Optimal Management of Autoimmune Lymphoproliferative Syndrome in Children

Autoimmune lymphoproliferative immunodeficiencies (ALPIDs): A proposed approach to redefining ALPS and other lymphoproliferative immune disorders

Chronic nonmalignant lymphoproliferation and autoimmune cytopenia are relevant manifestations of immunohematologic diseases of childhood. Their diagnostic classification is challenging but important for therapy. Autoimmune lymphoproliferative syndrome (ALPS) is a genetically defined inborn error of immunity combining these manifestations, but it can explain only a small proportion of cases. Diagnostic categories such as ALPS-like disease, common variable immunodeficiency, or Evans syndrome have therefore been used. Advances in genetics and increasing availablity of targeted therapies call for more therapy-oriented disease classification. Moreover, recent discoveries in the (re)analysis of genetic conditions affecting FAS signaling ask for a more precise definition of ALPS. In this review, we propose the term autoimmune lymphoproliferative immunodeficiencies for a disease phenotype that is enriched for patients with genetic diseases for which targeted therapies are available. For patients without a current molecular diagnosis, this term defines a subgroup of immune dysregulatory disorders for further studies. Within the concept of autoimmune lymphoproliferative immunodeficiencies, we propose a revision of the ALPS classification, restricting use of this term to conditions with clear evidence of perturbation of FAS signaling and resulting specific biologic and clinical consequences. This proposed approach to redefining ALPS and other lymphoproliferative conditions provides a framework for disease classification and diagnosis that is relevant for the many specialists confronted with these diseases.

Repurposable Drugs for Immunotherapy and Strategies to Find Candidate Drugs

Conventional drug discovery involves significant steps, time, and expenses; therefore, novel methods for drug discovery remain unmet, particularly for patients with intractable diseases. For this purpose, the drug repurposing method has been recently used to search for new therapeutic agents. Repurposed drugs are mostly previously approved drugs, which were carefully tested for their efficacy for other diseases and had their safety for the human body confirmed following careful pre-clinical trials, clinical trials, and post-marketing surveillance. Therefore, using these approved drugs for other diseases that cannot be treated using conventional therapeutic methods could save time and economic costs for testing their clinical applicability. In this review, we have summarized the methods for identifying repurposable drugs focusing on immunotherapy.

[Autoimmune lymphoproliferative syndrome: a case report]

Autoimmune lymphoproliferative syndrome (ALPS) is a rare genetic disorder of lymphocyte homeostasis, resulting from mutations in the Fas apoptotic pathway. It is characterized by non-infectious and non-malignant chronic lymphoproliferation and an increased risk of lymphoid malignancy. The diagnosis of this condition usually combines chronic lymphadenopathy and/or splenomegaly exceeding 6 months, autoimmune cytopenias, with an elevated level of CD3+CD4-CD8- Tαβ lymphocytes, known as "double-negative" T cells. Differential diagnosis includes infections, autoimmune diseases or malignancies. Although clinical examination and laboratory tests are highly suggestive, this disease goes widely unrecognized. We here report, for the first time, the case of ALPS, a Moroccan patient, and aged 8 years, with recurrent fever, splenomegaly and adenopathies. Paraclinical examinations revealed chronic pancytopenia, higher than normal Tαβ double negative lymphocytes, hypergammaglobulinemia, and elevated serum levels of soluble FAS ligand. The diagnosis of ALPS was made. First-line treatment included corticosteroids and immunoglobulins. Then the patient received mycophenolate followed by Sirolimus. This treatment resulted in better clinical and laboratory tests results. Our aim is to raise awareness of this rare condition, which may be under-diagnosed, among physicians.

