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BACKGROUND AND AIMS: When determining ABO antibody titers, immunoglobulin G (IgG) antibodies can be masked by immunoglobulin M (IgM) antibodies. Hence, the measurement of actual concentration of IgG requires methods like heat inactivation (HI) of plasma. This study was aimed at determining the effects of HI on IgM and IgG titers performed by conventional tube technique (CTT) and column agglutination technique (CAT). MATERIALS AND METHODS: This was a prospective, observational study conducted from October 2019 to March 2020. All consecutive A, B, and O group donors who gave consent for participation were included. All samples were consecutively tested by CTT and CAT, before and after HI (pCTT, pCAT). RESULTS: A total of 300 donors were included. IgG titers were found to be more than IgM titers. For group O, IgG titer results were higher for both anti-A and anti-B compared to group A and B. For group A, B, and O, pretreatment results were higher than posttreatment IgG titer results. Median anti-A titers were similar to median anti-B titers across all categories. Median IgM and IgG titers were higher for group O individuals than nongroup O individuals. There was reduction in IgG and IgM titers after HI of plasma. One log reduction in median titers was observed when ABO titers were performed by CAT and CTT. CONCLUSION: There is one log difference between median antibody titers estimated using heat inactivated and nonheat inactivated plasma. The use of HI for ABO isoagglutinin titer estimation can be considered in low resource settings. [ABSTRACT FROM AUTHOR]

Background and aims: In order to determine actual concentration of clinically significant IgG antibodies, there is a need to inactivate IgM antibodies, which can be performed by DTT or heat. The aim of the present study was to compare the effect of DTT treatment and heat inactivation (HI) on ABO isoagglutinin titres performed by column agglutination technology (CAT) and conventional tube technique (CTT). Materials and methods: This was a prospective, observational study conducted from October 2018 to March 2020. All consecutive O group donors were included. Serum from each donor was treated with DTT, and heat and tests were performed by CTT and CAT before and after treatment. Results: A total of 2005 donors were included. 401 (20%) samples had inter‐observer variation by CTT, and 69 (3·4%) had inter‐observer variation by CAT. Median anti‐A and anti‐B titre results were higher with CAT as compared to CTT. Median anti‐A and anti‐B IgG titre results showed a one‐ to twofold difference between CTT and CAT with higher titres reported by CAT. Median IgM titres decreased two‐ to threefold after DTT treatment, whereas onefold decrease was confirmed after HI. Concordance was found to be poor. However, correlation was found to be strong. Conclusion: There is overestimation of ABO IgG antibody titres and hence, estimation of ABO IgG titres after inactivation of IgM antibodies is strongly recommended. DTT treatment was found to be superior to HI in terms of efficiency in elimination of IgM activity. [ABSTRACT FROM AUTHOR]

Background and aims Antibody titration by the manual method has certain limitations. The aim of this study was to compare the manual conventional test tube technique (CTT) with semi-automated, column agglutination technique (CAT) and fully automated haemagglutination/solid-phase red cell adherence (HA/SPRCA) technology in measuring antibody titres of anti-A and anti-B isoagglutinins of blood group O blood donors. The median IgM and IgG antibody titres with 1+, 2+ and 3+ end-points were determined for each technology, and the agreement and correlation between results of the 3 technologies were evaluated. Materials and methods This was a prospective, observational study conducted from October 2018 to March 2020. All consecutive O group blood donors, who donated blood at the Department of Transfusion Medicine at a tertiary healthcare centre, were included in the study. All samples were consecutively tested by CTT, CAT and HA/SPRCA, and the results were recorded and compared. Results A total of 2005 donors were included. Inter-observer variation was observed in 295 (14.71%) samples by the CTT and in 51 (2.54%) by the CAT. There was 43.4% and 40.3% agreement of anti-A IgM and IgG titres between CAT (2+ strength) and CTT (1+ strength), respectively. The agreement for anti-B IgM and IgG titres between CAT (2+ strength) and CTT (1+ strength) was 43.6% and 32%, respectively. While a strong correlation was found between CTT (1+ strength) and CAT (1+, 2+ strengths) for both IgM and IgG measurements of anti-A and anti-B isoagglutinins, the correlation between CTT (1+ strength) and HA/SPRCA (1+, 2+ strengths) was found to be weak. The median IgM titres for anti-A and anti-B were lower than the median IgG titres. Conclusion The antibody titration levels were higher with CAT than with CTT, and those of HA/SPRCA were lower than those of CTT. Transfusion services need to decide which method would provide higher benefit to their patient population. [ABSTRACT FROM AUTHOR]

