IVIG Products Research Articles

85 Incidence of Intravenous Immunoglobulins-related Adverse Events in Children

Abstract Background Intravenous immunoglobulins (IVIG) therapy is increasingly used in the treatment of various paediatric diseases. Data about frequency and underlying mechanisms of IVIG-related adverse events (IVIG-AEs) in children are limited. Objectives Objectives of this study were to document the incidence of IVIG-AEs in paediatric hospitalized patients and identify risk factors for IVIG-AEs. Design/Methods In this retrospective cohort study, we included patients aged < 18 years old who received IVIG therapy, for any indication, as inpatients at a Canadian paediatric tertiary care centre between 2016-2020. Patients and IVIG-perfusion characteristics were collected, as well as any AEs occurring during the perfusion or up to 10 days after. AEs were graded according to the Common Terminology Criteria for Adverse Events (CTCAE) version 5.0. Bivariate and multivariate logistic regressions were used to explore the associations between patients’ characteristics and the incidence of IVIG-AEs. Results We included 228 children in this study (mean age: 4 years), receiving 478 IVIG infusions. Indications for IVIG infusions included inflammatory (120/228, 52.6%), replacement (27/228, 11.8%) and auto-immune (81/228, 35.5%) disorders. A total of 211 IVIG-AEs were reported in 89/228 (39%) of patients, and 125/478 (26.2%) of infusions. Fever (65/478, 13.6%) was the most frequent AE, followed by headache (32/478, 6.7%) and tachycardia (31/478, 6.5%). Most IVIG-AEs were of mild (121/211, 57%) or moderate (66/211, 31%) severity, but 12% (24/211) were severe reactions (serious AEs or grade 3-4), and no fatal reactions (grade 5) were encountered. The highest proportion of IVIG-AEs occurred when administered for inflammatory conditions. Older age, dehydration, first infusion, higher IVIG dosage and concurrent allergies were significantly associated with IVIG-AEs, while treatment with a steroid was significantly associated with a reduced risk of AEs. Conclusion IVIG-AEs are frequent in children. While most of them are self-limited, more serious complications may occur. Adequate hydration, low concentrations of IVIG products and the administration of glucocorticoid prior to the infusion could minimize these AEs. Further research is necessary to prevent IVIG-AEs in high-risk children.

Immunoglobulin replacement products in current clinical use in the United States have poor neutralizing activity against SARS-CoV-2 Omicron strains

BackgroundIntravenous (IV) and subcutaneous (SC) Immunoglobulin G (IG) replacement products are in wide use in patients with primary antibody deficiency syndrome (PAD). There is limited data on the levels of anti-SARS-CoV-2 spike antibodies in IG products or their ability to neutralize emerging SARS-CoV-2 variants. There is lack of data on the impact of IG therapy on serum anti-SARS-CoV-2 spike or neutralizing antibody titers in PAD patients. MethodsWe measured anti-SARS-CoV-2 anti-spike antibody levels and neutralizing titers against historical (WA1/2020) and variant (B.1.617.2 [Delta] and BA.1 [Omicron]) strains in 158 lots of 6 different IG products, collected between August 2021 to April 2022 and manufactured between December 2019 to December 2021. IG products were compared to serum from 20 healthy donors vaccinated with 2 doses of Pfizer-BioNTech mRNA vaccine. Serum anti-spike antibody level and SARS-CoV-2 neutralization activity were measured in 27 PAD patients treated with the tested IG products. ResultsAnti-spike antibody titers started to increase in products manufactured in March 2021 and reached peak level, comparable to vaccinated healthy donors, in products manufactured in August 2021 (Fig. 1). The neutralization activity against WA1/2020 and Delta strains showed a similar pattern (Fig. 2). However, 95% of the tested products had no neutralization activity against Omicron. Until November 2021, IVIG products infused to patients in the study had anti-spike titers comparable to unvaccinated healthy donors (Fig. 3). Beginning in February 2022, IVIG products had anti-spike titers comparable to vaccinated healthy controls. Concurrent with a rise in anti-spike antibodies in IG products, PAD patients showed an increase in serum levels of anti-spike antibody and neutralizing activity against WA1/202 and Delta but not against Omicron variants. Testing of immunoglobulin replacement products neutralization activity against emerging variants BQ.1 and BQ.1.1 is underway. [Display omitted] [Display omitted] [Display omitted] ConclusionThe anti-SARS spike antibody and neutralization activity of IVIG products lags after the emergence of COVID-19 variants and currently have poor activity against Omicron strain. Because of the protracted manufacturing process, this is expected to be an ongoing challenge. As variants emerge, clinicians should consider additional means of protection for PAD patients such as vaccination, or prophylaxis with monoclonal antibodies.

Case Study: Successful transition to ASCENIV therapy with improved PROMs

ObjectiveThe purpose of this case study was to demonstrate the use of patient reported outcome measures (PROMs) to evaluate the effectiveness of therapy success and outcomes in a patient with primary immunodeficiency. BackgroundA 74-year-old Caucasian woman receives IVIg for the treatment of selective deficiency of immunoglobulin G [IgG] subclasses, ICD-10 D80.3. Past medical history includes chronic obstructive lung disease and hypothyroidism. After 4 months of receiving IVIg therapy in the home, the patient was transitioned to another IVIg product, ASCENIV, for the continued treatment of her condition. A multidisciplinary team conducted a retrospective review of her medical records from the start of care to current status. This included customized clinical assessments specific to primary immunodeficiency, wellness, and fatigue that were performed by the specialty infusion pharmacy and reported through the proprietary clinical outcomes program SoleMetrics®. The review also included progress notes, nursing assessments, and physician office visit notes.Table 1Soleo Health Wellness Scale.Score12345Energy LevelLots of energy and can do the things I want to doCan do most things, may need to rest at timesNormal level of energyFeel tired most of the time, spend a lot of time sitting and not engaging in activitiesStaying in bed most of the day due to fatigue, tired all dayMoodGood mood most of the timeFeel even temperedFeel blah some of the time, someimes feel crankyDepressed all of the time, irritable and annoyed with othersSleep PatternsGreat restful sleepGood sleepNo real problemsHave problems falling asleep or staying asleepInsomniaStress LevelVery relaxed, feel at peaceRelaxedNormal stress level and feeling calmSomewhat stressedVery stressedOverall Health and WellnessFeel greatFeel goodFeel OkayFeel badFeel bad all the time MethodsThe patient assessment and completion of select PROMs were performed prior to each dispense of the medication or at the time of a home infusion nursing visit. Wellness was assessed using the Soleo Health Wellness scale and an immunology disease-specific assessment. SummaryWellness was based on five questions related to overall wellness, mood, energy, sleep patterns, and stress. Scores were reported on a 1–5 scale, with one being the best. Other factors used were a subjective statement by the patient, “How are you feeling today,” emergency department and hospitalization records, reported infections, and medication changes. While on the previous IVIg regimen, the patient reported an average wellness score of 16.6 compared to an average of 13 while on ASCENIV. Additionally, while on ASCENIV the patient reported no infections, no emergency or hospital visits, and improvement in the ability to exercise and participate in family and social activities. ASCENIV is an Ig product manufactured to have high concentration of neutralizing antibodies to nine common respiratory viral infections, including respiratory syncytial virus. These characteristics may contribute to improved outcomes.Table 2Patient Wellness Scores.How would you describe your feeling of health and wellness?How would you describe your energy level and ability to participate in activities?How would you describe your mood?How would you describe your sleep patterns?How would you describe your stress level?Total score02/10/2022342341603/09/2022342351704/05/2022342451804/30/2022342441706/02/20223422415Change to ASCENIV06/30/2022322331307/08/2022322331308/06/2022322331309/24/2022322331310/01/2022322331311/01/20223223313 ConclusionsAfter 6 months of ASCENIV therapy, the patient showed significant improvement in her overall wellbeing and response to therapy.

Intravenous Immunoglobulin G (IVIG) Need Assessment Survey Toward Local Manufacturing of IVIG Using a Mini-Pool Plasma Fractionation Technique.

Immunoglobulin therapy has a crucial role in the treatment of primary and secondary immunodeficiencies as well as in a multitude of neurologic, hematologic, infectious, and autoimmune conditions. In the current study, a preliminary pilot scale needs assessment survey was conducted to examine the need for IVIG among patients in Addis Ababa, Ethiopia, and in so doing justify local manufacturing of IVIG products. The survey was performed by administering a structured questionnaire to private and government hospitals, a national blood bank, a regulatory body, and healthcare researchers working in academia and pharmaceutical companies. The questionnaire encompassed demographics and specific IVIG-related questions designed for each institution. Responses supplied in the study provide qualitative data. Our findings indicated that IVIG has been registered by the regulatory body for use in Ethiopia and there is a demand for the product in the country. The study also highlights that patients go as far as to clandestine markets to procure IVIG products at a cheaper price. To impede such illegal routes and make the product readily accessible, a small-scale and low-cost approach such as a mini-pool plasma fractionation technique could be implemented to locally purify and prepare IVIG using plasma collected through the national blood donation program.

SARS-CoV-2 Antibody Longitudinal Profile of Immune Globulin Preparations.

