Positive Direct Antiglobulin Test Research Articles

Autoimmune Hemolytic Anemia Associated with Mature Ovarian Cystic Teratoma Containing Monoclonal Immunoglobulin G: A Case Report and Review of Literature

Background. Autoimmune hemolytic anemia (AIHA) associated with solid tumors such as mature cystic teratomas is rare and poorly understood. Here, we report a successfully treated case of secondary AIHA in a mature cystic teratoma containing antibodies against red blood cells. Case description. A 22-year-old woman was referred to our hospital with progressive anemia. Laboratory findings revealed hemolysis with a positive direct and indirect antiglobulin test. Imaging studies identified a left ovarian mass, suspected to be a mature cystic teratoma, which was later confirmed by histopathology after laparoscopic oophorocystectomy. The patient was treated with prednisolone, resulting in improved anemia. To examine the relationship between the tumor and AIHA, an indirect antiglobulin test was performed on the tumor contents. Stronger aggregations were observed at any concentration diluted by 10 times from 10 to 10,000 times of the tumor contents compared to the patient’s serum. Additionally, immunofixation electrophoresis of the tumor contents revealed the presence of monoclonal immunoglobulin G-κ. Conclusion. The presence of monoclonal IgG-κ in the tumor suggests intratumoral antibody production as a possible mechanism. Further research is necessary to elucidate the pathogenic relationship between such tumors and AIHA. The report also highlights the importance of considering secondary AIHA in patients with unexplained anemia and solid tumors.

Pre-transfusion compatibility tests in Malagasy sickle cell patients

Introduction: Blood transfusion is a key component of sickle cell disease management. However, iterative transfusions of labile blood products for sickle cell patients increase the risk of anti-erythrocyte alloimmunization. It is usual to perform pre-transfusion compatibility tests in order to check ABO compatibility and to detect the possible existence of irregular antibodies in patients against the donor's antigens. Methods: This is a prospective and descriptive study dealing with pre-transfusion compatibility tests over a 3-month period, from September 2018 to November 2018, at the Regional Blood Transfusion Centre (CRTS) of Analamanga Region, the capital of Madagascar. Results: We included 33 out of 113 patients during the study period. Compatibility test was positive in 21.21%, of all tested samples. Major and minor compatibility tests were positive alone respectively in 6.25% and 12.50%. And both were positive in 3.12%. The self-test was positive in 3.03% with a positive direct antiglobulin test. Positive compatibility tests were more frequent in patients who received more than two transfusions. Compatible blood bag for the patient was found after testing 2 donor pockets in 27.27% of cases, and after testing 3 pockets in 3.03%. Conclusion: Pre-transfusion compatibility tests are essential and have to be performed systematically on each blood bag before any transfusion. They are used to identify the presence of alloantibodies and provide compatible blood products to patients.

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.

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.

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..

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.

Phase I Study of Response-Adapted Treatment with Venetoclax, Obinutuzumab, and Magrolimab (VENOM) in Relapsed and Refractory Indolent B-Cell Malignancies

