Subcutaneous IgG Research Articles

Quality of Life Evaluation in Saudi Arabian Pediatric Patients with Primary Immunodeficiency Diseases Receiving 20% Subcutaneous IgG Infusions at Home.

Subcutaneous immunoglobulin (SCIG) home infusion is widely used as an alternative to intravenous immunoglobulin (IVIG). This study aimed to determine the quality of life (QoL) of patients with primary immunodeficiency (PID) after switching to home-based SCIG. In this prospective open-label single-center study, QoL was determined using the validated Arabic version of the Child Health Questionnaire at baseline and 3 and 6 months after switching from IVIG to SCIG. Twenty-four patients were recruited from July 2018 to August 2021, including 14 females and 10 males. The median age of the patients was 5 years (range, 0-14 years). The patients' diagnoses included severe combined immunodeficiency, combined immunodeficiency, agammaglobulinemia, Omenn syndrome, immunodysregulation, hyper-IgE syndrome, common variable immunodeficiency, and bare lymphocyte syndrome. The median duration on IVIG before inclusion was 40 months (range, 5-125 months). The QoL score showed a significant improvement in the patients' global health at 3 and 6 months compared with those at baseline and a significant improvement in the patients' general health at 3 and 6 months compared with that at baseline. The mean baseline serum IgG trough level was 8.8 ± 2.1 g/L. The mean serum IgG level was significantly higher on SCIG at both 3 and 6 months (11.7 ± 2.3 and 11.7 ± 2.5 g/L, respectively). This is the first study involving an Arab population to show improvement in the QoL of patients with PID after switching from hospital-based IVIG to home-based 20% SCIG.

Surveillance of anti-SARS-CoV-2 antibodies in plasma pools and in immunoglobulin medicinal products manufactured since 2020 has shown high neutralizing activity against SARS-CoV-2 and current variants

BackgroundPatients with primary and secondary immunodeficiencies have shown an impaired humoral immune response to COVID-19 vaccination. It is therefore of paramount importance to investigate anti-SARS-CoV-2 antibody levels in plasma pools and in immunoglobulin (IgG) products used to treat these patients. AIM: To assess the evolution of anti-SARS-CoV-2 antibodies (S protein) in plasma pools and IgG products and its neutralizing activity to original-type virus (Wuhan) and the variants of concern (VOC), including Omicron. MethodsHealthy donors plasma pools collected in the US and Europe, and the subsequent intravenous (Flebogamma DIFand Gamunex-C, Grifols) and subcutaneous (Xembify, Grifols) IgG manufactured batches were followed from March 2020. Anti-SARS-CoV-2 S protein IgG titers were determined in plasma pools and in IgG batches by ELISA. Neutralization assays analyzed the capacity of IgG products to neutralize original-type virus and VOC (Alpha, Beta, Delta, Omicron BA.1 and BA.5), using pseudo viruses expressing S protein. Results were expressed as the dilution producing 50% neutralization (ID50). ResultsIn plasma pools, anti-SARS-CoV-2 S antibodies continuously increased throughout the study period regardless of the geographic origin. In the US, the first positive plasma pools were collected at the end of 2020. Since July 2021, an exponential increase over 30-fold of anti-SARS-CoV-2 S antibodies was reported. This trend continued increasing until the end of study period. Similarly, IgG products showed a similar evolution of anti-SARS-CoV-2 S antibodies. As expected, IgG batches released at the end of 2020 presented low SARS-CoV-2 neutralization activity. However, IgG products manufactured since August 2021 showed high neutralization activity against original-type virus and the rest of VOC. Regarding Omicron BA.5, a 5 to 10-fold increase was observed over time. ConclusionThis study reported the onset of elevated anti-SARS-CoV-2 antibody titers in plasma pools and IgG products since mid-2021, reflecting the evolution of the pandemic and vaccine campaigns. Intravenous and subcutaneous IgG products efficiently neutralized the current circulating VOC, Omicron BA.5. Further research is warranted to assess whether a clinical protective titer against SARS-CoV-2 and passive immunization is achieved in patients with immunodeficiencies treated with IgG products.

