Comparison of American and European practices in the management of patients with primary immunodeficiencies

Barriers and facilitators to the implementation of guidelines in rare diseases: a systematic review

BACKGROUND

Rare diseases present a challenge to guideline implementation due to a low prevalence in the general population and the unfamiliarity of healthcare professionals. Existing literature in more common diseases references barriers and facilitators to guideline implementation. This systematic review aims to identify these barriers and facilitators in rare diseases from existing literature.

METHODS

A multi-stage strategy included searching MEDLINE PubMed, EMBASE Ovid, Web of Science and Cochrane library from the earliest date available to April 2021, Orphanet journal hand-search, a pearl-growing strategy from a primary source and reference/citation search was performed. The Integrated Checklist of Determinants of Practice which comprises of twelve checklists and taxonomies, informed by 57 potential determinants was selected as a screening tool to identify determinants that warrant further in-depth investigation to inform design of future implementation strategies.

RESULTS

Forty-four studies were included, most of which were conducted in the United States (54.5%). There were 168 barriers across 36 determinants (37 studies) and 52 facilitators across 22 determinants (22 studies). Fifteen diseases were included across eight WHO ICD-11 disease categories. Together individual health professional factors and guideline factors formed the majority of the reported determinants (59.5% of barriers and 53.8% of facilitators). Overall, the three most reported individual barriers were the awareness/familiarity with the recommendation, domain knowledge and feasibility. The three most reported individual facilitators were awareness/familiarity with the recommendation, agreement with the recommendation and ability to readily access the guidelines. Resource barriers to implementation included technology costs, ancillary staff costs and more cost-effective alternatives. There was a paucity of studies reporting influential people, patient advocacy groups or opinion leaders, or organisational factors influencing implementation.

CONCLUSIONS

Key barriers and facilitators to the implementation of clinical practice guidelines in the setting of rare diseases were at the individual health professional and guideline level. Influential people and organisational factors were relatively under-reported and warrant exploration, as does increasing the ability to access the guidelines as a potential intervention.

Immunoglobulin treatment for B-cell immunodeficiencies

This article aims to describe the rationale and utility of immunoglobulin therapies in patients with B-cell immunodeficiency states. We describe the historical perspective, mechanism of actions, and indications for use in this population. We then focus upon management pearls and special considerations for its utility. Finally, we elaborate upon the important economic implications for these patients and the need to develop individualized management strategies in this vulnerable population.

Respiratory Infections in Patients with Primary Immunodeficiency

Recurrent and life-threatening respiratory infections are nearly universal in patients with primary immunodeficiency diseases (PIDD). Early recognition, aggressive treatment, and prophylaxis with antimicrobials and immunoglobulin replacement have been the mainstays of management and will be reviewed here with an emphasis on respiratory infections. Genetic discoveries have allowed direct translation of research to clinical practice, improving our understanding of clinical patterns of pathogen susceptibilities and guiding prophylaxis. The recent identification of inborn errors in type I interferon signaling as a basis for life-threatening viral infections in otherwise healthy individuals suggests another targetable pathway for treatment and/or prophylaxis. The future of PIDD diagnosis will certainly involve early genetic identification by newborn screening before onset of infections, with early treatment offering the potential of preventing disease complications such as chronic lung changes. Gene editing approaches offer tremendous therapeutic potential, with rapidly emerging delivery systems. Antiviral therapies are desperately needed, and specific cellular therapies show promise in patients requiring hematopoietic stem cell transplantation. The introduction of approved therapies for clinical use in PIDD is limited by the difficulty of studying outcomes in rare patients/conditions with conventional clinical trials.

A summertime pause in immunoglobulin replacement therapy: a prospective real-world analysis

Aim: To describe the effects of a summertime pause (SP) in immunoglobulin replacement therapy (IgRT). Patients & methods: We conducted a prospective single-center observational study, including 44 patients undergoing intravenous IgRT between May and June 2019 in a French teaching hospital. Results: IgRT was interrupted in 23 patients from June to October. Patients who underwent an SP were older, more likely to have secondary immunodeficiency (SID) and received lower doses of immunoglobulin and more antibiotics during winter. Most patients who did not undergo an SP had severe primary immunodeficiency. The SP did not increase the risk of infection, improved the quality of life and reduced treatment costs. Conclusion: SP in IgRT is a safe practice and should be considered for patients with mild SID.

