Thrush and fever as markers of immune competence in the era of highly active antiretroviral therapy

The presence of clinical manifestations of HIV-1 infection is one measure of immune function failure. We examined the occurrence of clinical manifestations of HIV-1 infection, in particular fever and oral thrush, before and after the initiation of highly active antiretroviral therapy (HAART). Using data collected from 645 participants in the Multicenter AIDS Cohort Study (MACS) who used HAART, 7517 person-visits from January 1992 through March 2000 were stratified by time relative to HAART initiation (> or =1 year preinitiation, <1 year preinitiation, >1 year postinitiation, and > or =1 year postinitiation) and CD4+ T cell count (< or =100, 101-200, 201-350, and >350 cells/microl). Multivariate logistic regression was used to assess the relationship between HAART, CD4+ T cell count, and each self-reported symptom (oral hairy leukoplakia, diarrhea, fever, and oral thrush). After initiation of HAART, clinical manifestations of HIV-1 infection continued to occur and, similar to patterns seen before HAART, were more likely at lower CD4+ T cell counts than at higher (p < 0.001). Except for diarrhea, symptoms did not occur more frequently after HAART. Rather, beyond 1 year after initiation of HAART, there was less oral thrush even at the same CD4+ T cell count. These results provide evidence that increases in CD4+ T cell count due to HAART represent a reconstitution of immune function.

Oral manifestations related to immunosuppression degree in HIV-positive children

Oral manifestations often found in HIV-infected children are frequently the first clinical sign of the infection. This article aims to report the prevalence of oral manifestations in soft tissues and their relationship with the degree of immunosuppression in 80 HIV-infected patients (average age 6.30 +/- 3.32 years old) at the IPPMG-UFRJ. Thirty children (38%) presented some type of oral lesion and the percentage of CD4 was lower than that found in lesion-free children (p < 0.05); 22.5% presented candidiasis, 17.5% gingivitis, 8.8% enlargement of parotids, 1.3% herpes simplex and 1.3% hairy leukoplakia. Of the 30 children with lesions, 70% showed severe immunosuppression, 23.3% moderate immunosuppression and in only 6.7% was immunosuppression absent. Oral manifestations were directly related to the degree of immunosuppression and such lesions can be considered as indicators of the progression of the HIV infection in children.

Oroesophageal candidiasis is lethal for transgenic mice with combined natural killer and T-cell defects

Germfree transgenic epsilon 26 (Tgepsilon26) mice, which express the full-length human CD3epsilon gene, have combined defects in natural killer (NK) cells and T cells were found to be extremely susceptible to oroesophageal (palate, tongue, esophagus) and gastric (cardia-antrum section) candidiasis. The gnotobiotic Tgepsilon26 mice die, apparently from severe oroesophageal candidiasis, within 2-4 weeks after their alimentary tracts are colonized with Candida albicans. The Tgepsilon26 mice manifest resistance to acute systemic candidiasis (intravenous injection) and to systemic candidiasis of endogenous origin for the first 2 weeks after their alimentary tracts are colonized with C. albicans. Granulocyte depletion data suggest that granulocytes, in the absence of functional NK cells and T cells, can protect Tgepsilon26 mice from acute systemic candidiasis and from systemic candidiasis of endogenous origin, for at least 14 days after alimentary tract colonization. Granulocytes and macrophages, in the absence of NK cells and T cells, are unable to protect Tgepsilon26 mice from lethal oroesophageal candidiasis and systemic candidiasis of endogenous origin which was evident in moribund Tgepsilon26 mice 2-4 weeks after colonization. Thus, non-T cells (i.e., NK cells) and T cells play important roles in resistance to oroesophageal and systemic (acute and of endogenous origin) candidiasis.

