Primary immunodeficiencies in the Netherlands: national patient data demonstrate the increased risk of malignancy

Inborn errors of immunity and its clinical significance in children with lymphoma in China: a single-center study

OBJECTIVE

To investigate the incidence, clinical and genetic characteristics of pediatric lymphoma patients of China with inborn errors of immunity (IEI)-related gene mutations, which have not been fully studied.

METHOD

From Jan. 2020 to Mar. 2023, IEI-related genetic mutations were retrospectively explored in 108 children with lymphomas admitted to Beijing Children's Hospital by NGS. Genetic rule and clinical characteristics as well as treatment outcomes were compared between patients with or without IEI-related gene mutations.

RESULTS

A total of 17 patients (15.7 %) harbored IEI-associated mutations, including 4 cases with X-linked lymphoproliferative syndrome (XLP), 3 cases had mutations in tumor necrosis factor receptor superfamily 13B (TNFRSF13B), 2 cases with Activated p110 syndrome (APDS). Patients with IEI all had alteration of immunocompetence with decreased levels of immunoglobulin and lymphocyte subsets. Recurrent infection existed in 41.2 % of patients. The 18-month event-free survival (EFS) and the overall response rate (ORR) of patients with IEI are significantly lower than those without IEI (33.86% vs. 73.26 %, p = 0.011; 52.94% vs. 87.91 %, p = 0.002, respectively). In addition, patients with IEI had a higher progression disease (PD) rate of 23.5 % than those without IEI of 4.4 % (p = 0.006).

CONCLUSION

The present study demonstrated that IEI-associated lymphomas were much more common than originally appreciated in pediatric lymphomas, and those were insensitive to treatment and more likely to progress or relapse. The genomic analysis and a thorough review of the medical history of IEI can be used to distinguish them from pediatric lymphomas without IEI, which are beneficial for the early diagnosis and direct intervention.

Cancer Prevalence in Children with Inborn Errors of Immunity: Report from a Single Institution

BACKGROUND

Inborn Errors of Immunity (IEI) comprise several genetic anomalies that affect different components of the innate and adaptive responses, predisposing to infectious diseases, autoimmunity and malignancy. Different studies, mostly in adults, have reported a higher prevalence of cancer in IEI patients. However, in part due to the rarity of most of these IEI subtypes (classified in ten categories by the Primary Immunodeficiency Committee of the International Union of Immunological Societies), it is difficult to assess the risk in a large number of patients, especially during childhood.

OBJECTIVE

To document the cancer prevalence in a pediatric cohort from a single referral institution, assessing their risk, together with the type of neoplasia within each IEI subgroup.

METHOD

An extensive review of clinical records from 1989 to 2022 of IEI patients who at some point developed cancer before the age of sixteen.

RESULTS

Of a total of 1642 patients with IEI diagnosis, 34 developed cancer before 16 years of age, showing a prevalence (2.1%) significantly higher than that of the general age matched population (0.22). Hematologic neoplasms (mostly lymphomas) were the most frequent malignancies.

CONCLUSION

This study represents one of the few reports focused exclusively in pediatric IEI cases, describing not only the increased risk of developing malignancy compared with the age matched general population (a fact that must be taken into account by immunologists during follow-up) but also the association of the different neoplasms with particular IEI subtypes, thus disclosing the possible mechanisms involved.

Malignancies and Lymphoproliferations in Children With Primary Immune Deficiency-A Single-center Experience

Primary immune deficiencies (PIDs) are rare genetic disorders characterized by impaired immune function, leading to frequent infections and immune dysregulation. Studies have shown that individuals with PID are at an increased risk of developing malignancies and lymphoproliferative disorders compared with the general population. In this single-center study, we aimed to analyze the occurrence of malignancies and lymphoproliferations in children diagnosed with PID. We retrospectively analyzed the medical records of 550 pediatric patients diagnosed with PIDs at our center. Among them, 17 (3,0%) patients were identified with malignancy and/or benign lymphoproliferation. Eight of the 17 patients (47.0%) had immune dysregulatory diseases, whereas ataxia-telangiectasia was the second most common PID associated with malignancy and/or benign lymphoproliferation (n = 5, 29.4%). Lymphoma was the predominant malignancy (n = 11, 64.7%), and Epstein-Barr virus was identified as the most common viral agent associated with malignancy and/or benign lymphoproliferation in patients with PID (n = 8, 47.0%). Our study highlights the association between PID and malignancies/lymphoproliferations, with immune dysregulation syndromes being the most common subclass associated with malignancies/lymphoproliferations. Early diagnosis, multidisciplinary management, and regular surveillance are crucial in improving patient outcomes and saving lives.

Inborn errors of immunity in adulthood

Inborn errors of immunity (IEIs) are a group of conditions whereby parts of the immune system are missing or dysfunctional. Once thought to primarily be a pediatric disorder, it is now estimated that more than 50% of worldwide incident IEI cases are accounted for by adults. Delayed diagnosis, late symptom onset, and IEI phenocopies can all lead to adult-onset recognition of IEIs. Lack of awareness regarding the diversity of IEI manifestations in adults contributes to diagnostic and treatment delays. Prompt referral to immunology is critical so that patients can receive a precise molecular diagnosis and targeted therapy when available. This article serves as a primer on IEIs in adulthood, highlighting the pathophysiology, epidemiology and clinical features. We present clinical vignettes of three key IEIs to assist clinicians in building illness scripts on their presentations. We provide a framework for the laboratory evaluation of IEIs and their initial treatment, with the aim of improving recognition and management of these conditions.

Immune dysregulation as a leading principle for lymphoma development in diverse immunological backgrounds

Lymphoma is a heterogeneous group of malignancies arising from lymphocytes, which poses a significant challenge in terms of diagnosis and treatment due to its diverse subtypes and underlying mechanisms. This review aims to explore the shared and distinct features of various forms of lymphoma predisposing conditions, with a focus on genetic, immunological and molecular aspects. While diseases such as autoimmune disorders, inborn errors of immunity and iatrogenic immunodeficiencies are biologically and immunologically distinct, each of these diseases results in profound immune dysregulation and a predisposition to lymphoma development. Interestingly, the increased risk is often skewed towards a particular subtype of lymphoma. Patients with inborn errors of immunity in particular present with extreme forms of lymphoma predisposition, providing a unique opportunity to study the underlying mechanisms. External factors such as chronic infections and environmental exposures further modulate the risk of lymphoma development. Common features of conditions predisposing to lymphoma include: persistent inflammation, recurrent DNA damage or malfunctioning DNA repair, impaired tumor surveillance and viral clearance, and dysregulation of fundamental cellular processes such as activation, proliferation and apoptosis. Our growing understanding of the underlying mechanisms of lymphomagenesis provides opportunities for early detection, prevention and tailored treatment of lymphoma development.

Classic Hodgkin lymphoma in young people

Classic Hodgkin lymphoma (CHL) is a unique form of lymphoid cancer featuring a heterogeneous tumor microenvironment and a relative paucity of malignant Hodgkin and Reed-Sternberg (HRS) cells with characteristic phenotype. Younger individuals (children, adolescents and young adults) are affected as often as the elderly, producing a peculiar bimodal age-incidence profile that has generated immense interest in this disease and its origins. Decades of epidemiological investigations have documented the populations most susceptible and identified multiple risk factors that can be broadly categorized as either biological or environmental in nature. Most risk factors result in overt immunodeficiency or confer more subtle alterations to baseline health, physiology or immune function. Epstein Barr virus, however, is both a risk factor and well-established driver of lymphomagenesis in a significant subset of cases. Epigenetic changes, along with the accumulation of somatic driver mutations and cytogenetic abnormalities are required for the malignant transformation of germinal center-experienced HRS cell precursors. Chromosomal instability and the influence of endogenous mutational processes are critical in this regard, by impacting genes involved in key signaling pathways that promote the survival and proliferation of HRS cells and their escape from immune destruction. Here we review the principal features, known risk factors and lymphomagenic mechanisms relevant to newly diagnosed CHL, with an emphasis on those most applicable to young people.

Allogeneic Hematopoietic Stem Cell Transplantation Activity in Inborn Errors of Immunity in Russian Federation

PURPOSE

Allogeneic hematopoietic stem cell transplantation (HSCT) is an established therapy for many inborn errors of immunity (IEI). The indications for HSCT have expanded over the last decade. The study aimed to collect and analyze the data on HSCT activity in IEI in Russia.

METHODS

The data were collected from the Russian Primary Immunodeficiency Registry and complemented with information from five Russian pediatric transplant centers. Patients diagnosed with IEI by the age of 18 years and who received allogeneic HSCT by the end of 2020 were included.

RESULTS

From 1997 to 2020, 454 patients with IEI received 514 allogeneic HSCT. The median number of HSCTs per year has risen from 3 in 1997-2009 to 60 in 2015-2020. The most common groups of IEI were immunodeficiency affecting cellular and humoral immunity (26%), combined immunodeficiency with associated/syndromic features (28%), phagocyte defects (21%), and diseases of immune dysregulation (17%). The distribution of IEI diagnosis has changed: before 2012, the majority (65%) had severe combined immunodeficiency (SCID) and hemophagocytic lymphohistiocytosis (HLH), and after 2012, only 24% had SCID and HLH. Of 513 HSCTs, 48.5% were performed from matched-unrelated, 36.5% from mismatched-related (MMRD), and 15% from matched-related donors. In 349 transplants T-cell depletion was used: 325 TCRαβ/CD19+ depletion, 39 post-transplant cyclophosphamide, and 27 other. The proportion of MMRD has risen over the recent years.

CONCLUSION

The practice of HSCT in IEI has been changing in Russia. Expanding indications to HSCT and SCID newborn screening implementation may necessitate additional transplant beds for IEI in Russia.

How to recognize inborn errors of immunity in a child presenting with a malignancy: guidelines for the pediatric hemato-oncologist

Inborn errors of immunity (IEI) are a group of disorders caused by genetically determined defects in the immune system, leading to infections, autoimmunity, autoinflammation and an increased risk of malignancy. In some cases, a malignancy might be the first sign of an underlying IEI. As therapeutic strategies might be different in these patients, recognition of the underlying IEI by the pediatric hemato-oncologist is important. This article, written by a group of experts in pediatric immunology, hemato-oncology, pathology and genetics, aims to provide guidelines for pediatric hemato-oncologists on how to recognize a possible underlying IEI and what diagnostic tests can be performed, and gives some consideration to treatment possibilities.

Genetic Causes, Clinical Features, and Survival of Underlying Inborn Errors of Immunity in Omani Patients: a Single-Center Study

PURPOSE

Early identification of inborn errors of immunity (IEIs) is crucial due to the significant risk of morbidity and mortality. This study aimed to describe the genetic causes, clinical features, and survival rate of IEIs in Omani patients.

METHODS

A prospective study of all Omani patients evaluated for immunodeficiency was conducted over a 17-year period. Clinical features and diagnostic immunological findings were recorded. Targeted gene testing was performed in cases of obvious immunodeficiency. For cases with less conclusive phenotypes, a gene panel was performed, followed by whole-exome sequencing if necessary.

RESULTS

A total of 185 patients were diagnosed with IEIs during the study period; of these, 60.5% were male. Mean ages at symptom onset and diagnosis were 30.0 and 50.5 months, respectively. Consanguinity and a family history of IEIs were present in 86.9% and 50.8%, respectively. Most patients presented with lower respiratory infections (65.9%), followed by growth and development manifestations (43.2%). Phagocytic defects were the most common cause of IEIs (31.9%), followed by combined immunodeficiency (21.1%). Overall, 109 of 132 patients (82.6%) who underwent genetic testing received a genetic diagnosis, while testing was inconclusive for the remaining 23 patients (17.4%). Among patients with established diagnoses, 37 genes and 44 variants were identified. Autosomal recessive inheritance was present in 81.7% of patients with gene defects. Several variants were novel. Intravenous immunoglobulin therapy was administered to 39.4% of patients and 21.6% received hematopoietic stem cell transplantation. The overall survival rate was 75.1%.

CONCLUSION

This study highlights the genetic causes of IEIs in Omani patients. This information may help in the early identification and management of the disease, thereby improving survival and quality of life.

Genomics Driving Diagnosis and Treatment of Inborn Errors of Immunity With Cancer Predisposition

Inborn errors of immunity (IEI) are genetically and clinically heterogeneous disorders that, in addition to infection susceptibility and immune dysregulation, can have an enhanced cancer predisposition. The increasing availability of upfront next-generation sequencing diagnostics in immunology and oncology have uncovered substantial overlap of germline and somatic genetic conditions that can result in immunodeficiency and cancer. However, broad application of unbiased genetics in these neighboring disciplines still needs to be deployed, and joined therapeutic strategies guided by germline and somatic genetic risk factors are lacking. We illustrate the current difficulties encountered in clinical practice, summarize the historical development of pathophysiological concepts of cancer predisposition, and review select genetic, molecular, and cellular mechanisms of well-defined and illustrative disease entities such as DNA repair defects, combined immunodeficiencies with Epstein-Barr virus susceptibility, autoimmune lymphoproliferative syndromes, regulatory T-cell disorders, and defects in cell intrinsic immunity. We review genetic variants that, when present in the germline, cause IEI with cancer predisposition but, when arising as somatic variants, behave as oncogenes and cause specific cancer entities. We finally give examples of small molecular compounds that are developed and studied to target genetically defined cancers but might also proof useful to treat IEI.

The yin and the yang of early classical pathway complement disorders

The classical pathway of the complement cascade has been recognized as a key activation arm, partnering with the lectin activation arm and the alternative pathway to cleave C3 and initiate the assembly of the terminal components. While deficiencies of classical pathway components have been recognized since 1966, only recently have gain-of-function variants been described for some of these proteins. Loss-of-function variants in C1, C4, and C2 are most often associated with lupus and systemic infections with encapsulated bacteria. C3 deficiency varies slightly from this phenotypic class with membranoproliferative glomerulonephritis and infection as the dominant phenotypes. The gain-of- function variants recently described for C1r and C1s lead to periodontal Ehlers Danlos syndrome, a surprisingly structural phenotype. Gain-of-function in C3 and C2 are associated with endothelial manifestations including hemolytic uremic syndrome and vasculitis with C2 gain-of-function variants thus far having been reported in patients with a C3 glomerulopathy. This review will discuss the loss-of-function and gain-of-function phenotypes and place them within the larger context of complement deficiencies.

Inborn Errors of Immunity in Algerian Children and Adults: A Single-Center Experience Over a Period of 13 Years (2008–2021)

Background

Inborn errors of immunity (IEI) predispose patients to various infectious and non-infectious complications. Thanks to the development and expanding use of flow cytometry and increased awareness, the diagnostic rate of IEI has markedly increased in Algeria the last decade.

Aim

This study aimed to describe a large cohort of Algerian patients with probable IEI and to determine their clinical characteristics and outcomes.

Methods

We collected and analyzed retrospectively the demographic data, clinical manifestations, immunologic, genetic data, and outcome of Algerian IEI patients - diagnosed in the department of medical immunology of Beni Messous university hospital center, Algiers, from 2008 to 2021.

Results

Eight hundred and seven patients with IEI (482 males and 325 females) were enrolled, 9.7% of whom were adults. Consanguinity was reported in 50.3% of the cases and a positive family history in 32.34%. The medium age at disease onset was 8 months and at diagnosis was 36 months. The median delay in diagnosis was 16 months. Combined immunodeficiencies were the most frequent (33.8%), followed by antibody deficiencies (24.5%) and well-defined syndromes with immunodeficiency (24%). Among 287 patients tested for genetic disorders, 129 patients carried pathogenic mutations; 102 having biallelic variants mostly in a homozygous state (autosomal recessive disorders). The highest mortality rate was observed in patients with combined immunodeficiency (70.1%), especially in patients with severe combined immunodeficiency (SCID), Omenn syndrome, or Major Histocompatibility Complex (MHC) class II deficiency.

Conclusion

The spectrum of IEI in Algeria is similar to that seen in most countries of the Middle East and North Africa (MENA) region, notably regarding the frequency of autosomal recessive and/or combined immunodeficiencies.

Case Report: A Highly Variable Clinical and Immunological Presentation of IKAROS Deficiency in a Single Family

Here we describe a novel mutation in the IKZF gene encoding IKAROS, as the cause of common variable immunodeficiency (CVID). The identification of the same defect in the IKZF gene with manifestations of asymptomatic selective IgA deficiency and chronic ITP in the father and her younger brother, respectively, demonstrates the large variability of this genetic defect in one single family, while living in the same environment with a relatively similar genetic background. As discussed, clinical penetrance of the molecular defects identified by mutations in IKZF and other common gene defects in CVID in familial immune-related abnormalities makes genetic testing a necessary step for diagnosis, management, and counseling, as part of the routine immunological workup.

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.

Xenograft cancer vaccines prepared from immunodeficient mice increase tumor antigen diversity and host T cell efficiency against colorectal cancers

Autologous cancer vaccines (ACVs) are a desirable approach for personalized medicine, but the efficiency of ACVs remains unsatisfactory due to their low immunogenicity. This study developed a platform that can enhance the immunogenicity of ACVs by transplanting the tumors into immunodeficient mice. The CT26 cell line was inoculated into severe combined immunodeficient mice (SCID) for vaccine preparation where escalates tumor development, subsequently diversifying the tumor antigenic topology. CT26/SCID cancer vaccines significantly inhibited tumor growth, increased the amount of tumor infiltrating lymphocytes, and triggered Th-1 predominant immune responses. Tumor antigenic profiles of CT26/SCID cells were further analyzed by liquid chromatography-tandem mass spectrometry. Compared to CT26 parental cells, a total of 428 differentially expressed proteins (DEPs) were detected. These DEPs revealed that CT26/SCID cells overexpressed several novel therapeutic targets, including KNG1, apoA-I and, β2-GPI, which can trigger cytotoxic T cells towards Th-1 predominant immune responses and directly suppress proliferation in tumors. CT26/SCID cancer vaccines can be easily manufactured, while traits of triggering stronger antigen-specific Th-1 immune activity against tumors, are retained. Results of this study provide an effective proof-of-concept of an ACV for personalized cancer immunotherapy.

Global systematic review of primary immunodeficiency registries

INTRODUCTION

During the last 4 decades, registration of patients with primary immunodeficiencies (PID) has played an essential role in different aspects of these diseases worldwide including epidemiological indexes, policymaking, quality controls of care/life, facilitation of genetic studies and clinical trials as well as improving our understanding about the natural history of the disease and the immune system function. However, due to the limitation of sustainable resources supporting these registries, inconsistency in diagnostic criteria and lack of molecular diagnosis as well as difficulties in the documentation and designing any universal platform, the global perspective of these diseases remains unclear.

AREAS COVERED

Published and unpublished studies from January 1981 to June 2020 were systematically reviewed on PubMed, Web of Science and Scopus. Additionally, the reference list of all studies was hand-searched for additional studies. This effort identified a total of 104614 registered patients and suggests identification of at least 10590 additional PID patients, mainly from countries located in Asia and Africa. Molecular defects in genes known to cause PID were identified and reported in 13852 (13.2% of all registered) patients.

EXPERT OPINION

Although these data suggest some progress in the identification and documentation of PID patients worldwide, achieving the basic requirement for the global PID burden estimation and registration of undiagnosed patients will require more reinforcement of the progress, involving both improved diagnostic facilities and neonatal screening.

Genes Common in Primary Immunodeficiencies and Cancer Display Overrepresentation of Codon CTG and Dominant Role of Selection Pressure in Shaping Codon Usage

Primary immunodeficiencies (PIDs) are disorders of the immune system that involve faulty cellular, humoral, or both cellular and humoral functions. PIDs are present at the crossroad between infections, immune dysregulation, and cancers. A panel encompassing 42 genes involved in both PIDs and cancer has been investigated for the genes’ compositional properties, codon usage patterns, various forces affecting codon choice, protein properties, and gene expression profiles. In the present study, the codon choice of genes was found to be dependent upon the richness of the nucleotide; the viz AT nucleotide rich genome preferred AT ending codons. The dinucleotide TpA adversely affected protein expression, while CpG did not. The CTG codon was the most overrepresented codon in 80.95% of genes. Analysis of various protein properties, including GRAVY, AROMA, isoelectric point, aliphatic index, hydrophobicity, instability index, and numbers of acidic, basic, and neutral amino acid residues revealed that the hydrophobicity index, instability index, and numbers of acidic and basic amino acid residues are the factors affecting gene expression. Based on neutrality analysis, parity analysis, ENc-GC3 analysis, and regression analysis of nucleotides present at the first and third positions of the codon, it was determined that selection pressure, mutation pressure, and compositional constraints all participated in shaping codon usage. The study will help determine the various evolutionary forces acting on genes common to both PIDs and cancer. Codon usage analysis might be helpful in the future to augment both diseases simultaneously. The research also indicates a peculiar pattern adapted by a set of genes involved in any disease.

Altered Spectrum of Lymphoid Neoplasms in a Single-Center Cohort of Common Variable Immunodeficiency with Immune Dysregulation

Purpose

Common variable immune deficiency (CVID) confers an increased risk of lymphoid neoplasms, but reports describing the precise WHO specification of the lymphoma subtypes and their immunological environment are lacking. We therefore classified lymphomas—occurring in a cohort of 21 adult CVID patients during a 17-year period at our center—according to the 2016 WHO classification and characterized the local and systemic immunological context

Results

The median time between the onset of CVID and lymphoma was 14 years. Patients showed a high prevalence of preceding immune dysregulation: lymphadenopathy (n = 13, 62%), splenomegaly (n = 18, 86%), autoimmune cytopenia (n = 14, 67%), and gastrointestinal involvement (n = 15, 71%). The entities comprised extranodal marginal zone lymphoma (n = 6), diffuse large B cell lymphoma (n = 7), plasmablastic lymphoma (n = 1), classic Hodgkin lymphoma (n = 4, including three cases with germline CTLA4 mutations), T cell large granular lymphocytic leukemia (n = 2), and peripheral T cell lymphoma, not otherwise specified (n = 1), but no follicular lymphoma. An Epstein-Barr virus association was documented in eight of 16 investigated lymphomas. High expression of PDL1 by tumor cells in five and of PDL1 and PD1 by tumor-infiltrating macrophages and T cells in 12 of 12 investigated lymphomas suggested a tolerogenic immunological tumor environment.

Conclusion

In summary, a diverse combination of specific factors like genetic background, chronic immune activation, viral trigger, and impaired immune surveillance contributes to the observed spectrum of lymphomas in CVID. In the future, targeted therapies, e.g., PD1/PDL1 inhibitors in CVID associated lymphomas with a tolerogenic environment may improve therapy outcome.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10875-021-01016-4.

