Prophylactic immunoglobulin therapy for pediatric congenital myotonic dystrophy.

Congenital Myotonic Dystrophy (CMD) is an autosomal dominant hereditary disease caused by mutations in the dystrophia myotonica protein kinase gene. Patients with CMD often exhibit low immunoglobulin (Ig) G levels. While Ig replacement therapy for low IgG levels has been reported in several adult cases, there have been no reports on pediatric patients. This study presents a first pediatric case where Ig replacement therapy effectively eliminated susceptibility to infections. The CMD patient, a 1-year-old Japanese female with a history of premature birth and necrotizing enterocolitis, developed recurrent severe bacterial infections due to hypogammaglobulinemia. Intravenous immunoglobulin (IVIG) (600 mg/kg/month) was administered but failed to maintain sufficient serum trough IgG levels. The dosage was increased to 2 g/kg/month, and later, the treatment shifted to subcutaneous immunoglobulin (SCIG), resulting in a stable serum trough IgG level above 700 mg/dL for one year. The cause of hypogammaglobulinemia in CMD patients remains unclear, but potential mechanisms, including IgG-mediated hypercatabolism by alterations in the neonatal Fc receptor, have been considered. Genetic testing ruled out common variable immunodeficiency, and other potential causes were excluded. The study suggests that higher doses of IVIG or SCIG can effectively prevent severe infections associated with CMD-induced hypogammaglobulinemia in children.

This case report sheds light on the efficacy of immunoglobulin therapy in pediatric congenital myotonic dystrophy (CMD). We anticipate that our findings will have a positive impact on clinical practice by providing insights into the prevention of severe infections associated with CMD-induced hypogammaglobulinemia. This research is of great interest to the readers of the journal as it addresses an unmet need in pediatric CMD management by providing a strategy for successful immunoglobulin therapy for the treatment of pediatric CMD.

Mild COVID-19 in an APECED Patient with Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) and High Titer of Type 1 IFN-Abs: A Case Report.

Autoimmune-Poly-Endocrinopathy-Candidiasis-Ectodermal Dystrophy (APECED), caused by mutations in the Autoimmune Regulator (AIRE) gene, is an autosomal recessive multi-organ autoimmunity syndrome usually defined by high serum titers of type I Interferon Autoantibodies (Type 1 IFN-Abs). These antibodies have recently been found in individuals in the general population who develop life-threatening Coronavirus Disease 2019 (COVID-19), but the significance of pre-existing Type 1 IFN-Abs in APECED patients with COVID-19 remains unclear. Previous reports of COVID-19 outcomes in APECED patients have been divergent, and protective roles have been proposed for female sex, age <26 years, and immunomodulatory medications including intravenous immunoglobulin (IVIg). We report the case of a 30-year-old male APECED patient who experienced a Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection with mild symptoms of fatigue and headache without respiratory distress and did not require hospitalization. He received a stress dose of hydrocortisone for adrenal insufficiency and continued on his baseline medications, including subcutaneous administration of Immunoglobulins (SCIgs) for chronic inflammatory demyelinating polyneuropathy (CIDP). Mild COVID-19 in a 30-year-old male patient with APECED and pre-existing Type 1 IFN-Abs was unexpected. Younger age and management of autoimmunity may have played a role.

Intravenous and subcutaneous immunoglobulins-associated eczematous reactions occur with a broad range of immunoglobulin types: A French national multicenter study.

BACKGROUND: Human immunoglobulins are used for treating diverse inflammatory and autoimmune disorders. Eczema is an adverse event reported but poorly described. OBJECTIVES: To describe the clinical presentation, severity, outcome, and therapeutic management of immunoglobulin-associated eczema. METHODS: This retrospective and descriptive study included a query of the French national pharmacovigilance database, together with a national call for cases among dermatologists. RESULTS: We included 322 patients. Eczema occurred preferentially in men (78.9%) and in patients treated for neurological pathologies (76%). The clinical presentation consisted mainly of dyshidrosis (32.7%) and dry palmoplantar eczema (32.6%); 5% of cases exhibited erythroderma. Sixty-two percent of the eczema flares occurred after the first immunoglobulin course. Eczema was observed with 13 intravenous or subcutaneous immunoglobulin types and recurred in 84% of patients who maintained the same treatment and in 68% who switched the immunoglobulin type. After immunoglobulin discontinuation, 30% of patients still had persistent eczema. LIMITATIONS: Retrospective study, with possible missing data or memory bias. CONCLUSION: Immunoglobulin-associated eczema occurred with all immunoglobulin types, preferentially in patients with neurologic diseases who required prolonged immunoglobulin treatment. Recurrence was frequent, even after switching the immunoglobulin type, which can lead to a challenging therapeutic situation when immunoglobulin maintenance is required.