ABSTRACTIntroductionIntravenous immunoglobulin (IVIG) preparations, used for the treatment of antibody deficiencies, provide a glimpse of the general population’s antibody profile as each preparation is generated from a pool of thousands of donors. The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the virus responsible for the coronavirus disease 2019 (Covid-19) pandemic, and a vaccine for the prevention of Covid-19 was authorized for emergency use in December 2020. We completed a longitudinal analysis of SARS-CoV-2 antibody levels in commercial IVIG preparations.Materials and MethodsWe collected IVIG samples from our infusion clinic. IVIG product lot number, product name, and manufacturer information were recorded, with the date of preparation verified from the manufacturer. SARS-CoV-2 antibody titers as well as total immunoglobulin levels were measured using commercially available assays. The study received Institutional Review Board approval.ResultsWe found no SARS-CoV-2 antibodies in preparations generated on or before January 2020. Overall, SARS-CoV-2 antibody levels in IVIG preparations tended to increase with progressing preparation date. We observed a dramatic and continual rise of SARS-CoV-2 antibody levels in IVIG preparations made in the beginning after January 2021, coinciding with the peak in incidence of confirmed cases and availability of Covid-19 vaccines in the United States.ConclusionSARS-CoV-2 antibody levels in IVIG mirror case prevalence, and vaccination resulted in a far more rapid rate of rise in antibody levels. IVIG preparations or serum repositories can provide an accessible way to model a population’s evolving novel pathogen exposure, immunity, and vaccine response.

Incidence and Risk Factors for IVIG-Mediated Hemolysis

INTRODUCTIONHemolysis is a recognized complication of high-dose IVIG infusion, but as the majority of case reports are retrospective the actual incidence and risk factors for its occurrence are poorly understood. METHODS: Between November 2012 and October 2016, recipients of high-dose IVIG in Toronto (Canada) were prospectively monitored for hemolysis using a panel of investigations performed pre- and post-infusion and then 5-10 days later. Hemolysis was defined and graded as per the Canadian IVIG Hemolysis Pharmacovigilance Group, with both patient and product risk factors analyzed for correlation. RESULTS: After a preliminary analysis revealed a strong association with ABO group and dose, enrollment was restricted to patients with non-O blood group receiving doses ≥ 2 g/kg, adjusted for lean body mass. Within this cohort, 99 infusions to 78 patients completed the follow-up protocol, with hemolysis observed in 32 (32%) and 28 (36%) of cases, respectively. Hemolytic anemia of Grades 1, 2, 3 and 4 were observed in 10, 9, 2 and 7 patients, respectively, and an additional 4 patients hemolyzed but maintained a stable hemoglobin via reticulocytosis. Although the initial fall in hemoglobin was slightly larger in hemolytic than non-hemolytic reactions (-14.9 vs -11.1 g/L, p = 0.0091), in 84% of cases laboratory confirmation of hemolysis only manifested 5-10 days after the infusion. In contrast, while 88% of hemolyzers had a positive DAT immediately post-IVIG, this proportion had fallen to 38% by day 5-10. Amongst 49 infusions evaluated by day 5-10 monocyte monolayer assay, there was 69% correlation between the development of hemolysis and the presence of heightened phagocytic activity in patient monocytes, vs 43% correlation when testing was performed with monocytes from healthy controls. Further supporting a state of increased macrophage activation, the proportional increase in serum ferritin was greater in hemolyzers than non-hemolyzers (5.1-fold vs 2.1-fold, p = 0.033). Conversely, all positive DAT test results were for IgG only, with no evidence of complement deposition. In regards to predictors of hemolysis, univariate analysis identified a higher incidence with group AB than with other blood groups (90% vs 26%, p = 0.0001), in first-time compared to repeat recipients (50% vs 20%, p = 0.002), in patients not taking immunosuppressant medications (43% vs 23%, p = 0.0316), and in patients whose post-infusion DAT was 1+ or stronger as compared to weak or by eluate only (57% vs 19%, p = 0.0001). One of three manufacturers had a lower rate of hemolysis (0% vs 35%, p = 0.009) but was also more likely than the other two manufacturers to be given to patients on immunosuppressant medications (83% vs 24%, p=0.0001). No correlation was observed with year of treatment, patient age, sex, BMI, diagnosis, rate of infusion, steroid pre-medication, subjective symptoms or pre-infusion levels of CRP or IL1-RA. CONCLUSION: Amongst non-O blood group recipients of high-dose IVIG, hemolysis is common and appears to occur via delayed-onset phagocytosis by activated patient monocytes. The highest risk appears to be in patients with blood group AB, those who are receiving IVIG for the first time, who are not taking immunosuppressive medications, or who have a 1+ or stronger DAT immediately post-infusion. Whether specific IVIG products carry higher risk requires further study. DisclosuresLin:Pfizer: Other: advisory board; Pfizer: Honoraria; CSL Behring, Grifols: Other: unrestricted education grant; Novartis: Research Funding. Pavenski:Novartis: Honoraria; Ablynx: Other: participation in industry sponsored RCT; CSL Behring: Research Funding; Alexion Pharmaceuticals: Honoraria. Branch:CSL Behring (Bern): Research Funding; CSL Behring (Canada): Research Funding; Canadian Blood Services: Employment, Research Funding; ViroCarb Inc.: Other: Founder and stock holder.

Steady-State Serum IgG Trough Levels Are Adequate for Pharmacokinetic Assessment in Patients with Immunodeficiencies Receiving Subcutaneous Immune Globulin

Patients with primary immunodeficiency diseases often require lifelong immunoglobulin (IG) therapy. Most clinical trials investigating IG therapies characterize serum immunoglobulin G (IgG) pharmacokinetic (PK) profiles by serially assessing serum IgG levels. This retrospective analysis evaluated whether steady-state serum IgG trough level measurement alone is adequate for PK assessment. Based on individual patient serum IgG trough levels from two pivotal trials (phase 2/3 European [NCT01412385] and North American [NCT01218438]) of weekly 20% subcutaneous IG (SCIG; Cuvitru, Ig20Gly), trough level-predicted IgG AUC (AUCτ,tp) were calculated and compared with the reported AUC calculated from serum IgG concentration-time profiles (AUCτ). In both studies, mean AUCτ,tp values for Ig20Gly were essentially equivalent to AUCτ with point estimates of geometric mean ratio (GMR) of AUCτ,tp/AUCτ near 1.0 and 90% CIs within 0.80–1.25. In contrast, for IVIG, 10%, mean AUCτ,tp values were lower than AUCτ by >20%, (GMR [90% CI]: 0.74 [0.70–0.78] and 0.77 [0.73–0.81] for the two studies, respectively). Mean AUCτ,tp values calculated for 4 other SCIG products (based on mean IgG trough levels reported in the literature/labels) were also essentially equivalent to the reported AUCτ (differences <10% for all except HyQvia, a facilitated SCIG product), while differences for IVIG products were >20%. In conclusion, steady-state serum IgG levels following weekly SCIG remain stable, allowing for reliable prediction of AUC over the dosing interval using trough IgG levels. These findings indicate that measuring steady-state serum IgG trough levels alone may be adequate for PK assessment of weekly SCIG.

Novel Technology using polyacrylamide membranes for biological separations

PRIME technology is a novel preparative electrophoretic isolation method for the purification of biological proteins based on molecular size and charge. Molecular charge, generated by the choice of a suitable buffered pH system, is employed in combination with polyacrylamide hydrogel membranes of selected porosities to separate molecules. By using both size and charge as restrictive factors for purification, the PRIME method is able to isolate molecules with high yield and purity. In this paper, we discuss the use of PRIME technology in the purification of plasma proteins. In the present work, albumin at 93% purity was purified at high yield (98%). Using albumin-depleted plasma for further processing of immunoglobulins (IVIG), we were able to obtain an IVIG product yield as high as 92% and purity as high as 88%. Since PRIME does not use solvents or require sub-zero temperatures and is well-suited for plasma purification from modest plasma volumes, we propose the application of PRIME as a cost-effective and safe alternative to Cohn fractionation.

Unified infusion rates for 10% intravenous immunoglobulin

Although manufacturers recommend varying infusion rates for differing intravenous immunoglobulin products (IVIg), there may be improved efficiency and reduced potential for error with the application of a single infusion policy for all IVIg products. During the transition from a 6% to a 10% IVIg, we prospectively evaluated patient reported adverse reactions to IVIg with the 10% product (Intragam 10) given at a rate faster than recommended by the manufacturer. While there was a significant increase in the rate of immediate infusion reactions when compared with the previous IVIg preparation (Intragam P), there was no increase in the rate of reactions post infusion. The rate of reactions was within previously reported expectations for other IVIg products. All reactions were minor, requiring no or minimal intervention and few impacted significantly on the quality of life. Despite an active haemovigilance program, minor adverse reactions were generally not reported. Our results suggest that a fast single rate of IVIg infusion is safe, and may minimise patient attendance and hospital resources with acceptable safety. In implementing a strategy to increase IVIg infusion rates an active process to monitor safety is preferred over standard haemovigiliance or pharmacovigilance processes.

Characterization of isolated tau-reactive antibodies from the IVIG product, plasma of patients with Alzheimer's disease and cognitively normal individuals

The presence of natural tau-reactive antibodies was reported in human blood. In this study, we isolated and characterized natural tau-reactive antibodies occurring in IVIG product Flebogamma, plasma of patients with Alzheimer's disease (AD) and older cognitively normal persons (controls). Using blotting immunoassays and ELISA, we showed reactivity of antibodies obtained from IVIG and controls against a recombinant fragment of tau (155–421aa) and aggregates present in brains of AD patients. In contrast, antibodies isolated from plasma of AD patients reacted mainly with the recombinant full-length tau form and tau monomeric forms in brain tissue.

