Candida Albicans Germ Tube Antibody Research Articles

Hacia el diagnóstico temprano de la candidiasis invasora en el paciente crítico

The management of invasive fungal infections in critically ill patients, from diagnosis to selection of the ther- apeutic protocol, is often a challenge. Early diagnosis and treatment are associated with a better prognosis, but apart from cases with positive cultures from blood or fluid/tissue biopsy, diagnosis is neither sensitive nor specific, and there is a need for specific markers in these diseases. Serodiagnostic assays such as mannan an-tigen, mannan antibodies, Candida albicans germ-tube antibodies or (1→3)-β-D-glucan detection, and mo-lecular techniques for the detection of fungal-specific DNA have been developed with promising results in critical care settings. One of the main features in diagnosis is the evaluation of risk factors for infection, which will identify patients in need of preemptive or empirical treatment. Clinical scores were built from those risk factors. The combination of prediction rules and non-culture microbiological tools could be currently be the key to improving the diagnosis and prognosis of invasive fungal infections in critically ill patients.

Clinical factors associated with a Candida albicansGerm Tube Antibody positive test in Intensive Care Unit patients

BackgroundPoor outcomes of invasive candidiasis (IC) are associated with the difficulty in establishing the microbiological diagnosis at an early stage. New scores and laboratory tests have been developed in order to make an early therapeutic intervention in an attempt to reduce the high mortality associated with invasive fungal infections. Candida albicans IFA IgG has been recently commercialized for germ tube antibody detection (CAGTA). This test provides a rapid and simple diagnosis of IC (84.4% sensitivity and 94.7% specificity). The aim of this study is to identify the patients who could be benefited by the use of CAGTA test in critical care setting.MethodsA prospective, cohort, observational multicentre study was carried out in six medical/surgical Intensive care units (ICU) of tertiary-care Spanish hospitals. Candida albicans Germ Tube Antibody test was performed twice a week if predetermined risk factors were present, and serologically demonstrated candidiasis was considered if the testing serum dilution was ≥ 1:160 in at least one sample and no other microbiological evidence of invasive candidiasis was found.ResultsFifty-three critically ill non-neutropenic patients (37.7% post surgery) were included. Twenty-two patients (41.5%) had CAGTA-positive results, none of them with positive blood culture for Candida. Neither corrected colonization index nor antifungal treatment had influence on CAGTA results. This finding could corroborate that the CAGTA may be an important biomarker to distinguish between colonization and infection in these patients. The presence of acute renal failure at the beginning of the study was more frequent in CAGTA-negative patients. Previous surgery was statistically more frequent in CAGTA-positive patients.ConclusionsThis study identified previous surgery as the principal clinical factor associated with CAGTA-positive results and emphasises the utility of this promising technique, which was not influenced by high Candida colonization or antifungal treatment. Our results suggest that detection of CAGTA may be important for the diagnosis of invasive candidiasis in surgical patients admitted in ICU.

Current diagnostic approaches to invasive candidiasis in critical care settings

For the specialist, the management of invasive candidiasis infections, from diagnosis to selection of the therapeutic protocol, is often a challenge. Although early diagnosis and treatment are associated with a better prognosis, apart from cases with positive blood cultures or fluid/tissue biopsy, diagnosis is neither sensitive nor specific, relying on many different factors, clinical and laboratory findings but there is certainly a need for the specific markers in this disease. Recently, new serodiagnostic assays as Candida albicans germ-tube antibodies or (1,3)-beta-D-glucan detection and molecular techniques for the detection of fungal-specific DNA have been developed with controversial results in critical care setting. One of the main features in diagnosis is the evaluation of risk factor for infection, which will identify patients in need of preemptive or empirical treatment. Clinical scores were built from those risk factors. For these reasons, an approach to the new diagnosis tools in the clinical mycology laboratory and an analysis of the new prediction rules and its application situations has been made. Currently, the combination of prediction rules and non-culture microbiological tools could be the clue for improving the diagnosis and prognosis of invasive fungal infections in critically ill patients.

¿Implica el aislamiento de Candida spp. en muestras intraabdominales de pacientes críticos la necesidad de tratamiento antifúngico?

The diagnostic and therapeutic approaches to IFI have changed significantly in recent years, fostered by the introduction of new diagnostic methods and new antifungal products. The diagnosis of invasive candidiasis (IC) involves both clinical and laboratory parameters, but neither of these are specific and the majority of the yeast isolated showed only colonization but not true infection. This situation occurs in critical care setting especially when surgical drainages are used. A substantial number of patients become colonized with Candida spp. after abdominal surgery, but only a minority subsequently develops invasive candidiasis. The clinical and microbiological diagnosis of Candida peritonitis remains problematic. It is still unclear which patients with may benefit from antifungal treatment. Antifungal therapy can be suggested in critically ill patients with peritonitis where Candida is diagnosed based on perioperatively sampled peritoneal fluid. Since fungal infection is also a relatively common complication of severe pancreatitis it seems reasonable that fungal prophylaxis may be an important component of management although actually there is no evidence to support this approach. However, the high mortality associated with IC is partly correlated to the difficulties of making an early diagnosis, thus, to improve earlier diagnosis and survival of IC, new nonculture-based microbiological tools such as Candida albicans germ tube antibodies (CAGTA) and/or polymerase chain reaction (PCR) techniques for the detection of fungal-specific DNA should be used in conjunction with recent published "Candida score" prediction rule. An algorithm based on this approach has been provided to assess early treatment in surgical patients with yeasts isolated from intra-abdominal samples.