Lymphopenia, Lymphopenia-Induced Proliferation, and Autoimmunity

Immune homeostasis is a tightly regulated system that is critical for defense against invasion by foreign pathogens and protection from self-reactivity for the survival of an individual. How the defects in this system might result in autoimmunity is discussed in this review. Reduced lymphocyte number, termed lymphopenia, can mediate lymphopenia-induced proliferation (LIP) to maintain peripheral lymphocyte numbers. LIP not only occurs in normal physiological conditions but also correlates with autoimmunity. Of note, lymphopenia is also a typical marker of immune aging, consistent with the fact that not only the autoimmunity increases in the elderly, but also autoimmune diseases (ADs) show characteristics of immune aging. Here, we discuss the types and rates of LIP in normal and autoimmune conditions, as well as the coronavirus disease 2019 in the context of LIP. Importantly, although the causative role of LIP has been demonstrated in the development of type 1 diabetes and rheumatoid arthritis, a two-hit model has suggested that the factors other than lymphopenia are required to mediate the loss of control over homeostasis to result in ADs. Interestingly, these factors may be, if not totally, related to the function/number of regulatory T cells which are key modulators to protect from self-reactivity. In this review, we summarize the important roles of lymphopenia/LIP and the Treg cells in various autoimmune conditions, thereby highlighting them as key therapeutic targets for autoimmunity treatments.

Inborn Errors of Immunity and Cancer

Simple Summary

Inborn Errors of Immunity (IEI) are a heterogeneous group of disorders characterized by a defect in the function of at least one, and often more, components of the immune system. The overall risk for cancer in children with IEI ranges from 4 to 25%. Several factors, namely, age of the patient, viral infection status and IEI type can influence the development of different cancer types. Immunologists and oncologists should interact to monitor and promptly diagnose the potential development of cancer in known IEI patients, as well as an underlying IEI in newly diagnosed cancers with suggestive medical history or high rate of therapy-related toxicity. The creation of an international registry of IEI cases with detailed information on the occurrence of cancer is fundamental to optimizing the diagnostic process and to evaluating the outcomes of new therapeutic options, with the aim of improving prognosis and reducing comorbidities.

Abstract

Inborn Errors of Immunity (IEI) are a heterogeneous group of disorders characterized by a defect in the function of at least one, and often more, components of the immune system. The aim of this narrative review is to discuss the epidemiology, the pathogenesis and the correct management of tumours in patients with IEI. PubMed was used to search for all of the studies published over the last 20 years using the keywords: “inborn errors of immunity” or “primary immunodeficiency” and “cancer” or “tumour” or “malignancy”. Literature analysis showed that the overall risk for cancer in children with IEI ranges from 4 to 25%. Several factors, namely, age of the patient, viral infection status and IEI type can influence the development of different cancer types. The knowledge of a specific tumour risk in the presence of IEI highlights the importance of a synergistic effort by immunologists and oncologists in tracking down the potential development of cancer in known IEI patients, as well as an underlying IEI in patients with newly diagnosed cancers. In the current genomic era, the creation of an international registry of IEI cases integrated with malignancies occurrence information is fundamental to optimizing the diagnostic process and to evaluating the outcomes of new therapeutic options, with the hope to obtain a better prognosis for these patients.

Heterogeneity in combined immunodeficiencies with associated or syndromic features (Review)

Primary immunodeficiencies are genetic diseases, mainly monogenic, that affect various components of the immune system and stages of the immune response. The category of combined immunodeficiencies with associated or syndromic features comprises over 70 clinical entities, characterized by heterogeneity of clinical presentation, mode of transmission, molecular, biological, mutational and immunological aspects. The mutational spectrum is wide, ranging from structural chromosomal abnormalities to gene mutations. The impact on the function of the proteins encoded by the genes involved is different; loss of function is most common, but situations with gain of function are also described. Most proteins have multiple functions and are components of several protein interaction networks. The pathophysiological mechanisms mainly involve: Missing enzymes, absent or non-functional proteins, abnormal DNA repair pathways, altered signal transduction, developmental arrest in immune differentiation, impairment of cell-to-cell and intracellular communications. Allelic heterogeneity, reduced penetrance and variable expressivity are genetic phenomena that cause diagnostic difficulties, especially since most are rare/very rare diseases, which is equivalent to delaying proper case management. Most primary immunodeficiencies are Mendelian diseases with X-linked or recessive inheritance, and molecular diagnosis allows the identification of family members at risk and the application of appropriate primary and secondary prevention measures in addition to the specific curative ones. In conclusion, recognizing heterogeneity and its sources is extremely important for current medical practice, but also for the theoretical value of improving biological and biomedical applications.

Higher Incidence of B Cell Malignancies in Primary Immunodeficiencies: A Combination of Intrinsic Genomic Instability and Exocytosis Defects at the Immunological Synapse

Congenital defects of the immune system called primary immunodeficiency disorders (PID) describe a group of diseases characterized by a decrease, an absence, or a malfunction of at least one part of the immune system. As a result, PID patients are more prone to develop life-threatening complications, including cancer. PID currently include over 400 different disorders, however, the variety of PID-related cancers is narrow. We discuss here reasons for this clinical phenotype. Namely, PID can lead to cell intrinsic failure to control cell transformation, failure to activate tumor surveillance by cytotoxic cells or both. As the most frequent tumors seen among PID patients stem from faulty lymphocyte development leading to leukemia and lymphoma, we focus on the extensive genomic alterations needed to create the vast diversity of B and T lymphocytes with potential to recognize any pathogen and why defects in these processes lead to malignancies in the immunodeficient environment of PID patients. In the second part of the review, we discuss PID affecting tumor surveillance and especially membrane trafficking defects caused by altered exocytosis and regulation of the actin cytoskeleton. As an impairment of these membrane trafficking pathways often results in dysfunctional effector immune cells, tumor cell immune evasion is elevated in PID. By considering new anti-cancer treatment concepts, such as transfer of genetically engineered immune cells, restoration of anti-tumor immunity in PID patients could be an approach to complement standard therapies.

The Italian Registry for Primary Immunodeficiencies (Italian Primary Immunodeficiency Network; IPINet): Twenty Years of Experience (1999-2019)

Primary immunodeficiencies (PIDs) are heterogeneous disorders, characterized by variable clinical and immunological features. National PID registries offer useful insights on the epidemiology, diagnosis, and natural history of these disorders. In 1999, the Italian network for primary immunodeficiencies (IPINet) was established. We report on data collected from the IPINet registry after 20 years of activity. A total of 3352 pediatric and adult patients affected with PIDs are registered in the database. In Italy, a regional distribution trend of PID diagnosis was observed. Based on the updated IUIS classification of 2019, PID distribution in Italy showed that predominantly antibody deficiencies account for the majority of cases (63%), followed by combined immunodeficiencies with associated or syndromic features (22.5%). The overall age at diagnosis was younger for male patients. The minimal prevalence of PIDs in Italy resulted in 5.1 per 100.000 habitants. Mortality was similar to other European registries (4.2%). Immunoglobulin replacement treatment was prescribed to less than one third of the patient cohort. Collectively, this is the first comprehensive description of the PID epidemiology in Italy.

Lymphoma Predisposing Gene in an Extended Family: CD70 Signaling Defect

Genome-wide sequencing studies in pediatric cancer cohorts indicate that about 10% of patients have germline mutations within cancer predisposition genes. Within this group, primary immune deficiencies take the priority regarding the vulnerability of the patients to infectious agents and the difficulties of cancer management. On the other hand, early recognition of these diseases may offer specific targeted therapies and hematopoietic stem cell transplantation as an option. Besides therapeutic benefits, early diagnosis will provide genetic counseling for the family members. Within this context, an extended family with multiple consanguineous marriages and affected individuals, who presented with combined immune deficiency (CID) and/or Hodgkin lymphoma phenotype, were examined by exome sequencing. A pathogenic homozygous missense CD70 variation was detected (NM_001252.5:c332C>T) in concordance with CD70 phenotype and familial segregation was confirmed. CD70 variations in patients with CID and malignancy have very rarely been reported. This paper reports extended family with multiple affected members with CID and malignancy carrying a missense CD70 variation, and reviews the rare cases reported in the literature. Primary immune deficiencies appear to be a potential cause for pediatric cancers. Better focusing on these inborn disorders to prevent or make an early diagnosis of malignant transformation and reduce mortalities is important.

