Oral Candida colonization and candidiasis in patients with psoriasis

Difference in immune responses to Candida albicans in two inbred strains of male rats

OBJECTIVE

To investigate the influence of strain differences in immune response on the pathogenesis of oral candidiasis in Dark Agouti (DA) and Albino Oxford (AO) inbred strains of rats.

DESIGN

Seventy male 8-weeks old DA and AO rats were inoculated with Candida albicans to induce three different experimental models of oral candidiasis, one immunocompetent and two immunocompromised models. The animals were sacrificed after 16 days from the beginning of the experiment followed by collecting the samples of the tongue dorsum and blood for histopathological (PAS and H&E staining), immunohistochemical, qRT-PCR, and oxidative stress analyses.

RESULTS

Histopathological and immunohistochemical analyses revealed lower levels of epithelial colonization, epithelial damage, and inflammatory infiltration in DA compared to AO strain of rats. DA rats had fewer CD45, CD68, and CD3 positive cells but more HIS 48 positive cells than AO rats. The expressions of IL-1β, TNFα, IFN-γ, IL-10 and TGF-β1 were consistently higher in DA strain across all experimental models. However, the expressions of IL-4 and IL-17 differed inconsistently between DA and AO strain in various experimental models. Strain differences were observed in levels of prooxidative hydrogen peroxide and lipid peroxidation, with higher levels presented in AO rats compared to DA rats, while antioxidative parameters presented little yet inconsistent difference between strains.

CONCLUSION

DA strain of rats consistently presented lower susceptibility to oral infection with C. albicans compared to AO strain with robust Th1/Th17 immune response indicating the importance of the genetic background on the development of oral candidiasis.

Oral Candida and psoriasis: Is there association? A systematic review and trial sequential analysis

To assess (i) the prevalence of oral colonization by Candida spp. in patients with psoriasis and (ii) the prevalence of oral lesions associated with Candida spp. in patients with psoriasis and identify the risk factors for oral lesions. A systematic review was conducted in accordance with PRISMA criteria. The PROSPERO registration code is CRD42019127178. PubMed, Scopus and Web of Science were used as search engines. Meta-analyses and trial sequential analyses were performed. Among the 5805 retrieved records, nine articles were included. Among 530 psoriatic patients, 255 patients had an oral Candida spp. colonisation with an odds ratio (OR) = 3.44 (95% CI:2.38-5.00). Among 490 psoriatic patients, 43 patients developed oral Candida spp. lesions with an OR = 5.31 (95% CI:1.04-27.23). Among the patients without the main predisposing factors for infections, psoriatic patients had a higher OR (3.48, 95% CI: 2.0-6.0) for Candida spp. colonization, but not for Candida spp. infection, when compared with healthy controls (p-value > 0.05). Meta-analysis showed a higher risk of Candida spp. colonisation in patients with psoriasis. Patients who received immunosuppressive therapies were also at higher risk of developing oral lesions. Further studies are needed to understand these associations.

Candida Infection Associated with Anti-IL-17 Medication: A Systematic Analysis and Review of the Literature

Anti-interleukin (IL)-17 agents have shown excellent therapeutic efficacy in patients with psoriasis and are expected to be expanded to other chronic inflammatory diseases. However, patients receiving anti-IL-17 agents are at an increased risk of developing Candida infection, with some agents reported to increase the incidence in a dose-dependent manner. Interleukin-17 is secreted by the Th17 subset of CD4+ lymphocytes, CD8+ T cells, and innate cells, including natural killer T cells, lymphoid tissue inducer cells, innate lymphoid cells, and γδ-T cells, and plays an important role in antifungal defense. Genetic defects in the IL-17-signaling pathway in both humans and animal models render susceptibility to candidiasis caused by Candida albicans. The purpose of this narrative review is to evaluate the literature on the role of IL-17 in protection against candidiasis, the prevalence of candidiasis in anti-IL-17 agent use, and to offer clinical recommendations on the diagnosis and management of anti-IL-17 medication-associated candidiasis.