Hipogammaglobulinemia crónica postrasplante de precursores hematopoyéticos y su tratamiento con gammaglobulina subcutánea en pacientes pediátricos / Chronic hypogammaglobulinemia after allogeneic stem cell transplantation and their treatment with subcutanaeos inmunoglobulin in pediatric patients

Introducción: La hipogammaglobulinemia en los primeros meses postrasplante de progenitores hematopoyéticos (TPH) es común en pacientes pediátricos. Durante esta fase se debe administrar tratamiento sustitutivo con inmunoglobulina humana por vía parenteral para la prevención de infecciones. En algunos casos, esta hipogammaglobulinemia persiste en el tiempo, lo que obliga a prolongar el tratamiento cuando el paciente ya no suele ser portador de una vía central, por lo que son candidatos ideales para el tratamiento de reemplazo por vía subcutánea. Existe escasa bibliografía publicada que describa el uso de esta vía en pacientes pediátricos sometidos a TPH; sin embargo, está ampliamente descrita y con muy buenos resultados en el tratamiento de reemplazo en los niños con inmunodeficiencias primarias. Pacientes y métodos: Se realiza un estudio observacional, descriptivo y longitudinal de carácter retrospectivo. Durante los años 2008-2019 se evalúan a todos los pacientes pediátricos sometidos a TPH en nuestro centro que presentan una hipogammaglobulinemia crónica persistente (superior a un año). Se evalúa la fase de tratamiento con inmunoglobulina intravenosa (Privigen®) y los primeros 4 años de tratamiento con inmunoglobulina subcutánea (Hizentra®) mediante un cuestionario. Resultados: Durante los años 2008-2019 se han realizado en nuestro centro 175 trasplantes de precursores hematopoyéticos, de los cuáles 143 (82%) superaron los 3 meses postrasplante. De estos, 3 (2%) pacientes presentaron una hipogammaglobulinemia persistente. Los 3 comparten factores descritos en la bibliografía involucrados en la reconstitución inmune. Mediante el cuestionario se observa que el cambio de gammaglobulina intravenosa a subcutánea ha supuesto una gran mejoría en la calidad de vida de los pacientes. (AU)

Introduction: Hypogammaglobulinemia in the first months after allogeneic hematopoietic stem cell transplantation (HSCT) is common in pediatric patients. During this phase, replacement therapy with human immunoglobulin must be administered parenterally to prevent infections. In some cases, this hypogammaglobulinemia persists over time, which forces further treatment when the patient is usually no longer a carrier of a central line, making them ideal candidates for subcutaneous replacement therapy. There is little published literature describing the use of this method in pediatric patients undergoing HSCT, widely described in replacement treatment in children with primary immunodeficiencies with very good results. Patients and methods: An observational, descriptive, longitudinal and retrospective study is carried out. During the years 2008–2019, we evaluated all pediatric patients undergoing HSCT in our center with persistent chronic hypogammaglobulinemia (for over a year). The treatment phase with intravenous immunoglobulin (Privigen®) and the first four years of treatment with subcutaneous immunoglobulin (Hizentra®) are evaluated using a questionnaire. Results: During the years 2008-2019, 175 patients underwent HSCT, 143 (82%) of whom exceeded three months after transplantation. 3 (2%) of them had persistent hypogammaglobulinemia. All three share factors described in the literature involved in immune reconstitution. After analyzing the questionnaire, it is observed that switching from intravenous to subcutaneous gammaglobulin has involved a great improvement in their quality of life. (AU)

Chronic hypogammaglobulinemia after allogeneic stem cell transplantation and their treatment with subcutaneous immunoglobulin in pediatric patients.