The Possibilities of Immunotherapy for Children with Primary Immunodeficiencies Associated with Cancers

Many primary immunodeficiencies (PIDs) are recognised as being associated with malignancies, particularly lymphoid malignancies, which represent the highest proportion of cancers occurring in conjunction with this underlying condition. When patients present with genetic errors of immunity, clinicians must often reflect on whether to manage antitumoral treatment conventionally or to take a more personalised approach, considering possible existing comorbidities and the underlying status of immunodeficiency. Recent advances in antitumoral immunotherapies, such as monoclonal antibodies, antigen-specific adoptive cell therapies or compounds with targeted effects, potentially offer significant opportunities for optimising treatment for those patients, especially with lymphoid malignancies. In cases involving PIDs, variable oncogenic mechanisms exist, and opportunities for antitumoral immunotherapies can be considered accordingly. In cases involving a DNA repair defect or genetic instability, monoclonal antibodies can be proposed instead of chemotherapy to avoid severe toxicity. Malignancies secondary to uncontrolled virus-driven proliferation or the loss of antitumoral immunosurveillance may benefit from antivirus cell therapies or allogeneic stem cell transplantation in order to restore the immune antitumoral caretaker function. A subset of PIDs is caused by gene defects affecting targetable signalling pathways directly involved in the oncogenic process, such as the constitutive activation of phosphoinositol 3-kinase/protein kinase B (PI3K/AKT) in activated phosphoinositide 3-kinase delta syndrome (APDS), which can be settled with PI3K/AKT inhibitors. Therefore, immunotherapy provides clinicians with interesting antitumoral therapeutic weapons to treat malignancies when there is an underlying PID.

Malignancy post-hematopoietic stem cell transplant in patients with primary immunodeficiency

INTRODUCTION

Hematopoietic cell transplantation (HCT) is a curative treatment for an expanding number of primary immunodeficiencies (PIDs). Malignancies are more common in patients with PID than in the general population, and this review will discuss whether a successful HCT is expected to abolish or alter this risk. Second malignancy post HCT for a malignant disease is well known to occur, but generally less expected in patients transplanted for PID.

AREAS COVERED

This article reviews recently published literature focusing on the pattern of malignancy in children with PID, incidence, and risk factors for developing malignancy post-HCT for PID and possible strategies to reduce the risks.

EXPERT OPINION

Survival post HCT for PID has improved dramatically in the last 20 years and the genomic revolution has led to an expanding number of indications. To improve long-term quality of life attention needs to focus on late effects, including the possibility of malignancy occurring more frequently than expected in the general population, understand the risks and improve the process of transplantation in order to minimize them. Further studies are needed.

Primary immunodeficiencies and their associated risk of malignancies in children: an overview

Primary immunodeficiency disorders represent a heterogeneous spectrum of diseases, predisposing to recurrent infections, allergy, and autoimmunity. While an association between primary immunodeficiency disorders and increased risk of cancer has been suggested since the 1970s, renewed attention has been given to this topic in the last decade, largely in light of the availability of large registries as well as advances in next generation sequencing. In this narrative review, we will give an insight of the primary immunodeficiencies that are commonly responsible for the greater number of cancers in the primary immunodeficiency disorders population. We will describe clinical presentations, underlying genetic lesions (if known), molecular mechanisms for carcinogenesis, as well as some management considerations. We will also comment on the future directions and challenges related to this topic.Conclusion: The awareness of the association between several primary immunodeficiencies and cancer is crucial to provide the best care for these patients.What is Known: • Patients with primary immunodeficiency have an increased risk of malignancy. The type of malignancy is highly dependent on the specific primary immunodeficiency disorder.What is New: • Survival in patients with primary immunodeficiency disorders has been improving, and conversely also their lifetime risk of malignancy. • International collaboration and multinational registries are needed to improve our knowledge and therapeutic strategies.

Non-Hodgkin Lymphoma Epidemiology in Children From 2 Socioeconomic Regions in Mexico: 20-Year Registry (1996-2015)

PURPOSE

We analyzed the epidemiologic characteristics of different types of non-Hodgkin Lymphoma (NHL), excluding Burkitt Lymphoma, in 2 Mexican regions with different socioeconomic status.

MATERIALS AND METHODS

In this surveillance study, we analyzed the incidence rates (cases per million children/year) of different types of NHL according to the ICCC3, registered in 1996-2015, from 2 different socioeconomic regions in Mexico: central and southern, with higher and lower status, respectively.

RESULTS

The principal NHL subgroups were precursor (IIb1), mature B cell (IIb2), mature T/NK cell, and no other specification (NOS; 42.3%, 15.8%, 14.1%, and 27.8%, respectively). In both regions, the overall incidence rates were similar (central=5.3, 95% confidence interval [CI], 4.6-6.1 vs. southern=6.3, 95% CI, 4.6-8.4); also, there were no differences by types (precursor cell LNH, 2.3 vs. 2.5; mature B cell, 0.9 vs. 0.8; mature T/NK cells, 0.8 vs. 0.8; and NOS, 1.4 vs. 2.3). In both regions, a decreasing trend was found (central= -0.17%, 95% CI, -0.03 to -0.3, P=0.04; southern= -0.32%, 95% CI, -0.07 to -0.57, P=0.02), with major reduction of NHL NOS from 1996 to 2000. In both regions, men predominated (2.1:1).

CONCLUSIONS

Socioeconomic status did not influence the incidence rates of NHL. In this study, we found a reduction of NHL NOS, possibly due to better typing.

Serum Free Light Chains in Common Variable Immunodeficiency Disorders: Role in Differential Diagnosis and Association With Clinical Phenotype

We report on an observational, multicenter study of 345 adult CVID patients, designed to assess the diagnostic value and the clinical association of serum free light chain (sFLC) pattern in Common Variable Immunodeficiency disorders (CVID). Sixty CVID patients were tested twice in order to assess intraindividual variability of sFLC. As control groups we included 138 patients affected by undefined primary antibody defects (UAD), lymphoproliferative diseases (LPDs), and secondary antibody deficiencies not related to hematological malignancies (SID). CVID patients presented lower κ and λ chain concentration compared to controls, showing low intraindividual sFLC variability. On the basis of the sFLC pattern, patients were classified into four groups: κ-λ+, κ+λ-, κ-λ-, κ+λ+. The most common pattern in CVID patients was κ-λ- (51%), followed by κ-λ+, (25%), κ+λ+ (22%), and κ+λ- (3%). In UAD, LPD, and SID groups κ+λ+ was the most common pattern observed. By analyzing the possible association between sFLC patterns and disease-related complications of CVID, we observed that patients belonging to the κ-λ- group presented more commonly unexplained enteropathy compared to the κ+λ+ group and showed higher frequency of bronchiectasis and splenomegaly compared to both the κ-λ+ and κ+λ+ patients. When compared to the other groups, κ-λ- had also lower serum IgG, IgA, and IgM concentrations at diagnosis, lower frequency of CD27+IgD-IgM- switched memory B cells, and higher frequency of CD21^low B cells, receiving earlier CVID diagnosis. Thus, lower levels of sFLC might be an epiphenomenon of impairment in B cell differentiation, possibly leading κ-λ- patients to a higher risk for bacterial infections and chronic lung damage. Based on these results, we suggest adding sFLC assay to the diagnostic work-up of hypogammaglobulinemia and during follow-up. The assay may be useful to differentiate CVID from other causes of hypogammaglobulinemia and to early detect monoclonal lymphoproliferation occurring over years. Moreover, since the sFLC pattern seems to be related to disease phenotypes and clinical manifestations of CVID and after confirmation by further studies, sFLC assay might be considered a promising prognostic tool for identifying patients at higher risk of developing enteropathy and chronic lung damage or splenomegaly. This will allow designing a tailored follow-up for CVID patients.

