Incidence and risk factors for intravenous immunoglobulin-related hemolysis: A systematic review of clinical trial and real-world populations

The clinical value of dynamic monitoring of complete blood count in predicting immunoglobulin resistance in Chinese children with Kawasaki disease

To examine changes in peripheral blood complete blood count (CBC) parameters during acute Kawasaki disease(KD), compare immunoglobulin(IVIG)-sensitive and IVIG-resistant groups, and develop an IVIG resistance model. A retrospective review of clinical and lab data from 282 KD patients (2014-2024) was conducted. CBC parameters were collected at initial, pre-IVIG, and post-IVIG stages. The rank-sum test assessed parameter differences over time. Patients were categorized into IVIG-resistant (n = 29) and IVIG-sensitive (n = 253) groups. Univariate and multivariate logistic regression analyses identified IVIG resistance risk factors, resulting in four predictive models (A, B, C, and D) based on blood changes and clinical experience. The models' effectiveness was evaluated using receiver operating characteristic (ROC) curves, the Hosmer-Lemeshow test, and decision curve analysis, with the bootstrap(BS) method confirming performance. Significant differences were found in post-IVIG blood parameters, including white blood cell count (WBC), neutrophils, lymphocytes, eosinophils, hemoglobin, platelets, neutrophil to lymphocyte ratio (NLR), platelet to lymphocyte ratio (PLR), and mean platelet volume to lymphocyte ratio (MPVLR), compared to pre-IVIG and initial CBC (P < 0.05). In IVIG-resistant patients, NLR, PLR, MPVLR, neutrophil percentage were higher, while lymphocyte percentage was lower than in IVIG-sensitive patients (P < 0.05). The resistant group also showed smaller changes in neutrophil percentages (△N) and lymphocyte percentages (△L). Area under the curve (AUC) values for BS-ROC curves were as follows: model A: 0.758 (95% CI: 0.636-0.878), model B: 0.917 (95% CI: 0.852-0.982), model C: 0.949 (95% CI: 0.909-0.978), and model D (NLR post-IVIG administration combined with △L): 0.910 (95% CI: 0.857-0.963). Hosmer-Lemeshow test P values for all four models were > 0.05. DCA indicated clinical value for all models, especially model C. Blood routine parameters in children with KD vary over time, and IVIG administration alters these parameters. We developed and validated four prediction models for IVIG resistance in KD patients using blood routine data. This indicates that ongoing monitoring of these parameters can predict IVIG resistance and enhance patient outcomes.

Practice of ABO antibody titration in a transplant center: From tube method to manual gel column testing to automated column agglutination technology

BACKGROUND AND OBJECTIVES

High-quality ABO antibody titre testing is required for ABO-incompatible haematopoietic stem cell transplantation and kidney transplantation. To assess the feasibility of automated ABO titration as an alternative to manual and semi-automatic titration during the peri-transplant period, a comparative study was conducted internally in a transfusion medicine laboratory.

MATERIALS AND METHODS

This study was performed in two stages. Firstly, the differences in anti-A/B detecting using conventional tube test (CTT) and manual column agglutination technology (CAT) were compared in group O pregnant women. Then, manual and automated CAT were applied to simultaneously detect ABO antibody levels in non-AB-group adult haematological oncology patients.

RESULTS

In the first stage, four groups of 192 comparable results were generated from 48 subjects, which showed a high correlation between CTT and manual CAT (p < 0.001). However, the detection sensitivity of the latter was at least 1 fold higher dilution than that of the former. Fifty-six patients were tested in the second stage by simultaneous manual and automated CAT, and the paired titers differed within an acceptable range (±1 fold dilution). However, the concordance was slightly higher in group IgM (85.4%) than in group IgG (80.5%). Blood group specificity of ABO titers was also observed in this population, and no association between titers and other factors was found.

CONCLUSION

Automated CAT standardises ABO titre testing and saves labor costs, although manual review of weak positive reactions is still necessary. Due to the blood group specificity of ABO antibodies, special attention should be paid to the quality control and clinical relevance of titre testing for group O recipients in ABO-mismatched transplantation.

