Epigenetic and immunological indicators of IPEX disease in subjects with FOXP3 gene mutation.

BACKGROUND: Forkhead box protein 3 (FOXP3) is the master transcription factor in CD4+CD25hiCD127lo regulatory T (Treg) cells. Mutations in FOXP3 result in IPEX (immune dysregulation, polyendocrinopathy, enteropathy, X-linked) syndrome. Clinical presentation of IPEX syndrome is broader than initially described, challenging the understanding of the disease, its evolution, and treatment choice. OBJECTIVE: We sought to study the type and extent of immunologic abnormalities that remain ill-defined in IPEX, across genetic and clinical heterogeneity. METHODS: We performed Treg-cell-specific epigenetic quantification and immunologic characterization of severe "typical" (n = 6) and "atypical" or asymptomatic (n = 9) patients with IPEX. RESULTS: Increased number of cells with Treg-cell-Specific Demethylated Region demethylation in FOXP3 is a consistent feature in patients with IPEX, with (1) highest values in those with typical IPEX, (2) increased values in subjects with pathogenic FOXP3 but still no symptoms, and (3) gradual increase over the course of disease progression. Large-scale profiling using Luminex identified plasma inflammatory signature of macrophage activation and TH2 polarization, with cytokines previously not associated with IPEX pathology, including CCL22, CCL17, CCL15, and IL-13, and the inflammatory markers TNF-α, IL-1A, IL-8, sFasL, and CXCL9. Similarly, both Treg-cell and Teff compartments, studied by Mass Cytometry by Time-Of-Flight, were skewed toward the TH2 compartment, especially in typical IPEX. CONCLUSIONS: Elevated TSDR-demethylated cells, combined with elevation of plasmatic and cellular markers of a polarized type 2 inflammatory immune response, extends our understanding of IPEX diagnosis and heterogeneity.

SARS-CoV-2 Infection Presenting as Acute Chest Syndrome in a Child With Hemoglobin SD-Los Angeles Disease: A Case Report and Review of Literature.

Hemoglobin D-Los Angeles is a variant of hemoglobin that can polymerize in the deoxygenated state. When co-inherited with Hemoglobin S (HbSD-Los Angeles disease) a severe sickling syndrome similar to HbSS can result. Corona virus infectious disease 2019 (COVID-19) is caused by the severe acute respiratory syndrome-corona virus-2. It has been associated with acute chest syndrome (ACS) in individuals with sickle cell disease (SCD), but this complication has not previously been reported in patients with HbSD-Los Angeles. Dexamethasone has been shown to improve outcomes in non-SCD patients with severe acute respiratory syndrome-corona virus-2 pneumonia or acute respiratory distress syndrome; however, its use in SCD patients with ACS is controversial due to a reported increased risk of complications including vaso-occlusive painful episodes. Herein, we reported a patient with HbSD-Los Angeles and COVID-19-associated ACS whom we treated with dexamethasone without transfusion. The patient experienced a rapid recovery without sequelae from steroid use. To further evaluate the use of steroids, we conducted a literature review focusing on the management of pediatric SCD patients with COVID-19-associated ACS. We identified a total of 39 pediatric patients with SCD and COVID-19, of whom 21 (54%) had ACS. Packed red blood cell transfusion (n=11), exchange transfusion (n=4), or a combination of exchange transfusion and packed red blood cell transfusion (n=4) were the most frequently reported treatment, with hydroxychloroquine (n=5), remdesivir (n=1), and tocilizumab (n=1) also being reported. Three patients were treated with dexamethasone. All patients recovered and no adverse outcomes from steroid use were reported. Even though transfusion is considered the standard of care for children with ACS and steroids are not routinely recommended, our experience suggested that COVID-19-associated ACS may be an important exception, especially for patients who refuse transfusion or are in resource-poor nations where blood transfusions may not be readily available. Further studies are warranted to confirm these observations.