Increased serum and salivary immunoglobulins against Candida albicans in HIV-infected patients with oral candidiasis

The aim of this study was to explore anti-Candida albicans systemic and mucosal humoral responses against Candida virulence antigens such as somatic antigen and secreted aspartic proteases (Saps) in HIV-infected patients with oral candidiasis. Twenty-eight subjects were included in the study: 11 HIV-positive patients without oral candidiasis (group A), 6 HIV-positive patients with oral candidiasis (group B) and 11 HIV-negative healthy controls (group C). Total IgA, IgG and IgM concentrations and antibodies to C. albicans (somatic antigen, Sap1, Sap6) were measured in serum and saliva. We developed a time-resolved immunofluorometric assay with biotin and europium-labeled streptavidin for this purpose. Salivary total IgA, IgG and IgM concentrations were higher in group B. IgA, IgG and IgM anti-C. albicans antibodies (against somatic antigen, Sap1, Sap6) were higher in saliva and serum from patients from group B compared with patients from group A and controls. Our results suggest that, in oral candidiasis, HIV-infected patients have a high mucosal response, specifically directed against C. albicans virulence antigens, such as somatic antigen, Sap1 and Sap6.

Gender differences in human immunodeficiency virus-related oral lesions: an Italian study

OBJECTIVE

The purpose of this study was to investigate the relationship between oral lesions and gender, age, CD4(+) cell count, human immunodeficiency virus-1 (HIV-1) viral load, antiretroviral therapy, and route of transmission in a group of HIV-infected (HIV+) persons from the Mediterranean region.

STUDY DESIGN

The participants in this study were HIV+ adults who sought dental care between January 1999 and June 1999 in the Department of Oral Medicine (University of Palermo, Italy).

RESULTS

One hundred thirty-six HIV+ adults came in for an initial oral examination. Their mean age was 35.2 years (SD +/- 7.97), and 33% were women. Their mean CD4(+) cell count was 325.3 x 10(6) /L (SD +/- 225.8), and their HIV-1 viral load was 39,168.3 copies/mL (SD +/- 144,256.1). Oral lesions were found in 47% of the study group, as well as in 56.5% of women (n = 46) versus 45.5% of men (n = 90; P =.05). Oral candidiasis was the most common disease; it is significantly associated with women (P =.004), CD4(+) cell count (P =.005), and HIV-1 viral load (P =.0003). No significant relationships were found between any types of oral lesions and age, antiretroviral therapy, or route of transmission (P >.2).

CONCLUSION

The prevalence of HIV-related oral lesions was significantly higher in women than in men, especially for oral candidiasis, the most common lesion observed related to immune status and HIV-1 viral load.

A therapeutic vaccine for mucosal candidiasis

Persistent and recurrent infection of mucosal surfaces with Candida albicans is common, ranging from a nuisance to a life threatening clinical problem. No effective prophylactic or therapeutic vaccine has been developed. We have studied a mouse model of oral candida infection to identify regulatory and effector molecules of T cell activation as parameters of induced immunity, and here describe the use of this model to determine an optimal immunisation strategy. Oral immunisation with the blastospore yeast form (but not subcutaneous immunisation) induced clinical immunity, with a shift in parameters of cytokine response characterised by an early and sustained production of both IFN-gamma and IL-4 from antigen-stimulated cervical node T lymphocytes.

Longitudinal study of anti-Candida albicans mucosal immunity against aspartic proteinases in HIV-infected patients

Oropharyngeal candidiasis (OPC), mainly caused by Candida albicans, is commonly observed in HIV-infected patients. Secreted aspartic proteinases (Saps) are virulent agents involved in adherence to the mucosal surface and in tissue invasion. The immune secretory response to these agents was investigated in 15 HIV-infected patients, during oral yeast colonization and episodes of oropharyngeal candidiasis (OPC), in a 1-year longitudinal study. We developed an avidin-biotin-amplified immunofluorometric assay for the detection of specific immunoglobulins G, A, and M against somatic, Sap2 and Sap6 antigens. We report increases in anti-somatic, anti-Sap2, and anti-Sap6 salivary antibodies in patients with OPC. Over the 1-year period, not only OPC episodes but also variations in yeast colonization levels were correlated with variations in salivary anti-Sap6 antibody levels. Our results show the ability of HIV-infected patients to produce high levels of salivary antibodies; however, these antibodies were not efficient in limiting candidal infection, probably because of cellular cooperation deficiency and the enhanced virulence of the infecting strain.