Normal LRBA expression in a patient with LRBA deficiency: Understanding the clinical test

An 11-year-old girl presented as a new immunology patient with a history of celiac disease, inflammatory bowel disease, asthma, chronic bilateral otitis, autoimmune hemolytic anemia, and chronic splenomegaly. In addition, she had generalized lymphadenopathies and chronic lung disease (bronchiectasis, ground glass infiltrates, and nodular opacities). Relevant laboratory findings included anemia, neutropenia, elevated ESR (62), positive ANAs (1:320), poor antibody responses and hypogammaglobulinemia, slightly elevated αβ+double negative T-cells (1.6%) and serum soluble CD25 levels (9560 pg/mL). Parents are consanguineous and genetic testing reveals a homozygous pathogenic variant in LRBA (c.5980C>T). This is a novel defect predicted to cause a premature translational stop signal (p. Arg1994*), resulting in an absent or disrupted protein. The patient responded favorably to abatacept and subcutaneous IgG replacement with resolution of lymphadenopathies, organomegaly and cytopenias, improvement of infections and gastrointestinal symptoms, and decrease in inflammatory markers and serum soluble CD25 levels. Unexpectedly, during her evaluation, flow cytometry to assess intracellular LRBA using a polyclonal rabbit antibody (Sigma-Aldrich) showed protein expression in 100% of T-cells and 99% of B-cells. Since the patient’s clinical and genetic findings and her response to abatacept indicated LRBA deficiency, we reassessed LRBA expression using a different assay with an anti-LRBA monoclonal antibody recognizing the protein N-terminal (Clone 2D4.1, Milipore). This assay showed essentially absent expression of LRBA in T-cells (1.7% in CD4+ and 11.5% in CD8+), B-cells (3.6%), and NK-cells (0.8%), fitting with both our genetic findings and clinical phenotype. Hence, assays detecting LRBA expression may have discrepant results and understanding the technicalities of how they are performed is critical for their interpretation and avoiding potential pitfalls. For instance, it is possible that epitopes targeted by a polyclonal antibody could still be identified on a mutated LRBA protein, yielding normal protein phenotyping levels in LRBA deficient patients. Presence of protein also does not equate to functional protein but a validated functional clinical test for LRBA is yet unavailable. In conclusion, this case underscores the importance of using genetic and functional data in the context of the clinical phenotype for IEI diagnosis.

Increased Access to Immunoglobulin Replacement Therapy for Patients with Primary Immunodeficiency in Poland Based on Clinical Usage Data of Immunoglobulin G over a 5-Year Period

Owing to the rising popularity and demand for immunoglobulins (IgG), obtaining supplies and rationalizing IgG use have become challenging. Herein, IgG consumption in Poland was analyzed through total IgG use and number of patients reported to the National Health Fund between 1 January 2016 and 31 December 2020. Total IgG used within 5 years increased by 27.48%, IgG use/1000 inhabitants/year was 23.13 g (2016) and 29.61 g (2020). In 2020, 35.5 % of IgG used was for neurological conditions, 25% for primary immunodeficiencies (PID), and 39.3% for all other indications. Within 5 years, 1,121,168.75 g IgG was used in PID; the use increased by 72%, from 783 in 2016 to 1153 patients in 2020. The proportion of patients who received subcutaneous immunoglobulin (SCIG) replacement therapy (IgRT) increased to 78% (2020). Within 5 years, 1,783,534.81 g IgG was used in neurological drug programs (+42.44%) and 2,327,513.88 g (+1.25%) outside neurological indications and outside PID. The annual IgG amount decreased in adult anesthesiology and intensive care (-46%), internal medicine (-55%), pneumonology (-50%), pediatric clinical immunology (-50%), and gynecology and obstetrics (-48%) and increased in dermatology (+178%), rheumatology (+103%), and clinical transplantation (+82%). IgG use significantly increased in Poland, mostly owing to PID. Subcutaneous IgG administration is currently the most common mode of IgRT in PID patients. An increase in SCIG administration may be expected for other indications. Implementing evidence-based clinical guidelines is key to prioritizing and rationalizing IgG use for immunomodulatory indications and secondary immune deficiencies.

Economic impact of self-administered subcutaneous versus clinic-administered intravenous immunoglobulin G therapy in Alberta, Canada: a population-based cohort study

BackgroundSelf-administered subcutaneous immunoglobulin G (SCIg) reduces nursing time and eliminates the need for treatment at ambulatory care clinics, as compared with clinic-based intravenously administered IgG (IVIg), and are therapeutically equivalent. Estimating the economic impact of self-administered SCIg versus clinic-administered IVIg therapy may guide treatment recommendations.MethodsA retrospective population-based cohort study using administrative data from Alberta was performed; those treated with IgG between April 1, 2012 and March 31, 2019 were included. Costs for medical laboratory staff and nursing time, as well as ambulatory care visits were considered. Univariate generalized linear model regression with gamma distribution and log link was used to compare cost ($CDN 2020) between SCIg and IVIg administration. Stratified analysis by age (≥ 18-years; < 18-years) was performed.ResultsAmong 7,890 (6,148 adults; 1,742 children) individuals who received IgG, the average administration cost per patient-year of self-administered SCIg was $5,386 (95% confidence interval [CI] $5,039, $5,734) lower than clinic-administered IVIg; per patient-year cost of self-administered SCIg was $817 (95% CI $723, $912) versus $6,204 (95% CI $6,100, $6,308) for clinic-administered IVIg. The per patient-year cost of self-administered SCIg was $5,931 (95% CI $5,543, $6,319) lower among adults and $3,177 (95% CI $2,473, $3,882) lower among children compared with clinic-administered IVIg. An estimated $31.0 million (95% CI $29.0, $33.0) in cost savings to the health system would be realised if 80% of individuals switched from clinic-administered IVIg to self-administered SCIg.ConclusionsSelf-administered SCIg is substantially less costly from a health care payer perspective in Canada. Within this type of health system, switching to self-administered SCIg has the potential to reduce overall health care costs, lessen nursing burden, and may increase clinic-based capacity for others.

RESULTS OF A PHASE 4 STUDY OF IMMUNOGLOBULIN [HUMAN] SUBCUTANEOUS FOR PATIENTS REQUIRING IMMUNOGLOBULIN

<h3>Introduction</h3> Immunoglobulin (Ig) therapy has transformed into the preferred treatment for patients diagnosed with various conditions that attack and disable the immune system. Originally, immunoglobulin therapy could only be administered intravenously, but subcutaneous IgG (SCIg) has become a standard of care. This study compares immunoglobulin [human] subcutaneous 16.5% to other currently marketed SCIg products. <h3>Methods</h3> The study was designed to enroll 150 male or female patients with immune dysfunction in one of 3 study arms. Arm 1 enrolled patients naïve to Ig therapy; arm 2 enrolled patients currently receiving IVIG therapy; and arm 3 enrolled participants receiving other SCIg products. Participants receiving SCIg continued on their current product for Visit 1 and Visit 2, with the option of switching to the test product for Visit 3 – Visit 7. After screening, the length of study participation is approximately 6 months. Data regarding number of infusions, laboratory measurements, rate of infection, and quality of life (using 4 mental health questionnaires) were collected every 4 weeks (±3 days). <h3>Results</h3> The study currently has 45 actively enrolled patients. Patients had an average IgG serum quantitative value of 960.55 in arm 1, 1084.27 in arm 2, and 1231.34 in arm 3. Patients in arm 3 had been on therapy longer, which might explain their higher trough levels, although efficacy was seen in all 3 arms. Additionally, patients reported greater quality of life during the study. <h3>Conclusion</h3> Preliminary results suggest a link between higher IgG levels and greater reported quality of life. Further data is forthcoming.

Antibody response after COVID-19 vaccination in intravenous immunoglobulin-treated immune neuropathies.