Efficacy, safety, and tolerability of Kedrion 10% IVIG in primary immunodeficiency

Background: Primary immunodeficiency involving defective antibody formation requires antibody replacement therapy with immunoglobulin products to prevent and reduce infections. Immunoglobulin for intravenous use (IVIG) is a processed blood product with limited availability, and the various marketed IVIG products may have different tolerability among patients. New IVIG products are therefore necessary to offer options to patients and to reduce the risk of a product shortage. Methods: Forty-five adult and pediatric patients with primary immunodeficiency, documented agammaglobulinemia or hypogammaglobulinemia, and antibody deficiency were enrolled in a prospective, multi-centre, open-label, single-arm historically controlled Phase III study to evaluate the safety, efficacy, and pharmacokinetics of a new 10% IVIG produced by Kedrion. Results: Forty-four patients completed the study while one withdrew consent. Over the 12-month study period, only 2 episodes of acute serious bacterial infections (both bacterial pneumonias) were recorded, for a mean annual event rate of 0.04 per subject, with an upper one-sided 99% confidence limit of 0.11. Values for all secondary efficacy endpoints were comparable with those in similar studies. The primary safety endpoint was met as the rate of infusions temporally associated (i.e., within 72 hours) with ≥1 adverse event was 16% (upper 95% confidence limit 20.4%). Pharmacokinetics were assessed in 31 patients and found to be comparable with those published for other IVIG products. Conclusion: Kedrion IVIG 10% is safe, efficacious, and well tolerated by patients with primary immunodeficiency. Statement of novelty: This report describes the safety, efficacy, and pharmacokinetics of a new IVIG preparation.

IVIG in autoimmune disease - Potential next generation biologics.

Polyclonal plasma-derived IgG is a mainstay therapeutic of immunodeficiency disorders as well as of various inflammatory autoimmune diseases. In immunodeficiency the primary function of IVIG/SCIG is to replace missing antibody specificities, consequently a diverse Fab-based repertoire is critical for efficacy. Attempts to capture the Ig repertoire and express it as a recombinant IVIG product are currently ongoing. Likewise correction of the defective genes by gene therapy has also been tried. However, both approaches are far from becoming mainstream treatments. In contrast, some of the most important effector mechanisms relevant in therapy of autoimmunity are based on the Fc-portion of IgG; they include scavenging of complement and blockade/modulation of IgG receptors (Fc gamma receptor [FcγR] or the neonatal Fc receptor [FcRn]). These effects might be achieved with appropriately formulated Fc-fragments instead of full-length IgG, as suggested by a pilot study with monomeric plasma-derived Fc in children with ITP and in Kawasaki disease in the 1990s. Since then it has been proposed that structured multimerization of Fc fragments might confer efficacy at much lower doses than with IVIG. Accordingly, various molecular strategies are currently being explored to achieve controlled Fc multimerization, e.g. by fusion of IgG1 Fc to the IgG2 hinge-region or to the IgM tail-piece. Safety considerations will be crucial in the evaluation of these new entities. In a different approach, mutant Fc fragments and monoclonal antibodies have been designed for blockade of the FcRn.

Selective Exclusion of High Titer Donor Plasma and Immunoadsorption Chromatography As Steps to Reduce Isoagglutinin Titers in IVIG

Hemolysis is a rare but potentially serious complication of high-dose IVIG therapy. Isoagglutinins originating in donor plasma are believed to play a major role in these reactions, but host factors are also important. We determined the effects of excluding plasma from donors with high isoagglutinin titers from the pools used to prepare IVIG, and of specific anti-A/B immunoaffinity chromatography (IAC), on the anti-A and anti-B titers of IVIG products prepared using the process for Privigen/Hizentra.

Absence of in vitro Procoagulant Activity in Immunoglobulin Preparations due to Activated Coagulation Factors

