Iron Overload and Anemia in Rhesus Hemolytic Disease of Newborn: A Prospective Observational Study

This study assessed the prevalence of iron overload in infants born to Rh isoimmunized mothers. Infants born to Rh isoimmunized mothers with Indirect Coomb's Test (ICT) titers ≥1:16 were prospectively enrolled and followed until 3 mo. Hemoglobin and serum ferritin were estimated at birth and 3 mo of age. The outcomes were the incidence of iron overload (at birth and 3 mo), anemia, and the need for transfusions in the first 3 mo. Seventy-four infants were enrolled, nearly half receiving intrauterine transfusion (IUT). Sixty (82.2%) had hyperferritinemia at birth. The median (1st, 3rd quartile) ferritin levels were 456 (321, 631) μg/L. Infants who received IUTs had significantly higher serum ferritin levels at birth. Fifty-one (76.1%) infants had hyperferritinemia at 3 mo. Over three months of follow-up, 53 (71.6%) infants had anemia, of which 33 (48.5%) required packed red blood cells (PRBC) transfusion. These findings suggest that iron overload is common in these infants in the first 3 mo.

Clinical significances and distribution of unexpected antibodies found in infants

INTRODUCTION

The unexpected antibody test is an essential for ensuring the safety of blood transfusions. In infants, different pre-transfusion tests and transfusion strategies are needed due to their immature antigen/antibody system. This study aims to analyze the pattern of unexpected antibodies and their clinical significance in infants.

METHODS

A retrospective analysis was conducted on the results of unexpected antibody identification tests performed on infants under one year of age at Asan Medical Center from 1999 to 2022. Patients' unexpected antibody identification test results and clinical information were investigated. The results of unexpected antibody identification and phenotype of each patient's mother were collected.

RESULTS

45 cases of antibody results were studied. 25 cases were found in infants under 4 months of age, and 18 cases (76%) were associated with hemolytic disease of the fetus and newborn (HDFN). The most common unexpected antibody in infants was anti-M (17 cases). There was one case of severe HDFN caused by anti-M. In 10 cases, anti-E and anti-c were found together, and 9 of these cases were associated with HDFN. There were four cases with a history of previous transfusion.

CONCLUSIONS

Non-ABO antibodies found in infants showed a different pattern compared to adults. Interpreting unexpected antibody tests in infants, it is important to consider the clinical status of the infant and the test results of the mother, due to possibility of HDFN. To our knowledge, this is the first study to reveal the distribution and clinical significances of unexpected antibodies found in infants in Korea.

Early-onset hypoproliferative anemia in an intrauterine-transfused neonate with severe Rh hemolytic disease

A fetus with features of hydrops was given intra-uterine transfusion at 27 weeks and 31 weeks of gestation. Mother had been alloimmunized with anti-D and anti-C antibodies. At birth, laboratory investigations revealed bone marrow suppression along with features of hemolytic anemia. The neonate was started on a combination of phototherapy and intravenous immunoglobulin. During the course, the neonate was transfused with one unit of packed red cells (top-up transfusion). Neonatal hyperbilirubinemia responded to phototherapy and the bone marrow activity spontaneously resumed after 3 weeks of life. In neonates with anemia at birth who have history of multiple intra-uterine transfusions, early-onset hypoproliferative anemia should be considered.

Laboratory Monitoring of Mother, Fetus, and Newborn in Hemolytic Disease of Fetus and Newborn

Background

Laboratory monitoring of mother, fetus, and newborn in hemolytic disease of fetus and newborn (HDFN) aims to guide clinicians and the immunized women to focus on the most serious problems of alloimmunization and thus minimize the consequences of HDFN in general and of anti-D in particular. Here, we present the current approach of laboratory screening and testing for prevention and monitoring of HDFN at the Copenhagen University Hospital in Denmark.