Candida-specific systemic cell-mediated immune reactivities in human immunodeficiency virus-positive persons with mucosal candidiasis

Oropharyngeal candidiasis (OPC), as opposed to vulvovaginal candidiasis (VVC), is a common opportunistic infection in human immunodeficiency virus (HIV)-positive persons that correlates with reduced CD4 T cell counts. Although cell-mediated immunity (CMI) by CD4 Th1-type cells is considered to be the predominant host defense against mucosal candidiasis, the immune factors associated with susceptibility to OPC in HIV-positive persons are not well understood. This study investigated Candida-specific systemic CMI in HIV-positive persons with OPC and/or VVC. Reductions in delayed skin test reactivity to Candida antigen were observed in HIV-positive persons with CD4 cell counts <200 cells/microL, irrespective of the presence of mucosal infection. Likewise, despite the correlate of OPC with reduced CD4 cell counts in HIV-positive persons, differences in Candida-specific peripheral blood mononuclear cell proliferation and Th1/Th2 cytokine production between HIV-positive and HIV-negative persons were not consistent in a manner to suggest that deficiencies in Candida-specific systemic CMI account solely for the susceptibility to OPC.

Heterogeneity of oral isolates of Candida albicans in HIV-positive patients: correlation between candidal carriage, karyotype and disease stage

Opportunist infections involving Candida albicans often develop in HIV-positive patients and oral lesions tend to become more frequent as the disease progresses. Previous studies have shown contrasting results concerning the variability of the pulsed-field gel electrophoresis (PFGE) subtypes of C. albicans observed in HIV-positive patients. Carriage of C. albicans was determined by an oral rinse technique; 41 strains of C. albicans (78% serotype A and 22% serotype B) were isolated. There was a direct correlation between candidal load (cfu/ml) and the blood HIV load, whereas there was an inverse correlation with the stage of disease and the CD4 cell counts. The PFGE patterns of isolates were variable with regard to the number and positions of bands. The variability of the band sizes in some run positions showed a Gaussian distribution. Generally, the most frequent size variants were associated with the strains with the highest cfu/ml and lowest CD4 counts (< or =200 cells/microl). These findings suggest a possible strain selection over time during disease progression, especially in HIV-positive subjects with low CD4 counts.

Serum and salivary antibodies to a mycobacterial 65-kDa stress protein are elevated in HIV-positive patients and modified by oral candidiasis

Serum immunoglobulin G (IgG) and IgA, and salivary IgA antibodies to a mycobacterial stress protein (mSP65) were determined in human immunodeficiency virus (HIV)-positive patients, acquired immunodeficiency syndrome (AIDS) patients and HIV-negative controls with or without oral candidiasis. Serum IgG antibodies were elevated in patients with HIV infection and AIDS and especially in subjects with candidiasis compared with controls (P < 0.02, P < 0.005). This was not apparent with serum IgA. In the absence of candidiasis, salivary IgA antibodies were elevated in HIV-positive patients compared with AIDS (P < 0.005) patients and healthy controls (P = 0.001). The relative avidity of serum IgG antibodies to mSP65 in controls with candidiasis was lower than healthy controls (P < 0.0001). In saliva there was a decrease in the relative avidity of IgA antibodies in AIDS patients with candidiasis compared with HIV patients (P < 0.03). In patients without candidiasis, the relative avidity was higher in HIV patients than healthy controls (P = 0.02). The results suggest that HIV infection leads to raised serum and salivary antibodies to heat shock proteins. Concurrent Candida infection may modify both the titer and relative avidity differently for serum and saliva.

Cellular and cytokine correlates of mucosal protection in murine model of oral candidiasis

Host protection against Candida albicans infection in a model of oral candidiasis involving infection-prone [DBA/2 (H-2(d))] and less infection-prone [BALB/c (H-2(d))] mouse strains was analyzed in terms of antibody and cellular responses, and in terms of cytokine patterns from regional lymph node cells. There was a selective expansion of gamma/delta(+) T-cell receptor cells, which correlated with the patterns of colonization in both mouse strains, with higher numbers of gamma/delta T cells detected in BALB/c mice. Antigen-induced T-cell proliferation was significantly higher in BALB/c mice than in DBA/2 mice. Higher levels of serum immunoglobulin G (IgG) and salivary IgA antibodies were detected in BALB/c mice than in DBA/2 mice, but only after the infection was cleared. The cervical lymph node cells from infected mice were assessed for interleukin-4 (IL-4), IL-12, and gamma interferon (IFN-gamma) mRNA gene expression by reverse transcription-PCR and protein production in the culture supernatants following restimulation in vitro. In BALB/c mice, an early increase in levels of IL-4, IFN-gamma, and IL-12 correlated with rapid elimination of C. albicans. In DBA/2 mice, where resolution of infection was delayed, IL-4 message expression was delayed and the IL-4 secretion level was lower. Neutralization of IL-4 by multiple injections of an anti-IL-4 monoclonal antibody in BALB/c mice resulted in increased carriage rate and delayed clearance of the yeasts. Collectively, the data suggest that the T-cell response to C. albicans in the regional lymph nodes which correlates best with rapid oral clearance of C. albicans is a balanced Th0 cytokine response involving early secretion of both IFN-gamma and IL-4.