Global systematic review of primary immunodeficiency registries

INTRODUCTION

During the last 4 decades, registration of patients with primary immunodeficiencies (PID) has played an essential role in different aspects of these diseases worldwide including epidemiological indexes, policymaking, quality controls of care/life, facilitation of genetic studies and clinical trials as well as improving our understanding about the natural history of the disease and the immune system function. However, due to the limitation of sustainable resources supporting these registries, inconsistency in diagnostic criteria and lack of molecular diagnosis as well as difficulties in the documentation and designing any universal platform, the global perspective of these diseases remains unclear.

AREAS COVERED

Published and unpublished studies from January 1981 to June 2020 were systematically reviewed on PubMed, Web of Science and Scopus. Additionally, the reference list of all studies was hand-searched for additional studies. This effort identified a total of 104614 registered patients and suggests identification of at least 10590 additional PID patients, mainly from countries located in Asia and Africa. Molecular defects in genes known to cause PID were identified and reported in 13852 (13.2% of all registered) patients.

EXPERT OPINION

Although these data suggest some progress in the identification and documentation of PID patients worldwide, achieving the basic requirement for the global PID burden estimation and registration of undiagnosed patients will require more reinforcement of the progress, involving both improved diagnostic facilities and neonatal screening.

Recommendations for screening, monitoring, prevention, and prophylaxis of infections in adult and pediatric patients receiving CAR T-cell therapy: a position paper

Chimeric antigen receptor (CAR) T-cell therapy is one of the most promising emerging treatments for B-cell malignancies. Recently, two CAR T-cell products (axicabtagene ciloleucel and tisagenlecleucel) have been approved for patients with aggressive B-cell lymphoma and acute lymphoblastic leukemia; many other CAR-T constructs are in research for both hematological and non-hematological diseases. Most of the patients receiving CAR-T therapy will develop fever at some point after infusion, mainly due to cytokine release syndrome (CRS). The onset of CRS is often indistinguishable from an infection, which makes management of these patients challenging. In addition to the lymphodepleting chemotherapy and CAR T cells, the treatment of complications with corticosteroids and/or tocilizumab increases the risk of infection in these patients. Data regarding incidence, risk factors and prevention of infections in patients receiving CAR-T cell therapy are scarce. To assist in patient care, a multidisciplinary team from hospitals designated by the Spanish Ministry of Health to perform CAR-T therapy prepared these recommendations. We reviewed the literature on the incidence, risk factors, and management of infections in adult and pediatric patients receiving CAR-T cell treatment. Recommendations cover different areas: monitoring and treatment of hypogammaglobulinemia, prevention, prophylaxis, and management of bacterial, viral, and fungal infections as well as vaccination prior and after CAR-T cell therapy.

Treatment and management of primary antibody deficiency: German interdisciplinary evidence-based consensus guideline

This evidence-based clinical guideline provides consensus-recommendations for the treatment and care of patients with primary antibody deficiencies (PADs). The guideline group comprised 20 clinical and scientific expert associations of the German, Swiss, and Austrian healthcare system and representatives of patients. Recommendations were based on results of a systematic literature search, data extraction, and evaluation of methodology and study quality in combination with the clinical expertise of the respective representatives. Consensus-based recommendations were determined via nominal group technique. PADs are the largest clinically relevant group of primary immunodeficiencies. Most patients with PADs present with increased susceptibility to infections, however immune dysregulation, autoimmunity, and cancer affect a significant number of patients and may precede infections. This guideline therefore covers interdisciplinary clinical and therapeutic aspects of infectious (e.g., antibiotic prophylaxis, management of bronchiectasis) and non-infectious manifestations (e.g., management of granulomatous disease, immune cytopenia). PADs are grouped into disease entities with definitive, probable, possible, or unlikely benefit of IgG-replacement therapy. Summary and consensus-recommendations are provided for treatment indication, dosing, routes of administration, and adverse events of IgG-replacement therapy. Special aspects of concomitant impaired T-cell function are highlighted as well as clinical data on selected monogenetic inborn errors of immunity formerly classified into PADs (APDS, CTLA-4-, and LRBA-deficiency).

