Agammaglobulinemia: Epidemiology, Pathogenesis, Clinical Phenotype, Diagnosis, Prognosis and Management.

Agammaglobulinemia is a type of primary antibody deficiencies, characterized by severe reduction in serum level of all types of immunoglobulins level and absence of B cells in the peripheral blood. X-linked and various autosomal recessive/dominant mutations have been identified underlying the pathogenesis of this disorder. Affected patients present a broad range of clinical manifestations, including respiratory infections, gastrointestinal complications, Enterovirus infections, autoimmunity, and malignancies. This disease can be controlled by different therapeutic strategies. In this review, we describe different aspects of agammaglobulinemia such as epidemiology, pathogenesis, clinical phenotype, diagnosis, management, and prognosis of congenital agammaglobulinemia.

Direct and Indirect Costs of Immunoglobulin Replacement Therapy in Patients with Common Variable Immunodeficiency (CVID) and X-Linked Agammaglobulinemia (XLA) in Italy.

BACKGROUND: In Italy, there is scarce evidence on the epidemiological and economic burden induced by primary antibody deficiencies. OBJECTIVE: The aim of this study was to elaborate the available epidemiological and cost data in order to estimate the annual expenditure induced by the management of patients affected by the common variable immunodeficiency (CVID) and X-linked agammaglobulinemia (XLA) requiring immunoglobulin (Ig) replacement therapy. METHODS: A probabilistic cost-of-illness model was developed to estimate the number of patients with CVID and XLA, and the economic burden associated with their therapy in terms of direct or indirect costs. A systematic literature review was carried out to reveal both epidemiological and economic data. Furthermore, a probabilistic sensitivity analysis with 5000 Monte Carlo simulations was performed. RESULTS: The epidemiological model allowed us to estimate the number of prevalent patients affected by XLA and CVID in Italy in 2017, corresponding to 1885 (95% confidence interval [CI] 944-3145) and 133 (95% CI 115-152) patients, respectively. The estimated total expenditure for the treatment and management of patients with CVID and XLA requiring Ig replacement therapy amounts to €42.68 million (95% CI €14.38-€86.1 million). CONCLUSIONS: This information provides a comprehensive perspective of the economic issues, and facilitates better-informed public health decision making, in the management of CVID and XLA in Italy.

Investigating the Effectiveness, Acceptability and Impact on Healthcare Usage of Providing a Cognitive-Behavioural Based Psychological Therapy Service for Patients with Primary Antibody Deficiency.

PURPOSE: Patients with primary antibody deficiency report poorer quality of life and higher rates of anxiety and depression than the general population. Cognitive-behavioral therapy has been shown to be a valuable treatment for patients with other long-term physical health conditions, improving well-being and enabling them to manage their symptoms more effectively. The aim of this project was to establish the feasibility and effectiveness of providing cognitive-behavioral based therapy to patients with primary antibody deficiency. METHODS: Forty-four patients completed a course of psychological therapy. Participants completed a series of self-report measures examining psychological and physical health, and service usage, prior to starting treatment and following their final session. They also provided feedback on their experience of treatment. RESULTS: Patients showed improvements in anxiety, depression, insomnia and fatigue. There was a high level of acceptability of the service and the potential for long-term cost savings to the NHS. CONCLUSION: Psychological therapy based on the cognitive-behavioral model of treatment appears to be a valuable treatment for patients with primary antibody deficiency and comorbid mental health difficulties.

Modeling primary immunodeficiency disease epidemiology and its treatment to estimate latent therapeutic demand for immunoglobulin.

PURPOSE: Estimating the underlying demand for immunoglobulin (Ig) is important to ensure that adequate provision is made for patients with primary immune deficiency (PID) in the context of the competing demands for Ig and to ensure optimal therapeutic regimens. The concept of latent therapeutic demand (LTD) was used to estimate evidence-based requirements and compared to the actual Ig consumption in different countries. The estimates were performed for common variable immunodeficiency (CVID) and X-linked Agammaglobulinaemia (XLA), the two most commonly studied PIDs using Ig. METHODS: The LTD model for CVID and XLA was derived using decision analysis methodology. Data for the epidemiology and treatment variables were obtained from peer-reviewed publications, clinical registries and publicly-available patient surveys. Incomplete data records from registries were excluded from analysis. The variables impacting LTD were ranked in order of sensitivity through a tornado diagram. The uncertainty surrounding the variables was modeled using probabilistic distributions and evaluated using Monte Carlo simulation. RESULTS: Treatment dosage and prevalence were determined to be the most sensitive variables driving demand. The average potential usage of Ig for the treatment of CVID and XLA was estimated at 72 g per 1,000 population, which is higher than the estimated Ig usage in CVID and XLA of 27-41 g per 1,000 population in the US. CONCLUSION: The potential demand for treating CVID and XLA exceeds the currently observed usage of Ig in these disorders. Variable usage in different countries is due to varying prevalence and dosage practices. Under-reporting in patient registries represents a major obstacle to calculating the true prevalence of CVID and XLA. Modeling demand relies heavily upon accurate prevalence and practice estimates which reemphasize the importance of accurate registries and improved registry methods. As better data becomes available, revision of model variables provides opportunities to anticipate and prepare for evolving patient needs.