An appraisal of the frequency and severity of non-infectious manifestations in primary immunodeficiencies. A study of a national retrospective cohort of 1375 patients over 10 years

Multidisciplinary approach to treating complex immune dysregulation disorders: an adaptive model for institutional implementation

Patients with immune dysregulation may present with varying combinations of autoimmunity, autoinflammation, immunodeficiency, atopy, lymphoproliferation, and/or malignancy, often with multisystem involvement. Recognizing specific patterns of immune dysregulation, coordinating and interpreting complex diagnostic testing, and choosing initial (often empiric) treatment can be challenging. Centers are increasingly assembling multidisciplinary teams (MDTs) to standardize evaluation and optimize treatment of patients with complex immune dysregulation (immune dysregulation MDTs [immMDTs]). However, published information on the composition and function of immMDTs is sparse, and there is little guidance for those seeking to establish or optimize an immMDT. To inform this review, we assembled a panel of 24 pediatric providers from multiple specialties who actively participate in immMDTs to provide expert opinion. We also conducted a search of the available information on pediatric immMDTs from PubMed. Based on these insights, we summarize the structure and function of active immMDTs across the United States and focus on best practices and context-dependent solutions that may enable institutions with varying goals, patient populations, and resources to establish an immMDT.

Update on inborn errors of immunity

Ever since the first description of an inherited immunodeficiency in 1952 in a boy with gammaglobulin deficiency, new insights have progressed rapidly in disorders that are now referred to as inborn errors of immunity. In a field where fundamental molecular biology, genetics, immune signaling, and clinical care are tightly intertwined, 2022-24 saw a multitude of advances. Here we report a selection of research updates with a main focus on (1) diagnosis and screening, (2) new genetic defects, (3) susceptibility to severe coronavirus disease 2019 infection and impact of vaccination, and (4) treatment. Importantly, new pathogenic insights more rapidly affect treatment outcomes, either through an earlier and more precise diagnosis or through implementation of novel, personalized treatment. The field is growing rapidly, so awareness, communication, and collaboration are key to improving treatment outcomes.

Healthcare resource utilization and costs in immunodeficient patients receiving subcutaneous Ig: Real-world evidence from France

BACKGROUND

Subcutaneous immunoglobulin (SCIg) replacement therapy is indicated for patients with hypogammaglobulinemia caused by primary (PID) and secondary immunodeficiencies (SID).

OBJECTIVE

To compare healthcare resource utilization (HCRU) and related direct medical costs of patients in France treated with weekly conventional SCIg (cSCIg) vs monthly hyaluronidase-facilitated SCIg (fSCIg).

METHODS

This retrospective study of Ig-naïve patients with PID or SID newly receiving a SCIg between 2016 and 2018, extracted from the French National Healthcare reimbursement database (SNDS), analyzed the SCIg-related HCRU and reimbursed costs generated from in-hospital (hospitalizations and SCIg doses) or at-home (nurse visits [NV] and pump provider visits [PPV], drug doses) SCIg administration.

RESULTS

Overall, 2,012 patients (PID:534; SID:1,478) were analyzed. The follow-up duration varied between 7.5 and 8.7 months according to sub-groups. Compared with fSCIg-treated patients, monthly mean rates of NV and PPV were respectively 2.5 and 3.1 times higher in PID, and 1.6 and 3.1 times higher in SID cSCIg-treated patients. Monthly mean rates for SCIg administration-related hospitalizations were lower overall, while their costs were 1.6 and 1.8 times higher for cSCIg than fSCIg subgroups, in PIDs and SIDs respectively; these results are due to more frequent hospitalizations with fSCIg being mainly shorter, without stayover. Total HCRU costs from the French NHI's perspective were estimated to be lower with fSCIg vs cSCIg, in PIDs and SIDs.

CONCLUSION

This study provides real-world evidence of SCIg administration in a large French population. Patients with PID or SID treated with fSCIg had fewer at-home HCRU and lower overall costs for in-hospital or at-home SCIg administration compared with cSCIg-treated patients.

Sequelae of B-Cell Depleting Therapy: An Immunologist's Perspective

B-cell depleting therapy (BCDT) has revolutionised the treatment of B-cell malignancies and autoimmune diseases by targeting specific B-cell surface antigens, receptors, ligands, and signalling pathways. This narrative review explores the mechanisms, applications, and complications of BCDT, focusing on the therapeutic advancements since the introduction of rituximab in 1997. Various monoclonal antibodies and kinase inhibitors are examined for their roles in depleting B cells through antibody-dependent and independent mechanisms. The off-target effects, such as hypogammaglobulinemia, infections, and cytokine release syndrome, are discussed, emphasising the need for immunologists to identify and help manage these complications. The increasing prevalence of BCDT has necessitated the involvement of clinical immunologists in addressing treatment-associated immunological abnormalities, including persistent hypogammaglobulinemia and neutropenia. We highlight the importance of considering underlying inborn errors of immunity (IEI) in patients presenting with these complications. Furthermore, we discuss the impact of BCDT on other immune cell populations and the challenges in predicting and managing long-term immunological sequelae. The potential for novel BCDT agents targeting the BAFF/APRIL-TACI/BCMA axis and B-cell receptor signalling pathways to treat autoimmune disorders is also explored, underscoring the rapidly evolving landscape of B-cell targeted therapies.

