The paradigm of hematological malignant versus non-malignant manifestations, driven by primary immunodeficiencies: a complex interplay

A Nationwide Study of the Delayed Diagnosis and the Clinical Manifestations of Predominantly Antibody Deficiencies and CTLA4-Mediated Immune Dysregulation Syndrome in Greece

Background and Objectives: Predominantly antibody deficiencies (PAD) represent the most common type of primary immunodeficiencies in humans, characterized by a wide variation in disease onset, clinical manifestations, and outcome. Considering that the prevalence of PAD in Greece is unknown, and there is limited knowledge on the clinical and laboratory characteristics of affected patients, we conducted a nationwide study. Materials and Methods: 153 patients (male/female: 66/87; median age: 43.0 years; range: 7.0-77.0) diagnosed, and followed-up between August 1979 to September 2023. Furthermore, we classified our cohort into five groups according to their medical history, immunoglobulin levels, and CTLA4-mutational status: 123 had common variable immunodeficiency (CVID), 12 patients with "secondary" hypogammaglobulinemia due to a previous B-cell depletion immunotherapy for autoimmune or malignant disease several years ago (median: 9 years, range 6-14) displaying a typical CVID phenotype, 7 with combined IgA and IgG subclass deficiencies, 5 patients with CVID-like disease due to CTLA4-mediated immune dysregulation syndrome, and 6 patients with unclassified hypogammaglobulinemia. Results: We demonstrated a remarkable delay in PAD diagnosis, several years after the onset of related symptoms (median: 9.0 years, range: 0-43.0). A family history of PAD was only present in 11.8%, with the majority of patients considered sporadic cases. Most patients were diagnosed in the context of a diagnostic work-up for recurrent infections, or recurrent/resistant autoimmune cytopenias. Interestingly, 10 patients (5.6%) had no history of infection, diagnosed due to either recurrent/resistant autoimmunity, or during a work-up of their medical/family history. Remarkable findings included an increased prevalence of lymphoproliferation (60.1%), while 39 patients (25.5%) developed bronchiectasis, and 16 (10.5%) granulomatous disease. Cancer was a common complication in our cohort (25 patients, 16.3%), with B-cell malignancies representing the most common neoplasms (56.7%). Conclusion: Our findings indicate the necessity of awareness about PAD and their complications, aiming for early diagnosis and the appropriate management of affected patients.

Malignancy-associated immune responses: Lessons from human inborn errors of immunity

It is widely understood that cancer is a significant cause of morbidity and mortality worldwide. Despite numerous available treatments, prognosis for many remains poor, thus, the development of novel therapies remains essential. Given the incredible success of many immunotherapies in this field, the important contribution of the immune system to the control, and elimination, of malignancy is clear. While many immunotherapies target higher-order pathways, for example, through promoting T-cell activation via immune checkpoint blockade, the potential to target specific immunological pathways is largely not well researched. Precisely understanding how immunity can be tailored to respond to specific challenges is an exciting idea with great potential, and may trigger the development of new therapies for cancer. Inborn Errors of Immunity (IEI) are a group of rare congenital disorders caused by gene mutations that result in immune dysregulation. This heterogeneous group, spanning widespread, multisystem immunopathology to specific immune cell defects, primarily manifest in immunodeficiency symptoms. Thus, these patients are particularly susceptible to life-threatening infection, autoimmunity and malignancy, making IEI an especially complex group of diseases. While precise mechanisms of IEI-induced malignancy have not yet been fully elucidated, analysis of these conditions can highlight the importance of particular genes, and downstream immune responses, in carcinogenesis and may help inform mechanisms which can be utilised in novel immunotherapies. In this review, we examine the links between IEIs and cancer, establishing potential connections between immune dysfunction and malignancy and suggesting roles for specific immunological mechanisms involved in preventing carcinogenesis, thus, guiding essential future research focused on cancer immunotherapy and providing valuable insight into the workings of the immune system in both health and disease.

