Case Report: Disseminated Talaromyces marneffei Infection in a Patient With Chronic Mucocutaneous Candidiasis and a Novel STAT1 Gain-of-Function Mutation.

Chronic mucocutaneous candidiasis (CMC) is a disorder of recurrent or persistent chronic noninvasive symptomatic infections of the skin, nails and mucous membranes. This disorder is primarily caused by Candida albicans. Many factors, including primary immunodeficiencies, can make a host more susceptible to CMC. Signal transducer and activator of transcription 1 (STAT1) gain-of-function (GOF) mutations are the most common genetic etiologies of CMC. We describe a case of CMC with disseminated Talaromyces marneffei infection caused by a new pathogenic Y287N mutation at amino acid 287 in the coiled-coiled domain of STAT1, which was identified using whole-exome sequencing. Position 287 might be a hot spot for missense mutations because several amino acid substitutions were found there. Flow cytometry suggested that the Y287N mutation might reduce the expression of IL-17 of Th17 cells in peripheral blood mononuclear cells stimulated by phorbol myristate acetate and ionomycin. The STAT1 Y287N GOF mutation may be the direct cause of recurrent cutaneous and mucosal candidiasis, including the T. marneffei infection in this patient.

Functional analysis of two STAT1 gain-of-function mutations in two Iranian families with autosomal dominant chronic mucocutaneous candidiasis.

Candidiasis is characterized by susceptibility to recurrent or persistent infections caused by Candida spp., typically Candida albicans, of cutaneous and mucosal surfaces. In this report, function and frequency of Th17 cells as well as genetics of patients susceptible to mucocutaneous candidiasis were studied. For patients, T-cell proliferation tests in response to Candida antigen, Th17 cell proportions, and STAT1 phosphorylation were evaluated through flow cytometry. Expression of IL17A, IL17F and IL22 genes were measured by real-time quantitative PCR. At the same time, whole exome sequencing was performed for all patients. We identified two heterozygous substitutions, one: c.821G > A (p. R274Q) was found in a multiplex family with three individuals affected, the second one: c.812A > C (p. Q271P) was found in a sporadic case. Both mutations are located in the coiled-coil domain (CCD) of STAT1. The frequency of Th17 cells, IL17A, IL17F, and IL22 gene expression in patients' peripheral blood mononuclear cells (PBMCs), and T-cell proliferation to Candida antigens were significantly reduced in the patients as compared to healthy controls. An increased STAT1 phosphorylation was observed in patients' PBMCs upon interferon (IFN)-γ stimulation as compared to healthy controls. We report two different but neighboring heterozygous mutations, located in exon 10 of the STAT1 gene, in four Iranian patients with CMC, one of whom also had hypothyroidism. These mutations were associated with impaired T cell proliferation to Candida antigen, low Th17 cell proportions, and increased STAT1 phosphorylation upon IFN-γ. We suggest that interfering with STAT1 phosphorylation might be a promising way for potential therapeutic measurements for such patients.

Complete clinical remission of invasive Candida infection with CARD9 deficiency after G-CSF treatment.

Caspase-associated recruitment domain-containing protein 9 (CARD9) deficiency is an autosomal-recessive primary immunodeficiency characterized by susceptibility to recurrent Candida infections, and its diagnosis and treatment is challenging. The present study aims to investigate the genetic characteristic and treatment strategy of a Chinese pediatric patient with CARD9 deficiency. In the present study, whole-exome sequencing (WES) was performed to screen the causal variants in a Chinese pediatric patient who exhibited an invasive Candida infection in the abdominal cavity and central nervous system. After the disease-causing gene being confirmed, the patient was treated with a combination of G-CSF and antifungal agents. DNA sequencing revealed a homozygous insertion mutation (c.819-820insG) in exon 6 of the CARD9 gene, which led to downstream amino acids conversion on codon 274 (p.D274fsX60). Th17 cell populations and cytokine levels showed decreased levels. The treatment regimen successfully resolved the patient's symptoms, and he remained symptom-free after more than 1 year of follow-up. This study described an invasive Candida infection in a pediatric patient and WES identified an insertion variant of the CARD9 gene. A combination of G-CSF and antifungal agents was highly effective in treating the invasive fungal infection accompanied by CARD9-induced immunodeficiency.