A review of intravenous immunoglobulin in the treatment of neuroimmune conditions, acute COVID-19 infection, and post-acute sequelae of COVID-19 Syndrome

Intravenous immunoglobulin (IVIG) is an immunomodulatory therapy that has been studied in several neuroimmune conditions, such as Guillain-Barré Syndrome, chronic inflammatory demyelinating polyneuropathy, multifocal motor neuropathy, and multiple sclerosis. It has also been proposed as a potential treatment option for acute COVID-19 infection and post-acute sequelae of SARS-CoV-2 infection (PASC). IVIG is thought to function by providing the recipient with a pool of antibodies, which can, in turn, modulate immune responses through multiple mechanisms including neutralization of cytokines and autoantibodies, saturation of neonatal fragment crystallizable receptors, inhibition of complement activation, and regulation of T and B cell mediated inflammation. In acute COVID-19, studies have shown that early administration of IVIG and plasmapheresis in severe cases can reduce the need for mechanical ventilation, shorten ICU and hospital stays, and lower mortality. Similarly, in PASC, while research is still in early stages, IVIG has been shown to alleviate persistent symptoms in small patient cohorts. Furthermore, IVIG has shown benefits in another condition which has symptomatic overlap with PASC, myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), though studies have yielded mixed results. It is important to note that IVIG can be associated with several potential adverse effects, such as anaphylaxis, headaches, thrombosis, liver enzyme elevations and renal complications. In addition, the high cost of IVIG can be a deterrent for payers and patients. This review provides a comprehensive update on the use of IVIG in multiple neuroimmune conditions, ME/CFS, acute COVID-19, and PASC, as well as covers its history, production, pricing, and mechanisms of action. We also identify key areas of future research, including the need to optimize the use of Ig product dosing, timing, and patient selection across conditions, particularly in the context of COVID-19 and PASC.

Transfusion support and pre-transfusion testing in autoimmune haemolytic anaemia

Autoimmune haemolytic anaemia (AIHA) is characterized by an increased destruction of red blood cells due to immune dysfunction and auto-antibody production. Clinical manifestations are mainly related to anaemia, which can become life-threatening in case of acute haemolysis. Aiming at counterbalancing severe anaemia, supportive treatments for these patients frequently include transfusions. Unfortunately, free serum auto-antibodies greatly interfere in pre-transfusion testing, and the identification of compatible red blood cell units for AIHA patients can be challenging or even impossible. Problems faced in pre-transfusion testing often lead to delay or abandonment of transfusions for AIHA patients. In this review, we discuss publications concerning global transfusion management in AIHA, with a focus on pre-transfusion testing, and practical clues to manage the selection of transfusion units for these patients. Depending on the degree of transfusion emergency, we propose an algorithm for the selection and laboratory testing of units to be transfused to AIHA patients.

Rational use of immunoglobulins (IVIgs and SCIgs) in secondary antibody deficiencies

Immunoglobulins for intravenous use (IVIgs) and subcutaneous use (SCIgs) can prevent recurrent and severe infections in patients with secondary antibody deficiencies that are frequently linked to haematological/oncological malignancies as well as other clinical conditions and their respective treatments. Even so, as IVIgs and SCIgs are costly and their supply is limited, their clinical use must be optimised. The aim of this position paper is to provide structured practical guidance on the optimal use of IVIgs and SCIgs in secondary antibody deficiencies, particularly in haematological and oncological practice. The authors agree that the occurrence of severe infections is a prerequisite for the use of IVIgs. Serum IgG levels in general as well as IgG subclass levels can be additional indicators of whether a patient could benefit from IVIgs. Responsiveness to vaccines can help to identify immunodeficiency. Patients with chronic lymphocytic leukaemia or multiple myeloma who are receiving respective treatment, especially B-cell depletion therapy, but also some patients with autoimmune diseases are prone to antibody deficiencies and need IVIgs. For the optimal use of IVIgs and to maximise their potential benefit, the indication must be individually assessed for each patient. As a primary treatment goal, the authors define a sufficient prophylaxis of severe infections, which can be supported by normalising IgG levels. If the initiated treatment is insufficient or linked to intolerable adverse reactions, switching the product within the class of IVIgs or changing to a different batch of the same product can be considered. Pausing treatment can also be considered if there are no infections, which happens more frequently in summer, but treatment needs to be resumed once infections return. These structured recommendations for IVIg treatment in patients with secondary antibody deficiency may provide guidance for clinical practice and therefore help to allocate IVIgs to those who will benefit the most, without overusing valuable resources.

Isohemagglutinin titration in pooled and apheresis platelets

BACKGROUND

Platelet inventory constraints necessitate ABO-incompatible platelet transfusion. Many minimize the hemolytic impact by confirming low titre (LT) donor isohemagglutinins. This process is costly. Pathogen-reduced platelets (PRP) in platelet additive solutions (PAS) will dilute plasma and decrease high-titre isohemagglutinins (HT). We determined the proportion of HT platelets and incompatible transfusions for units suspended in plasma to reassess the need for titres following introduction of PRP/PAS.

STUDY DESIGN AND METHODS

Our titre method is manual tube (1:50) dilution of platelet supernatant from apheresis or whole blood derived buffy coat pools suspended in plasma, tested with A1/B red cells. Testing included 49,058 pooled and 11,738 apheresis platelets over 4 years. The HT proportion, rate of out-of-group transfusions, and hemolytic reactions were determined. The impact of PAS dilution was estimated.

RESULTS

Totally 60,796 platelet units were tested. Group O pooled and group B apheresis platelets had HT in 6.6% and 5.7%, respectively. Group A pooled and apheresis platelets included 2% with HT. Approximately 25% of platelets transfused were ABO-incompatible and no hemolytic reactions were reported. Based on the proportions of PAS-E and plasma for PRP platelets, plasma from each donor comprises 11 mL (6% of total volume) vs 20-257 mL in untreated pools. PAS-E will replace and dilute residual plasma by at least 50%.

DISCUSSION

Rare platelet pools may demonstrate HT. PRP platelets with PAS will reduce titres and may abrogate the need for titration. A strategy of group specific transfusion or transfusion of group A PRP platelet transfusions may be a safe alternative.

Prevention of potential delayed hemolytic transfusion reaction in two sickle cell patients using intravenous immunoglobulins and steroids before and after red blood cell exchange with antigen positive units and review literature

Emergent Red Blood Cell (RBC) exchange is indicated in sickle cell disease (SCD) patients with severe acute chest syndrome. However, fully matched RBC units may not be available for patients with multiple RBC antibodies. Intravenous immunoglobulin (IVIG) and steroids were reported for preventing potential delayed hemolytic transfusion reaction (HTR) in simple transfusion of antigen-positive RBCs. We investigated the efficacy and safety of IVIG and steroids in two SCD patients presented with acute chest syndrome receiving RBC exchange with multiple incompatible units. The first patient had multiple historical alloantibodies, including anti-Jsb, although none of them were reactive. IVIG (1 g/kg) was given before and after RBC exchange with methylprednisolone (500 mg IV) one hour before exchange. Her sickle hemoglobin (HbS) was reduced from 89.4% to 17.4% after the exchange with five Jsb-positive units. The patient improved clinically without acute or delayed hemolysis. The second patient had reactive anti-Jsb on two different admissions 18 months apart. Only one of the sixteen units used in the exchanges was Jsb negative. He received the same IVIG regimen during both admissions but 100 mg IV hydrocortisone instead of methylprednisolone. His HbS was reduced from 63.4% to 22.4% after the first exchange. Significant clinical improvements were achieved after both exchanges. No delayed HTR was observed. Our experience of these two patients suggested that IVIG and steroids may be used in preventing potential delayed HTR in some SCD patients with rare antibodies receiving large amounts of antigen-positive RBC products.

A retrospective analysis of haemolytic reactions to intravenous immunoglobulin using data from the Transfusion-Transmitted Injuries Surveillance System (Ontario)

BACKGROUND AND OBJECTIVES

Haemolysis can occur following intravenous immunoglobulin (IVIG) infusion. Haemovigilance data were analysed using a novel approach for including two control groups with no haemolysis to IVIG. Objectives included a summary of all reactions to IVIG, rate estimates and analysis of haemolytic reactions including risk factors.

MATERIALS AND METHODS

Canadian haemovigilance data from Ontario (2013-2021), IVIG distribution and transfusion data from the blood supplier, and data from a large local transfusion registry were used. An 'other-reactions' control group included patients with IVIG reactions that were not haemolytic, and registry patients with no-reaction were the 'no-reaction controls'. Descriptive analysis and two logistic regression models for the different control groups were performed.