Background and Significance Targeted agents and immunotherapy have changed the treatment landscape for follicular lymphoma (FL), mantle cell lymphoma (MCL), marginal zone lymphoma (MZL), and chronic lymphocytic leukemia (CLL), but indefinite therapy leads to cumulative toxicity and excessive cost. CD47 is a checkpoint for the innate immune system providing an inhibitory signal to phagocytic macrophages and a rational therapeutic target in B-cell lymphoma. Magrolimab is a fully humanized IgG4 anti-human CD47 antibody, with high activity in FL when combined with rituximab (Advani NEJM 2018). Our objective is to test the safety of adding escalating doses of venetoclax to magrolimab and obinutuzumab in a response-adapted study design with planned dose expansion cohorts (www.clinicaltrials.govidentifier NCT04599634). Study Design and Methods Patients with grade 1-3A FL, MCL, MZL, or CLL relapsed after and/or refractory to ≥2 prior lines of therapy are eligible. Pts with FL are eligible after 1 prior therapy if FLIPI ≥2 or disease progression within 24 months of the end of the last therapy. Pts with MCL are eligible after 1 prior therapy if blastoid histology, 17p deletion, TP53 mutation, Ki67 ≥30%, or received Bruton's tyrosine kinase inhibitor (BTKi) as first-line therapy. Pts with CLL are eligible after 1 prior therapy if 17p deletion, TP53 mutation, or received both a BTKi and a BCL2 inhibitor. Eligibility includes age ≥18 and adequate organ function unless dysfunction secondary to lymphoma. A positive direct antiglobulin test without hemolytic anemia is allowed. Patients with a history of hemolytic anemia or autoimmune thrombocytopenia within 3 months of enrollment are excluded. No washout period is required for prior anti-lymphoma treatment. Active HIV, CMV, and hepatitis B or C are excluded. The safety of venetoclax, obinutuzumab, and magrolimab will first be determined in 2 dose-finding cohorts of up to 24 pts (Cohort 1: 6-12 pts with FL and Cohort 2: 6-12 pts with MZL, MCL, or CLL). During dose-finding, all pts start triplet therapy with venetoclax, obinutuzumab, and magrolimab (Figure 1). Magrolimab IV is administered at a 1mg/kg priming dose on D1 of the first cycle, followed by 30mg/kg x 3 weekly loading doses, then 30 mg/kg on D1 of each 4-wk cycle. Obinutuzumab IV is administered at 100mg on D1, 900mg on D2, and 1000mg on D8 and D15 of the first cycle, followed by 1000mg on D1 of each 4-wk cycle. Pts with FL receive venetoclax 800mg (DL1) daily throughout therapy duration, whereas pts with MZL, MCL, and CLL start venetoclax at 20mg with weekly escalation to 400mg (DL1) over 5 weeks. Dose-limiting toxicity is assessed during the first 4 wks for FL, and the first 5 wks for MZL, MCL, and CLL. If ≥2 of 6 pts in either arm experience DLT, 6 additional pts will be enrolled to the respective arm at DL(-1) of venetoclax (600mg for FL and 200mg for MZL, MCL, and CLL). After dose-finding is completed, expansion cohorts of each histology will first receive magrolimab and obinutuzumab for two 4-wk cycles in a window for translational research. On-treatment tumor biopsies are optional during the window. After the window, venetoclax will be added at the dose determined during dose-finding. FDG-PET and CT scans are performed at baseline, after window, and after cycles 3 and 6 of triplet therapy. During both dose-finding and dose-escalation, pts with complete response (CR) after 6 cycles of triplet therapy will stop therapy. If these pts relapse, they can be retreated with an additional 6 cycles of triplet therapy. Pts with partial response (PR) after 6 cycles of triplet therapy receive an additional 6 cycles of triplet therapy. All pts stop treatment after 12 cycles. The primary objective is safety, with secondary endpoints of overall response rate, duration of response, and PFS. Exploratory objectives include the identification of a molecular signature that predicts response to magrolimab and obinutuzumab, and correlation of response with circulating tumor DNA levels.

Positive-DAT and autoimmune manifestations in patients with JAK2V617F mutation

Objective: Myeloproliferative neoplasms (MPN) are occasionally associated with autoimmune manifestations. The prevalence of positive direct antiglobulin test (DAT) in patients with JAK2V617F mutation is not yet known. Methods: We conducted a cohort study of all consecutive patients with JAK2V617F mutation who underwent DAT at presentation from 2010 to 2022. We also looked for the prevalence of autoimmune diseases (AIDs) and relation to thrombosis. Results: Fifty nine patients formed the cohort, 22 females and 37 males, with a mean age of 65 years. The median follow-up time was 90 months. A positive-DAT was found in 6 to 7% of essential thrombocythemia (ET) and polycythemia vera (PV) patients, 60% of primary myelofibrosis (PMF) patients and 50% of myelodysplasia/myeloproliferation (MDS/MPN) patients with or without anemia. Autoimmune manifestations were present in 13% of patients with PV and 50% of those with MDS/MPN features. Overall, 25% of patients had autoimmune phenomena including the 15% with positive-DAT. Conclusion: In patients with JAK2V617F mutation, those with PMF and MDS/MPN subtypes are most likely to display a positive-DAT results and autoimmune manifestations (≥ 50%). Patients with PV and ET are less likely to exhibit autoimmune manifestations (≤ 10%). No correlation with the occurrence of thrombosis was seen.