INTRODUCTION: Hypogammaglobulinemia in the first months after allogeneic hematopoietic stem cell transplantation (HSCT) is common in paediatric patients. During this phase, replacement therapy with human immunoglobulin must be administered parenterally to prevent infections. In some cases, this hypogammaglobulinemia persists over time, which forces further treatment when the patient is usually no longer a carrier of a central line, making them ideal candidates for subcutaneous replacement therapy. There is little published literature describing the use of this method in paediatric patients undergoing HSCT, widely described in replacement treatment in children with primary immunodeficiencies with very good results. PATIENTS AND METHODS: An observational, descriptive, longitudinal and retrospective study is carried out. During the years 2008-2019, we evaluated all paediatric patients undergoing HSCT in our center with persistent chronic hypogammaglobulinemia (for over a year). The treatment phase with intravenous immunoglobulin (Privigen®) and the first four years of treatment with subcutaneous immunoglobulin (Hizentra®) are evaluated using a questionnaire. RESULTS: During the years 2008-2019, 175 patients underwent HSCT, 143 (82%) of whom exceeded three months after transplantation. Three (2%) of them had persistent hypogammaglobulinemia. All three share factors described in the literature involved in immune reconstitution. After analysing the questionnaire, it is observed that switching from intravenous to subcutaneous gammaglobulin has involved a great improvement in their quality of life. CONCLUSIONS: The origin of chronic hypogammaglobulinemia in our patients shows different factors and cannot be attributed to a single cause. Due to the limited number of patients no conclusions can be drawn at the population level. We have been able to observe that replacement treatment with Hizentra 20% has been as effective as the intravenous administration without evidence of an increase in bacterial infections. Furthermore, it has also led to an improvement in quality of life and increased comfort, as the patients themselves have stated.

Subcutaneous immunoglobulins in chronic lymphocytic leukemia with secondary antibody deficiency. A monocentric experience during Covid-19 pandemics.

Secondary antibody deficiency (SAD) is a frequent manifestation of chronic lymphocytic leukemia (CLL) that increases the risk of infections. However, no formal guideline are available regarding the eligibility for prophylaxis or the delivery method, dosage, frequency of administration and duration of immunoglobulin replacement therapy (IgRT). The aim of this study was to assess the efficacy and safety of subcutaneous IgRT (SCIg) and its impact on quality of life (QoL) of CLL pts in the Covid-19 era. Ten CLL pts with SAD were treated with subcutaneous IgRT (SCIg) at our institution between October 2019 and December 2020. Median age was 66 years and five patients had comorbidities. Seven patients were receiving therapy for CLL when treatment with SCIg was initiated. All pts received 10 g total dose hyaluronidase-free SCIg independently from body weight. The IgG level and CD4/CD8, CD19 and CD16/56 lymphocytes subset were recorded at baseline and every 3 months. No patient experienced infectious events nor Covid-19 mediated interstitial pneumonia while on SCIg therapy. All patients tolerated well the therapy and experienced an increase of IgG levels, which was then stable in time. We conclude that SCIg administration in CLL pts with SAD is efficacious and safe as infectious prophylaxis. This route of administration appears particularly advantageous in the Covid-19 era, because of the self-administration at home which results in improvement in the QoL and reduced treatment expenditures.

Update on therapy of chronic immune-mediated neuropathies.

Chronic immune-mediated neuropathies, including chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), neuropathies associated with monoclonal gammopathy, and multifocal motor neuropathy (MMN), are a group of disorders deemed to be caused by an immune response against peripheral nerve antigens. Several immune therapies have been reported to be variably effective in these neuropathies including steroids, plasma exchange, and high-dose intravenous (IVIg) or subcutaneous (SCIg) immunoglobulins. These therapies are however far from being invariably effective and may be associated with a number of side effects leading to the use of immunosuppressive agents whose efficacy has not been so far confirmed in randomized trials. More recently, new biological agents, such as rituximab, have proved to be effective in patients with neuropathy associated with IgM monoclonal gammopathy and are currently tested in CIDP.

