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-+TCRαß+, CD3+CD25+/CD3HLADR+, TCR αß+ 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.

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.

Acute ataxia in paediatric emergency departments: a multicentre Italian study.

OBJECTIVES: To evaluate the causes and management of acute ataxia (AA) in the paediatric emergency setting and to identify clinical features predictive of an underlying clinically urgent neurological pathology (CUNP). STUDY DESIGN: This is a retrospective medical chart analysis of children (1-18 years) attending to 11 paediatric emergency departments (EDs) for AA in an 8-year period. A logistic regression model was applied to identify clinical risk factors for CUNP. RESULTS: 509 patients (mean age 5.8 years) were included (0.021% of all ED attendances). The most common cause of AA was acute postinfectious cerebellar ataxia (APCA, 33.6%). Brain tumours were the second most common cause (11.2%), followed by migraine-related disorders (9%). Nine out of the 14 variables tested showed an OR >1. Among them, meningeal and focal neurological signs, hyporeflexia and ophthalmoplegia were significantly associated with a higher risk of CUNP (OR=3-7.7, p<0.05). Similarly, the odds of an underlying CUNP were increased by 51% by each day from onset of ataxia (OR=1.5, CI 1.1 to 1.2). Conversely, a history of varicella-zoster virus infection and vertigo resulted in a significantly lower risk of CUNP (OR=0.1 and OR=0.5, respectively; p<0.05). CONCLUSIONS: The most frequent cause of AA is APCA, but CUNPs account for over a third of cases. Focal and meningeal signs, hyporeflexia and ophthalmoplegia, as well as longer duration of symptoms, are the most consistent 'red flags' of a severe underlying pathology. Other features with less robust association with CUNP, such as seizures or consciousness impairment, should be seriously taken into account during AA evaluation.

Activated Carbons: In Vitro Affinity for Aflatoxin B1 and Relation of Adsorption Ability to Physicochemical Parameters.

Affinity in vitro tests were conducted of the efficacy of 17 activated carbons (ACs) in binding aflatoxin B1 from solution. Relationships between adsorption ability and physicochemical parameters of the ACs (surface area, iodine number, methylene blue index, and surface acidity) were tested. Using 5 ml of a 4 µg/ml aqueous solution of aflatoxin B1 and 2 mg of an AC, adsorption abilities ranged from 44.47% to 99.82%. Four ACs showed very high adsorption abilities, binding more than 99% of the available aflatoxin B1. In comparative testing five ACs showed a greater ability to bind aflatoxin B1 than hydrated sodium calcium aluminosilicate (HSCAS). Three ACs also showed high adsorption abilities (ca. 99%) at increasing aflatoxin B1 concentrations (50 and 250 µg/ml) whereas HSCAS adsorption ability greatly declined. With the exception of three ACs, aflatoxin B1 adsorption was significantly correlated with all the physicochemical parameters, confirming a close relationship between molecule trapping and the surface physicochemical adsorption process. The methylene blue index was more reliable than iodine number and surface area in predicting AC adsorptive ability. The results suggested that ACs with a high methylene blue index and low surface acidity have a very high in vitro affinity for aflatoxin B1; however, their efficacy in protecting against aflatoxicosis should be verified further by in vivo tests.