoforms during the onset of HDN.

CONCLUSION

These findings suggest that changes in metabolite and IgG isoform levels are linked to HDN. Understanding the involvement of IgG isoforms and metabolites can provide valuable guidance for the diagnosis and treatment of HDN.

Blood group genotype matching for transfusion

The last decade has seen significant growth in the application of DNA-based methods for extended antigen typing, and the use of gene sequencing to consider variation in blood group genes to guide clinical care. The challenge for the field now lies in educating professionals, expanding accessibility and standardizing the use of genotyping for routine patient care. Here we discuss applications of genotyping when transfusion is not straightforward including when compatibility cannot be demonstrated by routine methods, when Rh type is unclear, when allo- and auto-antibodies are encountered in stem cell and organ transplantation, for prenatal testing to determine maternal and foetal risk for complications, and Group A subtyping for kidney and platelet donors. We summarize current commercial testing resources and new approaches to testing including high-density arrays and targeted next-generation sequencing (NGS).

Is Feto-Maternal Transfusion after Cesarean Delivery Different in Singleton and Twin Pregnancy?

Background: The aim of the study was to investigate if feto-maternal transfusion was related to the size of the fetal-maternal interface, and, therefore, was larger in twin pregnancy in comparison with singleton pregnancy. Methods: Blood samples from women with singleton (n = 11), and monochorionic (n = 11) and dichorionic (n = 13) twin gestations were tested. Flow cytometry tests with hemoglobin F, glycophorin A, and hemoglobin F and carbonic anhydrase simultaneous staining were used to detect fetal red blood cells and maternal F cells. Results: In all cases, the volume of feto-maternal transfusion was estimated to be low. The highest rate of fetal red blood cells in the maternal circulation was observed in the blood of women with dichorionic twin gestations both before and after delivery. An increase in fetal red blood cells was observed after cesarean section in singletons and twins. The median rate of maternal F cells was 2.23% in singleton, 2.1% in monochorionic and 3.95% in dichorionic pregnancy. Conclusions: Feto-maternal transfusion during pregnancy may be related to the multiplicity and chorionicity of pregnancy.

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.

Intrauterine Transfusion for Rhesus Alloimmunization: A Historical Retrospective Cohort from A Single Reference Center in Brazil

Objective: This study aimed to describe the historical experience of a single reference center in Brazil with intrauterine transfusion (IUT) for Rhesus (Rh) alloimmunization, evaluating the major complications and the perinatal outcomes of this procedure. Methods: This retrospective cohort study evaluated data from medical records of pregnant women between 20 and 34 weeks of gestation whose fetuses underwent IUT by cordocentesis between January 1991 and June 2021. The same experienced examiner performed all procedures. Univariate and multivariate logistic regression was used to assess the effect of fetal hydrops, duration of IUT, post-transfusion cord bleeding time, and bradycardia on death (fetal or neonatal). Results: We analyzed data from 388 IUTs in 169 fetuses of alloimmunized pregnant women with a mean age of 29.3 ± 5.1 years. Death and fetal hydrops were significantly associated at first IUT (p < 0.001). We had two cases of emergency cesarean section (mean of 0.51% per IUT) and three cases of premature rupture of the ovular membranes (mean of 0.77% per procedure). Thirty-six deaths were recorded, including 14 intrauterine and 22 neonatal. A higher percentage of neonatal deaths was observed in the group with post-transfusion cord bleeding time > 120 s (45.8%). The odds of neonatal death were 17.6 and 12.9 times higher in cases with hydrops and bradycardia than in cases without hydrops and bradycardia, respectively. The odds of death (fetal and neonatal) were 79.9 and 92.3 times higher in cases with hydrops and bradycardia than in cases without hydrops and bradycardia, respectively. Conclusions: The most common complications of IUT for Rh alloimmunization were post-transfusion cord bleeding, fetal bradycardia, premature rupture of ovular membranes, and emergency cesarean section. The IUT complication most associated with death (fetal and neonatal) was bradycardia, and the perinatal outcomes were worse in fetuses with hydrops.

Clinical value of combined predictors of RET%, γ-GT, LDH in the ABO neonatal hemolytic disease

Objective

The purpose of this study is to examine the prognostic significance of the amalgamated indicators, reticulocyte percentage (RET%), lactate dehydrogenase (LDH), and γ-Glutamyltransferase (γ-GT), in neonatal ABO hemolytic disease.

