Antiglobulin Test Research Articles

Correlation of Capillary Tube and Transcutaneous Methods with Serum Biochemistry in Bilirubin Levels in Neonates with Jaundice

Objective: The aim of this study was to compare transcutaneous bilirubin (TcB) measurement, which is a noninvasive, easy, fast and inexpensive method in the treatment of patients with neonatal jaundice, with total serum bilirubin (TSB) measurement values, which is the standard method. Simultaneous capillary tube bilirubin values were also included in the study in terms of correlation. We investigated whether it would be safe to use TcB measurement instead of blood sampling for jaundice assessment. Materials and Methods: Between January 1, 2023 and July 1, 2023, newborns with gestational jaundice aged 37-42 weeks who were hospitalized with neonatal jaundice were enrolled in the neonatal intensive care unit of Gaziosmanpaşa University Faculty of Medicine (Tokat, Turkey). Patients with confirmed neonatal jaundice were retrospectively analyzed. Patients with antenatal or postnatal disease, ABO-Rh blood group incompatibility, and preterm-post-term neonates were excluded from the study. In addition, those who received phototherapy for the first time and did not have a history of transfusion were included in the study. Results: All 72 patients were term neonates. The mean gestational age was 37.26 weeks (range, 37-40 weeks) and the mean weight was 2789 ± 15 g (2255-4550 g). Thirty-one (43.1%) of the newborns were male. The direct Coombs test was 1+ in three newborns and 4+ in one newborn. There was a strong correlation between TcB bilirubin levels and TSB values before and after treatment (r = 0.776, p < 0.001; r = 0.773, p < 0.001, respectively). A strong correlation was observed between capillary tube bilirubin and TSB measurement values before and after treatment (r = 0.875, p < 0.001; r = 0.899, p < 0.001, respectively). Conclusion: In our study, we found a strong correlation between transcutaneous bilirubin measurement, serum bilirubin and capillary tube method performed through the ear before and after phototherapy treatment. However, due to the small size of this study, we cannot recommend the use of transcutaneous measurement alone in making treatment decisions.

Role of direct antiglobulin test in anemia under evaluation: Its prevalence, laboratory workup, and significance in further patient management-A study from eastern India.

The direct antiglobulin test (DAT) is an important diagnostic tool for immune hemolytic anemia (IHA). The present study was primarily aimed to identify the prevalence of DAT positivity in anemia patients along with its specificity . A three months follow up of the DAT positive patients were performed for the response during course of illness in terms of transfusion requirement, hemoglobin level, persistence of DAT. This cross sectional study was performed at a government medical college on symptomatic anemia patients. At initial evaluation, complete blood count (CBC), blood grouping and DAT were performed in the EDTA blood. DAT positive blood samples were analyzed for their immunoglobulin specificity, auto or alloantibody type. Acid elution and red cell phenotyping were performed wherever applicable.Their clinical presentation, hematological and biochemical parameters of hemolysis were evaluated. Statistical analysis was performed on the results on SPSS (Version 23.0;.USA) and Graph pad Prism version 9. P value <0.05 was considered significant. DAT was present in 64 out of 501 patients with male female ratio 1: 4. Warm AIHA (WAIHA) was 93.7% with secondary WAIHA 60%. IgG was associated in 86% DAT positive samples, Only C3d was 14%. All the 4 cold AIHA (6.3%) had a higher antibody titre and thermal amplitude. DAT strength was directly proportional to the degree of hemolysis. During 3 months follow up , persistence of DAT and blood transfusion requirement was more in secondary WAIHA . Hemoglobin increment was more in primary WAIHA (75%). DAT played a significant role in the diagnosis as well as evaluation of AIHA.

