Bachsejersen7725

The D antigen is highly immunogenic and may cause alloimmunization to occur after blood transfusion or pregnancy. Some RHD variant alleles express a D antigen that is missing one or more epitopes, thus putting a presumed D+ patient at risk for alloanti-D and hemolytic disease of the fetus and newborn. It is generally accepted that individuals who have a serologic weak D phenotype due to one of three alleles common in Caucasians, RHD*weak D types 1, 2, or 3, are not at risk for alloimmunization. In this study, blood samples from 46 obstetrics patients from a local health system were identified based on discrepant results between automated gel and manual tube testing (n = 20) or based on presentation with a serologic weak D phenotype (n = 26). RHD genotyping was performed using commercial and laboratory-developed tests. Of the 26 serologic weak D samples, 18 (69.2%) were found to carry alleles RHD*weak D type 1, 2, or 3. The remaining eight samples (30.8%) were found to carry partial D alleles. Of the 20 sampdemonstrates that individuals with partial RHD alleles can present with serologic weak D phenotype, such that, without RHD genotyping, these individuals may not be identified as candidates for Rh immune globulin. see more The study also demonstrates that use of two methods (automated gel and tube testing) allows for identification of partial D cases that would otherwise be missed. I.

Blood transfusion, the main therapy for patients with severe thalassemia, is challenged by alloantibodies that can lead to hemolytic transfusion reactions. The use of prophylactic antigen-matched units is recommended, but serologic typing, before the first transfusion, is rarely performed and is not reliable after chronic transfusion. Patient DNA-based typing is a promising strategy, but clinical outcome data are lacking. The aim of this study was to determine the benefits of antigenmatched transfusion guided by DNA-based typing in terms of new alloantibody formation and increases in mean pretransfusion hemoglobin (Hb) levels. We performed DNA-based typing on samples from 24 transfusion-dependent patients with thalassemia who had no serologic phenotyping performed before the first transfusion. These patients were then transfused with antigen-matched donor RBC units that were typed serologically. New alloantibody formation and mean pre-transfusion Hb levels were evaluated after implementing this extended comprotocol. Seventy-four transfusion episodes in six patients were crossmatch-positive due to autoantibodies (patients 2, 4, 8, 9, and 14) or anti-Chido (patient 18) that had been identified before the study. There were no hemolytic transfusion reactions in this study. Five patients (patients 1, 2, 12, 15, and 20) showed increased mean pre-transfusion Hb levels (≥1 g/dL) and one patient (patient 16) had longer intervals between transfusions (compared with those before the protocol), suggesting longer RBC survival, although there was no statistical difference in the whole group. Our study highlights the benefits of DNA-based typing in chronically transfused patients with thalassemia who had no phenotyping data before the first transfusion. Patient DNA-based typing for antigen-matched transfusion is safe in thalassemia and allows us to obtain better-matched blood units for complicated patients.

Unlike weak D and partial D, DEL represents a weakened form of D that cannot be detected by conventional serology and requires use of an adsorption-elution method for its detection; therefore, DEL+ samples might be mistyped as D-. The study was undertaken to determine the prevalence of the DEL phenotype among D- blood donors from northern India. A total of 1003 D- blood donors were tested for weak D and DEL by the indirect antiglobulin test and an adsorption-elution method, respectively. Of the total 21,135 blood donors typed for D, 20,132 (95.3%) were D+ and 1003 (4.7%) gave a negative reaction for D. Of the total 1003 D- samples, 8 (0.8%) were weak D and only 2 (0.2%) were DEL+ by adsorption-elution testing. For samples that typed as D-, the majority of individuals (91.1%) were cde/cde (rr) followed by dCe/dce (r´r) in 4.8 percent, and dCe/dCe (r´r´) in 2.2 percent. Both DEL+ samples were also C+. We conclude that the prevalence of the DEL phenotype as detected by serology in D- north Indian blood donors wed by dCe/dce (r´r) in 4.8 percent, and dCe/dCe (r´r´) in 2.2 percent. Both DEL+ samples were also C+. We conclude that the prevalence of the DEL phenotype as detected by serology in D- north Indian blood donors is 0.2 percent, although it is as high as 2.8 percent in D-C+ individuals. There is an association of DEL with C, which can be used as a cost-effective marker for screening large numbers of D- blood donors for DEL.

The Indian blood group system (ISBT 023) comprises one lowprevalence antigen, Ina (IN1), and five high-prevalence antigens Inb (IN2), INFI (IN3), INJA (IN4), INRA (IN5), and INSL (IN6). The antigens are located on the single-pass trans-membrane glycoprotein encoded by the CD44 gene. The present study was designed to identify the prevalence of the INRA- (IN-5) phenotype and the frequency of its associated allele (IN*02.- 05) to inform us of the probability of finding antigen-negative donors and to assess the risk of antibody formation in transfusion recipients. Buffy coats were extracted from EDTA-anticoagulated whole blood samples, collected with consent from 5261 random blood donors in Surat, Gujarat, India. Standard serologic methods were performed with a modification allowing the use of antiserum generated by recycling the antibody augmented from the test already performed. A real-time polymerase chain reaction- based assay was devised to genotype c.449G>A (p.Arg150His) single nucleotide variation in sitive for the IN-5 phenotype or the allele (IN*02.-05), respectively. The allele frequency estimate ranged from less than 1 in 10,522 (0.01%) to 1 in 3203 alleles (0.03%) in the study cohort (95% confidence interval, Poisson distribution). The absence of this rare allele in the present survey could be due to an ethnic difference, since the donors mostly came from the Hindu community, and the only case of the IN-5 phenotype was found in the Muslim community. The p.150His variant may be either restricted to the index case family or only found in the Muslim community. Further studies in local subpopulations may provide more information on the frequency of p.150His and its immunogenicity in transfusion recipients if occurring among blood donors.