Methods

A total of 137 hospitalized children with pathological jaundice were included. Based on their medical conditions, they were categorized into two groups, hemolytic (67 cases) and non-hemolytic (70 cases). Pearson linear correlation and binary logistic multivariate analysis were used to analyze LDH, γ-GT, RET% and hemolysis. Furthermore, the predictive value of the combined predictors of RET%, LDH, and γ-GT on ABO neonatal hemolytic disease was evaluated using the ROC curve analysis.

Results

The laboratory indexes of the two groups were subject to analysis using binary logistic regression to identify suspicious influencing factors. The study revealed that RET%, LDH, and γ-GT were independent risk factors for hemolysis. Pearson linear correlation analysis indicated a positive correlation between LDH and γ-GT with RET% (r = 0.529, P < 0.01; r = 0.526, P = <0.01, respectively). Furthermore, the predictive value of each combined predictor was obtained using the ROC curve, and it was observed that combined predictor L (RET% + LDH + γ-GT)>L1 (RET% + LDH)>L2 (RET% + γ-GT).

Conclusion

Combined predictor L (RET% + LDH + γ-GT)demonstrate its optimal diagnostic efficacy, offering a novel approach towards diagnosing early-onset ABO hemolytic disease of the newborn.

Alloimmune hemolytic disease of the fetus and newborn: genetics, structure, and function of the commonly involved erythrocyte antigens

Hemolytic disease of the fetus and newborn (HDFN) can occur when a pregnant woman has antibody directed against an erythrocyte surface antigen expressed by her fetus. This alloimmune disorder is restricted to situations where transplacental transfer of maternal antibody to the fetus occurs, and binds to fetal erythrocytes, and significantly shortens the red cell lifespan. The pathogenesis of HDFN involves maternal sensitization to erythrocyte "non-self" antigens (those she does not express). Exposure of a woman to a non-self-erythrocyte antigen principally occurs through either a blood transfusion or a pregnancy where paternally derived erythrocyte antigens, expressed by her fetus, enter her circulation, and are immunologically recognized as foreign. This review focuses on the genetics, structure, and function of the erythrocyte antigens that are most frequently involved in the pathogenesis of alloimmune HDFN. By providing this information we aim to convey useful insights to clinicians caring for patients with this condition.

Noninvasive screening of fetal RHD genotype in Chinese pregnant women with serologic RhD-negative phenotype

BACKGROUND

Noninvasive fetal RHD genotyping has been provided to nonimmunized RhD-negative pregnant women to guide anti-D prophylaxis. Among the Chinese, more than 30% of the RhD-negative phenotype is associated with variant RHD alleles, which would limit the accuracy of fetal RHD status prediction; thus, more targeting and proper programs need to be developed.

STUDY DESIGN AND METHODS

Fluorescence quantitative polymerase chain reaction PCR (qPCR) or Sanger sequencing on all RHD exons was used to detect maternal RHD genotypes. For pregnant women with RHD*01N.01 or RHD*01N.03 alleles, the presence of RHD exons 5 and 10 in cell-free DNA was determined by qPCR. For pregnant women with the RHD(1227G>A) allele, high-throughput sequencing on exon 9 of the RHD gene and RHCE gene was used to predict fetal RhD phenotype.

RESULTS

Among 65 cases of Chinese pregnant women with the serologic RhD-negative phenotype, three major genotypes were identified: RHD*01N.01/RHD*01N.01 (61.5%), RHD*01N.01/RHD(1227G>A) or RHD*01N.03/RHD(1227G>A) (20%), and RHD*01N.01/RHD*01N.03 (13.8%), along with three cases of minor genotypes (4.6%). For 43 pregnant women with the RHD*01N.01 or RHD*01N.03 alleles, qPCR on maternal cell-free DNA yielded a 98.5% (42/43) accuracy rate and 100% successful prediction rate. High-throughput sequencing was successfully used to predict fetal RhD phenotypes for 13 pregnant women with RHD(1227G>A).

CONCLUSION

On the basis of maternal RHD genotyping, fetal genotyping through qPCR or high-throughput sequencing can improve the accuracy and success rate of prenatal fetal RhD phenotype prediction among Chinese pregnant women. It plays a potential role in guiding anti-D prophylaxis and pregnancy management in Chinese pregnant women.