BackgroundThis study assessed the prevalence of anti‐SARS‐CoV‐2 antibodies in therapeutic immunoglobulin and their impact on serological response to COVID‐19 mRNA vaccine in patients with intravenous immunoglobulin (IVIg)‐treated chronic immune neuropathies.MethodsForty‐six samples of different brands or lots of IVIg or subcutaneous IgG (SCIg) were analyzed for anti‐SARS‐CoV‐2 IgG using ELISA and chemiluminescent microparticle immunoassay (CMIA). Blood sera from 16 patients with immune neuropathies were prospectively analyzed for anti‐SARS‐CoV‐2 IgA, IgG, and IgM before and one week after IVIg infusion subsequent to consecutive COVID‐19 mRNA vaccine doses and after 12 weeks. These were compared to 42 healthy subjects.ResultsTwenty‐four (52%) therapeutic immunoglobulin samples contained anti‐SARS‐CoV‐2 IgG. All patients with immune neuropathies (mean age 65 ± 16 years, 25 % female) were positive for anti‐SARS‐CoV‐2 IgG after COVID‐19 vaccination. Anti‐SARS‐CoV‐2 IgA titers significantly decreased 12‐14 weeks after vaccination (p=0.02), IgG titers remained stable (p=0.2). IVIg did not significantly reduce intra‐individual anti‐SARS‐CoV‐2 IgA/IgG serum titers in immune neuropathies (p=0.69). IVIg‐derived anti‐SARS‐CoV‐2 IgG did not alter serum anti‐SARS‐CoV‐2 IgG decrease after IVIg administration (p=0.67).ConclusionsOur study indicates that IVIg does not impair the antibody response to COVID‐19 mRNA vaccine in a short‐term observation, when administered a minimum of two weeks after each vaccine dose. The infusion of current IVIg preparations that contain anti‐SARS‐CoV‐2 IgG does not significantly alter serum anti‐SARS‐CoV‐2 IgG titers.

Development of no-wash, rapid Fcγ Receptor Binding Immunoassays using NanoBiT® Technology

Abstract Antibody driven therapies including monoclonal antibodies (mAbs), intravenous IgG (IVIG), subcutaneous IgG (SCIG), and vaccines have made a significant impact in the treatment of many diseases including multiple cancers and autoimmune, metabolic, viral, and infectious diseases. A key mechanism of action (MOA) that makes antibody-based therapies so effective is the ability of the Fc domain of the antibody to recruit immune effector cells through their interaction with a variety of Fc receptors (FcγR). However, assessing the combined impact of interaction of the Fc domain of various antibody isotypes with diverse FcγRs (Fc/FcγR interaction) on the efficacy of the drug is challenging, primarily due to the lack of simple to use and reproducible Fc/FcγR binding assays. Furthermore, existing technologies like SPR can introduce artifacts based on assay format, sensor chip characteristics, and immobilization methods. To meet the need for reliable, simple to use assays, we have developed a suite of bioluminescent biochemical assays for the following receptors: Lumit™ FcγRI Binding ImmunoassayLumit™ FcγRIIA (H131) Binding ImmunoassayLumit™ FcγRIIA (R131) Binding ImmunoassayLumit™ FcγRIIIA (V158) Binding ImmunoassayLumit™ FcγRIIIA (F158) Binding Immunoassay These assays are homogeneous, meaning no immobilization or washing steps are required. In addition, they are rapid, easy to use in a 96-well format, and require a simple luminometer. These assays can enable better understanding of antibody MOA and hence better therapies.

SCIG administration: A promising and patient convenient alternative for those receiving long-term IVIG.

