The Catestatin-Derived Peptides Are New Actors to Fight the Development of Oral Candidosis

Resistance to antifungal therapy of Candida albicans and non-albicans Candida strains, frequently associated with oral candidosis, is on the rise. In this context, host-defense peptides have emerged as new promising candidates to overcome antifungal resistance. Thus, the aim of this study was to assess the effectiveness against Candida species of different Catestatin-derived peptides, as well as the combined effect with serum albumin. Among Catestatin-derived peptides, the most active against sensitive and resistant strains of C. albicans, C. tropicalis and C. glabrata was the D-isomer of Cateslytin (D-bCtl) whereas the efficiency of the L-isomer (L-bCtl) significantly decreases against C. glabrata strains. Images obtained by transmission electron microscopy clearly demonstrated fungal membrane lysis and the leakage of the intracellular material induced by the L-bCtl and D-bCtl peptides. The possible synergistic effect of albumin on Catestatin-derived peptides activity was investigated too. Our finding showed that bovine serum albumin (BSA) when combined with the L- isomer of Catestatin (L-bCts) had a synergistic effect against Candida albicans especially at low concentrations of BSA; however, no synergistic effect was detected when BSA interacted with L-bCtl, suggesting the importance of the C-terminal end of L-bCts (GPGLQL) for the interaction with BSA. In this context in vitro D-bCtl, as well as the combination of BSA with L-bCts are potential candidates for the development of new antifungal drugs for the treatment of oral candidosis due to Candida and non-Candida albicans, without detrimental side effects.

Understanding the Protective Role of IL-17 During Oropharyngeal Candidiasis

Oropharyngeal candidiasis is an opportunistic mucosal infection caused predominantly by Candida albicans. While healthy individuals are protected, susceptibility is associated with immunodeficiency. In particular, patients with defects related to T helper-17 (Th17) cells and interleukin (IL)-17 signaling are highly susceptible to mucocutaneous forms of candidiasis. Since mice are naïve to Candida albicans, induction of oropharyngeal candidiasis enables a thorough understanding of IL-17 and its related immune components during acute infection. Here we describe a murine model of oropharyngeal candidiasis. This protocol allows for translatable and reproducible infection with results that can be obtained between 2 and 5 days following infection.

Activation of EphA2-EGFR signaling in oral epithelial cells by Candida albicans virulence factors

During oropharyngeal candidiasis (OPC), Candida albicans invades and damages oral epithelial cells, which respond by producing proinflammatory mediators that recruit phagocytes to foci of infection. The ephrin type-A receptor 2 (EphA2) detects β-glucan and plays a central role in stimulating epithelial cells to release proinflammatory mediators during OPC. The epidermal growth factor receptor (EGFR) also interacts with C. albicans and is known to be activated by the Als3 adhesin/invasin and the candidalysin pore-forming toxin. Here, we investigated the interactions among EphA2, EGFR, Als3 and candidalysin during OPC. We found that EGFR and EphA2 constitutively associate with each other as part of a heteromeric physical complex and are mutually dependent for C. albicans-induced activation. Als3-mediated endocytosis of a C. albicans hypha leads to the formation of an endocytic vacuole where candidalysin accumulates at high concentration. Thus, Als3 potentiates targeting of candidalysin, and both Als3 and candidalysin are required for C. albicans to cause maximal damage to oral epithelial cells, sustain activation of EphA2 and EGFR, and stimulate pro-inflammatory cytokine and chemokine secretion. In the mouse model of OPC, C. albicans-induced production of CXCL1/KC and CCL20 is dependent on the presence of candidalysin and EGFR, but independent of Als3. The production of IL-1α and IL-17A also requires candidalysin but is independent of Als3 and EGFR. The production of TNFα requires Als1, Als3, and candidalysin. Collectively, these results delineate the complex interplay among host cell receptors EphA2 and EGFR and C. albicans virulence factors Als1, Als3 and candidalysin during the induction of OPC and the resulting oral inflammatory response.

Oropharyngeal candidiasis occurs when the fungus Candida albicans proliferates in the mouth to a point at which tissue damage occurs. The disease is characterized by fungal invasion of the superficial epithelium and a localized inflammatory response. Two C. albicans virulence factors contribute to the pathogenesis of OPC, Als3 which enables the organism to adhere to and invade host cells, and candidalysin which is a pore-forming toxin that damages host cells. Two epithelial cell receptors, ephrin type-A receptor 2 (EphA2) and the epidermal growth factor receptor (EGFR) are activated by C. albicans. Here, we show that EphA2 and EGFR form part of complex wherein these co-receptors are required to activate each other. Als3 enhances the host cell targeting of candidalysin by stimulating epithelial cell endocytosis of C. albicans, leading to the formation of an endocytic vacuole in which candidalysin accumulates. Thus, Als3 and candidalysin synergize to damage epithelial cells, activate EphA2 and EGFR, and stimulate the production of inflammatory mediators. In the mouse model of OPC, candidalysin elicits of a subset of the oral inflammatory response molecular repertoire. Of the cytokines and chemokines induced by this toxin, some require the activation of EGFR while others are induced independently of EGFR. Collectively, this work provides a deeper understanding of the interactions among C. albicans virulence factors, host cell receptors and immune responses during OPC.

Candida albicans Interaction with Oral Epithelial Cells: Adhesion , Invasion, and Damage Assays

Microbial interactions with epithelial barriers are important steps preceding disease. Infections with Candida albicans are no exception. This opportunistic fungus, commonly harmlessly residing in close proximity to human epithelia, can shift to a more pathogenic form, can invade tissues, and cause disease. Pathogenesis, in C. albicans as well as in many other microorganisms, is characterized by three important steps: adhesion to-, invasion into-, and damage of host cells. In this book chapter, we describe three well-established protocols that allow us to differentially stain C. albicans cells adhering to and invading into host cells, therefore allowing quantifications of such processes. We also describe a common host cell cytotoxicity assay that employs a commercial kit, adapted to C. albicans.

Signaling through IL-17C/IL-17RE is dispensable for immunity to systemic, oral and cutaneous candidiasis

Candida albicans is a commensal fungal microbe of the human orogastrointestinal tract and skin. C. albicans causes multiple forms of disease in immunocompromised patients, including oral, vaginal, dermal and disseminated candidiasis. The cytokine IL-17 (IL-17A) and its receptor subunits, IL-17RA and IL-17RC, are required for protection to most forms of candidiasis. The importance of the IL-17R pathway has been observed not only in knockout mouse models, but also in humans with rare genetic mutations that impact generation of Th17 cells or the IL-17 signaling pathway, including Hyper-IgE Syndrome (STAT3 or TYK2 mutations) or IL17RA or ACT1 gene deficiency. The IL-17 family of cytokines is a distinct subclass of cytokines with unique structural and signaling properties. IL-17A is the best-characterized member of the IL-17 family to date, but far less is known about other IL-17-related cytokines. In this study, we sought to determine the role of a related IL-17 cytokine, IL-17C, in protection against oral, dermal and disseminated forms of C. albicans infection. IL-17C signals through a heterodimeric receptor composed of the IL-17RA and IL-17RE subunits. We observed that IL-17C mRNA was induced following oral C. albicans infection. However, mice lacking IL-17C or IL-17RE cleared C. albicans infections in the oral mucosa, skin and bloodstream at rates similar to WT littermate controls. Moreover, these mice demonstrated similar gene transcription profiles and recovery kinetics as WT animals. These findings indicate that IL-17C and IL-17RE are dispensable for immunity to the forms of candidiasis evaluated, and illustrate a surprisingly limited specificity of the IL-17 family of cytokines with respect to systemic, oral and cutaneous Candida infections.

