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Background and Objectives: To evaluate the severity of haemolytic disease of the foetus and newborn (HDFN) in subsequent pregnancies with RhD immunization and to identify predictive factors for severe disease., Materials and Methods: Nationwide prospective cohort study, including all pregnant women with RhD antibodies. All women with at least two pregnancies with RhD antibodies and RhD-positive foetuses were selected. The main outcome measure was the severity of HDFN in the first and subsequent pregnancy at risk. A subgroup analysis was performed for the group of women where RhD antibodies developed after giving birth to an RhD-positive child and thus after receiving anti-D at least twice (group A) or during the first pregnancy at risk for immunization (group B)., Results: Sixty-two RhD immunized women with a total of 150 RhD-positive children were included. The severity of HDFN increased for the whole group significantly in the subsequent pregnancy (p < 0.001), although it remained equal or even decreased in 44% of women. When antibodies were already detected at first trimester screening in the first immunized pregnancy, after giving birth to an RhD-positive child (group A), severe HDFN in the next pregnancy was uncommon (22%). Especially when no therapy or only non-intensive phototherapy was indicated during the first immunized pregnancy (6%) or if the antibody-dependent cell-mediated cytotoxicity result remained <10%. Contrarily, women with a negative first trimester screening and RhD antibodies detected later during the first pregnancy of an RhD-positive child (group B), often before they had ever received anti-D prophylaxis, were most prone for severe disease in a subsequent pregnancy (48%)., Conclusion: RhD-mediated HDFN in a subsequent pregnancy is generally more severe than in the first pregnancy at risk and can be estimated using moment of antibody detection and severity in the first immunized pregnancy. Women developing antibodies in their first pregnancy of an RhD-positive child are at highest risk of severe disease in the next pregnancy., (© 2024 The Authors. Vox Sanguinis published by John Wiley & Sons Ltd on behalf of International Society of Blood Transfusion.)

Background and Objectives: Despite advances in the prevention of rhesus (Rh)(D) alloimmunization, alloantibodies to Rh(D) and non-Rh(D) red blood cell antigens continue to be detected in ∼4% of US pregnancies and can result in hemolytic disease of the fetus and newborn (HDFN). Recent reports on HDFN lack granularity and are unable to provide antibody-specific outcomes. The objective of this study was to calculate the frequency of alloimmunization in our large hospital system and summarize the outcomes based on antibody specificity, titer, and other clinical factors., Methods: We identified all births in a 6-year period after a positive red blood cell antibody screen result during pregnancy and summarized their characteristics and outcomes., Results: A total of 707 neonates were born after a positive maternal antibody screen result (3.0/1000 live births). In 31 (4%), the positive screen result was due to rhesus immune globulin alone. Of the 676 neonates exposed to alloantibodies, the direct antibody test (DAT) result was positive, showing antigen-positivity and evidence of HDFN in 37% of those tested. Neonatal disease was most severe with DAT-positive anti-Rh antibodies (c, C, D, e, E). All neonatal red blood cell transfusions (15) and exchange transfusions (6) were due to anti-Rh alloimmunization. No neonates born to mothers with anti-M, anti-S, anti-Duffy, anti-Kidd A, or anti-Lewis required NICU admission for hyperbilirubinemia or transfusion., Conclusions: Alloimmunization to Rh-group antibodies continues to cause a majority of the severe HDFN cases in our hospital system. In neonates born to alloimmunized mothers, a positive DAT result revealing antigen-positivity is the best predictor of anemia and hyperbilirubinemia., (Copyright © 2024 by the American Academy of Pediatrics.)

Background: We report an obstetric case involving an RhD-positive woman who had developed a red blood cell (RBC) antibody that was not detected until after delivery of a newborn, who presented with a positive direct antiglobulin test result. Immunohematology studies suggested that the maternal antibody was directed against a low-prevalence antigen on the paternal and newborn RBCs., Results: Comprehensive blood group profiling by targeted exome sequencing revealed a novel nonsynonymous single nucleotide variant (SNV) RHCE c.486C>G (GenBank MZ326705) on the RHCE*Ce allele, for both the father and newborn. A subsequent genomic-based study to profile blood groups in an Indigenous Australian population revealed the same SNV in 2 of 247 individuals. Serology testing showed that the maternal antibody reacted specifically with RBCs from these two individuals., Discussion: The maternal antibody was directed against a novel antigen in the Rh blood group system arising from an RHCE c.486C>G variant on the RHCE*Ce allele linked to RHD*01. The variant predicts a p.Asn162Lys change on the RhCE protein and has been registered as the 56th antigen in the Rh system, ISBT RH 004063., Conclusion: This antibody was of clinical significance, resulting in a mild to moderate hemolytic disease of the fetus and newborn (HDFN). In the past, the cause of such HDFN cases may have remained unresolved. Genomic sequencing combined with population studies now assists in resolving such cases. Further population studies have potential to inform the need to design population-specific red cell antibody typing panels for antibody screening in the Australian population., (© 2022 AABB.)

Maternal alloantibodies directed against fetal red blood cell (RBC) antigens may cause potentially life-threatening haemolytic disease of the fetus and newborn (HDFN). Dutch transfusion guidelines therefore prescribe preventive cEK matching for all (pre-)fertile females. To quantify the impact of cEK matching, we compared overall and antigen-specific cumulative RBC alloimmunisation incidences in females and males aged <45 years. Among a multicentre cohort comprised of patients who received their first and subsequent RBC unit between 2005 and 2019, first-formed RBC alloantibodies were detected in 47 of 2998 (1·6%) females and 49 of 2507 (2·0%) males. Comparing females and males, overall alloimmunisation incidences were comparable (3·1% [95% confidence interval (CI) 2·1-4·4] versus 3·5% (95% CI 2·4-4·9, P = 0·853) after 10 units transfused). However, cEK alloimmunisation incidences were significantly lower among females (0·6% (95% CI 0·3-1.5) versus 2·2% (95% CI 1·5-3·4, P = 0·001) after 10 units transfused). Yet, despite cEK-matching guidelines being in effect, 6·5%, 3·6% and 0·2% of all RBC units remained mismatched for c, E or K antigens respectively. Most of these mismatches were almost always due to emergency settings. Even though cEK alloimmunisation was not prevented completely, implementation of cEK matching resulted in an alloantigen-exposure risk reduction of up to 98%., (© 2021 The Authors. British Journal of Haematology published by British Society for Haematology and John Wiley & Sons Ltd.)