Pathogenetic analysis of transfusion-related acute lung injury caused by human leukocytes antigen antibody against human leukocyte antigen

From September 2019 to October 2020, pathogenetic analysis of three patients clinically diagnosed as transfusion-related acute lung injury (TRALI) caused by human leukocyte antibodies was conducted by Guangzhou Blood Centre, including 2 males and 1 female, aged 56, 50 and 20 years old, respectively. Solid phase agglutination, anti-human globulin test and flow cytometry method were used to detect the presence of antibodies against patients. Sequencing-based human leukocyte antigen (HLA-SBT) typing technique was used to detect the human leukocyte antigen (HLA) genotypes of patients. Lifecodes single antigen class Ⅰ/Ⅱ kit (LSA-Ⅰ/Ⅱ) were used to detect the specificity of HLA-class Ⅰ and class Ⅱ antibodies in donor blood by Luminex 200 liquid suspension chip system. The HLA specific antibodies and corresponding epitopes in donors were also analyzed. The results showed that HLA class Ⅰ or class Ⅱ specific antibodies against TRALI patients were detected in the blood donors. The plasma of donor 3 received by patient 1 contained antibodies against the patient's HLA-DRB1*09∶01 antigen, and the epitopes mediating the antibody reaction of the donor and recipient were 70R, 31I, 70QA. There were antibodies against the HLA-A*11∶02, HLA-A*11∶01, DRB1*12∶02, and DRB1*09∶01 antigens of patient 2 in the plasma of donor 4, and the associated antigenic epitopes were 151AHA, 57V, and 16Y. Antibodies against the HLA-DRB1*14∶04, DRB1*11∶01, and DPB1*05∶01 antigens of patient 3 were present in the plasma of donor 6 and donor 7, and the associated epitopes were 96HK, 140TV, 13SE, and 111K. Three cases of TRALI were confirmed to be caused by HLA antibodies through laboratory analysis, and human leukocyte antibody detection should be paid attention in clinically suspected cases of TRALI, and targeted diagnosis and treatment should be given.

Challenging the dogma: Red blood cell-directed autoimmunity as risk factor for red blood cell alloimmunisation after blood transfusion.

Red blood cell autoimmunity and alloimmunity are potentially linked. Quantification of this association can tailor extensively matched red blood cell transfusions in patients with autoimmunity. Using an incident new-user cohort comprising 47 285 previously non-transfused, non-alloimmunised patients, we compared transfusion-induced red blood cell alloimmunisation incidences in direct antiglobulin test (DAT)-positive and control patients. Additionally, we performed case-control analyses to handle potential confounding by clinical immunomodulators. Among (IgG and/or C3d) DAT-positive patients (N = 380), cumulative red blood cell alloimmunisation incidences after 10 units transfused reached 4.5% (95% confidence interval [CI] 2.5-8.2) versus 4.2% (CI 3.9-4.5, p = 0.88) in controls. In case-control analyses, alloimmunisation relative risks among DAT-positive patients increased to 1.7 (CI 1.1-2.8). Additional adjustments for pre-DAT transfusion exposure or the extent of Rh/K mismatching did not impact results. In conclusion, while patients with DAT positivity show an intrinsically increased alloimmune red blood cell response, their absolute risk is comparable to control patients due to counteracting co-existing immunosuppressive conditions. Consequently, isolated DAT positivity in patients lacking overt haemolysis or complicated alloantibody testing does not seem to warrant extended matching strategies.

An ongoing problem: Rhesus hemolytic disease of the newborn - A decade of experience in a single centre