Effect of an awareness campaign on the diagnosis and clinical impact of primary immunodeficiency

BACKGROUND AND OBJECTIVES

Predominantly antibody deficiencies are the most prevalent primary immunodeficiency (PID) in adults. These are rare diseases difficult to diagnose. Therefore, they are diagnosed late. This study aims to evaluate whether an awareness campaign of PIDs among physicians is associated with an increase in number of diagnoses, a reduction in diagnostic delay and diagnosis at earlier stages.

PATIENTS AND METHODS

A single centre, interventional, quasi-experimental study was designed that included 2 periods, period 1 pre-intervention (1986-2008) and period 2 post-intervention (2009-2018). A descriptive comparative study of variables was carried out in both periods.

RESULTS

116 patients were included [27 (23.3%) in period 1 and 89 (76.7%) in period 2]. The incidence rate increased significantly (0.204 and 1.236/100,000habs./year; P < 0.05), the diagnosis delay tended to be lower (4 vs. 3.73 years). The reasons for diagnostic suspicion were diverse and the burden disease at diagnosis (expressed by bronchiectasis, altered spirometry, ability to generate antibodies by thymus-independent mechanism and need for substitute treatment) tended to decrease in period 2.

CONCLUSIONS

Given the potentially serious complications of patients with late diagnosis of PIDs, it is necessary to create specialized multidisciplinary units, to unify assistance protocols and to design interventions to increase the knowledge of these entities.

Diagnosis and management of Specific Antibody Deficiency

Specific antibody deficiency is a primary immunodeficiency disease recognized by the International Union of Immunology Societies and defined by recurrent respiratory infections with normal immunoglobulins, but diminished antibody responses to polysaccharide antigens after vaccination with the 23 valent pneumococcal polysaccharide vaccine. Clinical immunologists struggle with diagnosis and treatment, because the definition of an adequate response to immunization remains controversial. Specific antibody deficiency is managed clinically with close follow-up and prompt treatment of infections, antibiotic prophylaxis, or immune globulin therapy. Treatment is individualized using clinical judgment and existing practice guidelines, which will likely evolve as more studies become available.

A Study of Tolerability, Satisfaction, and Cost Reduction Using a 10% Immunoglobulin Product at Higher Administration Rates

Gammaplex 10% (immune globulin intravenous [human], Bio Products Laboratory, Ltd) can be administered with a 15-minute rate-escalation protocol. This analysis examined safety, patient satisfaction, and cost savings in 49 patients administered Gammaplex 10% via rapid infusion over 11 months. Fourteen patients reported 38 adverse reactions, 37 of which were deemed minor/moderate. Patient satisfaction was very good/outstanding. Infusions were estimated to be 2.4 hours shorter than previously administered intravenous immunoglobulin infusions, saving $151.61 per visit in nursing costs. Rapid infusion of Gammaplex 10% was found to be a safe option to reduce the costs of intravenous immunoglobulin treatment while maintaining patient satisfaction.

Impact of IVIG vs. SCIG on IgG trough level and infection incidence in primary immunodeficiency diseases: A systematic review and meta-analysis of clinical studies

Background

Monthly intravenous immunoglobulin (IVIG) and weekly subcutaneous immunoglobulin (SCIG) have been regarded as therapeutically equivalent treatments for primary immunodeficiency diseases (PIDD). Immunoglobulin G (IgG) trough level is used as a monitoring measure for infection prevention.

Objective

A systematic review and meta-analysis were performed to elucidate the relationship between IgG dosing, trough IgG levels with overall infection incidence in patients with PIDD receiving IVIG and SCIG therapy.

Methods

Medline, EMBASE, Cochrane, Central, and Scopus were searched for studies published from Jan 2010-June 2018, fulfilling the inclusion criteria. DerSimonian and Laird random-effects method were used to pool the difference of IgG trough levels. Random-effect meta-regression was used to evaluate infection incidence per 100 mg/dl IgG trough increase though IVIG and SCIG.