Background: Alloimmunization can impact both the fetus and neonate., Study Objectives: (a) calculate the incidence of clinically significant RBC isoimmunization during pregnancy, (b) review maternal management and neonatal outcomes, (c) assess the value of prenatal and postnatal serological testing in predicting neonatal outcomes., Study Design and Methods: A retrospective audit of consecutive alloimmunized pregnancies was conducted. Data collected included demographics, clinical outcomes, and laboratory results. Outcomes included: incidence of alloimmunization; outcomes for neonates with and without the cognate antigen; and sensitivity and specificity of antibody titration testing in predicting hemolytic disease of the fetus and newborn (HDFN)., Results: Over 6 years, 128 pregnant women (0.4%) were alloimmunized with 162 alloantibodies; anti-E was the most common alloantibody (51/162; 31%). Intrauterine transfusions (IUTs) were employed in 2 (3%) of 71 mothers of cognate antigen positive (CoAg+) neonates. Of 74 CoAg+ neonates, 58% required observation alone, 23% intensive phototherapy, 9% top up transfusion, and 3% exchange transfusion; no fetal or neonatal deaths occurred. HDFN was diagnosed in 28% (21/74) of neonates; anti-D was the most common cause. The sensitivity and specificity of the critical gel titer >32 in predicting HDFN were 76% and 75%, respectively (negative predictive value 95%; positive predictive value 36%). The sensitivity and specificity of a positive direct antiglobulin test (DAT) in predicting HDFN were 90% and 58%, respectively (NPV 97%; PPV 29%)., Conclusion: Morbidity and mortality related to HDFN was low; most alloimmunized pregnancies needed minimal intervention. Titers of >32 by gel warrant additional monitoring during pregnancy., (© 2020 AABB.)

In the mid-20th century, Hemolytic Disease of the Fetus and Newborn, caused by maternal alloimmunization to the Rh(D) blood group antigen expressed by fetal red blood cells (i.e., "Rh disease"), was a major cause of fetal and neonatal morbidity and mortality. However, with the regulatory approval, in 1968, of IgG anti-Rh(D) immunoprophylaxis to prevent maternal sensitization, the prospect of eradicating Rh disease was at hand. Indeed, the combination of antenatal and post-partum immunoprophylaxis is ~99% effective at preventing maternal sensitization to Rh(D). To investigate global compliance with this therapeutic intervention, we used an epidemiological approach to estimate the current annual number of pregnancies worldwide involving an Rh(D)-negative mother and an Rh(D)-positive fetus. The annual number of doses of anti-Rh(D) IgG required for successful immunoprophylaxis for these cases was then calculated and compared with an estimate of the annual number of doses of anti-Rh(D) produced and provided worldwide. Our results suggest that ~50% of the women around the world who require this type of immunoprophylaxis do not receive it, presumably due to a lack of awareness, availability, and/or affordability, thereby putting hundreds of thousands of fetuses and neonates at risk for Rh disease each year. The global failure to provide this generally acknowledged standard-of-care to prevent Rh disease, even 50 years after its availability, contributes to an enormous, continuing burden of fetal and neonatal disease and provides a critically important challenge to the international health care system., Competing Interests: Dr. Spitalnik has read the journal's policy and the authors of this manuscript have the following competing interests: he is a member of the Scientific Advisory Board of Hemanext, Inc. and a consultant for Tioma, Inc. However, neither of these competing interests are relevant to the content of the submitted manuscript. Valeria Pegoraro and Duccio Urbinati are employees of IQVIA Solutions Italy S.r.l. However, none of these competing interests are relevant to the content of the submitted manuscript. The other authors have declared that no competing interests exist.

Anti-G is commonly present with anti-D and anti-C and can confuse serological investigations. The differentiation of anti-G from anti-D and anti-C is particularly essential for the accurate diagnosis of hemolytic disease of the fetus and newborn (HDFN) and appropriate administration of anti-D immunoglobulin prophylaxis in Rhesus (Rh) negative women. We reported a rare case of anti-G together with anti-D and anti-C in a pregnant woman and her female neonate. The titers of IgG anti-D, anti-C, and anti-G in the woman were 256, 128, and 32, respectively. While the titers of IgG anti-D, anti-C, and anti-G in the neonate were 16, 8, and 4, respectively. The neonate experienced mild HDFN and only received phototherapy during hospitalization. This report discusses the diagnostic strategy and clinical significance of differentiating anti-G from anti-D and anti-C., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

The rare blood phenotype D-- is characterized by the absence of RhCcEe antigens. Women with this blood type who have experienced previous pregnancies may produce anti-Rh17 antibodies, which may cause severe fetal hemolytic anemia or fetal death in subsequent pregnancies. We report successful management of a pregnancy associated with fetal hemolytic disease owing to high titers of anti-Rh17 (1:4096) in a woman with a history of a pregnancy with fetal hydrops and intrauterine fetal death. During her second pregnancy, she received two sets of plasma exchange (PE) per week from weeks 12 till 20. Intrauterine transfusions (IUTs) were performed at 26, 27, 29, and 31 weeks. A male infant was born at 32 weeks and 4 days by normal vaginal delivery, with a birth weight of 1916 g (+ 0.16 SD). He received an exchange transfusion on day 0, immunoglobulin (intravenous immunoglobulin: 1 g/kg) on days 0 and 1, and photo therapy from days 0 to 6. He showed normal development without neurological abnormality and was discharged from the hospital on day 36. We successfully prevented complications caused by the presence of anti-Rh17 antibodies in the mother during pregnancy. The IUT and maternal PE may have promoted this favorable outcome.