BackgroundThe objectives were to evaluate the descriptive features of newborns with a diagnosis of Rhesus (Rh) hemolytic disease, to determine the morbidity and mortality rates, to evaluate the treatment methods and the factors affecting treatment requirements and clinical outcomes during a ten-year period at a tertiary center. MethodsNewborn infants who had a positive direct Coombs test and/or had a history of intrauterine transfusion (IUT) due to Rh hemolytic disease were included. The data regarding the prenatal, natal and postnatal periods were collected from hospital records. ResultsA total of 260 neonates were included of which 51.2% were female. The mean ± standard deviation gestational age was 36.9 ± 2.7 weeks. The rate of preterm birth was 41.2%. Of 257 mothers whose obstetric medical history could be accessed, 87.2% were multigravida, whereas 76.3% were multiparous. Among mothers who had a reliable history of anti-D immunoglobulin prophylaxis (n=191), 51.3% had not received anti-D immunoglobulin prophylaxis in their previous pregnancies. The antenatal transfusion rate was 31.7% and the frequency of hydrops fetalis was 8.8%. While combined exchange transfusion (ET) and phototherapy (PT) was performed in 15.4% of the babies, the majority either needed phototherapy only (51.1%) or no treatment (33.5%). The mortality rate was 3.8 % (n = 10), and nine babies out of these 10 were those with severe hydrops fetalis. ConclusionThis study showed that Rh hemolytic disease is still a major problem in developing countries. Multiple comorbidities may occur in addition to life threatening complications, including hydrops fetalis, anemia and severe hyperbilirubinemia. High rates of multiparity and low rates of anti-D immunoglobulin prophylaxis are potential barriers for the eradication of the disease. It should be remembered that Rh hemolytic disease is a preventable disease in the presence of appropriate antenatal follow-up and care facilities.

A Description of IVIG Use in Term Neonates with ABO Incompatibility.

This study aimed to determine if treatment with IVIG of neonates with ABO incompatibility (without Rh incompatibility) results in decreased number of packed red blood cell (pRBC) transfusions and phototherapy use. An Institutional Review Board (IRB)-approved, single-institution retrospective study was conducted. Neonates ≥38 weeks' gestational age born between January 1, 2007, and December 31, 2016, with ABO incompatibility were included. The comparison among groups was performed using chi-square and Fisher's exact tests for categorical variables; continuous variables were assessed by Kruskal-Wallis test. Six hundred and sixty-eight neonates with ABO incompatibility met inclusion criteria, 579 were included in the analyses. From these, 431 (74%) neonates had positive Direct Antiglobulin Test (DAT); 98 (17%) received IVIG and 352 (61%) received phototherapy. Thirty-six (6%) neonates received pRBC and 6 (1%) required exchange transfusions. Only 3 (0.5%) infants received pRBC transfusions postdischarge, by 3 months of age. Neonates requiring IVIG had lower initial hemoglobin (13.6 vs. 16.0 g/dL, p ≤ 0.0001) and higher bilirubin at start of phototherapy (9.1 vs. 8.1 mg/dL, p = 0.0064). From the 42 (7%) neonates who received simple and exchange transfusions, IVIG use was not associated with decreased use or number of transfusions (p = 0.5148 and 0.3333, respectively). Newborns with A+ and B+ blood types had comparable initial hemoglobin, DAT positivity, APGAR, and bilirubin. However, infants with B+ blood group were more likely (than A + ) to require phototherapy (p < 0.001), receive IVIG (p = 0.003), and need phototherapy for a longer duration (p = 0.001). The results of this large retrospective study reveal that giving IVIG to neonates with ABO incompatibility was associated with increased simple or exchange transfusions. Newborns with B+ blood type required more phototherapy and IVIG. Further studies are needed to better stratify neonates who would benefit from IVIG use in order to optimize treatment strategies and avoid unnecessary risks and adverse events. · IVIG use not associated with decreased use of pRBC or exchanges.. · Phototherapy duration associated with increased IVIG and pRBC use.. · Newborns with B+ blood type had worse hemolytic anemia..