Results

Out of 24 observational studies included, 11 compared IgG trough levels among SCIG and IVIG (mean difference: 73.4 mg/dl, 95% CI: 31.67-119.19 mg/dl, I2 = 45%, p = 0.05), favoring weekly SCIG. For every 100 mg/dl increase in the trough, a linear trend of decreased incidence rates of infection was identified in SCIG patients (p = 0.03), but no similar trend was identified in trough levels vs. infection rates for patients receiving IVIG (p = 0.67).

Conclusion

In our study, weekly SCIG attained a higher trough level in comparison to monthly IVIG. Higher SCIG troughs were associated with lower infection rates, while IVIG troughs demonstrated no relationship.

Clinical Efficacy, Safety and Tolerability of a New Subcutaneous Immunoglobulin 16.5% (Octanorm [Cutaquig®]) in the Treatment of Patients With Primary Immunodeficiencies

Introduction: Subcutaneously administered immunoglobulin (SCIG) is increasingly used to treat patients with primary immunodeficiencies (PIDs). Octanorm (marketed as cutaquig® in USA and Canada) is a new 16.5% solution of human SCIG, manufactured by a process based on that of the intravenous preparation (IVIG) octagam®. Objectives: To investigate the efficacy, safety and tolerability of octanorm in a prospective, open-label, single-arm phase 3 study involving adult and pediatric patients with PIDs (NCT01888484; clinicaltrials.gov/ct2/show/NCT01888484). Methods: Patients who were previously treated with IVIG received a total of 64 weekly SCIG infusions, including 12 weekly infusions during the wash-in/wash-out period, followed by 52 weekly infusions during the evaluation period. Results: A total of 61 patients aged 2-73 years received 3,497 infusions of octanorm. The mean dose per patient was 0.175 g/kg/infusion. The mean calculated dose conversion factor from the patients' previous IVIG dose for octanorm was 1.37. No serious bacterial infections developed during the study. The rate of other infections per person-year during the primary observation period was 3.43 (upper 95% CI 4.57). All but one non-bacterial infection were mild or moderate in intensity. IgG trough levels were constant during the course of the study. Eleven patients (18.0%) experienced 14 mild or moderate systemic adverse events (AEs) related to octanorm. The rate of related AEs per infusion was 0.004. In 76.7% of infusions, no infusion site reactions were observed and only two (0.3%) reactions were deemed severe. The incidence of site reactions decreased with successive infusions. Conclusion: The new 16.5% SCIG octanorm was shown to be efficacious in preventing infections in PIDs, and was well tolerated.

Latent therapeutic demand model for the immunoglobulin replacement therapy of primary immune deficiency disorders in the USA

BACKGROUND AND OBJECTIVES

Our research aim is to model latent therapeutic demand (LTD) for the immunoglobulin replacement therapy (IgGRT) of primary immune deficiency disorders (PIDDs) in the USA. Given the high level of variability of IgGRT use and major differences among American and European practices in the management of patients with PIDDs, we develop a USA-specific LTD model for common variable immune deficiency (CVID), hyper IGM syndrome, severe combined immune deficiency, Wiskott-Aldrich syndrome and X-linked agammaglobulinemia (XLA).

METHODS AND MATERIALS

We use decision analysis methods to model the underlying IgGRT demand for PIDDs by assessing USA-specific epidemiology and treatment. Data for the epidemiology and treatment variables were obtained from the medical literature, USIDNET and Immune Deficiency Foundation. The uncertainty surrounding the variables was modelled using probability distributions and evaluated using Monte Carlo simulation.

RESULTS

The mean treatment dose from USIDNET and European Society for Immunodeficiencies (ESID) was significantly different for treating CVID, and the number of annual infusions from USIDNET and ESID was significantly different for treating CVID and XLA. The mean and standard deviation of LTD for all PIDDs is 105·1 ± 88·5 g per 1000 population, with CVID contributing the most to LTD.

CONCLUSION

Estimating country-specific LTD is important to ensure an adequate supply of IgGRT and an optimal treatment for patients with PIDDs and for improving national healthcare policymaking and production planning.

