Evaluation of different commercial ELISA methods for the serodiagnosis of systemic candidosis

Relationship Between the Quantity of Oral Candida and Systemic Condition/Diseases of the Host: Oral Candida Increases with Advancing Age and Anemia

BACKGROUND

The impact of host systemic conditions/diseases on the prosperity of oral Candida colonies remains unclear. The aim of the present study was to investigate whether a relationship exists between the quantity of oral Candida and the systemic condition/diseases of the host.

PATIENTS AND METHODS

The cross-sectional relationship between Candida mannan concentrations and health check-up results was analyzed in consideration of local conditions that influence the prevalence of oral Candida.

RESULTS

Candida mannan concentrations correlated with age, the number of untreated decayed teeth, number of prosthetic teeth, salivary pH, HbA1c, and the red blood cell count in a univariate analysis. In a multivariate analysis, Candida mannan concentrations correlated with age, the number of untreated decayed teeth, number of prosthetic teeth, salivary pH, and the red blood cell count. Candida mannan concentrations were higher in subjects older than 80 years, with a higher number of either untreated or prosthetic teeth, with a lower salivary pH, and with a decreased red blood cell count. Mannan concentrations were slightly higher in subjects with elevated HbA1c.

CONCLUSIONS

The present results suggest a close relationship between the quantity of oral Candida and the systemic condition/diseases of the host. Oral Candida may increase in immunocompromised hosts.

Application of Culture-Independent Rapid Diagnostic Tests in the Management of Invasive Candidiasis and Cryptococcosis

The diagnosis of invasive candidiasis (IC) and cryptococcosis is often complicated by slow and insensitive culture-based methods. Such delay results in poor outcomes due to the lack of timely therapeutic interventions. Advances in serological, biochemical, molecular and proteomic approaches have made a favorable impact on this process, improving the timeliness and accuracy of diagnosis with resultant improvements in outcome. This paper will serve as an overview of recent developments in the diagnostic approaches to infections due to these important yeast-fungi.

Invasive candidiasis serological diagnosis in solid organ transplant recipients

Solid organ transplant recipients are at high risk of fungal infections, because of ongoing immunosuppressive treatment. There are three post organ transplant phases: early, intermediate, and late, all of them at risk of Candida infections. Since conventional tests are insufficient, specific secondary diagnostic tests are still being explored. Serological tests are currently the most common choice. The present study was to determine the usefulness of mannan antigen and anti-mannan antibody detection in diagnosing invasive candidiasis in liver or kidney transplant recipients. The levels of mannan and anti-mannan antibodies were assessed with Platelia Candida Ag Plus, and Platelia Candida Ab Plus (Biorad, Marne-la-Coquette, France) commercial tests, according to manufacturer's guidelines. Sixty six serum samples were obtained from 25 patients (9 liver transplant recipients, 7 kidney transplant recipients, and 9 patients prepared for a kidney transplant), 29 serum samples from 15 patients tested positive for mannan antigen. Serum samples were obtained from 14 patients tested positive for anti- mannan antibodies. Fungal antigen detection in blood serum in patients under immunosuppression, especially with neutropenia, suggests that antifungal treatment should be administered. Serological tests, especially mannan and anti-mannan ones, are very useful for confirmation or exclusion of invasive candidiasis in high-risk patients.

Invasive fungal infections in patients with cancer in the Intensive Care Unit

Invasive fungal infections (IFIs) have emerged as a major cause of morbidity and mortality amongst critically ill patients. Cancer patients admitted to the Intensive Care Unit (ICU) have multiple risk factors for IFIs. The vast majority of IFIs in the ICU are due to Candida spp. The incidence of invasive candidiasis (IC) has increased over recent decades, especially in the ICU. A shift in the distribution of Candida spp. from Candida albicans to non-albicans Candida spp. has been observed both in ICUs and oncology units in the last two decades. Timely diagnosis of IC remains a challenge despite the introduction of new microbiology techniques. Delayed initiation of antifungal therapy is associated with increased mortality. Therefore, prediction rules have been developed and validated prospectively in order to identify those ICU patients at high risk for IC and likely to benefit from early treatment. These rules, however, have not been validated in cancer patients. Similarly, major clinical studies on the efficacy of newer antifungals typically do not include cancer patients. Despite the introduction of more potent and less toxic antifungals, mortality from IFIs amongst cancer patients remains high. In recent years, aspergillosis and mucormycosis have also emerged as significant causes of morbidity and mortality amongst ICU patients with haematological cancer.

The use of mannan antigen and anti-mannan antibodies in the diagnosis of invasive candidiasis: recommendations from the Third European Conference on Infections in Leukemia

Introduction

Timely diagnosis of invasive candidiasis (IC) remains difficult as the clinical presentation is not specific and blood cultures lack sensitivity and need a long incubation time. Thus, non-culture-based methods for diagnosing IC have been developed. Mannan antigen (Mn) and anti-mannan antibodies (A-Mn) are present in patients with IC. On behalf of the Third European Conference on Infections in Leukemia, the performance of these tests was analysed and reviewed.

Methods

The literature was searched for studies using the commercially available sandwich enzyme-linked immunosorbent assays (Platelia™, Bio-Rad Laboratories, Marnes-la-Coquette, France) for detecting Mn and A-Mn in serum. The target condition of this review was IC defined according to 2008 European Organization for Research and Treatment of Cancer/Mycoses Study Group criteria. Sensitivity, specificity and diagnostic odds ratios (DOR) were calculated for Mn, A-Mn and combined Mn/A-Mn testing.

Results

Overall, 14 studies that comprised 453 patients and 767 controls were reviewed. The patient populations included in the studies were mainly haematological and cancer cases in seven studies and mainly intensive care unit and surgery cases in the other seven studies. All studies but one were retrospective in design. Mn sensitivity was 58% (95% confidence interval [CI], 53-62); specificity, 93% (95% CI, 91-94) and DOR, 18 (95% CI 12-28). A-Mn sensitivity was 59% (95% CI, 54-65); specificity, 83% (95% CI, 79-97) and DOR, 12 (95% CI 7-21). Combined Mn/A-Mn sensitivity was 83% (95% CI, 79-87); specificity, 86% (95% CI, 82-90) and DOR, 58 (95% CI 27-122). Significant heterogeneity of the studies was detected. The sensitivity of both Mn and A-Mn varied for different Candida species, and it was the highest for C. albicans, followed by C. glabrata and C. tropicalis. In 73% of 45 patients with candidemia, at least one of the serological tests was positive before the culture results, with mean time advantage being 6 days for Mn and 7 days for A-Mn. In 21 patients with hepatosplenic IC, 18 (86%) had Mn or A-Mn positive test results at a median of 16 days before radiological detection of liver or spleen lesions.

Conclusions

Mn and A-Mn are useful for diagnosis of IC. The performance of combined Mn/A-Mn testing is superior to either Mn or A-Mn testing.

Syscan3, a kit for detection of anti-Candida antibodies for diagnosis of invasive candidiasis

Sera from 76 immunocompetent and 293 immunocompromised subjects were assayed for anti-Candida antibodies. The sensitivity, specificity, positive predictive value, and negative predictive value for invasive candidiasis were 74%, 75%, 62%, and 84% in the immunocompetent group and 15%, 60%, 1.7%, and 93% in the immunocompromised group, respectively. Syscan3 has high negative predictive value.