The importance of removing interference caused by Darzalex® (daratumumab) in pre-transfusion testing

Introduction: Multiple myeloma (MM) is a hematologic malignacy characterized by the uncontrolled proliferation of abnormal plasma cells in the bone marrow. Darzalex® (daratumumab) has emerged as a highly effective therapeutic agent for MM, offering an additional treatment option for patients who have developed resistance to other therapies. However, the use of Darzalex® poses challenges in pre-transfusion testing due to its strong binding affinity of the monoclonal anti-CD38 antibody to CD38 protein, resulting in panreactivity with test erythrocytes and complicating the detection of erythrocyte alloantibodies. The objective of this case report is to outline the procedures, significance, and methodologies for mitigating this interference using the DaraEx® reagent. Case Report: We present the cases of three patients diagnosed with MM and treated with Darzalex® at our institution in 2023. Following the administration of Darzalex®, all three patients exhibited positive results on indirect antiglobulin tests (IAT). Cross-matching tests conducted with red blood cell concentrates also yielded positive results, with strengths ranging from 2+ to 3+. To eliminate interference, we used a specific DaraEx® reagent that utilizes Fab fragments of anti-CD38 to mitigate interference by masking CD38 on the cell surface. Subsequent application of this reagent resulted in negative IAT results for all three patients. However, one patient still displayed a weakly positive cross-matching test (&lt;1+), suggesting that complete elimination of interference may not always be achievable with the DaraEx® method. Conclusion: Despite the availability of reliable methods such as dithiothreitol and the DaraEx® reagent for mitigating interference, complete success in eliminating interference remains elusive. This underscores the importance of implementing proactive measures to prevent interference. Patients undergoing Darzalex® therapy should undergo comprehensive immunohematological testing before medication administration. Given the increased need for blood transfusions in MM patients, ensuring the compatibility of blood products is essential for safe transfusion practices.

Clinical profile and serological correlation with haemolysis in DAT-positive autoimmune haemolytic anaemia patients in Bangladesh

Discerning the type of autoimmune haemolytic anaemia (AIHA) is crucial for transfusion support and initiation of treatment. This study aimed to establish the clinical profile and serological character of red cell autoantibodies and to investigate the relationship with haemolysis in AIHA patients who were direct antiglobulin test (DAT)-positive. A total of 59 DAT-positive AIHA patients were included in this study. Clinical, laboratory and serological findings were evaluated to find the gradation of haemolysis and to investigate its correlation with age, sex, type of autoantibody and level of autoantibody. Study findings revealed that most patients (89.8%) had haemolysis, wherein moderate haemolysis (67.8%) was predominant. Weakness, palpitations, fever, pallor, tachycardia and splenomegaly were common among patients with severe and moderate haemolysis. The majority (66.1%) had an associated disorder. Warm autoantibody was the most common, followed by cold and mixed cases. The severity of haemolysis correlated strongly with the strength of the DAT reaction (Cramer V 0.636, p<0.001). These findings may be useful to clinicians while determining a treatment plan. The direct relationship between severity of haemolysis and strength of DAT needs further exploration in a large population to establish whether it can be used as a tool to formulate a treatment plan when assessing AIHA patients in low resourced countries.

Rhesus alloimmunization in pregnancy. A Tertiary Care Center Experience in Kenya. A Case Report

Background: Rhesus alloimmunization is a significant cause of perinatal morbidity in sub-SaharanAfrica.Case presentation: A 28-year-old para 2+2 gravida 5, rhesus-negative mother with no living childpresented to the Kenyatta National Hospital (KNH) antenatal clinic at 20 weeks of gestation as a referralbecause of a bad obstetric history secondary to rhesus D alloimmunization following a positive indirectCoombs test. She was started on methylprednisolone, and serial middle cerebral artery peak systolicvelocity (MCA-PSV) monitoring was performed until 32 weeks of gestation when the fetus developedhemolytic disease of the newborn diagnosed via cordocentesis. She underwent two sessions ofintrauterine transfusion and had a successful cesarean delivery at 34 weeks and 1 day of gestation. Theneonate was admitted to the KNH neonatal intensive care unit where he was managed for hemolyticdisease of the newborn, 33 days after which he was successfully discharged home.Conclusion: The role of maternal-fetal specialists in the diagnosis, antenatal follow-up, and timelymanagement of rhesus D alloimmunization is key in the prevention of adverse perinatal outcomes.