Summary

All pregnant women are typed and screened in the 1st trimester. This serves to identify the RhD-negative pregnant women who at gestational age (GA) of 25 weeks are offered a second screen test and a non-invasive fetal RhD prediction. At GA 29 weeks, and again after delivery, non-immunized RhD-negative women carrying an RhD-positive fetus are offered Rh immunoglobulin. If the 1st trimester screen reveals an alloantibody, antenatal investigation is initiated. This also includes RhD-positive women with alloantibodies. Specificity and titer are determined, the fetal phenotype is predicted by non-invasive genotyping based on cell-free DNA (RhD, K, Rhc, RhC, RhE, ABO), and serial monitoring of titer commences. Based on titers and specificity, monitoring with serial peak systolic velocity measurements in the fetal middle cerebral artery to detect anemia will take place. Intrauterine transfusion is given when fetal anemia is suspected. Monitoring of the newborn by titer and survival of fetal red blood cells by flow cytometry will help predict the length of the recovery of the newborn.

Prenatal RHD genotyping in Croatia: preliminary results

OBJECTIVES

Croatian Institute of Transfusion Medicine (CITM) implemented non-invasive fetal RHD genotyping as a request for targeted antenatal anti-D prophylaxis. The diagnostic performance of in-house RT-PCR method for fetal RHD genotyping and preliminary results are analyzed.

MATERIALS AND METHODS

Evaluation included results of RHD genotyping for 205 RhD negative pregnant women, 12-36th week of gestation, whose samples were received in period between 2015 and 2020. QIAsymphony SP DSP Virus Midi Kit was used for cffDNA extraction on QIAsymphony SP platform (Qiagen, Germany). Fragments of RHD exons 7 and 10 and later exon 5 were RT-PCR amplified. As internal controls, amplification of SRY gene or RASSF1A fragment and β-actin genes digested with BsTUI were used.

RESULTS

We identified 70.72% (145/205) positive and 28.78% (59/205) negative fetal RHD genotypes. We had one inconclusive result (0.50%) due to the interference of maternal DNA with variant genotype RHD*09.02.00/01/*01N.01. When compared to newborns RhD phenotypes, no false negative and three false positive results (3/199, 1.50%) were observed. The test yielded 100% sensitivity and 95.08% specificity, while diagnostic accuracy was 98.48%. We were able to determine one case of fetal variant genotype RHD*04.04/*01N.01 inherited from the father. The negative and positive predictive test values were 100% and 97.86%, respectively.

CONCLUSION

Automated cffDNA extraction and RT-PCR amplification of fetal RHD exons 5,7,10 and fragments of SRY, RASSF1A genes represents highly reliable system for determining fetal RHD status which enables targeted antenatal anti-D prophylaxis. To obtain high specificity of cffDNA extraction, strict and thoroughly cleaning procedures are required.

Clinical Significance of Rare Maternal Anti Jka Antibody

We hereby report a rare case of HDFN because of antibody to Kidd (Jk) blood group system-anti Jka. An EDTA sample of a baby along with mother's sample was received in the Department for Direct Antiglobulin Test (DAT) alongwith blood requisition for double volume exchange transfusion. On blood grouping, baby's and mother's blood group was found to be B Rh D positive. DAT with polyspecific anti human globulin (AHG) was positive. Screening of mother's serum for irregular antibodies showed anti-Jka antibody. AHG phase titers using tube technique were 1:64. Mother was found to be Jka antigen negative; father and neonate were found to be Jka antigenpositive. Antibody was observed to be of IgG type on Dithiothreitol treatment. Baby had total serum bilirubin of 20.5 mg/dl on day 3 of life and phototherapy was started. Exchange transfusion was not required in the baby. The present case emphasises the significance of minor blood group antigens other than Rh blood group system as a cause of HDFN. Although HDFN due to Jk antibodies is rare, however, the clinician must be aware of the occurrence of these antibodies as they can lead to severe HDFN and persistent anemia in the infant.