Recurrent, Severe Aphthous Stomatitis and Mucosal Ulcers as Primary Manifestations of a Novel STAT1 Gain-of-Function Mutation

Recurrent Enteritis and Intestinal Obstruction in a Patient with Chronic Mucocutaneous Candidiasis due to STAT1 Gain-of-Function Mutation

We presented a case of chronic mucocutaneous candidiasis (CMC) due to STAT1 GOF mutation with recurrent enteritis and intestinal obstruction. A 33-year-old woman complained of recurrent oral erosion and finger (toe) nails damage for over 30 years. Candida albicans were cultured from the oral mucosa and nails. Sanger sequencing revealed a gain-of-function mutation in STAT1 (c.A1159 G, p.T387A). Since the age of 37, she developed recurrent enteritis and intestinal obstruction. Laboratory examinations revealed an increased pSTAT1 protein expression and a decreased proportion of Th17 cells in peripheral blood lymphocyte (PBMC), with a high expression of pSTAT1 and scarce expression of IL17A observed in intestinal immunohistochemistry. Intestinal obstruction had not previously been reported as the main clinical manifestation in STAT1 GOF patients. We speculated that the low levels of IL17A impaired the intestinal barrier, which might lead to gastrointestinal disorders in this patient. This case expanded the clinical phenotype of heterozygous STAT1 GOF patients.

Human oral mucosa and oral microbiome interactions following supragingival plaque reconstitution in healthy volunteers: a diet-controlled balanced design proof-of-concept model to investigate oral pathologies

Changes in the oral microbiome may contribute to oral pathologies, especially in patients undergoing cancer therapy. Interactions between oral microbiome and oral mucosa may exacerbate inflammation. We determined whether probiotic-controlled plaque formation could impact proximal oral mucosa gene expression profiles in healthy volunteers. A 3-weeks balanced sample collection design from healthy volunteers (HVs) was implemented. At Week-1 plaques samples and labial mucosa brush biopsies were obtained from HVs in the morning (N = 4) and/or in the afternoon (N = 4), and groups were flipped at Week-3. A fruit yogurt and tea diet were given 2-4hrs before sample collection. mRNA gene expression analysis was completed using RNA-Seq and DESeq2. Bacterial taxa relative abundance was determined by 16S HOMINGS. Bacterial diversity changes and metabolic pathway enrichment were determined using PRIMERv7 and LEfSe programs. Alpha- and beta-diversities did not differ morning (AM) vs. afternoon (PM). The most affected KEGG pathway was Toll-like receptor signaling in oral mucosa. Eighteen human genes and nine bacterial genes were differentially expressed in plaque samples. Increased activity for 'caries-free' health-associated calcifying Corynebacterium matruchotii and reduced activity for Aggregatibacter aphrophilus, an opportunistic pathogen, were observed. Microbial diversity was not altered after 8 hours plaque formation in healthy individuals as opposed to gene expression.

Leveraging Systems Immunology to Optimize Diagnosis and Treatment of Inborn Errors of Immunity

Inborn errors of immunity (IEI) are monogenic disorders that can cause diverse symptoms, including recurrent infections, autoimmunity and malignancy. While many factors have contributed, the increased availability of next-generation sequencing has been central in the remarkable increase in identification of novel monogenic IEI over the past years. Throughout this phase of disease discovery, it has also become evident that a given gene variant does not always yield a consistent phenotype, while variants in seemingly disparate genes can lead to similar clinical presentations. Thus, it is increasingly clear that the clinical phenotype of an IEI patient is not defined by genetics alone, but is also impacted by a myriad of factors. Accordingly, we need methods to amplify our current diagnostic algorithms to better understand mechanisms underlying the variability in our patients and to optimize treatment. In this review, we will explore how systems immunology can contribute to optimizing both diagnosis and treatment of IEI patients by focusing on identifying and quantifying key dysregulated pathways. To improve mechanistic understanding in IEI we must deeply evaluate our rare IEI patients using multimodal strategies, allowing both the quantification of altered immune cell subsets and their functional evaluation. By studying representative controls and patients, we can identify causative pathways underlying immune cell dysfunction and move towards functional diagnosis. Attaining this deeper understanding of IEI will require a stepwise strategy. First, we need to broadly apply these methods to IEI patients to identify patterns of dysfunction. Next, using multimodal data analysis, we can identify key dysregulated pathways. Then, we must develop a core group of simple, effective functional tests that target those pathways to increase efficiency of initial diagnostic investigations, provide evidence for therapeutic selection and contribute to the mechanistic evaluation of genetic results. This core group of simple, effective functional tests, targeting key pathways, can then be equitably provided to our rare patients. Systems biology is thus poised to reframe IEI diagnosis and therapy, fostering research today that will provide streamlined diagnosis and treatment choices for our rare and complex patients in the future, as well as providing a better understanding of basic immunology.

