Subcutaneous immunoglobulin replacement in primary immunodeficiencies

Efficacy and safety of subcutaneous human HBV-immunoglobulin (Zutectra) in liver transplantation: an open, prospective, single-arm phase III study

Hepatitis B re-infection prophylaxis is crucial for graft and recipient survival for transplanted patients and is administered routinely after liver transplantation for hepatitis B. Aim of the current study was the investigation of efficacy, safety and feasibility of home-treatment of a novel human hepatitis B immunoglobulin BT088 (Zutectra) after weekly subcutaneous application in liver-transplanted patients. A total of 23 patients (5 female, 18 male, median age 51 years) were enrolled and switched from monthly IV to weekly SC hepatitis B immunoglobulin administration. During a period of 18 weeks (optional 24 weeks) anti-HBs levels, signs of re-infection, adverse events and feasibility of self-administration were studied. After 8 weeks of training patients showing good compliance and stable antibody titres were allowed to start self-administration at home. All patients maintained a safety level of >100 U/l anti-HBs. No failure was noted, no re-infection occurred. A total of 10 treatment-emergent events were assessed as related to study drug application (injection-site haematoma, headache, abdominal pain, fatigue and haematuria). High numbers of self-administration (287 vs. 122 by staff) demonstrated general feasibility of SC administration. Weekly subcutaneous administration of BT088 (Zutectra - registered trade mark in the EU) is effective, safe and presents an easy-to-apply treatment option for combined hepatitis B virus re-infection prophylaxis in liver transplant patients (Eudra CT Number: 2005-003737-40).

Pharmacokinetics of subcutaneous immunoglobulin and their use in dosing of replacement therapy in patients with primary immunodeficiencies

Bioavailability and pharmacokinetics of subcutaneous IgG (SCIG) and intravenous IgG (IVIG) differ. It is not clear if and/or how the dose should be adjusted when switching from IVIG to SCIG. Area under the curve (AUC) of serum IgG versus time and trough level ratios (TLRs) on SCIG/IVIG were evaluated as guides for adjusting the dose. The mean dose adjustments required for non-inferior AUCs with 2 different SCIG preparations were 137% (± 12%) and 153% (± 16%). However, there were wide variations between adjustments required by different subjects, and in the resulting TLRs. In contrast, combined data from multiple studies allow estimation of the ratio of IgG levels with different dose adjustments, and of the steady state serum levels with different SCIG doses. When switching a patient from IVIG to SCIG, individualizing the dosage based on measured serum IgG levels and the clinical response is preferable to using mean pharmacokinetic parameters.

Immunoglobulin dosage and switch from intravenous to subcutaneous immunoglobulin replacement therapy in patients with primary hypogammaglobulinemia: decreasing dosage does not alter serum IgG levels

OBJECTIVE

The impact of reducing immunoglobulin dosage while switching from intravenous to subcutaneous replacement therapy was evaluated.

METHODS

Sixty-five patients with primary hypogammaglobulinemia on stable intravenous replacement therapy were included in a monocentric longitudinal trial. IgG trough levels were measured at baseline and during 1 year following the switch to the subcutaneous route.

RESULTS

Mean IgG trough level after 12 months of subcutaneous therapy was increased by 5.4 percent (8.37-8.82 g/l, p=0.3), while immunoglobulin dosage had been reduced by 28.3% (151-108 mg/kg/week, p<0.0001). For the patients with the lowest serum IgG level upon intravenous infusions, serum IgG level rose by 37 percent (5.33-7.33 g/l, p=0.003), while mean immunoglobulin dosage was reduced by 36 percent (170-109 mg/kg/week, p=0.04).

CONCLUSION

The present study shows that sustained serum IgG levels can be achieved after switching towards subcutaneous replacement despite using reduced immunoglobulin doses.

Improved quality of life, immunoglobulin G levels, and infection rates in patients with primary immunodeficiency diseases during self-treatment with subcutaneous immunoglobulin G

OBJECTIVES

Primary immunodeficiency diseases (PIDDs) include a large class of genetically heterogeneous disorders which predispose patients to significant risk of serious and chronic/recurrent infections, as well as reduced quality of life (QoL). Intravenous immunoglobulin (IVIG) therapy improves the well being of PIDD patients; however, the need for venous access and potentially severe side effects frequently require administration in medical facilities. We evaluated the long-term (12-month) experience with home-based self infusions of subcutaneous immune globulin (SCIG) in patients with PIDD on health-related QoL, rates of serious bacterial infections, and all other infections.