Lymphoproliferation in Inborn Errors of Immunity: The Eye Does Not See What the Mind Does Not Know

Inborn errors of immunity (IEIs) are a group of heterogeneous disorders characterized by a broad clinical spectrum of recurrent infections and immune dysregulation including autoimmunity and lymphoproliferation (LP). LP in the context of IEI may be the presenting feature of underlying immune disorder or may develop during the disease course. However, the correct diagnosis of LP in IEI as benign or malignant often poses a diagnostic dilemma due to the non-specific clinical features and overlapping morphological and immunophenotypic features which make it difficult to treat. There are morphological clues to LP associated with certain IEIs. A combination of ancillary techniques including EBV-associated markers, flow cytometry, and molecular assays may prove useful in establishing a correct diagnosis in an appropriate clinical setting. The present review attempts to provide comprehensive insight into benign and malignant LP, especially the pathogenesis, histological clues, diagnostic strategies, and treatment options in patients with IEIs.

Autoimmune lymphoproliferative syndrome identified through reverse phenotyping

Autoimmune lymphoproliferative syndrome (ALPS) is a chronic non-malignant lymphoproliferative disorder caused by mutations in the genes involved in programmed cell death. It is inherited as an autosomal dominant pattern with variable penetrance. In this paper we present the first report of a Macedonian family with ALPS, caused by a novel heterozygous variant in the FAS gene. The next generation sequencing (NGS) analysis in a patient with splenomegaly, suspected for hereditary spherocytosis, showed presence of the FAS c.913dupA, p.Thr305AsnfsTer16 variant. The same variant was present in the patient's mother, but not in the mother's parents (proband's grandparents). Thus, the pathogenic FAS variant has arisen as a de novo event in the proband's mother. Later, analysis of the newborn affected sister showed presence of the same FAS variant. Additional clinical and laboratory investigations in the proband and her sister confirmed the presence of specific biomarkers for ALPS. A first-line NGS analysis allows identification of the genetic defect and initiation of appropriate clinical examinations to promptly establish the clinical diagnosis in patients with rare diseases. Reverse phenotyping in our case provided a prompt and accurate diagnosis and early initiation of specific therapy.

The challenge of early diagnosis of autoimmune lymphoproliferative syndrome in children with suspected autoinflammatory/autoimmune disorders

OBJECTIVES

To test the usefulness of an extended panel of lymphocyte subsets (LS) in combination with Oliveira's diagnostic criteria for the identification of autoimmune lymphoproliferative syndrome (ALPS) in children referred to a pediatric rheumatology center.

METHODS

patients referred from 2015 to 2018 to our Rheumatology Unit for an autoimmune or autoinflammatory condition were retrospectively analyzed. Oliveira's required criteria (chronic lymphoproliferation and elevated DNT) were applied as first screening. Flow cytometry study included double negative CD4-CD8-TCR αβ+T lymphocytes (DNT), CD25+CD3+, HLA-DR+CD3+T cells, B220+T cells, and CD27+B cells. Data were analyzed with an univariate logistic regression analysis, followed by a multivariate analysis. Sensitivity and specificity of the Oliveira's required criteria were calculated.

RESULTS

264 patients were included in the study and classified as: i) autoimmune diseases (26); ii) juvenile idiopathic arthritis (JIA) (35) iii) monogenic systemic autoinflammatory disease (SAID) (27); iv) PFAPA syndrome (100); v) systemic undefined recurrent fever (SURF) (45); vi) undetermined-SAID (14); vii) ALPS (17). Oliveira's required criteria displayed a sensitivity of 100% and specificity of 79%. When compared with other diseases the TCRαβ+B220+ lymphocytes were significantly increased in ALPS patients. The multivariate analysis revealed 5 clinical/laboratory parameters positively associated to ALPS: splenomegaly, female gender, arthralgia, elevated DNT and TCRαβ+B220+lymphocytes.

CONCLUSIONS

Oliveira's required criteria are useful for the early suspicion of ALPS. TCRαβ+B220+ lymphocytes should be added in the diagnostic work-up of patients referred to pediatric rheumatology unit for a suspected autoimmune or autoinflammatory condition, providing a relevant support in the early diagnosis of ALPS.