RESULTS

One thousand one hundred and seventy reactions were included. Most common were febrile non haemolytic (26.1%), minor allergic (24.5%) and IVIG headache (15.3%) followed by haemolytic 10.9% (128/1170). Haemolytic reaction rates decreased over time: rates since 2020 estimated between 1.5 and 2.9/1000 kg IVIG used. The regression model for other-reaction controls identified two risk factors for haemolysis: non-O blood group recipients compared with group O recipients (p value = 0.0106) and IVIG dose per 10 g increase (OR 1.359; 95% CI 1.225-1.506). The model using no-reaction controls gave similar results and also showed no pre-medication was associated with a higher risk of haemolysis (OR 29.084; 95% CI 1.989-425.312).

CONCLUSION

The frequency of haemolytic reactions has decreased over time. We confirmed non-O blood group recipients and IVIG dose as risk factors for haemolysis and raise the hypothesis that no pre-medication may increase the risk of haemolysis.

Biochemical Characterization of a New 10% IVIG Preparation [IgG Next Generation (BT595)/Yimmugo®] Obtained from a Manufacturing Process Preserving IgA/IgM Potential of Human Plasma

BACKGROUND AND OBJECTIVE

Human plasma is used for the generation of several life-saving drugs and contains valuable antibodies from the immunoglobulin classes IgG, IgM and IgA. Purified intravenous IgG solutions (IVIGs) form the majority of plasma-derived medicine to treat patients with various forms of immunodeficiencies. In conventional IVIG manufacturing processes, immunoglobulin classes IgM and IgA are often discarded as contaminants, but these antibody classes have been proven to be effective for the treatment of acute bacterial infections. Considering the increase in demand for human plasma-derived products and the ethical value of the raw material, a more resource-saving usage of human plasma is needed. Intensive research over the last decades showed that adverse reactions to IVIGs depend on the presence of thrombogenic factors, partially unfolded proteins, non-specific activation of the complement system, and blood group specific antibodies. Therefore, new IVIG preparations with reduced risks of adverse reactions are desirable.

METHOD

A new manufacturing process that yields two biologics was established and quality attributes of the new IVIG solution (Yimmugo®) obtained from this process are presented.

RESULTS

Here, we provide a biochemical characterization of Yimmugo®, a new 10% IVIG preparation. It is derived from human blood plasma by a combined manufacturing process, where IgM and IgA are retained for the production of a new biologic (trimodulin, currently under investigation in phase III clinical trials). Several improvements have been implemented in the manufacturing of Yimmugo® to reduce the risk of adverse reactions. Gentle and efficient mixing by vibration (called "vibromixing") during a process step where proteins are at risk to aggregate was implemented to potentially minimize protein damage. In addition, a dedicated process step for the removal of the complement system activator properdin was implemented, which resulted in very low anticomplementary activity levels. The absence of measurable thrombogenic activity in combination with a very high degree of functional monomeric antibodies predict excellent efficacy and tolerability.

CONCLUSION

Yimmugo® constitutes a new high quality IVIG preparation derived from a novel manufacturing process that takes advantage of the full therapeutic immunoglobulin potential of human plasma.

Intravenous Immunoglobulin-Associated Severe Hemolytic Anemia

Intravenous immunoglobulin (IVIG) is used to treat immunodeficiency conditions, neuro-immunological, infection-related, autoimmune, and inflammatory disorders and is typically well tolerated. A hematological adverse reaction such as hemolytic anemia and neutropenia is known to occur with IVIG, which is usually transient and subclinical. However, severe hemolytic anemia is known to occur in some cases. We present a case of a 66-year-old man who developed severe symptomatic hemolytic anemia after receiving IVIG for acute inflammatory demyelinating polyneuropathy (AIDP). The patient had known risk factors such as non-O blood group, high cumulative dose of IVIG, and underlying autoimmune condition, which would have put him at high risk for developing hemolytic anemia after IVIG. Therefore, it is prudent for clinicians to have increased awareness regarding the potential for severe hemolysis and closely monitor these patients with risk factors after treatments to identify this adverse reaction before more severe complications occur.