The Outcome of Hemolytic Disease of the Fetus and Newborn Caused by Anti-Rh17 Antibody: Analysis of Three Cases and Review of the Literature.

BACKGROUND: Anti-Rh17 is a rare red blood cell (RBC) antibody to high-frequency antigens that may cause severe hemolytic disease of the fetus and newborn (HDFN). Despite the rarity of HDFN caused by Anti-Rh17, this antibody was reported in many different populations. Emergency transfusions, especially exchange transfusions, present a huge problem if no compatible RBCs of phenotype D- are available. METHODS: Here we report obstetrical histories of three women and describe their pregnancies complicated by anti-Rh17 antibodies. We summarized published cases of pregnancies complicated by anti-Rh17 and reviewed transfusion treatment and outcomes. Additionally, a simplified flowchart for the management of such pregnancies is proposed. RESULTS: Four pregnancies were affected by severe HDFN, and three of them ended with perinatal death. In the fourth case, the baby was born hydropic and icteric and the condition was rapidly deteriorating. Emergency exchange transfusion was performed with incompatible O-negative RBC units in AB-negative plasma. The baby was discharged on the 14th day in good health. In the available literature, 15 women and 22 pregnancies were reported, 20 of them developed severe HDFN. According to the data, intrauterine transfusion for treatment of HDFN was the most common form of treatment with the donation of the mother's blood. Different options for exchange transfusion were described, including incompatible RBCs. CONCLUSION: In more than 90% of described pregnancies of HDFN caused by anti-Rh17 antibody, transfusion treatment was required. Therefore, RBC from D- phenotype has to be available. According to published data, in emergent circumstances when maternal and blood from donor with phenotype D- is not available, incompatible exchange transfusion is a better choice than delaying transfusion when it is necessary. It is of essential importance that pregnancies with high risk of HDFN due to anti-Rh17 are managed by a multidisciplinary team (transfusion medicine specialist, obstetrician, neonatologist) in a highly specialized tertiary institution.

Anti-D reagents should be chosen accordingly to the prevalence of D variants in the obstetric population.

BACKGROUND: Resolving ambiguous results of D antigen typing is crucial for appropriate and rational administration of anti-D immunoprophylaxis and transfusion practice in obstetric population. The aim of the study was to establish selection criteria of anti-D reagents for our population. METHODS: A total of 12 689 samples from primiparous women in Split-Dalmatia County, Croatia, were typed for RhD antigen during the period of 5 years. Ambiguous results were submitted to additional serologic investigation and genotyping. RHD genotyping was performed by commercial genotyping kits (Ready Gene weak D ® and Ready gene CDE, Inno-Train, Kronberg, Germany). Relative frequencies and accompanying 95% confidence intervals were used to estimate the prevalence of variants. RESULTS: The prevalence of D variants was 0.42% (95% CI 0.31; 0.53). The most common partial D variant was D Va (RHD*05.05), with the prevalence of 0.08% (95% CI 0.03; 0.13). All weak D variants were weak D types 1, 2 and 3 (RHD*weak D type 1, RHD*weak D type 2, RHD*weak D type 3). Weak D samples were distinguishable from partial D in routine typing due to the difference in reactivity of partial D samples with clones D7B8 and RUM-1. Cell line RUM-1 gives weak or negative reactions with partial DVa category. CONCLUSION: The most common partial D variant in our population is DVa. It is recommended to use cell lines which do not strongly agglutinate DVa variant in routine RhD typing. The appropriate choice of reagents will enable the serology methods to recognize the cases in which RHD genotyping is required.

Anti-D Antibodies in Pregnant D Variant Antigen Carriers Initially Typed as RhD.

BACKGROUND: To evaluate the incidence, the consequences, and the prevention strategy of anti-D alloimmunizations of D variant carriers in the obstetric population of Split-Dalmatia County, Croatia. METHODS: RhD immunization events were evaluated retrospectively for the period between 1993 and 2012. Women were tested for RhD antigen and irregular antibodies. Those with anti-D antibody who were not serologically D- were genotyped for RHD. They were evaluated for their obstetric and transfusion history and their titer of anti-D. The neonates were evaluated for RhD status, direct antiglobulin test (DAT), hemoglobin and bilirubin levels, transfusion therapy as well as phototherapy and outcome. RESULTS: Out of 104,884 live births 102,982 women were tested for RhD antigen. Anti-D immunization occurred in 184 women which accounts for 0.9% of individuals at risk of anti-D formation. 181 cases occurred in women serologically typed as D-. Three women were partial D carriers (DVa n = 2, DNB n = 1), initially typed RhD+, and recognized as D variant carriers after the immunization occurred. Anti-D titer varied from 1:1 to 1:16. Six children were RhD+, four had positive DAT, and two underwent phototherapy. CONCLUSION: Anti-D immunization occurred in pregnant partial D carriers (DVa, DNB). RhD+ children had serologic markers of hemolytic disease of the fetus and newborn (HDFN), with no cases of severe HDFN.

The importance of antenatal prevention of RhD immunisation in the first pregnancy.

