Dataset Information

Rh alloimmunization in chronically transfused patients with thalassemia receiving RhD, C, E, and K matched transfusions.

ABSTRACT: Chronically transfused patients with thalassemia are at risk for red cell alloimmunization. No studies have specifically examined alloimmunization after implementation of prophylactic Rh (D, C, E) and K matched red cells in a racially diverse population of thalassemia patients and donors. This retrospective study examined Rh antibodies among 40 chronically transfused patients (Asian, White, Black, Indian, Middle Eastern) with thalassemia receiving a mean of 174 serologic prophylactic RhD, C, E, and K matched red cell units. We examined the patients' RH genotype, as well as donor race and Rh phenotypes over 3 transfusion events preceding antibody detection. Eighteen alloantibodies were detected in 13 of 40 patients (32.5%), with an alloimmunization rate of 0.26 antibodies per 100 units transfused. Thirteen antibodies (72.2%) were directed against Rh (5 anti-D, 4 anti-C, 2 anti-E, 1 anti-e, 1 anti-V), despite donor phenotypes that confirmed lack of transfusion of D, C, or E antigens to patients lacking the corresponding antigen(s). Ten of 40 patients had an altered RH genotype, but the Rh antibodies were not associated with patients with variant RH. Black donors with a known high frequency of RH variants provided 63% of the units transfused in the 3 visits preceding unexplained anti-Rh detection. Rh alloimmunization not explained by the thalassemia patients' RH genotype or the donors' serologic phenotype suggests more precise matching is needed, and the role of donor RH genotypes on alloimmunization should be explored. Extending Rh D, C, and E matching to include c and e would result in better-matched units and further minimize Rh alloimmunization.

SUBMITTER: Waldis SJ

PROVIDER: S-EPMC7876880 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:Background:Molecular typing for RHCE blood group alleles has been established in many countries for patients and blood donors. In the Chinese literature nearly 80% of transfused patients with alloimmunization have antibodies specific for antigens of the Rh blood group system. We investigated if it is feasible to match packed red blood cells (RBCs) for Chinese ?-thalassemia patients by RHCE genotyping. Methods:In this study, 481 patients with ?-thalassemia were enrolled. They were genotyped for RHCE alleles by a simple PCR method with sequence-specific primers (PCR-SSP). Among these patients, 203 continuously received RBCs of the identical Rh subgroups according to the genotyping results for at least 3 months. Subsequently, their phenotypes were tested through a micro-column gel card method. For validation purposes, 400 donors were serologically typed with the same technology, of which 164 were genotyped too. Finally, the C, c, E, and e frequencies and the feasibility of the simple genotyping method were analyzed. Results:All patients showed mixed-field agglutination in the Rh subgroup gel cards before the same Rh subgroups in blood donors were selected for blood transfusion. The results, however, lacked mixed-field agglutination in all 203 cases after transfusion with RBC concentrates selected for the patient's C, c, E, and e antigens for at least 3 months. The genotyping results of 164 donors were all consistent with the serological results. Whole coding regions of RHCE were sequenced in 7 individuals with weak c, E, or e antigens. In only one sample we observed a 1059G>A nucleotide mutation coding for a truncated RhCE polypeptide (GenBank KT957625), in the other 6 samples no sequence variant was found. Both patients and donors were predominantly CcEe and CCee, with a prevalence of 55.3% and 24.9% for patients or 49.3% and 31.3% for donors, respectively. It revealed that about 80% of Chinese could receive Rh-matched RBCs easily. Conclusion:A simple RHCE genotyping technique is safe enough for Rh-matched transfusion of ?-thalassemia patients in Chinese Han.

Project description:ImportanceFollowing animal model data indicating the possible rejuvenating effects of blood from young donors, there have been at least 2 observational studies conducted with humans that have investigated whether donor age affects patient outcomes. Results, however, have been conflicting.ObjectiveTo study the association of donor age and sex with survival of patients receiving transfusions.Design, setting, and participantsA retrospective cohort study based on the Scandinavian Donations and Transfusions database, with nationwide data, was conducted for all patients from Sweden and Denmark who received at least 1 red blood cell transfusion of autologous blood or blood from unknown donors between January 1, 2003, and December 31, 2012. Patients were followed up from the first transfusion until death, emigration, or end of follow-up. Data analysis was performed from September 15 to November 15, 2016.ExposuresThe number of transfusions from blood donors of different age and sex. Exposure was treated time dependently throughout follow-up.Main outcomes and measuresHazard ratios (HRs) for death and adjusted cumulative mortality differences, both estimated using Cox proportional hazards regression.ResultsResults of a crude analysis including 968 264 transfusion recipients (550 257 women and 418 007 men; median age at first transfusion, 73.0 years [interquartile range, 59.8-82.4 years]) showed a U-shaped association between age of the blood donor and recipient mortality, with a nadir in recipients for the most common donor age group (40-49 years) and significant and increasing HRs among recipients of blood from donors of successively more extreme age groups (<20 years: HR, 1.12; 95% CI, 1.10-1.14; ≥70 years: HR, 1.25; 95% CI, 1.08-1.44). Higher mortality was also noted among recipients of blood from female donors (HR, 1.07; 95% CI, 1.07-1.07). Adjustments for number of transfusions with a linear term attenuated the associations, but the increased mortality for recipients of blood from young, old, and female donors was not eliminated. Closer examination of the association between number of transfusions and mortality revealed a nonlinear pattern. After adjustments to accommodate nonlinearity, donor age and sex were no longer associated with patient mortality.Conclusions and relevanceDonor age and sex were not associated with patient survival and need not be considered in blood allocation. Any comparison between common and less common categories of transfusions will inevitably be confounded by the number of transfusions, which drives the probability of receiving the less common blood components. Previous positive findings regarding donor age and sex are most likely explained by residual confounding.

Project description:BackgroundExisting systematic reviews of Rh immunoprophylaxis include only data from randomized controlled trials, have dated searches, and some do not report on all domains of risk of bias or evaluate the certainty of the evidence. Our objective was to perform an updated review, by including new trials, any comparative observational studies, and assessing the certainty of the evidence using the GRADE framework.MethodsWe searched MEDLINE, Embase and the Cochrane Library from 2000 to November 26, 2019. Relevant websites and bibliographies of systematic reviews and guidelines were searched for studies published before 2000. Outcomes of interest were sensitization and adverse events. Risk of bias was evaluated with the Cochrane tool and ROBINS-I. The certainty of the evidence was performed using the GRADE framework.ResultsThirteen randomized trials and eight comparative cohort studies were identified, evaluating 12 comparisons. Although there is some evidence of beneficial treatment effects (e.g., at 6-months postpartum, fewer women who received RhIg at delivery compared to no RhIg became sensitized [70 fewer sensitized women per 1,000 (95%CI: 67 to 71 fewer); I2 = 73%]), due to very low certainty of the evidence, the magnitude of the treatment effect may be overestimated. The certainty of the evidence was very low for most outcomes often due to high risk of bias (e.g., randomization method, allocation concealment, selective reporting) and imprecision (i.e., few events and small sample sizes). There is limited evidence on prophylaxis for invasive fetal procedures (e.g. amniocentesis) in the comparative literature, and few studies reported adverse events.ConclusionSerious risk of bias and low to very low certainty of the evidence is found in existing RCTs and comparative observational studies addressing optimal effectiveness of Rh immunoprophylaxis. Guideline development committees should exercise caution when assessing the strength of the recommendations that inform and influence clinical practice in this area.

Dataset Information

Rh alloimmunization in chronically transfused patients with thalassemia receiving RhD, C, E, and K matched transfusions.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets