Anti-G with Concomitant Anti-D and Anti-C in a Pre-natal Patient, in India: Multi-disciplinary Approach to Diagnosis and Management.

'G' antigen belongs to the Rh family and it was first described by Allen and Tippet in 1958. Various anti-D, anti-C, and anti-G antibody combinations can be found in patients. Ruling out the presence of anti-D is important for administering RhIg prophylaxis in RhD-negative pregnant women to prevent hemolytic disease of fetus and newborn (HDFN). RhIg prophylaxis is not indicated in the presence of an anti-D antibody. Time-to-time monitoring and follow-up of cases of RhD-negative pregnant women with a multi-disciplinary approach including an obstetrician, neonatologist, and transfusion medicine specialist helps diagnose, manage, and monitor HDFN in such cases. This case report emphasizes the need for proper antibody identification (anti-G) and managing HDFN (with intrauterine transfusions and exchange transfusion) during the perinatal period.

Comparison of Two Different Serological Viral Marker Testing Assays for Screening of Apheresis Donors: Which Assay Provides Optimum Safety for Transfusion?

While whole blood testing has evolved over the years, viral marker testing for plateletpheresis donors is still performed by Rapid Diagnostic Tests (RDT). Aim of this study was to compare diagnostic accuracy of RDT and Chemiluminescence Immunoassay (CLIA) in serological testing for HBsAg, anti-HCV and anti-HIV antibodies. A prospective, analytical study was conducted in the department of Transfusion Medicine at a tertiary healthcare center in India between September 2016 and August 2018. Samples were simultaneously tested by CLIA, RDT and a confirmatory test. Sensitivity, specificity, negative and positive predictive values and mean time taken to report results were calculated. A total of 102 (1.48%) of the 6883 samples were found to be reactive by either or both the assays. A total of 74 (1.08%) samples were HBsAg reactive, 23 (0.33%) were reactive for anti-HCV antibodies and 5 (0.07%) were reactive for anti-HIV I and II antibodies. A combined sero-prevalence of 1.05% (72) was observed; 0.78% (54) for HBsAg, 0.26% (18) for anti-HCV antibodies and none for anti-HIV I and II antibodies. Four (3.85%) reactive samples were missed by RDT and therefore sensitivity of RDT was quite less as compared to CLIA. RDT and CLIA both were found to have a statistically significant shorter turnaround time than confirmatory tests. There is increasing need to develop a safe donor screening strategy for plateletpheresis. CLIA offers an excellent alterative to RDT for viral marker testing in terms of sensitivity.

Development and validation of novel kit for quantification of SARS-CoV-2 antibodies on clinical samples.

Since the pandemic occurred due to the emergence of SARS-CoV-2, there has always been a demand for a simple and sensitive diagnostic kit for detection of SARS-Cov-2 infection. In January 2020, WHO approved the Reverse Transcriptase Polymerase Chain Reaction (RT-PCR) for detecting the presence of Covid-19 genetic material in individuals. Till date many diagnostic kits have arrived in the market for quantification of SARS-CoV-2 antibodies. In spite of being the gold standard method of Covid-19 detection, there are some drawbacks associated with RT-PCR which leads to false-negative results. Hence, in order to fulfil the need for an antibody testing kit for evaluating seroconversion and immunity acquisition in the population, an efficient, highly specific and sensitive assay, Chimera Soochak, an enzyme-linked immunoassay (ELISA) Kit has been developed. It works on the principle of detecting IgG antibodies developed specifically against the S1-RBD by employing a recombinant strain of S1-RBD produced in the HEK293 cell line. The developed kit was validated using different modes and methods to attain the utmost confidence on the samples collected from patients. The validation methodology included, validation with known samples, blind study, third-party validation, validation using WHO Reference Panel and comparison with FDA approved Surrogate virus neutralization kit. The kit was found successful in detecting IgG against the S1-RBD of SARS-CoV-2. The kit had been validated on multiple parameters. A total of 900 samples had been tested by using this kit and it has exhibited the sensitivity, specificity and accuracy for all the above-mentioned parameters.

Comparison of in-vitro and in-vivo parameters of whole blood derived random donor platelets (RDP) after over-night hold with RDP prepared after 2-h hold: Single centre report from India.

BACKGROUND: Random Donor Platelet (RDP) derived from whole blood is the major source of platelets in India. At our centre, we prepare RDPs by buffy coat method after a holding period of 2-hours (THRDP) as per current regulatory guidelines. Overnight hold of buffy coats before RDP preparation (OHRDP) would logistically optimise the manpower usage at our centre. The aim of this study was to compare both in-vitro as well as in-vivo parameters of OHRDPs with THRDPs. METHODOLOGY: Hematological (Platelet, leucocyte counts), physical (pH and Swirling) and biochemical parameters (pO2, pCO2, lactate, bicarbonate and glucose) as well as platelet activation markers were tested in THRDPs and OHRDPs each at Day-1 and Day-5 as in-vitro studies. Separately, in-vivo study was done where Corrected count increment (CCI) and percentage platelet recovery (PPR) were considered. All parameters were expressed as Mean ± Standard deviation and were analysed using paired t-test with level of significance, p < 0.05. RESULTS: OHRDPs had higher platelet counts and lower leucocytes and CD62 P expression than THRDPs. All other markers were well within the quality control range in both groups. No significant differences were seen in the two groups when comparing CCI and PPR. CONCLUSION: OHRDPs were found to be as good or better as compared to the THRDPs in the in-vitro part of our study. Additionally, there were no significant differences between the two groups when they were compared in vivo. This makes us conclude that overnight hold of buffy coats may be implemented at our center.

Correlation of sample-to-cut-off ratio of anti-SARS-CoV-2 IgG antibody chemiluminescent assay with neutralization activity: a prospective multi-centric study in India.

Background and Objectives: There are limited published data on association of results from commercial serological anti-SARS-CoV-2 IgG antibody CLIA (chemiluminescent immunoassay) assays with neutralizing antibodies. This study was undertaken with an objective to correlate sample-to-cut-off (S/Co) ratio of CLIA antibody tests with inhibition activity, which may then serve as a valuable guide for labelling plasma as COVID convalescent plasma (CCP) for therapy and assessing vaccine efficacy. Materials and Methods: A total of 139 donor serum samples who were previously RT-PCR positive and had recovered completely from COVID-19 at least 28 days prior to collection of samples were recruited at three sites. The samples were analysed for S/Co ratio and per cent inhibition activity with VITROS SARS-CoV-2 IgG chemiluminescent assay and GenScript cPass SARS-CoV-2 Surrogate Virus Neutralization Test (sVNT) kit, respectively. Linear regression equation and receiver operating characteristic (ROC) curve were used to check the proposed model of comparing S/Co with per cent inhibition. Results: The results indicate very good correlation between the S/Co ratio of the chemiluminescent IgG assay and the neutralization activity depicted by per cent inhibition on sVNT assay. S/Co ratio of 4·04 (low-titre) and 8·19 (high-titre) correlated with 30% and 68% inhibition, respectively. Conclusion: Chemiluminescent SARS-CoV-2 IgG assay can be used as a semi-quantitative test, with a cut-off of >8·19S/Co ratio for selecting donors for convalescent plasma therapy and assessing efficacy of vaccination.

A case report of multiple Rh alloantibodies in a pregnant female: Resolution by sequential adsorption.

Anti-G antibody mimics the reactivity pattern of coexistent anti-D and anti-C. Differentiating between the two is significant in antenatal females where the decision to administer RhD prophylaxis is based on the presence or absence of anti-D antibody. The aim of reporting this serological challenge is to emphasize the need for phenotyping red cells for sourcing appropriate in house red cell reagents and to help transfusion services sharpen problem-solving skills. A 26-year-old pregnant female with a complicated obstetric history and a positive indirect antiglobulin test presented to the hospital for antenatal assessment at 24 weeks. A positive antibody screen warranted identification of the implicating antibodies. Since identification was suggestive of multiple alloantibodies whose specificities could not be confirmed, step-wise sequential adsorption and elution was required. Anti-D, anti-C, and anti-E antibodies were identified in patient plasma with titers of 1024, 4, and 32, respectively. The absence of anti-G was also confirmed. Multiple alloantibodies can pose a challenge to transfusion services. However, with the help of select cells, phenotyping, adsorption elution studies, and phenotyped donor units; solving complex serological cases can be accomplished.

Peripheral blood stem cell mobilization with pegylated granulocyte colony stimulating factor in children.

BACKGROUND AND AIM: We report here our experience of using pegylated granulocyte colony stimulating factor (peg-GCSF) for peripheral blood stem cell (PBSC) mobilization in children. METHODS AND RESULTS: A total of nine children suffering from high-risk/relapsed solid tumors were mobilized with chemotherapy and peg-GCSF (100 microgram/kg single dose). Mean age was 7.7 years (range 2-15 years).The mean time from peg-GCSF administration to PBSC harvest was 9.7 days. Adequate stem cells (median dose 26.9 million/kg) could be harvested in all children by a single apheresis procedure. No major adverse events observed. CONCLUSION: It is feasible and safe to mobilize PBSC with peg-GCSF in children with cancer.

Patient blood management in India - Review of current practices and feasibility of applying appropriate standard of care guidelines. A position paper by an interdisciplinary expert group.

In a developing country like India, with limited resources and access to healthcare facilities, dealing with massive hemorrhage is a major challenge. This challenge gets compounded by pre-existing anemia, hemostatic disorders, and logistic issues of timely transfer of such patients from peripheral hospitals to centers with adequate resources and management expertise. Despite the awareness amongst healthcare providers regarding management modalities of bleeding patients, no uniform Patient Blood Management (PBM) or perioperative bleeding management protocols have been implemented in India, yet. In light of this, an interdisciplinary expert group came together, comprising of experts working in transfusion medicine, hematology, obstetrics, anesthesiology and intensive care, to review current practices in management of bleeding in Indian healthcare institutions and evaluating the feasibility of implementing uniform PBM guidelines. The specific intent was to perform a gap analysis between the ideal and the current status in terms of practices and resources. The expert group identified interdisciplinary education in PBM and bleeding management, bleeding history, viscoelastic and platelet function testing, and the implementation of validated, setting-specific bleeding management protocols (algorithms) as important tools in PBM and perioperative bleeding management. Here, trauma, major surgery, postpartum hemorrhage, cardiac and liver surgery are the most common clinical settings associated with massive blood loss. Accordingly, PBM should be implemented as a multidisciplinary and practically applicable concept in India in a timely manner in order to optimize the use the precious resource blood and to increase patients' safety.

Immuno-hematological consequence of intravenous drug abuse?

Intravenous (IV) drug abuse has been well established to be the source of transfer of infections, such as HIV, hepatitis C virus, and hepatitis B virus. However, often overlooked fact is that IV drug abusers have a potential for developing alloimmunization due to universal practice of flushing/washing out the syringe by own blood to rinse out the drug in the syringe. We present here a case of a 28-year-old man who presented with a rather unique predicament of having developed four different alloantibodies after exposure to allogenic blood through IV drug abuse. This case was detected promptly due to routine usage of type and screen policy for all the patients receiving transfusion. Such screening for atypical antibodies must be instituted to preemptively identify these antibodies and arrange compatible blood, which could have been difficult otherwise, at short notice during routine crossmatch. This is the first of its kind case ever reported from India and has no precedence.

Patient blood management in a patient with multiple red cell antibodies (anti-C, anti-e, and anti-K) undergoing liver transplant in South India: A team approach.

End-stage liver disease (ESLD) patients undergoing liver transplant (LT) surgery are often multiply alloimmunized and pose significant challenges to the transfusion services in terms of red cell cross-match incompatibility, unpredictable blood requirements, and often lead to significant delays in availing compatible red cell units. We report a case of a 64-year-old female from Bahrain, a known case of hepatitis C-related ESLD referred for LT surgery. She had a history of multiple uneventful transfusions in the preceding year. Her blood group was A-positive, direct antiglobulin test, and cold antibodies were negative. Indirect antiglobulin test was positive, and antibody identification confirmed the presence of anti-C, anti-e, and anti-K. Her red cell phenotype was R2R2 and Kell negative (C-c+E+e-K-). The patient was started on erythropoietin. Requests for R2R2 and Kell negative units were sent to various blood banks across the country. After >800 A/O group units phenotyping and a waiting period of 6 weeks, two compatible R2R2 phenotypes and Kell negative could be arranged in-house and three units were received from Gurgaon, North India. Intraoperative management included blood preservation techniques including cell salvage, antifibrinolytic drug, and monitoring using thromboelastography. The estimated blood loss was 350 ml with pre- and postoperative Hb 10.4 gm% and 9.2 gm%, respectively. She received intraoperatively two units of single-donor platelet and four units of fresh frozen plasma and postoperatively one unit of leukocyte-depleted-packed red cells and doing well at 12-month follow-up. This case highlights the importance of advance immunohematology for timely detection of alloimmunization and providing antigen-negative compatible units, proper communication between the transfusion specialists, and the clinical team for proper patient blood management as well as the need for central rare donor registry program to avoid delays in providing compatible blood in such inevitable cases.

An algorithmic approach to serological work-up of ABO sub-groups which present as ABO discrepancies in resource constraint settings.

BACKGROUND: ABO subgroups or weaker variants of A or B are group A or B subjects whose erythrocytes give a weak or negative reaction serologically with anti-A or Anti - B antisera respectively. Occurrence of these subgroups may lead to an ABO discrepancy which often puts transfusion services in a quandary. ABO subgroups which present as ABO discrepancies can be missed if reverse grouping is not performed. AIM: This study was planned to estimate the prevalence of different subgroups which can present as an ABO discrepancy in Indian population, and provide an insight to transfusion services for identification of subgroups serologically. MATERIALS AND METHODS: A cross-sectional, analytical study was performed at a tertiary healthcare based blood bank on whole blood donors and patients from January 2017 to July 2018. All suspected type II and Type IV (with Anti-A1) ABO discrepant samples were projected to an algorithmic testing process, to confirm discrepancy and then narrow down to the probable subgroup. RESULTS: A total of 33 subgroup discrepancies; 26 of A group and 7 of B group were identified out of 73,380 patient and 35,279 donor samples tested for blood grouping. Following the algorithm, the overall prevalence of weak subgroups which can present as an ABO discrepancy was found to be 1 in 3293 or 0.03% in our population by serological testing. Out of the discrepancies caused by subgroups, the prevalence of subgroups of A were 0.0101%, 0.0018%, 0.0009%, 0.0027%, 0.0027% and 0.0018% for A2 with anti-A1, A3, Aend, Ax, Am and Ael respectively while those of B were 0.009%, 0.0009%, 0.0009% and 0.009% for B3, Bx, Bm and Bel respectively. CONCLUSION: Algorithmic approach for resolution of ABO discrepancies caused by subgroups helps in identifying the subgroup which is important because these individuals may be mistyped as group O individuals.

Routine indirect antiglobulin testing of blood donors-a further step toward blood safety: an experience from a tertiary care center in northern India.

CONCLUSIONS: This scientific article emphasizes the importance of a policy for antibody screening of all blood donors as a step to further improve blood safety. We also report the incidence of red blood cell (RBC) alloimmunization in healthy blood donors obtained using a cross-sectional prospective study from September 2017 to January 2019 in the Department of Transfusion Medicine of a tertiary care referral and teaching institute in northern India. The indirect antiglobulin test (IAT) for unexpected RBC antibodies was performed by the conventional tube test with pooled group O RBCs on all donor units irrespective of their D status. Samples with positive IATs were sent to the Immune Hematology Reference Laboratory for further immunohematolo-gy workup, maintaining predefined optimal storage and transport conditions. Of the 10,390 donors studied, 9959 were males and 431 were females. The incidence of unexpected antibodies (antibodies other than those of the ABO blood system) among the blood donors was found to be 0.18 percent (19 of 10,390 with 25 alloantibodies). Of the 19 alloimmunized donors, 16 (84.2%) were male (alloimmunization rate 0.16%, 16 of 9959) and 3 (15.8%) were female (alloimmunization rate 0.69%, 3 of 431) (p = 0.01; chi-square test). In our study, the most frequent alloantibodies identified were of the Lewis blood group system (17 of 25 [68%] in 14 of the 19 alloimmunized donors). The second most common allo-antibodies belonged to the Rh blood group system (4 of 25 [16%] in 3 of the 19 alloimmunized donors), followed by those of the MNS blood group system (3 of 25 [12%] in 2 of 19 alloimmunized donors). Anti-K was found in one donor (1 of 25 [4%]). Based on the results of the study, we recommend that a policy of routinely performing IATs on all donor units, irrespective of their D status, be adopted as an essential component of safe blood transfusion practices.

Utility of grey zone testing strategy in transfusion transmissible infection testing in blood bank is of limited value!

Several blood banks use grey zone (GZ) phenomenon (defined as samples with optical density within 10% below the cut off in enzyme immuno-assay [EIA]/chemiluminescence immunoassay [CLIA]) to further augment blood safety. There is paucity of data regarding usefulness of GZ sample and its application in Transfusion Transmissible Infection (TTI) screening procedures in blood transfusion services. We looked at our GZ sample results and their confirmatory test results to verify if it adds to blood safety in our set-up? We performed a prospective analytical study on blood donors' samples over two years. All the donors' samples were screened for TTI using CLIA. Samples with signal/cut-off ratio between ≥0.90 and <1.00 were classified under GZ. They were re-tested in duplicate and submitted to confirmatory testing: Neutralization Test for HBsAg, Immunoblot for HCV, and Western blot for HIV. Among the 50,064 blood donors donating the blood during study period, 573 (1.14%) donors were reactive for HBsAg, HCV, and HIV. Forty-seven (0.1%) TTI samples were GZ, but none was "confirmed positive." The utility of GZ testing seems to be limited. However, this may be continued for sake of "erring on the side of caution" and since this only results in negligible wastage (0.1%) of blood units.

Automated-red cell exchange for methaemoglobinaemia in a G6PD-deficient patient.

Methaemoglobinaemia in G6PD deficiency can be managed by oxidizing agents such as methylene blue and red cell exchange (RCE). We describe a G6PD-deficient patient who presented with oxidative stress with methaemoglobinaemia and was successfully managed with automated-RCE. At presentation, the patient had anaemia, was restless, was tired and had dyspnoea. Co-oximetry showed methaemoglo-binaemia of 10.1 U/g. Further testing revealed the patient had insufficient quantities of G6PD enzyme activity (0.1 U/g Hb). In view of methaemoglobinaemia, severe G6PD deficiency and signs of haemolysis, therapeutic RCE was planned. The patient underwent two automated-RCE procedures on consecutive days, bringing down his methaemoglobin levels from 12.5 to 0.1 U/g. In each procedure, 1.5 volumes of RCE at 100% balance rate was performed using 5 units of red blood cells. The patient responded well to RCE and other supportive treatment and was off medication and doing well at day 100 of follow-up.

A guide to organize voluntary stem cell donors recruitment drive for hematopoietic progenitor stem cell transplant.

BACKGROUND: Hematopoietic progenitor cell transplantation (HPCT) is used as a definitive treatment in hematological malignancies. For a successful HPCT, the donor and recipient should have matching human leukocyte antigens (HLAs). About 25% of patients have a chance of finding matching HLA within family, while rests 75% are dependent on voluntary stem cell donor. Globally, there are 75 stem cell registries with more than 30 million donors registered among which India represents 0.36 million. Therefore, finding a stem cell donor for Indian patient is quite difficult. The aim of the present study is to discuss the significance of voluntary stem cell donor recruitment drive and also to guide the drive organizers and their team for effectively organizing the drive to increase the database of such donors. MATERIALS AND METHODS: Voluntary stem cell donor recruitment drives are conducted to spread awareness among the people and motivate them to register as a donor. Once the donors have given their consent, the sample is taken and sent to laboratory for HLA typing and the result is uploaded in World Marrow Donor Association, an international association of member to find the best possible matches for patients with hematological disorders. RESULTS: Genebandhu has organized over 127 recruitment camps since 2012 and recruited 13,000 voluntary stem cell donors. HLA typing of 7446 donors has been completed. Out of this small number of typed donors, 11 lifesaving HPCTs have been successfully facilitated. CONCLUSIONS: Here, we have demonstrated guidelines along with steps to organize voluntary stem cell donors recruitment drive that is needed to increase number of donors, thus increasing significantly the chances of saving many vital lives.

Successful treatment of Sezary syndrome with extracorporeal photopheresis - The first attempt in India.

Sezary syndrome (SS) is more aggressive leukemic variant of cutaneous T-cell lymphoma in which a significant number of circulating malignant (Sezary) cells are observed in peripheral blood. Although single-agent or combination chemotherapy regimens have produced moderately high response rates in patients with advanced-stage SS, these responses are invariably not durable. Extracorporeal photopheresis (ECP) is recommended as an immunomodulator treatment, offering better life quality for patient. We would like to present the first SS case treated successfully with low-dose methotrexate and ECP in India. A 50-year-old male presented with rash and severe pruritus all over the body for 2 years. He had received various treatment regimens but without any symptomatic improvement. He underwent detailed examination and diagnosis of SS was established. Peripheral smear revealed total leukocyte count of 14900/µl with 55% cells reported as Sezary cells. Contrast-enhanced computerized tomography revealed few insignificant (<1.5 cm) bilateral nodes in the axillary and inguinal region. The patient's disease stage was determined IVA1, and grade was T4N0M0B2. He received six cycles of CHOP, which led to a short-term remission of <3 months, and he was started on single-agent methotrexate along with skin supportive treatment. He did not respond to low-dose methotrexate alone, and therefore, ECP was added to treatment regimen. This was possibly the first such treatment for SS patient in India. The patient had very good response after six cycles of ECP with pruritus and itching diminishing and scaly lesions down to <10% of body surface area. There was regrowth of hair all over affected area. Sezary cell counts also came down to 35%. The patient continues to do well post-ECP, with single-agent gemcitabine. ECP either as monotherapy or in combination with other immunotherapies offers a good treatment option to otherwise resistant cases of SS.