The Role of mTOR Inhibitors in Hematologic Disease: From Bench to Bedside

The mTOR pathway plays a central role in many cellular processes, such as cellular growth, protein synthesis, glucose, and lipid metabolism. Aberrant regulation of mTOR is a hallmark of many cancers, including hematological malignancies. mTOR inhibitors, such as Rapamycin and Rapamycin analogs (Rapalogs), have become a promising class of agents to treat malignant blood diseases-either alone or in combination with other treatment regimens. This review highlights experimental evidence underlying the molecular mechanisms of mTOR inhibitors and summarizes their evolving role in the treatment of hematologic disease, including leukemia, lymphoma, myeloma, immune hemocytopenia, and graft-versus-host disease (GVHD). Based on data presented in this review, we believe that mTOR inhibitors are becoming a trusted therapeutic in the clinical hematologist's toolbelt and should be considered more routinely in combination therapy for the management of hematologic disease.

Case Report: A Novel Pathogenic Missense Mutation in FAS: A Multi-Generational Case Series of Autoimmune Lymphoproliferative Syndrome

Autoimmune Lymphoproliferative Syndrome (ALPS), commonly caused by mutations in the FAS gene, is a disease with variable penetrance. Subjects may be asymptomatic, or they may present with lymphadenopathy, splenomegaly, cytopenias, or malignancy. Prompt recognition of ALPS is needed for optimal management. We describe a multi-generational cohort presenting with clinical manifestations of ALPS, and a previously unreported heterozygous missense variant of uncertain significance in FAS (c.758G >T, p.G253V), located in exon 9. Knowledge of the underlying genetic defect permitted prompt targeted therapy to treat acute episodes of cytopenia. This cohort underscores the importance of genetic testing in subjects with clinical features of ALPS and should facilitate the reclassification of this variant as pathogenic.

Autoimmune Lymphoproliferative Syndrome in Children with Nonmalignant Organomegaly, Chronic Immune Cytopenia, and Newly Diagnosed Lymphoma

This study investigated the frequency of and predictive factors for autoimmune lymphoproliferative syndrome (ALPS) in children with lymphoma, chronic immune cytopenia, and nonmalignant organomegaly. Thirty-four children with suspected ALPS (n=13, lymphoma; n=12, immune cytopenia; n=9, nonmalignant organomegaly) were included. Double-negative T-cells, lymphocyte apoptosis, and genetic findings were analyzed. Patients were stratified into two groups as proven/probable ALPS and clinically suspected patients according to the ALPS diagnostic criteria. Of the 34 patients, 18 (53%) were diagnosed with proven/probable ALPS. One patient had a mutation (c.652-2A>C) in the FAS gene. The remaining 16 (47%) patients were defined as clinically suspected patients. Predictive factors for ALPS were anemia and thrombocytopenia in patients with lymphoma, splenomegaly and lymphadenopathy in patients with immune cytopenia, and young age in patients with nonmalignant organomegaly. ALPS may not be rare in certain risk groups. Our study indicates that screening for ALPS may be useful in children having lymphoma with cytopenia at diagnosis, in those having nonmalignant organomegaly with immune cytopenia, and in those having chronic immune thrombocytopenic purpura or autoimmune hemolytic anemia with organomegaly developing during follow-up.

