Genetic screening of children with marrow failure. The role of primary Immunodeficiencies.

The differential diagnosis of marrow failure (MF) is crucial in the diagnostic work-up, since genetic forms require specific care. We retrospectively studied all patients with single/multi-lineage MF evaluated in a single-center to identify the type and incidence of underlying molecular defects. The diepoxybutane test was used to screen Fanconi Anemia. Other congenital MFs have been searched using Sanger and/or Next Generation Sequencing analysis, depending on the available tools over the years. Between 2009-2019, 97 patients (aged 0-32 years-median 5) with single-lineage (29%) or multilineage (68%) MF were evaluated. Fifty-three (54%) and 28 (29%) were diagnosed with acquired and congenital MF, respectively. The remaining 16 (17%), with trilinear (n=9) and monolinear (n=7) MF, were found to have an underlying primary immunodeficiency (PID) and showed clinical and biochemical signs of immune-dysregulation in 10/16 (62%) and in 14/16 (87%) of cases, respectively. Clinical signs were also found in 22/53 (41%) and 8/28 (28%) patients with idiopathic and classical cMF, respectively. Eight out of 16 PIDs patients were successfully transplanted, four received immunosuppression, two did not require treatment, and the remaining two died. We show that patients with single/multi-lineage MF may have underlying PIDs in a considerable number of cases and that MF may represent a relevant clinical sign in patients with PIDs, thus widening their clinical phenotype. An accurate immunological work-up should be performed in all patients with MF, and PID-related genes should be considered when screening MF in order to identify disorders that may receive targeted treatments and/or appropriate conditioning regimens before transplant.

Late-onset and long-lasting autoimmune neutropenia: an analysis from the Italian Neutropenia Registry.

Primary autoimmune neutropenia (pAN) is typified by onset in early infancy and a mild/moderate phenotype that resolves within 3 years of diagnosis. In contrast, secondary AN is classically an adult disease associated with malignancy, autoimmunity, immunodeficiency, viral infection, or drugs. This study describes a cohort of 79 children from the Italian Registry who, although resembling pAN, did not fully match the criteria for pAN because neutropenia either appeared after age 5 years (LO-Np) or lasted longer than 3 years (LL-Np). These 2 categories compared with classical pAN showed a far inferior rate of resolution (P < .001), lower severity of neutropenia (P = .03), leukopenia (P < .001), lymphopenia (P < .001) with low B+ (P = .001), increased need of granulocyte colony-stimulating factor (P = .04), and increased frequency of autoimmunity over the disease course (P < .001). A paired comparison between LO-Np and LL-Np suggested that LO-Np had a lower rate of resolution (P < .001) and lower white blood cell (P < .001) and lymphocyte (P < .001) values, higher occurrence of apthae (P = .008), and a stronger association with autoimmune diseases/markers (P = .001) than LL-Np, thus suggesting a more pronounced autoimmune signature for LO-Np. A next-generation sequencing panel applied in a small subgroup of LO-Np and LL-Np patients identified variants related to immune dysregulations. Overall, these findings indicate that there are important differences among pAN LL-Np and LO-Np. Forms rising after 3 years of age, with low tendency to resolution, require tight monitoring and extensive immune investigations aimed to early identify underlying immunologic disease.

Defective FAS-Mediated Apoptosis and Immune Dysregulation in Gaucher Disease.

BACKGROUND: Gaucher disease (GD) is a rare disorder characterized by defective function of ß-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.

Unusual Late-onset Enteropathy in a Patient With Lipopolysaccharide-responsive Beige-like Anchor Protein Deficiency.

In recent years, monogenic causes of immune dysregulation syndromes, with variable phenotypes, have been documented. Mutations in the lipopolysaccharide-responsive beige-like anchor (LRBA) protein are associated with common variable immunodeficiency, autoimmunity, chronic enteropathy, and immune dysregulation disorders. The LRBA protein prevents degradation of cytotoxic T-lymphocyte antigen 4 (CTLA4) protein, thus inhibiting immune responses. Both LRBA and CTLA4 deficiencies usually present with immune dysregulation, mostly characterized by autoimmunity and lymphoproliferation. In this report, we describe a patient with an atypical clinical onset of LRBA deficiency and the patient's response to abatacept, a fusion protein-drug that mimics the action of CTLA4.

