Dosing Strategy of Immunoglobulin (IgG) Replacement Therapies in Obese and Overweight Patients with Primary Immunodeficiency Diseases (PIDDs): A Meta-Analysis of Clinical Trials

The current dosing strategy of immune globulin products for the treatment of primary immunodeficiency diseases (PIDDs) in the USA is based on total body weight (BW). The aim of our study was to assess the relationship between dose and trough level, and to determine whether an alternative dosing strategy should be considered for patients who are overweight or obese. We analyzed data in a total of 533 patients from 11 studies. We modeled the relationship between trough level and dose per week using a linear mixed model. We used an over-dispersed Poisson model to model the relationship between infection and trough level. In these analyses, we then combined the study-specific treatment effects using a random-effect or fixed-effect model. The mean administered dose per week was 9.77, 14.00, or 18.17 g in patients who were normal weight, overweight, or obese, respectively. Compared with a patient of normal weight, a 1 g increase in dose per week in a patient who was overweight was associated with a smaller increase in the trough level, 0.08 g/L less (95%CI -0.14 to -0.03 g/L), and a 1 g increase in dose per week in a patient who was obese was associated with a much smaller increase in trough level, 0.01 g/L less (95% CI -0.07 to 0.06 g/L). Last, for a 1 unit (g/L) increase in trough level, the expected number of infections remained the same, with a multiplicative factor of 1.01 (95%CI 0.98-1.04). Overall, we found no compelling evidence to justify a reconsideration of the current dosing strategy based on total BW for patients with PIDDs who are overweight or obese.

Low-dose intravenous immunoglobulin (IVIg) in different immune-mediated conditions

IVIg has been used for a long time as a replacement therapy for primary and secondary immunodeficiencies. Beside this supplementary role, when used at higher doses (i.e., 2 g/kg/monthly) it exerts an immunomodulatory role able to control multiple autoimmune and systemic inflammatory diseases. Several mechanisms of action have been described and hypothesized, nonetheless a synergistic action on the different component of the immune response seems to be crucial. The other side of the coin are the costs which showed an increase during the years due to the production of highly purified preparations which limit side reactions. This renders the product not easily accessible especially for low-income countries. Moreover, it is based on plasma donations that experienced a significant shrinkage after the COVID-19 pandemic and the consequences are still impactful. Due to the above-mentioned problems different authors tried to find out if a lower dosage of IVIg (< 2 g/kg/monthly) might exert an immunoregulatory role. In this review we aimed to summarize the current literature about a possible beneficial effect of a lower dosage of IVIg in multiple conditions that would help to treat a vast majority of patients. Even though in some cases (e.g., Kawasaki disease and immune thrombocytopenia) results are promising, for other conditions more research is needed.

Relationship between Body Composition and Serum Immunoglobulin Concentrations after Administration of Intravenous Immune Globulin-Preclinical and Clinical Evidence

The purpose of this study was to investigate the effect of obesity on immunoglobulin G (IgG) pharmacokinetics in a rat model of obesity, and to collect clinical evidence for an association between the body composition and intravenous immune globulin (IVIG) pharmacokinetic parameters in humans. In a preclinical study, pharmacokinetics of human IgG was evaluated after intravenous (IV) and subcutaneous (SC) delivery to obese and lean rats (n = 6 in each group). Serial serum samples were analyzed using an ELISA. The animal body composition was assessed using computer tomography. Patients with primary immunodeficiency currently managed with IVIG, and at a steady state, were enrolled in the clinical study (n = 8). Serum immune globulin (Ig) concentrations were measured at baseline and immediately after the administration of two consecutive treatments, with an additional measurement at two weeks after the first administration. In addition to the patient demographic and clinical characteristics, body composition was measured using bioelectrical impedance analysis. The pharmacokinetics of human IgG was significantly different between the obese and lean rats after both the IV and SC administration of 0.5 g/kg. Furthermore, a significant difference in endogenous rat IgG was observed between the two strains. In the human study, total serum IgG and subtype (IgG1, IgG2, IgG3, IgG4) half-life negatively correlated with the body mass index and fat mass. The mean change in the total serum IgG concentration was significantly correlated to body mass index and fat mass. The results of the studies corroborated one another. In the animal study, most pharmacokinetic parameters of human IgG following IV and SC administration were significantly affected by obesity and changes in the body composition. In the clinical study, the mean serum IgG change after the IVIG administration strongly correlated to the BMI and body fat mass. Future studies are needed to establish the outcomes achieved with more frequent dosing in obese individuals with primary immunodeficiency.

