Non-Hodgkin lymphoma (NHL) in children with Nijmegen Breakage syndrome (NBS)

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.

Genetic Predisposition to Hematologic Malignancies in Childhood and Adolescence

Advances in molecular biology and genetic testing have greatly improved our understanding of the genetic basis of hematologic malignancies and have enabled the identification of new cancer predisposition syndromes. Recognizing a germline mutation in a patient affected by a hematologic malignancy allows for a tailored treatment approach to minimize toxicities. It informs the donor selection, the timing, and the conditioning strategy for hematopoietic stem cell transplantation, as well as the comorbidities evaluation and surveillance strategies. This review provides an overview of germline mutations that predispose to hematologic malignancies, focusing on those most common during childhood and adolescence, based on the new International Consensus Classification of Myeloid and Lymphoid Neoplasms.

Consensus Recommendations for the Clinical Management of Hematological Malignancies in Patients with DNA Double Stranded Break Disorders

Patients with double stranded DNA repair disorders (DNARDs) (Ataxia Telangiectasia (AT) and Nijmegen Breakage syndrome (NBS)) are at a very high risk for developing hematological malignancies in the first two decades of life. The most common neoplasms are T-cell lymphoblastic malignancies (T-cell ALL and T-cell LBL) and diffuse large B cell lymphoma (DLBCL). Treatment of these patients is challenging due to severe complications of the repair disorder itself (e.g., congenital defects, progressive movement disorders, immunological disturbances and progressive lung disease) and excessive toxicity resulting from chemotherapeutic treatment. Frequent complications during treatment for malignancies are deterioration of pre-existing lung disease, neurological complications, severe mucositis, life threating infections and feeding difficulties leading to significant malnutrition. These complications make modifications to commonly used treatment protocols necessary in almost all patients. Considering the rarity of DNARDs it is difficult for individual physicians to obtain sufficient experience in treating these vulnerable patients. Therefore, a team of experts assembled all available knowledge and translated this information into best available evidence-based treatment recommendations.

Involvement of classic and alternative non-homologous end joining pathways in hematologic malignancies: targeting strategies for treatment

Chromosomal translocations are the main etiological factor of hematologic malignancies. These translocations are generally the consequence of aberrant DNA double-strand break (DSB) repair. DSBs arise either exogenously or endogenously in cells and are repaired by major pathways, including non-homologous end-joining (NHEJ), homologous recombination (HR), and other minor pathways such as alternative end-joining (A-EJ). Therefore, defective NHEJ, HR, or A-EJ pathways force hematopoietic cells toward tumorigenesis. As some components of these repair pathways are overactivated in various tumor entities, targeting these pathways in cancer cells can sensitize them, especially resistant clones, to radiation or chemotherapy agents. However, targeted therapy-based studies are currently underway in this area, and furtherly there are some biological pitfalls, clinical issues, and limitations related to these targeted therapies, which need to be considered. This review aimed to investigate the alteration of DNA repair elements of C-NHEJ and A-EJ in hematologic malignancies and evaluate the potential targeted therapies against these pathways.

Acute Lymphoblastic Leukemia and Acute Lymphoblastic Lymphoma: Same Disease Spectrum but Two Distinct Diagnoses

PURPOSE OF REVIEW

Rare malignancies developing from lymphocyte precursor cells, lymphoblastic leukemia (LBL), and acute lymphoblastic lymphoma (ALL) have historically been viewed as different manifestations of the same disease process. This review examines data on their epidemiology, genetics, clinical presentation, and response to treatment while highlighting areas of similarity and divergence between these two clinical entities.

RECENT FINDINGS

Pediatric-type ALL chemotherapy regimens, compared to both lymphoma-type chemotherapy and adult-type ALL regimens, have led to improved outcomes for children, adolescents, and young adults with ALL. BCR-ABL-targeting tyrosine kinase inhibitors (TKIs) have improved outcomes in Philadelphia chromosome-positive (Ph +) ALL and in rare cases of Ph + LBL. Newer therapies including blinatumomab, inotuzumab, CAR-T therapy, and nelarabine have improved outcomes in selected cases of ALL and have an emerging role in the management of LBL. Better understanding of ALL and LBL biology allows for the development of therapies that target immunophenotypic or genetic features found in subsets of both diseases. Novel therapies are leading to improved outcomes in Ph + and relapsed and refractory disease.

Considerations for radiotherapy in Bloom Syndrome: A case series

Bloom Syndrome (BS) is a genetic DNA repair disorder, caused by mutations in the BLM gene. The clinical phenotype includes growth retardation, immunodeficiency and a strong predisposition to different types of malignancies. Treatment of malignancies in BS patients with radiotherapy or chemotherapy is believed to be associated with increased toxicity, but clinical and laboratory data are lacking. We collected clinical data of two Dutch BS patients with solid tumors. Both were treated with radiotherapy before the diagnosis BS was made and tolerated this treatment well. In addition, we collected fibroblasts from BS patients to perform in vitro clonogenic survival assays to determine radiosensitivity. BS fibroblasts showed less radiosensitivity than the severely radiosensitive Artemis fibroblasts. Moreover, studies of double strand break kinetics by counting 53BP1 foci after irradiation showed similar patterns compared to healthy controls. In combination, the clinical cases and laboratory experiments are valuable information in the discussion whether radiotherapy is absolutely contraindicated in BS, which is the Case in other DNA repair syndromes like Ataxia Telangiectasia and Artemis.

Human Radiosensitivity and Radiosusceptibility: What Are the Differences?

The individual response to ionizing radiation (IR) raises a number of medical, scientific, and societal issues. While the term "radiosensitivity" was used by the pioneers at the beginning of the 20st century to describe only the radiation-induced adverse tissue reactions related to cell death, a confusion emerged in the literature from the 1930s, as "radiosensitivity" was indifferently used to describe the toxic, cancerous, or aging effect of IR. In parallel, the predisposition to radiation-induced adverse tissue reactions (radiosensitivity), notably observed after radiotherapy appears to be caused by different mechanisms than those linked to predisposition to radiation-induced cancer (radiosusceptibility). This review aims to document these differences in order to better estimate the different radiation-induced risks. It reveals that there are very few syndromes associated with the loss of biological functions involved directly in DNA damage recognition and repair as their role is absolutely necessary for cell viability. By contrast, some cytoplasmic proteins whose functions are independent of genome surveillance may also act as phosphorylation substrates of the ATM protein to regulate the molecular response to IR. The role of the ATM protein may help classify the genetic syndromes associated with radiosensitivity and/or radiosusceptibility.