II Brazilian Consensus on the use of human immunoglobulin in patients with primary immunodeficiencies

In the last few years, new primary immunodeficiencies and genetic defects have been described. Recently, immunoglobulin products with improved compositions and for subcutaneous use have become available in Brazil. In order to guide physicians on the use of human immunoglobulin to treat primary immunodeficiencies, based on a narrative literature review and their professional experience, the members of the Primary Immunodeficiency Group of the Brazilian Society of Allergy and Immunology prepared an updated document of the 1^st Brazilian Consensus, published in 2010. The document presents new knowledge about the indications and efficacy of immunoglobulin therapy in primary immunodeficiencies, relevant production-related aspects, mode of use (routes of administration, pharmacokinetics, doses and intervals), adverse events (major, prevention, treatment and reporting), patient monitoring, presentations available and how to have access to this therapeutic resource in Brazil.

Screening protocols to monitor respiratory status in primary immunodeficiency disease: findings from a European survey and subclinical infection working group

Many patients with primary immunodeficiency (PID) who have antibody deficiency develop progressive lung disease due to underlying subclinical infection and inflammation. To understand how these patients are monitored we conducted a retrospective survey based on patient records of 13 PID centres across Europe, regarding the care of 1061 adult and 178 paediatric patients with PID on immunoglobulin (Ig) G replacement. The most common diagnosis was common variable immunodeficiency in adults (75%) and hypogammaglobulinaemia in children (39%). The frequency of clinic visits varied both within and between centres: every 1-12 months for adult patients and every 3-6 months for paediatric patients. Patients diagnosed with lung diseases were more likely to receive pharmaceutical therapies and received a wider range of therapies than patients without lung disease. Variation existed between centres in the frequency with which some clinical and laboratory monitoring tests are performed, including exercise tests, laboratory testing for IgG subclass levels and specific antibodies, and lung function tests such as spirometry. Some tests were carried out more frequently in adults than in children, probably due to difficulties conducting these tests in younger children. The percentage of patients seen regularly by a chest physician, or who had microbiology tests performed following chest and sinus exacerbations, also varied widely between centres. Our survey revealed a great deal of variation across Europe in how frequently patients with PID visit the clinic and how frequently some monitoring tests are carried out. These results highlight the urgent need for consensus guidelines on how to monitor lung complications in PID patients.

A Multicentre Study on the Efficacy, Safety and Pharmacokinetics of IqYmune®, a Highly Purified 10% Liquid Intravenous Immunoglobulin, in Patients with Primary Immune Deficiency

This multicentre, open-label, prospective, single-arm study was designed to evaluate the efficacy, pharmacokinetics, and safety of IqYmune®, a highly purified 10% polyvalent immunoglobulin preparation for intravenous administration in patients with primary immunodeficiency. IqYmune® was administered to 62 patients (aged 2–61 years) with X-linked agammaglobulinemia or common variable immune deficiency at a dose from 0.22 to 0.97 g/kg every 3 to 4 weeks for 12 months with an infusion rate up to 8 mL/kg/h. A pharmacokinetic study was performed at steady state between the 8th and the 9th infusion. A single case of serious bacterial infection was observed, leading to an annualized rate of serious bacterial infections/patient (primary endpoint) of 0.017 (98% CI: 0.000, 0.115). Overall, 228 infections were reported, most frequently bronchitis, chronic sinusitis, nasopharyngitis and upper respiratory tract infection. The mean annualized rate of infections was 3.79/patient. A lower risk of infections was associated with an IgG trough level > 8 g/L (p = 0.01). The mean annualized durations of absence from work or school and of hospitalization due to infections were 1.01 and 0.89 days/patient, respectively. The mean serum IgG trough level before the 6th infusion was 7.73 g/L after a mean dose of IqYmune® of 0.57 g/kg. The pharmacokinetic profile of IqYmune® was consistent with that of other intravenous immunoglobulins. Overall, 15.5% of infusions were associated with an adverse event occurring within 72 h post infusion. Headache was the most common adverse event. In conclusion, IqYmune® was shown to be effective and well tolerated in patients with primary immunodeficiency.

