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Diagnosis of invasive fungal disease (IFD) in patients under intensive care is challenging. Circulating biomarkers, (1,3)-β-D-glucan (BG) and galactomannan (GM), were prospectively assessed in 98 critically ill patients at risk of IFD. There were 11 cases of invasive aspergillosis (IA; 4 proven and 7 probable), 9 cases of proven invasive candidiasis (IC), 1 case of mixed proven IC and probable IA, 1 case of proven zygomycosis, and 1 case of mixed mycelial proven IFD. In all IA cases there was no significant difference when the area under the receiver operating characteristic curve (AUC) of GM (0.873 [95%CI, 0.75-0.99]) and BG (0.856 [95% CI, 0.71-0.99]) were compared (p = 0.871). The AUC for BG in IC and for the rest of the IFD cases was 0.605 (95% CI, 0.39-0.82) and 0.768 (95% CI, 0.63-0.90) respectively. Positive BG (40%) predated blood culture (n = 3) and abdominal pus (n = 1) a mean of 3.25 days before Candida was grown. In patients with IFD caused by molds, BG appeared a mean of 5.65 days before culture results. For the diagnosis of patients at risk of IC, BG has shown a high NPV (94.5%), with positive results also predating blood cultures in 30% of patients. In conclusion, early BG results permit a timely initiation of antifungal therapy in patients at risk of IFD.

Background The diagnosis of invasive candidiasis is difficult because there are no specific clinical manifestations of the disease and colonization and infection are difficult to distinguish. In the last decade, much effort has been made to develop reliable tests for rapid diagnosis of invasive candidiasis, but none of them have found widespread clinical use. Results Antibodies against a recombinant N-terminal fragment of the Candida albicans germ tube-specific antigen hyphal wall protein 1 (Hwp1) generated in Escherichia coli were detected by both immunoblotting and ELISA tests in a group of 36 hematological or Intensive Care Unit patients with invasive candidiasis and in a group of 45 control patients at high risk for the mycosis who did not have clinical or microbiological data to document invasive candidiasis. Results were compared with an immunofluorescence test to detect antibodies to C. albicans germ tubes (CAGT). The sensitivity, specificity, positive and negative predictive values of a diagnostic test based on the detection of antibodies against the N-terminal fragment of Hwp1 by immunoblotting were 27.8 %, 95.6 %, 83.3 % and 62.3 %, respectively. Detection of antibodies to the N-terminal fragment of Hwp1 by ELISA increased the sensitivity (88.9 %) and the negative predictive value (90.2 %) but slightly decreased the specificity (82.6 %) and positive predictive values (80 %). The kinetics of antibody response to the N-terminal fragment of Hwp1 by ELISA was very similar to that observed by detecting antibodies to CAGT. Conclusion An ELISA test to detect antibodies against a recombinant N-terminal fragment of the C. albicans germ tube cell wall antigen Hwp1 allows the diagnosis of invasive candidiasis with similar results to those obtained by detecting antibodies to CAGT but without the need of treating the sera to adsorb the antibodies against the cell wall surface of the blastospore.