Increased levels of Candida albicans mannan-specific T-cell-derived antigen binding molecules in patients with invasive candidiasis

The Role of T Helper 17 (Th17) and Regulatory T Cells (Treg) in the Pathogenesis of Vulvovaginal Candidiasis among HIV-Infected Women

Background. The study sought to describe relationships between 20 cytokines and chemokines (IL-1β, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, IL-10, IL-12, IL-13, IL-17, G-CSF, GM-CSF, IFN-γ, MCP-1, MIP-1β, TNF-α, TGF-β1, TGF-β2, and TGF-β3) and the presence of vulvovaginal candidiasis (VVC) in women, stratified by HIV status. Methods. Plasma and genital samples were obtained from 51 clinic attendees in KwaZulu-Natal between June 2011 and December 2011. Cytokine and chemokine concentrations were measured by Luminex® multiplex immunoassays. Multiple comparisons of means of cytokine/chemokine levels displaying significant differences in univariate analyses across the study groups were performed using post hoc Bonferroni pairwise tests considering a type I error rate of 0.05. A discriminant analysis (DA) was carried out to identify linear combinations of variates that would maximally discriminate group memberships. Results. Of the 51 participants, 16/26 HIV-infected and 15/25 HIV-uninfected women were diagnosed with VVC. DA identified 2 variables (MIP-1β and TGF-β3) in plasma (Box’s M (5.49), $p$ (0.57) > α (0.001); Wilks’ lambda = 0.116, $p<0.0001$ ) and 1 variable (IL-13) in vaginal secretions (Box’s M (2.063), $p$ (0.37) > α (0.001); Wilks’ lambda = .677, $p<0.0001$ ) as able to discriminate the HIV + VVC + group, whilst TGF-β1 in plasma discriminated the HIV + VVC − group. Mean concentrations of genital IL-6, IL-8, IL-10, IL-17, and TGF-β3 were significantly higher in HIV infected women coinfected with VVC. Conclusions. In HIV-infected women, VVC might be explained by a decline of Th17 cells, hence a decrease of Th17/Treg ratio.

The pattern recognition receptors expressed on neutrophils and the associated cytokine profile from different aged patients with Candida-related denture stomatitis

This study evaluated the expression of pattern recognition receptors (PRRs) and activation factors associated with salivary and blood neutrophils from different aged patients diagnosed with Candida-related denture stomatitis (DS). Expression of neutrophil PRRs was determined by flow cytometry and immunofluorescence, and the levels of selected cytokines that influence immune activation were determined by ELISA. The salivary (but not the serum derived) neutrophils of individuals with DS were found to have an increased expression of CD69 regardless of the age of the patient compared to patients without DS. However, these salivary neutrophils had a lower expression of CD66b and CD64. Expression of TLR2 was lower on the salivary- and serum-derived neutrophils from elderly individuals compared to the neutrophils of younger subjects, regardless of whether the individual had DS. Salivary interleukin (IL)-4 was elevated in both of the elderly subject groups (with or without DS). Only elderly DS patients were observed to have increased serum IL-4 levels and reduced salivary IL-12 levels. Younger DS patients showed an increase in salivary IL-10 levels, and both the saliva and the serum levels of IFN-γ were increased in all of the younger subjects. Our data demonstrated that changes in both the oral immune cells and the protein components could be associated with DS. Furthermore, changes in the blood-derived factors were more associated with age than DS status.

Activation pattern of neutrophils from blood of elderly individuals with Candida-related denture stomatitis

We have identified impaired neutrophils in elderly individuals which could be involved with Candida-related denture stomatitis (DS), an oral infection predominantly caused by Candida albicans, affecting especially elderly individuals using dental prosthesis. However, specific mechanisms performed by neutrophil contributing to the susceptibility of the elderly to DS are not fully understood. This study evaluated activation features of blood neutrophils from elderly and young individuals with DS. Blood neutrophils cultured with C. albicans from elderly subjects secreted decreased levels of CXCL8. However, C. albicans challenged-neutrophils from DS patients produced high IL-4 and IL-10, and low GM-CSF levels, regardless of age. Additional elastase activity of neutrophils from both elderly groups was detected after incubation with C. albicans, but only neutrophils from elderly DS demonstrated high myeloperoxidase activity. Therefore, DS patients have affected neutrophils, and the advance of age intensifies these damages. In summary, individuals with Candida-related denture stomatitis presented variation in the neutrophil phenotype and activation. Such alterations were more intense in neutrophils from infected elderly individuals.