METHODS

Adults (n = 42) and children (n = 9) with PIDD, previously treated with clinic-based IVIG, were trained to self administer SCIG at home. QoL (SF-36(R) and CHQ-PF50 questionnaires), serious bacterial infections, serum immunoglobulin G (IgG) levels, overall infections, and incidence of adverse events were recorded at predetermined intervals.

RESULTS

All patients had improved perceptions of general health (adults P = 0.047, children P = 0.037). Adults also had marked improvement in the bodily pain and vitality assessments, and parents had improved perceptions of personal and family activities. Serum IgG levels were maintained at mean levels 25% higher than previous troughs on IVIG. There were 162 infections overall for an annual rate of 3.42/patient, but only 1 serious bacterial infection was observed (0.03/patient/yr). An average of 4.5 days/yr was missed from work or school per patient.

CONCLUSIONS

Home SCIG therapy was safe and led to improved perceptions of general health, higher serum IgG levels, and very low rates of infections and days missed from work/school.

Home-based subcutaneous immunoglobulin G replacement therapy under real-life conditions in children and adults with antibody deficiency

Background

Subcutaneous immunoglobulin (SCIG) therapy is an alternative to intravenous immunoglobulin (IVIG) therapy.

Methods

We evaluated the efficacy and safety of the SCIG Vivaglobin^® (formerly known as Beriglobin^® SC) under real-life conditions in a post-marketing observational study in 82 patients with primary or secondary antibody deficiencies. Health-related quality of life (HRQoL) was evaluated in a subset of 30 patients previously treated with IVIG (including 11 children < 14 years) using the Short Form 36 (SF-36) for patients ≥ 14 years of age (adults) and the Child Health Questionnaire - Parental Form 50 (CHQ-PF50) for children < 14 years of age. Treatment preferences were assessed in adults.

Results

The mean serum immunoglobulin G (IgG) trough level during SCIG treatment (7.5 g/L) was higher than during previous IVIG treatment (6.6 g/L; p < 0.01). The investigators assessed the efficacy of SCIG therapy as "excellent" in 89% of patients. No systemic adverse drug reactions were observed. Improvements by ≥ 5 points were observed in 5 of 8 SF36 subscales and in 6 of 12 CHQ-PF50 subscales. Statistically significant improvements (p ≤ 0.05) were observed for the SF-36 subscales of bodily pain, general health perceptions, and vitality (adults), and for the CHQ-PF50 subscales of general health perceptions, parental impact - time, parental impact - emotional, and family activities (children). Patients preferred SCIG over IVIG therapy (92%) and home therapy over therapy at the clinic/physician (83%).

Conclusion

This study confirms that therapy with Vivaglobin^® at home is effective, safe, well tolerated, and improves quality of life in patients with antibody deficiency.

Impact of trough IgG on pneumonia incidence in primary immunodeficiency: A meta-analysis of clinical studies

Primary immunodeficiency disease (PIDD) associated with hypogammaglobulinemia is typically treated with immunoglobulin replacement therapy. When administered as intravenous immunoglobulin (IVIG), an IgG trough occurs prior to the next replacement dose. While frequently measured, IgG trough levels required to minimize infection risk are not established. To address this question, all available studies evaluating trough IgG and pneumonia incidence in PIDD patients with hypogammaglobulinemia receiving IVIG were quantitatively combined by meta-analysis. Seventeen studies with 676 total patients and 2,127 patient-years of follow-up were included. Pneumonia incidence declined by 27% with each 100mg/dL increment in trough IgG (incidence rate ratio, 0.726; 95% confidence interval, 0.658-0.801). Pneumonia incidence with maintenance of 500 mg/dL IgG trough levels (0.113 cases per patient-year) was 5-fold that with 1000 mg/dL (0.023 cases per patient-year). This meta-analysis provides evidence that pneumonia risk can be progressively reduced by higher trough IgG levels up to at least 1000 mg/dL.

