Combination therapy with tacrolimus and betamethasone for a patient with X-linked auto-immune enteropathy

Impact of Early Corticosteroids on Preventing Clinical Deterioration in Non-critically Ill Patients Hospitalized with COVID-19: A Multi-hospital Cohort Study

INTRODUCTION

While guidelines stronglyrecommend dexamethasone in critical COVID-19, the optimal threshold to initiate corticosteroids in non-critically ill patients with COVID-19 remains unclear. Using data from a state-wide COVID-19 registry, we evaluated the effectiveness of early corticosteroids for preventing clinical deterioration among non-critically ill patients hospitalized for COVID-19 and receiving non-invasive oxygen therapy.

METHODS

This was a target trial using observational data from patients hospitalized for COVID-19 at 39 hospitals participating in the MI-COVID19 registry between March 16, 2020 and August 24, 2020. We studied the impact of corticosteroids initiated within 2 calendar days of hospitalization ("early steroids") versus no early steroids among non-ICU patients with laboratory-confirmed SARS-CoV2 receiving non-invasive supplemental oxygen therapy. Our primary outcome was a composite of in-hospital mortality, transfer to intensive care, and receipt of invasive mechanical ventilation. We used inverse probability of treatment weighting (IPTW) and propensity score-weighted regression to measure the association of early steroids and outcomes.

RESULTS

Among 1002 patients meeting study criteria, 231 (23.1%) received early steroids. After IPTW, to balance potential confounders between the treatment groups, early steroids were not associated with a decrease in the composite outcome (aOR 1.1, 95%CI 0.8-1.6) or in any components of the primary outcome.

CONCLUSION

We found no evidence that early corticosteroid therapy prevents clinical deterioration among hospitalized non-critically ill COVID-19 patients receiving non-invasive oxygen therapy. Further studies are needed to determine the optimal threshold for initiating corticosteroids in this population.

FOXP3 and Tip60 Structural Interactions Relevant to IPEX Development Lead to Potential Therapeutics to Increase FOXP3 Dependent Suppressor T Cell Functions

Regulatory T (Treg) cells play a role in the maintenance of immune homeostasis and are critical mediators of immune tolerance. The Forkhead box P3 (FOXP3) protein acts as a regulator for Treg development and function. Mutations in the FOXP3 gene can lead to autoimmune diseases such as Immunodysregulation, polyendocrinopathy, enteropathy, and X-linked (IPEX) syndrome in humans, often resulting in death within the first 2 years of life and a scurfy like phenotype in Foxp3 mutant mice. We discuss biochemical features of the FOXP3 ensemble including its regulation at various levels (epigenetic, transcriptional, and post-translational modifications) and molecular functions. The studies also highlight the interactions of FOXP3 and Tat-interacting protein 60 (Tip60), a principal histone acetylase enzyme that acetylates FOXP3 and functions as an essential subunit of the FOXP3 repression ensemble complex. Lastly, we have emphasized the role of allosteric modifiers that help stabilize FOXP3:Tip60 interactions and discuss targeting this interaction for the therapeutic manipulation of Treg activity.

Quantitative assessment of betamethasone dual-acting formulation in urine of patients with rheumatoid arthritis and ankylosing spondylitis after single-dose intramuscular administration and its application to long-term pharmacokinetic study

Quantitative evaluation and assessment of pharmacokinetic parameters of Diprospan^® (suspension for injection 7mg/mL (2mg+5mg/mL) of betamethasone) were performed in urine samples taken from patients with rheumatoid arthritis or ankylosing spondylitis for 28days after systemic intramuscular administration in routine clinical practice in an open-comparative prospective cohort study. The maximum betamethasone concentration was reached at day 4 of the follow-up; in some cases, β-phase of elimination of the drug was appeared at day 14 or at day 21 of the follow-up. The deferred β-phase elimination was likely a consequence of the physiological characteristics of the patients or of the influence of non-steroidal agents. The half-life of betamethasone was 8.5days. The elimination rate constant was 2.49h-1; the mean clearance was 4.72L/d. The recommended frequency of the drug administration to its complete elimination was estimated up to 48days. Mann-Whitney test showed no significant differences in pharmacokinetic characteristics between male and female subjects. The prolonged elimination phase was observed in patients with deviations in their body mass index, continual treatment by diclofenac and nimesulide or, possibly, after consuming an alcohol. The study was recorded in Clinical Trials open source with identifier NCT03119454.

Autoantibodies to villin occur frequently in IPEX, a severe immune dysregulation, syndrome caused by mutation of FOXP3

Intractable diarrhea is a major symptom of immune dysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX) syndrome and associated with autoantibodies against enterocytes. Although autoimmune enteropathy (AIE)-related 75 kDa antigen (AIE-75) is a prominent autoantigen involved in the enteropathy associated with IPEX syndrome, some patients with this syndrome demonstrated autoantibody recognizing a 95 kDa protein rather than AIE-75 in the small intestine. We, herewith, identified villin, an actin-binding protein, as the 95 kDa antigen. Four of five sera from patients with IPEX syndrome reacted with a fusion protein of glutathione-S-transferase and full length villin (GST-villin), whereas only three of 98 control sera weakly reacted with GST-villin. Anti-AIE-75 antibody was detected in all five IPEX sera but not in normal or control disease sera. We conclude that both AIE-75 and villin appear to be brush border autoantigens in IPEX syndrome and could be used for the diagnosis of AIE in patients with presumptive IPEX syndrome.

Clinical and molecular aspects of autoimmune enteropathy and immune dysregulation, polyendocrinopathy autoimmune enteropathy X-linked syndrome

PURPOSE OF REVIEW

Autoimmune enteropathy (AIE) is a distinct cause of severe and persistent inflammatory diarrhea in children. Recent research data allowed us to gain a first insight in the pathogenesis of AIE. On the basis of this data, we will discuss new aspects of AIE emphasizing new diagnostic and therapeutic possibilities.

RECENT FINDINGS

With the discovery of disease-causing mutations in the FOXP3 gene in patients with AIE, a dramatic advance in the understanding of AIE was made. Subsequent studies indicated that FOXP3 is a key transcription factor indispensable for regulatory functions of T cells pointing to a critical role of regulatory T-cell homeostasis in the development of AIE. Abnormal FOXP3 expression results in defective regulatory functions of T cells, which in turn cause a systemic T-cell-mediated autoaggressive disorder, now called immune dysregulation, polyendocrinopathy autoimmune enteropathy X-linked syndrome. Upon systematic review, we describe different phenotypes of immune dysregulation polyendocrinopathy autoimmune enteropathy X-linked syndrome, as well as immune dysregulation polyendocrinopathy autoimmune enteropathy X-linked-like forms of AIE, which are FOXP3 independent. No genotype-phenotype correlation could be established so far.

SUMMARY

On the basis of the profound immune dysregulation in AIE, new, most often T-cell-oriented treatment strategies were developed. The recent molecular advances in the understanding of AIE give a clear rational for the use of immunosuppression (combining steroids and tacrolimus or rapamycine) to stabilize AIE patients or to perform bone marrow transplantation in those who do not respond to immunomodulation.

Immune dysregulation in primary immunodeficiency disorders

The past several years have brought an increased awareness of the prevalence of autoimmunity and immune dysregulation among patients who have primary immunodeficiency disorders (PIDD). The recent clinical and molecular definition of PIDD, in which the primary defect is in the immunoregulatory compartment of the immune system, has offered insight into the basic mechanisms of immune tolerance, which has provided new targets and new techniques to study immune tolerance in PIDD. Many of these studies have focused on the presence and function of regulatory T (T(REG)) cells in PIDD, particularly since the discovery of murine and human syndromes associated with T(REG) deficiency. This article focuses on the current state of knowledge regarding the role of T(REG) in various PIDD that have clinical features indicative of dysregulated immunity.