Molecular mechanism of azoles resistant Candida albicans in a patient with chronic mucocutaneous candidiasis.

BACKGROUND: More and more azole-resistant strains emerged through the development of acquired resistance and an epidemiological shift towards inherently less susceptible species. The mechanisms of azoles resistance of Candida albicans is very complicated. In this study, we aim to investigate the mechanism of azole-resistant C. albicans isolated from the oral cavity of a patient with chronic mucocutaneous candidiasis (CMC). CASE PRESENTATION: CMC diagnosis was given based on clinical manifestations, laboratory test findings and gene sequencing technique. Minimum inhibitory concentration (MIC) of the fungal isolate, obtained from oral cavity termed as CA-R, was obtained by in vitro anti-fungal drugs susceptibility test. To further investigate the resistant mechanisms, we verified the mutations of drug target genes (i.e. ERG11 and ERG3) by Sanger sequencing, and verified the over-expression of ERG11 and drug efflux genes (i.e. CDR1 and CDR2) by RT-PCR. A heterozygous mutation of c.1162A > G resulting in p.K388E was detected in STAT1 of the patient. The expression of CDR1 and CDR2 in CA-R was 4.28-fold and 5.25-fold higher than that of type strain SC5314, respectively. CONCLUSIONS: Up-regulation of CDR1 and CDR2 was mainly responsible for the resistance of CA-R. For CMC or other immunodeficiency patients, drug resistance monitoring is necessary.

Recurrent fungal infections in a Chinese patient with CARD9 deficiency and a review of 48 cases.

Deficiency of CARD9 (caspase recruitment domain-containing protein 9) has been reported in individuals with recurrent and invasive fungal infections. We report on a patient who first had Trichosporon asahii affecting the skin then Candida albicans infections involving the digestive tract and knee joint, along with elevated serum IgE. After stimulation with C. albicans, peripheral blood mononuclear cells of this patient produced less tumour necrosis factor-α, interferon-γ and interleukin-17 than those of healthy controls. Furthermore, the serum IgE levels of this patient were positively correlated with the severity of fungal infection during the course of treatment. Sanger sequencing identified one homozygous frameshift mutation (p.D274fsX60) in CARD9. We further performed a review including 48 cases with CARD9 deficiency. According to the data published previously, CARD9-deficient patients demonstrated obviously elevated IgE in serum (median 1300 IU mL-1 ), which could distinguish them from otherwise healthy people with fungal infections (area under the curve 0·94, P < 0·001). Patients carrying the mutations Q289X and Q295X had a higher mortality rate (24% vs. 0%, P < 0·05). Patients with the mutations R18W, R35Q, R70W, G72S or Y91H in the CARD domain, and the nonsense mutation Q295X in the coiled-coil domain, seemed to be more prone to Candida infections (90% vs. 20%, P < 0·005) and central nervous system infections (60% vs. 12%, P < 0·005).

Bronchiectasis and Recurrent Respiratory Infections with a De Novo STAT1 Gain-of-Function Variant: First Case in Korea.

Bronchiectasis is a chronic disease characterized by airway infection and inflammation, leading to permanent dilation of the bronchi. Evaluation of underlying etiology is important in managing young bronchiectasis patients with recurrent infections caused by unusual pathogens. The signal transducer and activator of transcription 1 (STAT1) protein plays a key role in STAT signaling and immune system regulation. Heterozygotes for gain-of-function (GOF) alleles of the STAT1 gene usually display autosomal dominant chronic mucocutaneous candidiasis (CMC) and a wide range of clinical features, such as bronchiectasis. Here, we report on a patient with CMC and bronchiectasis with various types of infections who carried a pathogenic variant of the STAT1 gene. The 24-year-old female presented with recurrent respiratory bacterial and nontuberculous mycobacterial infections complicated by severe bronchiectasis and CMC. Whole-exome sequencing revealed a c.800C>T (p.Ala267Val) heterozygous mutation in the STAT1 gene. Further analysis by Sanger sequencing of STAT1 from the patient and her parents revealed the patient had a de novo occurrence of the variant. This is the first report of a Korean patient with a GOF pathogenic variant in STAT1. Physicians should be aware of the existence of this variant as a genetic factor associated with CMC and bronchiectasis complicated by recurrent infection.