BACKGROUND: Erycard 2.0 is a "point-of-care" device that is primarily being used for patient blood grouping before transfusion. MATERIALS AND METHODS: Erycard 2.0 was compared with conventional slide technology for accuracy and time taken for ABO and Rh forward grouping result with column agglutination technology (CAT) being the gold standard. Erycard 2.0 as a device was also evaluated for its stability under different storage conditions and stability of result till 48 h. In addition, grouping of hemolyzed samples was also tested with Erycard 2.0. Ease of use of Erycard 2.0 was evaluated with a survey among paramedical staff. RESULTS: Erycard 2.0 demonstrated 100% concordance with CAT as compared with slide technique (98.9%). Mean time taken per test by Erycard 2.0 and slide technique was 5.13 min and 1.7 min, respectively. After pretesting storage under different temperature and humidity conditions, Erycard 2.0 did not show any deviation from the result. The result did not change even after 48 h of testing and storage under room temperature. 100% concordance was recorded between pre- and post-hemolyzed blood grouping. Ease of use survey revealed that Erycard 2.0 was more acceptable to paramedical staff for its simplicity, objectivity, and performance than conventional slide technique. CONCLUSION: Erycard 2.0 can be used as "point-of-care" device for blood donor screening for ABO and Rh blood group and can possibly replace conventional slide technique. [ABSTRACT FROM AUTHOR]

Immunohematology reference laboratory (IRL) is defined as a fully equipped advanced laboratory that receives samples from various parts of the country for workup. This is a specialized center, where other centers experiencing difficulty in resolving immunohematological tests, refer samples for further workup and resolution. To complete the workup process, ABO RhD typing, antibody screening, identification (ID), antigen phenotyping, and direct antiglobulin tests are performed. In our retrospective observational study 528 cases, worked up from October 2019 to March 2022 were included. The prevalence of alloimmunization found in this evaluation was 68.1%. Among the different alloantibodies, anti‑D was most common followed by anti‑E and anti‑M. In our study, most of the autoantibodies were of Immunoglobulin G (IgG) class (79.31%). Out of the 528 samples, ABO discrepancy was found in 48 samples (9%). Of these, none belonged to Group I or Group III discrepancy types. Group II discrepancies were noted in 28 cases (58.3%) and Group IV discrepancies were found in 20 cases (41.6%). Our study clearly indicates that there is an important role of IRL which is not only limited to ID of alloantibodies or resolution of ABO discrepancies but also supports all the hospitals and transfusion centers in the region by providing phenotype-matched or compatible units and advice for safe transfusion practices. [ABSTRACT FROM AUTHOR]

• 6678 donor blood samples were phenotyped to look for unusual phenotypes in Indian population. • Indigenous antibody screening panel was created with the help of phenotyped voluntary donor registry. • A rare donor with D - - phenotype was registered with the IRDP, Bristol, UK. A clinically significant red cell alloantibody is capable of accelerated destruction of red cells bearing the corresponding antigen. Knowledge of prevalence of these antigens is necessary for performing day to day work and for research in immunohematology. The primary aim of this study was to find the prevalence of 18 clinically significant blood group antigens in blood donors. Secondary objectives were to motivate and create a database of accessible, volunteer O blood group donors and to register rare donors with existing registries. A cross-sectional observational study was conducted in the department of Transfusion Medicine at a large tertiary care hospital in India from October 2016 to May 2018 with a planned sample size of 4800. Study population included healthy blood donors of either gender coming for blood donation to the blood centre. A total of 6678 samples were included in the study. First time donors were 21.41 % while 78.59 % were repeat donors. Voluntary donors constituted 15.81 % while replacement donors were 84.19 %. Male donors were 89.82 % while female donors were 10.18 %. The antigen, phenotype and gene frequencies were calculated. An extended phenotyped voluntary donor database was created and four rare donors were identified. One of these rare donors was registered with the International Rare Donor Panel (IRDP) and rest were registered in a local registry. This study might help enhance the confidence of blood banks in finding appropriate units for patients with unexpected antibodies or with rare phenotypes. It also paves a way for registering rare donors locally and internationally. [ABSTRACT FROM AUTHOR]

Several autoimmune disorders have been reported to be related with COVID infection. In continuation to these autoimmune phenomenon, autoimmune hemolytic anaemia (AIHA) also has been noted in COVID infected patients. The aim of the study was to find out the prevalence of red cell alloimmunization, ABO discrepancy and positive direct antiglobulin test (DAT) results in COVID infected patients hospitalised in a tertiary care centre in North India. This was a retrospective observational study done from July 2020 to June 2021. All symptomatic patients admitted to ICU tested positive for SARS CoV-2 whose blood samples were received in the immunohematology laboratory of department of Transfusion Medicine for determination of blood group and issue of packed red cells, and found to have positive antibody screen, blood group discrepancy and positive DAT results, were included in the study. A total of 10,568 tests were run, out of which 4437 were for determination of blood group, 5842 were for antibody screen and 289 were for direct antiglobulin test. Included in this study were 146 patients who either had blood group discrepancy, or had a positive antibody screen or had a positive DAT. Out of 115 positive antibody screen, 66 patients had only alloantibodies, 44 patients had only autoantibodies while only 5 patients had both auto as well as alloantibodies. Total number of positive DAT cases was 50 (50/289 = 17.3 %). There were 26 ABO discrepancies (26/4437 =0.58 %) found. Our results also indicate that there is rise in rate of alloimmunization and DAT positivity among COVID patients. [ABSTRACT FROM AUTHOR]