A Practical Guide to the Management of Oral Candidiasis in Patients with Plaque Psoriasis Receiving Treatments That Target Interleukin-17

Plaque psoriasis is an immune-mediated inflammatory skin disease associated with the dysregulation of cytokines, especially those involved in the interleukin (IL)-23/IL-17 pathways. In recent years, there has been growing interest in developing biologic therapies that target these pathways. However, inhibition of the cytokines of the IL-23/IL-17 pathways may increase patients' risk of developing fungal infections, particularly oral candidiasis. Therefore, it is important that dermatology practitioners can effectively diagnose and treat oral candidiasis. In this review, we examine the role of the IL-23/IL-17 pathways in antifungal host defense, and provide a practical guide to the diagnosis and treatment of oral candidiasis in patients with psoriasis. Overall, while treatment with anti-IL-17 medications leads to an increased incidence of oral candidiasis in patients with psoriasis, these cases are typically mild or moderate in severity and can be managed with standard antifungal therapy without discontinuing treatment for psoriasis. If applicable, patients with psoriasis should also be advised to practice good oral hygiene and manage or control co-existing diabetes, and should be provided with information on smoking cessation to prevent oral candidiasis.

Prevalence of Candida species in Psoriasis

BACKGROUND

Psoriasis patients are more frequently colonised with Candida species. The correlation between fungal colonisation and clinical severity is unclear, but may exacerbate psoriasis and the impact of antipsoriatic therapies on the prevalence of Candida is unknown.

OBJECTIVES

To examine the prevalence of C species in psoriasis patients compared to an age- and sex-matched control population, we investigated the influence of Candida colonisation on disease severity, immune cell activation and the interplay on psoriatic treatments.

METHODS

The prevalence of C species was examined in 265 psoriasis patients and 200 control subjects by swabs and stool samples for fungal cultures. Peripheral mononuclear blood cells (PBMCs) were collected from 20 fungal colonised and 24 uncolonised patients and stimulated. The expression of interferon (IFN)-γ, IL-17A, IL-22 and tumour necrosis factor (TNF)-α from stimulated PBMCs was measured by quantitative real-time polymerase chain reaction (qPCR).

RESULTS

A significantly higher prevalence for Candida was detected in psoriatic patients (p ≤ .001) compared to the control subjects; most abundant in stool samples, showing Candida albicans. Older participants (≥51 years) were more frequent colonised, and no correlation with gender, disease severity or systemic treatments like IL-17 inhibitors was found.

CONCLUSIONS

Although Candida colonisation is significantly more common in patients with psoriasis, it does not influence the psoriatic disease or cytokine response. Our study showed that Candida colonisation is particularly more frequent in patients with psoriasis ≥51 years of age. Therefore, especially this group should be screened for symptoms of candidiasis during treatment with IL-17 inhibitors.

Interplay between Humoral and CLA+ T Cell Response against Candida albicans in Psoriasis

Candida albicans (CA) infections have been associated with psoriasis onset or disease flares. However, the integrated immune response against this fungus is still poorly characterized in psoriasis. We studied specific immunoglobulins in plasma and the CA response in cocultures of circulating memory CD45RA^- cutaneous lymphocyte antigen (CLA)^+/- T cell with autologous epidermal cells from plaque and guttate psoriasis patients (cohort 1, n = 52), and also healthy individuals (n = 17). A complete proteomic profile was also evaluated in plaque psoriasis patients (cohort 2, n = 114) regarding their anti-CA IgA levels. Increased anti-CA IgA and IgG levels are present in the plasma from plaque but not guttate psoriasis compared to healthy controls. CA cellular response is confined to CLA⁺ T cells and is primarily Th17. The levels of anti-CA IgA are directly associated with CLA⁺ Th17 response in plaque psoriasis. Proteomic analysis revealed distinct profiles in psoriasis patients with high anti-CA IgA. C-C motif chemokine ligand 18, chitinase-3-like protein 1 and azurocidin were significantly elevated in the plasma from plaque psoriasis patients with high anti-CA levels and severe disease. Our results indicate a mechanism by which Candida albicans exposure can trigger a clinically relevant IL-17 response in psoriasis. Assessing anti-CA IgA levels may be useful in order to evaluate chronic psoriasis patients.