Chronic mucocutaneous candidiasis, a case study and literature review.

Chronic mucocutaneous candidiasis (CMC) is a clinically heterogeneous disease. Some immunologic and hormonal abnormalities have been associated with CMC. The factors that predispose host to CMC infection could be autosomal or acquisitive. The disease usually occurs in childhood. Here, we reviewed the published literature on chronic mucocutaneous candidiasis and a four years old girl is presented with CMC. She had a history of recurrent thrush and otomycosis since the age of one. Candida albicans was detected in skin scraping and biopsy samples. Serum iron was low. TSH hormone level was high and T4 level was low. Giardia cysts were found in stool sample. Mucocutaneous and nail manifestations of the disease were disappeared after a period of Itraconazole therapy.

IL-22 neutralizing autoantibodies impair fungal clearance in murine oropharyngeal candidiasis model.

Protection against mucocutaneous candidiasis depends on the T helper (Th)17 pathway, as gene defects affecting its integrity result in inability to clear Candida albicans infection on body surfaces. Moreover, autoantibodies neutralizing Th17 cytokines have been related to chronic candidiasis in a rare inherited disorder called autoimmune polyendocriopathy candidiasis ectodermal dystrophy (APECED) caused by mutations in autoimmune regulator (AIRE) gene. However, the direct pathogenicity of these autoantibodies has not yet been addressed. Here we show that the level of anti-IL17A autoantibodies that develop in aged Aire-deficient mice is not sufficient for conferring susceptibility to oropharyngeal candidiasis. However, patient-derived monoclonal antibodies that cross-react with murine IL-22 increase the fungal burden on C. albicans infected mucosa. Nevertheless, the lack of macroscopically evident infectious pathology on the oral mucosa of infected mice suggests that additional susceptibility factors are needed to precipitate a clinical disease.

Chronic mucocutaneous candidiasis: what can we conclude about IL-17 antagonism?

PURPOSE: IL-17 antagonists are effective for psoriasis in clinical trials, but long-term safety is not fully characterized. Since chronic mucocutaneous candidiasis (CMC) is caused by defects in the IL-17 pathway, CMC risk data have been touted as providing reassurance about the safety of IL-17 antagonism. METHODS: We performed a literature review to identify patients with CMC and compared the prevalence of cancer in these patients to the reported 5-year prevalence. RESULTS: There was a higher prevalence of oropharyngeal (2.5% vs. 0.028%; p < .0001) and esophageal cancer (1.9% vs. 0.013%; p < .0001) in patients with CMC. There were no reports of cancer in 31 patients with CMC caused by an isolated IL-17 deficiency (IL-17F, IL-17RA, IL17RC); however, a study would need over 1000 patients to detect even a 10-fold increase in the most common malignancy of CMC patients. CONCLUSIONS: There is evidence that some forms of CMC are associated with an increase in cancer. While CMC is heterogeneous, our findings suggest that we cannot use CMC data to reassure patients on the long-term safety of IL-17 antagonists beyond the safety results from clinical trials, and perhaps caution should be taken with the development of candidiasis in patients taking these medications.

Luliconazole, a new antifungal against Candida species isolated from different sources.

OBJECTIVE: Luliconazole is an inhibitor for sterol 14-α-demethylase in fungal cells with a broad-spectrum antifungal activity against dermatophytes, Candida albicans, Malassezia species, dematiaceous and hyaline hyphomycetes. Furthermore, luliconazole has been clinically used for the treatment of pityriasis versicolor, dermatophytosis, onychomycosis, cutaneous and mucocutaneous candidiasis. In the present study, we aimed to evaluate in vitro antifungal activity of luliconazole against several strains of Candida species recovered from different clinical materials. MATERIALS AND METHODS: In the present study, 104 strains of Candida species including, 34 isolates from vaginitis, 23 isolates from AIDS patients with vaginal candidiasis, 24 isolates from neutropenic patients and 24 isolates from tracheal tubes, were examined for susceptibility tests. A serial dilution of luliconazole (4-0.008µg/mL) was tested against different strains of Candida species recovered from different sources. RESULTS: The minimum inhibitory concentration (MIC) range and MIC90 of vaginal isolates (HIV-) were 1-0.063 and 1µg/mL. Furthermore, the most of strains (50%) had a MIC of 0.5µg/mL. The MIC ranges were similar (2-0.016µg/mL) for both vaginal (HIV+) and neutropenic patients isolates, whereas, MIC90 for them were 0.5 and 1µg/mL, respectively. All tracheal tubes strains were inhibited at the range of 2-0.008µg/mL with MIC90=1µg/mL. Totally, the lowest MIC50 (MIC=0.015µg/mL), MIC90 (MIC=1µg/mL) and MICGM (MIC=0.05µg/mL) are correlated to C. glabrata, a non-albicans species. CONCLUSION: It is concluded that, luliconazole could be an alternative anti-Candida agent, however, in vivo studies must be confirmed usefulness of drug for clinical usage.

Oral Administration of Human Polyvalent IgG by Mouthwash as an Adjunctive Treatment of Chronic Oral Candidiasis.

Candida albicans is a commensal fungus that can cause disease ranging in severity from moderate to severe mucosal infections to more serious life-threating disseminated infections in severely immunocompromised hosts. Chronic mucocutaneous candidiasis (CMC) occurs in patients with mutations in genes affecting IL-17-mediated immunity, such as STAT3, AIRE, RORC, CARD9, IL12B, and IL12RB1, or gain of function (GOF) mutations in STAT1. New strategies for the treatment of candidiasis are needed because of the increased burden of infections and the emergence of drug-resistant strains. In this study, we investigated an aspect of the role of antibodies in the control of C. albicans infection. We tested in vitro the effects of C. albicans opsonization with commercial human polyvalent intravenous IgG (IV IgG) on NADPH oxidase activity and killing of the fungi by blood leukocytes from 11 healthy donors and found a significant enhancement in both phenomena that was improved by IV IgG opsonization. Then, we hypothesized that the opsonization of Candida in vivo could help its elimination by mucosal phagocytes in human patients with mucocutaneous candidiasis. We tested a novel adjunctive treatment for oral candidiasis in humans based on topical treatment with IV IgG. For this purpose, we choose two pediatric patients with well-characterized primary immunodeficiencies who are susceptible to CMC. Two 8-year-old female patients with an autosomal recessive mutation in the IL12RB1 gene (P1, with oral candidiasis) and a GOF mutation in STAT1 (P2, with severe CMC persistent since the age of 8 months and resistant to pharmacological treatments) were treated with IV IgG administered daily three times a day as a mouthwash over the course of 2 weeks. The treatment with the IV IgG mouthwash reduced C. albicans mouth infection by 98 and 70% in P1 and P2, respectively, after 13 days, and complete fungal clearance was observed after complementary nystatin and caspofungin treatments, respectively. Therefore, treatment of oral candidiasis with human polyvalent IgG administered as a mouthwash helps eliminate mucosal infection in humans, circumventing drug resistance, and opening its potential use in patients with primary or transient immunodeficiency.

A gain-of-function mutation of STAT1: A novel genetic factor contributing to chronic mucocutaneous candidiasis.

Heterozygous gain-of-function (GOF) mutations in the signal transducer and activator of transcription 1 (STAT1) have increasingly been identified as a genetic cause of autosomal-dominant (AD) chronic mucocutaneous candidiasis (CMC). In this article, we describe a 33-year-old man who experienced chronic refractory candidiasis, recurrent otitis media, and pneumonia resulting in bronchiectasis, severe oral and esophageal candidiases with strictures associated with hypothyroidism and immune hemolytic anemia. His son also suffered from persistent candidiasis, chronic diarrhea, poor weight gain, and pneumonia that resulted in his demise because of sepsis. The immunological workup showed that an inverse CD4/CD8 ratio and serum immunoglobulins were all within normal ranges. The laboratory data revealed failure in response to Candida lymphocyte transformation test. In addition, by Sanger sequencing method, we found a heterozygous mutation, Thr385Met (T385M), located in the DNA-binding domain of STAT1, which was previously shown to be GOF. These findings illustrate the broad and variable clinical phenotype of heterozygous STAT1 GOF mutations. However, more clinical information and phenotype-genotype studies are required to define the clinical phenotype caused by AD STAT1 GOF.