Background: Intravenous immunoglobulin (IVIG) therapy has been used as antibody replacement therapy in primary immunodeficiency diseases (PID) for more than 50 years. In this study, we aimed to define IVIG usage and adverse reactions and complications in PID and explain how subcutaneous immunoglobulin (SCIG) replacement therapy is an alternative that improves the patient experience. In addition, the additional nursing responsibilities associated with this service were also identified.Methods: Data and service satisfaction surveys for the last 10 years were reviewed from the Allergy and Immunology Division log registry for those on IVIG and SCIG.Results: IVIG practice: Most patients currently on IVIG in our unit have PID. Adverse reactions occur during the initial 30 to 60 minutes of the infusion and are mild and self-limited. Infusion reactions are more likely to occur in patients receiving IVIG for the first time. Infusion-related complications included pyrogenic reactions, allergic reactions, and vasomotor symptoms. Complications reported in the literature such as the transmission of blood-borne pathogens and other serious complications, including thrombotic events, renal adverse events, and aseptic meningitis were never reported. Pyrogenic reactions occurred at a rate ≥ 100 mL/hr in at least 3 patients, and a slower infusion rate of ≤ 75 mL/hr mitigated this rate-related complication.SCIG program: This program started in Qatar in 2017. Usually, the clinician assesses and evaluates several factors to help select candidates for this therapy, including the perceptions of inconvenience and/or pain of IV infusions, presence of difficult vein access, and other relevant clinical and social factors. Once training in the appropriate techniques has been accomplished (3–6 sessions), it is most often self-administered in the home setting by the patient or a parent for a child. Table 1 summarizes patients on SCIG.Additional nursing responsibilities: The nursing role in subcutaneous IgG administration is primarily that of an educator and to help the patient/family become independent. This can be achieved by the assessment of appropriate patient selection for self-administration. Determining which patients are suitable include adequate patient education with return demonstration of the necessary skill set, monitoring parameters, educating patients about their medication, and providing educational resources and support.Conclusion: SCIG administration can be a convenient alternative for patients with PID receiving long-term IVIG.

Pharmacokinetic modeling and simulation of subcutaneous and intravenous IgG dosing in patients with primary immunodeficiency diseases

A population pharmacokinetic (PK) model for comparing the PK of subcutaneously administered immunoglobulin G (IgG) replacement therapy (SCIG) with Gamunex-C 10% or SCIG 20% formulations in patients with primary immunodeficiency diseases was developed using data from 3 clinical trials (N = 95, 69.5% adults, 30.5% <18 years) of intravenous IG (IVIG) 10% and SCIG 10% or SCIG 20%. Serum IgG exposure following switches from IVIG 10% every 3 or 4 weeks to biweekly SCIG 20% (dose adjustment factor 1.0 or 1.37) and from weekly SCIG 20% to biweekly SCIG 20% or SCIG 20% 2–7 times/week was simulated. The PK of IVIG 10% and SCIG 20% were adequately described by a 2-compartment model with first-order absorption rate constant of exogenous IgG from an SC depot compartment into the central compartment and first-order elimination from the central compartment. Switching from IVIG 10% every 4 weeks to biweekly SCIG 20% produced similar serum IgG exposure, with lower peak and higher trough serum IgG concentrations. Switching from IVIG 10% every 3 or 4 weeks to weekly and biweekly SCIG 20% yielded comparable IgG exposure and clinically effective trough IgG concentrations.

Update on Intravenous Immunoglobulin in Neurology: Modulating Neuro-autoimmunity, Evolving Factors on Efficacy and Dosing and Challenges on Stopping Chronic IVIg Therapy

In the last 25 years, intravenous immunoglobulin (IVIg) has had a major impact in the successful treatment of previously untreatable or poorly controlled autoimmune neurological disorders. Derived from thousands of healthy donors, IVIg contains IgG1 isotypes of idiotypic antibodies that have the potential to bind pathogenic autoantibodies or cross-react with various antigenic peptides, including proteins conserved among the “common cold”-pre-pandemic coronaviruses; as a result, after IVIg infusions, some of the patients’ sera may transiently become positive for various neuronal antibodies, even for anti-SARS-CoV-2, necessitating caution in separating antibodies derived from the infused IVIg or acquired humoral immunity. IVIg exerts multiple effects on the immunoregulatory network by variably affecting autoantibodies, complement activation, FcRn saturation, FcγRIIb receptors, cytokines, and inflammatory mediators. Based on randomized controlled trials, IVIg is approved for the treatment of GBS, CIDP, MMN and dermatomyositis; has been effective in, myasthenia gravis exacerbations, and stiff-person syndrome; and exhibits convincing efficacy in autoimmune epilepsy, neuromyelitis, and autoimmune encephalitis. Recent evidence suggests that polymorphisms in the genes encoding FcRn and FcγRIIB may influence the catabolism of infused IgG or its anti-inflammatory effects, impacting on individualized dosing or efficacy. For chronic maintenance therapy, IVIg and subcutaneous IgG are effective in controlled studies only in CIDP and MMN preventing relapses and axonal loss up to 48 weeks; in practice, however, IVIg is continuously used for years in all the aforementioned neurological conditions, like is a “forever necessary therapy” for maintaining stability, generating challenges on when and how to stop it. Because about 35-40% of patients on chronic therapy do not exhibit objective neurological signs of worsening after stopping IVIg but express subjective symptoms of fatigue, pains, spasms, or a feeling of generalized weakness, a conditioning effect combined with fear that discontinuing chronic therapy may destabilize a multi-year stability status is likely. The dilemmas of continuing chronic therapy, the importance of adjusting dosing and scheduling or periodically stopping IVIg to objectively assess necessity, and concerns in accurately interpreting IVIg-dependency are discussed. Finally, the merit of subcutaneous IgG, the ineffectiveness of IVIg in IgG4-neurological autoimmunities, and genetic factors affecting IVIg dosing and efficacy are addressed.