Sensitivity, specificity, and positive predictive value of oral opportunistic infections in adults with HIV/AIDS as markers of immune suppression and viral burden

OBJECTIVES

The purpose of this study was to assess the use of human immunodeficiency virus (HIV)-related oral opportunistic infections as markers of immune suppression and viral burden in adults with HIV/acquired immunodeficiency syndrome (AIDS).

METHODS

The population consisted of a single institution observational cohort involving 606 patients with HIV/AIDS with CD4 count data and 277 with plasma viral load measurements examined between 1995 and 1999 for the presence of oral manifestations of HIV. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value is reported for the association of specific oral lesions and lesion sets with CD4 counts <200 cells/mm(3) and with plasma HIV RNA >/=20,000 copies/mL.

RESULTS

Lesions with moderate-to-high PPVs for CD4 <200 cells/mm(3) were as follows: Kaposi's sarcoma (100%; P =.035), pseudomembranous candidiasis (82. 2%; P <.001), linear gingival erythema (70.0%; P =.015), hairy leukoplakia (66.3%; P <.001), angular cheilitis (60.0%; P =.128), and erythematous candidiasis (58.3%; P =.061). Necrotizing ulcerative periodontal diseases, HIV salivary gland disease, oral ulcers, and oral warts had PPVs below 50%. Concurrent infection with candidiasis and hairy leukoplakia had the highest PPV of 89.3%; P <. 001. PPVs for HIV RNA >/=20,000 copies/mL ranged from 27.3% to 100%, with significant association only for pseudomembranous candidiasis.

CONCLUSIONS

Specific common oral lesions are strongly associated with immune suppression, as measured by CD4 cell counts, and are modestly associated with high viral burden, thus serving as potential clinical markers of HIV viremia and the consequent destruction of the immune system with progressive HIV disease.

Interleukin 6, tumor necrosis factor alpha and their soluble receptors in the blood serum of patients with denture stomatitis and fungal infection

Determinations of the blood serum levels of interleukin 6 (IL-6), tumor necrosis factor alpha (TNF-alpha) and their soluble receptors (sIL-6R, sTNFR) in denture stomatitis patients (DS) were performed. Serum levels of interleukins and their soluble receptors were measured using the ELISA method. In all examined patients mycological diagnostics were conducted using API 20C AUX stripe tests and an automatic ATB machine. Results were compared with those of healthy denture wearers (D), and controls (C). In DS patients, yeasts were isolated in 90.9%, in D in 66.7% of cases. The most often isolated species in both groups was Candida albicans. Mean concentrations of IL-6 and TNF-alpha were statistically significantly higher in DS and D groups compared to controls. Mean concentrations of sIL-6R were similar in all groups; however, concentrations of sTNFR in both DS and D groups were significantly lower compared to controls. There were no correlations found between values of IL-6 and TNF-alpha nor between examined interleukins and their soluble receptors.

Influence of environmental pH on the reactivity of Candida albicans with salivary IgA

Salivary secretory IgA reacts with a group of heat-shock mannoproteins preferentially expressed on Candida albicans yeast cells and germ tubes grown at 37 degrees C. Since other environmental factors can also modulate the expression of those antigens, we have investigated the influence of the pH of the culture medium on the expression of the antigens reacting with human salivary IgA by C. albicans. By indirect immunofluorescence, yeast cells grown in Sabouraud glucose broth at 37 degrees C showed a statistically significant increase in reactivity with salivary IgA (p < 0.0001) when compared with cells grown at 25 degrees C at the 4 pH values studied (3.3, 5.9, 7.5, and 9.5), the highest reactivity and the major heat-shock effect being observed at pH 5.9. The decrease in reactivity with salivary IgA observed in C. albicans cells grown at pH values of 3.3 and 9.5 was confirmed by Western blotting. Salivary IgA reacted with polydispersed materials from the cell walls of molecular masses > 55 kDa, which were more expressed at neutral pH than at acidic or alkaline pH values. A similar reactivity was observed when the antigenic extracts were stained with an antiserum directed against oligosaccharides present in antigen 6 of C. albicans serotype A. The differences in reactivity presented by salivary IgA may be related to a decrease in the expression of polysaccharides present on the surfaces of the yeast cells of C. albicans grown at acidic or alkaline pH values. The low reactivity of salivary IgA with C. albicans cells grown at acidic pH values may help to explain the association between acidic saliva and the carriage of Candida in the oral cavity, as well as with oral candidiasis.