Update in Primary Immunodeficiencies

Primary immunodeficiencies (PIDs) are inherited disorders classically characterized by increased susceptibility to infections. Nevertheless, in the last two decades, genomic analysis (such as NGS) coupled with biochemical and cellular studies led to a more accurate definition for a growing number of novel genetic disorders associated with PIDs. This revealed new aspects of the immune system and its function and regulation within these diseases. In particular, it has been clarified that the clinical features of PIDs are much broader that originally thought and extend beyond an increased susceptibility to infections. More specifi- cally, immune dysregulation is very often described in novel characterized PIDs and can lead to multiple autoimmune diseases, lymphoproliferation and malignancies. If not promptly diagnosed, these could negatively impact patient's prognosis. The aim of this review is to increase the awareness of recently discovered PIDs, characterized predominantly by immune dysregulation phenotypes. Findings highlighted in this review  suggest screening for immunodeficiency in patients with lymphoproliferation or early onset/multiple autoimmune diseases. Prompt diagnosis would potentially allow most successful treatment and clinical outcome for patients with PIDs.

Treatment-recalcitrant laryngeal sarcoidosis responsive to sirolimus

A 15-year-old girl presented with gradual-onset dysphonia and dysphagia. Laryngoscopy revealed significant supraglottic airway obstruction with swelling of both the epiglottis and arytenoids. After emergency tracheostomy, biopsy of the epiglottis revealed lymphoid hyperplasia with focal non-necrotising granulomata, leading to a presumed diagnosis of laryngeal sarcoidosis. Treatment with prednisolone and methotrexate produced minimal clinical improvement. A switch to sirolimus was followed by significant reduction in the laryngeal swelling, allowing decannulation of the tracheostomy. Treatment with sirolimus should be considered as a steroid sparing agent in laryngeal sarcoidosis, particularly in the presence of lymphoid hyperplasia on biopsy.

An updated review on phenocopies of primary immunodeficiency diseases

Primary immunodeficiency diseases (PIDs) refer to a heterogenous group of disorders characterized clinically by increased susceptibility to infections, autoimmunity and increased risk of malignancies.

These group of disorders present with clinical manifestations similar to PIDs with known genetic defects but have either no genetic defect or have a somatic mutation and thus have been labelled as “Phenocopies of PIDs”. These diseases have been further subdivided into those associated with somatic mutations and those associated with presence of auto-antibodies against various cytokines.

In this review, we provide an update on clinical manifestations, diagnosis and management of these diseases.

Autoimmune lymphoproliferative syndrome: more than a FAScinating disease

Autoimmune lymphoproliferative syndrome (ALPS) is an inherited syndrome characterized by abnormal lymphocyte survival caused by failure of apoptotic mechanisms to maintain lymphocyte homeostasis. This failure leads to the clinical manifestations of non-infectious and non-malignant lymphadenopathy, splenomegaly, and autoimmune pathology, most commonly, autoimmune cytopenias. Since ALPS was first characterized in the early 1990s, insights in disease biology have improved both diagnosis and management of this syndrome. Sirolimus is the best-studied and most effective corticosteroid-sparing therapy for ALPS and should be considered first-line for patients in need of chronic treatment. This review highlights practical clinical considerations for the diagnosis and management of ALPS. Further studies could reveal new proteins and regulatory pathways that are critical for lymphocyte activation and apoptosis.

Intravenous Immunoglobulin in the Treatment of Hematologic Disorders in Pediatrics

Intravenous immunoglobulin (IVIG) is pooled immunoglobulin G derived from human blood donors. It was introduced in the early 1980s to treat immunodeficiency disorders. Since then, its use has expanded to other fields such as neurology, rheumatology, and hematology. IVIG has been used to provide passive immunity in qualitative and quantitative immunoglobulin disorders, to neutralize antibodies in immune-mediated diseases, and as an immune modulatory agent. The difficulty of producing IVIG in high quantities, in addition to a growing list of "off-label" indications, has resulted in a worldwide shortage and increase in cost. From a pediatric hematology perspective, IVIG is considered an appropriate therapeutic option in autoimmune cytopenias, sometimes coadministrated with steroids. Its use in other hematologic disorders is questionable, and there is not sufficient evidence to recommend it. This article provides clear information to the general pediatrician about indications for IVIG therapy in children with hematologic disorders. [Pediatr Ann. 2017;46(1):e13-e18.].