Comparison of serology and molecular detection of common red cell antigens in multitransfused thalassemia major and sickle cell disease patients

Molecular genotyping versus serological diagnosis for RH blood group typing in sickle cell patients

OBJECTIVES

High rate of alloimmunization in sickle cell disease (SCD) patients poses a significant challenge in finding compatible blood unit. Accurate determination of the blood group genotype of them can help reduce the alloimmunization risk. Tetra ARMS PCR is a novel method that has been utilized recently to investigate SNPs in diseases in a fast and reliable way.

METHODS

Our study included 104 SCD and sickle thalassemia (Sβ) patients referred to Baghaei-2-Hospital of Ahvaz in 2019 using a nonrandom sampling method. Blood samples were collected for serological and molecular tests. Rh genotyping was performed using Tetra ARMS PCR and compared with the serological results.

RESULTS

Based on the Tetra ARMS PCR method, out of 104 patients, 7 (6.7%) were d/d, 40 (38.5%) were D/d, 57 (54.8%) were D/D, 25 (24%) were C/C, 59 (56.7%) were C/c, 20 (19.3%) were c/c, 4 (3.8%) were E/E, 25 (24%) were E/e, and patients 75 (72.2%) were e/e. There were discrepancies in the serological and molecular results for 11 patients.

CONCLUSION

Use of Tetra ARMS PCR in combination with serological methods for determining the Rh blood group system in donors and transfusion-dependent patients represents a remarkable transformation in the field of immunohematology.

Blood transfusion dynamics in Colombia: Unveiling patterns, reactions and survival rates in multitransfused patients

BACKGROUND AND OBJECTIVES

There is no consensus on a universally accepted threshold to categorize a patient as multitransfused. In 2019, Colombia established the definition of a multitransfused patient as someone who has received six or more blood components, irrespective of the time frame. This study aims to delineate the characteristics, adverse transfusion reactions (ATRs, definitions according to the International Society of Blood Transfusion [ISBT]) and survival rates in this population.

MATERIALS AND METHODS

We performed an analysis from the data of all institutions engaged in blood component transfusions at the national level who notified events to the National Information System of Haemovigilance (SIHEVI-INS), from January 2018 to December 2022. The selection criteria focused on individuals who not only exhibited ATRs but also received six or more blood components.

RESULTS

Among the 1,784,428 patients who received 6,637,271 blood components, an average of 3.7 components per patient was noted. Concurrently, 8378 ATRs were reported (12.6 ATRs/10,000 transfused components). Within this cohort, 691 patients met the criteria for multitransfusion. Predominantly women (51.8%), these individuals received between 6 and 14 blood components. Out of the 691 multitransfused individuals who experienced ATR, 541 had an allergic reaction. Conversely, out of the 6479 non-multitransfused individuals who experienced ATR, 3835 had an allergic reaction (odds ratio: 2.49, 95% confidence interval: 2.06-3.0). Notably, 271 multitransfused individuals (39.2%) were documented as deceased, with 76% succumbing within 12 months of encountering their most recent ATR.

CONCLUSION

Multitransfused individuals in Colombia, being a high-risk group, exhibit a heightened susceptibility to allergic reactions, surpassing the frequency observed in other transfusion populations. This underscores the necessity for tailored medical care specific to this group.

Molecular typing of Kell, Kidd, and Duffy antigens in direct antiglobulin test-positive autoimmune hemolytic anemia patients

BACKGROUND

In autoimmune hemolytic anemia (AIHA) patients, conventional pretransfusion testing is difficult to interpret due to the presence of autoantibodies which may show panreactivity. Molecular phenotyping of red cell antigens could potentially be used to precisely match blood units, thereby reducing the need to perform intensive serologic laboratory testing, hence time delay in providing transfusion to such patients. The aim of this study is to perform the molecular typing for Kell, Kidd, and Duffy blood group antigens in direct antiglobulin test (DAT)-positive red blood cells of AIHA patients and provide corresponding antigen-matched blood for transfusion therapy.

MATERIALS AND METHODS

Blood samples from 50 normal blood donors and 30 DAT-positive AIHA patients were tested using standard serological techniques and polymerase chain reaction-based methods for Kell (K/k), Kidd (Jka/Jkb), and Duffy (Fya/Fyb) blood group systems. Five patients requiring blood transfusion were given donor blood units identical for Kell, Kidd, and Duffy antigens and followed up.

RESULTS

Genotyping and phenotyping results were 100% concordant for normal blood donors. Serological phenotyping of minor red cell antigens showed varied degree of agglutination for AIHA patients. The molecular typing was able to detect the antigen frequency accurately in all samples. The results of genotyping were used to provide Kell-, Kidd-, and Duffy-matched blood for transfusion therapy to AIHA patients with no adverse reaction.

CONCLUSION

Molecular blood group typing has proved immensely useful in the determination of actual antigen profile and hence in providing appropriate transfusion support in patients with AIHA reduced risk of transfusion reactions and alloimmunization.