Autosomal dominant gain of function STAT1 mutation and severe bronchiectasis.

BACKGROUND: In a substantial number of patients with non-cystic fibrosis (CF) bronchiectasis an etiology cannot be found. Various complex immunodeficiency syndromes account for a significant portion of these patients but the mechanism elucidating the predisposition for suppurative lung disease often remains unknown. OBJECTIVE: To investigate the cause and mechanism predisposing a patient to severe bronchiectasis. METHODS: A patient presenting with severe non-CF bronchiectasis was investigated. Whole exome analysis (WES) was performed and complemented by extensive immunophenotyping. RESULTS: The genetic analysis revealed an autosomal dominant gain-of-function mutation (AD- GOF) in the signal transducer and activator of transcription 1 (STAT1) in the patient. STAT1 phosphorylation studies showed increased phosphorylation of STAT1 after stimulation with interferon γ (IFN-γ). Immunophenotyping showed normal counts of CD4 and CD8 T cells, B and NK cells, but a reduction of all memory B cells especially class switched memory B cells. Minor changes in the CD8 T cell subpopulations were seen. CONCLUSIONS: Early use of WES in the investigation of non-CF bronchiectasis was highly advantageous. The degree of impairment in class-switched memory B cells may predispose patients with AD- GOF mutations in STAT1 to suppurative sinopulmonary disease.

A Case Report of Penile Infection Caused by Fluconazole- and Terbinafine-Resistant Candida albicans.

Candida albicans is the most common pathogen that causes balanoposthitis. It often causes recurrence of symptoms probably due to its antifungal resistance. A significant number of balanitis Candida albicans isolates are resistant to azole and terbinafine antifungal agents in vitro. However, balanoposthitis caused by fluconazole- and terbinafine-resistant Candida albicans has rarely been reported. Here, we describe a case of a recurrent penile infection caused by fluconazole- and terbinafine-resistant Candida albicans, as well as the treatments administered to this patient. The isolate from the patient was tested for drug susceptibility in vitro. It was sensitive to itraconazole, voriconazole, clotrimazole and amphotericin B, but not to terbinafine and fluconazole. Thus, oral itraconazole was administrated to this patient with resistant Candida albicans penile infection. The symptoms were improved, and mycological examination result was negative. Follow-up treatment of this patient for 3 months showed no recurrence.

Autoimmune Regulator Expression in DC2.4 Cells Regulates the NF-κB Signaling and Cytokine Expression of the Toll-Like Receptor 3 Pathway.

Autoimmune regulator (Aire) mutations result in autoimmune polyendocrinopathy candidiasis ectodermal dystrophy (APECED), which manifests as multi-organ autoimmunity and chronic mucocutaneous candidiasis (CMC). Indendritic cells (DCs), pattern recognition receptors (PRR), such as Toll-like receptors (TLRs), are closely involved in the recognition of various pathogens, activating the intercellular signaling pathway, followed by the activation of transcription factors and the expression of downstream genes, which take part in mediating the immune response and maintaining immune tolerance. In this study, we found that Aire up-regulated TLR3 expression and modulated the downstream cytokine expression and nuclear factor-κB (NF-κB) of the TLR3 signaling pathway.

Treatment options for chronic mucocutaneous candidiasis.

Autosomal dominant chronic mucocutaneous candidiasis (AD-CMC) is a rare and severe primary immunodeficiency that is characterized by mucocutaneous fungal infection, autoimmunity, cerebral aneurysms, and oropharyngeal and esophageal cancer. Recently, it was discovered that STAT1 mutations are responsible for AD-CMC. These mutations lead to the inability of STAT1 to be dephosphorylated, resulting in hyperphosphorylation, increased binding to the DNA, and gain of function (GOF) effects on STAT1 signaling. Furthermore, a characteristic feature of AD-CMC patients is deficiency in the T-helper 17 (Th17) responses, which is believed to be the immunological cause of the mucocutaneous fungal infection. No targeted treatment other than lifelong antifungal prophylaxis exists for AD-CMC. However, the discovery of the genetic and immunological defects makes it now possible to explore new treatment strategies. This review will discuss immunomodulatory treatment options that can be explored in patients with STAT1 GOF mutations.