IPEX as a result of mutations in FOXP3

Immunodysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX) syndrome is a rare disorder caused by mutations in the FOXP3 gene that result in the defective development of CD4+CD25+ regulatory T cells which constitute an important T cell subset involved in immune homeostasis and protection against autoimmunity. Their deficiency is the hallmark of IPEX and leads to severe autoimmune phenomena including autoimmune enteropathy, dermatitis, thyroiditis, and type 1 diabetes, frequently resulting in death within the first 2 years of life. Apart from its clinical implications, IPEX illustrates the importance of immunoregulatory cells such as CD4+CD25+ regulatory T cells.

A potential screening tool for IPEX syndrome

IPEX syndrome is a rare, inherited condition characterized by immune dysfunction, polyendocrinopathy, enteropathy, and X-linked recessive inheritance. Patients typically present in infancy with severe diarrhea and failure to thrive. Most children die by 1 year of age without therapy. The diagnosis is established by genetic analysis, which often takes several weeks to complete and can sometimes delay crucial immunosuppressive treatment. We attempted to develop a screening tool that allows rapid identification of patients with IPEX syndrome using immunocytochemical staining of FOXP3+ cells in bowel biopsies. We found that 2 patients with classic IPEX syndrome due to protein-truncating mutations in FOXP3 had markedly decreased staining of FOXP3+ T cells in the lamina propria and lymphoid aggregates. One patient with a mild, late-onset presentation and a missense mutation in FOXP3 had intact staining of FOXP3+ cells. This screening test provides a valuable tool for diagnosing IPEX syndrome in extremely ill patients who may not tolerate a delay in therapeutic intervention.

Regulatory T cells in human autoimmune diseases

In the most simplistic terms, immune tolerance can be envisioned as a balance with autoreactive cells that arise naturally in all individuals on one side and regulatory mechanisms designed to counter those autoreactive processes on the other. A tilt of the balance toward the autoreactive side, either by increasing the number or function of autoreactive cells or by diminishing regulatory mechanisms, is manifested as autoimmunity. In contrast, tilting of the balance toward increased regulation could conceivably cause immunodeficiency. Regulatory T cells (T(REG)), and particularly the naturally arising CD4(+)CD25(+) subset of T(REG) cells, provide a substantial component of the autoimmune counterbalance. The identification of forkhead box P3 (FOXP3) as a critical determinant of CD4(+)CD25(+) T(REG) development and function has provided new opportunities and generated expanded interest in studying the delicate balance between autoimmunity and regulatory mechanisms in human autoimmune diseases. Identification of both human and mouse syndromes in which FOXP3 is mutated, and consequently CD4(+)CD25(+) T(REG) cells are absent, has led to a rapid accumulation of knowledge regarding T(REG) development and function over the past 5 years. The recent development of antibody reagents to specifically identify CD4(+)CD25(+) T(REG) cells by their FOXP3 expression has provided new tools to identify these elusive cells and investigate their role in human disease. This review will focus on the current state of knowledge regarding the role of T(REG) in human autoimmune diseases and on specific human immunodeficiencies that provide interesting models of autoimmunity.

Immunodeficiencies with Autoimmune Consequences

Far from being mutually exclusive, immunodeficiency and autoimmunity may occur simultaneously. During the last years, analysis of Autoimmune Polyendocrinopathy--Candidiasis--Ectodermal Dystrophy (APECED) and Immunodysregulation--Polyendocrinopathy--Enteropathy--X-linked (IPEX), two rare monogenic forms of immunodeficiency associated with autoimmunity, has led to the identification of Auto Immune Regulator (AIRE) and Forkhead Box P3 (FOXP3), essential transcriptional regulators, involved in central tolerance and peripheral immune homeostasis, respectively. Characterization of the molecular and cellular mechanisms involved in APECED, and recognition that AIRE expression is sustained by effective thymopoiesis, has recently allowed to define that the autoimmunity of Omenn syndrome, a combined immunodeficiency due to defects of V(D)J recombination, also results from defective expression of AIRE. The implications of identification of the basis of autoimmunity in these rare forms of immunodeficiency have important implications for a better understanding of more common autoimmune disorders, and for development of novel therapeutic approaches.