FAS-mediated apoptosis impairment in patients with ALPS/ALPS-like phenotype carrying variants on CASP10 gene.

Autoimmune lymphoproliferative syndrome (ALPS) is a congenital disorder that results in an apoptosis impairment of lymphocytes, leading to chronic lymphoproliferation and autoimmunity, mainly autoimmune cytopenias. FAS gene defects are often responsible for the disease, the phenotype of which can vary from asymptomatic/mild forms to severe disease. More rarely, defects are associated to  other genes involved in apoptosis pathway, such as CASP10. Few data are available on CASP10-mutated patients. To date, two CASP10 mutations have been recognized as pathogenic (I406L and L258F) and others have been reported with controversial result on their pathogenicity (V410l, Y446C) or are known to be polymorphic variants (L522l). In this study, we evaluated apoptosis function in patients with an ALPS/ALPS-like phenotype carrying CASP10 variants. Molecular findings were obtained by next generation sequencing analysis of genes involved in immune dysregulation syndromes. Functional studies were performed after inducing apoptosis by FAS-ligand/TRIAL stimulation and analysing cell death and the function of CASP10, CASP8 and PARP proteins. We identified 6 patients with an ALPS (n = 2) or ALPS-like (n = 4) phenotype, carrying I406L (n = 1),V410l (n = 2),Y446C (n = 1) heterozygous CASP10 variants or the L522l polymorphisms (n = 2) associated with another polymorphic homozygote variant on CASP8 or a compound heterozygous mutation on TNFRSF13C. Apoptosis was impaired in all patients showing that such variants may play a role in the development of clinical phenotype.

Idiopathic neutropenia of infancy: Data from the Italian Neutropenia Registry.

Autoimmune neutropenia of infancy (AIN) is characterized by low risk of severe infection, tendency to spontaneously resolve and typically onset at ≤4-5 years of age; it is due to auto-antibodies whose detection is often difficult. In case of negativity of 4 antineutrophils autoantibody tests, after having excluded ethnic, postinfection, drug induced, or congenital neutropenia, according to the Italian guidelines the patients will be defined as affected by "idiopathic neutropenia" (IN). We describe the characteristics of 85 IN patients enrolled in the Italian neutropenia registry: they were compared with 336 children affected by AIN. The 2 groups were clinically very similar and the main differences were detection age (later in IN), length of disease (longer in IN) and, among recovered patients, age of spontaneous recovery: the median age at resolution was 2.13 years in AINs and 3.03 years in INs (P = .00002). At bivariate analysis among AIN patients earlier detection age (P = .00013), male sex (P = .000748), absence of leucopenia (P = .0045), and absence of monocytosis (P = .0419) were significantly associated with earlier recovery; in the IN group only detection age (P = .013) and absence of monocytosis (P = .0333) were significant. At multivariate analysis detection age and absence of monocytosis were independently significant (P = 6.7e-05 and 4.4e-03, respectively) in the AIN group, whereas in the IN group only detection age stayed significant (P = .013).

Mycophenolate mofetil and Sirolimus as second or further line treatment in children with chronic refractory Primitive or Secondary Autoimmune Cytopenias: a single centre experience.