Specific Antibody Deficiency: Controversies in Diagnosis and Management

Specific antibody deficiency (SAD) is a primary immunodeficiency disease characterized by normal immunoglobulins (Igs), IgA, IgM, total IgG, and IgG subclass levels, but with recurrent infection and diminished antibody responses to polysaccharide antigens following vaccination. There is a lack of consensus regarding the diagnosis and treatment of SAD, and its clinical significance is not well understood. Here, we discuss current evidence and challenges regarding the diagnosis and treatment of SAD. SAD is normally diagnosed by determining protective titers in response to the 23-valent pneumococcal polysaccharide vaccine. However, the definition of an adequate response to immunization remains controversial, including the magnitude of response and number of pneumococcal serotypes needed to determine a normal response. Confounding these issues, anti-polysaccharide antibody responses are age- and probably serotype dependent. Therapeutic strategies and options for patients with SAD are often based on clinical experience due to the lack of focused studies and absence of a robust case definition. The mainstay of therapy for patients with SAD is antibiotic prophylaxis. However, there is no consensus regarding the frequency and severity of infections warranting antibiotic prophylaxis and no standardized regimens and no studies of efficacy. Published expert guidelines and opinions have recommended IgG therapy, which are supported by observations from retrospective studies, although definitive data are lacking. In summary, there is currently a lack of evidence regarding the efficacy of therapeutic strategies for patients with SAD. We believe that it is best to approach each patient as an individual and progress through diagnostic and therapeutic interventions together with existing practice guidelines.

Update on the use of immunoglobulin in human disease: A review of evidence

Human immunoglobulin preparations for intravenous or subcutaneous administration are the cornerstone of treatment in patients with primary immunodeficiency diseases affecting the humoral immune system. Intravenous preparations have a number of important uses in the treatment of other diseases in humans as well, some for which acceptable treatment alternatives do not exist. We provide an update of the evidence-based guideline on immunoglobulin therapy, last published in 2006. Given the potential risks and inherent scarcity of human immunoglobulin, careful consideration of its indications and administration is warranted.

Family Physician Perspectives on Primary Immunodeficiency Diseases

Primary immunodeficiency diseases (PIDs) include over 250 diverse disorders. The current study assessed management of PID by family practice physicians. The American Academy of Allergy, Asthma, and Immunology Primary Immunodeficiency Committee and the Immune Deficiency Foundation conducted an incentivized mail survey of family practice physician members of the American Medical Association and the American Osteopathic Association in direct patient care. Responses were compared with subspecialist immunologist responses from a similar survey. Surveys were returned by 528 (of 4500 surveys mailed) family practice physicians, of whom 44% reported following ≥1 patient with PID. Selective immunoglobulin A deficiency (21%) and chronic granulomatous disease (11%) were most common and were followed by significantly more subspecialist immunologists (P < 0.05). Use of intravenously administered immunoglobulin and live viral vaccinations across PID was significantly different (P < 0.05). Few family practice physicians were aware of professional guidelines for diagnosis and management of PID (4 vs. 79% of subspecialist immunologists, P < 0.05). Family practice physicians will likely encounter patients with PID diagnoses during their career. Differences in how family practice physicians and subspecialist immunologists manage patients with PID underscore areas where improved educational and training initiatives may benefit patient care.

The effects of prenatal genetic analysis on fetuses born to carrier mothers with primary immunodeficiency diseases

OBJECTIVE

Prenatal genetic analysis in primary immunodeficiency diseases (PIDs) can decrease morbidity and mortality.

METHODS

We compared the postnatal prognoses of index cases and their subsequent sibling-fetuses using prenatal genetic analysis.

RESULTS

From 2007 to 2014, 14 sibling-fetuses receiving a prenatal diagnosis born to four mothers with WAS, three with X-CGD, and one each with IPEX, XLA and severe combined immunodeficiency [RAG2-SCID] were recruited. There were six affected, two carriers, and six wild types. Among the six affected, four [3X-CGD and 1RAG2-SCID] were terminated and two [1WAS and 1X-CGD] with early prophylactics underwent successful hematopoietic stem cell transplantation (HSCT) without infection. In the 12 index cases with a postnatal diagnosis, eight died (five due to infections and one each due to refractory bleeding, severe diarrhea, and post-transplant pneumothorax), two X-CGD underwent reconstituted HSCT after recurrent life-threatening infections, one WAS developed malignancy, and another WAS developed autoimmune disorders despite the administration of prophylactics and regular immunoglobulin infusion.