Morphologic and morphometric analysis of alternations in the oral cavity caused by Candida albicans--experimental work

INTRODUCTION

Candidiasis has become a human disease of increasing importance in the last decades. The aim of the study is to establish pathomorphological alterations caused by the blastospores of the Candida albicans as well as morphometric alterations.

MATERIAL AND METHODS

The experiment was carried out on 2.5-month-old rats, weighting 110-130 g. The study sample was divided into the animals infected by a submucous inoculation in the periodontal region and the controls. The gingival specimens were taken, preparations were done and stained by the hematoxylin-eosin and Periodic acid Schiff methods.

RESULTS

The following alterations were found out by the stereological analysis: an average volume of nuclei of the gingival epithelial cells was 111.82 microm3 (SD = 25.34) on the first day. A statistically significant increase in the volume of nuclei in the experimental group began to occur from the fourth day (202.97 microm3; SD = 31.16, p < 0.05) and the highest value of the nuclei volume was found out on the eight day of the experiment (316.83 microm3; SD = 40.15).

CONCLUSION

Blastospores of Candida albicans are pathogenic for the gingival tissue where they cause degenerative necrotic alterations of the granulomatous character and after the fourth day from the inoculation, the development of the pseudohyphae was observed. The obtained values of stereologic measurement show the acute increase in the volume of nuclei.

Elucidating role of salivary proteins in denture stomatitis using a proteomic approach

Denture stomatitis (DS) is the most common oral pathology among denture wearers, affecting over one-third of this group. DS is usually associated with C. albicans. However, unlike other oral candidiasis, most DS patients have intact host immunity. The presence of a denture alone is usually sufficient for DS. Saliva and its protein contents can theoretically predispose some denture wearers to DS and others resistant toward DS. Here we proposed for the first time to define salivary proteomic profiles of denture wearers with and without DS. SELDI-TOF/MS analysis suggests that there is a proteomic differentiation among control, localized and generalized DS. Based on initial SELDI-TOF/MS profiling, we further used reversed phase liquid chromatography, MALDI-TOF/MS, and LC-MS/MS to characterize the salivary proteins associated with DS. Nineteen proteins based on SELDI-TOF/MS profiling were found including cystatin-SN, statherin, kininogen-1, desmocollin-2, carbonic anhydrase-6, peptidyl-prolyl cis-trans isomerase A like peptides, cystatin C, and several immunoglobulin fragments. The proteomic content gives evidence of the interaction between host tissue, saliva, and candida. Further examination in larger populations of these proteins may help to gain a better understanding of DS pathological processes and improve DS treatments.

Detection of Candida by calcofluor white

OBJECTIVE

To assess the efficacy of calcofluor white (CFW) is compared to Gram stain and periodic acid-Schiff in detection of Candida in oral precancer and cancer.

STUDY DESIGN

The study group consisted of patients with precancer (n = 45), cancer (n = 45) and control group (n = 45). Presence of Candida was confirmed by culture inoculation along with a germ tube and carbohydrate fermentation test. The cytopathologic smears were analyzed by Papanicolaou-CFW and Gram staining, whereas, tissue sections were stained by periodic acid-Schiff and CFW staining.

RESULTS

Candida albicans was the predominant species identified. A highly significant association of Candida was seen more often in cancer than in precancer. Both in cytology and histopathology Candida detection by CFW was higher. In precancer it was 48.88% in smears and 40% in tissue sections, whereas, in cancer 60% in smears and 55.55% in histopathology.

CONCLUSION

Among the various diagnostic tools used in the present study, the use of CFW is seen to be a simple, effective, rapid and reliable method, both in cytopathology and histopathology.

Interventions for treating oral candidiasis for patients with cancer receiving treatment

BACKGROUND

Treatment of cancer is increasingly effective but is associated with short and long term side effects. Oral and gastrointestinal side effects, including oral candidiasis, remain a major source of illness despite the use of a variety of agents to treat them.

OBJECTIVES

To assess the effectiveness of interventions for the treatment of oral candidiasis for patients with cancer receiving chemotherapy or radiotherapy or both.

SEARCH STRATEGY

Computerised searches of Cochrane Oral Health Group and PaPaS Trials Registers (to 1 June 2010), CENTRAL via the Cochrane Library (Issue 2, 2010, 1 June 2010), MEDLINE via OVID (1 June 2010), EMBASE via OVID (1 June 2010), CINAHL via EBSCO (1 June 2010), CANCERLIT via PubMed (1 June 2010), OpenSIGLE (1 June 2010) and LILACS via Virtual Health Library (1 June 2010) were undertaken. Reference lists from relevant articles were searched and the authors of eligible trials were contacted to identify trials and obtain additional information.

SELECTION CRITERIA

All randomised controlled trials comparing agents prescribed to treat oral candidiasis in people receiving chemotherapy or radiotherapy for cancer. The outcomes were eradication of oral candidiasis, dysphagia, systemic infection, amount of analgesia, length of hospitalisation, cost and patient quality of life.

DATA COLLECTION AND ANALYSIS

Data were independently extracted, in duplicate, by two review authors. Trial authors were contacted for details of randomisation and withdrawals and a quality assessment was carried out. Risk ratios (RR) were calculated using fixed-effect models.

MAIN RESULTS

Ten trials involving 940 patients, satisfied the inclusion criteria and are included in this review. Drugs absorbed from the gastrointestinal (GI) tract were beneficial in eradication of oral candidiasis compared with drugs not absorbed from the GI tract (three trials: RR = 1.29, 95% confidence interval (CI) 1.09 to 1.52), however there was significant heterogeneity. A drug absorbed from the GI tract, ketoconazole, was more beneficial than placebo in eradicating oral candidiasis (one trial: RR = 3.61, 95% CI 1.47 to 8.88). Clotrimazole, at a higher dose of 50 mg was more effective than a lower 10 mg dose in eradicating oral candidiasis, when assessed mycologically (one trial: RR = 2.00, 95% CI 1.11 to 3.60). Only one of the ten trials was assessed as at low risk of bias.

AUTHORS' CONCLUSIONS

There is insufficient evidence to claim or refute a benefit for any antifungal agent in treating candidiasis. Further well designed, placebo-controlled trials assessing the effectiveness of old and new interventions for treating oral candidiasis are needed. Clinicians need to make a decision on whether to prevent or treat oral candidiasis in patients receiving treatment for cancer.

[Increase of saliva nitrate and nitrite level in patients with oral candidiasis]

OBJECTIVE

To observe the alterations of saliva nitrate and nitrite level in patients with oral candidiasis.

METHODS

Parotid saliva and whole saliva were collected from 33 patients and 34 healthy volunteers. Concentrations of nitrate and nitrite in saliva were determined by high-performance liquid chromatography. Follow-up observation was performed on 10 patients after treatment. The data were statistically analyzed with independent-samples t test or paired-samples t test at alpha = 0.05.

RESULTS

There was significant increase of the concentrations and secretion rate of parotid saliva nitrate in patient group as compared with controls: (49.70 +/- 0.50) vs (21.51 +/- 0.60) mg/L (t = 2.692, P = 0.009) and (27.71 +/- 0.50) vs (12.55 +/- 0.60) microg/min (t = 2.554, P = 0.013), respectively. Significantly increased concentrations and secretion rate of nitrate and nitrite [nitrate: (6.46 +/- 0.94) vs (1.11 +/- 0.70) mg/L (t = 3.792, P = 0.000); nitrite: (8.48 +/- 0.58) vs (3.39 +/- 0.53) mg/L (t = 2.888, P = 0.005); nitrate secretion rate: (10.57 +/- 0.91) vs (2.10 +/- 0.74) microg/min (t = 3.464, P= 0.001); nitrite secretion rate: (13.91 +/- 0.55) vs (6.42 +/- 0.58) microg/min (t = 2.397, P = 0.020)] were revealed in whole saliva of patients group. Significantly decreased nitrate and nitrite levels were also observed in patients after treatment, especially the changes of parotid saliva nitrate secretion rate [(37.50 +/- 0.50) vs (14.34 +/- 0.64) microg/min (t = 3.142, P = 0.012)], whole saliva nitrate [(14.29 +/- 1.01) vs (2.59 +/- 1.03) mg/L (t = 3.475, P = 0.007)] and whole saliva nitrate secretion rate [(25.97 +/- 0.93) vs (4.12 +/- 1.00) microg/min (t = 3.922, P = 0.003)].