The management of refractory autoimmune cytopenias in childhood is challenging due to the lack of established evidence on escalating treatments. The long-term efficacy of immunosuppressive drugs was evaluated in children with refractory autoimmune cytopenias referred to the Haematology Unit of the Gaslini Children's Hospital between 2001 and 2014. Patients were grouped into three categories: autoimmune lymphoproliferative syndrome (ALPS), ALPS-related syndrome (at least one absolute/primary additional criterion for ALPS) and primary autoimmune cytopenia (PAC, cytopenia with no other immunological symptoms/signs). Fifty-eight children (aged 1-16 years) entered the study: 12 were categorized with ALPS, 24 were ALPS-related and 22 had PAC. Five didn't receive treatment. Fifty-three were initially treated with steroids/intravenous immunoglobulin. Fourteen responded, whereas 39 did not. Of these 39 patients, 34 (87%) received mycophenolate mofetil (MMF) as second/further-line treatment and 22 (65%) responded. Within these 34 subjects, ALPS patients responded better (11/11, 100%) than the two other groups pooled together (11/23, 48%; P = 0·002). Sirolimus was given as second/further-line treatment to 16 children, and 12 (75%) responded, including 8 who previously failed MMF therapy. Median follow-up was 3·46 years. MMF and Sirolimus were well-tolerated and enabled partial/complete and sustained remission in most children. These drugs may be successfully and safely used in children with refractory autoimmune cytopenias with or without ALPS/ALPS-related disorders and may represent a valid second/further line option.

p38 Mitogen-activated protein kinase inhibition enhances in vitro erythropoiesis of Fanconi anemia, complementation group A-deficient bone marrow cells.

Bone marrow failure in Fanconi anemia (FA) has been linked in part to overproduction of inflammatory cytokines, to which FA stem and progenitor cells are hypersensitive. In cell lines and murine models p38 mitogen-activated protein kinase (MAPK)-dependent tumor necrosis factor α (TNF-α) overexpression can be induced by the Toll-like receptors (TLRs) 4 and 7/8 ligands Lipopolysaccharide (LPS) and R848. Ex vivo exposure of FA stem cells to TNF-α suppresses their replication and selects preleukemic clones. Here we show that inhibition of p38 MAPK also reduces TLR4 and 7/8-mediated TNF-α production in primary human FA complementation group A (FANCA)-deficient monocytes from nine patients and demonstrate that, while p38 MAPK inhibition also enhances clonal growth of FANCA-deficient erythroid progenitors, the effect was mediated indirectly by the influence of the inhibitor on auxiliary cells, not erythroid colony-forming units themselves. Taken together, these results support the view that inhibition of the p38 MAPK pathway in monocytes may improve hematopoiesis in FANCA patients.

Poikiloderma with neutropenia: a case report and review of the literature.

Poikiloderma with neutropenia (PN, OMIM 604173) is a rare autosomal-recessive genodermatosis. Mutations in the C16orf57 gene have been recently identified as the cause. Here we describe a new case of PN in a white patient, review the literature, and point out the attention on importance of differential diagnosis.

Pegfilgrastim in children with severe congenital neutropenia.

Two pediatric patients affected by severe congenital neutropenia (SCN) were treated with 100 mcg/L/dose every 9-12 days within a pilot study (Observatory of the Italian Ministry of Health, Eudract Code 2005-003096-20) on the use of pegfilgrastim in patients with chronic neutropenia. Both children increased their absolute neutrophil count, reduced their infectious load, and improved their quality of life. Serum concentrations of G-CSF observed in pegfilgrastim mirrored those seen in filgrastim. These data suggest that pegfilgrastim may be beneficial in SCN patients with an exposure of hematopoietic cells to G-CSF similar to that on filgrastim.

Etanercept as a salvage treatment for refractory aplastic anemia.

About 10-15% of patients with acquired aplastic anemia (AAA) have resistant/recurrent disease not eligible for standard treatment like hematopoietic stem cell transplantation and/or combined immunosuppression. We report a 17-year-old male with an 11 years history of AAA who, after two courses of immunosuppression, was red cell transfusion-dependent, severely thrombocytopenic, refractory to platelet transfusion, had iron overload and post-transfusion HCV infection. This patient achieved transfusion independence from platelets and normalized Hb after treatment with the anti-TNF agent Etanercept. Over a 12 months follow-up he experienced only transient increase of liver transaminases.