Functions of oral candidiasis episodes that are highly prognostic for AIDS

Although oral candidiasis lesions are widely recognized as markers for AIDS, the relative prognostic significance of functions of these episodes has not been examined. We compare the associations with time to AIDS of one fixed and six time-dependent metrics of oral candidiasis lesions, including proximity of a lesion to seroconversion, any candidiasis history, and recency of a lesion. We show in Cox regression models that two metrics are clinically and statistically far more significant than the others, alone or in combination: any history of candidiasis since HIV seroconversion, and recency of a candidiasis episode. The latter metric indicates that the risk of an AIDS diagnosis is high during a candidiasis episode. The results hold for two cohorts of male seroconverters, 627 haemophiliacs and 196 men who have sex with men. Identification of highly prognostic functions of a patient's oral candidiasis history allows clinicians and researchers to focus on these aspects of the history and to omit extraneous information from data collection. Our method extends well beyond candidiasis and AIDS, and may shed light on associations of covariates with outcomes in a variety of settings.

Synergistic immunosuppression by candida in HIV infection: a cytokine based analysis

Candida is a common opportunistic pathogen in HIV infection and is regarded a signal infection for progression to AIDS. Cytokine imbalances between Th1/Th2 groups have been described in both candida and HIV infections. A study was undertaken to assess the role of candida in furthering immunosuppression in HIV infection based on cytokine levels and CD4 cell counts. 30 Indian subjects were enrolled; 10 HIV positive patients with and 10 without mucosal candidiasis and 10 age matched controls. Th1 cytokines; interleukin (IL) 2, IL 12 and interferon (IFN) gamma, Th2 cytokines; IL 4, IL 6, IL 10 and tumor necrosis factor (TNF) alpha with CD 4 cell counts were estimated using ELISA in all subjects. CD4 cell counts were reduced in both patient groups as compared to controls; significantly more in patients with both HIV and candida infections. There was a decrease in Th1 cytokine levels in all patients; lower levels of Th1 cytokines were seen in patients with both infections. Among the Th2 cytokines, there was a significant increase in the levels of IL 6, IL 10 and TNF alpha in both patient groups; IL 10 and TNF alpha values were significantly raised in patients with dual HIV and candida infections as compared to the other patients. There was no difference in IL 4 values across the subject groups. A positive correlation between CD4 cell counts and Th1 cytokine levels and a negative correlation with Th2 cytokines were noted; these were stronger in patients with both HIV and candidiasis. Thus, there was a Th1/Th2 cytokine imbalance with CD4 cell count reduction in all HIV infected patients, which was more pronounced in patients with both infections. It can be concluded that, owing to the depressed CD4 cell count and Th1 response and increased Th2 cytokines in patients with both candidiasis and HIV as compared to patients with only HIV candidiasis may have a synergistic immunosuppressive effect with HIV in patients with dual infections.

