anti-Rh Antibodies Research Articles

Neonatal and Obstetrical Outcomes of Pregnancies Complicated by Alloimmunization.

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. 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. 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. 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.

Effects of prophylactic red blood cell (RBC) transfusion with extended antigen matching on alloimmunization in patients with Sickle Cell Disease (SCD)

BackgroundRBC alloimmunization remains a significant problem for many patients with SCD. To reduce alloimmunization some strategies have been implemented to provide limited or extended antigen matched RBC transfusions to patients with SCD who need chronic transfusion support. The aim of this study was to evaluate the effects of prophylactic RBC transfusion with extended antigen matching on alloimmunization in patients with SCD. MethodsThis is a 20-year retrospective study of patients with SCD transfused with RBCS that were prospectively matched for D, C, c, E, e, K, Fya/Fyb, Jka/Jkb and S antigens. Our study included 95 patients, and none had antibodies documented before their first transfusion. Patients and donors were phenotyped and molecular typing was performed in all patients who had recent transfusions or a positive direct antiglobulin test to predict their antigen profile. Unexpected antibodies to the Rh system, meaning anti-Rh antibodies in patients whose serologic phenotype was Rh positive, were investigated by molecular genotyping for RH variant alleles. ResultsDuring this study-period, 12 (12.6%) were alloimmunized and 83 (87.4%) were not. Among the 12 patients who alloimmunized, 7 (58.3%) developed antibodies to Rh antigens and 5 (41.7%) produced antibodies to low prevalence antigens. All patients who developed Rh antibodies had RH variant alleles. Autoantibodies were found in 16 (16.8%) transfused patients. ConclusionSCD patients benefit from receiving prophylactic RBC transfusions with extended antigen matching, as demonstrated by the reduction on the rates of alloimmunization and the lack of antibodies to K, FY, JK and S antigens, however, this strategy does not avoid alloimmunization to Rh and low-prevalence antigens.

Prevalence and specificity of red blood cell antibodies in patients transfused in tertiary hospitals in Burkina Faso.

Sub-Saharan African countries face the challenge of immunological transfusion safety that puts many patients at risk of post-transfusion hemolytic reactions. This is because pre-transfusion testing for irregular/unexpected antibodies that helps to prevent these risks are neither universally available nor accessible. The aim of our study was to determine the prevalence of red blood cell alloantibodies and their specificity in patients transfused in Burkina Faso. This was a cross-sectional study including patients who had received at least one blood transfusion. Indirect antiglobulin testing using LISS-enhanced medium gel column agglutination technique was used for antibodies screening and identification. Enzymatic technique with papain-treated red cell reagent was performed in attempt to solve some difficulties if necessary as well as auto-control test and RH-KEL phenotyping when possible to help antibodies identification. A total of 832 patients were included, 51.6% of whom were female, and the median (IQR) age was 34 (20-49) years. Of these, 43.7% had chronic kidney disease and 20.4% were sickle cell patients. The median (IQR) number of immunisation episodes (blood transfusion and pregnancies) was 3 (2-6) with the median (IQR) number of blood units received per patient of 2 (1-5). The proportion of patients with RBCs antibodies was 6.4% (53/832), with mainly anti-Rh antibodies. A combination of 2 antibodies was found in 7 patients and a combination of 3 antibodies in one patient. Antibodies of unknown specificity (AUS) were encountered in 29%. Independent factors associated with antibody positivity were age (OR=1.02; p=0.026), sickle cell disease (OR=3.23; p=0.017) and receiving more than 10 blood units (OR=7.33; p=0.01). In this study, the proportion of patients with RBC antibodies was quite similar to that observed in Sub-Saharan African countries. However, the availability and accessibility of pre-transfusion compatibility tests as well as the quality of methods used should be improved to ensure the safety of blood transfusions.