Hematopoietic Stem Cell Transplantation Positively Affects the Natural History of Cancer in Nijmegen Breakage Syndrome

PURPOSE

Nijmegen breakage syndrome (NBS) is a DNA repair disorder with a high predisposition to hematologic malignancies.

EXPERIMENTAL DESIGN

We describe the natural history of NBS, including cancer incidence, risk of death, and the potential effectiveness of hematopoietic stem cell transplantation (HSCT) in preventing both pathologies: malignancy and immunodeficiency.

RESULTS

Among 241 patients with NBS enrolled in the study from 11 countries, 151 (63.0%) patients were diagnosed with cancer. Incidence rates for primary and secondary cancer, tumor characteristics, and risk factors affecting overall survival (OS) were estimated. The cumulative cancer incidence was 40.21% ± 3.5% and 77.78% ± 3.4% at 10 years and 20 years of follow-up, respectively. Most of the tumors n = 95 (62.9%) were non-Hodgkin lymphomas. Overall, 20 (13.2%) secondary malignancies occurred at a median age of 18 (interquartile range, 13.7-21.5) years. The probability of 20-year overall survival (OS) for the whole cohort was 44.6% ± 4.5%. Patients who developed cancer had a shorter 20-year OS than those without malignancy (29.6% vs. 86.2%; P < 10^-5). A total of 49 patients with NBS underwent HSCT, including 14 patients transplanted before malignancy. Patients with NBS with diagnosed cancer who received HSCT had higher 20-year OS than those who did not (42.7% vs. 30.3%; P = 0.038, respectively). In the group of patients who underwent preemptive transplantation, only 1 patient developed cancer, which is 6.7 times lower as compared with nontransplanted patients [incidence rate ratio 0.149 (95% confidence interval, 0.138-0.162); P < 0.0001].

CONCLUSIONS

There is a beneficial effect of HSCT on the long-term survival of patients with NBS transplanted in their first complete remission of cancer.

DNA Repair Syndromes and Cancer: Insights Into Genetics and Phenotype Patterns

DNA damage response is essential to human physiology. A broad spectrum of pathologies are displayed by individuals carrying monoallelic or biallelic loss-of-function mutations in DNA damage repair genes. DNA repair syndromes with biallelic disturbance of essential DNA damage response pathways manifest early in life with multi-systemic involvement and a high propensity for hematologic and solid cancers, as well as bone marrow failure. In this review, we describe classic biallelic DNA repair cancer syndromes arising from faulty single- and double-strand DNA break repair, as well as dysfunctional DNA helicases. These clinical entities include xeroderma pigmentosum, constitutional mismatch repair deficiency, ataxia telangiectasia, Nijmegen breakage syndrome, deficiencies of DNA ligase IV, NHEJ/Cernunnos, and ERCC6L2, as well as Bloom, Werner, and Rothmund-Thompson syndromes. To give an in-depth understanding of these disorders, we provide historical overview and discuss the interplay between complex biology and heterogeneous clinical manifestations.

Chromosomal instability associated with adverse outcome: a case report of patient with Nijmegen breakage syndrome and rapidly developed T-NHL with complex karyotype

BACKGROUND

Nijmegen breakage syndrome (NBS) is a rare genetic disorder inherited in an autosomal recessive pattern associated with an increased risk of developing lymphoproliferative disorders, mainly non-Hodgkin lymphoma (NHL) and acute lymphoblastic leukemia (ALL). NBS patients are 50 times more likely to develop malignancy than healthy controls. Moreover, in NBS, mortality rate from cancers, mainly lymphomas, is the highest among all diseases associated with excessive fragility of chromosomes.

CASE PRESENTATION

This work presents a patient previously diagnosed with Nijmegen breakage syndrome who rapidly developed T-NHL despite of constant medical supervision. Cytogenetic karyotype and microarray tests revealed complex aberrations, indicating enhanced chromosomal instability. Despite initial steroid therapy, the patient passed away due to multiorgan failure.

CONCLUSIONS

The lack of well-established diagnostic procedures in NBS patients make it difficult to determine any therapeutic target or predictive marker. Moreover, anticancer treatment is the biggest challenge in NBS patients due to therapy-related toxicity and immunodeficiency. Our case indicates the importance of identifying parameters useful in prognosis of disease outcome, as main risk factor affecting overall survival in NBS patients is an extremely high incidence of malignancy development.

T Lymphocytes in Patients With Nijmegen Breakage Syndrome Demonstrate Features of Exhaustion and Senescence in Flow Cytometric Evaluation of Maturation Pathway

Patients with Nijmegen Breakage Syndrome (NBS) suffer from recurrent infections due to humoral and cellular immune deficiency. Despite low number of T lymphocytes and their maturation defect, the clinical manifestations of cell-mediated deficiency are not as severe as in case of patients with other types of combined immune deficiencies and similar T cell lymphopenia. In this study, multicolor flow cytometry was used for evaluation of peripheral T lymphocyte maturation according to the currently known differentiation pathway, in 46 patients with genetically confirmed NBS and 46 sex and age-matched controls. Evaluation of differential expression of CD27, CD31, CD45RA, CD95, and CD197 revealed existence of cell subsets so far not described in NBS patients. Although recent thymic emigrants and naïve T lymphocyte cell populations were significantly lower, the generation of antigen-primed T cells was similar or even greater in NBS patients than in healthy controls. Moreover, the senescent and exhausted T cell populations defined by expression of CD57, KLRG1, and PD1 were more numerous than in healthy people. Although this hypothesis needs further investigations, such properties might be related to an increased susceptibility to malignancy and milder clinical course than expected in view of T cell lymphopenia in patients with NBS.

Diagnosis of Bloom Syndrome in a Patient with Short Stature, Recurrence of Malignant Lymphoma, and Consanguineous Origin

Bloom syndrome is an autosomal recessive disorder characterized by prenatal and postnatal growth deficiency, photosensitive skin changes, immune deficiency, insulin resistance, and a greatly increased risk of early-onset cancer and development of multiple malignancies. Loss-of-function variants of the BLM gene, which codes for a RecQ helicase, cause Bloom syndrome. We report a consanguineous family, with 2 siblings showing clinical signs of suspected chromosome breakage disorder. One of them developed recurrent malignant lymphoma during lifetime. We performed next-generation sequencing analysis, focusing on cancer predisposition syndromes. We identified a homozygous pathogenic nonsense variant c.1642C>T (p.Gln548*) in the BLM gene in the proband, associated with Bloom syndrome. Sanger sequencing validated the presence of a homozygous pathogenic variant in the proband and also in the brother with short stature. In this article, we will focus on the clinical presentation of the syndrome in this particular family as well as the characteristics of malignancies found in the proband.

Update on DNA-Double Strand Break Repair Defects in Combined Primary Immunodeficiency

PURPOSE OF REVIEW

The most serious DNA damage, DNA double strand breaks (DNA-dsb), leads to mutagenesis, carcinogenesis or apoptosis if left unrepaired. Non-homologous end joining (NHEJ) is the principle repair pathway employed by mammalian cells to repair DNA-dsb. Several proteins are involved in this pathway, defects in which can lead to human disease. This review updates on the most recent information available for the specific diseases associated with the pathway.

RECENT FINDINGS

A new member of the NHEJ pathway, PAXX, has been identified, although no human disease has been associated with it. The clinical phenotypes of Artemis, DNA ligase 4, Cernunnos-XLF and DNA-PKcs deficiency have been extended. The role of haematopoietic stem cell transplantation, following reduced intensity conditioning chemotherapy, for many of these diseases is being advanced. In the era of newborn screening, urgent genetic diagnosis is necessary to correctly target appropriate treatment for patients with DNA-dsb repair disorders.

Nijmegen breakage syndrome: case report and review of literature

Nijmegen Breakage Syndrome (NBS) is a rare autosomalrecessive DNA repair disorder characterized by genomic instability andincreased risk of haematopoietic malignancies observed in morethan 40% of the patients by the time they are 20 years old. The underlying gene, NBS1, is located on human chromosome 8q21 and codes for a protein product termed nibrin, Nbs1 or p95. Over 90% of patients are homozygous for a founder mutation: a deletion of five base pairs which leads to a frame shift and protein truncation. Nibrin (NBN) plays an important role in the DNA damage response (DDR) and DNA repair. DDR is a crucial signalling pathway in apoptosis and senescence. Cardinal symptoms of Nijmegen breakage syndrome are characteristic: microcephaly, present at birth and progressive with age, dysmorphic facial features, mild growth retardation, mild-to-moderate intellectual disability, and, in females, hypergonadotropic hypogonadism. Combined cellular and humoral immunodeficiency with recurrent sino-pulmonary infections, a strong predisposition to develop malignancies (predominantly of lymphoid origin) and radiosensitivity are other integral manifestations of the syndrome. The diagnosis of NBS is initially based on clinical manifestations and is confirmed by genetic analysis. Prenatal molecular genetic diagnosis is possible if disease-causing mutations in both alleles of the NBN gene are known. No specific therapy is available for NBS; however, hematopoietic stem cell transplantation may be one option for some patients. Prognosis is generally poor due to the extremely high rate of malignancies. We present here a case of Nijmegen breakage syndrome associated with Hodgkin lymphomas and Combined variable immunodeficiency.

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.

Primary Immunodeficiencies: Diseases of Children and Adults - A Review

Primary immunodeficiencies (PIDs) belong to a group of rare congenital diseases occurring all over the world that may be seen in both children and adults. In most cases, genetic predispositions are already known. As shown in this review, genetic abnormalities may be related to dysfunction of the immune system, which manifests itself as recurrent infections, increased risk of cancer, and autoimmune diseases. This article reviews the various forms of PIDs, including their characterization, management strategies, and complications. Novel aspects of the diagnostics and monitoring of PIDs are presented.

Chromosome instability syndromes

Fanconi anaemia (FA), ataxia telangiectasia (A-T), Nijmegen breakage syndrome (NBS) and Bloom syndrome (BS) are clinically distinct, chromosome instability (or breakage) disorders. Each disorder has its own pattern of chromosomal damage, with cells from these patients being hypersensitive to particular genotoxic drugs, indicating that the underlying defect in each case is likely to be different. In addition, each syndrome shows a predisposition to cancer. Study of the molecular and genetic basis of these disorders has revealed mechanisms of recognition and repair of DNA double-strand breaks, DNA interstrand crosslinks and DNA damage during DNA replication. Specialist clinics for each disorder have provided the concentration of expertise needed to tackle their characteristic clinical problems and improve outcomes. Although some treatments of the consequences of a disorder may be possible, for example, haematopoietic stem cell transplantation in FA and NBS, future early intervention to prevent complications of disease will depend on a greater understanding of the roles of the affected DNA repair pathways in development. An important realization has been the predisposition to cancer in carriers of some of these gene mutations.

A Systematic Review on Predisposition to Lymphoid (B and T cell) Neoplasias in Patients With Primary Immunodeficiencies and Immune Dysregulatory Disorders (Inborn Errors of Immunity)

Primary immunodeficiencies and immune dysregulatory disorders (PIDDs; now referred to as inborn errors in immunity) are rare disorders with a prevalence of 41. 4 or 50.5 per 100,000 persons (1). The incidence of malignancy in PIDD patents is the second-highest cause of death in children as well as adults, after infection, and is higher in certain PIDDs compared to others. We performed a systematic review of the literature to identify reports of B cell and T cell neoplasias in PIDDs and clustered them based on their classification in the IUIS schema. As would be expected, higher susceptibility to malignancies are typically reported in patients with Common Variable Immunodeficiency (CVID), combined immunodeficiencies affecting cellular immunity, in particular, DNA repair defects, or in the context of impaired immune regulatory control. There is not much evidence of increased risk for cancer in patients with innate immune defects, indicating that not all types of infection or genetic susceptibility predispose equally to cancer risk. Viral infections, in particular EBV, HHV and HPV, have been shown to increase susceptibility to developing cancer, but also patients with defects in immune regulation, such as Autoimmune Lymphoproliferative Syndrome (ALPS), activated p110delta syndrome (APDS type 1) and IL-10 receptor deficiency among others have a higher incidence of neoplastic disease, particularly lymphomas. In fact, lymphomas account for two-thirds of all malignancies reported in PIDD patients (2), with either a combined immunodeficiency or DNA repair defect predominating as the underlying immune defect in one registry, or antibody deficiencies in another (3). The vast majority of lymphomas reported in the context of PIDDs are B cell lymphomas, though T cell lymphomas have been reported in a few studies, and tend to largely be associated with chromosomal breakage disorders (4) or Cartilage Hair Hypoplasia (5). There appears to be a much higher prevalence of T cell lymphomas in patients with secondary immunodeficiencies (6), though this could reflect treatment bias. We reviewed the literature and summarized the reports of B and T cell lymphoma in PIDD patients to survey the current state of knowledge in this area.

Breast cancer genetics in young women: What do we know?

Breast cancer (BC) in young women, generally defined in oncology as women who are 40 years of age or younger, represents 2 out of 10 BC cases in developing countries. Several research studies, including genetic cancer panel tests, genome-wide association studies, expression analyses and polymorphisms reports, have found that young women with BC exhibit a higher genetic susceptibility and specific genomic signature compared to postmenopausal women with BC. Thus, international guidelines recommend genetic counseling for this age population. This review presents the current state of the art of genetics and genomics with regards to young women with BC.

Recommendations for Childhood Cancer Screening and Surveillance in DNA Repair Disorders

DNA repair syndromes are heterogeneous disorders caused by pathogenic variants in genes encoding proteins key in DNA replication and/or the cellular response to DNA damage. The majority of these syndromes are inherited in an autosomal-recessive manner, but autosomal-dominant and X-linked recessive disorders also exist. The clinical features of patients with DNA repair syndromes are highly varied and dependent on the underlying genetic cause. Notably, all patients have elevated risks of syndrome-associated cancers, and many of these cancers present in childhood. Although it is clear that the risk of cancer is increased, there are limited data defining the true incidence of cancer and almost no evidence-based approaches to cancer surveillance in patients with DNA repair disorders. This article is the product of the October 2016 AACR Childhood Cancer Predisposition Workshop, which brought together experts from around the world to discuss and develop cancer surveillance guidelines for children with cancer-prone disorders. Herein, we focus on the more common of the rare DNA repair disorders: ataxia telangiectasia, Bloom syndrome, Fanconi anemia, dyskeratosis congenita, Nijmegen breakage syndrome, Rothmund-Thomson syndrome, and Xeroderma pigmentosum. Dedicated syndrome registries and a combination of basic science and clinical research have led to important insights into the underlying biology of these disorders. Given the rarity of these disorders, it is recommended that centralized centers of excellence be involved directly or through consultation in caring for patients with heritable DNA repair syndromes. Clin Cancer Res; 23(11); e23-e31. ©2017 AACRSee all articles in the online-only CCR Pediatric Oncology Series.

Germline mutations predisposing to diffuse large B-cell lymphoma

Genetic studies of diffuse large B-cell lymphomas (DLBCLs) in humans have revealed numerous targets of somatic mutations and an increasing number of potentially relevant germline alterations. The latter often affect genes involved in DNA repair and/or immune function. In general, defects in these genes also predispose to other conditions. Knowledge of these mutations can lead to disease-preventing measures in the patient and relatives thereof. Conceivably, these germline mutations will be taken into account in future therapy of the lymphoma. In other hematological malignancies, mutations originally found as somatic aberrations have also been shown to confer predisposition to these diseases, when occurring in the germline. Further interrogations of the genome in DLBCL patients are therefore expected to reveal additional hereditary predisposition genes. Our review shows that germline mutations have already been described in over one-third of the genes that are somatically mutated in DLBCL. Whether such germline mutations predispose carriers to DLBCL is an open question. Symptoms of the inherited syndromes associated with these genes range from anatomical malformations to intellectual disability, immunodeficiencies and malignancies other than DLBCL. Inherited or de novo alterations in protein-coding and non-coding genes are envisioned to underlie this lymphoma.

Circulating T Cells of Patients with Nijmegen Breakage Syndrome Show Signs of Senescence

Purpose

The Nijmegen breakage syndrome (NBS) is an inherited genetic disorder characterized by a typical facial appearance, microcephaly, growth retardation, immunodeficiency, and a strong predisposition to malignancies, especially of lymphoid origin. NBS patients have a mutation in the NBN gene which involves the repair of DNA double-strand breaks (DSBs). Here we studied the peripheral T cell compartment of NBS patients with a focus on immunological senescence.

Methods

The absolute numbers and frequencies of the different T cell subsets were determined in NBS patients from young age till adulthood and compared to age-matched healthy individuals (HI). In addition, we determined the expression of senescent T cell markers and the signal joint T cell receptor excision circles (sjTRECs) content.

Results

Our results demonstrate that NBS patients have reduced T cell numbers. NBS patients showed lower numbers of αβ⁺ T cells, but normal γδ⁺ T cell numbers compared to HI. Concerning the αβ⁺ T cells, both CD4⁺ as well as CD8⁺ T cells were excessively reduced in numbers compared to aged-matched HI. In addition, NBS patients showed higher frequencies of the more differentiated T cells expressing the senescent cell marker CD57 and did not express co-stimulatory molecule CD28. These effects were already present in the youngest age group. Furthermore, NBS patients showed lower sjTREC content in their T cells possibly indicative of a lower thymic output.

Conclusions

We conclude that circulating T cells from NBS patients show signs of a senescent phenotype which is already present from young age on and which might explain their T cell immune deficiency.

Electronic supplementary material

The online version of this article (doi:10.1007/s10875-016-0363-5) contains supplementary material, which is available to authorized users.

Cancers Related to Immunodeficiencies: Update and Perspectives

The life span of patients with primary and secondary immunodeficiency is increasing due to recent improvements in therapeutic strategies. While the incidence of primary immunodeficiencies (PIDs) is 1:10,000 births, that of secondary immunodeficiencies are more common and are associated with posttransplantation immune dysfunction, with immunosuppressive medication for human immunodeficiency virus or with human T-cell lymphotropic virus infection. After infection, malignancy is the most prevalent cause of death in both children and adults with (PIDs). PIDs more often associated with cancer include common variable immunodeficiency (CVID), Wiskott-Aldrich syndrome, ataxia-telangiectasia, and severe combined immunodeficiency. This suggests that a protective immune response against both infectious non-self-(pathogens) and malignant self-challenges (cancer) exists. The increased incidence of cancer has been attributed to defective elimination of altered or "transformed" cells and/or defective immunity towards cancer cells. The concept of aberrant immune surveillance occurring in PIDs is supported by evidence in mice and from patients undergoing immunosuppression after transplantation. Here, we discuss the importance of PID defects in the development of malignancies and the current limitations associated with molecular pathogenesis of these diseases and emphasize the need for further knowledge of how specific mutations can modulate the immune system to alter immunosurveillance and thereby play a key role in the etiology of malignancies in PID patients.

Non-Hodgkin lymphoma and pre-existing conditions: spectrum, clinical characteristics and outcome in 213 children and adolescents

Children and adolescents with pre-existing conditions such as DNA repair defects or other primary immunodeficiencies have an increased risk of non-Hodgkin lymphoma. However, large-scale data on patients with non-Hodgkin lymphoma and their entire spectrum of pre-existing conditions are scarce. A retrospective multinational study was conducted by means of questionnaires sent out to the national study groups or centers, by the two largest consortia in childhood non-Hodgkin lymphoma, the European Intergroup for Childhood non-Hodgkin Lymphoma, and the international Berlin-Frankfurt-Münster Study Group. The study identified 213 patients with non-Hodgkin lymphoma and a pre-existing condition. Four subcategories were established: a) cancer predisposition syndromes (n=124, 58%); b) primary immunodeficiencies not further specified (n=27, 13%); c) genetic diseases with no increased cancer risk (n=40, 19%); and d) non-classifiable conditions (n=22, 10%). Seventy-nine of 124 (64%) cancer predispositions were reported in groups with more than 20 patients: ataxia telangiectasia (n=32), Nijmegen breakage syndrome (n=26), constitutional mismatch repair deficiency (n=21). For the 151 patients with a known cancer risk, 5-year event-free survival and overall survival rates were 40%±4% and 51%±4%, respectively. Five-year cumulative incidences of progression/relapse and treatment-related death as a first event were 22%±4% and 24%±4%, respectively. Ten-year incidence of second malignancy was 24%±5% and 7-year overall survival of the 21 patients with a second malignancy was 41%±11%. Patients with non-Hodgkin lymphoma and pre-existing conditions have an inferior survival rate with a large proportion of therapy-related deaths compared to patients with non-Hodgkin lymphoma and no pre-existing conditions. They may require special vigilance when receiving standard or modified/reduced-intensity chemotherapy or when undergoing allogeneic stem cell transplantation.

T-lymphoblastic leukemia/lymphoma in macedonian patients with Nijmegen breakage syndrome

Nijmegen breakage syndrome (NBS) is a rare autosomal recessive chromosomal instability disorder characterized by microcephaly, immunodeficiency, radiosensitivity and a very high predisposition to malignancy. The gene responsible for the disease, NBS1, is located on chromosome 8q21 and encodes a protein called nibrin. After identification of the gene, a truncating 5 bp deletion, 657-661delACAAA, was identified as the disease-causing mutation in patients with the NBS. In this report, we describe two patients with NBS and T-lymphoblastic leukemia/lymphoma in a Macedonian family. To the best of our knowledge, this is the first family with NBS reported from Macedonia. Both children presented with microcephaly, syndactyly and the development of T cell lymphoblastic lekemia/lymphoma at the age of 7 and 10 years, respectively. The molecular analysis of NBS1 genes in our patients showed homozygosity for the 657del5 mutation in the NBS1 gene. The parents were heterozygotes for the 657del5 mutation and they had no knowledge of a consanguineous relationship. The first child was treated with the International Berlin-Frankfurt-Münster (BFM)-Non Hodgkin lymphoma (NHL) protocol and achieved a complete remission that lasted for 21 months. Subsequently, he developed a medullar relapse with hyperleukocytosis and died due to lethal central nervous system (CNS) complications. The second child was treated according to the International Collaborative Treatment Protocol for Children and Adolescents with Acute Lymphoblastic Leukemia 2009 (AIOP-BFM ALL 2009) protocol. Unfortunately, remission was not achieved.

Phenotypes and genotypes of the chromosomal instability syndromes

As defined initially, chromosome instability syndromes (CIS) are a group of inherited conditions transmitted in autosomal recessive pattern characterised with both mental and physical development delay generally. They are also with other medical complications in individuals with CIS commonly including different degree of dysmorphics, organs/systems dys-function and high risk of cancer predisposition. Chromosomal breakage from CIS can be seen either in spontaneous breakage around 10-15% observed in Fanconi anemia or induced by clastogenic agents such as mitomycin (MMC), diepoxybutane (DEB). The spontaneous chromosome breakage is less common but it correlates with patient clinical severity. Relative high rates of some types of CIS can occur in certain ethnic groups. Individuals with CIS are commonly in childhood and these disorders are often lethal. Diagnosis is complicated usually because the symptoms presented from individuals with CIS may be varied and complex. Advances in molecular level have identified genes responsible for such group diseases/disorders demonstrated that CIS are characterized by the genome instability, defect in DNA repair mechanisms. Latest advances in high-throughput technologies have been increasing sequencing capabilities to facilitate more accurate data for such syndrome researches. CIS are the typical rare diseases and becoming more challenges in pediatrics clinic. In the last two decades, there were no many articles to review and analysis CIS together to comparing their phenotypes and genotypes. In this article, the similarity and differences of the phenotypes and genotypes of CIS were reviewed to understanding the whole profiles of CIS to assist laboratory genetic diagnostic services in CIS and for the confirmation from the clinical referrals.