Pathology and clinical correlates in oral candidiasis and its variants: a review

Although Candida albicans is well recognised as the major agent of oral candidiasis, it is not clear why several variants such as pseudomembranous (PC), erythematous (EC) and hyperplastic candidiasis (HC) manifest in different individuals, sometimes singly and on other occasions, in combination. The present review focuses on recent histopathologic and immunocytochemical studies as well as the pathogenic attributes of the yeast, in an attempt to address the following queries. (1) Do histopathologic studies of the different variants of candidiasis in immunocompetent and immunocompromised individuals help explain these varying manifestations? (2) Under what circumstances does oral candidiasis manifest as a pseudomembranous rather than an erythematous lesion or vice versa? (3) Are there differences in immunoreactivity in closely adjacent mucosae so that the variable presentation of such lesions reflect differences in the local mucosal immune system? Recent studies of PC, EC and HC offer some insights into the pathogenic mechanisms involved. Histopathologic and immunohistochemical finding in cases of PC and EC in HIV-infected patients and controls appear to be comparable, with a marked reduction or even an absence of CD4+ cells. The latter phenomenon is marked in PC compared with the EC, and explicable in terms of a breakdown of the local immune response in the former, and a hypersensitivity reaction against Candida antigens in the latter. Hyperplastic candidiasis on the other hand could be considered a superficial cellular reaction against the pathogen, which cannot entirely be eradicated by the systemic or local host immune response. The virulent attributes of the fungus, such as the production of extracellular proteinases, do significantly differ within and between species and thereby play a contributory role in the genesis of the clinical variants. Although the available data do give a tantalising glimpse of the contributory mechanisms for the aetiopathology of PC, EC and HC, further research is warranted to elucidate response of the host to this ubiquitous fungal pathogen.

Further characterization of human salivary anticandidal activities in a human immunodeficiency virus-positive cohort by use of microassays

Salivary anticandidal activities play an important role in oral candidal infection. R. P. Santarpia et al. (Oral Microbiol. Immunol. 7:38-43, 1992) developed in vitro anticandidal assays to measure the ability of saliva to inhibit the viability of Candida albicans blastoconidia and the formation of germ tubes by C. albicans. In this report, we describe modifications of these assays for use with small volumes of saliva (50 to 100 microl). For healthy subjects, there is strong inhibition of blastoconidial viability in stimulated parotid (75%), submandibular-sublingual (74%), and whole (97%) saliva, as well as strong inhibition of germ tube formation (>80%) for all three saliva types. The susceptibility of several Candida isolates to inhibition of viability by saliva collected from healthy subjects is independent of body source of Candida isolation (blood, oral cavity, or vagina) or the susceptibility of the isolate to the antifungal drug fluconazole. Salivary anticandidal activities in human immunodeficiency virus (HIV)-infected patients were significantly lower than those in healthy controls for inhibition of blastoconidial viability (P < 0.05) and germ tube formation (P < 0. 001). Stimulated whole-saliva flow rates were also significantly lower (P < 0.05) for HIV-infected patients. These results show that saliva of healthy individuals has anticandidal activity and that this activity is reduced in the saliva of HIV-infected patients. These findings may help explain the greater incidence of oral candidal infections for individuals with AIDS.

Glycaemic disorders in denture stomatitis

The prevalence of glycaemic disorders was investigated in native Upper-Austrians with Candida-associated denture stomatitis. All patients with previously unknown diabetes mellitus were subjected to an oral glucose tolerance test (OGTT) and as a result diabetes was diagnosed in 13% of the patients over 50 years of age. Thirty-five percent of all inspected patients over 50 years of age with denture stomatitis had type 2 diabetes mellitus and 36% had impaired glucose tolerance (IGT). The correlation between Candida-associated denture stomatitis and diabetes mellitus indicates a means for the early diagnosis of diabetes. Hyperglycaemia could not be a predisposition to denture stomatitis, since all patients with denture stomatitis in the age-bracket 26-50 years were without diabetes and only very few of the older patients with diabetes were obese. The correlation between Candica-associated denture stomatitis and type 2 diabetes mellitus could be traced back to a reduced resistance to Candida that preceded the diabetes.

Fungi of Candida species in the pharynx and some parameters of humoral and cellular immunity in patients

BACKGROUND

The pharynx is one of the open spaces where fungi can settle easily. The purpose of the investigation was to estimate an overall prevalence of fungal colonization and some parameters of humoral and cell immunity.

METHODS

The study consisted of 167 patients, from whom swabs of the posterior and lateral part of the pharynx were taken for mycological examinations, during which tests based on morphological and biochemical (zymogram, auxanogram) characteristics were used. In all cases, the leukocyte count, overall protein level, and protein individual fractions were determined. Also determined were the levels of IgA, IgM and IgG immunoglobulin in blood serum, and IgA immunoglobulin (S-IgA) in saliva. At the same time, blastic transformation test and rosette tests: E (ER) to determine lymphocytes T count, as well as EA (EAR) and EAC (EACR) to detect lymphocytes B, were performed.