Hemolytic disease of the fetus and newborn: rapid review of postnatal care and outcomes

BACKGROUND

Advances in postnatal care for hemolytic disease of the fetus and newborn (HDFN) have occurred over the past decades, but little is known regarding the frequency of postnatal treatment and the clinical outcomes of affected neonates. Most studies reporting on HDFN originate from high-income countries or relatively large centers, but important differences between centers and countries may exist due to differences in prevalence and available treatment options. We therefore aimed to evaluate the postnatal treatment landscape and clinical outcomes in neonates with Rhesus factor D (Rh(D))- and/or K-mediated HDFN and to provide recommendations for future research.

METHODS

We conducted a rapid literature review of case reports and series, observational retrospective and prospective cohort studies, and trials describing pregnancies or children affected by Rh(D)- or K-mediated HDFN published between 2005 and 2021. Information relevant to the treatment of HDFN and clinical outcomes was extracted. Medline, ClinicalTrials.gov and EMBASE were searched for relevant studies by two independent reviewers through title/abstract and full-text screening. Two independent reviewers extracted data and assessed methodological quality of included studies.

RESULTS

Forty-three studies reporting postnatal data were included. The median frequency of exchange transfusions was 6.0% [interquartile range (IQR): 0.0-20.0] in K-mediated HDFN and 26.5% [IQR: 18.0-42.9] in Rh(D)-mediated HDFN. The median use of simple red blood cell transfusions in K-mediated HDFN was 50.0% [IQR: 25.0-56.0] and 60.0% [IQR: 20.0-72.0] in Rh(D)-mediated HDFN. Large differences in transfusion rates were found between centers. Neonatal mortality amongst cases treated with intrauterine transfusion(s) was 1.2% [IQR: 0-4.4]. Guidelines and thresholds for exchange transfusions and simple RBC transfusions were reported in 50% of studies.

CONCLUSION

Most included studies were from middle- to high-income countries. No studies with a higher level of evidence from centers in low-income countries were available. We noted a shortage and inconsistency in the reporting of relevant data and provide recommendations for future reports. Although large variations between studies was found and information was often missing, analysis showed that the postnatal burden of HDFN, including need for neonatal interventions, remains high.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO 2021 CRD42021234940. Available from:  https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021234940 .

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.

Hemolytic disease of the fetus and newborn: systematic literature review of the antenatal landscape

BACKGROUND

Prevention of pregnancy-related alloimmunization and the management of hemolytic disease of the fetus and newborn (HDFN) has significantly improved over the past decades. Considering improvements in HDFN care, the objectives of this systematic literature review were to assess the prenatal treatment landscape and outcomes of Rh(D)- and K-mediated HDFN in mothers and fetuses, to identify the burden of disease, to identify evidence gaps in the literature, and to provide recommendations for future research.

METHODS

We performed a systematic search on MEDLINE, EMBASE and clinicaltrials.gov. Observational studies, trials, modelling studies, systematic reviews of cohort studies, and case reports and series of women and/or their fetus with HDFN caused by Rhesus (Rh)D or Kell alloimmunization. Extracted data included prevalence; treatment patterns; clinical outcomes; treatment efficacy; and mortality.

RESULTS

We identified 2,541 articles. After excluding 2,482 articles and adding 1 article from screening systematic reviews, 60 articles were selected. Most abstracted data were from case reports and case series. Prevalence was 0.047% and 0.006% for Rh(D)- and K-mediated HDFN, respectively. Most commonly reported antenatal treatment was intrauterine transfusion (IUT; median frequency [interquartile range]: 13.0% [7.2-66.0]). Average gestational age at first IUT ranged between 25 and 27 weeks. weeks. This timing is early and carries risks, which were observed in outcomes associated with IUTs. The rate of hydrops fetalis among pregnancies with Rh(D)-mediated HDFN treated with IUT was 14.8% (range, 0-50%) and 39.2% in K-mediated HDFN. Overall mean ± SD fetal mortality rate that was found to be 19.8%±29.4% across 19 studies. Mean gestational age at birth ranged between 34 and 36 weeks.

CONCLUSION

These findings corroborate the rareness of HDFN and frequently needed intrauterine transfusion with inherent risks, and most births occur at a late preterm gestational age. We identified several evidence gaps providing opportunities for future studies.

Rhesus Negativity Prevalence and Neonatal Outcomes among Pregnant Women Delivered at Bule Hora University Teaching Hospital, West Guji Zone, South Ethiopia

Background

Rh incompatibility has been an important cause of severe neonatal hyperbilirubinemia, hydrops fetalis, and stillbirth. Among those outcomes, neonatal jaundice is the most common problem.

Objective

The study is assessed the prevalence of Rhesus (Rh) negativity and neonatal outcomes among pregnant women who delivered at Bule Hora University Teaching Hospital over a 5-year period from January 2017 to December 31, 2022.