Prophylaxis of rhesus-sensitization of pregnant women. Experience of anti-rhesus immunoglobulin Rhesogam® N using

Aim. Retrospective assessment of the efficiency and safety of the anti-rhesus Rh (D) immunoglobulin Rhesogam N in preventing isoimmunization in Rh-negative women during pregnancy.
 Materials and methods. An analysis of medical records of 196 Rh-negative patients who received anti-Rh immunoglobulin Rhesogam N in the period 20192021 was performed. The indications for the drug were the aspiration of chorionic villi, amniocentesis and prenatal prophylaxis in women with negative level of anti-Rh antibodies and in the case of Rh-positive husbands.
 Results. In total, 227 doses of the anti-rhesus immunoglobulin Rhesogam N were administered, including those women who underwent invasive procedures (aspiration of chorionic villi, amniocentesis). There were no adverse events, including anaphylaxis or drug-related events. 172 rhesus-positive babies were born. No cases of hemolityc disease of the newborns were reported. Anti-Rh antibodies were not found in their mothers after childbirth.
 Conclusion. The study confirmed the efficacy and safety of the antiresus Rh (D) immunoglobulin Rhesogam N for the prevention of Rh isoimmunization.

Detection of Rh Antibodies in Patient Plasma Using Genome Engineered Induced Pluripotent Stem Cell-Derived Red Cells

Background: Despite transfusion of Rh matched red cells for patients with sickle cell disease, Rh alloimmunization remains a persistent challenge. Rh specificities can be complex, resulting from RH genetic diversity found in patients and donors. Antibody identification is hampered by the lack of appropriate reagent red cells, especially those that can identify antibodies against high prevalence or low prevalence Rh antigens. We used human induced pluripotent stem cells (iPSCs) with the goal of producing renewable red cell reagents to both screen for Rh alloimmunization and to aid complex antibody identification.Methods: We generated a panel of iPSCs that include Rh null, D–, lack the high prevalence antigens hr S or hr B, or express uncommon Rh antigens such as V, VS, Go a, or DAK. For the Rh null line, we used CRISPR/Cas9 genetic engineering to disrupt RHCE via a large deletion in a D- iPSC. For D–, RHD was inserted into the AAVS1 safe harbor locus of an Rh null iPSC line using zinc finger nucleases resulting in a line that constitutively expresses RhD but no RhCE. iPSCs with uncommon variants were reprogrammed from RH genotyped donors or engineered similar to the generation of the D– line. Hematopoietic differentiation by embryoid body formation was used to generate hematopoietic progenitors that were subsequently cultured towards the erythroid lineage. Mature iRBCs were ficin treated and tested with patient plasma with previously identified Rh antibodies using gel agglutination assays.Results: Rh null iPSC-derived RBCs (iRBCs) showed complete absence of cell surface Rh protein by flow cytometry, while D– iRBCs showed Rh protein expression levels comparable to D-ce+ iRBCs using an anti-D/CE antibody. We assessed RBC agglutination of Rh null, D–, hr S-, hr B-, VVS+, Go a+, and DAK+ iRBCs using standard Rh typing reagents (Ortho). The reprogrammed uncommon donor iRBCs agglutinated with monoclonal anti-Rh antibodies as predicted by RH genotype, while the Rh null iRBCs showed no agglutination with all 5 common Rh antibodies and D– iRBCs showed agglutination with anti-D reagents only. Rh null iRBCs showed no agglutination against patient plasma containing anti-D, while D– iRBCs agglutinated. While D- RHCE*ce homozygous iRBCs showed strong agglutination against patient plasma containing anti-hr S, Rh null, D–, and hr S- iRBCs did not agglutinate. No iRBCs showed agglutination by plasma containing anti-V/VS while VVS+ iRBCs showed strong agglutination. Similarly, no iRBCs showed agglutination by plasma containing anti-Go a while Go a+ iRBCs showed strong agglutination. Detection of most antibodies against Rhce on iRBCs was enhanced by ficin treatment whereas antibodies with D specificity did not require ficin treated cells for detection.Conclusion: We suggest that genetically engineered iPSCs expressing uncommon Rh antigen phenotypes that are difficult or impossible to obtain from red cell donors can expedite antibody identification. Rh null and D– iRBCs could be useful to discriminate antibodies against RhD versus RhCE. Customized iPSCs that lack high prevalence or express low prevalence Rh antigens could potentially standardize antibody evaluation in patients with complex Rh specificities. DisclosuresNo relevant conflicts of interest to declare.