Abstract 14082: Evans Syndrome Post Transcatheter Aortic Valve Replacement: A Rare Presentation

Description of Case: Evans Syndrome is a rare hematologic condition. Here we present a patient who developed Evans Syndrome post TAVR. A 63-year-old male with history of HFrEF and aortic stenosis presented with 2-week history of worsening shortness of breath and bilateral lower extremity swelling. He was found to be in cardiogenic shock. TTE showed (LFLG) aortic stenosis (AS). Due to concomitant cardiogenic shock and tachyarrhythmias, we were unable to perform dobutamine stress echo. A cardiac CT was performed which revealed an aortic valve calcium score of 2761 (Figure 1). The diagnosis of severe AS was confirmed, and patient underwent TAVR. Postprocedural TTE showed significant improvement in EF. Patient’s complete blood count on admission was remarkable for Hgb of 12.5 g/dL and PLT of 148 k/mm 3 . Both Hgb and PLT began to drop significantly following TAVR. We ruled out vascular access site bleeding, mechanical complication from paravalvular leak, nutritional deficiencies, disseminated intravascular coagulation, heparin-induced thrombocytopenia, thrombotic thrombocytopenic purpura, myelodysplastic syndrome, HIV, hepatitis C. Autoimmune hemolytic anemia was identified given elevated lactate dehydrogenase, low haptoglobin, and positive IgG direct antiglobulin test. We started steroids and treat the case as Evans syndrome. PLT count improved from 67 to 117 k/mm 3 within 2 days of steroids initiation. The bone marrow biopsy was deferred to outpatient follow up given the response to steroids. Patient was discharged on oral prednisone. Three-month follow up showed Hgb and PLT with normal limits. Discussion: Anemia and thrombocytopenia are common complications post TAVR. Both anemia and thrombocytopenia are suggested to be excellent markers for clinical outcomes, morbidity and mortality after TAVR. It is crucial to keep a broad differential for post TAVR anemia and thrombocytopenia. Less common causes should be evaluated and addressed to improve prognosis.

Favorable outcome without corticosteroids during post-artesunate delayed hemolysis with positive direct antiglobulin test in severe imported Plasmodium falciparum malaria, France

Objectives: Positive direct antiglobulin tests (DATs) have been reported in cases of post-artesunate delayed hemolysis (PADH), but the causal role of auto-immune hemolysis remains unclear. We aimed to analyze a cohort of patients with PADH and DAT during severe malaria.Methods: We describe PADH and DAT results in a 7-year multi-center retrospective cohort of patients receiving artesunate for severe imported malaria.Results: Of 337 patients treated with artesunate, 46 (13.6%) had at least one DAT result within 30 days of treatment initiation, and 25/46 (54.3%) had at least one positive DAT. Among 40 patients with available data, 17 (42.5%) experienced PADH. Patient characteristics were similar for patients with a positive or negative DAT, and DAT positivity was not associated with PADH occurrence (P = 0.36). Among patients, 5/13 (38.5%) with a positive DAT after day 7 experienced PADH, compared to 10/13 (76.9%) of those with a negative DAT after day 7 (P = 0.11). Overall, 41% of patients required blood transfusions, and outcome was favorable without corticosteroids, even in cases of PADH.Conclusions: DAT does not appear to be a marker of PADH, but rather an indirect marker of an immune-mediated mechanism. DAT positivity should not lead to the administration of systemic corticosteroids during PADH.

Red blood cell alloimmunization in myelodysplastic syndromes: Associations with sex, DAT-positivity, and increased transfusion needs.