Prevalence of hypogammaglobulinemia and its management with subcutaneous immunoglobulin supplementation in patients after allogeneic hematopoietic stem cell transplantation-a 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.

Maintenance treatment with subcutaneous immunoglobulins in the long-term management of anti-HMCGR myopathy.

We describe the clinical response to long-term subcutaneous immunoglobulins (SCIg) in anti-3­hydroxy-3-methyl-glutaryl-coenzyme-A-reductase (anti-HMCGR) myopathy previously treated with intravenous immunoglobulins (IVIg). We collected data from patients affected by anti-HMGCR myopathy, switched from IVIg to SCIg therapy, after achieving clinical stabilization. The Medical Research Council sum score, creatine kinase (CK) levels, and anti-HMGCR antibodies were used to assess the response. We identified three patients with anti-HMGCR myopathy treated with SCIg with a favourable clinical course, allowing the maintenance of clinical stability, the reduction or suspension of steroids therapy and in two of them a complete CK normalization. Finally, anti-HMGCR antibodies tested in all patients after 12 months from SCIg starting, showed a global decrease. SCIg represent an useful alternative to long-term IVIg as already well known in several autoimmune neuromuscular disorders and inflammatory myopathies with advantages of lower side effects and home self-administration.

The Development of a New Questionnaire to Measure the Burden of Immunoglobulin Treatment in Patients with Primary Immunodeficiencies: The IgBoT-35.

PURPOSE: To describe the development and psychometric testing of a new questionnaire to measure the burden of immunoglobulin treatment (Ig) from the perspective of patients with primary immunodeficiencies (PID). PATIENTS AND METHODS: An online, cross-sectional survey was administered to PID patients across 10 countries (nine European and Canada) who were receiving either intravenous (IVIg) or subcutaneous (SCIg) immunoglobulin therapy. The range and distribution of the responses (ie, levels of missing data, floor and ceiling effects), exploratory factor analysis (using factor loadings of 0.4 or greater) and measures of internal consistency reliability (ie, Cronbach's alpha coefficient, inter-item and item-total correlations) were used to identify the domain and item pool. RESULTS: In total, 472 patients completed the questionnaire, of which 395 were included in the analysis (32% underwent IVIg and 67% underwent SCIg). The final instrument contained 34 items across eight domains of treatment burden (time, organisation and planning, leisure and social, interpersonal relationships, employment and education, travel, consequences of treatment and emotional) and an additional Ig treatment burden global question at the end of the measure. All the scales achieved good internal reliability (Cronbach's alpha coefficient ranged from 0.70 to 0.85) and, with the exception of one item exceeded the minimum threshold of 0.35 for item-total correlations. Treatment burden was lower than anticipated across the different treatment routes and countries, although overall was more burdensome for patients undergoing IVIg compared to SCIg treatment. CONCLUSION: The IgBoT-35 appears to be a reliable, patient-generated questionnaire and may help to identify more individualised and preferred therapies for the PID patient when used in clinical practice. A new survey with a sample of US patients is currently being undertaken to further establish its validity and conceptual model. The overall Ig burden of treatment scores appeared to be low. PID patient preferences are important to guide treatment decisions and ensuring patients receive the right treatment at the right time.

Long-term efficacy of immunoglobulins in small fiber neuropathy related to Sjögren's syndrome.

The most common peripheral nervous system manifestations in Sjogren's syndrome are small fiber sensory neuropathies (SFPN) and axonal sensorimotor polyneuropathies. Currently, treatment in small fiber neuropathy is mainly symptomatic and based on anti-depressors and anti-epileptics. The benefit of treatment with polyvalent immunoglobulins for SFPN has been reported in small series of patients, although transient in several cases. The medium-to-long-term effects of polyvalent immunoglobulins (Ig) in SFPN in patients with Sjogren's syndrome who are refractory to conventional treatments remain an unmet medical need. We present our experience related to the persistent improvement of Ig in a case series of SFPN in Sjogren's syndrome and relevant data in the literature regarding the benefits of immunoglobulins, for this indication.