Prevalence of Unexpected Red Cell Antibodies in Healthy Donor Population in a Tertiary Care Center in South Kerala

Background and Objectives: Apart from naturally occurring red cell antibodies Anti-A and Anti-B in human plasma, there are two types of unexpected red cell antibodies: Alloantibodies and auto-antibodies. The presence of these antibodies, alone or in combination, makes difficulties with compatibility testing, thereby delaying in the issue of a compatible blood unit or may reduce posttransfusion red blood cells life span. Antibody screening is mandatory as laid down by the Drug and Cosmetic Act 1940 and Directorate General of Health Services guidelines. This goal of this paper was to study the prevalence of Unexpected Red Cell Antibodies in Healthy Donor Population in a Tertiary Care Centre in South Kerala. Methods: The sample size chosen for this study was 7000 randomly chosen healthy nonremunerated voluntary donors who attended in house and blood donation camps over a period between November 26, 2017, and February 15, 2019. Results: The prevalence of unexpected red cell antibodies was found to be 1 in 1000. Male blood donations were more than female and blood donors among 18–30 years of age were greater in number. There were no cases of direct antiglobulin test positivity encountered. Male: Female ratio is 2.5:1 and males had naturally occurring alloantibodies, whereas females had a previous history of pregnancy. Anti-M and Anti-Lewis antibodies were the most common alloantibodies followed by Anti-Rh (D and C) antibodies and Anti-IH in the current study. Benign cold agglutinins (BCA) were found predominately in the younger male population with a significant seasonal variation noted in the prevalence of these antibodies. Conclusion: All antibodies identified had the ability to cause immune hemolytic transfusion reactions in the recipients. BCA-positive cases were seen more during the winter season and rainy seasons when compared to hot climatic conditions.

Corticosteroids for management of Rh-isoimmunization, extended study in a tertiary referral centre.

Background: RhD isoimmunization is a life threatening condition for affected fetuses. It is currently treated only by intrauterine transfusion of packed red blood cells. This procedure required special skill and has potential complications.Aim : The aim of the present study was to evaluate the role of corticosteroids in prevention of fetal anemia due to RhD isoimmunization.Material and Methods: The study was conducted on 15 pregnant patients with RH isoimmunization in Shatby Maternity University Hospital, Alexandria, Egypt, during the period from July 30th 2016 to July 30th 2019. Recruited women received 40 mg oral prednisolone starting from 10th week of gestation. Follow up of Anti-Rh antibodies titer and-from 18 weeks gestation- middle cerebral artery peak systolic velocity (MSA-PSV) was done every 2 weeks. Patients were delivered at 34 weeks gestation by elective caesarean section after receiving 4 doses of dexamethasone to enhance fetal lung maturity.Results: 12 patients continued the trial. Significant reduction was achieved in anti-Rh antibodies titer. Reduction in MSA-PSV was achieved and maintained below 1.5 MOM. Gestational age at delivery ranged from30.3-34 weeks (33.18±1.2 weeks). Fetal eight at delivery ranged from 1550-2270 grams (1978.5±232.5 gm). 9 newborns required NICU admission, only 2 newborns underwent exchange transfusion therapy.Conclusion: In Rh iso-immunization, oral prednisolone proved to have a good rule in preventing fetal anemia and introducing its use should be considered. More studies with bigger sample size are needed to confirm its efficacy

RHD and RHCE molecular analysis in weak D blood donors and in patients with Rh antibodies against their own corresponding Rh antigen.

The Rh system is the largest and most polymorphic blood group system. The existence of a large number of RH alleles results in variant phenotypes that often complicate blood donor phenotyping and the distinction between auto- and allo-antibodies in recipients who have anti-Rh antibodies in the presence of their own corresponding Rh antigen. Knowledge of these variants is necessary in order to make blood transfusion safer. Samples from 48 blood donors with serological weak D and from 29 patients who had anti-Rh antibody in the presence of their own corresponding Rh antigen were evaluated molecularly for RHD and RHCE alleles using a blood-multiplex ligation-dependent probe amplification assay and Sanger sequencing. Rh variants were found in 45 of the 48 blood donors: 24/45 (53%) were weak D, 2/45 (4%) partial D and 19/45 (42%) were weak and partial D. The remaining three donors (6%) did not show a mutation in the RHD allele. Among the 29 patients, 13/29 had anti-e, of whom 4/13 had genotypes that predicted a partial e antigen; 11/29 had anti-D, with 6/11 being identified as partial D; 2/29 had anti-c, of whom 1/2 was predicted to express partial c antigen; 4/29 who had anti-E and 4/29 who had anti-C did not show mutations in RHCE*C or RHCE*E. It was possible to find individuals with clinically significant Rh phenotypes due to the weak reactivity of the D antigen, detected through serological tests in blood donors. In patients, when found with the anti-Rh antibody in the presence of the same Rh antigen, it is difficult to distinguish an auto-antibody from an allo-antibody by serological tests; in these cases, molecular methods (genotyping) can help us to determine whether there are changes in the RH alleles and to discover the nature of the antibody (allo or auto).