Protective role of antibodies in enteric virus infections: Lessons from primary and secondary immune deficiencies

Enteric viruses are the main cause of acute gastroenteritis worldwide with a significant morbidity and mortality, especially among children and aged adults. Some enteric viruses also cause disseminated infections and severe neurological manifestations such as poliomyelitis. Protective immunity against these viruses is not well understood in humans, with most knowledge coming from animal models, although the development of poliovirus and rotavirus vaccines has extended our knowledge. In a classical view, innate immunity involves the recognition of foreign DNA or RNA by pathogen recognition receptors leading to the production of interferons and other inflammatory cytokines. Antigen uptake and presentation to T cells and B cells then activate adaptive immunity and, in the case of the mucosal immunity, induce the secretion of dimeric IgA, the more potent immunoglobulins in viral neutralization. The study of Inborn errors of immunity (IEIs) offers a natural opportunity to study nonredundant immunity toward pathogens. In the case of enteric viruses, patients with a defective production of antibodies are at risk of developing neurological complications. Moreover, a recent description of patients with low or absent antibody production with protracted enteric viral infections associated with hepatitis reinforces the prominent role of B cells and immunoglobulins in the control of enteric virus.

Health Care Utilisation in a Cohort of Patients with Primary and Secondary Antibody Deficiency in the United Kingdom

INTRODUCTION

This study investigates the frequency of hospital attendances, emergency care attendances and geographical influences on service interaction in cohorts of patients with primary and secondary antibody deficiency, to inform future service planning and delivery.

METHODS

The COVID-19 in Antibody Deficiency (COV-AD) study was a United Kingdom study that enrolled 525 participants between April 2021 and September 2022. Data on health care utilisation was extracted from a screening cohort of participants at one participating site (Birmingham, UK). Hospital attendance (i.e. all outpatient and inpatient care episodes, including hospital-based IVIG treatment) and emergency care attendance patterns were analysed. Geographical differences in travel times to hospitals and associated costs were considered for all participants at all recruiting sites.

RESULTS

Individuals with antibody deficiency had a median of 7 hospital attendances per year. A diagnosis of secondary antibody deficiency, and antibody deficiency severe enough to require treatment with immunoglobulin replacement were associated with an increased frequency of hospital attendance. 12.7% of the cohort attended the Emergency Department at least once in the preceding twelve months. Individuals with secondary antibody deficiency were at greater risk of requiring emergency care over the preceding one-year and five-year periods. Individuals receiving subcutaneous immunoglobulin lived further from their local immunology centre and were more likely to engage with the COV-AD research study remotely, via dried blood spots sampling.

CONCLUSION

This study highlights the utilisation of emergency and secondary care usage amongst patient with immunodeficiency and may inform service adaptation and development to better accommodate patient needs and circumstances.

Pitfalls in time-to-event analysis of registry data: a tutorial based on simulated and real cases

Survival analysis (also referred to as time-to-event analysis) is the study of the time elapsed from a starting date to some event of interest. In practice, these analyses can be challenging and, if methodological errors are to be avoided, require the application of appropriate techniques. By using simulations and real-life data based on the French national registry of patients with primary immunodeficiencies (CEREDIH), we sought to highlight the basic elements that need to be handled correctly when performing the initial steps in a survival analysis. We focused on non-parametric methods to deal with right censoring, left truncation, competing risks, and recurrent events. Our simulations show that ignoring these aspects induces a bias in the results; we then explain how to analyze the data correctly in these situations using non-parametric methods. Rare disease registries are extremely valuable in medical research. We discuss the application of appropriate methods for the analysis of time-to-event from the CEREDIH registry. The objective of this tutorial article is to provide clinicians and healthcare professionals with better knowledge of the issues facing them when analyzing time-to-event data.

Clinical, Radiologic, and Immunologic Features of Patients With CTLA4 Deficiency With Neurologic Involvement

OBJECTIVES

CTLA4 deficiency (CTLA4d) is a disease with multisystem autoimmune features, including neurologic manifestations. We aimed to describe neurologic involvement in these patients.

METHODS

We performed a cross-sectional observational study using the French Reference Centre for Primary Immunodeficiencies (CEREDIH) registry plus a surveillance in national society networks. Participants with confirmed CTLA4d and neurologic involvement were included. Clinical, laboratory, and radiologic features were collected, as well as treatments. Available MRI was double-reviewed.

RESULTS

Among 70 patients with CTLA4d, 13 patients (21%) had neurologic involvement. Neurologic symptoms began at a median age of 18 [15-45] years, mostly occurring after systemic manifestations (median delay: 8.5 [4.5-10.5] years). Main symptoms included headaches, focal deficit (54% each), and seizures (38%). MRI detected at least 1 large contrast-enhancing lesion in 8 patients. Lesions reminiscent of multiple sclerosis lesions were found in 6 patients. Cerebellar (6 patients) and large spinal cord lesions (3 patients) were common. Ten patients were treated with abatacept, of whom 9 (90%) showed good clinical and radiologic response.