Common variable immunodeficiency: etiological and treatment issues

One of the great advances in clinical medicine was the recognition of the pleomorphism of the immune response and the multiple afferent and efferent limbs of antigen processing and responsiveness. A significant contribution to this understanding was derived from studies of human immunodeficiency states, including both inherited and acquired syndromes. Amongst these syndromes, one of the most common, and least understood, is common variable immune deficiency (CVID). CVID is a syndrome that leads to a reduction in serum immunoglobulins and complications including recurrent infections. Management includes immunoglobulin replacement therapy; however, patients with CVID are at risk for complications of exogenous immunoglobulin administration as well as CVID-associated diseases such as autoimmune processes and malignancies. To assess the current state of knowledge in the field, we performed a literature review of a total of 753 publications covering the period of 1968 until 2008. From this list, 189 publications were selected for discussion. In this review, we demonstrate that while the molecular basis of CVID in many cases remains incompletely understood, significant strides have been made and it is now clear that there is involvement of several pathways of immune activation, with contributions from both T and B cells. Furthermore, despite the current gaps in our knowledge of the molecular pathogenesis of the syndrome, there have been dramatic advances in management that have led to improved survival and significantly reduced morbidity in affected patients.

Primary B cell immunodeficiencies: comparisons and contrasts

Sophisticated genetic tools have made possible the identification of the genes responsible for most well-described immunodeficiencies in the past 15 years. Mutations in Btk, components of the pre-B cell and B cell receptor (lambda5, Igalpha, Igbeta), or the scaffold protein BLNK account for approximately 90% of patients with defects in early B cell development. Hyper-IgM syndromes result from mutations in CD40 ligand, CD40, AID, or UNG in 70-80% of affected patients. Rare defects in ICOS or CD19 can result in a clinical picture that is consistent with common variable immunodeficiency, and as many as 10% of patients with this disorder have heterozygous amino acid substitutions in TACI. For all these disorders, there is considerable clinical heterogeneity in patients with the same mutation. Identifying the genetic and environmental factors that influence the clinical phenotype may enhance patient care and our understanding of normal B cell development.

Resolution of warts in association with subcutaneous immunoglobulin in immune deficiency

Common variable immunodeficiency is the most common severe primary immunodeficiency. Most common variable immunodeficiency patients have progressive hypogammaglobulinemia involving all immunoglobulin classes, poor or absent antibody responses, and recurrent bacterial infections, usually of the sino-respiratory tract. Some may present with complicated cutaneous infections like furunculosis (J Allergy Clin Immunol; 109: 581) or recurrent cutaneous warts. Here, we report the case of an 18-year-old male diagnosed with common variable immunodeficiency who had extensive cutaneous warts that resolved within 2 months of starting weekly infusions of subcutaneous immunoglobulin.

Subcutaneous administration of IgG

The availability of IgG preparations that could be administered safely by the intravenous route was finally achieved in the early to mid-1980s. Intravenous immunoglobulin (IVIG) revolutionized the treatment of primary immune deficiency diseases (PIDD) and led to the discovery of the therapeutic value of high-dose IgG in autoimmune and inflammatory diseases not associated with PIDD. Improved therapy has improved outcomes and expectations, and most PIDD patients can lead fully active and productive lives. Administration of IgG by the subcutaneous route is effective and safe and overcomes obstacles to the use of IVIG in some patients. Many patients find administration of subcutaneous IgG at home more convenient than receiving IVIG at the Doctor's office or hospital. The coming years will see increased use of subcutaneous immunoglobulin in PIDD, which will be facilitated by advances leading to higher-concentration IgG products and easier delivery.

Pharmacokinetics of immunoglobulin administered via intravenous or subcutaneous routes

This article reviews pharmacokinetic studies of IgG administration by intravenous and subcutaneous routes. Intravenous immunoglobulin pharmacokinetics have been studied during replacement therapy for primary and secondary immunodeficiencies and other special circumstances (eg, infection prophylaxis in neonates). Subcutaneous immunoglobulin pharmacokinetics have been studied only during replacement therapy for primary immunodeficiency. Published studies vary greatly with respect to the nature of the patients studied, dose regimens, sampling schedules, and pharmacokinetic models, making comparisons difficult. With either route of administration, there is large variation in individual IgG elimination rates. Periodic measurement of serum IgG concentration is critical to monitor the adequacy of replacement during therapy.