Hemolytic Disease in Newborn Due to Jka Antibody: A Unique Clinical Presentation

Hemolytic disease in newborn results from alloimmune-mediated destruction of fetal or neonatal red blood cells caused by maternal alloantibodies. While ABO and Rh (D) incompatibilities are common causes, other minor antigenic mismatches such as Kidd are relatively infrequent. Here, we report a case of a female infant displaying conjugated hyperbilirubinemia and hepato-splenomegaly. Lab tests revealed both mother’s and baby’s blood groups as A positive, along with elevated reticulocyte count and a positive direct antiglobulin test. An abdominal ultrasound unveiled inspissated bile syndrome, likely due to calcium bilirubin sludge, leading to the conjugated hyperbilirubinemia. Further assessment revealed the infant and the father had a JKa-positive RBC phenotype, while the mother had a JKa-negative phenotype. This case highlights the significance of blood group antigen beyond the Rh system as a potential cause of hemolytic disease in newborn.

The safety of ABO minor incompatible platelets transfusions using a rapid infuser.

Administering platelets through a rapid infuser is proven to be safe. However, the clinical significance of infusing ABO-incompatible platelets with red blood cells (RBCs) in a rapid infuser remains unclear. There is a theoretical risk that isoagglutinin in the plasma of a platelet unit can interact with RBCs and induce hemolysis. Seven in vitro studies were performed including five cases (type A RBCs and type O platelets) and two controls (type A RBCs and platelets). Anti-A titers were measured in platelet units. An RBC unit and a platelet unit were mixed in the rapid infuser reservoir and incubated for 30 min. The primary outcome was the presence of hemolysis based on the following parameters: free hemoglobin concentration, hemolysis check, direct antiglobulin test (DAT), and direct agglutination. The post-mix DAT was positive for IgG in all test samples (5/5), and weakly positive for complement in 3/5. The changes in free Hb in test cases between measured and calculated post-mix spanned -2.2 to +3.4 mg/dL. Post-mix hemolysis check was negative in 3/5 and slightly positive in 2/5 cases, with no significant differences compared to the control case. Anti-A titers ranged from 16 to 512 and were not associated with hemolysis. All samples were negative for direct agglutination. Our study suggested that mixing ABO-incompatible platelets with RBCs in a rapid infuser does not induce in vitro hemolysis. These findings support the use of rapid infusers regardless of platelet compatibility in support of hemostatic resuscitation.

Sequential haplo-identical conditioning transplant regimen for pediatric patients with relapsed or refractory hemophagocytic lymphohistiocytosis.

Allogeneic hematopoietic stem cell transplantation (HSCT) currently stands as the sole remedy for individuals afflicted with hemophagocytic lymphohistiocytosis (HLH). In this study, we retrospectively evaluated how pediatric patients with relapsed or refractory (R/R) HLH responded to our institution's cocktail conditioning regimen. The disease was diagnosed according to criteria applicable to patients with familial/genetic, relapsing, or severe/persistent HLH. All donors were HLA haplo-identical family donors. In our cohort, sixty-five patients (P-HLH), including 28 with familial/genetic HLH, 36 with secondary HLH, and 1 with an unknown cause, underwent haplo-identical family donor HSCT. The conditioning regimen consisted of intravenous administration of etoposide (VP-16), busulfan, fludarabine, rabbit anti-human thymocyte globulin (r-ATG), and cyclophosphamide (Cy). Tacrolimus and mycophenolate mofetil were used for graft-versus-host disease (GvHD) prevention. We observed that the median time for neutrophil recovery was 11 days (range, 8-24), and for platelet counts to exceed 20 × 109/L, it was 14 days (range, 7-130). There were 5 patients (7.7%) who experienced grades III to IV acute GvHD, and 6 patients (9.2%) developed extensive chronic GvHD. The estimated 3- and 5-year overall survival rates were 78.1% (95% CI, 65.8-84.6%) and 74.9% (95% CI, 61.2-84.4%), respectively. The estimated 3- and 5-year event-free survival rates were 73.5% (95% CI, 60.8-82.6%) and 70.3% (95% CI, 56.4-80.5%), respectively. Our findings demonstrate that our innovative conditioning regimen is both effective and safe, offering valuable insights for healthcare professionals evaluating the merits of existing therapies.