Infants affected by Rh sensitization: A 2-year Canadian National Surveillance Study.

Rh sensitization occurs when Rh(D)-negative women develop anti-Rh(D) antibodies following exposure through pregnancy or transfusion. Rh disease may cause jaundice, anemia, neurological impairment, and death. It is rare in countries where Rh Immune Globulin (RhIg) is used. Canadian Rh sensitization and disease rates are unknown. This survey-based study was conducted using a Canadian Paediatric Surveillance Program questionnaire sent to Canadian paediatricians and paediatric subspecialists to solicit Rh disease cases from May 2016 to June 2018. Paediatricians reported Rh-positive infants ≤ 60 days of age, born to Rh-negative mothers with RhD sensitization. Sixty-two confirmed cases of infants affected by Rh(D) sensitization were reported across Canada. The median gestational age of neonates was term, age at presentation was 2 hours, and hemoglobin at presentation was 137.5 g/L (33 to 203 g/L). The median peak bilirubin and phototherapy duration were 280 µmol/L (92 to 771 µmol/L), and 124 hours, respectively. Thirty (48%) infants received Intravenous immune globulin (IVIG) (median two doses). Seventeen (27%) received one to three simple transfusions; 10 (16%) required exchange transfusions. Six (10%) infants presented with acute bilirubin encephalopathy, and less than five presented with seizures. Fourteen mothers with affected infants were born outside of Canada. Rh disease continues to exist in Canada. Additional efforts are needed to raise awareness of Rh disease, prevent disease, and minimize sequelae when it does occur. The ongoing global burden of Rh Disease, as well as the possibility of emerging Rh immunoglobulin refusal are among factors that could be taken into consideration in future prevention efforts.

Red blood cell alloimmunization in Iran: A Comprehensive review of the literature.

BACKGROUND:Alloimmunization is an immune response against foreign antigens which introduced into the body through transfusion, pregnancy, or transplantation. This phenomenon is a big challenge in patients, which require regular transfusions. In the current study, we tried to have a comprehensive review on the status of alloimmunization in Iran. For this purpose, we searched for papers investigating alloimmunization in transfusion-dependent patients and also in patients with no regular transfusions who are candidate for surgery or who need blood.METHODS:We searched PubMed, Google Scholar, SID, and MAGIRAN databases using the following keywords: “blood transfusion,” “alloimmunization,” “alloantibodies,” “irregular antibodies,” “red cell antibodies,” and “Iran.” No limitation for the date of publication and language of the papers was defined. All the identified records were then screened for the relevance and duplication.RESULTS:A total of 22 papers were included in this study. All of the studies were conducted from 1999 to 2016 and providing alloimmunization data from different cities all over of Iran. In general, the results showed that the most prevalent alloantibodies are anti-Kell (anti-K antigen) and anti-Rh system, mainly anti-E, anti-D, anti-C, and anti-c.CONCLUSION:Anti-Kell and anti-Rh antibodies are the most prevalent antibodies responsible for alloimmunization in Iranian population.

Case series of severe fetal hemolysis in Rh-C-negative mother

Anti-Rh(c) antibody is the third most common cause of severe hemolytic disease of the fetus and newborn (HDFN). The widespread use of anti-D immunoglobulin has led to arelative increase in the importance of non-RhD isoimmunization as a cause of HDFN. The Rhc is a part of the Rh blood group system and its prevalence in India is 52%–62%. Here, we report two cases with anti-c antibody with severe hyperbilirubinemia who required intravenous immunoglobulin, red blood cells transfusion, and phototherapy.

Study of Frequency and Characteristics of Red Blood Cell Alloimmunization in Thalassemic Patients: Multicenter Study from Palestine.