Methods

A retrospective study was conducted on 110 women who delivered at Bule Hora University Teaching Hospital (BHUTH) from January 2017 to December 31, 2021. The complete data of the mother's and neonates' status were extracted from the registration book of the hospital using checklists. The data were double entered using EpiData version 3 and exported to the Statistical Package for Social Sciences (SPSS) version 26 for analysis. Descriptive statistics to determine prevalence and frequencies were used to describe the study population in relation to relevant variables, and the results are presented in tables and charts.

Results

The study shows that the prevalence of Rh D-negative among women who delivered was 6.4% [95% CI: 1.83,10.98]. Among Rh-negative women, 1 (25%) of blood group AB, 3 (6.5%) of blood group O, and 2 (6.1%) of blood group A were Rh-D negative. The distributions of O, A, B, and AB blood groups among pregnant women who delivered this hospital were 41.8%, 30%, 24.6%, and 3.6%, respectively. Out of neonates born to Rh-negative women, 1 (14.3%) was born with jaundice. Of women who delivered at BHUT hospital, 61 (55.5%) did not have a previous delivery, 7 (6.4%) had a previous abortion, 5 (4.5%) stillbirth, 1 (0.9) died after birth, 4 (3.6%) had a birth child weight less than 2.6 kg.

Conclusion

The study revealed that the prevalence of Rh-negative was comparable with finding of different similar studies. To reduce Rh incompatibility-related HDN, the government should educate mothers and encourage them as they follow ANC facilities and after delivery to health facilities.

Immunoglobulin for hemolytic jaundice in Japan: A retrospective survey

BACKGROUND

Intravenous immunoglobulin G (IVIG) is used to treat blood-type incompatibility hemolytic disease of newborns (BTHDN). Although IVIG's efficacy for treating BTHDN has been challenged, as an updated systematic review suggests, IVIG could significantly reduce exchange transfusions. We conducted a mail-in questionnaire survey to ascertain actual use of IVIG for BTHDN in Japan.

METHODS

The survey, conducted in 2014, included infants born between January 1, 2009, and December 31, 2013. Questionnaires were sent to the heads of neonatal intensive care units (NICUs) at perinatal centers of the Japan Neonatologist Association.

RESULTS

A total of 195 centers (64.6%) responded to the questionnaire. During the study period, 170 centers (87.2%) reported incidences of BTHDN. Among these centers, there were 1726 diagnosed cases of BTHDN in neonates. Of these cases, 419 infants were treated with IVIG in 127 centers, representing approximately 74.7% of all centers. After the exclusion of cases with missing data and those where consent for data usage was not obtained, a total 916 infants were included in this study. Of these, 219 (23.9%) were treated with IVIG after phototherapy, and 187 (20.4%) of these infants did not require further blood exchange transfusion. The IVIG dosages ranged from 40 to 1200 mg/kg/dose, but the majority were between 500 and 1000 mg/kg/dose, with a median of 800 mg/kg/dose. About 20% of the infants treated with IVIG showed late-onset anemia and required treatment. Adverse events were reported in less than 1% of infants.

CONCLUSIONS

For the treatment of BTHDN, IVIG administration was widely used in NICUs in Japan without severe adverse events.

Hemolytic Disease of the Newborn: A Review of Current Trends and Prospects

Hemolytic disease of the newborn (HDN), also known as Erythroblastosis fetalis, is a hemolytic condition that predominantly affects rhesus-positive fetuses and infants born to rhesus-negative mothers. The pathophysiology of HDN begins with maternal antibodies attacking fetal red blood cells following alloimmunization due to rhesus or ABO incompatibility between the maternal and fetal blood. Previously, HDN was known to cause fetal death in 1% of all pregnancies, but with the advent of immunoprophylactic therapies, the condition can be currently fairly well managed with fewer complications if diagnosed early. Diagnosis calls for extensive history taking, physical examination, serological studies, and imaging modalities such as pelvic ultrasound scans. To prevent the disease, earlier intravenous immunoglobulin (IVIG) should be given to pregnant Rh- women who have not been sensitized. It is also vital to understand prospective complications such as severe hyperbilirubinemia and develop appropriate remedies. Because of its great incidence and nature, HDN has been thoroughly explored, and more studies are being conducted each year, revealing new insights about the condition. This review covers the disorder's etiology, diagnosis, and management, including the most current findings as of 2021, as well as trends and prospects, to help in future research and evidence-based medical practice.