Many patients with myelodysplastic syndromes (MDS) need repeated red blood cell transfusions which entails a risk of immunization and antibody formation. Associations between alloantibodies, autoantibodies and increased transfusion requirements have been reported, but their relationship remains unclear. In this study, we analyzed factors potentially associated with red blood cell alloimmunization, as well as changes in transfusion intensity and post-transfusion hemoglobin increments. In a retrospective cohort study, we linked Swedish MDS patients diagnosed between 2003 and 2017 to transfusion and immunohematology data. Potentially associated factors were analyzed using Cox proportional hazards regression. The transfusion rate after detected alloimmunization was analyzed using a fixed effects Poisson regression. Post-transfusion hemoglobin increments before and after alloimmunization were compared using a mixed effects regression. Alloantibodies following MDS diagnosis were detected in 50 out of 429 patients (11.7%). Female sex and a positive direct antiglobulin test (DAT) were independently associated with alloimmunization, with hazard ratios of 2.02 (95% confidence interval [CI] 1.08-3.78) and 9.72 (95% CI, 5.31-17.74), respectively. The transfusion rate following alloimmunization was increased with an incidence rate ratio of 1.33 (95% CI, 0.98-1.80) and the post-transfusion hemoglobin increment after alloimmunization was 1.40 g/L (95% CI, 0.52-2.28) lower per red blood cell unit (p = .002) compared to before alloimmunization, in multivariable analyses. Alloimmunization against blood group antigens was associated with sex, DAT-positivity, increased transfusion needs, and lower post-transfusion hemoglobin increments. These findings warrant further investigation to evaluate the clinical significance of up-front typing and prophylactic antigen matching in patients with MDS.

Effects of prophylactic red blood cell (RBC) transfusion with extended antigen matching on alloimmunization in patients with Sickle Cell Disease (SCD)

BackgroundRBC alloimmunization remains a significant problem for many patients with SCD. To reduce alloimmunization some strategies have been implemented to provide limited or extended antigen matched RBC transfusions to patients with SCD who need chronic transfusion support. The aim of this study was to evaluate the effects of prophylactic RBC transfusion with extended antigen matching on alloimmunization in patients with SCD. MethodsThis is a 20-year retrospective study of patients with SCD transfused with RBCS that were prospectively matched for D, C, c, E, e, K, Fya/Fyb, Jka/Jkb and S antigens. Our study included 95 patients, and none had antibodies documented before their first transfusion. Patients and donors were phenotyped and molecular typing was performed in all patients who had recent transfusions or a positive direct antiglobulin test to predict their antigen profile. Unexpected antibodies to the Rh system, meaning anti-Rh antibodies in patients whose serologic phenotype was Rh positive, were investigated by molecular genotyping for RH variant alleles. ResultsDuring this study-period, 12 (12.6%) were alloimmunized and 83 (87.4%) were not. Among the 12 patients who alloimmunized, 7 (58.3%) developed antibodies to Rh antigens and 5 (41.7%) produced antibodies to low prevalence antigens. All patients who developed Rh antibodies had RH variant alleles. Autoantibodies were found in 16 (16.8%) transfused patients. ConclusionSCD patients benefit from receiving prophylactic RBC transfusions with extended antigen matching, as demonstrated by the reduction on the rates of alloimmunization and the lack of antibodies to K, FY, JK and S antigens, however, this strategy does not avoid alloimmunization to Rh and low-prevalence antigens.

The Severity of Direct Antiglobulin Test Negative ABO Hemolytic Disease of Newborn: A Retrospective Analysis at a Tertiary Children’s Hospital

This study aimed to evaluate the severity of ABO hemolytic disease of newborn (ABO-HDN) with negative direct antiglobulin test (DAT), which was identified by elution test. We retrospectively reviewed the clinical records of all neonates admitted with the diagnosis of neonatal hyperbilirubinemia requiring phototherapy or exchange transfusion. Neonates were divided into four groups according to their immunohematology test results. Then their essential laboratory results, magnetic resonance image (MRI), brainstem auditory evoked potential (BAEP) findings, and rate of exchange transfusion were compared between different groups. We found that neonates in ABO-HDN with negative DAT group developed jaundice faster and anaemia more severely than those in the non-HDN group. Although they might get less severe anaemia than neonates in ABO-HDN with positive DAT group and the Rh-HDN group, neonates in ABO HDN with negative DAT group might develop jaundice as quickly as the latter two groups. As to MRI and BAEP findings, there were no significant differences among the four groups. The rate of exchange transfusion in ABO-HDN with negative DAT group was higher than that in the non-HDN group but lower than that in ABO-HDN with positive DAT group, though without statistical significance. It suggested that in the presence of clinical suspicion of ABO-HDN with negative DAT result, the elution test should be added to rule out or confirm the diagnosis to help prevent the morbidity from hyperbilirubinemia.

