Immune system function in candidiasis patients

To compare the clinical picture and the immunological characteristics, 58 candidiasis patients differing by the severity and dissemination of the disease were examined. Chronic candidiasis of the skin and mucous membranes, the most severe and disseminated form of the disease, is associated with a decrease in the number of T-lymphocytes and changes in their subpopulations, as well as high titers of Candida albicans antigen and antibodies to it in blood sera. The immune system of patients with visceral candidiasis and chronic vulvovaginal candidiasis was similar to that of healthy persons in the characteristics under study. Immediate and mixed hypersensitivity occurred in candidiasis patients more frequently than in healthy persons. In extremely severe forms of Candida infection immediate hypersensitivity prevailed.     

The C-terminal antibody binding domain of Candida albicans mp58 represents a protective epitope during candidiasis

The 58-kDa surface mannoprotein of Candida albicans (mp58) elicits strong antibody responses during infection. Epitope mapping with sera from patients with candidiasis and control individuals indicated the presence of multiple IgG-reactive continuous epitopes on the protein, expanding both the amino- and carboxy-terminal domains and several internal regions. These immunoreactive regions were similar to the ones previously identified using sera from immunized animals. Two of the epitopic regions (including the C-terminal domain) showed increased reactivity with antibodies present in sera from patients with candidiasis as compared to control individuals. Patients who survived the infection displayed increased antibody reactivity towards the C-terminal epitope as compared to those succumbing to candidiasis. A monoclonal antibody directed towards this epitopic region conferred protection in serum therapy experiments in a murine model of hematogenously disseminated candidiasis. Together, these observations indicate the carboxy-terminal antibody binding domain of C. albicans mp58 represents a protective epitope during candidiasis.     

Candida albicans fibrinogen binding mannoprotein: expression in clinical strains and immunogenicity in patients with candidiasis.

A 58 kDa cell wall-associated fibrinogen binding mannoprotein (mp58), previously characterized by our group in a Candida albicans laboratory strain (ATCC 26555), was found to be also present in the cell wall of clinical isolates of this fungus. Most strains examined appear to have functional mp58 species, as detected by their ability to bind fibrinogen. Western immunoblot analysis, with a monovalent polyclonal antibody generated against the mp58 species from strain ATCC 26555, revealed differences in recognition patterns depending on the strain tested and the culture conditions used. Serum samples from normal and Candida infected individuals were examined for the presence of antibodies against mp58 by Western immunoblotting. None of the sera from control individuals and patients suffering from superficial candidiasis contained antibodies against mp58. However, positive reactivity with this antigen and other cell wall constituents was detected for all sera from patients with confirmed systemic candidiasis. Together, these results suggest that mp58 could play an active role during infection and may be useful as a specific antigenic marker for candidiasis.     

The natural killer and fungicidal activity of the peripheral blood mononuclear cells in candidiasis

The activity of natural killers and the capacity of peripheral blood mononuclears for the extracellular killing of Candida cells in patients with different forms of candidiasis has been determined in the radiometric test with the use of targets labeled with 3H-uridine RNAase and in the fungicidal test. On the basis of the data thus obtained the conclusion has been made that in candidiasis changes in the activity of natural killers and fungicidal capacity depend on the severity of the disease and the stage of the process. Linear correlation between the activity of natural killers and fungicidal capacity in candidiasis patients at the stage of exacerbation and in healthy persons is absent.     

Clinical spectrum of invasive candidiasis in critically ill non-neutropenic patients

Invasive Candida spp. infections in non-neutropenic critically ill patients admitted to intensive care units can be classified as focal and systemic. Both types of infection usually occur after episodes of candidemia, although some focal infections may be of exogenous development, like those occurring after trauma or be device-related.The clinical spectrum of invasive Candida spp. infections includes focal urinary tract, abdominal, ocular, respiratory tract, renal and hepato-biliary infections, as well as systemic infections like candidemia and acute systemic candidiasis with multiorgan involvement after hematogenous seeding. Candida spp. isolates in "significant" samples, like synovial fluid, cerebrospinal fluid and blood cultures, represent true infection. However, the diagnosis of invasive infection based on "non-significant" samples, like surgical drains and digestive tract exudates, requires additional criteria. The total number of isolates from different sites, the presence of risk factors, the clinical host response, as well as severity of illness need to be taken into account for the diagnosis of invasive candidiasis. The clinical signs of systemic infection due to Candida spp. are completely non-specific and cannot be differentiated from bacterial peritonitis, urinary tract infection or bacteremia. These infections may be associated with signs of sepsis,severe sepsis, septic shock or multiorgan dysfunction. In the future clinical multicentre observational and interventional studies are necessary to reach agreement on clinical definitions and classification of invasive Candida spp. infections in critically ill non-immunocompromised patients.     