CONCLUSION

The present study revealed the significant increase of salivary nitrate and nitrite level in patients with oral candidiasis is considered to be associated with the host defense reaction.

[Salivary glands and oral mucous membrane status in patients with chronic hepatitis]

The status of salivary glands and oral mucous membrane was investigated in 50 patients with chronic active hepatitis against the background of chronic alcoholism. The check up disclosed sialadenosis in 38% of patients and in 54% of patients - such diseases of oral mucous membrane as stomatitis, candidosis and geographic tonque. Besides there were disclosed such disturbances as big and small salivary glands secretion reduction, mixed saliva viscosity increase, increase of protein, P, K, Na and catalase content in it, glycogen hyperaccumulation in gingival tissues. The received data indicated the necessity of dispensary supervision of such patients and their treatment in stomatologist.

The role of candida in inflammatory papillary hyperplasia of the palate

The objective of this study was to investigate the expression by immunohistochemistry of the major basement membrane (BM) components (laminin, collagen type IV, fibronectin) in specimens from the palatal mucosa lesions of patients with complete dentures and diagnosis of inflammatory papillary hyperplasia of the palate (IPHP). Furthermore to evaluate the potential role of candidal infection in patients with IPHP. Biopsies of palatal mucosa were obtained from patients with IPHP, generally healthy/orally healthy patients with dentures, and healthy subjects. Immunohistochemical studies performed with specific antibodies to BM proteins. Scrapings and swaps of oral lesions from all patients and control groups were taken from the palate, and Candida species colonization was assessed with mycology tests. Immunohistochemical expression of BM components revealed thin linear staining in the BM of healthy palatal mucosa. In IPHP discontinuities or disruptions in BM were observed at the interface between epithelium and the underlying connective tissue in the areas of severe inflammatory response. Our findings suggest an interaction between the expression of BM components and Candida involvement in the development of IPHP, a disorder involving inflammatory reaction and modification of soft tissues.

Effect of a novel phyto-compound on mucosal candidiasis: further evidence from an ex vivo study

OBJECTIVE

To isolate, identify and determine the prevalence of yeasts in the oral cavity of individuals and to test the minimum inhibitory dilution (MID) of Kolorex against the yeasts isolated.

METHODS

Twenty-nine individuals of both sexes aged on average 61.3 years were evaluated at the dental clinic in order to isolate and identify yeasts from their oral cavity, with and without lesions, and to determine the MID of the commercial phyto-product Kolorex against the strains isolated. The antifungal activity of the product tested was determined by the technique of dilution on a solid medium. Monocyte chemoattractant protein 1 (MCP-1) was measured by biotinylated antibody assay by an enzyme-linked immunosorbent assay (ELISA).

RESULTS

Yeasts of the genus Candida were detected in the saliva of 45.4% of the 11 individuals with a clinically healthy mouth and in 88.2% of 17 individuals with oral lesions. In the group with oral candidiasis we isolated in tongue and lesion, respectively, for each species: C. tropicalis (5.8% and 11.7%), C. glabrata (5.8% and 5.8%) and C. parapsilosis (0% and 5.8%), in addition to C. albicans as the only species or in association with others, respectively (64.7% and 70.5%). The total clonal formation unit (CFU) (counts/mL) in the saliva showed a higher mean value in the group with oral candidiasis (158.3x10(3)) than in the control group (64.6x10(3)). Most of the 70 test strains (95.7%) were sensitive to Kolorex by presenting a MID of 1:20. Sixty percent of strains from the 70 healthy sites showed results similar to those obtained with strains from oral lesions. Different results were mainly observed among different species. Patients with oral lesions showed a significant time-course increase of the level of monocyte chemoattractant protein 1 (MCP 1) as compared to those without lesions or to healthy people in whom Candida has not been detected (P<0.05). Co-culture with Kolorex using aliquots from the same patients with oral lesions inhibited such event (P<0.05).

CONCLUSION

Although this study was focused on oral cavity candidiasis, the results indicate the possibility of a broader use of the antifungal Kolorex in the prevention and treatment of mucosal candidiasis located elsewhere.

Candida albicans HWP1 gene expression and host antibody responses in colonization and disease

In vivo expression of the developmentally regulated Candida albicans hyphal wall protein 1 (HWP1) gene was analysed in human subjects who were culture positive for C. albicans and had oral symptoms (n=40) or were asymptomatic (n=29), or had vaginal symptoms (n=40) or were asymptomatic (n=29). HWP1 mRNA was present regardless of symptoms, implicating hyphal and possibly pseudohyphal forms in mucosal carriage as well as disease. As expected, in control subjects without oral symptoms (n=10) and without vaginal symptoms (n=10) who were culture negative in oral and vaginal samples, HWP1 mRNA was not detected. However, exposure to Hwp1 in healthy culture-negative controls, as well as in oral candidiasis and asymptomatic mucosal infections, was shown by the existence of local salivary and systemic adaptive antibody responses to Hwp1. The results are consistent with a role for Hwp1 in gastrointestinal colonization as well as in mucosal symptomatic and asymptomatic infections. Overall, Hwp1 and hyphal growth forms appear to be important factors in benign and invasive interactions of C. albicans with human hosts.

Characterization of the immune status of CD8+ T cells in oral lesions of human immunodeficiency virus-infected persons with oropharyngeal Candidiasis

Oropharyngeal candidiasis (OPC) remains the most common oral infection in human immunodeficiency virus (HIV) disease. In a high percentage of HIV(+) persons with reduced CD4(+) T cells, oral lesions with Candida present at the outer epithelium have an accumulation of CD8(+) T cells at the epithelium-lamina propria interface associated with reduced expression of the mucosal cell-trafficking adhesion molecule E-cadherin. The purpose of the present study was to characterize the immune status of these CD8(+) T cells. Immunohistochemical staining for phenotypic and activation and costimulation markers was performed on frozen biopsy tissue sections from HIV(+) OPC(+) persons with accumulated CD8(+) T cells. CD8(+) T cells consisted primarily of central memory cells by virtue of positive CD45RO (memory) and CD27 (central memory) expression. However, concomitant negative expression of CD62L and CCR7 (effector memory) was suggestive of a transitioning memory phenotype within the tissue. Despite this, the cells are considered to be activated on the basis of positive expression of CD69. The CD8(+) T cells are not considered to be NK T cells or anti-HIV CD8(+) T cells because of negative or low expression of CD161 and vascular cell adhesion molecule, respectively. These results suggest that the accumulated mucosal migratory-challenged CD8(+) T cells are otherwise normal memory T cells in an activated state.