Case Report: Eosinophilic Esophagitis in a Patient With a Novel STAT1 Gain-of-Function Pathogenic Variant

Background

STAT1 gain-of-function (GOF) is a primary immune dysregulatory disorder marked by wide infectious predisposition (most notably chronic mucocutaneous Candidiasis), autoimmunity, vascular disease and malignant predisposition. While atopic features have been described in some STAT1 GOF patients, they are not considered a predominant feature of the disease. Additionally, while eosinophilic gastrointestinal infiltration has been reported in some cases, this has always been described in the context of pre-existing oropharyngeal and/or esophageal Candidiasis.

Clinical cases

Herein, we report 3 members of a multi-generational family diagnosed with STAT1 GOF caused by a novel mutation in the N-terminal domain, c.194A>C (p.D65A). The proband presented initially with a long-standing history of treatment-refractory eosinophilic esophagitis (EoE) without preceding gastrointestinal tract fungal infections, and her mother was diagnosed with esophagitis as well.

Conclusion

EoE has been previously associated with alterations to STAT6 and STAT3 signaling pathways. The current report expands the possible association between JAK/STAT-related disorders and EoE, suggesting that EoE could be a primary disease manifestation of STAT1 GOF, even in the absence of oropharyngeal and/or esophageal Candidiasis.

Transcriptome sequencing and metabolome analysis reveal the mechanism of Shuanghua Baihe Tablet in the treatment of oral mucositis

Oral mucositis (OM) caused by cancer therapy is the most common adverse reaction in the radiotherapy of head and neck tumors. In severe cases, it can lead to the interruption of treatment, which affects the control of the disease and the quality of life. Shuanghua Baihe Tablet (SBT) is a traditional Chinese medicine (TCM) formula, which is administerd to treat OM in China. It has been clinically effective for more than 30 years, but the underlying mechanism is not completely understood. With the development of multiple omics, it is possible to explore the mechanism of Chinese herbal compound prescriptions. Based on transcriptomics and metabolomics, we explored the underlying mechanism of SBT in the treatment of OM. An OM model of rats was established by 5-FU induction, and SBT was orally administered at dosages of 0.75 and 3 g·kg^-1·d^-1. In order to search for SBT targets and related metabolites, the dysregulated genes and metabolites were detected by transcriptomics and metabolomics. Immune related indicators such as interleukin-17 (IL-17) and tumor necrosis factor-α (TNF-α) were detected by ELISA. Treg cell disorders was analyzed by flow cytometry. Our results showed that SBT significantly alleviated the symptoms of OM rats and the inflammatory infiltration of ulcer tissues. After SBT administration, inflammatory related metabolic pathways including linoleic acid metabolism, valine, leucine and isoleucine biosynthesis were significantly altered. Furthermore, the production of proinflammatory factors like IL-17 and TNF-α, were also dramatically reduced after SBT administration. Besides, the infiltration degree of Treg cells in the spleen of OM modeling rats was significantly improved by SBT administration, thus maintaining the immune balance of the body. The current study demonstrates that SBT regulates inoleic acid metabolism, glycerophospholipid metabolism and amino acid metabolism, and inhibits IL-17/TNF signal transduction to restore Treg and Th17 cell homeostasis in OM rats, thereby alleviating chemotherapy-induced OM.