The 'bull's eye' pattern in hepatic tomography

Invasive fungal infections are more commonly found in patients who develop neutropenia after chemotherapy. A 4-year-old girl with diagnosis of acute lymphoid leukemia developed febrile neutropenia after chemotherapy. Broad spectrum antibiotics and antimycotic therapy were initiated. Candida albicans was isolated and Entamoeba histolytica was observed in stool examination. Chronic disseminated candidiasis had developed and was treated with amphotericin B, initially, and fluconazol. Computed tomography images were obtained that demonstrated a classic 'bull's eye' pattern; a concurrent histological study confirmed the diagnosis. Candida spp. is the major cause of opportunistic mycosis in immunosuppresed patients receiving chemotherapy for haematologic malignancies. An initial infection results in disseminated candidiasis, which persists and becomes chronic. In the 4-year-old patient, the identified risk factors consisted of a previous therapy with broad spectrum antibiotics, the gastrointestinal tract colonization with Candida albicans and prolonged neutropenia. Imaging diagnoses are made by ultrasonography, computed tomography and magnetic resonance. With ultrasound and tomography, 4 distinct patterns have been described. Pattern 1 ('wheels within wheels') and 2 ('bull's eye') are important, since they are characteristic of chronic disseminated candidiasis. The third pattern (hypoechoic image) is the most common finding with both techniques. In the current patient, patterns 2 and 3 were seen and the diagnosis was confirmed by histological study.     

Different immunofluorescent titres of Candida albicans blastospores and pseudohyphae

Indirect immunofluorescent staining ofCandida albicans pseudohyphae and blastospores by serial dilutions of sera from patients with different forms of candidiasis showed that the mycelial form fluoresced more intensely at higher serum dilutions than the blastospores.     

Microbiological non-culture methods for the diagnosis of invasive candidiasis: usefulness of surrogate markers

The usefulness of surrogate markers in the diagnosis of invasive candidiasis is based on their ability to detect the infection caused by the different Candida spp. and to differentiate when the fungus is a colonizer or it is causing an invasive disease. This differentiation has been tried by detecting antigens, antibodies and other Candida components in the patient's sera. In this paper we will review the antigens, antibodies and other Candida components which may be useful in the laboratory diagnosis of invasive candidiasis in the non-neutropenic critically ill patient.     

Modulation of neutrophil function in host defense against disseminated Candida albicans infection in mice

Neutrophils (PMNs) constitute the main mechanism of host defense against acute invasive and disseminated candidiasis. Recent studies have demonstrated that tumor necrosis factor-alpha (TNFalpha), interleukin-6 (IL-6) and granulocyte colony-stimulating factor (G-CSF) play an important role in the recruitment of PMNs at the site of invasive Candida infection. In the absence of either TNFalpha or IL-6, the course of experimental disseminated candidiasis is more severe, due to defective PMN recruitment. Treatment of mice with recombinant G-CSF (rG-CSF) leads to a significantly reduced mortality during disseminated candidiasis. The outgrowth of Candida albicans from the organs of rG-CSF-treated mice is significantly decreased. Treatment with the combination of rG-CSF and fluconazole has an additive effect on the reduction of fungal load in the organs. In subacute or chronic disseminated Candida infection, rG-CSF is less effective, indicating that neutrophil recruitment and activation are crucial in acute, life-threatening candidiasis, whereas other host defense mechanisms control the outcome of less overwhelming invasive Candida infection.     

Study of circulating immune complexes in three hematologic diseases: Acute myeloid leukemia,acute lymphatic leukemia,and hematosarcoma

Summary Circulating immune complexes (CIC) were detected by means of the polyethylen glycol (PEG) precipitation method, in the serum of untreated patients with hematologic diseases including acute myeloid leukemia (AML), acute lymphatic leukemia (ALL) and hematosarcoma (HS). Immunoglobulins (Ig) and the C ₄ fraction of complement were quantitated in the precipitate dissociated by potassium cyanate (KCNO) and in the serum. When compared to control sera, the results showed a simultaneous increase of both precipitate and Ig component. The proportion of each Ig in the precipitate was stable for the controls but variable for the patients. On the whole precipitated proteins, 30% were systematically quantitated in patients and controls. In the remaining portion were noticed Clq and C ₃ fractions of complement as well as haptoglobin and albumin. The nature of the antigen was discussed.     