Alloimmunization to red blood cell (RBC) antigens represents a challenge for physicians caring for women of child bearing potential. Exposure to non-self RBC antigens may occur during transfusion or pregnancy leading to the development of antibodies. If a subsequent fetus bears that antigen, maternal antibodies may attack the fetal red blood cells causing red cell destruction and clinically significant hemolytic disease of the fetus and newborn (HDFN). In the most severe cases, HDFN may result in intrauterine fetal demise due to high output cardiac failure, effusions and ascites, known as "hydrops fetalis". This article reviews strategies for management and prevention of RBC alloimmunization in women of child bearing potential., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Prenatal detection of the fetal RHD status can be useful in the management of RhD incompatibility to identify fetuses at risk of hemolytic disease. Hemolytic disease causes morbidity and mortality of the fetus in the neonatal period. The routine use of antenatal and postnatal anti-D prophylaxis has reduced the incidence of hemolytic disease of the fetus and newborn. This study describe the detection of fetal RhD antigens in blood of RhD negative pregnant women using a nanopolymer coated electrochemical biosensor for medical diagnosis. Cell free fetal DNA in maternal plasma was also used to genotyping fetal RHD status using multiplex real-time PCR. Twenty-six RhD negative pregnant women in different gestational ages were included in the study. RhD positive fetal antibodies detected with a developed biosensor in maternal blood of RhD negative mothers. The electrochemical measurements were performed on a PalmSens potentiostat, and corundum ceramic based screen printed gold electrode combined with the reference Ag/AgCl electrode, and the auxiliary Au/Pd (98/2%) electrode. Fetal RHD genotyping performed using fluorescence-based multiplex real-time PCR exons 5 and 7 of the RHD gene. The fetal RHD status of 26 RhD negative cases were detected 21 as RhD positive and 5 as RhD negative with electrochemical biosensor. Fetal RHD status confirmed with extracted fetal DNA in maternal plasma using multiplex real-time PCR RHD genotyping and by serological test after delivery. The new method for fetal RhD detection in early pregnancy is useful and can be carry out rapidly in clinical diagnosis. Using automated biosensors are reproducible, quick and results can be generated within a few minutes compared to noninvasive fetal RHD genotyping from maternal plasma with real-time PCR-based techniques. We suggest the biosensor techniques could become an alternative part of fetal RHD genotyping from maternal plasma as a prenatal screening in the management of RhD incompatibility., Competing Interests: The authors have declared that no competing interests exist.

Background: RhIG prophylaxis for D- pregnant women prevents hemolytic disease of the newborn and typically depends on results of serologic D typing. Interpretation and follow-up of weak D serology is variable. Recent recommendations promote genotyping for RHD status determination in those with weak D serology. Canadian Blood Services performs comprehensive serologic prenatal testing in four provinces. Genotyping is used to determine D typing in patients with weak D., Study Design and Methods: A serologic algorithm identified which patients require genotyping for RHD determination. Genotyping was performed on one of two commercially available platforms., Results: Only 0.4% of D- patients met criteria for genotyping. Sixty-one percent were weak D Type 1, 2, or 3. Thirty percent had a partial or weak D other than Type 1, 2, or 3. Eleven had variants which remained unresolved. Seventeen were D+ and four were D-., Conclusions: Genotyping of patients with weak D serology led to an identified genotype in most patients. RhIG administration was avoided in 66% who were weak D Type 1, 2, or 3 or were D+. The use of a serologic algorithm to select patients for RHD genotyping identifies a majority of patients with weak D types not at risk for alloimmunization. This approach limits the number of genotyping investigations and the cost of providing classification for weak D types., (© 2016 AABB.)

Objective: To evaluate the effect of red blood cell (RBC) antibody screening in the 27th week of pregnancy in Rhc-negative women, on detection of alloimmunisation, undetected at first trimester screening ('late' alloimmunisation), and subsequent haemolytic disease of the fetus and newborn (HDFN), to assess risk factors for late alloimmunisation., Design: Prospective cohort and nested case-control study., Setting: The Netherlands., Population: Two-year nationwide cohort., Methods: Prospective inclusion of Rhc-negative women with negative first trimester screening and of screen-negative controls. Assessment of incidence and numbers needed to screen (NNS) of late alloimmunisation and HDFN; logistic regression analysis to establish risk factors for late alloimmunisation., Main Outcome Measures: Late alloimmunisation, HDFN., Results: Late alloimmunisation occurred in 99 of 62 096 (0.159%) Rhc-negative women; 90% had c/E antibodies and 10% non-Rhesus antibodies. Severe HDFN (fetal/neonatal transfusion) occurred in two of 62 096 (0.003%) of Rhc-negative women and 2% of late alloimmunisations; moderate HDFN (phototherapy) occurred in 20 children [22.5%; 95% confidence interval (CI), 13.8-31.1%]. Perinatal survival was 100%. The NNS to detect one HDFN case was 2823 (31 048 for severe, 3105 for moderate HDFN). Significant risk factors were former blood transfusion [odds ratio (OR), 10.4; 95% CI, 1.14-94.9], parity (P-1: OR, 11.8; 95% CI, 3.00-46.5; P > 1: OR, 7.77; 95% CI, 1.70-35.4) and amniocentesis/chorionic villus sampling during current pregnancy (OR, 9.20; 95% CI, 1.16-72.9)., Conclusions: Additional screening of Rhc-negative women improved the detection of late alloimmunisation and HDFN, facilitating timely treatment, with a NNS of 2823. Independent risk factors for late alloimmunisation were blood transfusion, parity and chorionic villus sampling/amniocentesis in the current pregnancy. The occurrence of most factors before the current pregnancy suggests a secondary immune response explaining most late alloimmunisations., Tweetable Abstract: Third trimester screening for alloimmunisation in Rhc-neg women improves detection and treatment of severe HDFN., (© 2015 Royal College of Obstetricians and Gynaecologists.)