Genetic and immunologic findings in children with recurrent aphthous stomatitis with systemic inflammation

BACKGROUND

Recurrent aphthous stomatitis with systemic signs of inflammation can be encountered in inflammatory bowel disease, Behçet's disease (BD), Systemic Lupus Erythematosus (SLE). In addition, it has been proposed that cases with very early onset in childhood can be underpinned by rare monogenic defects of immunity, which may require targeted treatments. Thus, subjects with early onset recurrent aphthous stomatitis receiving a clinical diagnosis of BD-like or SLE-like disease may deserve a further diagnostic workout, including immunologic and genetic investigations.

OBJECTIVE

To investigate how an immunologic, genetic and transcriptomics assessment of interferon inflammation may improve diagnosis and care in children with recurrent aphthous stomatitis with systemic inflammation.

METHODS

Subjects referred to the pediatric rheumatologist for recurrent aphthous stomatitis associated with signs of systemic inflammation from January 2015 to January 2020 were enrolled in the study and underwent analysis of peripheral lymphocyte subsets, sequencing of a 17-genes panel and measure of interferon score.

RESULTS

We enrolled 15 subjects (12 females, median age at disease onset 4 years). The clinical diagnosis was BD in 8, incomplete BD in 5, BD/SLE overlap in 1, SLE in 1. Pathogenic genetic variants were detected in 3 patients, respectively 2 STAT1 gain of function variants in two patients classified as BD/SLE overlap and SLE, and 1 TNFAIP3 mutation (A20 haploinsufficiency) in patients with BD. Moreover 2 likely pathogenic variants were identified in DNASE1L3 and PTPN22, both in patients with incomplete BD. Interferon score was high in the two patients with STAT1 GOF mutations, in the patient with TNFAIP3 mutation, and in 3 genetic-negative subjects. In two patients, the treatment was modified based on genetic results.

CONCLUSIONS

Although recurrent aphthous stomatitis associated with systemic inflammation may lead to a clinical diagnosis of BD or SLE, subjects with early disease onset in childhood deserve genetic investigation for rare monogenic disorders. A wider genetic panel may help disclosing the genetic background in the subset of children with increased interferon score, who tested negative in this study.

Inborn errors of STAT1 immunity

Signal transducer and activator of transcription 1 (STAT1) is a latent cytoplasmic transcription factor that is activated by multiple stimuli, including type I, II, and III interferons and interleukin-27. Inborn errors of human STAT1 immunity underlie 4 distinct disorders: autosomal recessive (AR) complete STAT1 deficiency, AR partial STAT1 deficiency, autosomal dominant (AD) STAT1 deficiency, and AD STAT1 gain-of-function. Each disease presents distinct clinical manifestations, excluding the difference in two AR STAT1 deficiencies, which are mainly explained by severity. This observation reflects the multiple and complex roles of STAT1 and how STAT1-mediated signaling is finely tuned in host immune systems.

Immune Dysfunction in Mendelian Disorders of POLA1 Deficiency

POLA1 encodes the catalytic unit of DNA polymerase α, which together with the Primase complex launches the DNA replication process. While complete deficiency of this essential gene is presumed to be lethal, at least two conditions due to partial POLA1 deficiency have been described. The first genetic syndrome to be mapped to POLA1 was X-linked reticulate pigmentary disorder (XLPDR, MIM #301220), a rare syndrome characterized by skin hyperpigmentation, sterile multiorgan inflammation, recurrent infections, and distinct facial features. XLPDR has been shown to be accompanied by profound activation of type I interferon signaling, but unlike other interferonopathies, it is not associated with autoantibodies or classical autoimmunity. Rather, it is accompanied by marked Natural Killer (NK) cell dysfunction, which may explain the recurrent infections seen in this syndrome. To date, all XLPDR cases are caused by the same recurrent intronic mutation, which results in gene missplicing. Several hypomorphic mutations in POLA1, distinct from the XLPDR intronic mutation, have been recently reported and these mutations associate with a separate condition, van Esch-O'Driscoll syndrome (VEODS, MIM #301030). This condition results in growth retardation, microcephaly, hypogonadism, and in some cases, overlapping immunological features to those seen in XLPDR. This review summarizes our current understanding of the clinical manifestations of POLA1 gene mutations with an emphasis on its immunological consequences, as well as recent advances in understanding of its pathophysiologic basis and potential therapeutic options.