Primary antibody deficiency syndromes

The primary antibody deficiency syndromes are a group of rare disorders characterized by an inability to produce clinically effective immunoglobulin responses. Some of these disorders result from genetic mutations in genes involved in B cell development, whereas others appear to be complex polygenic disorders. They most commonly present with recurrent infections due to encapsulated bacteria, although in the most common antibody deficiency, Common Variable Immunodeficiency, systemic and organ-specific autoimmunity can be a presenting feature. Diagnostic delay in this group of disorders remains a problem, and the laboratory has a vital role in the detection of abnormalities in immunoglobulin concentration and function. It is critical to distinguish this group of disorders from secondary causes of hypogammaglobulinaemia, in particular lymphoid malignancy, and appropriate laboratory investigations are of critical importance. Treatment of primary antibody deficiencies involves immunoglobulin replacement therapy, either via the intravenous or subcutaneous route. Patients remain at risk of a wide variety of complications, not all linked to diagnostic delay and inadequate therapy. In common variable immunodeficiency (CVID) in particular, patients remain at significantly increased risk of lymphoid malignancy, and regular clinical and laboratory monitoring is required. This review aims to give an overview of these conditions for the general reader, covering pathogenesis, clinical presentation, laboratory investigation, therapy and clinical management.

Preparation and use of therapeutic antibodies primarily of human origin

Therapeutic antibodies include polyclonal immunoglobulins isolated from regular or high-titered human plasma, sera from immunized animals, and monoclonal antibodies. This array of therapeutic antibodies is used for the prevention and treatment of many infectious diseases, antibody immunodeficiencies, autoimmune and inflammatory diseases, neurological disorders, and cancers. Polyclonal human immunoglobulins are available for intramuscular injection (IGIM), intravenous infusion (IGIV) and subcutaneous infusion (SCIG). We review these products and detail the therapeutic use of polyclonal human antibodies in the treatment of antibody immunodeficiencies, including their occasional local side effects (tenderness, sterile abscesses), minor systemic side effects (chills, muscle aches, malaise, headaches) and major side effects (aseptic meningitis, nephropathy, thrombosis).

Principles of and advances in immunoglobulin replacement therapy for primary immunodeficiency

During the last 2 decades, the continued development and the large-scale production of polyclonal immune serum globulin (ISG) preparations with improved safety and tolerability profiles have allowed treatment to focus on quality of life and long-term freedom from the complications of primary immune deficiency disease, rather than just on freedom from severe acute infections and survival. Available ISG preparations allow routine therapy by a variety of routes and regimens that can be tailored to suit individual patients. Continued vigilance is required, however, because problems with emerging diseases, and the costs and availability of ISG are likely to present continuing challenges.

Rapid subcutaneous immunoglobulin administration every second week results in high and stable serum immunoglobulin G levels in patients with primary antibody deficiencies

Subcutaneous immunoglobulin G (SCIG) infusions as life-long replacement therapy in patients with primary antibody deficiences (PAD) is being applied increasingly. However, only a few published pharmacokinetic studies are available for this route of administration. Therefore, the pharmacokinetics of a 16% immunoglobulin G (IgG) preparation intended for subcutaneous use were investigated in patients with common variable immunodeficiency and X-linked agammaglobulinaemia. SCIG infusions (200 mg/kg body weight) were administered to 12 adult patients every 14 days for 24 weeks (total of 144 infusions). Pharmacokinetic parameters were determined based on serum IgG trough levels and antibody levels against tetanus. The median half-life of the total serum IgG and for the tetanus antibodies was 40.6 and 23.3 days respectively. Median in vivo recovery of serum IgG and tetanus immunoglobulins were 36% and 46% respectively. Median, preinfusion serum IgG trough levels per patient were high without major variations between infusions and ranged from 7.24 to 7.86 g/l. Safety, in terms of adverse events including systemic adverse reactions and local tissue reactions at infusions sites, was monitored throughout the study. Six mild, local tissue reactions were observed during the study in one patient. No systemic adverse reactions related to the study drug were observed and no serious other adverse event occurred during the study. It is concluded that the bi-weekly SCIG therapy was well tolerated in the study and that it results in high and stable serum IgG levels, offering an alternative therapy regimen to patients suffering from PAD.

Quality of life and health-care resource utilization among children with primary immunodeficiency receiving home treatment with subcutaneous human immunoglobulin

INTRODUCTION

Among patients with antibody deficiency, patient-reported outcomes are important for choosing between equally effective treatment regimens.

PATIENTS AND METHODS

Twelve children (1.7-17.1 years) with primary immunodeficiency were switched from hospital-based intravenous IgG treatment to home treatment with subcutaneous IgG. Quality of life (Child Health Questionnaire) and health-care resource utilization were assessed at baseline and after 3 and 6 months.