Salivary secretory leukocyte protease inhibitor and oral candidiasis in human immunodeficiency virus type 1-infected persons

Oropharyngeal candidiasis, typically caused by Candida albicans, is the most common oral disease associated with human immunodeficiency virus type 1 (HIV-1) infection. Secretory leukocyte protease inhibitor (SLPI), a 12-kDa antiprotease, suppresses the growth of C. albicans in vitro. To determine whether the mucosal protein plays a role in protecting oral tissues against fungal infection, we conducted a cross-sectional study investigating the oral and systemic health and salivary SLPI levels in 91 dentate HIV-1-infected adults receiving medical care in the southeastern United States. Participants with a self-reported history of clinical oropharyngeal candidiasis during the previous 2 years constituted the test group (n = 52), while the comparison group (n = 39) had no oropharyngeal candidiasis during that period. Data collected from medical records, oral examination, and SLPI enzyme-linked immunosorbent assay quantitation of whole saliva were analyzed by t test, analysis of variance, linear regression, and unconditional logistic regression. The test group had a significantly higher mean salivary SLPI level than the comparison group (1.9 microg/ml versus 1.1 microg/ml, P < 0.05). Linear regression modeling identified CD4 cell count and history of oropharyngeal candidiasis as key predictors of salivary SLPI and revealed a significant interaction (P < 0.05) between immunosuppression (CD4 cell count below 200 cells/ microl) and positive history of oropharyngeal candidiasis in predicting salivary SLPI level. By logistic regression modeling, a salivary SLPI level exceeding 2.1 microg/ml, low CD4 count, antiretroviral monotherapy, and smoking were key predictors of oropharyngeal candidiasis. These data support a key role for SLPI in the oral mucosal defense against C. albicans. The antimicrobial mucosal protein may serve as an indicator of previous oropharyngeal candidiasis infection among immunosuppressed persons.

In vitro analyses of tissue structure and interleukin-1β expression and production by human oral mucosa in response to Candida albicans infections

Clinical and experimental observations suggest that oral epithelial cells play a key role in host defenses against candidal infections through cytokines and chemokines. We thus attempted to determine whether oral epithelial cells convey IL-1beta as a pro-inflammatory cytokine in response to Candida albicans infections. We created engineered human oral mucosa (EHOM), put them in contact with live and heat-inactivated C. albicans (10(5) yeast/cm2), and measured the expression of IL-1beta mRNA and protein. Tissue structure and C. albicans morphology were also evaluated. Only live C. albicans modulated IL-1beta expression and secretion. IL-1beta mRNA expression significantly increased during the early stages of infection and decreased during the later stages. The modulatory effect of C. albicans on IL-1beta expression was confirmed by the fact that increased amounts of inactive IL-1beta (33 kDa) were detected early during the infection which then dropped dramatically. There was a significant and time-dependent increase in the amount of the active form of IL-1beta (17 kDa) secreted into the supernatant by epithelial cells infected with live C. albicans. Histological features revealed damage to infected tissues (separation of epithelial cells, edema, vacuolization, reduction in thickness) compared to uninfected ones. Morphological analyses showed that C. albicans changed from a blastospore to a hyphal form at later infection periods. This transformation was very pronounced at 8 and 24 h post-infection. These results provide additional evidence for the contribution of oral epithelial cells to local defenses against exogenous stimulations such as C. albicans infections.

The expression of toll-like receptor 2 and 4 mRNA in local tissues of model of oropharyngeal candidiasis in mice

To investigate the expression of Toll-like receptor (TLR) 2 and 4 mRNA in local tissues of model of oropharyngeal candidiasis in mice and to explore the potential role of TLR2 and TLR4 in earlier period of immune response, a murine model of oropharyngeal candidiasis inoculated by cotton wool balls saturated with Candida albicans was established. Mice were sacrificed at the indicated time points and the oropharyngeal tissues were excised. The expression of TLR2 and TLR4 mRNA was detected by RT-PCR. The results showed that low level of TLR2/4 mRNA could be detected in oropharyngeal tissues, but they were markedly up-regulated 6 h after inoculation, peaking after 12-24 h. Tissue TLR4 mRNA was gradually down-regulated 24-48 h, while TLR2 mRNA levels remained high up to the 72nd h. These data suggested that oropharyngeal infection of Candida albicans could result in up-regulation of TLR2/4 mRNA expression in local tissues, which might play important roles in earlier period of immune response.

Decreased excretion of antimicrobial proteins and peptides in saliva of patients with oral candidiasis

BACKGROUND

Antimicrobial peptides in saliva appear to play a crucial role in the regulation of oral Candida growth, and study on antimicrobial excretion in saliva and oral candidiasis appears useful for the analysis of pathophysiology of oral candidiasis.

METHODS

To clarify the role of saliva in the regulation of oral Candida growth, the levels of antimicrobial proteins and peptides and their excretion rates were examined in saliva obtained from 50 patients with oral candidiasis and 35 healthy individuals.

RESULTS

The inhibitory activities of patients' saliva against Candida adhesion with HeLa cells and against Candida growth (radiolabeled glucose incorporation) were lower than those of saliva from the healthy controls. The salivary levels of lactoferrin (Lf; 11 +/- 9 microg/ml), secretory immunoglobulin A (sIgA; 160 +/- 37 microg/ml), beta-defensin 1 (375 +/- 37 ng/ml), and beta-defensin 2 (412 +/- 51 ng/ml) in the patients were largely lower than those in the control group (33 +/- 14 microg/ml, 204 +/- 51 microg/ml, 452 +/- 89 ng/ml, and 530 +/- 142 ng/ml, respectively), although the transferrin (Tf) and secretory component (SC) levels were almost same in both groups, and alpha-defensin 1 was slightly increased in the patient group (660 +/- 115 ng/ml vs. 467 +/- 168 ng/ml). In addition, the excretion rates of the proteins and peptides were largely decreased in the patients (Tf: 14 +/- 2 microg/10 min vs. 34 +/- 7 microg/10 min; Lf: 18 +/- 11 microg/10 min vs. 139 +/- 43 microg/10 min; sIgA: 300 +/- 132 microg/10 min vs. 900 +/- 207 microg/10 min; SC: 112 +/- 46 microg/10 min vs. 292 +/- 64 microg/10 min; alpha-defensin 1: 1223 +/- 431 ng/10 min vs. 2044 +/- 612 ng/10 min; beta-defensin 1: 687 +/- 243 ng/10 min vs. 1985 +/- 295 ng/10 min; and beta-defensin 2: 784 +/- 299 ng/10 min vs. 2288 +/- 278 ng/10 min).

CONCLUSION

These results conclusively suggest that oral candidiasis is associated with salivary gland hypofunction and that decreases of salivary antibacterial proteins induce Candida overgrowth.

New sensitive method for the measurement of lysozyme and lactoferrin to explore mucosal innate immunity. Part II: time-resolved immunofluorometric assay used in HIV patients with oral candidiasis

The aim of this study was to explore lysozyme and lactoferrin concentrations in human immunodeficiency virus (HIV)-infected patients with oropharyngeal candidiasis (OPC). These proteins were measured by time-resolved immunofluorometric assay, validated in Part I of this study, in paired serum and salivary secretions of 30 patients. Eleven HIV-positive patients without OPC, eight HIV-positive patients with OPC and eleven HIV-negative healthy subjects were included in the study. The relative coefficient of excretion of salivary albumin was used to establish protein origin. In serum, the low lactoferrin concentrations in HIV-infected patients with and without OPC (0.610 mg/l (p < 0.05) and 0.896 mg/l (p < 0.01) vs. 1.439 mg/l in healthy subjects) were probably due to a decrease in nonspecific immunity, particularly the polymorphonuclear cells. In HIV-infected patients with OPC, the high salivary lysozyme and lactoferrin concentrations (170.94 mg/l and 66.48 mg/l vs. 23.35 mg/l and 10.20 mg/l in healthy subjects, respectively) and their mean relative coefficient of excretion of above 1 indicated a high local production of lysozyme and lactoferrin in saliva. The development of OPC in HIV-infected patients could be a consequence of inefficient lysozyme and lactoferrin concentrations and of decreased cooperation between innate and adaptative immune systems.

