Spanish cohort of VEXAS syndrome: clinical manifestations, outcome of treatments and novel evidences about UBA1 mosaicism.

BACKGROUND: The vacuoles, E1-enzyme, X linked, autoinflammatory and somatic (VEXAS) syndrome is an adult-onset autoinflammatory disease (AID) due to postzygotic UBA1 variants. OBJECTIVES: To investigate the presence of VEXAS syndrome among patients with adult-onset undiagnosed AID. Additional studies evaluated the mosaicism distribution and the circulating cytokines. METHODS: Gene analyses were performed by both Sanger and amplicon-based deep sequencing. Patients' data were collected from their medical charts. Cytokines were quantified by Luminex. RESULTS: Genetic analyses of enrolled patients (n=42) identified 30 patients carrying UBA1 pathogenic variants, with frequencies compatible for postzygotic variants. All patients were male individuals who presented with a late-onset disease (mean 67.5 years; median 67.0 years) characterised by cutaneous lesions (90%), fever (66.7%), pulmonary manifestations (66.7%) and arthritis (53.3%). Macrocytic anaemia and increased erythrocyte sedimentation rate and ferritin were the most relevant analytical abnormalities. Glucocorticoids ameliorated the inflammatory manifestations, but most patients became glucocorticoid-dependent. Positive responses were obtained when targeting the haematopoietic component of the disease with either decitabine or allogeneic haematopoietic stem cell transplantation. Additional analyses detected the UBA1 variants in both haematopoietic and non-haematopoietic tissues. Finally, analysis of circulating cytokines did not identify inflammatory mediators of the disease. CONCLUSION: Thirty patients with adult-onset AID were definitively diagnosed with VEXAS syndrome through genetic analyses. Despite minor interindividual differences, their main characteristics were in concordance with previous reports. We detected for the first time the UBA1 mosaicism in non-haematopoietic tissue, which questions the previous concept of myeloid-restricted mosaicism and may have conceptual consequences for the disease mechanisms.

Drug reexposure in children with severe mucocutaneous reactions.

In pediatric patients, severe cutaneous adverse reactions (SCARs) frequently occur in the course of acute illnesses, mostly infections, which are usually treated with antibiotics or analgesics. The drug provocation test (DPT) is contraindicated in such situations, due to the risk of triggering a new severe reaction. As a consequence, lifelong avoidance is recommended. However, causation is uncertain in most cases. The dilemma arises when avoiding the drug is not harmless for the patient. We have attended three patients who were referred to our pediatric allergy unit with a history of SCAR related in time to simultaneous use of paracetamol and ibuprofen. Medical records and images of the patients were reviewed with the assistance of a dermatologist, and alternative diagnoses were considered in both cases. The ALDEN score for implicated drugs was calculated. After considering a high probability of ibuprofen tolerance and obtaining informed consent from the patients, we performed a sequential allergy workup including in vitro tests, skin tests, and finally DPT in two of the patients, confirming ibuprofen tolerance. In conclusion, although generally contraindicated, DPT may be considered for some useful drugs after careful evaluation of the risk-benefit balance, preceded by a sequential study including in vitro and skin tests.

Acquired Senescent T-Cell Phenotype Correlates with Clinical Severity in GATA Binding Protein 2-Deficient Patients.

GATA binding protein 2 (GATA2) deficiency is a rare disorder of hematopoiesis, lymphatics, and immunity caused by spontaneous or autosomal dominant mutations in the GATA2 gene. Clinical manifestations range from neutropenia, lymphedema, deafness, to severe viral and mycobacterial infections, bone marrow failure, and acute myeloid leukemia. Patients also present with monocytopenia, dendritic cell, B- and natural killer (NK)-cell deficiency. We studied the T-cell and NK-cell compartments of four GATA2-deficient patients to assess if changes in these lymphocyte populations could be correlated with clinical phenotype. Patients with more severe clinical complications demonstrated a senescent T-cell phenotype whereas patients with lower clinical score had undetectable changes relative to controls. In contrast, patients' NK-cells demonstrated an immature/activated phenotype that did not correlate with clinical score, suggesting an intrinsic NK-cell defect. These studies will help us to determine the contribution of T- and NK-cell dysregulation to the clinical phenotype of GATA2 patients, and may help to establish the most accurate therapeutic options for these patients. Asymptomatic patients may be taken into consideration for hematopoietic stem cell transplantation when dysregulation of T-cell and NK-cell compartment is present.

Chip-based capillary electrophoresis profiling of olive pollen extracts used for allergy diagnosis and immunotherapy.

Standardization of protein extracts for clinical purposes represents an important task in order to maintain adequate reactivity, presence of the relevant allergens, and safety among other factors. The main objective of this work was to explore the potential use of a chip-based automated CE system commercially available to analyze several of the most common forms of allergenic extracts from olive pollen used in allergy clinics. These include experimental extracts prepared from olive pollens, in-house reference extracts, extracts designed for skin prick test assays, and a panel of vaccine variants aimed to specific immunotherapy. As a major conclusion of the study, chip-based CE allowed in all cases to determine accurate protein profiles with different degrees of sensitivity, where several allergens (particularly the major olive pollen allergen Ole e 1) were easily recognized. Moreover, several purified allergens were also analyzed by this method, and proposed as specific standards for different purposes. In the present condition, the method can only provide the protein profile of the extracts with respect to a preestablished standard extract, but not allergen identification. However, these and other future developments and applications are discussed.

Quantification and phenotype of regulatory T cells in rheumatoid arthritis according to disease activity score-28.

Here we studied and characterized different peripheral blood (PB) regulatory T cell (Treg) subsets in rheumatoid arthritis (RA) patients and tested the hypothesis that changes in these cells can be linked to the degree of inflammation and relapsing/remission periods. PB cells were examined from RA subjects (n = 60) with different disease activity score-28 (DAS28) and from healthy controls (n = 40). Frequencies of Treg subsets expressing characteristic membrane antigens, FoxP3 or intracellular cytokines were quantified by flow cytometry. We observed a decrease in the percentages of CD4(+)CD25(high), CD4(+)CD25(int), CD4(+)CD25(int/high)FoxP3(+), CD4(+)CD38(+), CD4(+)CD62L(+), CD8(+)CD25(high)CD45RA(+) and CD8(+)CD25(int)CD45RA(+) T cells in PB of RA patients compared to healthy controls. In addition, we found increased percentages of cells expressing membrane/intracellular regulatory antigens such as OX40 (CD134), CD45RB(low) or CTLA-4 (CD152), and a higher proportion of other T cell subsets including CD4(+)CTLA-4(+), CD4(+)IL10(+), CD4(+)CD25(int)IL10(+), CD4(+)CD25(int) TGFbeta(+), CD4(+)CD25(low) TGFbeta(+) and CD8(+)CD28(- ). We show that most of these changes parallel the intensity of inflammation, with lowest or highest values in patients with moderately/very active disease compared to healthy controls and at times to patients with inactive RA. The balance between these cell subsets and their antigen expression would determine the inflammation levels and could thus be linked to the relapsing/remission periods of the disease.