RESULTS

From the parents' perspective, significant improvements were seen after 6 months for mental health (median difference; 95% confidence interval, 15.0; 0.0, 22.5); change in health (1.0; 0.0, 2.0); and family activities (12.5; 2.1, 25.0). From the children's' perspective, significant improvements were seen for role/social limitations-emotional at 3 (22.2; 11.1, 33.3) and 6 months (22.2; 11.1, 66.7) and global health at 6 months (35.0; 15.0, 55.0). There were no significant improvements in other concepts. Subcutaneous IgG treatment significantly reduced absence days, days spent on hospital/physician visits, and health-care-related expenses.

CONCLUSION

Switching to home-based subcutaneous IgG treatment led to significant improvements in quality of life and substantial cost savings.

Subcutaneous immunoglobulin therapy in an 11-year-old patient with common variable immunodeficiency and von Willebrand disease

BACKGROUND

Subcutaneous immunoglobulin (SCIG) is an option for replacement therapy in patients with humoral immune deficiencies.

OBJECTIVE

To describe a patient with common variable immunodeficiency (CVID) and von Willebrand disease who tolerated immunoglobulin replacement via the subcutaneous route.

METHODS

An 11-year-old boy receiving monthly intravenous immunoglobulin (IVIG) since 5 years of age presented to an academic medical center after moving to the area. The patient also had a history of von Willebrand disease. He had started receiving IVIG because of recurrent infections and an absent IgG subclass 3. Further immunologic assessment revealed a normal B-cell count, decreased IgM level, and an abnormal response to bacteriophage phiX174. Given these findings and the lack of another cause, the patient was diagnosed as having CVID. Because of difficult intravenous access, a port was placed for IVIG administration in 1999. The initial port was removed because of infectious complications, and a second port was found to be distally displaced in the right atrium, requiring removal.

RESULTS

Continued difficulties with intravenous access and the potential complications with maintaining a long-term indwelling catheter prompted consideration of alternative methods for immunoglobulin administration. After removal of the port, the patient was prescribed weekly SCIG infusions. He tolerated the infusions well without bleeding complications related to the von Willebrand disease and was able to transition to home infusions.

CONCLUSIONS

SCIG was well tolerated by a pediatric patient with CVID and von Willebrand disease without any significant bleeding complications.

Safety and efficacy of subcutaneous human immunoglobulin in children with primary immunodeficiency

The primary objective of this prospective, open-label study was to evaluate the safety and tolerability of home treatment with a 16%, ready-to-use, human normal immunoglobulin solution for subcutaneous administration (SCIg 16%, Subcuvia, Baxter Medical AB, Kista, Sweden) in children with primary immunodeficiency (PI) previously receiving intravenous immunoglobulins (IVIg) treatment. Secondary objectives were to evaluate the efficacy of SCIg 16% through documented bacterial infections, IgG trough levels, quality of life (Child Health Questionnaire [CHQ]), healthcare resource utilization and patient preference. Twelve patients with PI were included in the study. There were no significant changes from baseline in vital signs or laboratory parameters. Most adverse events (311 of 328) were mild injection site reactions that, in most cases, resolved after 1-2 months. SCIg 16% maintained consistently high IgG trough levels, and the rate of bacterial infections was not different from that seen with previous IVIg treatment. SCIg treatment was also associated with significantly fewer lost work and school days and lower direct healthcare-related expenses and time consumed due to hospital or physician visits.

CONCLUSION

Home-based SCIg treatment was well tolerated, at least as effective as IVIg for preventing infections, and preferred by children with PI previously receiving IVIg treatment.

Immunoglobulin treatment for primary antibody deficiencies: advantages of the subcutaneous route

Adults and children with primary antibody deficiencies are prone to bacterial infections affecting the respiratory tract and gastrointestinal canal. To prevent or alleviate infections, replacement therapy with IgG is needed, usually on a lifelong basis. The IgG can be administered intramuscularly, intravenously, or subcutaneously. Subcutaneous IgG (SCIG) therapy, using small portable pumps for once-per-week self infusions, has shown many advantages compared with the two other routes of administration. This review highlights findings from international studies and demonstrates that: (i) SCIG therapy is safe, with very few adverse effects; (ii) the therapy can be used for patients with previous adverse effects to intravenous administration of IgG; (iii) the therapy leads to high serum IgG levels and good protection against infections; (iv) the therapy facilitates home therapy, as the infusion technique is easy for children, adults and elderly people to learn and there is no need for venous access; (v) SCIG home therapy leads to significantly improved life situations for the patients; (vi) the SCIG home therapy regimen in particular reduces the costs of treatment.