Hemolytic anemia associated with intravenous immunoglobulin in Kawasaki disease

BackgroundThe administration of high-dose intravenous immunoglobulin (IVIG) is a standard treatment for the management of Kawasaki disease (KD). IVIG is known to be a highly effective and safe treatment.Case presentationWe report the development of hemolytic anemia in seven children receiving repeated doses of IVIG. The children were aged 3–44 months and included 4 girls and 3 boys. All children received 10% IVIG and a second course of immunoglobulin because they did not respond to the first course of immunoglobulin. Two received high-dose aspirin (50 mg/kg), and five received low-dose aspirin (5 mg/kg). Two patients required additional methylprednisolone pulse therapy (30 mg/kg) after the second dose of immunoglobulin, and three patients received oral prednisolone therapy for defervescence. Three patients showed coronary artery dilation during hospitalization and normalized within two months. Pretreatment hemoglobin averaged 11.3–14.2 g/dL, and post-hemolytic anemia hemoglobin ranged from 7.4 to 9.6 g/dL, with a difference of 1.7–6.8 g/dL. Reticulocytes were increased to 3.3–13.2%. Peripheral blood smears showed normochromic normocytic anemia, and anisopoikilocytosis. All children were positive for warm-type antibodies with IgG+, C3d- in direct antiglobulin test, and the blood group was A + in five and B + in two. None of the patients received immunomodulatory therapy or red blood cell transfusions. They were followed for a year and all recovered.ConclusionEspecially, in non-O blood group KD patients who are refractory to initial IVIG and require a second dose of IVIG or 10% formulation the possibility of immune hemolytic anemia should be carefully considered, and close follow-up should be maintained after therapy.

Immune Thrombocytopenia in Children

Immune thrombocytopenia is a hematological disorder defined by an isolated decrease in platelet numbers. We present a retrospective-descriptive study that enrolls twenty-five children (aged 0-18 years old) admitted to Brasov Children’s Hospital from the 1st of January 2020 until the 1st of September 2023 with the diagnosis of idiopathic thrombocytopenic purpura (ITP).&#x0D; We could find proof of recent viral infection in seven patients out of twenty-five; three of them also had immunological findings- positive antinuclear, positive direct Coombs test, or antiplatelet antibodies. The medical literature mentions glucocorticoids and IVIG therapy as the first line of treatment for immune thrombocytopenic purpura, while new pharmaceutical agents are still under review.

Red blood cell alloimmunization in blood transfusion-dependent β thalassemia major patients in Sana’a City-Yemen

The development of erythrocyte alloantibodies complicates transfusion therapy in β thalassemia major patients. These antibodies increase the need for blood and intensify transfusion complications. Data on erythrocyte alloimmunization is scarce in Yemeni thalassemia patients. We studied the frequency of alloimmunization in multitransfused β-thalassemia major patients and investigated risk factors that affect antibody formation. Blood samples were taken from 100 β thalassemia major patients who received multitransfused leukodepleted packed red-blood cells. Antibody screening and identification were performed by indirect antiglobulin test using the gel column technique. All patients were tested for autoantibodies using autocontrol and direct antiglobulin test. No adsorption test was done as no autoantibodies were detected in any patient. In our study of 100 β-thalassemia patients, 50 were male and 50 were female with ages ranging from 1 to 30 years. Alloantibodies were present in 6% of patients, while no autoantibodies were detected. Of the 17 alloantibodies identified, the majority were directed against Kell (41.2%) and Rh (29.4%) blood groups. Alloimmunization was significantly associated with age group and sex (p = 0.013, p = 0.030), respectively in β thalassemia major patients. The development of alloantibodies was not significantly associated with duration, total number of transfusions and splenectomy (P = 0.445, P = 0.125, P = 0.647). No autoantibodies found in patients with β thalassemia major. The study found low rates of erythrocyte alloimmunization in multitransfused β-thalassemia major patients, but significant alloantibodies were produced primarily from Kell and Rh blood groups, suggesting the need for providing phenotypically matched cells for selective antigens to improve transfusion efficiency.