Long-term efficacy, safety, and tolerability of recombinant human hyaluronidase-facilitated subcutaneous infusion of immunoglobulin (Ig) (fSCIG; HyQvia(®)) in immunodeficiency diseases: real-life data from a monocentric experience.

Humoral immunodeficiency diseases represent a heterogeneous group of disorders that require long-term therapies. Thus, the treatment provided must not only be effective but also safe and well tolerated. In this paper, we report our data on the efficacy, safety, and tolerability of recombinant human hyaluronidase-facilitated subcutaneous infusion of immunoglobulin (Ig) (fSCIG; HyQvia(®)) in immunodeficiency patients. We collected retrospective data from 30 patients with primary and secondary immunodeficiency diseases in therapy with fSCIG from September 2014 to December 2019. We evaluated the efficacy of the therapy, taking into account serum IgG values during follow-up and the number of annual infectious events and serious bacterial infections reported by patients. Safety was assessed on the basis of the number and intensity of adverse events (AEs) and local reactions reported. Our real-life data suggest that long-term repeated self-administration of recombinant human hyaluronidase-facilitated subcutaneous infusion of immunoglobulins results in a reduced rate of infectious events if compared to the pre-treatment rate. Both AEs and local reactions are mild to moderate and were never reasons for treatment discontinuation. Therapy with HyQvia shows prolonged efficacy and good tolerability; these aspects, together with the possibility of self-administration at home, minimize the impact the illness has on patients.

Sustained response to subcutaneous immunoglobulins in chronic ataxic neuropathy with anti-disialosyl IgM antibodies (CANDA): report of two cases and review of the literature.

INTRODUCTION: Chronic ataxic neuropathy with anti-disialosyl IgM antibodies (CANDA) is a rare disorder for which the pathological, neurophysiological, and therapeutic evidence remains anecdotal and controversial. METHODS: This report on CANDA focuses on the neurophysiological patterns and treatment responses shared by two cases. One patient underwent nerve ultrasound follow-up. A comprehensive review of the literature highlighted the diverse experiences with different treatment options. RESULTS: Response to different therapies was similar in both patients: intravenous immunoglobulins achieved a favorable response albeit with significant wearing-off fluctuations; treatment with subcutaneous immunoglobulins (SCIg) was an effective alternative leading to a clinical response for at least 2 years. Rituximab, which was trialed in both patients, was not continued long enough to determine its efficacy in modifying the disease course and/or modulating responsiveness to immunoglobulins. Steroids caused clinical worsening in both patients. CONCLUSIONS: Immunoglobulin therapy appeared as the most effective in the treatment of these two patients. SCIg provided an effective treatment option for the long-term management of CANDA.

Prevention of parvovirus B19-induced repetitive acute kidney failure by subcutaneous immunoglobulins.

Human parvovirus B19 has been associated with various cases of kidney injuries with different glomerular phenotypes. In immunocompromised individuals, insufficient production of neutralizing antibodies can lead to chronic PVB19 carriage and manifestations. However, PVB19 DNA has been detected in bone marrow and peripheral blood for months or years in seemingly immunocompetent individuals, despite the presence of neutralizing antibodies. We report here PVB19-induced recurrent anuric acute kidney failures in a 57-year-old man over a 7-year period with persistent PVB19 infection and then PVB19-associated cryoglobulinemia. Acute renal failures were preceded by influenza-like syndrome associated with arthralgia, skin rash, and low-grade fever. Serum, bone marrow, renal, and digestive PVB19 replication was found in the different episodes. Endocapillary proliferative glomerulonephritis evolved into membranoproliferative glomerulonephritis. Complete renal recovery occurred after each bout. Off-label subcutaneous immunoglobulin therapy resulted in disappearance of blood and bone marrow PVB19 viral load and stopped the glomerulonephritis recurrence. Subcutaneous immunoglobulin therapy withdrawal resulted in renal relapse with cryoglobulin-associated manifestations.