A 71-year-old male with a life-threatening recurrence of hemolytic anemia, thrombocytopenia, and acute kidney injury after pembrolizumab therapy: a case report

BackgroundImmune checkpoint inhibitors (ICIs) have revolutionized cancer treatment. However, their use has been restricted in patients with preexisting autoimmune diseases due to concerns about increased risk of immune-related adverse events (irAEs).Case presentationWe present a case of a patient with stage IV lung adenocarcinoma and a history of complement-mediated autoimmune hemolytic anemia in remission. After receiving a single dose of pembrolizumab, the patient experienced life-threatening recurrent hemolytic anemia, de novo thrombocytopenia, diarrhea, myocarditis, and acute kidney injury. Laboratory tests confirmed the diagnosis of Evan's syndrome, with positive PAIgG and direct antiglobulin test. Treatment with intravenous methylprednisolone at a dose of 2 mg/kg resulted in a favorable response, with resolution of symptoms and rapid recovery of kidney function. The probable cause of pre-renal hypoperfusion (evidenced by a BUN-to-creatinine ratio of 48.1) leading to acute tubular injury was attributed to pembrolizumab-induced diarrhea.ConclusionsThis case illustrates a life-threatening recurrence of complement-mediated autoimmune hemolytic anemia induced by ICIs. Clinicians should carefully consider the expected efficacy and potential toxicity before initiating ICIs therapy in patients with preexisting autoimmune diseases. Additionally, the occurrence of acute kidney injury during ICIs therapy adds complexity and requires careful differential diagnosis.

Positive direct antiglobulin tests in cancer patients on immune checkpoint inhibitors: A case series from India.

Tumour cells activate immune checkpoints such as programmed death receptor-1 (PD-1) and cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) signalling pathways to inhibit T lymphocyte activation and thus escape from immune surveillance. Immune checkpoint inhibitors (ICPis) reactivate T lymphocytes to recognize cancer cells by blocking CTLA-4 or PD-1. Autoimmune haemolytic anaemia is a rare, but often severe, complication of ICPis. Therefore, we performed a retrospective clinical case review, including serologic, haematology, and biochemistry laboratory results, of three patients who developed autoantibodies to erythrocytes following treatment with pembrolizumab, an anti-PD-1 inhibitor. Serologic testing of blood samples from these patients showed their red cells were positive for direct antiglobulin test (DAT+for IgG in two cases and IgG with C3d in one case). Antibody detection test was negative. No patient had clinical and laboratory features of haemolysis. There were no additional immune-related adverse events. IgG antibodies coating red cells were neither IgG1 nor IgG3 in class and elution was found negative in all. In conclusion, immunohaematology laboratories should be aware of the possibility of erythroid autoantibodies and their nature in cancer patients receiving ICPis. The result of a positive DAT should be interpreted carefully in these patients to exclude other possible causes of anaemia.

Risk factors for readmission for hyperbilirubinemia in neonates with ABO hemolytic disease: a single-center retrospective cohort study