Background: Immunoglobulin (IG) products, including intravenous (IVIG) or subcutaneous (SCIG) immunoglobulins are considered safe and effective for medical therapy; however, a sudden and unexpected increase in thromboembolic events (TE) after administration of certain batches of IVIG products has been attributed to the presence of activated coagulation factors, mainly factor XIa. Our aims were to examine the presence of enduring procoagulant activity during the manufacturing process of IGs, with special focus on monitoring factor XIa, and to evaluate the presence of in vitro procoagulant activity attributed to coagulation factors in different lots of IVIG and SCIG. Methods: Samples of different steps of IG purification, 19 lots of IVIG and 9 of SCIG were analyzed and compared with 1 commercial preparation of IVIG and 2 of SCIG, respectively. Factors II, VII, IX, XI and XIa and non-activated partial thromboplastin time (NAPTT) were assayed. Results: The levels of factors II, VII, IX, X and XI were non-quantifiable once fraction II had been re-dissolved and in all analyzed lots of IVIG and SCIG. The level of factor XIa at that point was under the detection limits of the assay, and NAPTT yielded values greater than the control during the purification process. In SCIG, we detected higher concentrations of factor XIa in the commercial products, which reached values up to 5 times higher than the average amounts found in the 9 batches produced by UNC-Hemoderivados. Factor XIa in commercial IVIG reached levels slightly higher than those of the 19 batches produced by UNC-Hemoderivados. Conclusion: IVIG and SCIG manufactured by UNC-Hemoderivados showed a lack of thrombogenic potential, as demonstrated not only by the laboratory data obtained in this study but also by the absence of any reports of TE registered by the post marketing pharmacovigilance department.

Development of an intravenous immunoglobulin with improved safety and functional activity

The development and properties of a liquid intravenous immunoglobulin (Gammaplex®), of high purity, stability and functional activity, is described. Virus and TSE reduction by specific steps in the process were evaluated by spiking studies using small-scale models. The removal of procoagulant activity was determined using immunochemical and functional activity assays. Neutralisation and opsonic activity were used to demonstrate the functional activity of the IgG. The final low pH formulated product was stable at room temperature and was of high purity and functional activity. Three dedicated virus inactivation steps, i.e. solvent detergent, low pH and virus filtration, were shown to be effective. When combined with the B + I ethanol precipitation step, this gave a total reduction of >21 to >24 log for the enveloped and >10 to >13 log for the non-enveloped viruses tested. Several steps in the process were shown to contribute to TSE removal using scrapie. Potential procoagulant activity including Factor XI/XIa, was reduced to very low/undetectable levels in the final product. A new high purity liquid IVIG product has been developed, of high purity and good functional activity and stability. The process includes various steps for the removal of pathogens and procoagulant activity.

Assessment of in vivo safety of IVIG products: Evaluation of sensitivity and specificity in a modified venous stasis rabbit model

Assessment of in vivo safety of IVIG products: Evaluation of sensitivity and specificity in a modified venous stasis rabbit model

Hemolysis After High Dose IVIG In Blood Group A Women With Alloimmune Thrombocytopenia

