A challenging case of hemolytic disease of the fetus and newborn (HDFN) due to anti-Ku in a K0 (Kellnull) mother.

Hemolytic disease of the fetus and newborn (HDFN) due to an antibody in the Kell blood group system can be associated with severe fetal anemia. This case report details the challenges of managing a Kellnull mother with anti-Ku that affected her fetus/newborn. A gravida 4 para 3 woman at term underwent an emergency lower caesarean section because of fetal distress. The baby was intubated because of low oxygen saturation. An urgent request for a hematology workup showed severe anemia and erythroblastosis fetalis. Unfortunately, no compatible blood was found, and the baby died. The case was referred to the National Blood Centre, and anti-Ku was confirmed in a sample sent from the mother. When she presented with her fifth pregnancy, meticulous planning was used to manage this pregnancy. Her family screening revealed one brother with a matching phenotype. Three blood donations were planned for the brother-for freezing, for intrauterine transfusion, and for standby during delivery. Serial anti-Ku titrations of maternal samples were performed, and the fetus was monitored for anemia through middle cerebral artery Doppler scans. Although the anti-Ku titers reached as high as 1024, fetal anemia was never diagnosed. The neonate was delivered safely but was diagnosed with severe pathologic jaundice and anemia secondary to HDFN and congenital pneumonia. The baby was transfused with K0 packed red blood cells and later discharged to home.

Study of the D-- phenotype reveals erythrocyte membrane alterations in the absence of RHCE.

Red cells with the D-- phenotype do not express the RHCE protein because of mutations in both alleles of the RHCE gene. At present, little is known of the effect this has on the normal function of erythrocytes. In this study a group of five families belonging to a nomadic tribe in Malaysia were identified as carriers of the D-- haplotype. Analysis of homozygous individuals' genomic DNA showed two separate novel mutations. In four of the families, RHCE exons 1, 9 and 10 were present, while the 5th family possessed RHCE exons 1-3 and 10. Analysis of cDNA revealed hybrid transcripts, suggesting a gene conversion event with RHD, consistent with previously reported D-- mutations. Immunoblotting analysis of D-- erythrocyte membrane proteins found that Rh-associated glycoprotein (RHAG) migrates with altered electrophoretic mobility on sodium dodecyl sulphate polyacrylamide gel electrophoresis, consistent with increased glycosylation. Total amounts of Rh polypeptide in D-- membranes were comparable with controls, indicating that the exalted D antigen displayed by D-- red cells may be associated with altered surface epitope presentation. The adhesion molecules CD44 and CD47 are significantly reduced in D--. Together these results suggest that absence of RHCE polypeptide alters the structure and packing of the band 3/Rh macrocomplex.

Red cell phenotyping of blood from donors at the National blood center of Malaysia.

BACKGROUND: Human blood groups are polymorphic and inherited integral structures of the red cell membrane. More than 300 red cell antigens have been identified and further categorized into 30 major discrete systems. Their distribution varies in different communities and ethnic groups. AIMS: This work was set to determine the prevalence of red cell phenotypes in donors from the major ethnic groups in Malaysia, namely, Malays, Chinese, and Indians. MATERIALS AND METHODS: The work utilized the dextran acrylamide gel technique in which four types of gel cards were used to identify the blood groups of 594 subjects collected at the National Blood Transfusion Centre, Malaysia. RESULTS: Blood group O and CDe/CDe (R1R1) were the most common in all ethnic groups. The cde/cde (rr) was more prevalent amongst Indians. The rare phenotypes found were cDE/cDE(R2R2) and cDE/CDE(R2Rz). With the Lewis system, the distribution of Le(a-b+) was similar among the ethnic groups. The rarest phenotype Fy(a-b-) was discovered in two donors. Jk(a-b-) was found in seven Malays and in two Indians. In the MNSs system, MN was common in Malays and Chinese, while the MM was more common among Indians. The rare SS was found in 19 donors. Malay and Chinese subjects had high P1 Negative blood but Indians showed high P1 positive blood. Within the Kell System, the very rare KK type was found in six subjects. CONCLUSIONS: The results obtained serve as an established database for the distribution of red cell phenotypes based on the blood group systems of donors from the major ethnic groups in Malaysia.