Haemolytic Disease of the Fetus and Newborn (HDFN) is caused by maternal alloimmunization against red blood cell antigens. In severe cases, HDFN may lead to fetal anaemia with a risk for fetal death and to severe forms of neonatal hyperbilirubinaemia with a risk for kernicterus. Most severe cases are caused by anti-D, despite the introduction of antental and postnatal anti-D immunoglobulin prophylaxis. In general, red blood cell antibody screening programmes are aimed to detect maternal alloimmunization early in pregnancy to facilitate the identification of high-risk cases to timely start antenatal and postnatal treatment. In this review, an overview of the clinical relevance of red cell alloantibodies in relation to occurrence of HDFN and recent views on prevention, screening and treatment options of HDFN are provided., (© 2015 International Society of Blood Transfusion.)

Objective: The objective of the study was to determine whether women with combinations of red blood cell antibodies are more likely to develop significant hemolytic disease of the fetus and newborn than those with single antibodies., Study Design: A retrospective exposure cohort study was conducted of pregnant women with red blood cell antibodies. The development of significant hemolytic disease of the fetus and newborn was then compared between patients with single antibodies and those with multiple antibodies. Data analysis was limited to pregnancies delivering since the year 2000., Results: Thirteen percent of the patients referred to our program had multiple red blood cell antibodies. Odds of developing significant hemolytic disease of the fetus and newborn for patients with anti-Rh(D) combined with at least 1 additional red blood cell antibody were 3.65 times the odds for women with anti-Rh(D) antibodies in isolation (95% confidence interval, 1.84-7.33). In the setting of multiple antibodies including anti-Rh(D), Rh-positive fetuses/neonates have an increased odds of developing significant hemolytic disease even if the fetus is negative for the other corresponding red blood cell antigen., Conclusion: Women with multiple red blood cell antibodies are more likely to develop significant hemolytic disease of the fetus and newborn than those with a single antibody especially in the presence of anti-(Rh)D. This pathophysiology may suggest a more aggressive immune response in women who develop more than 1 red blood cell antibody., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Background: The RhD antigen is very immunogenic and is a significant cause of hemolytic disease of the newborn (HDN). The RHD-CE(8-9)-D hybrid allele is commonly associated with a D- phenotype. Here, we report a case of high-titer maternal anti-D and late onset of HDN in a newborn carrying a RHD-CE(9)-D variant supposedly encoding the same partial D antigen as the RHD-CE(8-9)-D allele, but with significant expression of D antigen., Study Design and Methods: To elucidate the blood group antigen background of the case, we carried out serologic, flow cytometric, and genetics studies of the newborn and his father., Conclusion: Individuals carrying the RHD-CE(9)-D allele do express D antigen, but do so at significantly lower levels than those carrying the more common D+ phenotypes (e.g., DCe/dce). It may mitigate and delay otherwise severe HDN in pregnancies complicated by high-titer anti-D., (© 2014 AABB.)

Background: Neonates with Rhesus c (Rh c) hemolytic disease of the fetus and newborn (HDFN) are often managed in the same way as neonates with Rhesus D (Rh D) HDFN, although evidence to support this policy is limited. The objective of this study was to evaluate neonatal outcome in severe Rh c HDFN compared to Rh D HDFN., Study Design and Methods: A retrospective study of (near-)term neonates with severe Rh c (n = 22) and Rh D HDFN (n = 103; without additional antibodies) admitted to the Leiden University Medical Center between January 2000 and October 2011 was conducted. The need for intrauterine transfusions (IUTs), phototherapy, exchange transfusions (ETs), and top-up transfusions up to 3 months of age were recorded and compared between both groups., Results: Although there was a trend for a slightly more severe antenatal course for Rh D HDFN reflected by an earlier need for and higher number of IUTs (median [interquartile range], 2 [1.5-4] vs. 2 [1-2] in Rh c HDFN; p = 0.070), no significant differences were found for the postnatal course between Rh c and Rh D group in days of phototherapy (mean, Days 4.8 and 4.6, respectively; p = 0.569), need for ET (50% vs. 44%, respectively; p = 0.589), and top-up transfusions (62% vs. 78%, respectively; p = 0.128)., Conclusion: Postnatal outcome in neonates with severe Rh c HDFN is similar compared to neonates with severe Rh D hemolytic disease in terms of days of phototherapy, need for ET, and need for top-up transfusions. These results justify a similar postnatal management of neonates with Rh D and Rh c HDFN., (© 2012 American Association of Blood Banks.)

Background: Women whose fetuses were treated with intrauterine transfusions (IUTs) for alloimmune hemolytic disease are high responders to red blood cell (RBC) antigens. We investigated the risk for HLA alloimmunization., Study Design and Methods: Women and their children treated with IUT between 1987 and 2008 were included. Participants were HLA antigen typed and studied for the prevalence of HLA antibodies compared to age-matched parous nontransfused blood donors. Anti-D titer, the formation of new RBC antibodies after IUT, and the degree of fetomaternal HLA mismatches on HLA antibody formation and/or persistence were analyzed., Results: A higher prevalence of HLA Class I antibodies was observed in these women compared to controls (41% vs. 23%). Both a higher anti-D titer (>8000) and formation of new RBC antibodies after IUT were associated with increased HLA immunization. HLA antibody formation was associated with the number of fetomaternal triplet epitope mismatches. Antigens within HLA-Bw4, HLA-B35/51/52/53/18/78-complex and A1/A9, were higher and mismatches within HLA-C were less immunogenic than expected. HLA antibodies against the IUT-treated fetus were more persistent than other antibodies., Conclusion: Women whose fetuses were treated with IUT had a high risk of developing and maintain fetal-specific HLA Class I antibodies. Factors associated with increased HLA immunization were a higher amount of fetomaternal HLA triplet mismatches, higher anti-D titer, and additional RBC antibody formation. We presume that the induction of HLA Class I antibodies is the result of increased fetomaternal hemorrhage during IUT, eliciting antibodies in women with an increased susceptibility to alloimmunization., (© 2012 American Association of Blood Banks.)