Serum Free Light Chains in Common Variable Immunodeficiency Disorders: Role in Differential Diagnosis and Association With Clinical Phenotype

We report on an observational, multicenter study of 345 adult CVID patients, designed to assess the diagnostic value and the clinical association of serum free light chain (sFLC) pattern in Common Variable Immunodeficiency disorders (CVID). Sixty CVID patients were tested twice in order to assess intraindividual variability of sFLC. As control groups we included 138 patients affected by undefined primary antibody defects (UAD), lymphoproliferative diseases (LPDs), and secondary antibody deficiencies not related to hematological malignancies (SID). CVID patients presented lower κ and λ chain concentration compared to controls, showing low intraindividual sFLC variability. On the basis of the sFLC pattern, patients were classified into four groups: κ−λ+, κ+λ−, κ−λ−, κ+λ+. The most common pattern in CVID patients was κ−λ− (51%), followed by κ−λ+, (25%), κ+λ+ (22%), and κ+λ− (3%). In UAD, LPD, and SID groups κ+λ+ was the most common pattern observed. By analyzing the possible association between sFLC patterns and disease-related complications of CVID, we observed that patients belonging to the κ−λ− group presented more commonly unexplained enteropathy compared to the κ+λ+ group and showed higher frequency of bronchiectasis and splenomegaly compared to both the κ−λ+ and κ+λ+ patients. When compared to the other groups, κ−λ− had also lower serum IgG, IgA, and IgM concentrations at diagnosis, lower frequency of CD27+IgD–IgM– switched memory B cells, and higher frequency of CD21^low B cells, receiving earlier CVID diagnosis. Thus, lower levels of sFLC might be an epiphenomenon of impairment in B cell differentiation, possibly leading κ−λ− patients to a higher risk for bacterial infections and chronic lung damage. Based on these results, we suggest adding sFLC assay to the diagnostic work-up of hypogammaglobulinemia and during follow-up. The assay may be useful to differentiate CVID from other causes of hypogammaglobulinemia and to early detect monoclonal lymphoproliferation occurring over years. Moreover, since the sFLC pattern seems to be related to disease phenotypes and clinical manifestations of CVID and after confirmation by further studies, sFLC assay might be considered a promising prognostic tool for identifying patients at higher risk of developing enteropathy and chronic lung damage or splenomegaly. This will allow designing a tailored follow-up for CVID patients.

Heterogeneity of Liver Disease in Common Variable Immunodeficiency Disorders

Common variable immunodeficiency (CVID) is the most frequent primary immunodeficiency (PID) in adulthood and is characterized by severe reduction of immunoglobulin serum levels and impaired antibody production in response to vaccines and pathogens. Beyond the susceptibility to infections, CVID encompasses a wide spectrum of clinical manifestations related to a complex immune dysregulation that also affects liver. Although about 50% CVID patients present persistently deranged liver function, burden, and nature of liver involvement have not been systematically investigated in most cohort studies published in the last decades. Therefore, the prevalence of liver disease in CVID widely varies depending on the study design and the sampling criteria. This review seeks to summarize the evidence about the most relevant causes of liver involvement in CVID, including nodular regenerative hyperplasia (NRH), infections and malignancies. We also describe the clinical features of liver disease in some monogenic forms of PID included in the clinical spectrum of CVID as ICOS, NFKB1, NFKB2, CTLA-4, PI3Kδ pathway, ADA2, and IL21-R genetic defects. Finally, we discuss the clinical applications of the various diagnostic tools and the possible therapeutic approaches for the management of liver involvement in the context of CVID.

Cost and impact of early diagnosis in primary immunodeficiency disease: A literature review

BACKGROUND

New, innovative, costly diagnostic methods for patients with primary immunodeficiencies (PID) demand upfront insight into their potential cost savings and added value for individual patients. As such, high quality, comparable economic evaluations are of utmost importance to enable informed decisions. The objective of this review was therefore to create an extensive overview of current costing studies and potential cost savings of early diagnosis in primary immunodeficiency disease.

METHODS

A literature search in PubMed was conducted and studies involving any form of costing study in the field of PIDs were included. Of the included studies, study characteristics, cost parameters and benefits of early diagnosis were extracted and outlined in separate tables.

RESULTS

Twenty two studies met the inclusion criteria and were included in the review. The papers were categorized according to their subject: neonatal screening for severe combined immunodeficiency (SCID), Ig replacement therapies and studies reporting on costs of general or specific PIDs. Within and between these groups variability in reported costing characteristics was observed. In studies that reported cost savings pre- and post-diagnosis, cost savings ranged from 6500 to 108,463 USD of total costs per patient.

CONCLUSION

This literature review shows that, regardless of what aspect of PIDs has been studied, in nearly all cases early diagnosis reduces health care consumption and leads to better health outcomes for patients with PIDs. We found considerable variability in costing characteristics of economic evaluations of PID patients, which hampers the comparability of outcomes. More effort is needed to create uniformity and define cost parameters in economic evaluations in the field of PIDs, facilitating further prospective research to extensively assess the benefits of early diagnosis.

Malignancy and lymphoid proliferation in primary immune deficiencies; hard to define, hard to treat

BACKGROUND

Regarding the difficulties in recognition and management of the malignancies in primary immune deficiencies (PIDs), we aimed to present the types, risk factors, treatment options, and prognosis of the cancers in this specific group.

METHODS

Seventeen patients with PID who developed malignancies or malignant-like diseases were evaluated for demographics, clinical features, treatment, toxicity, and prognosis.

RESULTS

The median age of malignancy was 12.2 years (range, 2.2-26). Lymphoma was the most frequent malignancy (n = 7), followed by adenocarcinoma (n = 3), squamous cell carcinoma (n = 2), cholangiocarcinoma (n = 1), Wilms tumor (n = 1), and acute myeloid leukemia (n = 1). Nonneoplastic lymphoproliferation mimicking lymphoma was observed in five patients. The total overall survival (OS) was 62.5% ± 12.1%. The OS for lymphoma was 62.2% ± 17.1% and found to be inferior to non-PID patients with lymphoma (P = 0.001).

CONCLUSION

In patients with PIDs, malignancy may occur and negatively affect the OS. The diagnosis can be challenging in the presence of nonneoplastic lymphoproliferative disease or bone marrow abnormalities. Awareness of susceptibility to malignant transformation and early diagnosis with multidisciplinary approach can save the patients' lives.

The pitfalls and promise of liquid biopsies for diagnosing and treating solid tumors in children: a review

Cell-free DNA profiling using patient blood is emerging as a non-invasive complementary technique for cancer genomic characterization. Since these liquid biopsies will soon be integrated into clinical trial protocols for pediatric cancer treatment, clinicians should be informed about potential applications and advantages but also weaknesses and potential pitfalls. Small retrospective studies comparing genetic alterations detected in liquid biopsies with tumor biopsies for pediatric solid tumor types are encouraging. Molecular detection of tumor markers in cell-free DNA could be used for earlier therapy response monitoring and residual disease detection as well as enabling detection of pathognomonic and therapeutically relevant genomic alterations.Conclusion: Existing analyses of liquid biopsies from children with solid tumors increasingly suggest a potential relevance for molecular diagnostics, prognostic assessment, and therapeutic decision-making. Gaps remain in the types of tumors studied and value of detection methods applied. Here we review the current stand of liquid biopsy studies for pediatric solid tumors with a dedicated focus on cell-free DNA analysis. There is legitimate hope that integrating fully validated liquid biopsy-based innovations into the standard of care will advance patient monitoring and personalized treatment of children battling solid cancers.What is Known:• Liquid biopsies are finding their way into routine oncological screening, diagnosis, and disease monitoring in adult cancer types fast.• The most widely adopted source for liquid biopsies is blood although other easily accessible body fluids, such as saliva, pleural effusions, urine, or cerebrospinal fluid (CSF) can also serve as sources for liquid biopsiesWhat is New:• Retrospective proof-of-concept studies in small cohorts illustrate that liquid biopsies in pediatric solid tumors yield tremendous potential to be used in diagnostics, for therapy response monitoring and in residual disease detection.• Liquid biopsy diagnostics could tackle some long-standing issues in the pediatric oncology field; they can enable accurate genetic diagnostics in previously unbiopsied tumor types like renal tumors or brain stem tumors leading to better treatment strategies.