Clinical course and therapeutic implications for lymphoid malignancies in Nijmegen breakage syndrome

Nijmegen breakage syndrome (NBS, MIM #251260) is an autosomal recessive chromosomal instability disorder. Majority of patients affected are of Slavic origin and share the same founder mutation of 657del5 within the NBN gene encoding protein involved in DNA double-strand breaks repair. Clinically, this is characterized by a microcephaly, immunodeficiency and a high incidence of pediatric malignancies, mostly lymphomas and leukemias. Anticancer treatment among patients with NBS is challenging because of a high risk of life threatening therapy-related toxicity including severe infections, bone marrow failure, cardio- and nephrotoxicity and occurrence of secondary cancer. Based on systemic review of available literature and the Polish acute lymphoblastic leukemia database we concluded that among patients with NBS, these who suffered from clinically proven severe immunodeficiency are at risk of the complications associated with oncological treatment. Thus, in this group it reasonable to reduce chemotherapy up to 50% especially concerning anthracyclines methotrexate, alkylating agents and epipodophyllotoxines, bleomycin and radiotherapy should be omitted. Moreover, infection prophylaxis using intravenous immunoglobulin supplementation together with antifungal and antibacterial agent is recommended. To replace radiotherapy or some toxic anticancer agents targeted therapy using monoclonal antibodies and kinase inhibitors or bone marrow transplantation with reduced-intensity conditioning should be considered in some cases, however, this statement needs further studies.

Directed Alternative Splicing in Nijmegen Breakage Syndrome: Proof of Principle Concerning Its Therapeutical Application

Over 90% of patients with Nijmegen breakage syndrome (NBS), a hereditary cancer disorder, are homoallelic for a 5 bp deletion in the NBN gene involved in the cellular response to DNA damage. This hypomorphic mutation leads to a carboxy-terminal protein fragment, p70-nibrin, with some residual function. Average age at malignancy, typically lymphoma, is 9.7 years. NBS patients are hypersensitive to chemotherapeutic and radiotherapeutic treatments, thus prevention of cancer development is of particular importance. Expression of an internally deleted NBN protein, p80-nibrin, has been previously shown to be associated with a milder cellular phenotype and absence of cancer in a 62-year-old NBS patient. Here we show that cells from this patient, unlike other NBS patients, have DNA replication and origin firing rates comparable to control cells. We used here antisense oligonucleotides to enforce alternative splicing in NBS patient cells and efficiently generate the same internally deleted p80-nibrin protein. Injecting the same antisense sequences as morpholino oligomers (VivoMorpholinos) into the tail vein of a humanized NBS murine mouse model also led to efficient alternative splicing in vivo. Thus, proof of principle for the use of antisense oligonucleotides as a potential cancer prophylaxis has been demonstrated.

Secondary acute monocytic leukemia positive for 11q23 rearrangement in Nijmegen breakage syndrome

Nijmegen breakage syndrome (NBS) is an autosomal recessive chromosomal instability disorder characterized by a high incidence of pediatric hematologic malignancies. Majority of patients affected are of Slavic origin and share the same founder mutation of 657del5 within the NBN gene encoding protein involved in DNA double-strand breaks (DSB) repair. We report a case of a pediatric patient with NBS, who developed t(9;11)/AF9-MLL-positive AML as a second malignancy after successful treatment of T-NHL. The coexistence of NBN and MLL mutations suggests that the profound dysfunction of NBN may promote alterations of MLL that is mediated by error-prone non-homologous end joining pathway particularly in patients treated with DNA topoisomerase II inhibitors.

SCID patients with ARTEMIS vs RAG deficiencies following HCT: increased risk of late toxicity in ARTEMIS-deficient SCID

A subgroup of severe combined immunodeficiencies (SCID) is characterized by lack of T and B cells and is caused by defects in genes required for T- and B-cell receptor gene rearrangement. Several of these genes are also involved in nonhomologous end joining of DNA double-strand break repair, the largest subgroup consisting of patients with T(-)B(-)NK(+)SCID due to DCLRE1C/ARTEMIS defects. We postulated that in patients with ARTEMIS deficiency, early and late complications following hematopoietic cell transplantation might be more prominent compared with patients with T(-)B(-)NK(+)SCID caused by recombination activating gene 1/2 (RAG1/2) deficiencies. We analyzed 69 patients with ARTEMIS and 76 patients with RAG1/2 deficiencies who received transplants from either HLA-identical donors without conditioning or from HLA-nonidentical donors without or with conditioning. There was no difference in survival or in the incidence or severity of acute graft-versus-host disease regardless of exposure to alkylating agents. Secondary malignancies were not observed. Immune reconstitution was comparable in both groups, however, ARTEMIS-deficient patients had a significantly higher occurrence of infections in long-term follow-up. There is a highly significant association between poor growth in ARTEMIS deficiency and use of alkylating agents. Furthermore, abnormalities in dental development and endocrine late effects were associated with alkylation therapy in ARTEMIS deficiency.

