Clinical features and therapeutic challenges of cytopenias belonging to alps and alps-related (ARS) phenotype

Autoimmune Lymphoproliferative Syndrome (ALPS) Disease and ALPS Phenotype: Are They Two Distinct Entities?

Autoimmune lymphoproliferative syndrome (ALPS) is an inherited disorder of lymphocyte homeostasis classically due to mutation of FAS, FASL, and CASP10 genes (ALPS-FAS/CASP10). Despite recent progress, about one-third of ALPS patients does not carry classical mutations and still remains gene orphan (ALPS-U, undetermined genetic defects). The aims of the present study were to compare the clinical and immunological features of ALPS-FAS/CASP10 versus those of ALPS-U affected subjects and to deepen the genetic characteristics of this latter group. Demographical, anamnestic, biochemical data were retrieved from medical record of 46 ALPS subjects. An enlarged panel of genes (next-generation sequencing) was applied to the ALPS-U group. ALPS-U subjects showed a more complex phenotype if compared to ALPS-FAS/CASP10 group, characterized by multiorgan involvement (P = 0.001) and positivity of autoimmune markers (P = 0.02). Multilineage cytopenia was present in both groups without differences with the exception of lymphocytopenia and autoimmune neutropenia that were more frequent in ALPS-U than in the ALPS-FAS/CASP10 group (P = 0.01 and P = 0.04). First- and second-line treatments were able to control the symptoms in 100% of the ALPS-FAS/CASP10 patients, while 63% of ALPS-U needed >2 lines of treatment and remission in some cases was obtained only after target therapy. In the ALPS-U group, we found in 14 of 28 (50%) patients 19 variants; of these, 4 of 19 (21%) were known as pathogenic and 8 of 19 (42%) as likely pathogenic. A characteristic flow cytometry panel including CD3CD4-CD8-+TCRαβ+, CD3+CD25+/CD3HLADR+, TCR αβ+ B220+, and CD19+CD27+ identified the ALPS-FAS/CASP10 group. ALPS-U seems to represent a distinct entity from ALPS-FAS/CASP10; this is relevant for management and tailored treatments whenever available.

Underlying Inborn Errors of Immunity in Patients With Evans Syndrome and Multilineage Cytopenias: A Single-Centre Analysis

Background

Evans syndrome (ES) is a rare disorder classically defined as the simultaneous or sequential presence of autoimmune haemolytic anaemia and immune thrombocytopenia, but it has also been described as the presence of at least two autoimmune cytopenias. Recent reports have shown that ES is often a manifestation of an underlying inborn error of immunity (IEI) that can benefit from specific treatments.

Aims

The aim of this study is to investigate the clinical and immunological characteristics and the underlying genetic background of a single-centre cohort of patients with ES.

Methods

Data were obtained from a retrospective chart review of patients with a diagnosis of ES followed in our centre. Genetic studies were performed with NGS analysis of 315 genes related to both haematological and immunological disorders, in particular IEI.

Results

Between 1985 and 2020, 40 patients (23 men, 17 women) with a median age at onset of 6 years (range 0-16) were studied. ES was concomitant and sequential in 18 (45%) and 22 (55%) patients, respectively. Nine of the 40 (8%) patients had a positive family history of autoimmunity. Other abnormal immunological features and signs of lymphoproliferation were present in 24/40 (60%) and 27/40 (67%) of cases, respectively. Seventeen out of 40 (42%) children fit the ALPS diagnostic criteria. The remaining 21 (42%) and 2 (5%) were classified as having an ALPS-like and an idiopathic disease, respectively. Eighteen patients (45%) were found to have an underlying genetic defect on genes FAS, CASP10, TNFSF13B, LRBA, CTLA4, STAT3, IKBGK, CARD11, ADA2, and LIG4. No significant differences were noted between patients with or without variant and between subjects with classical ES and the ones with other forms of multilineage cytopenias.

Conclusions

This study shows that nearly half of patients with ES have a genetic background being in most cases secondary to IEI, and therefore, a molecular evaluation should be offered to all patients.

Case Report: Deficiency of Adenosine Deaminase 2 Presenting With Overlapping Features of Autoimmune Lymphoproliferative Syndrome and Bone Marrow Failure

Deficiency of adenosine deaminase 2 (DADA2) is an autosomal recessive disease associated with a highly variable clinical presentation, such as vasculitis, inflammation, and hematologic manifestations. Some associations of clinical features can mimic autoimmune lymphoproliferative syndrome (ALPS). We report a case of a female patient who fulfilled the 2009 National Institute of Health revised criteria for ALPS and received a delayed diagnosis of DADA2. During her childhood, she suffered from autoimmune hemolytic anemia, immune thrombocytopenia, and chronic lymphoproliferation, which partially responded to multiple lines of treatments and were followed, at 25 years of age, by pulmonary embolism, septic shock, and bone marrow failure with myelodysplastic evolution. The patient died from the progression of pulmonary disease and multiorgan failure. Two previously unreported variants of gene ADA2/CECR1 were found through next-generation sequencing analysis, and a pathogenic role was demonstrated through a functional study. A single somatic STAT3 mutation was also found. Clinical phenotypes encompassing immune dysregulation and marrow failure should be evaluated at the early stage of diagnostic work-up with an extended molecular evaluation. A correct genetic diagnosis may lead to a precision medicine approach consisting of the use of targeted treatments or early hematopoietic stem cell transplantation.