BACKGROUND: The aim of this study was to examine which pregnancies are associated with RhD immunisation and haemolytic disease of foetus and newborn (HDFN) when postnatal RhD prophylaxis is applied. MATERIAL AND METHODS: This retrospective cohort study included pregnancies with RhD immunisation; each of the pregnant women received anti-D immunoglobulin after delivery, miscarriage or invasive antenatal diagnostic procedures. For each pregnancy we analysed the order of pregnancy that caused immunisation as well as the order of the monitored pregnancy and whether the anti-D antibodies caused HDFN. RESULTS: Anti-D antibody was detected in 1.2% of RhD-negative pregnancies. Out of 89 monitored pregnancies, 56 (63%) were immunised by the first pregnancy, 21 (24%) by the second one, and 12 (13%) by subsequent pregnancies. HDFN occurred in 28 cases; 25 of them were the consequence of the immunisation in the first pregnancy. The most severe cases of HDFN, perinatal death (n=2) and intrauterine transfusion (n=7) were consequence of immunisation during the first pregnancy. Significantly more cases of HDFN were caused by immunisation in the first pregnancy than by immunisation in subsequent pregnancies (χ(2)=12, p<0.01). CONCLUSION: RhD immunisation could be reduced in more than half cases by administering anti-D immunoglobulin at the beginning of the third trimester of pregnancy, especially the first pregnancy.

Characteristics and frequency of DEL phenotype detected by indirect antiglobulin test in Dalmatia county of Croatia.

D variants, collectively called DEL, express trace amounts of D antigen which is considered to be serologically detectable only by adsorption-elution techniques. We detected six cases of DEL phenotype by indirect antiglobulin test, in Dalmatia County of Croatia by routine serological testing of D antigen of new blood donors. RH genotyping found that all six donors carry allele RHD(M295I), RH genotype CcDdee. D antigen densities of D variants were very low, between 26 and 44 D antigens per red blood cell. The frequency of D variants detected by IAT allele RHD(M295I) was 1:272 in D negative donors. Obviously, DEL phenotype is more common in some parts of European population than initially thought. In conclusion, our routine serological testing of D antigen can detect extremely weak D antigen, even RBCs with DEL phenotype and antigen density as low as 26 D antigens per RBC.

Immune thrombocytopenia: serum cytokine levels in children and adults.

BACKGROUND: Immune thrombocytopenia (ITP) is an immune-mediated platelet disorder in which autoantibody-coated platelets are removed from the blood by monocytic phagocytes and there is impaired platelet production. There is a delicate balance of specific cytokine levels, which has an important role in the immune system and is known to be deregulated in autoimmune diseases. This study was designed to investigate the differences in Th cytokine levels between children and adults with newly diagnosed ITP and to compare these profiles to those found in healthy, age-matched controls. MATERIAL/METHODS: The concentration of IL-1alpha, IL-2, IL-3, IL-4, IL-6, IL-10, TNF-alpha, IFN-alpha, and IFN-alpha in serum specimens was analyzed by enzyme-linked immunosorbent assay. RESULTS: At the time of ITP diagnosis, children showed significantly lower serum levels of interleukin IL-2 and tumor necrosis factor TNF-alpha and higher serum level of IL-3 than healthy controls. Serum level of IL-4 in adult ITP patients was higher than those in control subjects. When compared with adults, children with ITP had lower serum level of IL-4, IL-6 and IFN-alpha, and higher level of IFN-alpha. CONCLUSIONS: Significant differences in serum cytokine levels between pediatric patients and healthy controls indicate that cytokine disturbances--especially changes in IL-2, IL-3 and TNF-alpha--might be involved in the pathogenesis of newly diagnosed ITP. TNF-alpha is the most informative variable for discrimination between healthy children and those with ITP.

Relationship between previous maternal transfusions and haemolytic disease of the foetus and newborn mediated by non-RhD antibodies.

BACKGROUND: The aim of this study was to determine the relationship between non-RhD immunisation and the consequent development of haemolytic disease of the newborn in pregnant women with a history of red blood cell transfusion compared to those without a history of transfusion. MATERIALS AND METHODS: This retrospective cohort study included all pregnancies with red blood cell antibodies that were tested between 1993 and 2010. Data were obtained from the forms for immunisation tracking at the Department of Transfusion Medicine. Each form contained data on previous maternal transfusions, antibody specificities and whether the antibodies caused haemolytic disease of the newborn. RESULTS: Clinically significant non-RhD antibodies was found in 214 of 108,000 pregnancies, of which the most frequent were anti-E (n =55), anti-K (n =54), and anti-c (n =52) antibodies. A history of red blood cell transfusion was identified in 102 (48%) of the pregnancies in which non-RhD antibodies were found (in 78% of the anti-K cases, 40% of the anti-c and 18% of the anti-E cases). Non-RhD antibodies caused haemolytic disease of the newborn in 44 cases of which 14 were very severe (2 anti-K, 8 anti-c, 3 anti-Rh17, 1 anti-E). The mother had a positive history of red blood cell transfusion in 39% of the cases of haemolytic disease of the newborn. Anti-c antibodies were involved in all cases with severe haemolytic disease of the newborn and a history of maternal red blood cell transfusion. CONCLUSION: Primary prevention by using K-negative, Rhc-, RhE-, and RhC-compatible red blood cell transfusion for women younger than 45 years may prevent up to 40% of cases of haemolytic disease of the newborn. Rhc compatibile transfusion is the most important prevention strategy against severe haemolytic disease of the newborn caused by non-RhD antibodies.

Severe hemolytic disease of fetus and newborn caused by red blood cell antibodies undetected at first-trimester screening (CME).

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.