Objective ABO hemolytic disease of the newborn (ABO-HDN) is a major risk factor for severe hyperbilirubinemia, a common readmission reason for newborns. In this study, we aimed to assess the risk factors for readmission associated with hyperbilirubinemia in neonates with ABO-HDN. Methods A retrospective cohort study was conducted including newborns with gestational age ≥35 weeks and ABO-HDN in 2018. Among 291 newborns, 36 were readmitted for hyperbilirubinemia and defined as the readmission group. The remaining 255 cases were used as a control group. We then performed between-group comparisons of clinical conditions associated with hyperbilirubinemia. Logistic regression was used to select risk predictors of readmission associated with hyperbilirubinemia due to ABO-HDN. Results Baseline characteristics were similar between both groups (p > .05, respectively). However, total serum bilirubin (TSB) before initiating phototherapy was significantly higher in the readmission group when compared with that in the control group at 0–24 h, 24–48 h, and 48–72 h (183.70 µmol/L [interquartile range (IQR) 161.18–196.48] vs. 150.35 µmol/L [IQR 131.73–175.38], p = .005; 229.90 µmol/L [IQR 212.45–284.30] vs. 212.50 µmol/L [IQR 197.85–230.28], p = .026; 268.10 µmol/L [IQR 257.70–279.05] vs. 249.50 µmol/L [IQR 236.80–268.70], p = .045, respectively). The age of initiation of phototherapy in the readmission group was significantly lower than that in control group (30.0 h [IQR 18.0–49.00] vs. 42.0 h [IQR 23.0–61.0], p = .012). The rate of rebound hyperbilirubinemia after the first phototherapy treatment was significantly higher in the readmission group compared to that in the control group (9 [25%] vs. 13 [5.1%], p = .000), and the rate of positive direct antiglobulin testing was significantly higher than that in control group (17 [47.2%] vs. 74 [29.0%], p = .027). Logistic regression analysis showed that the age of initiation of photography, TSB level before the first phototherapy, and rebound hyperbilirubinemia after first phototherapy were independent risk factors for readmission in newborns with hyperbilirubinemia associated with ABO-HDN. Conclusions Earlier age of phototherapy initiation, higher TSB levels at the time of initiating phototherapy and rebound hyperbilirubinemia after the first phototherapy treatment may increase the risk of readmission for hyperbilirubinemia in neonates with ABO-HDN. These factors should be considered in discharge planning and follow-up for newborns with ABO-HDN associated hyperbilirubinemia.

The Indirect Antiglobulin (Coombs') Test Is Specific but Less Sensitive Than the Direct Antiglobulin Test for Detecting Anti-Erythrocytic Autoantibodies and Thereby Immune-Mediated Hemolytic Anemia in Dogs.

The immunodiagnostic assessment of dogs suspected of having immune-mediated hemolytic anemia (IMHA) is based on persistent autoagglutination of erythrocytes (after three saline washes), marked spherocytosis, and a positive direct antiglobulin (Coombs') test (DAT). However, the value of using the indirect antiglobulin test (IAT) for the detection of anti-erythrocytic autoantibodies in serum from dogs suspected of having IMHA is unclear. To evaluate the IAT, leftover serum samples from a large cohort of 94 dogs suspected of having IMHA and for which DAT results were known were incubated with DAT- erythrocytes, and five IAT techniques were performed (in part with different reagents and temperatures): microtiter plate (MICRO), microcapillary, laboratory gel column, gel minitube kit (GEL KIT), and immunochromatographic strip kit. Two IAT techniques (MICRO at 37 °C and GEL KIT with rabbit anti-dog polyvalent reagent) detected autoantibodies against erythrocytes in serum from 53% and 57% of DAT+ dogs, respectively, while other IATs performed less well. Moreover, while the analytic specificity of the IAT methods compared to the DAT ranged from 96-100%, the sensitivity range was only 9-57%. Thus, we still recommend DAT for diagnosis and monitoring of IMHA in dogs but conclude that a positive IAT result may aid diagnostically when serum is available, but fresh red blood cells are not.

Does strengths of a positive direct antiglobulin test predicts the need for phototherapy and duration of phototherapy? – a single center, retrospective study