Efficacy and Tolerability of Intravenous Immunoglobulin and Subcutaneous Immunoglobulin in Neurologic Diseases.

PURPOSE: IV immunoglobulin (Ig) therapy has been widely used for the treatment of neurologic disorders, autoimmune diseases, immunodeficiency-related diseases, blood system diseases, and cancers. In this review, we summarize the efficacy and tolerability of IVIg and SCIg therapy in neurologic diseases. METHODS: We summarized and analyzed the efficacy and tolerability of IVIg and SCIg in neurologic diseases, by analyzing the literature pertaining to the use of IVIg and SCIg to treat nervous system diseases. FINDINGS: In clinical neurology practice, IVIg has been shown to be useful for the treatment of new-onset or recurrent immune diseases and for long-term maintenance treatment of chronic diseases. Moreover, IVIg may have applications in the management of intractable autoimmune epilepsy, paraneoplastic syndrome, autoimmune encephalitis, and neuromyelitis optica. SCIg is emerging as an alternative to IVIg treatment. Although SCIg has a composition similar to that of IVIg, the applications of this therapy are different. Notably, the bioavailability of SCIg is lower than that of IVIg, but the homeostasis level is more stable. Current studies have shown that these 2 therapies have pharmacodynamic equivalence. IMPLICATIONS: In this review, we explored the efficacy of IVIg in the treatment of various neurologic disorders. IVIg administration still faces many challenges. Thus, it will be necessary to standardize the use of IVIg in the clinical setting. SCIg administration is a novel and feasible treatment option for neurologic and immune-related diseases, such as chronic inflammatory demyelinating polyradiculoneuropathy and idiopathic inflammatory myopathies. As our understanding of the mechanisms of action of IVIg improve, potential next-generation biologics can being developed.

Subcutaneous Immunoglobulin in Infantile Chronic Inflammatory Demyelinating Polyneuropathy: A Case Report.

Chronic inflammatory demyelinating polyneuropathy (CIDP) is a chronically progressive or relapsing sensorimotor disorder presumably due to antibody-mediated reactions. It is a rare condition in children, with estimated prevalence as 0.48 per 100,000 among patients younger than 20 years of age. Recommended treatments include immune modulators, intravenous immunoglobulins (IVIgs), steroids, and plasmapheresis. Management of pediatric CIDP is challenging because of the lack of evidence-based efficacy of the current therapies in children. Because of the rarity of this condition, there are no double-blind randomized studies to support the therapeutic choice as well as to identify the optimal first-line therapeutic regimen. IVIgs are widely used but the intravenous administration is usually uncomfortable, especially for children. Subcutaneous immunoglobulins (SCIgs) have proven to be effective in adults with CIDP and in children affected by antibody deficiencies and other different immune and inflammatory disorders. Herein, we described the case of a 7-year-old boy, affected by CIDP who clinically responded to IVIg but was dependent on this therapy. In order to improve his quality of life, we switched to SCIg with excellent result.

Adverse effects of immunoglobulin therapy.

Immunoglobulin products contain specific antibodies in IgG class which are directed against wide range of pathogens. These products are obtained from plasma of healthy donors. Immunoglobulin derivates can be administrated by intravenous or subcutaneous route in substitution or immunomodulation indications. The administration can be accompanied by a risk of adverse events. The most common are pyretic reactions, chills, headache, nausea, malaise and muscle pain, nevertheless also severe systemic reactions can occur. Almost one third of the reactions appear during the first administration. The number and severity of reactions depends on administered dose, speed and the application way. Pre-existing comorbidities of the patients and presence of acute infection are also an important risk factors for adverse reactions. Therapy of side effects is mostly symptomatic.

Passive blood anaphylaxis: subcutaneous immunoglobulins are a cause of ongoing passive anaphylactic reaction.