Comparison of the radioimmunological and immunoenzymatic methods in detection of HBsAg]

We have compared the solid-phase radioimmunoassay(SPRIA) with a solid-phase enzyme-immunoassay (EIA) in the detection of hepatitis B surface antigen (HBsAg). 708 sera from blood donors and 500 sera from patients with various diseases (acute and chronic hepatitis, chronic renal failure in hemodialytic treatment) were tested for HBsAg with both methods. 208 sera (17,2%) were found to be positive in SPRIA and 209 sera (17,3%) in EIA. Two HBsAg positive sera were tested in dilution series with both methods, too. The results show that the sensitivity and specificity of the EIA compare very favourably with those of the SPRIA.     

慢性阻塞性肺疾病并念珠菌性口炎患者病原学及危险因素分析

目的 探讨入院慢性阻塞性肺疾病(COPD)并念珠菌性口炎患者的病原学特征以及相关危险因素.方法 采用病例研究,对2007年4月1日至2011年1月31日入院的82例COPD并念珠菌性口炎患者和82例无念珠菌性口炎COPD患者进行匹配,应用SPSS 17.0统计软件行条件logistic回归模型分析COPD患者念珠菌性口炎发生的危险因素.结果 (1)从念珠菌性口炎患者假膜培养共分离出念珠菌83株,以白念珠菌(90.4％)为最多,其次为光滑念珠菌(3.6％)、克柔念珠菌(2.4％)、热带念珠菌(2.4％)、近平滑念珠菌(1.2％);(2)统计学分析结果显示全身应用、吸入糖皮质激素是入院患者口腔念珠菌感染的独立危险因素.结论 白色念珠菌是COPD患者口腔部念珠菌感染的主要病原菌,规范使用全身糖皮质激素、正确吸入糖皮质激素是预防COPD患者口腔念珠菌感染的关键.     

The study of cell-mediated immune response in recurrent vulvovaginal candidiasis

The aim of this work was to examine in vitro the ability of cells from patients with recurrent vulvovaginal candidiasis (RVVC) to cell-mediated immune response. Peripheral blood mononuclear cells (PBMC) and whole blood cells (WBC) of 37 RVVC patients in acute infection and 14 in remission were examined for the ability to proliferation and cytokines production (IFN, TNF, IL-6). As a control, a group of 25 healthy women were examined. The cells were stimulated with Candida antigen (HKCA), LPS and PHA. To indicate the level of cytokines, the following cell-lines were used: A549 for IFN, WEHI 164 for TNF and 7TD1 for IL-6. The proliferation/death of cells was determined by colorimetric test using MTT. Distinct suppression of cell-mediated immune response (CMI) was shown in all patients comparing to the control. Greatest suppression was found in the acute phase of the disease. The ability of cells to proliferate and produce IFN increases only in remission. The data seem to suggest that in this phase of disease, the ability of cell-mediated immune response is restored. It was also indicated that IFN may take part in protection against Candida infection.     

Secreted aspartic proteases as virulence factors of Candida species

Candida infections have emerged as a significant medical problem during the last few decades. Among the different virulence traits of C. albicans, secreted proteolytic activity has been intensively investigated. Pathogenesis of the various forms of candidiasis was shown to be associated with the differential and temporal regulation of the expression of genes coding for secreted aspartic proteases (Sap). These enzymes act as cytolysins in macrophages after phagocytosis of Candida, are present in tissue penetration and are also involved in adherence to epithelial cells. Since the introduction of new antiretroviral therapeutics such as HIV protease inhibitors, oropharyngeal candidiasis is less often observed in AIDS patients. Different HIV aspartic protease inhibitors were able to inhibit the C. albicans Saps involved in adherence. The lower rates of oropharyngeal candidiasis observed in individuals receiving antiretroviral combination therapy could reflect not only an improvement in the immune system but also direct inhibition of Candida Saps by HIV protease inhibitors. Therefore, the development of specific aspartic protease inhibitors might be of interest for the inhibition of candidiasis.     

Incidence and significance of opportunistic fungi in leukemia patients in India

Twenty-four patients with acute leukemia were investigated for the incidence of opportunistic fungi. Culture isolations of the sputum and urine samples revealed significant levels of Candida in 14 patients; Candida albicans, C. tropicalis and C. pseudotropicalis were the predominant ones isolated. Aspergillus flavus was isolated from blood in two cases and C. albicans and a black yeast from the blood of another two. Serological studies showed fungal antibodies in seven patients; precipitins against Candida were detected in five and Aspergillus in two. Both of the Aspergillus positive cases and two patients who had rising antibodies against Candida died during the course of investigation. In this study 13 of 24 patients developed oral candidiasis.     