Design and use of Candida scores at the intensive care unit

Invasive Candida infections are recognised as a cause of increased morbidity and mortality in intensive care patients, particularly those with recent extensive gastroabdominal surgery. Due to the difficulties of diagnosis, several authors have analysed risk factors suggestive of invasive candidiasis to identify patients at highest risk. Such patients may be potential candidates for preemptive antifungal therapy before becoming seriously ill. The extent of body site colonisation due to Candida species was recognised to be related with consequent invasive disease. The quantification of the colonisation was expressed as the Candida colonisation index. Based on the evaluation of independent risk factors predictive of invasive Candida infections, clinically relevant scores were evaluated in the last decade. Particularly, the Candida score that combines the clinical risk factors preceding surgery, total parenteral nutrition and severe sepsis with Candida multi-site colonisation can be considered a useful bedside scoring system to discern patients with mere Candida colonisation from patients with the risk of invasive candidiasis in non-neutropaenic critically ill patient population.

Individualized decreasing-dose maintenance fluconazole regimen for recurrent vulvovaginal candidiasis (ReCiDiF trial)

OBJECTIVE

Although many women with recurrent vulvovaginal candidiasis initially benefit from prophylactic intermittent treatment with antimycotics, most of them experience relapse after cessation of therapy, and often they return to the pretreatment recurrence rate. The purpose of this study was to demonstrate the efficacy and safety of an individualized, degressive, prophylactic regimen in 136 women with recurrent vulvovaginal candidiasis.

STUDY DESIGN

After an induction dose of 600 mg fluconazole during the first week, 117 women started maintenance therapy: 200 mg fluconazole weekly for 2 months, followed by 200 mg biweekly for 4 months, and 200 mg monthly for 6 months, according to their individual response to therapy. All women were tested for recurrences monthly with wet mount microscopy and vaginal culture during the first 6 months and bimonthly during the next 6 months. Patients were allowed to move on to the next level of maintenance therapy only if they were symptom free and microscopy and culture negative.

RESULTS

Of the women who were cured successfully after the induction phase, 101 women (90%) were disease-free after 6 months of maintenance therapy with this degressive regimen, and 80 women (77%) were disease-free after 1 year. The weekly incidence of the first clinical relapse was 0.5% during any period of the maintenance phase, and the rate of all new relapses, which included evidence of mycologic or microscopic colonization, was 1% per week. Women who experienced several relapses (poor responders) had experienced more relapses before entering the study compared with the optimal responders (odds ratio, 4.9; 95% CI,1.8-13.7; P = .002), experienced the disease for a longer period of time (6.5 vs 3.7 years; P = .06), and harbored significantly more Candida non-albicans during maintenance therapy (P = .001). No serious side-effects were noted.

CONCLUSION

Individualized, degressive, prophylactic maintenance therapy with oral fluconazole is an efficient treatment regimen to prevent clinical relapses in women with recurrent vulvovaginal candidiasis.

Functional group/guild modelling of inter-specific pathogen interactions: a potential tool for predicting the consequences of co-infection

Although co-infection is the norm in most human and animal populations, clinicians currently have no practical tool to assist them in choosing the best treatment strategy for such patients. Given the vast range of potential pathogens which may co-infect the host, obtaining such a practical tool may seem an intractable problem. In ecology the joint concepts of functional groups and guilds have been used to conceptually simplify complex ecosystems, in order to understand how their component parts interact and may be manipulated. Here we propose a mechanism by which to apply these concepts to pathogen co-infection systems. Further, we describe how these groups could be incorporated into a mathematical modelling framework which, after validation, could be used as a clinical tool to predict the outcome of any particular combination of pathogens co-infecting a host.

Cell and antibody mediated immunity induced by vaccination with novel Candida dubliniensis mannan immunogenic conjugate

Antigen-specific humoral response, as well as the induction of cellular immunity generated by Candida dubliniensis mannan-human serum albumin (HSA) conjugate, a novel proposed immunogenic structure for subcellular vaccine, were evaluated in rabbits. Mannan-HSA conjugate-induced specific IgG and IgA increased significantly after boosters (IgG: P<0.001 and IgA: P<0.01). Mannan-HSA conjugate up-regulation of cell-surface expression of B-lymphocyte and granulocyte activation antigens CD25 and CD11b indicated the effective activation. Immunogenic effect of conjugate on T lymphocytes was demonstrated via inductive increase of CD4+ T lymphocyte subset and CD4+/CD8+ ratio and via induction of T(H)1 cytokines. Immunogenic effectiveness of mannan-HSA conjugate at a dose of 0.25 mg of mannan antigenic moiety overcame that of the mannan alone and of yeast whole cells, thus promising further application in Candida vaccine development.

Candida infections in the intensive care unit: epidemiology, risk factors and therapeutic strategies

This article reviews the epidemiology, predisposing risk factors and outcome of systemic Candida spp. infections in the intensive care unit setting. Incidence of systemic Candida infections in patients requiring intensive care has increased substantially in recent years; while diagnosis of serious Candida infection may be difficult, the clinical conditions which predispose patients to these infections are now better understood and effective antifungal therapies are becoming increasingly available. Severe fungal infections are generally associated with poor outcomes in these patients. Patients at highest risk for Candida infection may be potential candidates for early, presumptive therapy. In this article we review antifungal treatment, including the use of polyenes, azoles and echinocandines, and the role of prophylaxis.