Background. β-Thalassemia is a common inherited hemolytic disorder in Palestine. Red blood cell (RBC) transfusion is the principal treatment but it may cause RBC alloimmunization. This study was conducted to determine the prevalence and characteristics of RBC alloimmunization among thalassemic patients in northern governorates of Palestine. Methods. A prospective multicenter observational study was conducted in the thalassemia transfusion centers in the northern governorates of Palestine. The study included 215 thalassemia patients who received regular blood transfusions. Clinical and transfusion records of patients were examined. Antibody screening and identification was conducted using the microcolum gel technique. Results. Two hundred fifteen patients were included in the study. More than half (52.1%) of the patients were males. The median age of patients was 18 years (range: 12–24 years). The most frequent blood group was A (40.5%). Alloantibodies were detected in 12.6% of patients. Anti-D (33.3%), anti-K (25.9%) and anti-E (14.8%) were the most commonly isolated antibodies. There was no association between age, sex, starting age of transfusion, number of transfused units, history of splenectomy and alloimmunization. Conclusions. Anti-Rh and anti-K antibodies were common among this cohort of patients. Age, sex, starting age of transfusion, number of transfused units, and history of splenectomy could not predict the occurrence of alloimmunization.

IgG Alloantibodies Against RBC Induced By Pregnancy or Transfusion Have Unique Glycosylation Patterns Which Correlate with Clinical Outcome of Hemolytic Disease of the Fetus or Newborn

Hemolytic disease of the fetus or newborn (HDFN) is a potentially life-threatening disease in which red blood cells (RBC) of the child are destroyed by maternal IgG alloantibodies. HDFN caused by anti-D antibodies is well known, but may also occur due to other RBC antibody specificities, with anti-K, anti-c and anti-E being most frequently implicated (Koelewijn et al. Transfusion 2008;48(5):941-52). Besides alloantibody-mediated RBC destruction, anti-K also impairs erythropoiesis. The composition of the sugar moiety of the IgG-Fc tail influences the binding affinity to IgG Fc receptors (FcγR) on effector cells. Particularly, the absence of core fucose increases the binding of IgG to FcγRIIIa and FcγRIIIb. In previous studies we observed a correlation between fucosylation of anti-D and anti-platelet antibodies with severity of disease in patients with HDFN (n=8) or fetal or neonatal alloimmune thrombocytopenia (FNAIT) (n=48) (Kapur et al Br.J.Haematol. 2014 166 (6): 936-945; Kapur et al Blood 2014;123(4):471-80). The aim of this study was to investigate whether skewed antibody glycosylation also applies to other anti-RBC antibodies and if this is related to the immunization route and disease severity. Clinical data were collected for 146 women with anti-K, c or E antibodies. Anti-K (n=30), anti-c (n=69) and anti-E (n=47) antibodies were purified from serum by acid elution after incubation of the serum with matching positive RBC using antigen-negative RBC as negative-control for specificity of the procedure. Anti-RBC specific IgG antibodies and total IgG antibodies were subjected to tryptic digestion and resulting IgG1 Fc-derived glycopeptides analyzed by MALDI-TOF-Mass Spectrometry. Lowered fucosylation was observed for anti-K IgG (average 75.7% compared to 92.1% of total IgG, p<0.0001), but less than observed for anti-D IgG1 (52.29%, p=0.0008). Also fucosylation of anti-E IgG was lowered (91.1%, p=0.02), but significantly less pronounced then anti-K and anti-D. Surprisingly, anti-c fucosylation was not significantly skewed (89.9%, p=0.25), but with lowered fucose down to 60% in a few anti-c cases. Anti-E is in most cases naturally occurring, which was definitively proven in 17 cases without history of transfusion or E-positive pregnancy. Anti-K is in most cases induced by transfusion (Koelewijn et al BJOG 2009;116 (10): 1307-1314). Analyzing only cases of mothers with blood transfusion history and antigen negative fathers (n=15) also showed lowered fucosylation (p=0.014), suggesting that signatures of low IgG-fucosylation are not related to pregnancy responses. In 113 antigen-positive newborns at risk for HDFN (K: n=16, c: n=62, E: n=35), the glycosylation pattern of the specific IgG correlated with anaemia and severity of jaundice. For anti-K, galactosylation and sialylation correlated with hemoglobin (r=-0.78 ,p=0.0015, and r=-0.59, p=0.0303, resp.). Similar correlations were found with hematocrit levels. A low anti-c fucosylation correlated with increased bilirubin level (r=-0.38, p=0.0186) and severity of jaundice (r=-0.35, p=0.0103). Newborns exposed to anti-c that required a blood transfusion showed significantly lower galactosylation and higher bisection (p=0.03, p=0.01 resp.). In conclusion, we found similar skewing of antigen-specific IgG1 glycosylation for anti-E and anti-K as observed for anti-D and anti-platelet antibodies, although less pronounced. This skewing was not related to the immune response being induced in pregnancy, as similar features were also observed after transfusion. Interestingly, natural anti-E antibodies, probably evoked against non-blood borne antigens and recognizing E by molecular mimicry are far less skewed, possibly explaining why the presence of this antibody rarely has clinical consequences. The less pronounced skewing of glycosylation of anti-c might also explain the lower risk of severe HDFN mediated compared to anti-D. Anti-K glycosylation influenced clinical outcome, but in contrast to anti-Rh antibodies, it was not fucosylation but galactosylation and sialylation that correlated with anaemia. This might be related to the differences in the mechanism by which these antibodies induce anemia. Importantly, the clinical outcome of HDFN is strongly affected by IgG1-glycosylation, which is proving to become an important biomarker in screening for severe cases of HDFN. Disclosures No relevant conflicts of interest to declare.