Prevalence of hypogammaglobulinemia and its management with subcutaneous immunoglobulin supplementation in patients after allogeneic hematopoietic stem cell transplantation\u2014a single-center analysis

Secondary immunodeficiencies are frequently observed after allo-HSCT. The efficacy of subcutaneous IgG preparations in this population is unknown. A retrospective single-institution study involved 126 adult patients transplanted in 2012–2019 for hematological malignancies. Patients were tested every 2–3 weeks for plasma IgG concentration during the 1st year after transplantation and supplemented with facilitated subcutaneous immunoglobulin when they either had IgG concentration < 500 mg/dl or between 500 and 700 mg/dl and recurrent infection. The IgG concentration < 500 mg/dL was diagnosed in 41 patients, while 500–700 mg/dL in 25 and altogether 53 patients received IgG supplementation. The median number of IgG administrations was 2. The median time to the first IgG administration after allo-HSCT was 4.1 months, while to the next administration (if more than one was required) 53 days (prophylactic group) and 32 days (group with infections). We did not observe any significant toxicity. Two situations were associated with increased probability of meeting criteria for IgG supplementation: diagnosis of either acute lymphoblastic leukemia (ALL) or chronic lymphocytic leukemia (CLL) (83.8% versus 39.3% for other diagnosis, p = 0.000) and the systemic use of corticosteroids (64.2% versus 31.5% for patients without systemic corticosteroids, p = 0.005). Over 40% of the adult recipients may require at least incidental immunoglobulin supplementation during the first year after allo-HSCT. Low IgG concentrations are associated with inferior outcomes. The subcutaneous route of IgG administration appeared to be safe and may allow for long persistence.

Daratumumab as Salvage Therapy in Pediatric Thoracic Organ Transplantation: An Addition to the Antibody Mediated Rejection Toolbox?

Purpose Antibody mediated rejection (AMR) is difficult to treat and often results in death or graft loss. Therapies targeted at antibodies or B cells are inadequate for decreasing donor specific antibodies (DSA), particularly to MHC class II. Bortezomib, a small molecule proteasome inhibitor targets plasma cells, but has many side effects and unsatisfactory results. Alternatively, we used Daratumumab (DAR), an anti-CD38 monoclonal antibody, in two pediatric transplant (Tx) recipients. Methods Chart review. Results An 18-year-old female with cystic fibrosis had a lung-liver Tx at 12-years-old. Twenty months post-Tx she developed severe AMR and Acute cellular rejection (ACR) treated with ATG, rituximab, TPE, photopheresis, and steroids. She ultimately required redo lung Tx. She did well for three years, but then developed AMR. She again received TPE, ATG, photopheresis, and rituximab. She was not considered a candidate for third lung Tx so all attempts were made to salvage her graft. She had no B cells, but continued to make DSA, so a plasma cell targeted therapy was desired. She received three doses of DAR 16 mg/kg on days 0, 7 and 21 with no infusion reactions. She developed neutropenia 2 months later which resolved with 3 weeks of GCSF. Both total PRA and DSA significantly decreased after DAR and have not returned 7 months later. PRA class I dropped from peak of 96% to 0, class II from peak 34% to 3%. She is maintained on subcutaneous IgG replacement for secondary hypogammaglobulinemia. Her graft function is poor, but has stabilized since DAR. She had one episode of presumed line associated sepsis and MSSA pneumonia without sequalae. A 3-year-old girl two years post heart Tx developed refractory AMR (by C4d and elevated DSA) despite ATG, TPE, IVIG, eculizumab, and ofatumumab. She then received two doses of DAR, 16 mg/kg each on days 0 and 14. She tolerated the infusions without any initial side effects. Not enough time has elapsed to follow up antibody levels or graft function. Conclusion Treatment for AMR remains challenging, especially when due to class II HLA antibodies. We safely administered DAR to two pediatric patients without infusion reactions or significant infectious complications to date. One patient had a decline in antibodies, while the other is too soon to determine. While more studies are needed, DAR may be a promising addition to the AMR toolbox.