Molecular defects in T- and B-cell primary immunodeficiency diseases

More than 120 inherited primary immunodeficiency diseases have been discovered in the past five decades, and the precise genetic defect in many of these diseases has now been identified. Increasing understanding of these molecular defects has considerably influenced both basic and translational research, and this has extended to many branches of medicine. Recent advances in both diagnosis and therapeutic modalities have allowed these defects to be identified earlier and to be more precisely defined, and they have also resulted in more promising long-term outcomes. The prospect of gene therapy continues to be included in the armamentarium of treatment considerations, because these conditions could be among the first to benefit from gene-therapy trials in humans.

Immune dysregulation, polyendocrinopathy, enteropathy, and X-linked inheritance (IPEX), a syndrome of systemic autoimmunity caused by mutations of FOXP3, a critical regulator of T-cell homeostasis

Immune dysregulation, polyendocrinopathy, enteropathy, and X-linked inheritance (IPEX) is one of a group of clinical syndromes that present with multisystem autoimmune disease suggesting a phenotype of immune dysregulation. Clinically, IPEX manifests most commonly with diarrhea, insulin-dependent diabetes mellitus, thyroid disorders, and eczema. FOXP3, the gene responsible for IPEX, maps to chromosome Xp11.23-Xq13.3 and encodes a putative DNA-binding protein of the forkhead family. Recent data indicate that FOXP3 is expressed primarily in the CD4+CD25+ regulatory T-cell subset, where it may function as a transcriptional repressor and key modulator of regulatory T-cell fate and function. This review describes the clinical features of IPEX and the structure, function, and known mutations of FOXP3 that provide important insights into its role in maintenance of immune homeostasis.

Immune dysregulation, polyendocrinopathy, enteropathy, X-linked syndrome: a model of immune dysregulation

PURPOSE OF REVIEW

Immune dysregulation, polyendocrinopathy, enteropathy, X-linked syndrome is a fatal syndrome of overwhelming autoimmunity. Recent identification of FOXP3 as the causative gene and realization that this same gene defect occurs in the mutant mouse Scurfy has yielded new insights and hopes of unraveling the mechanism of autoimmunity in this and possibly other diseases. In this review, we describe the clinical features of immune dysregulation, polyendocrinopathy, enteropathy, X-linked syndrome/Scurfy and compare this phenotype with similar syndromes caused by other single gene mutations. We examine therapeutic options to treat the syndrome, study its immunologic basis, and investigate the structure and function of the FOXP3 protein.

RECENT FINDINGS

The Scurfy mutant mouse has a characteristic phenotype that causes death by approximately 3 weeks of age. It is known that the effector cells in the Scurfy mouse are CD4+ T cells and that a population of normal T cells can control the overwhelming autoimmunity that they induce. Recent data have demonstrated that this process requires antigenic stimulation and that the degree to which the immune system responds is inversely proportional to the level of FOXP3 protein (Forkhead box P3) expression in peripheral T cells. Suppression of immune activation by FOXP3 may occur due to its ability to bind to DNA through a putative forkhead DNA-binding motif and to repress transcriptional activation from certain promoters in T cells.

SUMMARY

Because of the dramatic phenotype and rapidity of onset, immune dysregulation, polyendocrinopathy, enteropathy, X-linked syndrome and Scurfy provide a powerful model in which to study mechanisms of T cell regulation. A more complete understanding of this syndrome will provide important insights into mechanisms of immune suppression, tolerance, and autoimmunity.

Clinical and molecular features of the immunodysregulation, polyendocrinopathy, enteropathy, X linked (IPEX) syndrome

Immunodysregulation, polyendocrinopathy, enteropathy, X linked (IPEX, OMIM 304790) is a rare, recessive disorder resulting in aggressive autoimmunity and early death. Mutations in FOXP3 have been identified in 13 of 14 patients tested. Research in the mouse model, scurfy, suggests that autoimmunity may stem from a lack of working regulatory T cells. We review published reports regarding the genetics, clinical features, immunology, pathology, and treatment of IPEX. We also report three new patients who were treated with long term immunosuppression, followed by bone marrow transplantation in two. IPEX can be differentiated from other genetic immune disorders by its genetics, clinical presentation, characteristic pattern of pathology, and, except for high IgE, absence of substantial laboratory evidence of immunodeficiency. While chronic treatment with immunosuppressive drugs may provide temporary benefit for some patients, it does not cause complete remission. Remission has been observed with bone marrow transplantation despite incomplete engraftment, but the long term outcome is uncertain.