Treatment of inborn errors of immunity patients with inflammatory bowel disease phenotype by allogeneic stem cell transplantation

Patients with inborn errors of immunity (IEI) can suffer from treatment-refractory inflammatory bowel disease (IBD) causing failure to thrive and consequences of long-term multiple immunosuppressive treatments. Allogeneic haematopoietic stem cell transplantation (alloHSCT) can serve as a curative treatment option. In this single-centre retrospective cohort study we report on 11 paediatric and young adult IEI patients with IBD and failure to thrive, who had exhausted symptomatic treatment options and received alloHSCT. The cohort included chronic granulomatous disease (CGD), lipopolysaccharide-responsive and beige-like anchor protein (LRBA) deficiency, STAT3 gain-of-function (GOF), Wiskott-Aldrich syndrome (WAS), dedicator of cytokinesis 8 (DOCK8) deficiency and one patient without genetic diagnosis. All patients achieved stable engraftment and immune reconstitution, and gastrointestinal symptoms were resolved after alloHSCT. The overall survival was 11/11 over a median follow-up of 34.7 months. Graft-versus-host disease (GVHD) was limited to grade I-II acute GVHD (n = 5), one case of grade IV acute GVHD and one case of limited chronic GVHD. Since treatment recommendations are limited, this work provides a centre-specific approach to treatment prior to transplant as well as conditioning in IEI patients with severe IBD.

[Combined immunodeficiency due to DOCK8 deficiency. State of the art]

Combinedimmunodeficiency (CID) due to DOCK8 deficiency is an inborn error of immunity (IBD) characterized by dysfunctional T and B lymphocytes; The spectrum of manifestations includes allergy, autoimmunity, inflammation, predisposition to cancer, and recurrent infections. DOCK8 deficiency can be distinguished from other CIDs or within the spectrum of hyper-IgE syndromes by exhibiting profound susceptibility to viral skin infections, associated skin cancers, and severe food allergies. The 9p24.3 subtelomeric locus where DOCK8 is located includes numerous repetitive sequence elements that predispose to the generation of large germline deletions and recombination-mediated somatic DNA repair. Residual production DOCK8 protein contributes to the variable phenotype of the disease. Severe viral skin infections and varicella-zoster virus (VZV)-associated vasculopathy, reflect an essential role of the DOCK8 protein, which is required to maintain lymphocyte integrity as cells migrate through the tissues. Loss of DOCK8 causes immune deficiencies through other mechanisms, including a cell survival defect. In addition, there are alterations in the response of dendritic cells, which explains susceptibility to virus infection and regulatory T lymphocytes that could help explain autoimmunity in patients. Hematopoietic stem cell transplantation (HSCT) is the only curative treatment; it improves eczema, allergies, and susceptibility to infections.

The natural history of ataxia-telangiectasia (A-T): A systematic review

BACKGROUND

Ataxia-telangiectasia is an autosomal recessive, multi-system, and life-shortening disease caused by mutations in the ataxia-telangiectasia mutated gene. Although widely reported, there are no studies that give a comprehensive picture of this intriguing condition.

OBJECTIVES

Understand the natural history of ataxia-telangiectasia (A-T), as reported in scientific literature.

SEARCH METHODS

107 search terms were identified and divided into 17 searches. Each search was performed in PubMed, Ovid SP (MEDLINE) 1946-present, OVID EMBASE 1980 -present, Web of Science core collection, Elsevier Scopus, and Cochrane Library.

SELECTION CRITERIA

All human studies that report any aspect of A-T.

DATA COLLECTION AND ANALYSIS

Search results were de-duplicated, data extracted (including author, publication year, country of origin, study design, population, participant characteristics, and clinical features). Quality of case-control and cohort studies was assessed by the Newcastle-Ottawa tool. Findings are reported descriptively and where possible data collated to report median (interquartile range, range) of outcomes of interest.

MAIN RESULTS

1314 cases reported 2134 presenting symptoms. The most common presenting symptom was abnormal gait (1160 cases; 188 studies) followed by recurrent infections in classical ataxia-telangiectasia and movement disorders in variant ataxia-telangiectasia. 687 cases reported 752 causes of death among which malignancy was the most frequently reported cause. Median (IQR, range) age of death (n = 294) was 14 years 0 months (10 years 0 months to 23 years 3 months, 1 year 3 months to 76 years 0 months).

CONCLUSIONS

This review demonstrates the multi-system involvement in A-T, confirms that neurological symptoms are the most frequent presenting features in classical A-T but variants have diverse manifestations. We found that most individuals with A-T have life limited to teenage or early adulthood. Predominance of case reports, and case series demonstrate the lack of robust evidence to determine the natural history of A-T. We recommend population-based studies to fill this evidence gap.