Hemolytic Disease of the Newborn Due to Anti-c Isoimmunization: A Case Report

How clinically important are non-D Rh antibodies?

INTRODUCTION

The advent of RhD immunoglobulin prophylaxis to prevent maternal RhD alloimmunization has reduced the incidence of this condition and its associated poor outcomes. Consequently, non-D Rh antibodies now account for a greater proportion of alloimmunized pregnancies. These antibodies have been the subject of comparatively little research. This study investigated the incidence and clinical outcome of pregnancies affected by non-D Rh alloimmunization at an Australian tertiary maternity service.

MATERIAL AND METHODS

This was a retrospective study of all pregnancies with non-D Rh antibodies (namely anti-C, -E, -c, -e, -C^w as well as the compound antibodies anti-CD, -cE and -ce) managed at the Royal Women's Hospital, Victoria, Australia, from 2009 to 2013 inclusive. Information collected included maternal demographics, details of the antibodies, course of the pregnancy and neonatal outcomes.

RESULTS

During the study period, 115 non-D Rh alloimmunized pregnancies were identified in 102 mothers. Forty-nine pregnancies reached the critical titer (> 16) from non-D Rh alone and 11 fetuses received intrauterine red blood cell transfusion. Labor was induced or cesarean section performed in 38 cases. Forty-three neonates were admitted to the special care nursery and 59 received phototherapy. Nine received treatment for anemia and 10 neonates received intravenous immunoglobulin.

CONCLUSIONS

Non-D Rh alloimmunization is a relatively uncommon complication of pregnancy, occurring in only .33% of pregnancies in the study period. It can lead to significant fetal/neonatal morbidity (and may lead to mortality). The most severe outcomes (including perinatal deaths) were mostly associated with the compound antibodies anti-CD and anti-cE, or a non-D Rh antibody in conjunction with anti-D.

Sequence diversity of the Rh blood group system in Basques

Basques show specific cultural, demographic, and genetic characteristics that have placed them as an isolated and unique population within Europe, such as their non-Indo-European language, Euskara. They have historically lived along the Western Pyrenees, between Spain and France, in one of the most important European glacial refugia during the Last Glacial Maximum. The most striking genetic characteristic is their highest frequency of the RhD blood group negative allele, a variant related to the hemolytic disease of the newborn. Both demographic and adaptive processes have been suggested as possible causes of the high frequency of RhD negative in Basques, but neither hypothesis has been clearly demonstrated. While previous studies on the Rh system in Basques have been mostly focused on serological and genotyping diversity, in this work we analyze genotyping and next generation sequencing data in order to provide a general framework of the genetic scenario of the system in Basques. In particular, we genotyped the most relevant variants of the system (D/d, E/e, and C/c), and sequenced three ~6 kb flanking regions surrounding the Rh genes in Basques and also in other populations for comparison. Our results are in agreement with previous studies, with Basques presenting the highest frequency of the RHD deletion (47.2%). Haplotype analyses of D/d, E/e, and C/c variants confirmed an association between the RhC allele, previously suggested to be under positive selection, and the RhD positive variant in non-sub-Saharan populations, including Basques. We also found extreme differentiation for the C/c variant when comparing sub-Saharan to non-sub-Saharan populations.

ABO hemolytic disease of the fetus and newborn: thirteen years of data after implementing a universal bilirubin screening and management program

OBJECTIVE

ABO hemolytic disease occurs among neonates with blood groups A or B delivered to group O women. Extreme neonatal hyperbilirubinemia due to ABO disease has been reported, but its frequency is not well known. We sought to determine the odds of developing severe ABO hemolytic disease in the 13 years since adopting universal bilirubin screening/management in the Intermountain Healthcare system.

STUDY DESIGN

We conducted a retrospective analysis of neonates born between 2004 and 2016, defining "severe hemolytic disease" as; (1) total serum bilirubin (TSB) >25 mg/dL, or (2) hospital readmission for jaundice, or (3) bilirubin encephalopathy. Neonates born to group O (+) mothers were included and considered either; (1) Controls (not at risk for ABO disease because they were group O), (2) Study subjects (at risk for ABO disease because they were group A or B).

RESULTS

Of 400,531 live births, 47% were to group O women; 86% of whom were group O (+). Overall, 42,529 (27%) neonates born to group O (+) women had their blood group determined; 29,729 (68%) were O, 10,682 (25%) A, and 3109 (7%) B. Peak TSBs during the first 10 days were higher in group A (11.0 ± 4.2 mg/dL) and B (11.5 ± 4.3) than group O neonates (10.3 ± 4.1). However the relative risks of a TSB ≥25 mg/dL, readmission for jaundice, or kernicterus, were the same in the control vs. study groups.

CONCLUSIONS

In our health system, severe hemolytic disease in neonates born to group O (+) woman is not more likely in group A or B neonates than in controls (group O). We recognize that in other practices, particularly those who do not have a universal bilirubin screening/management program, ABO hemolytic disease severity might be different than in our system.

Frequency of Red Cell Alloantibodies in Pregnant Females of Navsari District: An Experience that Favours Inclusion of Screening for Irregular Erythrocyte Antibody in Routine Antenatal Testing Profile

Background

Alloimmunisation due to irregular erythrocyte antibodies is a recognised cause of hemolytic disease of the fetus and newborn (HDFN). Prior knowledge of red cell alloimmunisation in pregnant females guides the obstetrician to monitor the foetus for HDFN and if required for appropriated intervention. As limited data are available on prevalence of red cell alloimmunisation in pregnant females in India, the current study was carried out to know the prevalence of red cell alloimmunisation in pregnant females coming at our laboratory.

Methods

Screening for irregular erythrocyte antibodies was performed in 1960 pregnant females after obtaining informed consent between June 2015 and June 2016. MatrixTM screening and identification reagent red cells from Tulip Diagnostics (P) Ltd were used, and column agglutination technique was employed as a method for the test.

Results

Twenty antibodies (all of single specificity) were detected in 1960 samples giving a prevalence rate of alloimmunisation of 1.02%. Out of the 20 antibodies, 18 were identified to be anti-D, 1 was anti-c and 1 antibody was anti-H. The results obtained were then compared with those reported in the literature.

Conclusion

Red cell alloimmunisation is not uncommonly observed in pregnant females; the information gained can help the obstetrician to identify high-risk cases to timely start antenatal and post-natal treatment. Obstetricians should request screening for irregular red cell antibody desirably in all pregnant females; however, if limiting factors are there, it should be done at least in select group of pregnant females having bad obstetric history.

Anti-c (Little c) IgM: An Uncommonly Observed but Expected Phenomenon

The c-antigen (little c) is part of the Rh blood group system and is found in approximately 80% of the United States population. Anti-c antibody develops in individuals sensitized through previous exposure and is associated with acute and delayed hemolytic transfusion reactions as well as hemolytic disease of the newborn (HDN). Most antibodies produced against Rh antigens are of the immunoglobulin (Ig) G type. We present a case of anti-c in a 30-year-old white woman who was gravida 2 para 1 (G2P1), whose laboratory workup at the time of admission for delivery suggests recent exposure and seroconversion in the latter part of her pregnancy, with evidence of the expected but rarely demonstrated presence of anti-c IgM and IgG.