Objective: The aim of this study was to evaluate the diagnostic value of RhD fetal genotyping from the plasma of RhD-negative pregnant women., Methods: We analysed the plasma samples of 65 pregnant women. DNA quantification was done using real time quantitative PCR (RQ-PCR) in multiplex targeting multiple RhD exons 5, 7 and 10, with a standardized pool of plasmid calibrators. Results were compared with serological analysis of cord blood after delivery., Results: Fetal RhD status was predicted with 95.38% accuracy from maternal plasma of pregnant women in the 11(th) to 40(th) weeks of gestation. One false positive but no false negative results were found. Thus the sensitivity of the assay was 100% and the specificity was 94.44 %., Conclusion: The present data demonstrates that the fetal RhD genotyping approach could be achieved efficiently with RQ-PCR for RhD-negative tunisian pregnant women.

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.

Aims/objectives: To identify the frequency and nature of maternal red blood cell (RBC) alloimmunisation in Uganda and to determine the prevalence of RhD negativity and the rate of RBC alloimmunisation in Ugandan pregnant women., Background: Haemolytic disease of the foetus and newborn (HDFN) results from maternal alloimmunisation following exposure to allogeneic RBCs during pregnancy or blood transfusion. The prevalence of maternal RBC alloimmunisation in Ugandans is not known., Materials and Methods: Pregnant women at Mbarara Hospital, South Western Uganda, were investigated in a cross-sectional study. Demographics, transfusion and obstetric histories were recorded. Maternal RBC alloimmunisation was demonstrated using immunohaematological techniques., Results: A total of 2001 pregnant women were recruited; 3.6% of them being RhD negative. Forty-five women (2.2%; 95% CI: 1.6-2.9) were found to be alloimmunised to RBC antigens. There were 38 RBC alloantibodies of known specificity including anti-S, 12; anti-M, 11; anti-Le(a) , 6; anti-D, 4 and 1 each of anti-K, anti-Fy(b) , anti-Jk(a) , anti-Lu(a) and anti-Kp(a) . In two women (4.4%), there were antibody combinations (anti-M+S and anti-K+Kp(a) ). Obstetric history, gestational age and previous immunising events were not significantly associated with the rate of alloimmunisation., Conclusions: This study revealed a maternal RBC alloimmunisation rate of 2.2% which was comparable with findings from a Zimbabwean study where the prevalence was 1.7%. Given the 6·0% prevalence of anti-D among RhD-negative women in our study and the high immunogenicity of the D antigen, programmes for preventing anti-D alloimmunisation and HDFN in Uganda should be considered seriously., (© 2011 The Authors. Transfusion Medicine © 2011 British Blood Transfusion Society.)

Background: The objective was to determine clinical consequences of anti-D and non-D antibodies undetected at first-trimester screening for infant or fetus., Study Design and Methods: This retrospective cohort study included all pregnant women with red blood cell (RBC) antibodies who were tested between 1993 and 2008. Data were obtained from the forms for tracking immunization at the transfusion department. Each form was analyzed for three data sets: the order of screening at which the antibodies were detected (initial or repeated screening), the order of pregnancy (first pregnancy or higher), and whether the antibodies caused severe hemolytic disease of fetus and newborn (HDFN)., Results: In D- women, anti-D was detected in 1.3% of cases. The anti-D was undetected in 72 (37%) cases on the first-trimester screening, of which eight cases were complicated by severe HDFN. In this group, three patients were primigravidae. An overall non-D incidence of 0.2% was observed. In 16 cases, non-D were undetected on the first-trimester screening (10 anti-c, two anti-E, two anti-C, one anti-S, and one case of anti-Rh17). Non-D antibodies undetected on initial screening caused 11 cases of severe HDFN (27% of all severe non-D HDFN). Ten of them were in multiparous women. Seven of 11 cases with severe HDFN that were missed were caused by anti-c., Conclusion: The third-trimester screening may detect RBC antibodies that were not present or detected on the first-trimester screening. Such screening may be especially relevant in D+ multiparous women due to the risk of HDFN., (© 2010 American Association of Blood Banks.)

Anti-hr0 antibody is a rare Rh blood-type antibody. Anti-hr0 antibody can cause serious neonatal hemolysis. Herein we report a RhEe(-) gravida with anti-hr0 and anti-e antibodies. Such a blood group has not been reported in China., (© 2011 The Authors. Journal of Obstetrics and Gynaecology Research © 2011 Japan Society of Obstetrics and Gynecology.)

Objective: To evaluate neonatal outcome in Kell haemolytic disease compared to Rh D haemolytic disease., Study Design: Retrospective study of all (near)-term neonates with Kell (n=34) and Rh D haemolytic disease (n=157) admitted to our centre between January 2000 and December 2008. We recorded the need for exchange transfusion and top-up transfusions up to 3 months of age., Results: Neonates in the Kell group required less days of phototherapy than neonates in the Rh D group [2.4 vs. 4.1 days, respectively (P<0.01)]. The percentage of neonates requiring an exchange transfusion was lower in the Kell group than in the Rh D group [6% (2/34) and 62% (98/157), respectively (P<0.01)]. The percentage of neonates in the Kell group and Rh D group requiring a top-up transfusion was 62% (21/34) and 72% (113/157), respectively (P=0.20). The median number of top-up transfusions per neonate in the Kell group and Rh D group was 1 [interquartile range (IQR) 0-2] and 2(IQR 0-2), respectively (P=0.07)., Conclusion: Neonates with Kell haemolytic disease require less phototherapy and less exchange transfusions compared to neonates with Rh D haemolytic disease, but an equal number of top-up transfusions., (© 2010 The Author(s). Vox Sanguinis © 2010 International Society of Blood Transfusion.)