Primary Immune Regulatory Disorders With an Autoimmune Lymphoproliferative Syndrome-Like Phenotype: Immunologic Evaluation, Early Diagnosis and Management

Primary immune regulatory disorders (PIRD) are associated with autoimmunity, autoinflammation and/or dysregulation of lymphocyte homeostasis. Autoimmune lymphoproliferative syndrome (ALPS) is a PIRD due to an apoptotic defect in Fas-FasL pathway and characterized by benign and chronic lymphoproliferation, autoimmunity and increased risk of lymphoma. Clinical manifestations and typical laboratory biomarkers of ALPS have also been found in patients with a gene defect out of the Fas-FasL pathway (ALPS-like disorders). Following the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA), we identified more than 600 patients suffering from 24 distinct genetic defects described in the literature with an autoimmune lymphoproliferative phenotype (ALPS-like syndromes) corresponding to phenocopies of primary immunodeficiency (PID) (NRAS, KRAS), susceptibility to EBV (MAGT1, PRKCD, XIAP, SH2D1A, RASGRP1, TNFRSF9), antibody deficiency (PIK3CD gain of function (GOF), PIK3R1 loss of function (LOF), CARD11 GOF), regulatory T-cells defects (CTLA4, LRBA, STAT3 GOF, IL2RA, IL2RB, DEF6), combined immunodeficiencies (ITK, STK4), defects in intrinsic and innate immunity and predisposition to infection (STAT1 GOF, IL12RB1) and autoimmunity/autoinflammation (ADA2, TNFAIP3,TPP2, TET2). CTLA4 and LRBA patients correspond around to 50% of total ALPS-like cases. However, only 100% of CTLA4, PRKCD, TET2 and NRAS/KRAS reported patients had an ALPS-like presentation, while the autoimmunity and lymphoproliferation combination resulted rare in other genetic defects. Recurrent infections, skin lesions, enteropathy and malignancy are the most common clinical manifestations. Some approaches available for the immunological study and identification of ALPS-like patients through flow cytometry and ALPS biomarkers are provided in this work. Protein expression assays for NKG2D, XIAP, SAP, CTLA4 and LRBA deficiencies and functional studies of AKT, STAT1 and STAT3 phosphorylation, are showed as useful tests. Patients suspected to suffer from one of these disorders require rapid and correct diagnosis allowing initiation of tailored specific therapeutic strategies and monitoring thereby improving the prognosis and their quality of life.

Sirolimus is effective in autoimmune lymphoproliferative syndrome-type III: A pedigree case report with homozygous variation PRKCD

Autoimmune lymphoproliferative syndrome (ALPS) usually presents in childhood with fever, nonmalignant splenomegaly, and lymphadenopathy along with cytopenia, which is caused by mutations in the FAS apoptotic pathway. The TCRαβ + CD4/CD8 double-negative T cells (DNT), one of required criteria of ALPS, will rise markedly in ALPS. Human Protein kinase C delta (PRKCD) deficiency (OMIM # 615559) was recently identified to be causative for an ALPS-type III with significant B-cell proliferation particularly of immature B cells. We report a pedigree homozygous variation of PRKCD gene (c.36T>G, p. Y12X) which presented with refractory cytopenia, splenomegaly, and polarization of DNT/regulatory T cells (Treg) axis. After repeated recurrence, the patient was treated with mTOR inhibitor sirolimus, which had a safety mechanism and specifically rebalance the DNT/Treg axis. The patient's hemoglobin and clinical condition improved gradually by the application of sirolimus (1.5 mg/m², actual blood concentration 4.27-10.3 ng/l). Homozygous variation in PRKCD may lead to typical ALPS clinical manifestations. Targeting DNT/Treg axis, use of sirolimus in such patients may help to achieve good clinical control.

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.

Defective FAS-Mediated Apoptosis and Immune Dysregulation in Gaucher Disease

BACKGROUND

Gaucher disease (GD) is a rare disorder characterized by defective function of β-glucocerebrosidase, which leads to progressive accumulation of its substrate in various organs, particularly the mononuclear phagocyte system. Hepatosplenomegaly and cytopenia represent the disease's most common features, but patients with GD also show hyperinflammation, hypergammaglobulinemia, and immune dysregulation involving B, T, and natural killer cells. As clinical phenotype can be underhand, symptoms can overlap with autoimmune lymphoproliferative syndrome (ALPS) or other ALPS-like disorders.

OBJECTIVE

To evaluate the ALPS-like immunological pattern and apoptosis function in patients with GD.

METHODS

We evaluated lymphocyte subsets and immunophenotypic and serological features of ALPS (double-negative T cells [DNTs], B220+DNTs, CD27+, T-reg/HLA-DR ratio, IL-10, IL-18, vitamin B12) in a population of patients with GD. Moreover, we tested FAS/TRAIL-induced apoptosis and CASP8/CASP10/PARP function in patients showing an immune-dysregulation pattern.

RESULTS

A total of 41 patients (33 treated, 8 treatment-naïve) were studied. Nine (21%) and 7 (17%) of 41 patients had high DNT and B220+DNT counts, respectively. Overall, 10 of 41(24%) patients showed immunological features suggestive of ALPS that were more frequent in treatment-naïve subjects (P = .040 vs P = .031) and in those with early onset of the disease (P = .046 vs P = .011), respectively. FAS-induced apoptosis and caspase activation were further evaluated in these 10 patients and were found to be defective in 7 of them.

CONCLUSIONS

We show that patients with GD may have ALPS-like features and FAS-mediated apoptosis defects that are more pronounced in treatment-naïve subjects and in patients with early onset of the disease. Therefore, diagnostic workup of patients with an ALPS-like phenotype should include screening for GD.