Novel Developments in Primary Immunodeficiencies (PID)-a Rheumatological Perspective

PURPOSE OF REVIEW

The purpose of this review is to provide an overview of the most relevant new disorders, disease entities, or disease phenotypes of primary immune deficiency disorders (PID) for the interested rheumatologist, using the new phenotypic classification by the IUIS (International Union of Immunological Societies) as practical guide.

RECENT FINDINGS

Newly recognized disorders of immune dysregulation with underlying mutations in genes pertaining to the function of regulatory T cells (e.g., CTLA-4, LRBA, or BACH2) are characterized by multiple autoimmune diseases-mostly autoimmune cytopenia-combined with an increased susceptibility to infections due to hypogammaglobulinemia. On the other hand, new mutations (e.g., in NF-kB1, PI3Kδ, PI3KR1, PKCδ) leading to the clinical picture of CVID (common variable immmune deficiency) have been shown to increasingly associate with autoimmune diseases. The mutual association of autoimmune diseases with PID warrants increased awareness of immunodeficiencies when diagnosing autoimmune diseases with a possible need to initiate appropriate genetic tests.

Lentiviral Vectors for the Treatment and Prevention of Cystic Fibrosis Lung Disease

Despite the continued development of cystic fibrosis transmembrane conductance regulator (CFTR) modulator drugs for the treatment of cystic fibrosis (CF), the need for mutation agnostic treatments remains. In a sub-group of CF individuals with mutations that may not respond to modulators, such as those with nonsense mutations, CFTR gene transfer to airway epithelia offers the potential for an effective treatment. Lentiviral vectors are well-suited for this purpose because they transduce nondividing cells, and provide long-term transgene expression. Studies in primary cultures of human CF airway epithelia and CF animal models demonstrate the long-term correction of CF phenotypes and low immunogenicity using lentiviral vectors. Further development of CF gene therapy requires the investigation of optimal CFTR expression in the airways. Lentiviral vectors with improved safety features have minimized insertional mutagenesis safety concerns raised in early clinical trials for severe combined immunodeficiency using γ-retroviral vectors. Recent clinical trials using improved lentiviral vectors support the feasibility and safety of lentiviral gene therapy for monogenetic diseases. While work remains to be done before CF gene therapy reaches the bedside, recent advances in lentiviral vector development reviewed here are encouraging and suggest it could be tested in clinical studies in the near future.

Skin disorders are prominent features in primary immunodeficiency diseases: A systematic overview of current data

Primary immunodeficiency diseases (PIDs) are characterized by an increased risk of infections, autoimmunity, autoinflammation, malignancy, and allergic disorders. Skin disorders are also common clinical features in PIDs and may be among the presenting manifestations. Recognition of specific PID-associated skin conditions in combination with other clinical features as described in the currently used warning signs could raise suspicion of an underlying PID. We aimed to provide a systematically obtained overview of skin disorders and their prevalence in PIDs. Secondary, the prevalence of Staphylococcus (S.) aureus-associated skin disorders and atopy was reviewed, as these are the most prominent skin features in PIDs. A systematic search was performed in EMBASE, MEDLINE, Web of Science, Cochrane, and Google Scholar (up to May 9, 2018). All original observational and experimental human studies that address the presence of skin disorders in PIDs were selected. We rated study quality using the Institute of Health Economics Quality Appraisal Checklist for Case Series Studies. Sixty-seven articles (5030 patients) were included. Study quality ranged from 18.2% to 88.5%. A broad spectrum of skin disorders was reported in 30 PIDs, mostly in single studies with a low number of included patients. An overview of associated PIDs per skin disorder was generated. Data on S. aureus-associated skin disorders and atopy in PIDs were limited. In conclusion, skin disorders are prominent features in PIDs. Through clustering of PIDs per skin disorder, we provide a support tool to use in clinical practice that should raise awareness of PIDs based on presenting skin manifestations.

Primary Immunodeficiency and Cancer Predisposition Revisited: Embedding Two Closely Related Concepts Into an Integrative Conceptual Framework

Common understanding suggests that the normal function of a "healthy" immune system safe-guards and protects against the development of malignancies, whereas a genetically impaired one might increase the likelihood of their manifestation. This view is primarily based on and apparently supported by an increased incidence of such diseases in patients with specific forms of immunodeficiencies that are caused by high penetrant gene defects. As I will review and discuss herein, such constellations merely represent the tip of an iceberg. The overall situation is by far more varied and complex, especially if one takes into account the growing difficulties to define what actually constitutes an immunodeficiency and what defines a cancer predisposition. The enormous advances in genome sequencing, in bioinformatic analyses and in the functional in vitro and in vivo assessment of novel findings together with the availability of large databases provide us with a wealth of information that steadily increases the number of sequence variants that concur with clinically more or less recognizable immunological problems and their consequences. Since many of the newly identified hard-core defects are exceedingly rare, their tumor predisposing effect is difficult to ascertain. The analyses of large data sets, on the other hand, continuously supply us with low penetrant variants that, at least in statistical terms, are clearly tumor predisposing, although their specific relevance for the respective carriers still needs to be carefully assessed on an individual basis. Finally, defects and variants that affect the same gene families and pathways in both a constitutional and somatic setting underscore the fact that immunodeficiencies and cancer predisposition can be viewed as two closely related errors of development. Depending on the particular genetic and/or environmental context as well as the respective stage of development, the same changes can have either a neutral, predisposing and, in some instances, even a protective effect. To understand the interaction between the immune system, be it "normal" or "deficient" and tumor predisposition and development on a systemic level, one therefore needs to focus on the structure and dynamic functional organization of the entire immune system rather than on its isolated individual components alone.

Pinpointing a potential role for CLEC12B in cancer predisposition through familial exome sequencing

Predisposition to cancer is only partly understood, and thus, the contribution of still undiscovered cancer predisposing variants necessitates further research. In search of such variants, we performed exome sequencing on the germline DNA of a family with two children affected by ganglioneuroma and neuroblastoma. Applying stringent selection criteria, we identified a potential deleterious, missense mutation in CLEC12B, coding for a lectin C-type receptor that is predicted to regulate immune function. Although further screening in a larger population and functional characterization is needed, we propose CLEC12B as a candidate cancer predisposition gene.

Primary Immunodeficiencies and Oncological Risk: The Experience of the Children's Hospital of Brescia

Background and aims: Primary immunodeficiencies (PID) are characterized by recurrent infections and increased risk of malignancies because of the reduced immunological surveillance against cancer cells and oncogenic viruses. Methods: We report the incidence of tumors among 690 patients with PID, diagnosed from 1990 until 2017 in Brescia. Results: Out of 690 patients, 25 patients (3.6%) developed 33 tumors. Of the 25 affected patients, 8 patients suffered from common variable immunodeficiency (CVID), 5 from combined immunodeficiency (CID), 3 from Ataxia-telangectasia (AT), 2 from Hermanksy-Pudlak type 2 (HSP2), 2 from gammaglobulinemia X-linked (XLA), 2 from Wiskott-Aldrich syndrome (WAS), 2 from Hyper IgE syndrome (HIES), 1 from severe combined immunodeficiency (SCID). The age at diagnosis ranged from 1 to 52 years, with a median age of 19.6 years. The time between the diagnosis of PID and onset of tumor was short, often <1 year between diagnosis and the appearance of cancer in the case of CID. Moreover, in two cases of CID, the diagnosis of cancer was made before the diagnosis of PID, so cancer was the onset clinical manifestation. Hematological malignancies were prevalent (22/33, 66.7%) with a minority of solid tumors (11/33, 33.33%). In particular Non-Hodgkin lymphomas were the most frequent (16/33, 48.48%). In total 13 patients survived (52%) and tumor was the main cause of death (7 cases). Two patients underwent BMT once the disease was in remission. Conclusions: Therefore, the correct management of tumors that arise in patients with primitive immunodeficiency still represents a challenge in the pediatric field. For this reason now it is mandatory to collect in a unique international registry the cases of malignancies in PID that could lead to a better understanding of the etiopathogenesis and of the biological and clinical characteristics of these tumors, with the aim of defining adequate preventive measures and guaranteeing an early diagnosis which also creating a shared and specific therapeutic strategy, with the prospect of obtaining a better prognosis for these patients.

