Immunological investigations in vaginal mycoses

Investigations by cell-mediated immunologic tests and therapeutic trials with thymopentin in vaginal mycoses

Objective: According to unsatisfactory therapeutic results in patients with chronically recurrent vaginal candidosis, we investigated if immunologic patient factors could be found and treated.

Methods: In 42 women with chronically recurrent and 20 women with acute Candida albicans vulvovaginitis, as well as 14 women with C. glabrata vaginitis, the following investigations were carried out: identification of yeast species; quantification of T lymphocytes and their subpopulations in sera; proliferation tests of T lymphocytes in vitro; treatment of 18 patients with chronically recurrent vaginal candidosis with the synthetic T-lymphocyte- stimulator thymopentin; and, finally, control of the above-mentioned parameters in the clinical course.

Results: Women with C. albicans vulvovaginitis showed fewer T lymphocytes and subpopulations in the peripheral blood than healthy women. Only the number of non-specific killer (NK) cells, however, was significantly lower in cases of acute C. albicans vulvovaginitis. In women with C. glabrata vaginitis, the number of T lymphocytes in the blood was within the normal range. In vitro proliferation tests using mitogens, bacterial antigens, and commercially available candida antigens with and without addition of thymopentin were carried out on the T lymphocytes of women with chronically recurrent C. albicans vulvovaginitis. These tests revealed no significant differences compared with the other patients with C. albicans infections. The patients were treated with thymopentin. Those women who revealed an increase of initially low numbers of T-helper cells recovered from vaginal candidosis after thymopentin treatment.

Conclusions: The peripheral T lymphocytes may be diminished in patients with chronically recurrent C. albicans vaginitis, and immunologic treatment can reduce the relapse rate.

Candida infections of the genitourinary tract

All humans are colonized with Candida species, mostly Candida albicans, yet some develop diseases due to Candida, among which genitourinary manifestations are extremely common. The forms of genitourinary candidiasis are distinct from each other and affect different populations. While vulvovaginal candidiasis affects mostly healthy women, candiduria occurs typically in elderly, hospitalized, or immunocompromised patients and in neonates. Despite its high incidence and clinical relevance, genitourinary candidiasis is understudied, and therefore, important questions about pathogenesis and treatment guidelines remain to be resolved. In this review, we summarize the current knowledge about genitourinary candidiasis.

Immunopathogenesis of recurrent genital candidosis in women

Introduction. There are more and more women that suffer from chronic recurrent genital candidiasis. At the beginning of the research in this field the researchers usually studied the properties of the microorganism then nonspecific resistance of the vaginal mucosa, possibility of endogenous and exogenous reinfection, hormonal status of women in order to determine the cause of the recurrent genitall candidosis. After numerous studies, only the risk factors were determined, but not the very cause of the recurrence of this fungal infection. The following investigation encompassed examination of the immunity of the vaginal mucosa, as welll as the influence of the system cellular immunity to the course of the vaginal fungal infection. Results of those studies show that neither hyporeactivity, nor the disregulation of the system cellular immunity has influence to the course of the recurrent genital candidosis. Conclusion. Based on the existence of the antigen presenting cells and phenotypically different T- lymphocytes in the vaginal mucosa, it was determined that this mucous membrane represents immunocompetent tissue, and accordingly, one may assume that the cause of the recurrent genital candidosis may lie in disregulation of the local immune response to the Candida sp. antigens.

Post-menopausal recurrent vaginal candidiasis: effect of hysterectomy on response to treatment, type of colonization and recurrence rates post-treatment

INTRODUCTION

Post-menopausal patients are still susceptible to be colonized by fungal organisms despite being estrogen-deprived. Symptomatic vulvovaginal candidiasis, although a rare occurrence in post-menopausal patients, can be diagnosed in about one third of the patients. The purpose of our study was to investigate in post-menopausal patients with recurrent vulvovaginal candidiasis the effect of hysterectomy on response to treatment, the type of colonization and the recurrence rates after treatment.

MATERIALS

Forty-seven menopausal patients with symptomatic recurrent vulvovaginal colonization were evaluated between January 1995 and August 2002. The study was a retrospective cohort chart review and included complete history and physical examination, basic metabolic blood panel, colposcopy, wet mount, bacterial and fungal cultures. Twenty-three patients had hysterectomy and 24 were not hysterectomized. All the patients received daily fluconazole therapy for 30 days. They were then re-evaluated at 1, 3 and 6 months and retreated if symptomatic and culture positive.