Subcutaneous immunoglobulin for patients with antibody deficiency

This article provides an overview on the management of primary immunodeficiency, and discusses the pharmacokinetics of subcutaneous and intravenous immunoglobulin and the relationship between blood levels and therapeutic effects in both treatments. The article will further highlight both treatments' efficacy in preventing infections and the risk of systemic side effects with each treatment.

Replacement IgG therapy and self-therapy at home improve the health-related quality of life in patients with primary antibody deficiencies

PURPOSE OF REVIEW

This article describes the health-related quality of life and health of patients suffering from primary antibody deficiencies before and after the initiation of lifelong IgG replacement therapy, and before and after the introduction of home-therapy regime programmes. The importance of including patient-reported or parent-reported outcomes in evaluations of treatment and care of this group of patients is also discussed.

RECENT FINDINGS

Recently diagnosed adults suffering from primary antibody deficiencies and not yet on IgG therapy report poor health and poor health-related quality of life as compared with healthy individuals. Weekly subcutaneous IgG infusions (100 mg/kg) significantly improve health and normalize health-related quality of life. IgG self-infusions at home further improve the self-reported health and health-related quality of life of both adults and children. Being able to self-infuse at home instead of visiting the hospital two to four times per month has been shown to increase the treatment satisfaction of both adult patients and their families, and to result in increased flexibility, independence and sense of self-control.

SUMMARY

Adequate IgG replacement therapy means a dramatically improved life situation. Home-therapy programmes should be encouraged, as self-infusions at home further improve health-related quality of life and self-perceived health.

Safety and efficacy of self-administered subcutaneous immunoglobulin in patients with primary immunodeficiency diseases

Intravenous immunoglobulin (IVIg) infusions at 3-4 week intervals are currently standard therapy in the United States for patients with primary immune deficiency diseases (PIDD). To evaluate alternative modes of immunoglobulin administration we have designed an open-label study to investigate the efficacy and safety of a subcutaneously administered immunoglobulin preparation (16% IgG) in patients with PIDD. After their final IVIg infusion, 65 patients entered a 3-month, wash-in/wash-out phase, designed to bring patients to steady-state with subcutaneously administered immunoglobulin. This was followed by 12 months of weekly SCIg infusions, at a dose determined in a pharmacokinetic substudy to provide noninferior intravascular exposure. This resulted in a mean weekly dose of 158 mg/kg, calculated to equal 137% of the previous intravenous dose. Two patients (4%) each reported 1 serious bacterial infection (pneumonia), an annual rate of 0.04 per patient-year. There were 4.43 infections of any type per patient-year. Mean trough serum IgG levels increased from 786 to 1040 mg/dL during the study, a mean increase of 39%. The most frequent treatment-related adverse event was infusion-site reaction, reported by 91% of patients; this was predominantly mild or moderate, and the incidence decreased over time. No treatment-related serious adverse events were reported. We conclude that subcutaneous administration of 16% SCIg is a safe and effective alternative to IVIg for replacement therapy of PIDD.

Health-related quality of life and treatment satisfaction in North American patients with primary immunedeficiency diseases receiving subcutaneous IgG self-infusions at home

The lifelong IgG replacement therapy for patients with primary immunedeficiencies (PIDD) may be provided by intravenous (IVIG) or by subcutaneous IgG (SCIG) infusions. We investigated the impact of weekly SCIG self-infusions at home on the health-related quality of life, treatment satisfaction, and preferences in patients treated with IVIG at the hospital/doctor's office (Group A) or at home (Group B) before the study started. Forty-four adult North American PIDD patients were included in the study, 28 patients in Group A and 16 in Group B. Patients in Group A reported significantly less limitations with their work/daily activities, a significantly improved vitality, and better general health. Treatment satisfaction was significantly improved in Group A. The preference for the subcutaneous route and for home therapy was respectively 81% and 90% in Group A. In Group B, 69% preferred the subcutaneous route and 92% home therapy.