Nonspecific secretory immunity in HIV-infected patients with oral candidiasis

Buccal and digestive tract opportunistic infections occur frequently in patients infected by HIV. In this study, we measured lysozyme (Lz), lactoferrin (Lf), total IgA (T-IgA), and secretory IgA (S-IgA) levels to investigate nonspecific secretory immunity in HIV-infected patients with oral candidiasis. Serum, saliva, and stool samples were analyzed by time-resolved immunofluorometric assay for Lz and Lf levels and by enzyme-linked immunosorbent assay for T-IgA and S-IgA levels. Mean salivary Lf and T-IgA levels (66.50 mg/L and 0.10 g/L, respectively) and mean fecal Lf, T-IgA, and S-IgA outputs (0.87, 54.0, and 43.6 mg/d, respectively) were significantly higher in HIV-infected patients with oropharyngeal candidiasis than in HIV-infected patients without oropharyngeal candidiasis and healthy subjects. There was a modification in the molecular form rate, with a high increase in S-IgA and monomeric IgA transudation from the plasmatic compartment into salivary and digestive fluids and an increase in salivary Lf local synthesis by polymorphonuclear neutrophils. HIV infection appears to be associated with dysregulation of some of the nonspecific immune factors at the mucosal surface. Despite high saliva concentrations and high intestinal output, innate immunity was not able to stop yeast expansion in HIV-infected patients.

Evaluation of serum and saliva components in candidosis patients

The serum and saliva components of 36 chronic Candidosis patients, both male and female, ages 38-82 who attended the Department of Clinical Stomatology were studied. Total Mucous Lesion Index (TMLI) and salivary flow rate were assessed. The following parameters were evaluated: iron bound protein, unsaturated iron binding capacity, peroxidase activity, protein content, OSCN-, SCN-, IgAs, Candida and St. mutans levels and lactobacilli activity. Candidosis patients exhibited higher Candida CFU values and increased activity of the peroxidase system (p < 0.05) whereas unsaturated iron binding capacity was significantly lower as compared to healthy subjects (p < 0.05). Furthermore, TMLI and Candida CFU values were higher in diseased subjects wearing complete prosthesis as compared to those without complete prosthesis. Diseased subjects with < 1.2 ml/min salivary flow rate exhibited even greater differences with control. This subgroup exhibited a marked reduction in IgAs. The serum components assayed were iron bound protein, unsaturated iron binding capacity, IgG, IgA and IgM. Unsaturated iron binding capacity was significantly lower in the Candidosis group (p = 0.03). Subjects suffering from oral Candidosis display deficiencies in some of their saliva components, evidencing impaired oral defense capacity.

Immunohistochemical study on expression of alpha-defensin and beta-defensin-2 in human buccal epithelia with candidiasis

OBJECTIVES AND DESIGN

It has been previously reported that alpha-defensin (HNPs) and beta-defensin-2 (HBD-2) peptides with antifungal and cytotoxic activities can be detected in oral carcinomas and the saliva of patients with oral carcinomas. The present study investigated the presence of HNPs and HBD-2 in oral epithelia with candidiasis.

MATERIALS AND METHODS

Tissue sections (4 microm) were prepared from biopsy and surgically removed specimens diagnosed as oral candidiasis (n = 10). The sections were examined immunohistochemically with antibodies directed against HNPs and HBD-2.

RESULTS

Tissue sections of oral candidiasis were immunostained with antidefensin antibodies. Neutrophils in the inflamed lamina propria were positively immunostained with anti-HNPs antibody. The cytoplasm of cells in the upper spinous layer, in the lower spinous layer and in the parakeratinized layer of buccal epithelia with candidiasis was immunostained intensely with anti-HBD-2 antibody. In contrast, the expression of HBD-2 in the normal spinous layer was much weaker than that in oral candidiasis. No signals of HNPs were found in normal buccal epithelium.

CONCLUSION

Buccal specimens from individuals with oral candidiasis show greater levels of expression of both HNPs and HBD-2. There might be a dual protection manner by defensins against fungal inflammation in infected buccal epithelia locally. Generally, HBD-2 signals have been found everywhere in the buccal epithelium; however, in an infected area, the signal intensity of HBD-2 has increased. HNPs signals have not been found in the normal buccal epithelium; however, HNPs signals have increased when the infection occurred.

[Molecular pathogenesis of oral candidiasis (candidosis)]

Candida species are the most important pathogenic fungi in the oral cavity with the predominance of Candida albicans. In this review the authors summarise the most important cell-surface bound pathogenical factors such as fibrinogen, fibronectin, thrombin, collagen, laminin and vitronectin-binding proteins and extracellular virulence enzymes of Candida albicans and some microbiological aspects of oral candidiasis (candidosis). Adherence to both artificial and mucosal surfaces is mediated by hydrophobic interactions and by ligand-receptor attachment. Surface bound proteins on Candida cells bind to mucosal surface proteins. Broad spectrum antibacterial treatment liberates binding sites for Candida colonisation by means of reducing the number of bacterial normal flora in the oral cavity. Non immune humoral factors such as iron, lysosyme, hystidine-rich-polypeptides, lactoferrin, lactoperoxidase and immune globulins such as s-IgA, moreover, elements of cellular immunity, especially polymorphonuclear leucocytes contribute to preventing the establishment of Candida infection. A disbalance in these constituents may result in colonisation and biofilm production of Candida. The biofilm consist of serum proteins mainly fibrin, desquamated epithelial cells, dead leukocytes, living and multiplying candida cells, pseudohyphae and extracellular matrix excreted by candida cells. Living candida cells are deeply embedded in the biofilm, thus protected from defence mechanisms of the host. Continuous destruction of mucosal surfaces beneath the biofilm may create a portal of entry for systematic candidal infections.

Can fluconazole concentrations in saliva be used for therapeutic drug monitoring?

The saliva/plasma concentration ratio of fluconazole was investigated in 22 HIV-1-infected individuals with an oropharyngeal Candida infection to determine whether saliva fluconazole concentrations could provide useful information for therapeutic drug monitoring in this population. Steady-state paired plasma and saliva samples were obtained after approximately 1 week of treatment with 50-or 100-mg fluconazole as capsules. A significant correlation between plasma and salivary levels of fluconazole was observed. The median saliva/plasma concentration ratio was 1.3 and was independent of the ingested dose and the plasma fluconazole concentration. The prediction of fluconazole concentrations in plasma from the concentrations in saliva was, although unbiased, not precise. From these findings, the authors conclude that although stimulated salivary fluconazole concentrations are significantly correlated with plasma concentrations, it is not possible to predict plasma fluconazole levels from the salivary concentrations with adequate precision. However, saliva fluconazole concentrations have sufficient value to test for compliance and even semiquantitative prediction of plasma concentrations.

A comparison of salivary calprotectin levels in subjects with and without oral candidiasis

OBJECTIVES

The purpose of this study was to compare salivary calprotectin levels in subjects with oral candidiasis to the levels in healthy age- and sex-matched control subjects and to investigate the relationship of salivary calprotectin to intensity of oral candidal carriage and infection and to predisposing factors for candidiasis.

STUDY DESIGN

Using enzyme-linked immunosorbent assay, we measured calprotectin in unstimulated whole saliva collected from 22 subjects with oral candidiasis and in saliva collected from 22 control subjects. Calprotectin levels in the 2 groups were compared by using the Wilcoxon signed rank test. The relationships between calprotectin levels and Candida counts were assessed by using the Spearman rank correlation test. The nonparametric 1-way analysis of variance test was used to study the relationship between calprotectin levels and presence of non-albicans Candida and individual predisposing factors for candidiasis. The Kruskal-Wallis test was used to evaluate the relationship between calprotectin and predisposing factors in subjects grouped by total number of predisposing factors identified.