RESULTS

The 2 groups of patients were comparable regarding age, number of years of recurrent colonization, number of previous antifungal treatments and previous, current use of hormone replacement therapy. None used vaginal douching. The 2 groups of patients showed statistical differences regarding: colonization by Candida albicans (P<0.01), colonization by Candida glabrata (P<0.05), colonization by Candida stelloidea (P<0.01), recurrence after 3 months (P<0.05) and 6 months (P<0.05), response to one course of therapy (P<0.02) and need for multiple treatments (P<0.03).

CONCLUSIONS

Hysterectomized post-menopausal patients with recurrent vulvovaginal fungal colonization seems to be more propense to harbor more aggressive and resistant fungi. Post-menopausal recurrent vaginal candidiasis: effect of hysterectomy on response to treatment, type of colonization and recurrence rates post-treatment.

Candida albicans-secreted aspartic proteinases modify the epithelial cytokine response in an in vitro model of vaginal candidiasis

Secreted aspartyl proteinases (Saps) are important virulence factors of Candida albicans during mucosal and disseminated infections and may also contribute to the induction of an inflammatory host immune response. We used a model of vaginal candidiasis based on reconstituted human vaginal epithelium (RHVE) to study the epithelial cytokine response induced by C. albicans. In order to study the impact of the overall proteolytic activity and of distinct Sap isoenzymes, we studied the effect of the proteinase inhibitor pepstatin A on the immune response and compared the cytokine expression pattern induced by the wild-type strain SC5314 with the pattern induced by Sap-deficient mutants. Infection of RHVE with the C. albicans wild-type strain induced strong interleukin 1alpha (IL-1alpha), IL-1beta, IL-6, IL-8, IL-10, granulocyte-macrophage colony-stimulating factor, gamma interferon, and tumor necrosis factor alpha responses in comparison with cytokine expression in noninfected tissue. Addition of the aspartyl proteinase inhibitor pepstatin A strongly reduced the cytokine response of RHVE. Furthermore, SAP-null mutants lacking either SAP1 or SAP2 caused reduced tissue damage and had a significantly reduced potential to stimulate cytokine expression. In contrast, the vaginopathic and cytokine-inducing potential of mutants lacking SAP4 to SAP6 was similar to that of the wild-type strain. These data show that the potential of specific Saps to cause tissue damage correlates with an epithelium-induced proinflammatory cytokine response, which may be crucial in controlling and managing C. albicans infections at the vaginal mucosa in vivo.

Beta-1,2-mannosylation of Candida albicans mannoproteins and glycolipids differs with growth temperature and serotype

Increasing the growth temperature from 28 to 37 degrees C reduced the expression of beta-1,2-oligomannoside epitopes on mannoproteins of Candida albicans serotypes A and B. In contrast, beta-1,2-mannosylation of phospholipomannan (PLM) remained constant despite a slight decrease in the relative molecular weight (M(r)) of this compound. At all growth temperatures investigated, serotype A PLM displayed an M(r) and an antigenicity different from those of serotype B PLM when they were tested with a panel of monoclonal antibodies.

Candida glabrata: review of epidemiology, pathogenesis, and clinical disease with comparison to C. albicans

Until recently, Candida glabrata was considered a relatively nonpathogenic commensal fungal organism of human mucosal tissues. However, with the increased use of immunosuppressive agents, mucosal and systemic infections caused by C. glabrata have increased significantly, especially in the human immunodeficiency virus-infected population. A major obstacle in C. glabrata infections is their innate resistance to azole antimycotic therapy, which is very effective in treating infections caused by other Candida species. Candida glabrata, formerly known as Torulopsis glabrata, contrasts with other Candida species in its nondimorphic blastoconidial morphology and haploid genome. C. glabrata currently ranks second or third as the causative agent of superficial (oral, esophageal, vaginal, or urinary) or systemic candidal infections, which are often nosocomial. Currently, however, there are few recognized virulence factors of C. glabrata and little is known about the host defense mechanisms that protect against infection. Two established animal models (systemic and vaginal) have been established to study treatment, pathogenesis, and immunity. Treatment of C. glabrata infections can include azoles but often requires amphotericin B or flucytosine. This review summarizes all known clinical and experimental information about C. glabrata infections with comparisons to C. albicans as a means of contrasting the two species commonly observed and emphasizing the many recognized differences.