Hemolytic disease of the fetus and newborn due to multiple maternal antibodies

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. 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. 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. 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.

Legal Briefs: Anemia From Rh Hemolytic Disease of the Fetus and Newborn

A 3,480-g male infant was born at 36 weeks' gestation to a 32-year-old gravida 1 para 1 woman whose pregnancy was complicated by a group B Streptococcus –positive cervical culture result and hemolytic disease of the fetus and newborn (HDFN) due to Rh incompatibility. The prior pregnancy resulted in an infant who was healthy but whose records were unavailable during litigation. On an early prenatal visit for the current pregnancy, the mother's antibody screen result was positive with a titer of 1:8, at which point the obstetrician gave her an injection of anti-Rh antibodies (Rho[D] immune globulin, sold under the brand name RhoGAM). The pregnancy was not monitored for HDFN; the antibody titers were not drawn again until the day of delivery. The plaintiff obstetrician was critical of the treating obstetrician for administering RhoGAM because the patient was already sensitized, for not following the antibody titers, and for not performing aggressive fetal surveillance required in an Rh sensitized pregnancy. He pointed out that the antibody titers of 1:32 or less require serial antibody titers every 2 to 4 weeks. When and if the titers become 64 or greater, then titers and serial amniocentesis become necessary. Because the mother experienced decreased fetal movement for 1 day, her obstetrician admitted her for an evaluation. The plaintiff experts pointed out that decreased fetal movement underscored the anemia, indicating the fetus' attempt to conserve energy. The biophysical profile was found to be 2/10, the only normal score being normal amniotic fluid volume. Of note was an increase in liver size and mild ascites on the fetal ultrasonogram. Pericardial and pleural effusions were not present. The plaintiff experts pointed out that abdominal fluid collections precede pleural and pericardial effusions in hydrops from HDFN. The antibody titer was 1:2,048. The plaintiff obstetrician pointed out that this …

ОПТИМІЗАЦІЯ МЕТОДІВ ПРЕНАТАЛЬНОЇ ДІАГНОСТИКИ РЕЗУС-КОНФЛІКТУ.

Вивчення нових підходів до ведення<br />вагітності у жінок з імунними конфліктами залишаються актуальною проблемою. Найбільші труднощі викликає пренатальна<br />діагностика гемолітичної'хвороби. Вона передбачає як встановлення факту та рівня сенсибілізації'еритроцитарними антигенами,<br />так і визначення ступеня ураження внутріутробного плоду антитілами матері. Високий титр антитіл свідчить лише про<br />вірогідність пошкодження плоду і розвитку гемолітичноїхвороби новонародженого. Серед 120 вагітних з ізосенсибілізацією<br />для встановлення резус-фактора плоду, пренатальна діагностика була проведена у 31 жінки в терміни від 16 до 37 тижнів<br />вагітності. Першим 5 вагітним з резус-від'ємним типом крові резус-фактор плоду визначався при проведенні<br />трансабдомінального амніоцентезу з метою каріотипування плоду. Наступних 26 амнтоцентезів було проведено у вагітних з<br />резус-сенсибілізацією, у яких неодноразово визначалися в крові антирезусні антитіла в титрі від 1:2 до 1:512, але заданими<br />ультразвукової діагностики без ознак резус конфлікту.У 21 обстежених вагітних встановлено, що плід був резус-позитивний,<br />а у 5 (23,8%) вагітних із сенсибілізацією та високими титрами антитіл від 1:64 до 1:512 - був встановлений резус-від'ємний<br />тип крові у плода. Це дало можливість запобігти у них достроковому родорозрішенню та скоротити час перебування у стаціонарі.<br />Вагітні з ізосенсибілізацією за резус-фактором, у яких плід був резус-позитивний, продовжили перебування в стаціонарі під<br />ретельним спостереженням акушер-гінекологів, в динаміці проводилося визначення титру антирезусних антитіл в крові,<br />проведення ультразвукового дослідження. Отримані результати були верифікованні після народження дітей.