Primary Immunodeficiency and Cancer in Children; A Review of the Literature

The life span of patients with primary and secondary immunodeficiencies has increased due to recent advances in diagnostic and therapeutic strategies. Primary immune deficiencies (PIDs) are genetic disorders that predispose patients to frequent infections, autoimmunity and malignancies. Genomic instability due to defective DNA repair processes and other unknown mechanisms in patients with PID leads to an enhanced risk of cancer. PIDs were originally described as rare diseases occurring only in infants and young children, which are associated with severe clinical symptoms. However, advances in gene sequencing technologies, have revealed that they are much more common than originally appreciated and are present in older children, adolescents, and adults. After infection, malignancy is the most prevalent cause of death in both children and adults with PIDs. The overall risk of developing cancer in patients with PID is estimated to range from 4.7 to 5.7 percent. A 1.4 to 1.6-fold excess relative risk of cancer has been reported for PIDs. Increasing awareness among physicians regarding PID and cancer may lead to earlier diagnosis which may decrease morbidity and mortality. In this paper, we review the various categories of PIDs in children and highlight their association with various malignancies. MEDLINE was searched to identify articles for inclusion. Three authors have independently screened literature search results from MEDLINE and abstracted data from studies dealing with cancers of children among primary immune deficiencies.

Current Understanding and Future Research Priorities in Malignancy Associated With Inborn Errors of Immunity and DNA Repair Disorders: The Perspective of an Interdisciplinary Working Group

Patients with inborn errors of immunity or DNA repair defects are at significant risk of developing malignancy and this complication of their underlying condition represents a substantial cause of morbidity and mortality. Whilst this risk is increasingly well-recognized, our understanding of the causative mechanisms remains incomplete. Diagnosing cancer is challenging in the presence of underlying co-morbidities and frequently other inflammatory and lymphoproliferative processes. We lack a structured approach to management despite recognizing the competing challenges of poor response to therapy and increased risk of toxicity. Finally, clinicians need guidance on how to screen for malignancy in many of these predisposing immunodeficiencies. In order to begin to address these challenges, we brought together representatives of European Immunology and Pediatric Haemato-Oncology to define the current state of our knowledge and identify priorities for clinical and research development. We propose key developmental priorities which our two communities will need to work together to address, collaborating with colleagues around the world.

The Iceberg Map of germline mutations in childhood cancer: focus on primary immunodeficiencies

PURPOSE OF REVIEW

The risk of cancer is higher, and its outcome is worse in patients with primary immunodeficiency (PID) than in members of the general population. Thus, the inter-relationship of malignant diseases with PIDs requires more study.

RECENT FINDINGS

Large genetic screens identified a vast number of germline mutations in childhood cancer patient samples. Although TP53 was the most frequent single gene identified as mutated, many PID disorders like DNA repair defects are among the inborn causes of childhood cancer. We provide a comprehensive analysis of compiled data from seven recent studies that focused on germline genetic landscapes and preexisting conditions in pediatric oncology. As potentially causal germline variants were identified in ≈8% of malignancies in children and adolescents, we visualized this proportion as the 'tips of the icebergs'. The results of additional network analyses showed the shared patterns of germline mutations in various malignancies and yielded a spatial distribution of the 'icebergs'.

SUMMARY

The 'iceberg map of germline mutations in childhood cancers' was created to increase the awareness of the inborn genetic underpinnings of childhood malignancies and their relationships with immunodeficiencies. Needs and perspectives of clinical immunologists and pediatric oncologists to both improve patient care and guide research at this critical interface are discussed. VIDEO ABSTRACT.

Genes at the Crossroad of Primary Immunodeficiencies and Cancer

Primary immunodeficiencies (PIDs) are a heterogeneous group of inherited disorders affecting one or multiple components of the innate and/or adaptive immune system. Currently, over 300 underlying genetic defects have been discovered. The most common clinical findings in patients with PIDs are infections, autoimmunity, and malignancies. Despite international efforts, the cancer risk associated with PIDs, given the heterogeneous character of this group of diseases, is difficult to estimate. The diverse underlying mechanisms of cancer in PID add another layer of complexity. Treatment of cancer within a context of PID is complicated by serious toxicities and long-term effects, including second malignancies. This review will focus on the little-known crossroad between PID and cancer genes and the value thereof for directing future research on our understanding of cancer in PID and for the identification of early cancer biomarkers in PID patients.

Mild Hypogammaglobulinemia Can Be a Serious Condition

Background: Most patients with primary antibody deficiency (PAD) suffer from less well-described and understood forms of hypogammaglobulinemia (unclassified primary antibody deficiency, unPAD). Because of the moderately decreased immunoglobulin levels compared to CVID, unPAD is generally considered to be clinically mild and not very relevant.

Objective: To describe our cohort of—mainly—unPAD patients, and to analyze whether subgroups can be identified.

Methods: Data were prospectively collected (February-2012 to June-2016) as part of a standardized, 1-day Care Pathway for suspected primary immunodeficiency. The TNO-AZL Questionnaire for Health-Related Quality of Life (HRQoL) was part of the pre-first-visit intake procedure.

Results: Three hundred and twenty patients were referred to the Care Pathway. Data from 23/27 children and 99/113 adults who were diagnosed with PAD and gave informed consent were available for analysis. 89/99 adults had unPAD, the majority (74%) were female and 44% already showed bronchiectasis. HRQoL was significantly decreased in all domains, meaning that a lot of unPAD patients had to cope simultaneously with pain, negative feelings and impairments in cognition, home management tasks, sleep, social interaction, and work. The most prominently impaired HRQoL domain was vitality, indicating these patients feel extremely tired and worn out.

Conclusion: These results highlight the need for more attention to the potential patient burden of unPADs. A larger cohort is needed to increase our understanding of unPADs and to analyze whether distinct subgroups can be identified. For now, it is important for the clinician to acknowledge the existence of unPAD and be aware of its potential consequences, in order to timely and appropriately manage its effects and complications.

A Tumor Profile in Primary Immune Deficiencies Challenges the Cancer Immune Surveillance Concept

Under the concept of cancer immune surveillance, individuals with primary immune deficiencies would be expected to develop many more malignancies and show an excess of all types of cancers, compared to people with a normal immune system. A review of the nine most frequent and best-documented human conditions with primary immune deficiency reveals a 1.6- to 2.3-fold global increase of cancer in the largest epidemiological studies. However, the spectrum of cancer types with higher frequencies is narrow, limited mainly to lymphoma, digestive tract cancers, and virus-induced cancers. Increased lymphoma is also reported in animal models of immune deficiency. Overstimulation of leukocytes, chronic inflammation, and viruses explain this tumor profile. This raises the question of cancers being foreign organisms or tissues. Organisms, such as bacteria, viruses, and parasites as well as non-compatible grafts are seen as foreign (non-self) and identified and destroyed or rejected by the body (self). As cancer cells rarely show strong (and unique) surface antibodies, their recognition and elimination by the immune system is theoretically questionable, challenging the immune surveillance concept. In the neonatal period, the immune system is weak, but spontaneous regression and good outcomes occur for some cancers, suggesting that non-immune factors are effective in controlling cancer. The idea of cancer as a group of cells that must be destroyed and eliminated appears instead as a legacy of methods and paradigms in microbiological medicine. As an alternative approach, cancer cells could be considered part of the body and could be controlled by an embryonic and neonatal environment.