Atypical strain of Toxoplasma gondii causing fatal reactivation after hematopoietic stem cell transplantion in a patient with an underlying immunological deficiency

In immunocompromized patients, including hematopoietic stem cell transplant (HSCT) recipients, life-threatening toxoplasmosis may result from reactivation of previous infection. We report a case of severe disseminated toxoplasmosis that developed early after allogeneic HSCT for T-cell lymphoblastic leukemia/lymphoma in a 15-year-old Toxoplasma gondii-seropositive boy with Nijmegen breakage syndrome, a rare genetic DNA repair disorder associated with immunodeficiency. The donor was the patient's HLA-identical brother. Prophylaxis with cotrimoxazole was discontinued a day before the HSCT procedure. Signs of lung infection appeared as early as day 14 post-HSCT. The presence of tachyzoite-like structures on Giemsa-stained bronchoalveolar lavage (BAL) fluid smears suggested toxoplasmosis. Real-time PCR targeted at the T. gondii AF146527 gene revealed extremely high parasite burdens in both blood and BAL fluid. Although immediate introduction of specific treatment resulted in a marked reduction of the parasite load and transient clinical improvement, the patient deteriorated and died of multiple organ failure on day 39 post-HSCT. Direct genotyping of T. gondii DNA from blood and BAL fluid with the PCR-restriction fragment length polymorphism method revealed type II alleles with SAG1, SAG2, and GRA6 markers but alleles of both type I and type II with GRA7. Additional analysis with 15 microsatellite markers showed that the T. gondii DNA was atypical and genetically divergent from that of the clonal type I, II, and III strains. This is the first report of increased clinical severity of toxoplasmosis associated with an atypical strain in the setting of immunosuppression, which emphasizes the need to diagnose and monitor toxoplasmosis by quantitative molecular methods in cases of reactivation risk.

DNA repair: the link between primary immunodeficiency and cancer

The adaptive component of the immune system depends greatly on the generation of genetic diversity provided by lymphocyte-specific genomic rearrangements. V(D)J recombination, class switch recombination (CSR), and somatic hypermutation (SHM) constitute complex and vulnerable processes that are orchestrated by a multitude of DNA repair pathways. When inherited defects in certain DNA repair proteins are present, lymphocyte development can be compromised and, consequently, patients can develop primary immunodeficiencies (PIDs). PID patients often have a strong predisposition for cancer development as a result of genomic instability generated from defective DNA repair mechanisms. Tumors of lymphoid origin are one of the most common PID-associated cancers, likely due to DNA lesions resulting from defective V(D)J, CSR, and SHM. In this review, we describe PID syndromes that confer an increased risk for cancer development. Furthermore, we discuss the role of the affected proteins in tumorigenesis/lymphomagenesis.

Nijmegen breakage syndrome (NBS)

Nijmegen breakage syndrome (NBS) is a rare autosomal recessive syndrome of chromosomal instability mainly characterized by microcephaly at birth, combined immunodeficiency and predisposition to malignancies. Due to a founder mutation in the underlying NBN gene (c.657_661del5) the disease is encountered most frequently among Slavic populations. The principal clinical manifestations of the syndrome are: microcephaly, present at birth and progressive with age, dysmorphic facial features, mild growth retardation, mild-to-moderate intellectual disability, and, in females, hypergonadotropic hypogonadism. Combined cellular and humoral immunodeficiency with recurrent sinopulmonary infections, a strong predisposition to develop malignancies (predominantly of lymphoid origin) and radiosensitivity are other integral manifestations of the syndrome. The NBN gene codes for nibrin which, as part of a DNA repair complex, plays a critical nuclear role wherever double-stranded DNA ends occur, either physiologically or as a result of mutagenic exposure. Laboratory findings include: (1) spontaneous chromosomal breakage in peripheral T lymphocytes with rearrangements preferentially involving chromosomes 7 and 14, (2) sensitivity to ionizing radiation or radiomimetics as demonstrated in vitro by cytogenetic methods or by colony survival assay, (3) radioresistant DNA synthesis, (4) biallelic hypomorphic mutations in the NBN gene, and (5) absence of full-length nibrin protein. Microcephaly and immunodeficiency are common to DNA ligase IV deficiency (LIG4 syndrome) and severe combined immunodeficiency with microcephaly, growth retardation, and sensitivity to ionizing radiation due to NHEJ1 deficiency (NHEJ1 syndrome). In fact, NBS was most commonly confused with Fanconi anaemia and LIG4 syndrome. Genetic counselling should inform parents of an affected child of the 25% risk for further children to be affected. Prenatal molecular genetic diagnosis is possible if disease-causing mutations in both alleles of the NBN gene are known. No specific therapy is available for NBS, however, hematopoietic stem cell transplantation may be one option for some patients. Prognosis is generally poor due to the extremely high rate of malignancies.

Zespół Nijmegen (Nijmegen breakage syndrome; NBS) jest rzadkim schorzeniem z wrodzoną niestabilnością chromosomową dziedziczącym się w sposób autosomalny recesywny, charakteryzującym się przede wszystkim wrodzonym małogłowiem, złożonymi niedoborami odporności i predyspozycją do rozwoju nowotworów.

Choroba występuje najczęściej w populacjach słowiańskich, w których uwarunkowana jest mutacją założycielską w genie NBN (c.657_661del5). Do najważniejszych objawów zespołu zalicza się: małogłowie obecne od urodzenia i postępujące z wiekiem, charakterystyczne cechy dysmorfii twarzy, opóźnienie wzrastania, niepełnosprawność intelektualną w stopniu lekkim do umiarkowanego oraz hipogonadyzm hipogonadotropowy u dziewcząt. Na obraz choroby składają się także: niedobór odporności komórkowej i humoralnej, który jest przyczyną nawracających infekcji, znaczna predyspozycja do rozwoju nowotworów złośliwych (zwłaszcza układu chłonnego), a także zwiększona wrażliwość na promieniowanie jonizujące. Wyniki badań laboratoryjnych wykazują: (1) spontaniczną łamliwość chromosomów w limfocytach T krwi obwodowej, z preferencją do rearanżacji chromosomów 7 i 14, (2) nadwrażliwość na promieniowanie jonizujące lub radiomimetyki, co można wykazać metodami in vitro, (3) radiooporność syntezy DNA, (4) hipomorficzne mutacje na obu allelach genu NBN, oraz (5) brak w komórkach pełnej cząsteczki białka, nibryny. Małogłowie i niedobór odporności występują także w zespole niedoboru ligazy IV (LIG4) oraz w zespole niedoboru NHEJ1. Rodzice powinni otrzymać poradę genetyczną ze względu na wysokie ryzyko (25%) powtórzenia się choroby u kolejnego potomstwa. Możliwe jest zaproponowanie molekularnej diagnostyki prenatalnej jeżeli znane są obie mutacje będące przyczyną choroby. Nie ma możliwości zaproponowania specyficznej terapii, ale przeszczep szpiku może być alternatywą dla niektórych pacjentów. Generalnie prognoza nie jest pomyślna z uwagi na wysokie ryzyko rozwoju nowotworu.