IntroductionHemolysis after IVIG infusion has been observed in clinical trials and case reports. Certain factors seem to place a patient receiving IVIG at higher risk for hemolytic anemia: 1) having blood type A, B, or AB and 2) receiving high doses of IVIG (≥ 2g/kg).IVIG contains isohemagglutinins that coat red blood cells and may cause red cell clearance by the RES (Table 1). Anti-A, Anti-B, and Anti-D titers have been detected in IVIG products at varying concentrations by different IVIG manufacturers. It has been suggested that Anti-A titers > 1:16 are more likely to cause clinically significant hemolysis and thus anemia in recipients.Table 1Anti-A Titer Levels by IVIG PreparationIVIG BrandAnti-A TiterGammagard liquid1:64Privigen 10%1:64Gamunex 10%1:32Octagam 10%1:8 - 1:32Gamimune-N1:8Octagam 5%1:2 - 1:8Carimune 9%1:4Table 2IVIG-Associated Hemolysis by Blood Type (BT)Blood TypePercent Experiencing HemolysisBlood Type Prevalence in USA61.9%40%B17.5%11%AB12.7%4%O4.8%45%15 summarized studies reported 63 patients who experienced hemolysis after IVIG infusion and showed the higher risk of non-group O recipients to hemolyze with IVIG:In the current study, we sought to explore the degree of anemia as related to ABO blood types in mothers treated with IVIG for fetal alloimmune thrombocytopenia (AIT). MethodsA retrospective chart review was conducted on 84 women who had received IVIG for AIT treatment during their pregnancy to increase the fetal platelet count. Women were randomized to receive IVIG 2g/kg/wk (arm A, n=43) or IVIG 1g/kg/wk + prednisone (arm B, n=41) starting at 20-30 weeks of gestation until delivery. One CBC per month was collected from each mother from the start of treatment until delivery. Hemoglobins and mean corpuscular volumes (MCVs) were tracked and development of anemia was compared among women with blood types (BT) A, B, AB and O in each treatment arm. Patients who non-randomly received IVIG 2g/kg/wk + prednisone together as rescuetreatment were excluded from this study. Results36 of the 84 women had hemoglobins less than 10 on at least one CBC during IVIG treatment. All 36 had MCV values in the normocytic range (80-100). The degree of anemia was significantly greater in Arm A (IVIG 2g/kg) than Arm B (IVIG 1g/kg + pred) (Fisher's exact test, p=0.016; table 3).Table 3Degree of Hemolysis among treatment armsArm A (IVIG 2g/kg/wk)Arm B (IVIG 1g/kg/wk + Prednisone 0.5 mg/kg/d)Hg<102412Hg≥101929Among women in arm A (IVIG 2g/kg), BT non-O had a significantly higher incidence of marked anemia (Hg<10) than those with BT O (Fisher's exact test, p=.001; table 4), with BT A having the highest number of women with Hg<10 (A=16, B=1, AB=1, O=4, unknown=2).There was no significant difference among women by blood type O (n=4) versus non-O (A=4,B=2,AB=0,unknown=2) in the incidence of anemia in arm B (IVIG 1g/kg + pred); both BT groups showed a low incidence of hemolysis (table 5).Table 4IVIG 2g/kg/wk (Arm A)Blood type OBlood type Non-OHg<10420Hg≥10136Table 5IVIG 1g/kg/wk + Pred (Arm B)Blood type OBlood type Non-OHg<1048Hg≥101415 ConclusionsPatients who were on 2g/kg/wk IVIG became substantially more anemic than those on the 1g/kg/wk IVIG + prednisone dose, which supports reported findings that higher dose (HD) IVIG is associated with a greater risk of anemia. Note: receiving IVIG 2g/kg/wk for multiple weeks is very high dose IVIG. In particular, those patients receiving HD IVIG who were BT A had a greater risk of developing a greater extent of anemia than those of blood type O. This finding is consistent with the hypothesis that blood-group specific antibodies in IVIG result in immune hemolysis primarily in BT A recipients because of the higher anti-A titers. Furthermore, while 1 g/kg/wk of IVIG is not “low dose”, the concomitant use of prednisone 0.5mg/kg/d may protect against development of a greater degree of anemia in these patients.IVIG is the standard of care treatment for AIT; however 1 g/kg/wk is known not sufficiently effective in severely thrombocytopenic fetuses (Berkowitz, OB-GYN 2006). Therefore we believe appropriate treatment of women whose previous babies did not have an ICH needs to be > 1g/kg/wk. Our study found that hemolytic anemia in non-O blood types may be an important side effect of 2g/kg/wk IVIG treatment, indicating that patient blood type should be considered when deciding which IVIG regimen to use. Disclosures:Bussel:Shionogi: Membership on an entity's Board of Directors or advisory committees, Research Funding; Eisai: Membership on an entity's Board of Directors or advisory committees, Research Funding; Ligand: Membership on an entity's Board of Directors or advisory committees, Research Funding; Immunomedics: Research Funding; IgG of America: Research Funding; Genzyme: Research Funding; Cangene: Research Funding; GlaxoSmithKline: Equity Ownership, Membership on an entity's Board of Directors or advisory committees, Research Funding; Amgen: Equity Ownership, Membership on an entity's Board of Directors or advisory committees, Research Funding; Sysmex: Research Funding; Symphogen: Membership on an entity's Board of Directors or advisory committees.

GRP-007 A Retrospective Survey of Patient Outcomes After Switching Intravenous Immunoglobulin

BackgroundThe market place for human immunoglobulins is constantly evolving and reacting to instability of supply of the raw material. This has meant new products emerging as well as old products...

CD44 Antibody Mediated Amelioration of Murine ITP: Evidence for a Similar Strain Dependent FcγRIIB Requirement As Compared to Ivig