CONCLUSION

Instead of recurrent life-threatening infections leading to mortality in the postnatal diagnosis group, the severe PIDs who received early prophylactics were cured by HSCT, and all of mortality were terminations in the prenatal diagnosis group. Further large-scale studies are needed to validate this beneficial effect. Key message Prenatal genetic analysis in fetuses born to PIDs carrier mothers allows for the affected fetuses to receive optimal management including prophylactics against infections and HSCT if indicated. Patients with PIDs diagnosed postnatally who are prone to severe infections have higher rates of morbidity and mortality than their subsequent siblings who have a prenatal genetic diagnosis.

Current treatment options with immunoglobulin G for the individualization of care in patients with primary immunodeficiency disease

Primary antibody deficiencies require lifelong replacement therapy with immunoglobulin (Ig)G to reduce the incidence and severity of infections. Both subcutaneous and intravenous routes of administering IgG can be effective and well tolerated. Treatment regimens can be individualized to provide optimal medical and quality-of-life outcomes in infants, children, adults and elderly people. Frequency, dose, route of administration, home or infusion-centre administration, and the use of self- or health-professional-administered infusion can be tailored to suit individual patient needs and circumstances. Patient education is needed to understand the disease and the importance of continuous therapy. Both the subcutaneous and intravenous routes have advantages and disadvantages, which should be considered in selecting each patient's treatment regimen. The subcutaneous route is attractive to many patients because of a reduced incidence of systemic adverse events, flexibility in scheduling and its comparative ease of administration, at home or in a clinic. Self-infusion regimens, however, require independence and self-reliance, good compliance on the part of the patient/parent and the confidence of the physician and the nurse. Intravenous administration in a clinic setting may be more appropriate in patients with reduced manual dexterity, reluctance to self-administer or a lack of self-reliance, and intravenous administration at home for those with good venous access who prefer less frequent treatments. Both therapy approaches have been demonstrated to provide protection from infections and improve health-related quality of life. Data supporting current options in IgG replacement are presented, and considerations in choosing between the two routes of therapy are discussed.

Primary immune deficiencies - principles of care

Primary immune deficiencies (PIDs) are a growing group of over 230 different disorders caused by ineffective, absent or an increasing number of gain of function mutations in immune components, mainly cells and proteins. Once recognized, these rare disorders are treatable and in some cases curable. Otherwise untreated PIDs are often chronic, serious, or even fatal. The diagnosis of PIDs can be difficult due to lack of awareness or facilities for diagnosis, and management of PIDs is complex. This document was prepared by a worldwide multi-disciplinary team of specialists; it aims to set out comprehensive principles of care for PIDs. These include the role of specialized centers, the importance of registries, the need for multinational research, the role of patient organizations, management and treatment options, the requirement for sustained access to all treatments including immunoglobulin therapies and hematopoietic stem cell transplantation, important considerations for developing countries and suggestions for implementation. A range of healthcare policies and services have to be put into place by government agencies and healthcare providers, to ensure that PID patients worldwide have access to appropriate and sustainable medical and support services.

Immune globulin (human) 10 % liquid: a review of its use in primary immunodeficiency disorders