Nijmegen breakage syndrome (NBS) as a risk factor for CNS involvement in childhood acute lymphoblastic leukemia

Central nervous system (CNS) involvement is an independent risk factor for poor event-free survival and relapse confined to the CNS. Knock-out mice deprived of RAG2, the protein involved in DNA repair, developed leukemic infiltration within leptomeninges. Therefore, we hypothesized that DNA repair deficiencies in humans, such as Nijmegen breakage syndrome (NBS), may constitute a risk factor for CNS dissemination of acute lymphoblastic leukemia (ALL). Having analyzed the incidence of CNS2/CNS3 status at diagnosis of ALL in two independent cohorts from the Polish Pediatric Leukemia/Lymphoma Study Group, we noticed that among children with NBS CNS involvement was significantly frequent.

Malignancies in the setting of primary immunodeficiency: Implications for hematologists/oncologists

Many primary immunodeficiency disorders (PIDD) are associated with elevated risks for different types of cancer. Defective immunosurveillance mechanisms in PIDD and infection with oncogenic viruses (eg, Epstein Barr, herpesvirus 8) seem to have significant contributory roles in many cases. Non-Hodgkin lymphoma and Hodgkin disease are two of the most common PIDD-associated malignancies. The impact of PIDD-associated malignancy has increased in recent years in parallel with improved patient with PIDD survival and longevity, due largely to effective immunoglobulin replacement therapy. Epidemiologic data, clinical patterns, and management considerations of the common PIDD-associated cancers are reviewed.

High prevalence of the NBN gene mutation c.657-661del5 in Southeast Germany

Nijmegen breakage syndrome (NBS), a rare autosomal recessive chromosomal instability disorder, is caused by mutations in the NBN gene. Most patients known so far are of Slavic origin and carry the major founder mutation c.657-661del5. Due to an unexpectedly high incidence of NBS patients (homozygous for the c.657-661del5 mutation) in a Northeast Bavarian region in Southeast Germany, we estimated the prevalence of this mutation in this area and compared it to another German region. We found a high carrier frequency of 1/176 for the c.657-661del5 mutation among newborns in Northeast Bavaria, while the frequency of the mutation in Berlin was 1/990. We further studied families from a Slavic population isolate, the Sorbs, in the Lusatian region in Northeast Saxony, and revealed a prevalence of the c.657-661del5 mutation of 1/34. Whereas the Slavic origin of the Sorbs has been known, we attribute the surprisingly high frequencies of c.657-661del5 mutation in Bavaria (similar to frequencies of this mutation in various Eastern European countries) to a high percentage of people of Slavic origin in Northeast Bavaria.

Primary immunodeficiencies associated with DNA-repair disorders

DNA-repair pathways recognise and repair DNA damaged by exogenous and endogenous agents to maintain genomic integrity. Defects in these pathways lead to replication errors, loss or rearrangement of genomic material and eventually cell death or carcinogenesis. The creation of diverse lymphocyte receptors to identify potential pathogens requires breaking and randomly resorting gene segments encoding antigen receptors. Subsequent repair of the gene segments utilises ubiquitous DNA-repair proteins. Individuals with defective repair pathways are found to be immunodeficient and many are radiosensitive. The role of repair proteins in the development of adaptive immunity by VDJ recombination, antibody isotype class switching and affinity maturation by somatic hypermutation has become clearer over the past few years, partly because of identification of the genes involved in human disease. We describe the mechanisms involved in the development of adaptive immunity relating to DNA repair, and the clinical consequences and treatment of the primary immunodeficiency resulting from such defects.

Nijmegen breakage syndrome: Long-term monitoring of viral and immunological biomarkers in peripheral blood before development of malignancy

Selected viruses and immune parameters were monitored in 57 patients with Nijmegen breakage syndrome as a proposed tool for early detection of changes preceding development of malignancy. The following parameters were analysed: (1) viral infections; (2) monoclonal proteins; and (3) B-cell and T-cell receptor gene rearrangements in peripheral blood lymphocytes. Viral infections were detected in 68.4% of patients with a predominance of EBV (63.2%), followed by HBV (19.2%) and HCV (8.8%). Monoclonal gammopathy detected in 38.6% of cases correlated with the presence of EBV DNA (p=0.002) and HCV RNA (p=0.04). Clonal Ig and/or TCR gene rearrangements occurred in 73.9% of patients. The presence of at least one of the studied parameters preceded the development of malignancy in 22 patients. Systematic PCR analysis for viral infections and Ig/TCR gene rearrangements, supplemented by detection of monoclonal proteins, is advantageous in monitoring NBS patients before severe complications of the disease, including cancer, appear.

Successful SCT for Nijmegen breakage syndrome

Nijmegen breakage syndrome (NBS) is characterized by chromosomal instability, radiation hypersensitivity, characteristic facial appearance, immunodeficiency and strong predisposition to lymphoid malignancy. Traditionally, NBS patients have not undergone hematopoietic SCT (HSCT) owing to concerns about increased toxicity. We therefore report on the HSCT experience in NBS patients in Europe. Six patients were transplanted either for resistant or secondary malignancy (four patients) or severe immunodeficiency (two patients). Five patients received reduced-intensity conditioning regimens. After a median follow-up of 2.2 years, five patients are alive and well. One patient who received myeloablative conditioning died from sepsis before engraftment. Acute GVHD grades I-II occurred in three of five patients, mild chronic GVHD in one. All five surviving patients exhibit restored T-cell immunity. The experience in these six patients suggests that HSCT in NBS is feasible, can correct the immunodeficiency and effectively treat malignancy. Acute toxicity seems to be reasonable with reduced-intensity conditioning regimens.