RESULTS

No relationship was found between calprotectin and individual or total number of predisposing factors. Higher calprotectin levels were found in subjects with candidiasis, and calprotectin concentration positively correlated with intensity of candidal infection.

CONCLUSIONS

These findings suggest that calprotectin production, or release, or both, may be increased in subjects with candidiasis.

Salivary calprotectin levels are raised in patients with oral candidiasis or Sjögren's syndrome but decreased by HIV infection

Calprotectin levels were determined in whole saliva from patients predisposed to oral candidiasis due to HIV infection or Sjögren's syndrome and from patients with candidiasis associated with various oral disorders (e.g. lichen planus, oral ulceration). Mean calprotectin levels were higher in whole saliva (2 microgram/ml) than in parotid saliva (0.3 microgram/ml). Oral candidiasis was associated with raised whole saliva calprotectin levels in all groups studied. HIV infection was associated with lower levels of salivary calprotectin, in the presence of high or low salivary Candida counts, although CD4+ lymphocyte counts did not significantly correlate with calprotectin concentrations. Calprotectin levels were elevated in saliva from Sjögren's syndrome patients with oral candidiasis, consistent with mucosal transudation of calprotectin from inflamed mucosa and limited dilution due to decreased salivary flow rates. This study indicates that oral candidiasis is associated with raised calprotectin levels secondary to mucosal inflammation, but that diminution of this candidacidal factor due to HIV infection may be a predisposing factor in the aetiology of oral candidiasis.

[Type IV collagen and C-erbB-2 expression in oral candidal leukoplakia]

OBJECTIVE

To investigate type IV collagen and C-erbB-2 expression in oral candidal leukoplakia.

METHODS

27 cases of oral candidal leukoplakia were studied by immunohistochemistry.

RESULTS

In normal and simple hyperplastic epithelia type IV collagen was noted as brown linear staining along the basement membrane. The most obvious change in the staining pattern was that the linear staining became very thin or discontinued in dysplastic epithelia. C-erbB-2 was demonstrated in 25 cases(78%). The positive staining, as a reticular pattern, was located at cell membrane, and not correlated with epithelial dysplasia.

CONCLUSION

The results indicate that type IV collagen expression changed in candidal leukoplakia with epithelial dysplasia. This kind of change may be related to basement membrane destruction. The immunohistochemically expression of C-erbB-2 has no correlation with epithelial dysplasia.

In vivo expression and localization of Candida albicans secreted aspartyl proteinases during oral candidiasis in HIV-infected patients

Isoforms of aspartyl proteinase (Sap), which are encoded by at least nine related SAP genes, have been implicated to be a major virulence factor of the opportunistic yeast Candida albicans in experimental infections. Although it is generally assumed that proteinases are important for infections, detailed information on the pathogenetic role of Saps is still lacking. The same applies to the question whether the genes and corresponding isoforms of the enzyme are expressed during oral infection. For in vivo investigations, parts of the lesional oral epithelium were collected from three HIV-infected patients with oropharyngeal candidiasis. Immunoelectron microscopy was performed (pre- and post-embedding gold labeling with silver enhancement) using an anti-Sap murine monoclonal antibody directed against the gene products Sap1-3. It was possible to demonstrate expression of Sap antigens in each of the three samples of human oral candidiasis. This suggests that at least one of the genes SAP1-3 was expressed at the time of sample collection. Furthermore, a possible role of the enzymes during the interaction of yeast cells and mucosal cells is suggested: the majority of Sap antigens is secreted by those C. albicans cells that adhere directly to the epithelial surface. Sap immunoreactivity can be detected in particular at the site of close contact between C. albicans and epithelial cells, suggesting a pathogenetic role of the Saps in host-fungal interaction. Thus, inhibition of the enzyme might prove to be an important alternative in the prevention and treatment of candidiasis.

Salivary histatins in patients with recurrent oral candidiasis

The level of salivary histatins was evaluated in 20 patients with a history of recurrent oral candidiasis and in age-, sex-matched healthy controls. Salivary pH, flow rate, total protein and histatins were compared. Results of this study indicated that salivary pH was significantly lower among patients than controls (5.9 vs. 6.3, respectively, P = 0.002). No significant difference was observed in the mean flow rate and total protein between patients and controls (0.39 ml/min/gland vs. 0.46 ml/min/gland and 112.4 mg% vs. 113.0 mg%, respectively). However, the mean salivary histatin levels were significantly higher among patients than controls, both in terms of concentration (16.8 mg% vs. 11.1 mg%, P = 0.016) as well as a ratio of total protein (15 mg/g vs. 10 mg/g, P = 0.018). These findings indicate that oral candidiasis is associated with increased levels of salivary histatin. Such a finding suggests that oral candidiasis may modulate the levels of salivary histatin.

Pharmacokinetics of itraconazole (oral solution) in two groups of human immunodeficiency virus-infected adults with oral candidiasis

The pharmacokinetics of itraconazole formulated in a hydroxypropyl-beta-cyclodextrin oral solution was determined for two groups of human immunodeficiency virus (HIV)-infected adults with oral candidiasis (group A, 12 patients with CD4+ T-cell count of >200/mm3 and no AIDS, and group B, 11 patients with CD4+ T-cell count of <100/mm3 and AIDS). Patients received 100 mg of itraconazole every 12 h for 14 days. Concentrations of itraconazole and hydroxyitraconazole, the main active metabolite, were measured in plasma and saliva by high-performance liquid chromatography. Pharmacokinetic parameters determined at days 1 and 14 (the area under the concentration-time curve from 0 to 10 h, the maximum concentration of drug in plasma [Cmax], and the time to Cmax) were comparable in both groups. Trough levels in plasma (Cmin) were similar in both groups for the complete duration of the study. An effective concentration of itraconazole in plasma (>250 ng/ml) was reached at day 4. At day 14, Cmin values of itraconazole were 643 +/- 304 and 592 +/- 401 ng/ml for groups A and B, respectively, and Cmin values of hydroxyitraconazole were 1,411 +/- 594 and 1,389 +/- 804 ng/ml for groups A and B, respectively. In saliva, only unchanged itraconazole was detected, and mean concentrations were still high (>250 ng/ml) 4 h after the intake, which may contribute to the fast clinical response. In conclusion, the oral solution of itraconazole generates effective levels in plasma and saliva in HIV-infected patients; its relative bioavailability is not modified by the stage of HIV infection.

Pharmacokinetic interaction of fluconazole and zidovudine in HIV-positive patients

To investigate the interaction of fluconazole and zidovudine in HIV-positive non-smoking male patients with AIDS categorized as CDC group IV we studied two groups, each consisting of 10 male, non-smoking, HIV-positive patients with CDC group IV disease, with the patients in the first group additionally suffering from candida esophagitis. In the first group, the pharmacokinetics of 500 mg oral zidovudine were determined both before and after 7 days of treatment with fluconazole 400 mg/d. In the second group, the pharmacokinetics of 200 mg oral fluconazole were determined before and after 14 days of treatment with zidovudine 4 x 250 mg/d. In order to determine the microsomal enzyme activity, the 6-beta-hydroxycortisol/17-hydroxycorticosteroid ratio and antipyrine pharmacokinetic parameters were determined. 6-beta-hydroxycortisol was quantitated by RIA. The 17-hydroxycorticosteroids were determined by a colorimetric method. Zidovudine (ZDV) and zidovudine glucuronide (GZDV), and the fluconazole and antipyrine plasma and urine concentrations were measured by HPLC. Administration of fluconazole resulted in a significant increase in the half-life of zidovudine and antipyrine (0.97 +/- 0.17 h prior to vs. 1.11 +/- 0. 14 h after fluconazole administration and 11.9 +/- 1.9 h prior to vs. 13.7 +/- 3.0 h after fluconazole, respectively) while the 6-beta-hydroxycortisol excretion decreased significantly (472.3 +/- 80.6 microg/24 h before and 340.6 +/- 82.1 microg/24 h after administration of fluconazole). No changes were found in the GZDV plasma kinetics and the ZDV and GZDV urinary excretion. Treatment with ZDV did not have any impact on the half-life of fluconazole. Administration of zidovudine did, however, result in a significant reduction in antipyrine half-life (11.7 +/- 2.0 h before vs. 9.9 +/- 2.3h after ZDV) and a significant increase in 6-beta-hydroxycortisol excretion (438,7 +/- 138.2 microg/24 h before and 684.6 +/- 157.3 microg/24 h after ZDV). Since the antipyrine clearance is altered after administration of ZDV, it is assumed that zidovudine induces cytochrome P450 enzymes. This effect, however, does not alter the pharmacokinetics of fluconazole. High doses of fluconazole can inhibit the plasma elimination of both antipyrine and zidovudine, but the extent of this inhibitory effect is so small that no clinically relevant accumulation is to be expected.