Currently under codevelopment by Symphogen and Swedish Orphan Biovitrum, rozrolimupab is the first in a new class of recombinant polyclonal antibodies, known as symphobodies, produced using a proprietary technology from Symphogen. Rozrolimupab is being investigated for the prevention of hemolytic disease of the fetus and newborn (HDFN) and for the treatment of idiopathic thrombocytopenic purpura (ITP). Rozrolimupab comprises 25 genetically unique IgG1 antibodies, all of which are specific for the rhesus D (RhD) erythrocyte protein. In preclinical studies, rozrolimupab demonstrated binding to erythrocytes that was comparable with that of two plasma-derived anti-D Ig preparations. In a phase I clinical trial in healthy male volunteers, treatment with rozrolimupab was not associated with serious adverse events. In a phase II clinical trial of rozrolimupab in healthy, male, RhD-negative volunteers, rozrolimupab dose-dependently cleared RhD-positive erythrocytes from the circulation. Phase II clinical trials in ITP and HDFN are currently ongoing. Phase III clinical trials are necessary to establish the efficacy and safety profile of rozrolimupab compared with standard plasma-derived anti-D Ig preparations.

Anti-E alloimmunisation is a less common cause of haemolytic disease in the newborn (HDN) and is usually associated with mild to moderate clinical manifestations, that are often less severe than anti-D immunisation. Conventional treatments for HDN are phototherapy and exchange transfusion, the latter still representing a high-risk procedure. Currently, intravenous immunoglobulin has been used as alternative treatment for HDN to reduce the need for exchange transfusion, as well as the length of phototherapy and hospitalisation. We report a case of anti-E HDN treated successfully with intravenous immunoglobulin, as adjuvant treatment to phototherapy.

Haemolytic disease of the fetus and newborn (HDFN) due to red cell alloimmunization was a significant cause of fetal and neonatal morbidity and mortality until the introduction of anti-D immunoglobulin, which has dramatically changed the incidence of the disease. However, it is still a major problem in affected pregnancies. The emphasis of current clinical management has shifted from an invasive approach to non-invasive monitoring of the disease. The key elements of the modern management are determining which fetuses are at risk of HDFN with the use of cell-free fetal DNA in maternal plasma (fetal RHD genotype) and the follow-up of antigen positive fetuses by Doppler ultrasonography to detect anaemia severe enough to need treatment. When anaemia is suspected, an invasive approach is still required in a timely manner for confirmation of the degree of anaemia and to administer blood transfusions. This non-invasive approach prevents unnecessary administration of human-derived blood products, with the consequent ethical and cost implications and most importantly avoids iatrogenic conversion of mild to severe disease by avoiding need for techniques such as amniocentesis. The potential problem of the non-invasive approach is the reduction in the total number of invasive procedures, with the subsequent difficulty of maintaining the skills required to perform them., ((c) 2010 John Wiley & Sons, Ltd.)

The recommended dose of Rh immune globulin for postpartum Rh immunoprophylaxis is based on an estimation of the volume of the fetomaternal hemorrhage, if any, measured as the percent of fetal RBCs in a sample of the D– mother's blood. Laboratory methods for distinguishing fetal from maternal RBCs have been based on their different blood types (D+ versus D–) or predominant hemoglobin content (hemoglobin F versus hemoglobin A). We conducted a review of the medical literature describing laboratory methods for detecting and quantifying fetal RBCs in maternal blood samples. We also used data collected for the College of American Pathologists Fetal RBC Detection Surveys to determine which laboratory methods are used currently in hospitals in the United States. The rosette screen is used widely for identifying D– mothers who may require additional doses of Rh immune globulin for postpartum immunoprophylaxis. As the rosette screen targets the D antigen, it is not suitable for detecting a fetomaternal hemorrhage in D+ mothers or when the D type of the fetus or newborn is D– or unknown. The acid-elution (Kleihauer- Betke) assay is a sensitive laboratory method for quantifying a fetomaternal hemorrhage, but it is tedious, often inaccurate, and difficult to reproduce. Flow cytometry, using anti-D or anti-hemoglobin F reagents, offers a more precise quantification of fetal RBCs in maternal blood. However, flow cytometry services for this function are available in relatively few hospital laboratories in the United States because of logistic and fiscal impediments.

Anti-D is routinely and effectively used to prevent hemolytic disease of the fetus and newborn (HDFN) caused by the antibody response to the D antigen on fetal RBCs. Anti-D is a polyclonal IgG product purified from the plasma of D-alloimmunized individuals. The mechanism of anti-D has not been fully elucidated. Antigenic epitopes are not fully masked by anti-D and are available for immune system recognition. However, a correlation has frequently been observed between anti-D-mediated RBC clearance and prevention of the antibody response, suggesting that anti-D may be able to destroy RBCs without triggering the adaptive immune response. Anti-D-opsonized RBCs may also elicit inhibitory FcgammaRIIB signaling in B cells and prevent B cell activation. The ability of antigen-specific IgG to inhibit antibody responses has also been observed in a variety of animal models immunized with a vast array of different antigens, such as sheep RBCs (SRBC). This effect has been referred to as antibody-mediated immune suppression (AMIS). In animal models, IgG inhibits the antibody response, but the T-cell response and memory may still be intact. IgG does not mask all epitopes, and IgG-mediated RBC clearance or FcgammaRIIB-mediated B-cell inhibition do not appear to mediate the AMIS effect. Instead, IgG appears to selectively disrupt B cell priming, although the exact mechanism remains obscure. While the applicability of animal models of AMIS to understanding the true mechanism of anti-D remains uncertain, the models have nevertheless provided us with insights into the possible IgG effects on the immune response.