RESULTS

Fungal infection was found in 2/3 of patients. Fungi were classified as belonging to six species of Candida, which are considered to be important etiological factors of mycoses; the most common fungus was Candida albicans (in 86 cases). All cases of candidosis showed a decreased count of lymphocytes T, with their function deficient, and most of them a low S-IgA level in saliva (over three times lower than the norm) and high mean values for sedimentation rate.

CONCLUSIONS

In patients in our study the IgA level in serum remained within normal limits, yet the ratio fo this fraction to other immunoglobulins deviated from that in healthy individuals.

Frequency of oropharyngeal candidiasis in HIV-infected patients on protease inhibitor therapy

OBJECTIVE

The purpose of this study was to investigate the effect of HIV-1 protease inhibitors on the frequency of oropharyngeal candidiasis in HIV-infected patients.

STUDY DESIGN

A clinical and analytic follow-up was carried out to determine the number of episodes of oropharyngeal candidiasis during HIV-1 protease inhibitor therapy and the relation of this incidence to the CD4 lymphocyte count and circulating neutrophils level. Seventy-five HIV-positive patients were selected, and HIV-1 protease inhibitor therapy was administered to each patient over a minimum of 6 months. These patients did not receive long-term preventive antifungal therapy for oral candidiasis, even as secondary prophylaxis against cryptococcosis. Results were compared with those obtained during the previous 6 months, during which patients had been treated only with reverse transcriptase inhibitors.

RESULTS

At least one episode of oropharyngeal candidiasis was seen in 56% (42/75) of patients during reverse transcriptase inhibitor therapy and in only 9.3% (7/75) of patients after the initiation of protease inhibitor therapy. The number of relapses decreased significantly when the 2 follow-up periods were compared (P<.0001). The CD4 and CD8 lymphocyte counts increased significantly with protease inhibitor therapy (P<.001 and P<.05, respectively). During reverse transcriptase inhibitor treatment, the probability of the presentation of oropharyngeal candidiasis correlated with falling CD4 counts (P<.0001). The HIV-1 protease inhibitor therapy was associated with a significant increase in the neutrophil count (P<.01). The probability of the occurrence of some episode of candidiasis correlated inversely with the circulating neutrophil level (P<.05).

CONCLUSIONS

Protease inhibitor therapy decreases the frequency of HIV-related oropharyngeal candidiasis. The mechanism involved is unknown, but it can be speculated that a reduction of the viral load increases the number of intact T helper cells, which in turn enhances the number of circulating polymorphonuclear neutrophils and regulates their function by means of colony-stimulating factors.

The relative pathogenicity of Candida krusei and C. albicans in the rat oral mucosa

The relative pathogenicity of Candida krusei and C. albicans was investigated by assessing their colonisation and infectivity of the Sprague-Dawley rat oral mucosa. During an initial 21-week period with intermittent oral inoculation, both Candida spp. demonstrated variable surface colonisation of the oral mucosa. After 3 days of oral inoculation, both yeast species were recovered from all animals. During the 21-week period the mean oral load of C. albicans in the control group of rats varied between (26-274) x 10(1) cfu/ml whereas the two test groups of rats carrying C. krusei CK9 and CK13 had a mean load of (2-10) x 10(1) cfu/ml. Although oral colonisation by C. albicans was greater than that of C. krusei, neither species induced candidal infection during this period. Subsequent immunosuppression of the rats by intramuscular cyclophosphamide (40 mg/kg body weight) initiated C. albicans infection of the dorsal tongue (around the conical papillae area) after 4 weeks, in all of three animals while similar lesions due to C. krusei were seen--albeit after 5-7 weeks--in three of eight animals. Characteristic histological changes of mucosal candidosis were discernible on the lingual mucosa of rats infected with both Candida spp. including parakeratosis, absence of a stratum granulosum, thickened rete ridges, micro-abscess formation and polymorph infiltration of the lingual epithelium. Although both species produced fungal hyphae that penetrated the epithelium up to the prickle cell layer, C. albicans hyphae tended to be relatively more profuse. Taken together these results substantiate, for the first time in an animal model, the clinical evidence that C. krusei, once considered an innocuous commensal, is capable of transforming into an invasive pathogen under conditions of immunosuppression.