IPEX is a unique X-linked syndrome characterized by immune dysfunction, polyendocrinopathy, enteropathy, and a variety of autoimmune phenomena

The rare syndrome known as IPEX (OMIM: 304930) is characterized by immune-dysfunction, polyendocrinopathy, enteropathy, and X-linked inheritance. The gene responsible for IPEX maps to Xp11.23-q13.3, a region of the X chromosome that also harbors the Wiskott-Aldrich syndrome gene ( WASP ). IPEX syndrome results from mutations of a unique DNA binding protein gene, FOXP3. Mutations invariably impair the seemingly essential forkhead domain of the protein, which is uniquely located in the carboxyl terminus, affecting protein function. In this review, we describe the identification of IPEX as a unique X-linked syndrome, the clinical features of IPEX, mutations of the immune-specific FOXP3 DNA binding protein, and bone marrow transplantation as a potential cure for the syndrome, which is usually lethal within the first year of life in affected males.

Neonatal diabetes mellitus, enteropathy, thrombocytopenia, and endocrinopathy: Further evidence for an X-linked lethal syndrome

We describe an unusual family with a fatal genetic syndrome of neonatal diabetes mellitus (DM), enteropathy, endocrinopathy, and severe infections with variable thrombocytopenia. All affected individuals are male; X-linked inheritance is likely. The most common clinical features are neonatal DM, inanition, and enteropathy; a variety of other autoimmune phenomena are less frequent. Clinical variability within and among families is common, including lack of one or more cardinal features. The syndrome is usually fatal, but survival is sometimes possible with immunosuppressive therapy. Clinical variability and frequent new mutations may contribute to poor recognition and underreporting of similar cases.

Identification of an autoimmune enteropathy-related 75-kilodalton antigen

BACKGROUND & AIMS

We have previously reported a 75-kilodalton autoantigen specific to X-linked autoimmune enteropathy (AIE) associated with tubulonephropathy. The aim of this study was to identify the autoantigen.

METHODS

Complementary DNA (cDNA) clones were isolated by immunoscreening a human duodenal cDNA-expression library with serum from a patient with AIE.

RESULTS

cDNA encoding the 75-kilodalton antigen (AIE-75) was identified. The composite nucleotide sequence of the cDNA for AIE-75 was 2214 base pairs long and encoded 552 amino acids. The genomic sequence of AIE-75 was found in Sequence DataBank, which consisted of 21 exons and was located on the chromosome 11p14.3. Recombinant AIE-75 specifically reacted with sera from 3 of 4 unrelated patients with AIE but not with 58 control sera. AIE-75 was predominantly distributed in the epithelial cells of the luminal surface and the upper half of the crypts of the intestine and in the proximal renal tubulus. Similarity searches revealed that the AIE-75 cDNA sequence was an authentic form of several colon cancer-related cDNAs of unknown function. The deduced amino acid sequence contained 3 conserved PSD-95/Dlg/ZO-1 (PDZ) domains.

CONCLUSIONS

AIE-75 is a PDZ domain-containing protein expressed in the differentiated epithelial cells of the intestine and kidney and may be involved in protein-protein interaction. The identification of the autoantigen may prove useful in the approach to the pathogenesis of this poorly understood disease.

A 75-kD autoantigen recognized by sera from patients with X-linked autoimmune enteropathy associated with nephropathy

Autoimmune enteropathy (AIE) is a rare disorder characterized by intractable diarrhoea and antienterocyte autoantibody. In this study, we detected a 75-kD autoantigen which distributed through the whole intestine and the kidney, as assessed by Western blot analysis using sera from two unrelated cases of AIE associated with nephropathy. Our results suggest that the detection of the autoantibody against the 75-kD antigen has a diagnostic value in AIE and that the autoimmune reaction against the 75-kD antigen may be implicated in the development of intestinal and renal tissue damage in this rare disorder.