Falsely Elevated Creatinine on Enzymatic Assay in a Patient Receiving Subcutaneous IgG Therapy.

Falsely Elevated Creatinine on Enzymatic Assay in a Patient Receiving Subcutaneous IgG Therapy.

Treating secondary antibody deficiency in patients with haematological malignancy: European expert consensus.

Secondary antibody deficiency (SAD), associated with severe, recurrent or persistent infections, is common in patients with haematological malignancies (HM), but unifying guidance on immunoglobulin replacement therapy (IgRT) in these patients is lacking. We aimed to develop consensus statements for the use of IgRT in patients with HM. A Delphi exercise was employed to test the level of agreement on statements developed by a Task Force based on available data and their clinical experience. In Round 1, an Expert Panel, comprising specialist EU physicians caring for patients with HM, helped to refine the statements. In Round 2, experts rated their agreement with the statements. In Round 3, experts who had scored their agreement as ≤4 were invited to review their agreement based on the overall feedback. Three definitions and 20 statements were formulated and tested for consensus, covering measurement of IgG levels, initiation and discontinuation of IgRT, dosing, and the use of subcutaneous IgG. Consensus (agreement ≥70% on Likert-type scale) was reached for all three definitions and 18 statements. Recommendations have been developed with the aim of providing guidance for the use of IgRT to prevent severe, recurrent or persistent infections in patients with HM and SAD.

Use of Subcutaneous IgG to Treat Hypogammaglobinemia in ANCA-Associated Vasculitis

Use of Subcutaneous IgG to Treat Hypogammaglobinemia in ANCA-Associated Vasculitis

Tonsillar granuloma associated with hypogammaglobulinemia

BackgroundRare tonsillar granulomas may be caused for example by infections, malignancies or sarcoidosis. Granulomas also occur in inborn errors of immunity (IEI) such as common variable immunodeficiency (CVID) with B cell maturation defects and hypogammaglobulinemia. CVID shares various features with sarcoidosis and drug-induced secondary hypogammaglobulinemia; careful consideration of differential diagnosis between these conditions is warranted.Case presentationA 29-year-old female with epilepsy developed dysphagia, dyspnea and impaired exercise tolerance. Obstruction caused by swollen lingual tonsil and edema in the epiglottis and arytenoid mucosa were found. Lingual tonsil and epiglottis biopsies displayed non-necrotizing granulomas. There was no evidence of viral, bacterial, mycobacterial or fungal infections. Chest X-ray, computerized tomography of chest and ultrasound of neck and abdomen remained unremarkable. Positron emission tomography/computed tomography (PET/CT) showed laryngeal enhancement. Empiric antimicrobials combined with prednisolone were insufficient to control her disease. In immunological evaluation, the patient had normal counts of B and T cells. Proportions of CD27+ memory B cells (30.3%) and IgD−IgM−CD27+ switched memory B cells (7.2%; normal range 6.5–29.2%) were normal. Percentage of activated CD21low B cells was high (6.6%; normal range 0.6–3.5%). IgG (3.5 g/L; normal range 6.77–15.0 g/l) and all IgG subclass concentrations were low. Anti-polysaccharide responses were impaired, with 3/10 serotypes reaching a level of 0.35 µg/ml after immunization with Pneumovax®. The findings were consistent with hypogammaglobulinemia resembling CVID, possibly secondary to antiepileptic medication. Her dyspnea and dysphagia responded favorably to subcutaneous IgG and rituximab.ConclusionsTonsillar granulomas can be the presenting and only clinical feature of B cell deficiency, highlighting the diversity of symptoms and findings in primary or secondary immunodeficiencies.