DISCUSSION

Neurologic involvement is common among patients with CTLA4d. Despite its rarity, and considering the suspected efficacy of abatacept, neurologists should be aware of the characteristics of CTLA4d neurologic involvement.

The PID Odyssey 2030: outlooks, unmet needs, hurdles, and opportunities - proceedings from the IPOPI global multi-stakeholders' summit (June 2022)

IPOPI held its first Global Multi-Stakeholders' Summit on 23-24 June 2022 in Cascais, Portugal. This IPOPI initiative was designed to set the stage for a stimulating forward-thinking meeting and brainstorming discussion among stakeholders on the future priorities of the PID community. All participants were actively engaged in the entire Summit, bringing provocative questions to ensure a high level of discussion and engagement, and partnered in identifying the outlooks, unmet needs, hurdles and opportunities of PIDs for 2030. The topics that were covered include diagnosis (e.g., newborn screening [NBS], genomic sequencing- including ethical aspects on the application of genomics on NBS, the role of more accurate and timely diagnostics in impacting personalized management), treatment (e.g., the therapeutic evolution of immunoglobulins in a global environment, new therapies such as targeted therapies, new approaches in curative therapies), the interactions of Primary ID with Secondary ID, Autoinflammatory Diseases and other diseases as the field experiences an incessant evolution, and also the avenues for research in the field of humanities and human sciences such as Patient-Reported Outcome Measures (PROMs), Patient-Reported Experience Measures (PREMs), and Health-Related Quality Of Life (HRQoL). During this meeting, all participants contributed to the drafting of recommendations based on our common understanding of the future opportunities, challenges, and scenarios. As a collection of materials, perspectives and summaries, they are succinct and impactful and may help determine some of the next key steps for the PID community.

Autoimmune and autoinflammatory manifestations in inborn errors of immunity

PURPOSE OF REVIEW

Autoimmune and inflammatory complications have been shown to arise in all age groups and across the spectrum of inborn errors of immunity (IEI). This review aims to highlight recent ground-breaking research and its impact on our understanding of IEI.

RECENT FINDINGS

Three registry-based studies of unprecedented size revealed the high prevalence of autoimmune, inflammatory and malignant complications in IEI. Two novel IEI were discovered: an autoinflammatory relopathy, cleavage-resistant RIPK1-induced autoinflammatory syndrome, as well as an inheritable phenocopy of PD-1 blockade-associated complication (as seen in cancer therapy) manifesting with multiorgan autoimmunity and Mycobacterium tuberculosis infection. A study examining patients with partial RAG deficiency pinpointed the specific defects leading to the failure of central and peripheral tolerance resulting in wide-ranging autoimmunity. A novel variant of Immunodeficiency Polyendocrinopathy Enteropathy X-linked syndrome was described, associated with preferential expression of a FOXP3 isoform lacking exon 2, linking exon-specific functions and the phenotypes corresponding to their absence. Lastly, we touch on recent findings pertaining actinopathies, the prototypical IEI with autoimmune, inflammatory and atopic complications.

SUMMARY

Dysregulated immunity has been associated with IEI since their discovery. Recently, large concerted efforts have shown how common these complications actually are while providing insight into normal and dysregulated molecular mechanisms, as well as describing novel diseases.

Eosinophilic gastrointestinal disorders in patients with inborn errors of immunity: Data from the USIDNET registry

Rationale

Eosinophilic gastrointestinal disorders (EGID), including eosinophilic esophagitis (EoE), are inflammatory disorders of the gastrointestinal mucosa mediated by complex immune mechanisms. Although there have been initial reports of EGID in patients with inborn errors of immunity (IEI), little is known about the presentation of EGID in immunodeficient individuals.

Methods

We queried the U.S. Immunodeficiency Network (USIDNET) for patient records including the terms eosinophilic esophagitis, gastritis, enteritis, or colitis. We analyzed 74 patient records from the database, including diagnoses, demographics, infectious history, laboratory findings, genetic studies, therapeutic interventions, and clinical outcomes.

Results

We examined 74 patient records. A total of 61 patients had isolated EoE, and 13 had distal gastrointestinal involvement consistent with EGID. The most common IEI were common variable immunodeficiency (43.2%), some form of combined immunodeficiency (21.6%), chronic granulomatous disease (8.1%), hyper-IgE syndrome (6.8%), and autoimmune lymphoproliferative syndrome (6.8%). The median age at presentation with IEI was 0.5 years (IQR 1.725, max 39 years) and 56.76% were male. Approximately 20% of the patients in the cohort received a hematopoietic stem cell transplantation for treatment of IEI, but the timing of the HSCT in relationship to the EGID diagnosis was unknown.

Conclusions

Here, we report EGID in a diverse cohort of IEI patients, suggesting that both non-EoE EGID and EoE can be seen as comorbid conditions with a variety of IEI. Our data suggests that EGID may be more common in patients with IEI than would be expected based on estimates of EGID in the general population.