RhD antigen is the most immunogenic and clinically significant antigen of red blood cells after ABO system. It has historically been associated with hemolytic disease of the newborn (HDN) which is now routinely prevented by the administration of polyclonal anti-D immunoglobulin. This management of HDN has proven to be one of the most successful cases of prophylactic treatment based on antibody mediated immune suppression (AMIS). Despite the increasing efficiency of treatment, the mechanism of action of anti-D is not completely defined. There is a widespread interest in obtaining a reliable therapeutic monoclonal anti-D, due to difficulty of maintaining a pool of high titer volunteer donors for plasma collection and also increasing demand for antenatal prophylaxis and safety issues with plasma derived products. Candidate monoclonal anti-D preparations should demonstrate appropriate functionality in both in vitro and in vivo assays comparable to polyclonal anti-D immunoglobulin. These criteria are reviewed in addition to the factors regulating development of D specific immune response in D negative individuals and its suppression in HDN prophylaxis.

For 40 years prophylactic anti-D has been given to D-negative women after parturition to prevent haemolytic disease of the fetus and newborn. Monoclonal or recombinant anti-D may provide alternatives to the current plasma-derived polyclonal IgG anti-D, although none of them have yet proved as effective in phase 1 clinical trials. The variation in efficacy of the antibodies may have been influenced by heterogeneity in glycosylation of anti-D produced from different cell lines. Some aspects of the conduct of the human studies, most notably the use of low doses of anti-D and target D positive red cells in vivo, may aid the design of the clinical development of other immunomodulatory drugs in order to minimize adverse effects.

Rhesus immune globulin has decreased the prevalence of rhesus D alloimmunization in pregnancy so that only approximately six cases occur in every 1,000 live births. The rarity of this condition warrants consideration of consultation with or referral to a maternal-fetal medicine specialist with experience in the monitoring and treatment of patients with red cell alloimmunization in pregnancy. Evaluation for the presence of maternal anti-D antibody should be undertaken at the first prenatal visit. First-time sensitized pregnancies are followed with serial maternal titers and, when necessary, serial Doppler assessment of the peak systolic velocity in the middle cerebral artery. In cases of a heterozygous paternal genotype, new DNA techniques now make it possible to diagnose the fetal blood type through free fetal DNA in maternal plasma. When there is a history of an affected fetus or infant, maternal titers are no longer predictive of risk in subsequent pregnancies. Serial peak middle cerebral artery velocities using Doppler ultrasonography can be used in these pregnancies to detect fetal anemia. In some situations, intrauterine transfusion is necessary through ultrasound-directed puncture of the umbilical cord with the direct intravascular injection of red cells. Perinatal survival rates of more than 90% have been reported; hydrops fetalis reduces the chance for a viable outcome by up to 11%. Neonatal and infant outcomes are complicated by the need for repeated transfusions secondary to suppressed erythropoiesis. Long-term studies have revealed normal neurologic outcomes in more than 90% of cases. Future therapy will involve selective modulation of the maternal immune system, making the need for intrauterine transfusions a rarity.

Accurate Rh testing can be difficult if the red cells are heavily coated with IgG anti D antibodies - a phenomenon called blocked D. Repeatedly, Rh D negative blood group report was obtained in a newborn male baby with severe haemolytic disease and features of kernicterus born to a 2nd gravida B Rh D negative mother. On investigation, the baby was grouped as B Rh D negative by direct grouping, but after elution, D antigen was detected and phenotyped as CcDe. Antibody was identified as anti D. All D antigens of the baby were fully saturated with anti D leaving any antigen to bind with antisera. Direct Coombs test was strongly positive even after three exchange transfusions. The baby also had free antibody apart from the red cell bound and the red cell eluate, gave a titre of 512. The mother was grouped as B Rh D negative and phenotyped as ce. She had IgM and IgG class of anti D with titres 32 and 1024 respectively. She also had IgM anti C (only in neat) and IgG anti-A with a titre of 512.

Aim: 1) We have presented our experiment conducted to detect anti-K antibodies from the Kell-system in pregnant women and their connection with potential destruction of foetal red cells, which may result in haemolytic disease of the foetus and the newborn (HDFN). 2) We have also indicated serological and molecular methods important for a proper diagnosis., Material and Methods: 27 women with anti-K. Serological diagnosis of K antigen in fathers and children. KEL1 gene examination in foetuses from DNA isolated from foetal cells contained in amniotic fluid, using discrimination of alleles--real-time PCR method., Results: Anti-K were detected in most women after blood transfusion, the fathers were usually K negative. Foetomaternal incompatibility was found in 6 out of 27 women. Haemolytic disease was observed in 5 cases: 3-severe, 1-fatal, 1-mild. Foetal genotyping allowed us to avoid cordocentesis in two pregnant women, it appeared that both foetuses have not received KEL1 gene from heterozygous (Kk) fathers--in the previous pregnancies the children had died because of HDFN., Conclusions: 1) In every pregnant woman with anti-K, the K antigen should be examined in the father. 2) In every K+ father the phenotype should be evaluated and if he is heterozygote (Kk), the fetal KEL1 gene must be examined, to avoid unnecessary cordocentesis. 3) If KEL1 gene is not detected in the foetus, HDFN will not occur. 4/Foetal KEL1 genotyping may be performed in all mothers with anti-K and heterozygous father in our Department, after providing the material from the amniocethesis.