Matched unrelated donor hematopoietic progenitor cell transplantation: A report based on a single registry in India.

INTRODUCTION: Currently, more than 10,000 matched unrelated donor transplants (MUDT) are performed annually worldwide. India has recorded a significant increase in the number of hematopoietic progenitor cell transplantation (HPCT) centers reporting transplants. The number of HPCTs increases by approximately 10% every year, with 1878 transplants reported by Indian stem cell transplant registries in 2016. However, published outcome data of MUDT in India are scant, with reports limited to autologous and allogenic matched unrelated transplants, which motivated us to present our MUDT data. AIMS AND OBJECTIVE: To review the operations, and more importantly, the patient outcome data of a new registry in India. MATERIALS AND METHODS: We accessed an Indian HLA donor database with high-resolution HLA typing results of 7682 (until 31st July 2018) volunteer HLA donors. The typing results were uploaded to proprietary software. The search result was considered a "match" when a 10/10 potential HLA match was found. Patients who were found to be alive through mail communication and did not exhibit signs and symptoms of disease were considered to have disease-free survival (DFS). RESULTS: During the six years of operations of the database, 1165 searches resulted in 68 10/10 matches from the registry. Of these, 11 were MUD HPCT records. At a minimum follow-up of almost 11 months, seven recipients continue to exhibit DFS. CONCLUSIONS: The patient DFS data prove that even a small registry with slightly more than 7000 donors can yield reasonably good patient outcomes.

Applying newer parameter Ret-He (reticulocyte haemoglobin equivalent) to assess latent iron deficiency (LID) in blood donors-study at a tertiary care hospital in India.

BACKGROUND: It is important to detect Latent Iron Deficiency (LID) to prevent development of an overt iron deficiency anemia. Early detection is difficult by using conventional hematological and biochemical parameters. Soluble transferrin receptor (sTfR) is presently the gold standard for diagnosing LID. We evaluated the utility of Reticulocyte Hemoglobin Equivalent (Ret-He), a newer hematological parameter, to predict LID in blood donors as compared to sTfR. METHODS: This was a randomized prospective study performed on 501 donor samples over a period of three-months. All donors were included after administering medical history questionnaire and a brief physical examination in accordance with national guidelines (Hb ≥12.5). Additional samples were collected during donation according to the institutional standard operating procedure (SOP). All hemograms were performed on the Sysmex XE-2100 analyzer which included Ret-He. sTfR was measured in batch assays by ELISA (Biovendor, Czech Republic). Ret He <28 pg and sTfR≥3µg/ml were used to diagnose LID. Serum Iron, Total Iron Binding Capacity (TIBC) and Serum Ferritin were also measured simultaneously. RESULTS: Of the 501 blood donors, sTfR and Ret-He detected LID in 148 and 135 donors respectively. In comparison to sTfR, Ret-He had sensitivity of 92.7%, a specificity of 97.16%, PPV of 93.1% and NPV of 96.3%. Serum Ferritin, TIBC and serum Iron had comparatively lower sensitivity of 87.16%, 79.7% and 77.7% respectively. CONCLUSION: Ret-He can be used as a routine screening test to detect LID in blood donors. This could provide an opportunity to make appropriate and timely interventions like dietary changes or drug supplementation.

Clinically significant naturally occurring anti-N and anti-S in a blood donor: a rare finding.

CONCLUSIONS: To the Editors: Alloimmunization is triggered when an individual whose red blood cells (RBCs) are lacking particular antigens is exposed to these antigens through transfusion or pregnancy, causing the formation of immune antibodies. In addition to these exogenous exposures, underlying inflammatory or autoimmune conditions may lead to formation of unexpected antibodies. Individual factors also play a role, since some people are responders and others are non-responders. We report a case of naturally occurring alloanti-N and alloanti-S in a healthy D+ blood donor. Both antibodies were reactive over a wide thermal amplitude and hence were potentially clinically significant. This case highlights the importance of incorporating the indirect antiglobulin test (IAT) to test for unexpected RBC antibodies for all blood units as a routine protocol.