BACKGROUND: Allergic, especially anaphylactic, reactions during immunoglobulin replacement therapy are rare, but their pathophysiology and classification remain ambiguous. Recent findings show positive results of skin tests with commercially available immunoglobulins, but target antigens and responsible compounds of the tested immunoglobulins have not been strictly identified. CASE DESCRIPTION AND FINDINGS: Four adult patients with recently diagnosed common variable immunodeficiency qualified for standard subcutaneous immunoglobulin replacement therapy regimen. They had no history of receiving immunoglobulins, blood or blood product transfusions. Edema, confluent wheals and erythema were observed at the site of subcutaneous immunoglobulin infusion: typical early and late phase reaction. A transient increase in various passively transferred IgG and IgE antibodies was responsible for misleading positive outcome of the serological testing for active humoral response such as type I allergy, anti-Rh, isohemagglutinins and rheumatoid factor (RF). Although the clinical presentation was very unusual and severe, the retrospective analysis showed no isohemagglutinins, RF and IgE in the patients' serum before but it was positive after the infusion (median IgE = 18 IU/ml, RF = 8 IU/ml). Type I allergic reaction (laryngeal edema, rhinoconjuctivitis) came out at +14 days of replacement therapy when the patient visited countryside. In the second patient anaphylactic reaction was observed 5 days after ScIg administration, and only when the patient consumed peanuts. Therefore, IgE concentration was measured retrospectively in a series of commercial preparations used in the initial subcutaneous immunoglobulin replacement therapy that caused the adverse event (AE) and it was determined between 138 and 232 IU/ml (kU/l), i.e. 690-2100 IU per g of protein. Specific IgE was within a wide range from 198 (mix of food) to 2809 kUA/l (mix of grass) but many of the tested allergen-specific IgE were class 2 or 3 (i.e. 0.71-17.5 kUA/l). CONCLUSIONS: The case resembles passive cutaneous anaphylaxis and Prausnitz-Küstner reaction but clinical significance of the classical phenomena has not yet been described. This observation indicates that anaphylactic reactions during immunoglobulin replacement therapy may result from IgE or pathological IgG content. Such IgE presence was sporadically reported (34.5-105 IU/ml, i.e. 862.5-1450 IU/g of protein) in intravenous immunoglobulins that are used and monitored by healthcare professionals. In clinical practice the definition of adverse events is inadequate since individual batches of immunoglobulins come with different specificity therefore, they should be classified as transfusion products (not bioequivalents). Such new approach implies establishing (1) new control methods and strategies to ensure introduction of the safety regulations for subcutaneous home self-administration of immunoglobulins as well as (2) guidelines for the prevention of anaphylaxis in patients receiving immunoglobulins (for example peanut).

Shift from intravenous or 16% subcutaneous replacement therapy to 20% subcutaneous immunoglobulin in patients with primary antibody deficiencies.

In patients with primary antibody deficiencies, subcutaneous administration of IgG (SCIG) replacement is effective, safe, well-tolerated, and can be self-administered at home. A new SCIG replacement at 20% concentration (Hizentra®) has been developed and has replaced Vivaglobin® (SCIG 16%). An observational prospective multi-centric open-label study, with retrospective comparison was conducted in 15 Italian centers, in order to investigate whether and to what extent switching to Hizentra® would affect frequency of infusions, number of infusion sites, patients' satisfaction, and tolerability in patients previously treated with Vivaglobin® or intravenous immunoglobulins (IVIG). Any variations of dosage, frequency and duration of the infusions, and of number of infusion sites induced by Hizentra® with respect to the former treatment were recorded. Practical advantages and disadvantages of Hizentra®, with respect to the medicinal product formerly used, and the variations in patients' therapy-related satisfaction were monitored by means of the TSQM (Treatment Satisfaction Questionnaire for Medication); number, frequency, and duration of infectious events and adverse effects were recorded. Eighty-two patients switched to Hizentra®: 19 (23.2%) from IVIG and 63 (76.8%) from Vivaglobin®. The mean interval between infusions was not affected by the shift (7.0 ± 2.0 days with previous treatment versus 7.1 ± 1.2 during Hizentra®). A decrease in the number of infusion sites with Hizentra® was recorded in 12 out of 56 patients for whom these data were available. At 6 months, 89.7% of patients were satisfied with Hizentra®; no difference in terms of effectiveness, side effects, convenience, and global satisfaction was observed. No difference in the incidence of adverse events was reported.