AbstractAbstract 1084We have previously demonstrated that monoclonal antibodies to the CD44 antigen can ameliorate murine ITP as successfully as IVIg. We have also shown that, similar to IVIg, these antibodies do not require expression of the neonatal Fcγ receptor FcRn. Unlike IVIg, however, CD44 antibodies do not require the Fc portion to function in the murine ITP model. A lack of requirement for the Fc region of CD44 antibodies would indicate that Fcγ receptors should not be necessary for antibody function, but CD44 antibodies do not ameliorate ITP in FcγRIIB deficient mice (B6;129S-Fcgr2btm1Ttk/J). Recent data from some groups have suggested that IVIg can in fact ameliorate murine ITP in the absence of FcγRIIB, depending on the background strain of the mouse. These data cast doubt on the simplistic view that IVIg ameliorates murine ITP by upregulating macrophage FcγRIIB expression.The requirement for the expression of the inhibitory IgG receptor FcγRIIB has been a prominent theory as to how IVIg ameliorates ITP. Similar to IVIg, the CD44 antibody KM114 does not function in B6;129S-Fcgr2btm1Ttk/J FcγRIIB deficient mice. Another IVIg product which has ameliorative effects similar to IVIg but appears to function via a different mechanism is anti-D. We have previously shown that IVIg and a monoclonal antibody with “anti-D like” activity, TER-119, can successfully ameliorate thrombocytopenia in a murine model of ITP. In contrast to KM114 and IVIg, TER-119 is fully functional in B6;129S-Fcgr2btm1Ttk/J mice. To further characterize the therapeutic CD44 antibody KM114, we have analysed KM114 function in FcγRIIB deficient mice on 3 different backgrounds. Specifically, mice were pretreated with nothing, 50 ug KM114, 50 mg IVIg, or 50 ug TER-119 thirty min prior to administration of the anti-platelet antibody MWReg30.Here, we have confirmed that TER-119, but not KM114 or IVIg, successfully ameliorates murine ITP in B6;129S-Fcgr2btm1Ttk/J mice. These mice are not fully congenic, and have been reported to be approximately a 50:50 mix of B6 and 129S4 (Leontyev, et. al Blood. 31;119(22):5261-4). To investigate whether or not KM114 required the presence of FcγRIIB in mice from different backgrounds, we next employed B6.129S4-Fcgr2btm1TtK N12 FcγRIIB deficient mice, which, unlike B6;129S-Fcgr2btm1Ttk/J mice, are congenic on the B6 background. KM114 and IVIg were both effective in treating thrombocytopenia in these mice. TER-119 was also effective, as expected. To further explore these findings, we next employed FcγRIIB deficient mice which are congenic on the BALB/C background, C.129S4(B6)-Fcgr2btm1TtK/cAnNTac N12 mice. Again, we found that KM114, IVIg and TER-119 were all effective in treating thrombocytopenia in these mice.As KM114 functions in congenic B6.129S4-Fcgr2btm1TtK N12 and C.129S4(B6)-Fcgr2btm1TtK/cAnNTac N12 mice, but not in mixed background B6;129S-Fcgr2btm1Ttk/J mice, these data suggest that rather than FcγRIIB expression being necessary, it may be the mouse background genes that affect KM114’s ability to function. Further experiments using mice of different genetic backgrounds may assist in understanding these findings. [Display omitted] Disclosures:No relevant conflicts of interest to declare.

Ivig, but Not a Monoclonal Anti-RBC Antibody, Requires the Presence of Gr-1+ Cells to Ameliorate Immune Thrombocytopenia in a Murine Model

AbstractAbstract 268Although there are many theories as to the mechanism of action of IVIg in the treatment of autoimmune disease, the exact pathway by which IVIg functions remains unclear. Many cell populations have been implicated in the IVIg pathway, including dendritic cells, which are considered to be one of the central initiators of IVIg effects, and macrophages, which are involved in platelet destruction. In addition, there is evidence from several groups that additional intermediary cell types may be involved. IVIg administration can induce a suppressive effect on peripheral blood neutrophil counts in ITP patients. In fact, alloimmunized thrombocytopenic patients, who display low neutrophil counts, do not respond to IVIg therapy.Here, we questioned whether Gr-1+cells (consisting primarily of neutrophils) are a critical cell type required for IVIg function, in a murine model of ITP. Another IVIg product which has ameliorative effects similar to IVIg but appears to function via a different mechanism is anti-D. We have previously shown that IVIg and a monoclonal antibody with “anti-D like” activity, TER-119, can successfully ameliorate thrombocytopenia in a murine model of ITP. In human patients as well as murine models of ITP, these 2 therapeutics appear to function via different mechanisms. Some work has shown that IVIg and anti-D work by the same, or overlapping mechanism, while other work shows a notable difference in that IVIg can cause neutropenia under conditions where it works to ameliorate autoimmune inflammation.Mice pretreated with 50 mg IVIg (∼2g/kg), or 50 ug TER-119 thirty min prior to administration of anti-platelet antibody MWReg30, show protection from thrombocytopenia compared with untreated mice. To assess the potential role for Gr-1+ cells in IVIg vs TER-119 mediated amelioration of murine ITP, we used RB6-8C5, a well described rat antibody for Gr-1+ cell depletion. Mice were injected with RB6-8C5 or control rat IgG 24 hr prior to thrombocytopenia induction. Mice pretreated with RB6-8C5 failed to respond to IVIg therapy compared with control mice. In contrast, Gr-1+ cell depletion had no effect on the ability of TER-119 to ameliorate the thrombocytopenia. This suggests that Gr-1+ cells likely play an essential role in IVIg function. In contrast, TER-119, does not depend on the presence of Gr-1+cells, suggesting that the mechanisms of action for IVIg and RBC specific antibodies are different for this requirement.In line with these observations, it has been observed that IVIg can modulate neutrophil activity, suggesting that in the murine ITP model, IVIg may function through a neutrophil dependent pathway. Experiments using more specific granulocyte antibodies will help ascertain whether neutrophils or some other Gr-1+ cell population is involved in IVIg function. Disclosures:No relevant conflicts of interest to declare.