Immunity to commensal skin fungi promotes psoriasiform skin inflammation

Under steady-state conditions, the immune system is poised to sense and respond to the microbiota. As such, immunity to the microbiota, including T cell responses, is expected to precede any inflammatory trigger. How this pool of preformed microbiota-specific T cells contributes to tissue pathologies remains unclear. Here, using an experimental model of psoriasis, we show that recall responses to commensal skin fungi can significantly aggravate tissue inflammation. Enhanced pathology caused by fungi preexposure depends on Th17 responses and neutrophil extracellular traps and recapitulates features of the transcriptional landscape of human lesional psoriatic skin. Together, our results propose that recall responses directed to skin fungi can directly promote skin inflammation and that exploration of tissue inflammation should be assessed in the context of recall responses to the microbiota.

Secukinumab in moderate-to-severe plaque psoriasis: a multi-center, retrospective, real-life study up to 52 weeks observation

OBJECTIVES

To evaluate efficacy and safety of the anti-IL-17 drug secukinumab in a real-life large cohort of patients with moderate-to-severe plaque psoriasis in Central Italy.

METHODS

Multicenter, retrospective study with an observation period of up to 52 weeks. Efficacy was assessed by Psoriasis Area and Severity Index (PASI) score; clinical and laboratory examinations were performed at baseline and at weeks 4, 12, 24, 36, and 52.

RESULTS

A 90% and a 100% PASI score reduction (PASI90 and PASI100) were reported in 67.5% and 55% of patients at week 12, respectively. A rapid improvement of skin lesions was observed particularly in young patients and in patients naïve to biologics: at week 4, the achievement of PASI90 and PASI100 was higher in younger patients (odds ratio [OR] 0.95, and 0.95; p = 0.003, and 0.005, respectively); PASI90 was achieved by 42.0% of patients naïve to biologics and by 17.0% of patients with prior exposure to biologics (PBT) (OR 0.24; p = 0.001); and PASI100 was reached by 25.5% of naïve patients and 9.8% of PBT (OR 0.28; p = 0.015).The drug was well tolerated.

CONCLUSION

Secukinumab was effective in this real-life analysis, with rapid clinical improvement and long-term maintenance of results.

Prevalence and Possible Role of Candida Species in Patients with Psoriasis: A Systematic Review and Meta-Analysis

Although fungal colonization is implicated in the pathogenesis of psoriasis, its prevalence remains unclear. The aim of this systematic review and meta-analysis was to provide an overview on the prevalence of Candida species in patients with psoriasis. We searched databases (MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, and http://clinicaltrials.gov) to identify studies involving subjects of any age with an established diagnosis of psoriasis and healthy controls, who were tested for carriage of Candida spp. on the skin or mucosal membranes (or saliva and stool), or presented with clinical candidiasis with microbiologically confirmed etiology. We identified nine cross-sectional studies including a total of 1038 subjects with psoriasis (psoriatics) and 669 controls. We found Candida species detection rates for psoriatics were significantly higher than those in the controls, especially in the oral mucosa milieux. These results suggest psoriasis may be one of the systemic diseases that predispose to oral Candida spp. carriage and infection.

Oral Candida colonization and plaque type psoriasis: Is there any relationship?

AIM

The potential role of superantigens derived from microbial agents could be considered in the pathogenesis of psoriasis, but the association between Candida albicans and psoriasis severity is still controversial. The present study was designed to compare the prevalence of oral candidiasis in a group of psoriatic patients and healthy patients, and its correlation with psoriasis severity.

METHODS

Seventy psoriatic patients with no history of systemic treatment and 70 closely-matched control patients underwent oral examination. Scraping of oral mucosa to detect Candida species was done using a sterile cytobrush.

RESULTS

Candida was detected in the oral cavity of 20% of patients with psoriasis and 2.8% of control cases (P = .002), but none had clinical features of oral candidiasis. Candida albicans was the only species isolated from the oral cavity of both groups. No correlation was found between sex, age, phototherapy, and presence of oral candidiasis. There was a positive correlation between psoriasis severity and colony count (P < .001).

CONCLUSIONS

The prevalence of oral candidiasis is higher in psoriatic patients and is associated with disease severity. It is not exactly clear whether oral candidiasis can aggravate psoriasis or if psoriasis can predispose patients to oral candidiasis.