RBC alloimmunization and double alloantibodies in thalassemic patients

PurposeAlloimmunization is a common consequence of chronic blood transfusion. Double alloantibody production may complicate the condition of such patients especially for finding matched blood. In this study, we evaluated the frequency of alloantibodies in thalassemic patients with previous history of transfusion reactions.Samples and methodsThis study was performed on 441 multiply transfused thalassemia patients Antibody screening test was carried out using three cell-panel by gel method. Positive patients were followed up for antibody identification using 11-cell panel. Direct combs’ test was performed to detect auto antibodies.ResultsIn a total of 441 cases (362 thalassemia major and 79 intermedia), 234 were males (53.1%) and 207 females (46.9%); mean age 22 years, range 3-61 years. Alloimmunization was detected in 50(11.3%) patients, including 37(74%) patients with one alloantibody, 8(16%) with two antibodies, 4(8%) patients with unknown antibodies and one patient (2%) with autoantibody. The most common alloantibodies were anti-Rh antibodies (-E/e/C/c/Cw) (26%), anti-K (28%), anti-D (16%), and anti-Colton (4%). Double antibodies were detected in eight out of 50 patients, including: Anti-D+anti-C (8%), anti-D+anti-E (2%), anti-Kell+anti-D (2%), and anti-Kell+KPa (2%). A significant association was observed between the transfusion reaction history and the alloantibody detection results (p < 0.05).ConclusionAntibody production against RBC antigens makes hard condition in regular blood transfusion. Double antibodies production may more complicate this situation. Thus, it is advisable to phenotype patients and matches the red cells in multiply transfused thalassemia patients.

Emergency uncrossmatched transfusion effect on blood type alloantibodies

Trauma patients receive emergency transfusions of unmatched Type O Rh-negative (Rh-) blood until matched blood is available. We hypothesized that patients given uncrossmatched blood may develop alloantibodies, placing them at risk for hemolytic transfusion reactions (HTRs). Data regarding alloantibody profiles and HTR occurrence were collected from the records of trauma patients at our university-based trauma center who received emergency uncrossmatched blood from July 2008 to August 2010. A total of 132 patients received 1,570 units of packed red blood cells. Mean injury severity score was 28 ± 1.3. Forty-five (34%) patients died: 27 on hospital day 1; the remaining 18 had no evidence of HTR before death. Four Rh- female patients received Rh+ fresh frozen plasma, but none received Rh+ packed red blood cells. Three Rh- male patients received both Rh+ packed red blood cells and fresh frozen plasma, and one received Rh+ fresh frozen plasma. One patient developed anti-Rh D antibodies. None experienced HTR. One female patient had HTR from reactivation of anamnestic JK antibodies. Thirteen (33%) of 39 patients met criteria for HTR based on urinalysis and 29 (40%) of 72 patients tested met criteria for HTR based on hemoglobin and bilirubin values. Only one patient had confirmed HTR. High rates of injury recidivism in trauma patients increase the likelihood of multiple blood transfusions during their lifetime. Rh- patients who receive Rh+ blood are at risk of developing anti-Rh antibodies, putting them at risk for HTR. The conservation of Rh- blood for use in female patients may be detrimental to Rh- male patients. Laboratory diagnostic criteria for HTR are nonspecific in the trauma population and should be used with caution.