Validity of the current anti-D immunoglobulin doses for the prevention of hemolytic disease of the newborn in Duhok/Iraq

Abstract: BACKGROUND: The current study was initiated to evaluate the comparability of fetomaternal hemorrhage (FMH) measurement using flow cytometry (FCM) and Kleihauer–Betke test (KBT) and also to evaluate the validity of the current anti-D immunoglobulin doses for the prevention of hemolytic disease of the newborn in Duhok/Iraq. MATERIALS AND METHODS: The current study included 101 pregnant women with Rh(D)-negative blood group who had Rh (D)-positive husbands. Their blood was tested for blood groping, FMH by FCM and KBT, and indirect Coombs test, 1 h following sensitizing events and 72 h after giving anti-D. Furthermore, blood from newborns was examined for blood group and direct Coombs test. RESULTS: The main sensitizing event was parturition (62.4%) followed by cesarean section (32.7%). The indirect Coombs was positive in 32 cases while the direct Coombs test was positive in 19 cases. In 63.4% of cases, the ABO blood groups were incompatible between mothers and their babies. When FMH was checked by KBT method, it was found that 16 (15.8%) participants had FMH ranging 1.2–51 mL (median 4.35 mL), while FMH was positive in 27 (26.7%) participants by FCM method ranging 1.2–54.4 ml (median 9.5 mL). About 4–5 patients had FMH (measured by KBT and FCM, respectively) of &gt;12 mL and only 1% had a volume of &gt;30 mL. The difference between KBT and FCM for FMH measurement was statistically significant with P &lt; 0.001 when assessed by paired t-test and has a highly significant positive correlation with each other. The correlation of FMH was statistically significant with maternal gravidity, number of anti-D received before (moderate positive correlation), gestational age, and newborn hemoglobin (negative correlation). However, the correlation was not significant between FMH and the following factors: maternal parity, maternal hematological parameters, and ABO compatibility of mother and their babies with P &gt; 0.05. CONCLUSION: Inadequate doses of anti-D had been given previously that resulted in sensitization in at least one-quarter of the cases, and this necessitated proper measurement of FMH in all Rh (D) mothers following sensitizing events.

Prevalence and Clinical Significance of Immunoglobulin G1 and Immunoglobulin G3 Subclasses of Anti-D Antibody in Rh D Alloimmunized Antenatal Women

ABSTRACT Background and Objectives: Hemolytic disease of the fetus and newborn (HDFN) occurs as a result of maternal sensitization to paternal antigens. Studies have shown that the immunoglobulin G (IgG) subclass in maternal serum – particularly the presence of IgG1 and IgG3 either singly or in combination, has an impact on the presence and severity of HDFN. The column agglutination technology is used for the identification of IgG1 and IgG3 subclasses. Therefore, the prevalence of IgG1 and IgG3 subclasses in a cohort of alloimmunized Rh (D) antenatal women at our center was studied and was correlated with severity of HDFN. The aims of this study were as follows: (1) to find out the prevalence of IgG1 and IgG3 subclasses among Rh (D) alloimmunized women and (2) to assess the clinical outcome of newborns born to mothers with respect to IgG subclass. Methodology: This was a descriptive study done on 75 antenatal Rh (D) alloimmunized women who fulfilled the inclusion criteria. Blood samples from study participants were subjected to IgG subtyping using the “DAT IgG1/IgG3 ID card” (Bio-Rad, Switzerland), and the outcome of pregnancy was assessed by categorizing the newborns into mild, moderate, and severe HDFN. The data obtained were analyzed using SPSS version 16. Prevalence was calculated and severity of HDFN was correlated with subclass. Results: Among the study population, 23% of mothers had IgG1 alone. Majority (72%) had both IgG1 + IgG3 subclasses and a few (5%) had IgG2 + IgG4. When the mother had both IgG1 + IgG3 subclasses in their body most newborns had only mild HDFN. Few cases of moderate-to-severe cases of HDFN were seen. Most newborns had only mild HDFN even though there were few moderate-to-severe cases of HDFN. No significant association could be demonstrated between severity of HDFN and type of IgG subclasses. Conclusion: Majority of maternal IgG found in HDFN was a combination of IgG1+IgG3.Such cases exhibited stronger grades of reaction in Indirect Coombs Test. A significant association could not be demonstrated between severity of HDFN and type of IgG subclasses.