Elevated cortisol levels in whole saliva in HIV infected individuals

Free cortisol concentrations in unstimulated whole saliva samples, collected at 10.00 to 11.00 h, from 23 unmedicated HIV-positive patients and 14 control subjects were measured by radioimmunoassay. Mean cortisol level (nmol/l +/- SD) was significantly higher in the HIV patients than in control subjects (27.4 +/0 9.3 vs. 10.1 +/- 3.5). Two HIV patients with pseudomembranous candidiasis had the highest saliva cortisol concentrations (mean of 48.5 nmol/l). Two other HIV patients (one with Kaposi's sarcoma and the other with periodontitis) had a mean cortisol value of 29.9 nmol/l. The possibility of plasma contamination of whole saliva in the HIV patients with inflammatory oral mucosal lesions notwithstanding, our findings suggest an increased oral burden of cortisol in both the asymptomatic and symptomatic HIV-infected individuals. Glucocorticoids caused immunosuppression, provide selective growth advantage to various microorganisms including the fungi, and enhance replication or reactivation of latent viruses (e.g. EBV, CMV, Kaposi's sarcoma-associated herpes viruses). Our findings suggest a need to evaluate the relevance of endogenous glucocorticoid excess in blood and saliva to the causation of some major AIDS-associated oral lesions such as candidiasis, Kaposi's sarcoma, oral hairy leukoplakia and necrotizing gingivitis.

[Aberrant p53 protein expression in oral candidal leukoplakia]

Expression of p53 protein in 17 cases of oral candidal leukoplakia (OCL) was studied by immunohistochemistry. p53 protein was identified in all 17 cases (100%) of OCL, and 78% in control cases. The number of p53 positive cells, determined as in per unit of epithelial length, were higher in OCL with epithelial dysplasia than in those without (P < 0.01). Severe dysplasia had the highest number of p53 positive cells. The mean value of p53 positive cells in OCL with simple epithelial hyperplasia was also higher than that in control group. The results indicate that aberrant p53 protein expression exists in OCL and this may be a biological marker for OCL with epithelial dysplasia.

Fluconazole concentrations in saliva from AIDS patients with oropharyngeal candidosis refractory to treatment with fluconazole

Fluconazole (FCZ) has been extensively used as a primary therapy for oropharyngeal candidosis in AIDS patients. Clinical resistance to FCZ is now encountered, often related to decreased susceptibility of the isolate in vitro. We wondered if low levels in saliva play a role in the therapeutic failure, especially in patients complaining of dry mouth. Sixteen AIDS patients treated for oropharyngeal candidosis with FCZ were studied. MICs for the isolates were determined. Serum and saliva samples were collected to measure FCZ levels with a bioassay using paper disks loaded with the clinical specimens. We showed that (i) paper disks were convenient for collecting saliva in patients with dry mouth; (ii) levels in saliva depended on the FCZ dosage regimen but did not correlate with the response to therapy; (iii) correlation between concentrations in saliva and serum was poor and independent of clinical response to treatment, other therapies, or decreased salivation; and (iv) levels in saliva were always lower than MICs in patients who failed to respond to treatment. In conclusion, therapeutic failures are more likely to be related to in vitro resistance of the isolate to FCZ or insufficient dosage regimen than to decreased salivary secretion.

Pharmacokinetic optimization of the treatment of oral candidiasis with fluconazole: studies with a suspension

An open crossover study was performed in 12 healthy subjects to investigate the pharmacokinetics in saliva and plasma of a 100 mg oral dose of fluconazole, administered as either a capsule or as a suspension, the latter being used to rinse the mouth and retained for 2 min before being swallowed. In terms of fluconazole plasma concentrations the capsule and the suspension were essentially bioequivalent. While the saliva concentrations of fluconazole after capsule administration reached their peak at 3.0 +/- 0.8 micrograms/ml 4 h after dosage, administration of the suspension resulted in a mean peak concentration of 551.1 +/- 425.6 micrograms/ml 5 min after ingestion. The saliva concentrations decreased gradually after ingestion of the suspension, but were higher for 4 h than the corresponding levels from the capsule. The area under the curve (AUC) from 0 to 96 h of fluconazole in saliva was 227.7 +/- 73.8 h micrograms/ml after the suspension, compared to 123.5 +/- 25.5 h micrograms/ml after the capsule, indicating that the total drug exposure to the oral mucosa by the salivary route was enhanced more than 80% with use of the suspension. Four h after administration of the suspension, saliva and plasma concentrations of fluconazole were in equilibrium, at a saliva: plasma ratio of around 1.2. Taken together, the present results suggest that the treatment of oral candidiasis with fluconazole may be optimized by use of an oral suspension, as this delivers pharmacologically active levels of the drug to the site of infection by both topical and systemic routes.

Keratinocyte expression of calprotectin in oral inflammatory mucosal diseases

Oral mucosal inflammation evolves in response to microbial pathogens and non-infectious antigens which activate humoral and cell-mediated immunologic processes. Most of these disease processes invoke a leukocyte response culminating in cellular infiltration of the submucosa and, to some degree, transmigration into the epithelium itself. Calprotectin, a leukocyte-derived dimeric protein complex that has potent antibacterial and antifungal effects, has recently been identified in skin and mucosal keratinocytes implying that epithelium may biochemically contribute to the overall mechanism of host defense. In this study, the upregulation of calprotectin as assessed immunohistochemically is pursued for oral diseases of immunopathologic, fungal and viral origin. In lichen planus, candidiasis, herpes virus stomatitis, and oral hairy leukoplakia, calprotectin was found to be expressed to a significantly higher level than in normal control mucosal samples.

Fluconazole once a week as secondary prophylaxis against oropharyngeal candidiasis in HIV-infected patients. A double-blind placebo-controlled study

OBJECTIVE

To assess the efficacy and tolerance of fluconazole (150 mg oral dose, once a week) in the prevention of recurrent oropharyngeal candidiasis in patients with moderate to severe human immunodeficiency virus (HIV) infection.

DESIGN

A randomised, double-blind, placebo-controlled trial.

PATIENTS

Eighty-four patients with moderate to severe HIV infection who had successfully completed two to four weeks treatment with fluconazole for oropharyngeal candidiasis were randomly allocated to receive either placebo or fluconazole. Pre-treatment clinical and laboratory characteristics were similar in the two groups.

OUTCOME MEASURES

Success was classified as absence throughout the course of treatment of clinical evidence of oropharyngeal candidiasis, and failure as recurrence or relapse of symptomatic oropharyngeal candidiasis.