Red blood cell antibody screening in pregnancy

Sir, Hemolytic disease of newborn (HDN) is defined as neonatal anemia and hyperbilirubinemia caused by an incompatibility between maternal and fetal red blood cells (RBCs).[1] In 98% cases it is caused due to ABO and Rh incompatibility and antibodies to other blood group antigens (Kell, c, E, C, Kidd, Duffy, M, and so on) are causative in remaining 2%.[2] More than 43 different RBC antigens have been reported to be associated with HDN.[3] Red cell antibody screening (RCAS) is a valuable tool in the detection of alloantibodies to other blood group systems (other than ABO and Rh) in the serum of patients during pregnancy or prior to transfusion. Red cell antibody identification (RCAI) should then be carried out on a larger panel of RBCs to precisely identify the antibody. In a prospective study carried out on 624 antenatal cases, RCAS was done using a 3-cell panel from Diamed, Switzerland. RCAI was carried out on cases that were positive for RCAS. RCAS was positive in 9 out of 624 cases—1.4% (excluding the 3 cases who had autoantibodies). After RCAI these were identified as anti-D antibody (6 cases, 66%), anti-D with anti-C antibody (2 cases, 22%), and anti-M antibody (1 case, 11%). The most common antibody identified remained anti-D. In 2 cases of Rh negative pregnancy, the RCAS was suggestive of anti-D. RCAI done, however, showed a combination of anti-D and anti-C. One case of anti-M was detected in a G2P1L1D1 lady. The first pregnancy was full-term normal delivery at home, however, the baby died after birth. The mother’s and baby’s blood group was O positive. RCAS done during second pregnancy was suggestive of anti-Duffy (Fya) or anti-M antibody. RCAI done showed anti-M antibody with dosage effect. The second pregnancy was postdated with Intrauterine growth retardation (IUGR,) and Lower segment caesarean section(LSCS) was done for fetal distress. The baby had hyperbilirubinemia and was Direct Coombs test (DCT) positive requiring phototherapy. Rh incompatibility continues to be a common cause for HDN. Patients with no prior history of sensitization can also develop anti-D as seen in 3 of our cases probably due to naturally occurring anti-Rh antibodies or antepartum hemorrhage. Despite the use anti-D immunization, 1%–2% of the cases are still sensitized. Anti-D immunization resulted in a favorable fetal outcome in the study. Anti-D complicated with anti-C presents with more severe HDN as seen in 1 patient who had a previous stillbirth and a hydrops baby despite receiving anti-D. Anti-C antibodies resulting in HDN requiring exchange transfusion have been reported.[4] Anti-M as a cause of HDN is rare as they are usually complete cold antibodies (IgM). However, it can be IgG type resulting in HDN.[3] HDN due to anti-M antibody can be mild to severe with stillbirth and cases requiring exchange transfusion have been reported.[5] Anti-M causing blood group discrepancy and crossmatch incompatibility has been reported in the Indian literature.[6] Antenatal detection of the non-anti-D causes of HDN requires RCAS. If RCAS is positive, the following steps are to be taken. RCAI should be done to identify the antibody. The spouse has to be screened for the presence of offending antigen and the pediatrician has to be alerted about delivery of a potentially sensitized infant. The blood bank should find a suitable antigen-negative donor for transfusion to baby and mother.

Resultados perinatales en gestaciones isoinmunizadas por el anticuerpo anti-rh(d), sometidas a transfusión fetal intrauterina en Rio de Janeiro, Brasil. Una serie de casos entre 1996 y 2006

Objetivo: evaluar los resultados perinatales de las pacientes isoinmunizadas sometidas a transfusión fetal intrauterina en el Instituto Fernandes Figueira (Río de Janeiro, Brasil).Materiales y métodos: estudio descriptivo retrospectivo, que incluyó a mujeres que requirieron transfusión fetal intrauterina entre 1996 y 2006. Se analizaron la historia perinatal, los datos de la asistencia prenatal durante la gestación actual y los resultados perinatales.Resultados: a un total de 85 madres isoinmunizadas, 90 gestaciones y 94 fetos (4 gestaciones gemelares) se les hicieron 316 transfusiones intrauterinas. Todas las 90 gestaciones exhibían anticuerpos anti-Rh(D). Doce fetos (12,8%) demostraban hidropesía en la primera transfusión y cinco (5,3%) tenían ascitis. Ocurrieron diez óbitos perinatales (4 óbitos fetales y 6 óbitos neonatales), totalizando una sobrevida de 89,4%. Fetos sin hidropesía tuvieron una sobrevida de 92,2% y fetos que presentaron hidropesía tuvieron un peor pronóstico, con sobrevida de 76,5%.Conclusiones: los resultados descritos confirman la eficacia y seguridad de la transfusión fetal intrauterina para el tratamiento de la anemia hemolítica inmune, realizada en centros de referencia para enfermedades perinatales.