Background: Hemolytic disease of the fetus and newborn (HDFN) is a severe disease, resulting from maternal red cell (RBC) alloantibodies directed against fetal RBCs. The effect of a first-trimester antibody screening program on the timely detection of HDFN caused by antibodies other than anti-D was evaluated., Study Design and Methods: Nationwide, all women (1,002 in 305,000 consecutive pregnancies during 18 months) with alloantibodies other than anti-D, detected by a first-trimester antibody screen, were included in a prospective index-cohort study. In a parallel-coverage validation study, patients with HDFN caused by antibodies other than anti-D, that were missed by the screening program, were retrospectively identified., Results: The prevalence of positive antibody screens at first-trimester screening was 1,232 in 100,000; the prevalence of alloantibodies other than anti-D was 328 in 100,000, of which 191 of 100,000 implied a risk for occurrence of HDFN because the father carried the antigen. Overall, severe HDFN, requiring intrauterine or postnatal (exchange) transfusions, occurred in 3.7 percent of fetuses at risk: for anti-K in 11.6 percent; anti-c in 8.5 percent; anti-E in 1.1 percent; Rh antibodies other than anti-c, anti-D, or anti-E in 3.8 percent; and for antibodies other than Rh antibodies or anti-K, in none of the fetuses at risk. All affected children, where antibodies were detected, were promptly treated and healthy at the age of 1 year. The coverage validation study showed a sensitivity of the screening program of 75 percent. Five of 8 missed cases were caused by anti-c, with delay-induced permanent damage in at least 1., Conclusion: First-trimester screening enables timely treatment of HDFN caused by antibodies other than anti-D, however, with a sensitivity of only 75 percent. A second screening at Week 30 of c- women will enhance the screening program. Severe HDFN, caused by antibodies other than anti-D, is associated with anti-K, anti-c, and to a lesser extent with other Rh-alloantibodies.

Maternal antibody-mediated fetal red blood cell destruction secondary to non-D Rhesus (Rh) antibodies is a significant cause of hemolytic disease of the newborn (HDN). Here, we report a rare case of severe HDN associated with maternal antibody to Rh e. In addition to severe anemia, the infant developed thrombocytopenia, conjugated hyperbilirubinemia and cholelithiasis. Resolution of the infant's cholelithiasis occurred following treatment with ursodeoxycholic acid.

C(w) is a low-frequency antigen in the Rhesus blood group system. Anti-C(w) can occur naturally or develop as a result of red blood cell sensitization through transfusion or pregnancy. Clinically significant hemolytic disease of the newborn is rarely associated with anti-C(w), with no previous reported cases of hydrops fetalis or severe fetal anemia resulting in intrauterine death. We report an unusually severe case of intrauterine hemolysis resulting from this rare condition. The neonate presented with early-onset hyperbilirubinemia and severe anemia at birth requiring multiple exchange transfusions in the first 24 hours of life. The mother of this infant had a significantly poor obstetric history, having delivered a stillbirth with massive hepatosplenomegaly previously. This case report suggests that intrauterine hemolysis due to anti-C(w) may be life threatening to the unborn fetus.

In India, at the majority of the transfusion centers, antenatal antibody screening is done only in Rh (D) negative mothers. We report here two cases of haemolytic disease of newborn (HDN) by maternal alloimmunization to anti-c in one case, and both anti-c and anti-E in the second case. Both women were Rh (D) positive mothers and HDN was detected postnatally by a positive direct antiglobulin test (DAT) in their newborns. These cases highlight the importance of routine antenatal antibody screening even in Rh (D) positive females. A close follow-up throughout pregnancy is required if irregular antibodies are present so that antigen negative, crossmatch compatible blood can be provided in a timely manner for intra-uterine or exchange transfusions.

Objective: Intrauterine transfusion (IUT) is a life-saving therapy for the severely anemic fetus with hemolytic disease. However, maternal additional antibody formation is a complication of the procedure. In this study, we determined antibody formation after introduction of preventive Rh-D, -C, -c, -E, and -e and K matching of IUT donors., Study Design: This was a retrospective follow-up study., Results: During an 11-year period, 686 Rhesus- and K-matched IUTs were performed in 233 pregnancies and in 95% (652/686) posttransfusion antibody testing was performed after a median interval of 21 days. Twenty-five percent (53/212) of the women formed 64 new antibodies and, compared to our previous study, this incidence was not decreased by the use of Rhesus- and K-matched donors. After delivery, 72% (153/212) of the women had multiple RBC antibodies. Additional antibodies were in 48% (31/64) directed against Rhesus and K antigens, induced by the fetus, or as natural antibodies. In 52% (33/64) the antibodies were directed against non-Rhesus and -K antigens and in 65% (11/17) of eligible cases the IUT donor and not the fetus expressed the corresponding antigen(s)., Conclusion: Despite Rhesus- and K-matching, women treated with IUTs still show strikingly broad red cell alloimmunization. More extensive IUT donor red cell matching, including FY, JK, and S antigens, to reduce the formation of new red cell antibodies should be explored.

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.

The Rh system is one of the most important and complex blood group systems because of the large number of antigens and the serious complications for the fetus of a woman sensitized by transfusion or pregnancy. Major advances in our understanding of the Rh system have occurred with the cloning of the genes and with functional evidence that the Rh blood group proteins belong to an ancient family of membrane proteins involved in ammonia transport. The arrangement and configuration of the genes at the RH locus promotes genetic exchange, generating new antigens. Importantly, RH genetic testing can now be applied to clinical transfusion medicine and prenatal practice. This includes testing for RHD zygosity, confirmation or resolution of D antigen status, and detection of altered RHD and RHCE genes in individuals at risk for producing antibodies to high-incidence Rh antigens, particularly sickle cell disease (SCD) patients. The Rh proteins form a core complex that is critical to the structure of the erythrocyte membrane, and they may play a physiologic role in the sequestration of blood ammonia. The Rh family of proteins now includes non-erythroid homologs present in many other tissues, and comparative genomics reveal Rh homologs in all domains of life.