Rapid Subcutaneous IgG Replacement Therapy is Effective and Safe in Children and Adults with Primary Immunodeficiencies—A Prospective, Multi-National Study

Sixty patients (16 children, 44 adults) participated in the study aiming at evaluating: (i) IgG levels when switching patients from intravenous IgG (IVIG) infusions in hospital to subcutaneous (SCIG) self-infusions at home using the same cumulative monthly dose, (ii) protections against infections, and (iii) safety of a new, ready-to-use 16% IgG preparation. All children and 33 adults had received IVIG therapy for >6 months at enrolment. Ten adults who had been on SCIG therapy for many years served as controls. Mean serum IgG trough levels increased in the pre-IVIG children from 7.8 to 9.2 g/L (non-inferiority: p < 0.001) and in the adults from 8.6 to 8.9 g/L (non-inferiority: p < 0.001). Totally 114 respiratory tract infections occurred, 90% of them mild. One serious bacterial infection (pneumonia) was reported for one adult. The annualized rate of serious infections was 0.04 episodes/patient. In total 2297 infusions were given and 28 (1%) systemic adverse reactions occurred, none of them severe. Local tissue reactions declined over time, this being particularly distinct after 8 to 10 weeks. In conclusion, the SCIG administration route was safe. High IgG levels were easily maintained resulting in a very good protection against infections.

Measuring treatment satisfaction in patients with primary immunodeficiency diseases receiving lifelong immunoglobulin replacement therapy

BACKGROUND

Treatment satisfaction of patients with primary immunodeficiency diseases receiving hospital-based intravenous (IVIG) or home-based subcutaneous (SCIG) immunoglobulin infusions requires investigation.

OBJECTIVE

Evaluation of the properties and suitability of the Life Quality Index (LQI), as an instrument to assess treatment satisfaction.

METHODS

Patients received weekly SCIG and completed the LQI, two global treatment satisfaction questions and the CHQ-PF50 (children) or the SF-36 (adults) at baseline and 10 months. The LQI was psychometrically evaluated.

RESULTS

The LQI comprised four scales: treatment interference (I), therapy related problems (II), therapy setting (III), treatment costs (IV). Convergent/discriminant validity for scales I, II, III was acceptable, for scale IV moderate. CHQ-PF50 scales behavior, bodily pain, global behavior, global health, mental health, parental impact-emotion significantly correlated with LQI scale II, the family activity scale with LQI scales I, III. SF-36 scale bodily pain significantly correlated with scale III. Internal consistency was good for scales I, II, III, but poor for scale IV. Score values significantly increased for scales I, III, IV in patients switching from IVIG to SCIG.

CONCLUSIONS

Three valid LQI scales were determined. Cost-related questions should be removed due to low reliability. Patients-perceived therapy effectiveness and patient-physician/nurse interaction should be included in the instrument.

Subcutaneous immunoglobulin-g replacement therapy with preparations currently available in the United States for intravenous or intramuscular use: reasons and regimens

For patients who require replacement therapy for primary immunodeficiency, subcutaneous infusions of immunoglobulin G (IgG) may be preferable to intravenous infusions for several reasons. However, at present, there is no preparation marketed for use by this route in North America. In this article, we describe the reasons patients have selected this route of therapy and the range of treatment regimens used. Approximately 20% of our patients have chosen the subcutaneous route, mainly because of adverse effects from intravenous (IV) infusions or difficulties with venous access. Unit dose regimens using whole bottles of currently available 16% intramuscular preparations or sucrose-containing lyophilized preparations intended for IV use but reconstituted to 15% IgG for subcutaneous administration were individually tailored to each patient. In most cases, self-infusions or home infusions were administered once or twice a week, most commonly requiring two subcutaneous sites and 2 to 3 hours per infusion. On average, patients took 0.18 mL of IgG per kilogram of body weight per site per hour. There were no systemic adverse effects. In patients for whom comparative data were available, trough serum IgG levels were higher with subcutaneous therapy than with IV therapy.

Common variable immunodeficiency: test indications and interpretations

Common variable immunodeficiency (CVID) is a primary immunodeficiency disorder that can present with multiple phenotypes, all of which are characterized by hypogammaglobulinemia, in a person at any age. A specific genetic defect that accounts for all CVID phenotypes has not been identified, and it is likely that several distinct genetic disorders with similar clinical presentations are responsible for the observed variation. In this review, we summarize the known genetic mutations that give rise to hypogammaglobulinemia and how these gene products affect normal or abnormal B-cell development and function, with particular emphasis on CVID. Additionally, we describe specific phenotypic and genetic laboratory tests that can be used to diagnose CVID and provide guidelines for test interpretation and subsequent therapeutic intervention.