Background Use of Direct Antiglobulin test (DAT) in management of neonatal hyperbilirubinemia is conflicting. Objective whether strength of positive DAT predicts the need for phototherapy, duration of phototherapy and need for major interventions. Methods We retrospectively collected data on all DAT positive neonates with birth gestational age ≥32 weeks over six years (2014–2019). Data regarding blood group, DAT and clinical details were obtained from a hospital database. We also collected data on serial hemoglobin and other relevant laboratory parameters. We also collected data on infants receiving major interventions such as exchange transfusion, in-utero transfusion, immunoglobulins, and postnatal transfusion for the duration of the study period. All of these infants were electronically followed up for a period of 6 weeks. This study was approved by institutional audit authority. All the statistics were performed using SPSS software. Results Out of 1285 DAT tests performed, only 91 infants were positive (7%), and 78 DAT positive infants were available for analysis. There were 54 infants with DAT (1+), 15 infants with DAT (2+), 7 infants with DAT (3+) and 2 infants with DAT (4+). There was no significant statistical difference in terms of need for phototherapy, duration of phototherapy, need for major interventions and hemoglobin levels at different time points between the groups (DAT 1+ Vs DAT ≥2+; DAT ≤2+ Vs DAT >2). A Total of 10 infants received major intervention, with one infant receiving all three interventions (DAT 3+ with significant maternal antibodies), 2 additional infants (both DAT1+) received exchange transfusion, 6 additional infants received immunoglobulin (2 infants: DAT 2+; 4 infants: DAT 1+) and one additional infant (DAT 1+) with significant maternal antibodies received a postnatal transfusion. Conclusion Strength of a DAT did not predict the need for phototherapy, duration of phototherapy, and the need for major hemolysis related intervention in the first 6 weeks of life.

Neonatal hemolytic disease: How should we use indirect and direct antiglobulin tests?

In newborns with hemolysis, the direct antiglobulin test (DAT) and indirect antiglobulin test (IAT) play a key role in demonstrating the presence of an immune cause. We aimed to emphasize the importance of IAT in mothers of DAT-positive babies. DAT was performed with forward blood grouping on cord blood in term babies who were born between September 2020 and September 2022. IAT was performed in the mothers of the babies who were found to have a positive DAT and antibody identification was performed in the mothers who were found to have a positive IAT. Specific antibodies detected and identified were associated with the clinical course. The study included 2769 babies and their mothers. The prevalence of DAT positivity was found to be 3.3% (87 of 2661). In DAT-positive babies, the rate of ABO incompatibility was 45.9%, the rate of RhD incompatibility was 5.7% and the rate of RhD and ABO incompatibility in association was 10.3%. The rate of subgroup incompatibility and other red blood cell antibodies was 18.3%. Phototherapy was applied because of indirect hyperbilirubinemia in 16.6% of the DAT-negative babies and in 51.5% of the DAT-positive babies. The need for phototherapy was significantly higher in DAT-positive infants (p<0.01). Severe hemolytic disease of the newborn, bilirubin level, duration of phototherapy and use of intravenous immunoglobulin were found to be significantly higher in the babies whose mothers were IAT positive compared with the babies whose mothers were IAT negative (p<0.01). IAT should be performed on all pregnant women. When screening with IAT is not performed during pregnancy, performing DAT in the baby plays a key role. We showed that the clinical course was more severe when mothers of DAT-positive babies were IAT positive.

Significance of immunohematologic testing in mother and newborn ABO incompatibility.

The aim of this study was to define risk factors for jaundice and anemia in newborns with a positive direct antiglobulin test (DAT) and/or with an incompatible crossmatch due to ABO incompatibility between mother and newborn. ABO incompatibility has become a more significant cause of hemolytic disease of the fetus and newborn since the introduction of effective anti-D prophylaxis. The condition is common and, if clinically significant at all, causes only mild jaundice, which can be treated with phototherapy (PT). However, rare and serious presentations, requiring transfusion therapy, have been noted. Clinical, laboratory, and immunohematologic data were collected retrospectively from medical records of ABO-incompatible newborns and their mothers over a 5-year period (2016-2020) from University Hospital Centre Zagreb. Two groups of newborns were compared: those who needed medical intervention because of hyperbilirubinemia or anemia and those who did not. Within the group of newborns requiring intervention, we also compared those with A and B blood groups. Over the 5-year period, 72 of 184 (39%) newborns required treatment. The treatment was PT in 71 (38%) newborns and erythrocyte transfusion in 2 (1%). In 112 (61%) newborns, ABO incompatibility was an accidental finding while performing blood group typing; these newborns did not require any therapy. In conclusion, we found a statistical, but not clinically significant, difference between the groups of treated and untreated newborns, related to the mode of delivery and DAT positivity within hours of delivery. There were no statistically significant differences in characteristics between the groups of treated newborns, except for two newborns with blood group A who received erythrocyte transfusions.