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

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. 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. 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. 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.

Impact of Anti-M on Grouping and Cross Matching: The Challenges Faced in Three Cases

Anti-M, a frequently encountered antibody of the MNS blood group system, is commonly regarded as a naturally occurring saline agglutinin that can occasionally exhibit clinically significant behaviour. Particularly when reactive at 37°C or during the antiglobulin phase, it can complicate pretransfusion testing and patient management in the blood bank. Three distinct cases (2 males. 1 female) in varying clinical scenarios, ranging from surgery to acute coronary syndrome, are described. The present cases presented discrepancies in blood grouping and compatibility testing, highlighting the challenges posed by the presence of Anti-M antibodies that react at or above room temperature and during the antiglobulin phase, thus defying the usual expectations. It is imperative to provide antigen-negative red cells and those that are compatible by an Indirect Antiglobulin Test (IAT) when Anti-M is reactive at 37°C to ensure safe transfusion. Hence, there is a need to underscore the potential clinical implications in transfusion medicine, as well as the nuances of detecting, identifying, and managing the presence of Anti-M antibodies in patients requiring transfusion.

Pretreatment with Daudi cells eliminates anti-CD47 monoclonal antibody interference in immunohematology testing.

Anti-CD47 monoclonal antibodies have increasing clinical applications in the treatment of cancer. However, anti-CD47 monoclonal antibodies interfere with immunohematology testing in patients who require blood transfusion. As the current approaches to removing any interferences have technical problems, new methods need to be developed to resolve anti-CD47 interference in immunohematology testing. We evaluated the Daudi cell line for the adsorption of free anti-CD47 monoclonal antibodies from patients' plasma to facilitate immunohematology testing in patients treated with anti-CD47 monoclonal antibody. CD47 expression was identified on the Daudi cells using flow cytometry and confocal microscopy. Next, we tested the ability of intact Daudi cells mixed with simulating plasma and clinical samples to achieve efficient removal of interfering anti-CD47 monoclonal antibodies. The indirect antiglobulin test was used to verify whether interference from anti-CD47 monoclonal antibodies in plasma was eliminated and whether the detection of other irregular antibodies was affected. The effect of eliminating interference was also investigated in relation to the time that the Daudi cells were stored after having been fixed with paraformaldehyde. CD47 expression was higher on Daudi cells than on red blood cells. Analysis of the indirect antiglobulin test results revealed that anti-CD47 monoclonal antibody-treated patients' plasma absorbed by Daudi cells for 15 min at 37°C could completely prevent the interference of anti-CD47 monoclonal antibodies in immunohematology testing while the detection of the tested antibodies, including anti-D and anti-K, was unaffected. By decreasing the incubation time, we discovered that interferences in samples with agglutination strengths below 2+ could be eliminated after incubation for 5 min. Of importance, Daudi cells can be preserved with 4% paraformaldehyde for 14 days as short-term storage reagents. This is the first study in which Daudi cells were used to effectively resolve the interference of anti-CD47 monoclonal antibodies in pretransfusion tests.