Subcutaneous Immunoglobulin for Antibody Deficiency in Antineutrophil Cytoplasmic Antibody (ANCA)-associated Vasculitis.

ObjectivesIntravenous immunoglobulin G (IVIG) is used to treat antineutrophil cytoplasmic antibody (ANCA) patients with recurrent infections as a result of hypogammaglobulinemia (HG) induced by treatment regimens. We sought to characterize clinical features, treatment, and outcomes for patients treated with the novel subcutaneous IgG (SCIG) for the aforementioned purpose. MethodsWe conducted a retrospective study of 136 patients in our ANCA database to identify patients with recurrent infections and HG subsequently treated with SCIG. Patient demographics, serologies, treatment, and immunological parameters were assessed. ResultsOf 136 patients, four were treated with SCIG. All were Caucasian, proteinase-3 (PR3)-positive, and the majority (n = 3) were females. All patients had pulmonary involvement, and regimens of cyclophosphamide (CYC) and/or rituximab (RTX) were employed for induction and remission. Three patients each experienced recurrent bouts of respiratory tract infections and shingles. Ig levels (G, M, and A) were reduced in all patients, except for one patient who had normal IgA levels. CD19/20 cells were depleted and CD3/4/8/NK cells were preserved in all patients. Three patients had no discernible antibody response to the pneumococcal vaccine (specific pneumococcal serotypes measured pre- and post-vaccine). The mean duration elapsed between the first rituximab administration and commencement of SCIG was 7.2 years. The IgG level normalized and none of the patients had a recurrence of infection since the initiation of SCIG. ConclusionThis data, albeit preliminary, is the first series that demonstrates SCIG can be a reliable alternative to IVIG in ANCA patients with recurrent infections secondary to HG. Early identification of this subset of patients is likely to mitigate infectious risks, associated morbidity, and hospitalization.

Immunosuppressive and immunomodulatory therapies for neuromuscular diseases. Part I: Traditional agents.

Immunosuppressive and immunomodulatory therapies have had a major effect on the treatment of immune-mediated neuromuscular diseases. After the landmark introduction of synthetic corticosteroids, other therapies have become available, including plasma exchange (PLEX), immunoglobulin G (IgG), and steroid-sparing immunosuppressive drugs. More recently, novel biologically derived and antigen-specific pharmaceuticals have entered neuromuscular practice. Various levels of evidence guide the use of these treatments. This article reviews current immune-based therapies in neuromuscular diseases and is divided into two parts. Part I provides an update on the evidence and use of traditional therapies, such as corticosteroids, PLEX, intravenously delivered IgG (IVIG), and steroid-sparing immunosuppressive drugs. Part II focuses on the recently US Food and Drug Administration-approved therapies eculizumab and subcutaneous IgG (SCIG), the current indications for rituximab in neuromuscular disease, and on novel immunosuppressive therapeutic approaches under development.

Subcutaneous Immunoglobulin Twenty Percent Every Two Weeks in Pediatric Patients with Primary Immunodeficiencies: Subcohort Analysis of the IBIS Study.

Background: Subcutaneous immunoglobulin G (SCIG) may be a better option than intravenous immunoglobulin G (IVIG) for patients with primary immunodeficiencies (PID) due to reduced systemic and serious adverse reactions and easier administration. The Infusione Bimensile di Immunoglobuline Sottocute (IBIS) study investigated the effects of Hizentra®, a 20%-concentrated SCIG, administered biweekly in patients with PID. This subanalysis aimed to evaluate clinical and laboratory outcomes in the IBIS pediatric subcohort. Methods: Thirteen children with PID were observed for 12 months retrospectively (with previous IVIG/SCIG) and prospectively with biweekly Hizentra. Results: Mean ± standard deviation serum IG levels during the retrospective (833.8 ± 175.7 mg/dL) and the prospective (842.0 ± 188.0 mg/dL) phases were comparable; there were also no differences in the number of infections. Conclusions: Biweekly Hizentra is a noninferior option with respect to previous IVIG/SCIG-based treatment.