RESULTS

Of 73 evaluable patients the median time to relapse was > or = 168 days in the fluconazole group and 37 days in the placebo group (P < 0.0001). One patient in the placebo group and 18 patients in the fluconazole group completed six months' treatment without clinical relapse (P < 0.001).

CONCLUSION

Fluconazole was well tolerated and prevented clinical relapse of oropharyngeal candidiasis in 71% of patients who completed three months of treatment (95% confidence interval [CI], 55-86) and 58% (95% CI, 41-75) who completed six months of treatment.

Oral candidiasis is associated with low levels of parotid calprotectin in individuals with infection due to human immunodeficiency virus

The level of the antifungal leukocyte protein calprotectin was determined in parotid saliva from 44 individuals with infection due to human immunodeficiency virus (HIV) and 19 healthy HIV-seronegative controls. Nine of the HIV-infected subjects suffered from oral candidiasis. Similar calprotectin levels were found in subjects with HIV infection as a whole group and in controls. When HIV-infected individuals with or without oral candidiasis were compared, the calprotectin level was significantly lower in the former group (67 micrograms/L vs. 216 micrograms/L). We suggest that calprotectin may play a role in the defense against oral candidal infections in HIV-infected patients, although several other antimicrobial factors also are probably operative.

Pharmacokinetics of SCH-39304 in human immunodeficiency virus-infected patients following chronic oral dosing

The pharmacokinetics of SCH-39304, an investigational, orally active, broad-spectrum antifungal agent, were evaluated in 17 adult, human immunodeficiency virus-positive males. Patients were studied on days 1 and 16 and were divided into the following three treatment groups: (i) patients with culture-proven oropharyngeal candidiasis who were not receiving concurrent zidovudine therapy and who were treated with 50 mg of SCH-39304 daily (n = 6); (ii) patients with culture-proven oropharyngeal candidiasis who were receiving concurrent zidovudine therapy and who were treated with 50 mg of SCH-39304 daily (n = 5); and (iii) patients with or without oropharyngeal candidiasis who were receiving concurrent zidovudine therapy and who were treated with 200 mg of SCH-39304 daily (n = 6). All patients received a single daily dose of the study medication for 16 days. Plasma samples for SCH-39304 concentration measurement were collected for 6 h following the initial dose and for 504 h following the day 16 dose. Urine was collected for 24 h following SCH-39304 administration on days 1 and 16. All samples were assayed for SCH-39304 by gas chromatography. Wide intersubject variations in SCH-39304 plasma concentration-versus-time profiles were observed on each study day. Absorption appeared to be slow, with mean day 1 peak plasma SCH-39304 concentrations of 1.2 micrograms/ml at 2.1 h (50 mg) and 3.9 micrograms/ml at 4.0 h (200 mg) after drug administration. Mean peak plasma SCH-39304 concentrations on day 16 were 7.6 micrograms/ml at 4.3 h (50 mg) and 17.2 micrograms/ml at 3.2 h (200 mg) after drug administration. Mean elimination half-lives on day 16 for the 50- and 200-mg daily dosages were 100 and 89 h, respectively. SCH-39304 was cleared primarily unchanged in the urine. Mean areas under the plasma concentration-versus-time curve (from 0 to 24 h) on day 16 reflect a lower than expected increase with the 200-mg/day regimen (314.5 microgram.h/ml) compared with that for the 50-mg/day regimen (139.9 microgram.h/ml), suggesting the potential for reduced bioavailability at higher dosages. No significant effect of concurrent zidovudine therapy on the kinetics of SCH-39304 was observed.

Longitudinal study of parotid saliva in HIV-1 infection

Parotid flow rate and chemistry of 78 HIV + gay/bisexual men and 27 HIV-gay/bisexual controls were compared on a longitudinal basis at 4-month intervals over a 1 yr period for changes indicative of inflammatory or autoimmune diseases of the salivary glands, or reduced protective capacity toward oral opportunistic infection. Parotid saliva was examined for concentrations of sodium, chloride, phosphate, total protein, lysozyme, lactoferrin, secretory IgA, salivary peroxidase, histatin and albumin. Chloride, lysozyme and peroxidase were significantly higher in HIV + at all 3 examinations and increased in concentration over time. Although mean values for stimulated flow rate were not significantly different in the two groups over the year, there was a significant increase in the number of HIV + with reduced flow over time. In 6% of HIV + there was a marked reduction in flow rate and Sjögren's syndrome-like elevations in parotid chemistry but no enlargement. At all examinations low flow rate was significantly related to oral candidiasis; T4 levels were inversely related to oral candidiasis, but not to concentration of salivary components or flow rate; nor was AZT use. As a group the HIV + patients maintained normal flow rate and secreted normal or elevated concentrations of protective proteins. A subgroup, however, exhibited diminished flow over time and an increasing tendency to oral candidiasis and a diminution in output of histatins.

The role of yeasts in oral cancer by means of endogenous nitrosation

Oral leukoplakias, particularly non-homogeneous types, are often invaded by yeasts, with Candida albicans being the dominant species. The more advanced precancerous leukoplakia lesions yield more rarely occurring biotypes of C. albicans, suggesting a causal role for these biotypes in the malignant transformation. N-nitroso-benzylmethylamine (NBMA) is a compound able to induce carcinoma of the esophagus and the oral cavity in the rat. The catalytic potential of yeasts, isolated from leukoplakia lesions and from normal mucosa, to produce NBMA from the precursors N-benzyl-methylamine and nitrite was assessed at pH 6.8. The yeast strains differed in nitrosation potential, ranking from 0 to 1.2 micrograms NBMA/10(6) cells. C. albicans strains of the more rarely occurring biotypes showed the highest nitrosation potential, whereas C. tropicalis, C. parapsilosis, and Torulopsis glabrata were ranked lower. Strains with high nitrosation potential were generally isolated from lesions with more advanced precancerous changes. Thus, further evidence is provided supporting the hypothesis that yeasts play a causal role in oral cancer by means of endogenous nitrosamine production.

Rapid mucosal absorption of topical lidocaine during bronchoscopy in the presence of oral candidiasis

Local anesthetic agents are topically applied during diagnostic procedures such as bronchoscopy. These routine procedures are associated with only rare reports of drug toxicity or extensive systemic drug absorption. We report a case of rapid systemic absorption and elevated plasma lidocaine concentrations following a fiberoptic bronchoscopy procedure in a man with oral candidiasis and lung cancer.

[The proteins of human mixed saliva in galvanism and yeast-induced stomatitis]

Mixed salivary pools of normal subjects and patients with galvanism, yeast-induced stomatitis, and diabetes mellitus were examined. The examinations have revealed elevated alpha-amylase levels in the patients with galvanism and still higher levels of this enzyme in yeast-induced stomatitis and diabetes mellitus. These diseases are also associated with a rise of lactoferrin content and with appearance of fibrinogen degradation products.

The effect of Candida albicans on the permeability of rat palatal epithelium: an ultrastructural and biochemical study

The effect of a palatal acrylic appliance and/or infection with Candida albicans on the permeability of rat palatal epithelium has been investigated. Although normal rats, or rats inoculated with Candida albicans but without a prosthesis, had a barrier to perfused lanthanum, some low-molecular-weight proteins were able to pass through the epithelium. When infection was established by inoculation of Candida albicans under an acrylic plate, the epithelium became permeable to perfused lanthanum. Polyacrylamide gel electrophoresis of perfusates showed that a selective permeability to proteins was retained in such animals. Removal of acrylic plates from infected animals resulted in healing and restoration of the barrier to lanthanum.

Life history of experimentally induced acute oral candidiasis in the rat

A simple method of oral inoculation with Candida albicans was used to study the course of candidiasis in the rat. Changes in the pattern of keratinization of the epithelium were prevalent with minimal involvement of the underlying corium at the site of infection.