Comparison of a Newly Developed Latex Agglutination Test and an Immunodiffusion Test in the Diagnosis of Systemic Candidiasis

A newly developed latex agglutination (LA) test and a modified immunodiffusion (ID) test were evaluated. The antigen used was a homogenate of Candida albicans. A total of 167 antisera were employed in the evaluation. They included 36 sera from clinically well persons; 78 from patients with various clinical forms of candidiasis; 52 from patients with proven cases of aspergillosis, blastomycosis, coccidioidomycosis, cryptococcosis, histoplasmosis, nocardiosis, paracoccidioidomycosis, sporotrichosis, and tuberculosis; and one serum from a patient with toruloposis. Use of the LA test in conjunction with the ID test permitted the detection of more than 90% of 43 proven candidiasis cases. Of all the heterologous cases and normal human sera tested, LA reactions were noted with 3 of 10 cryptococcosis case specimens, 1 of 9 tuberculosis case specimens, and with the torulopsemia case serum. In contrast, the only heterologous serum reactive in the ID test was that from the patient with torulopsemia. Torulopsis glabrata and C. albicans antisera gave identical reactions in LA and ID tests with T. glabrata or C. albicans antigens. ID tests with selected antigens, however, permitted differentiation of rabbit and human T. glabrata antibody from that of C. albicans antibody. Six different precipitins were recognized with the C. albicans antigens. The occurrence of multiple precipitin lines and high LA titers was suggestive of severe candidiasis. The LA test, in contrast to the ID test, appeared to have prognostic value. Together, the LA and ID tests provided a simple, rapid, and accurate means of detecting and monitoring infections by species of Candida.     

The diagnostic effectiveness of an immunoenzyme test system for determining diphtheria toxin antigens in the blood serum in a clinical laboratory trial

The data on the approbation of the diagnostic value of the enzyme immunoassay (EIA) system for the determination of diphtheria toxin in the blood sera of diphtheria patients and persons suspected for diphtheria are presented. The EIA system was prepared on the basis of F(ab)2 fractions of purified antidiphtheria antibodies. 240 serum samples from diphtheria and tonsillitis patients and from healthy persons were studied. Diphtheria toxin was determined in all patients with the toxic form of diphtheria and in 41.3% of patients with its localized forms. Blood was taken mainly of the first week of the disease. In healthy persons the results of EIA were negative. Thus, the trial of the assay system in a clinical laboratory showed its good diagnostic effectiveness. The use of this EIA system in medical practice is believed to be quite promising.     

Immunoenzyme method in the diagnosis of human brucellosis

The optimum conditions for the determination of specific antibodies in the sera of brucellosis patients by means of enzyme immunoassay (EIA) have been selected. The comparative study of the specificity and sensitivity of EIA and other serological tests has demonstrated that EIA has high diagnostic effectiveness in the diagnosis of acute and chronic brucellosis. The presence of direct correlation between the results of EIA and Coombs' test is observed, which is indicative of the capacity of EIA for detecting both complete and incomplete specific antibodies. It should be pointed out that in all cases the titer of specific antibodies in EIA has been found to be 5-16 times higher than in Coombs' test, the passive hemagglutination test, and agglutination test.     

Microbiological and immunological features of oral candidiasis

Candida albicans(C. albicans) is the major infectious agent of oral candidiasis, and both innate immunity and cell-mediated immune response participate in the control of the fungal infections. The aim of this study was to correlate the clinical forms of oral candidiasis with the number of colony forming units (CFU) of C. albicans in saliva and to characterize T cell response in patients with oral candidiasis. Participants included 75 subjects: 36 with lesions of candidiasis and 39 without lesions of oral candidiasis. A 2-ml sample of saliva was collected from all subjects for microbiological analysis. Cytokine levels were determined by ELISA in supernatants of peripheral blood mononuclear cells of 25 patients with oral candidiasis, after in vitro stimulation with C. albicans antigens. In 48% of patients, no association was observed with denture use. C. albicans was detected in the saliva of 91.7% of patients with oral candidiasis, and there was an association between the number of CFU and the presence of oral lesions. A type Th1 immune response was observed in supernatants of peripheral blood mononuclear cells stimulated with C. albicans antigens. In contrast, IL-5 and IL-10 levels were very low or undetectable. Together, this study shows an association between clinical forms of oral candidiasis and the number of colonies of C. albicans in saliva, and that a systemic immune response characterized by the production of TNF-alpha and IFN-gamma is observed in patients with oral candidiasis.