Waste audits in healthcare: A systematic review and description of best practices

Healthcare generates large amounts of waste, harming both environmental and human health. Waste audits are the standard method for measuring and characterizing waste. This is a systematic review of healthcare waste audits, describing their methods and informing more standardized auditing and reporting. Using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we searched MEDLINE, Embase, Inspec, Scopus and Web of Science Core Collection databases for published studies involving direct measurement of waste in medical facilities. We screened 2398 studies, identifying 156 studies for inclusion from 37 countries. Most were conducted to improve local waste sorting policies or practices, with fewer to inform policy development, increase waste diversion or reduce costs. Measurement was quantified mostly by weighing waste, with many also counting items or using interviews or surveys to compile data. Studies spanned single procedures, departments and hospitals, and multiple hospitals or health systems. Waste categories varied, with most including municipal solid waste or biohazardous waste, and others including sharps, recycling and other wastes. There were significant differences in methods and results between high- and low-income countries. The number of healthcare waste audits published has been increasing, with variable quality and general methodologic inconsistency. A greater emphasis on consistent performance and reporting standards would improve the quality, comparability and usefulness of healthcare waste audits.

Immunoglobulin replacement in hematological malignancies: a focus on evidence, alternatives, dosing strategy, and cessation rule

Acquired hypogammaglobulinemia or secondary immunodeficiency (SID) occurs commonly in hematological malignancies with increasing incidence and complexity in the era of modern therapies. Despite current practice of immunoglobulin replacement (IgRT) in SID, the evidence is lacking, especially for newer treatments. We discuss the current evidence for IgRT in various disease groups including issues, such as actual or ideal body weight (IBW)-based dosing, length of treatment, antibiotic prophylaxis, and vaccination. Incidence of SID with newer treatment is lacking. While there is a trend toward decreased respiratory infections and hospitalizations with IgRT, this is not consistent across all disease course or treatment groups. Dosing and indications for cessation of IgRT are also inadequately characterized. Further randomized controlled trials (RCTs) and observational studies are required to assess the optimal indications, timing, and duration of IgRT to improve the efficacy, safety, and cost-effectiveness. Assessment of alternative and adjunctive therapies, such as vaccination and antibiotic prophylaxis could also improve the outcomes and costs.

A call for transplant stewardship: The need for expanded evidence-based evaluation of induction and biologic-based cost-saving strategies in kidney transplantation and beyond

Rising expenditures threaten healthcare sustainability. While transplant programs are typically considered profitable, transplant medications are expensive and frequently targeted for cost savings. This review aims to summarize available literature supporting cost-containment strategies used in solid organ transplant. Despite widespread use of these tactics, we found the available evidence to be fairly low quality. Strategies mainly focus on induction, particularly rabbit antithymocyte globulin (rATG), given its significant cost and the lack of consensus surrounding dosing. While there is higher-quality evidence for high single-dose rATG, and dose-rounding protocols to reduce waste are likely low risk, more aggressive strategies, such as dosing rATG by CD3+ target-attainment or on ideal-body-weight, have less robust support and did not always attain similar efficacy outcomes. Extrapolation of induction dosing strategies to rejection treatment is not supported by any currently available literature. Cost-saving strategies for supportive therapies, such as IVIG and rituximab also have minimal literature support. Deferral of high-cost agents to the outpatient arena is associated with minimal risk and increases reimbursement, although may increase complexity and cost-burden for patients and infusion centers. The available evidence highlights the need for evaluation of unique patient-specific clinical scenarios and optimization of therapies, rather than simple blanket application of cost-saving initiatives in the transplant population.