Human immune globulin (IG) 10 % liquid (Gammagard Liquid®) is a ready-to-use, highly purified, and concentrated immunoglobulin (Ig)G solution approved in the US for both intravenous and subcutaneous antibody replacement therapy in patients aged ≥ 2 years with primary humoral immunodeficiency. Intravenous IG 10 % liquid every 3-4 weeks for ≥ 12 months, at median serum IgG trough levels of 9.6-11.2 g/L, completely prevented acute serious bacterial infections (SBIs) in a phase III clinical trial. Weekly subcutaneous IG 10 % liquid at a dose equal to 137 % of the equivalent weekly intravenous dose, which was earlier determined to produce the same IgG exposure, produced higher serum trough IgG levels and lower peak IgG levels than intravenous administration, and also effectively reduced SBIs; the infection rate was 0.067 SBIs/subject/year, which met the US FDA efficacy criterion of < 1 SBI/subject/year. The rates for non-serious infections of any kind were low for both intravenous and subcutaneous therapy. Both intravenous and subcutaneous IG 10 % liquid were safe and generally well tolerated. Systemic adverse reactions were more frequent with intravenous therapy and local infusion-site reactions were more frequent with subcutaneous therapy, but the latter reduced over time. Most adverse reactions were of mild or moderate intensity. Thus, IG 10 % liquid is an effective and generally well-tolerated preparation for both intravenous and subcutaneous IgG replacement therapy in patients with primary immunodeficiency disorders involving antibody deficiency. It offers the benefits of a ready-to-use, liquid preparation and the convenience of home-based therapy in appropriate patients.

Optimizing immunoglobulin treatment for patients with primary immunodeficiency disease to prevent pneumonia and infection incidence: review of the current data

BACKGROUND

An increasing body of evidence suggests that the optimal dose for IgG replacement therapy is the dose that keeps the patient as free from infection as possible by either intravenous or subcutaneous delivery.

OBJECTIVE

To review the current evidence on optimizing IgG therapy in patients with primary immunodeficiency disease (PIDD).

METHODS

Surveys conducted among physicians who treat patients with PIDD indicate that most practitioners follow existing data and guidelines on the use and dosage of immunoglobulin therapy. On the basis of the current guidelines, most use intravenous immunoglobulin (IVIG) therapy at a starting dose of 400 mg/kg every 4 weeks to treat a number of primary PIDDs with humoral immune deficiencies. However, for the optimal treatment of PIDDs, therapy needs to be tailored.

RESULTS

Among the issues is the assessment of IgG trough levels or steady-state levels with subcutaneous immunoglobulin (SCIG) therapy needed to reduce or prevent infection in patients with PIDD. Increasing evidence suggests that optimization of treatment can be based on identifying the dosage of IVIG or SCIG for each patient needed to reduce infection.

CONCLUSION

More studies are needed to better clarify the optimal dose, IgG trough level, or IgG steady-state level necessary to reduce infection and optimize treatment for patients with PIDD treated with IVIG or SCIG.

Controversies in IgG replacement therapy in patients with antibody deficiency diseases

This Current perspectives article will review and highlight the importance of accurate diagnosis of patients who have failed to produce specific antibodies to naturally encountered foreign proteins or polysaccharides or after vaccination and the appropriate institution of immunoglobulin replacement therapy. The field of primary immunodeficiency disease (PIDD) has expanded remarkably since the early descriptions 6 decades ago. With greater recognition and advanced cellular and molecular diagnostic technology, new entities and single-gene defects in patients with PIDD are rapidly being defined. This, combined with treatment advances and newborn screening for severe combined immunodeficiency, has resulted in improved outcomes and survival and even permanent cures. Awareness of PIDD has also increased, but the guidelines for recognition remain to be validated. The zeal for registering and enrolling patients has potentially created a large body of "patients" treated with immunoglobulin replacement unnecessarily. The complexity, diversity, and availability of laboratory testing have brought awareness of PIDD to the forefront, but because of an absence of standardization of certain assays, concerns about the correct diagnosis and appropriate treatment have increased. We hope to refocus the discussion on identifying clear laboratory and clinical guidelines for the establishment of an accurate diagnosis of antibody deficiency, its rationale, and, where indicated, institution of safe treatment.

Broadening the translational immunology landscape

It is just over 5 years sinceClinical and Experimental Immunology came under the direction of a new team of Editors and made a concerted effort to refresh its approach to promoting clinical and applied immunology through its pages. There were two major objectives: to foster papers in a field which, at the time, we loosely termed ‘translational immunology’; and to create a forum for the presentation and discussion of immunology that is relevant to clinicians operating in this space. So, how are we doing with these endeavours? This brief paper aims to summarize some of the key learning points and successes and highlight areas in which translational gaps remain.