Molecular genotyping of Indian blood group antigens amongst regular voluntary blood donors of Surat city, Gujarat, India

BACKGROUND

There is paucity of data related to the prevalence of the rare blood group antigens amongst South Gujarat blood donor population due to unavailability and high cost of antisera. Therefore it is difficult to screen donors for such rare antigens by gold standard haemagglutination assay. The single nucleotide polymorphism (SNPs) of In^a and In^b antigens is the base of the PCR based detection methods that help to detect these alleles in regular voluntary blood donors.

MATERIALS & METHODS

Blood samples of 200 unrelated regular voluntary blood donors wee collected. DNA was extracted using phenol-chloroform method and genotyped for Indian (In^a/IN*01, In^b/IN*02) blood group alleles by Sequence Specific PCR. In^a antigen positivity was confirmed by serology test.

RESULTS

Four donors were found heterozygous for In^a antigen i.e. In (a + b+) by SS-PCR and their In^a positivity were confirmed by in-house polyclonal Anti-In^a reagent. SS-PCR was standardized using known heterozygous sample of a blood donor. The frequency of In^a antigen (2.0 %) was higher than Caucasians, lower than Iranians and Arabs while comparable to those reported among Indians of Mumbai city.

CONCLUSION

In absence or unavailability of antisera particularly for low frequency alleles like In^a, such PCR based method would be extremely helpful to prepare rare donor registry by screening blood donors' at large scale. Red cells of In^a positive donors can be used as in-house reagent red cells for screening and identification of corresponding antibody.

Genotyping versus phenotyping of non-ABO erythrocyte antigens in patients with the Mediterranean hemopathic syndromes: Effect of transfusion therapy

The Mediterranean hemopathic syndromes (MHS) are the most prevalent hemoglobinopathies in the Mediterranean basin. Transfusion therapy is the main therapy for these disorders, particularly for severe forms of the disease. Currently, pre-transfusion serological typing of erythrocyte antigens is the standard tool for reducing complications of transfusion in those patients. This study compared genotyping with phenotyping of non-ABO erythrocyte antigens in patients with MHS and assessed the effect of transfusion therapy on their results. One-hundred ninety-eight MHS patients were recruited, screened, and proven negative for allo-antibodies. They were grouped into two groups: (1) 20 newly diagnosed patients with no transfusion history and (2) 178 previously diagnosed patients undergoing transfusion therapy. Patients were interviewed and clinically examined. Full blood count (FBC) and high performance liquid chromatography (HPLC) were done for group 1 only. Genotyping and phenotyping of non-ABO erythrocyte antigens were performed for group 1, and 25 patients out of group 2 were propensity score-matched (PSM) with group 1. Both groups were gender and age matched; 55% and 74% of groups 1 and 2 had major disease, respectively. Insignificant differences were observed between genotyping and phenotyping of non-ABO erythrocyte antigens in group 1, while significant discrepancies and mixed field results were noted in group 2 patients. Discrepancies were obvious with JKa, JKb, and little c antigens. Conclusively, molecular typing is a powerful tool for pre-transfusion testing in chronically transfused MHS patients. This testing reduces incidence of transfusion reactions. JKa, JKb and little c antigens are the most clinically significant non-ABO erythrocyte antigens.

Seroprevalence of HBV, HCV and HIV-1 and Correlation with Molecular Markers among Multi-Transfused Thalassemia Patients in Western India

Background

Multitransfused β-thalassemia major patients are always at high risk of having Transfusion Transmitted Infections (TTIs). This study was aimed to determine the seroprevalence of HBsAg, Anti-HIV-1/2, and Anti-HCV among these patients and to correlate the same with NAT testing.

Methods

A total of 196 patients with β-thalassemia were included in the study. Patients were screened for the presence of viral markers by third-generation ELISA test as well as for viral DNA/RNA by NAT test.

Results

Among 196 multi-transfused Beta-thalassemia patients, the seroprevalence of anti-HCV was very high 100 (51.1%), however, anti-HIV1/2 was 6 (3.1%), and HBsAg were 3 (1.5%). Surprisingly similar patterns were observed in the prevalence of molecular markers, as HCV-RNA were 66 (33.7%) of the patients along with HIV-1 RNA were 8 (4.1%), and HBV-DNA were 5 (2.5%) patients. Overall eight (4.1%) patients were found to have coinfections, where two were positive for HBsAg/anti-HCV by ELISA along with 3 (1.5%) were positive for HBV-DNA/ HCV-RNA, 1 (0.5%) was positive for HIV-RNA/HBV-DNA, and 2 (1%) had coinfection of HIV-RNA/ HCV RNA by NAT testing

Conclusion

The prevalence of HCV infection among multi-transfused β-thalassemia patients is significantly higher than that of the HBV and HIV infections. This scenario should be controlled and monitored by doing regular follow-up testing schedules of such patients and also the administration of the booster dose of the HBV vaccine along with HCV treatment with antiviral DAAs.