Comparing ergosterol identification by HPLC with fungal serology in human sera

Ergosterol, a predominant sterol in fungal cell membranes, holds promise as a specific marker for detecting fungal presence in human samples. This study investigated the performance of ergosterol detection compared to serological tests in identifying the presence of fungi in human sera.

Eighty-four non-duplicate human sera were analyzed by high performance liquid chromatography (HPLC) for ergosterol detection. Results were compared to serological tests for Aspergillus antigen, Candida antigen, Cryptococcus antigen, Aspergillus antibody and Candida antibody performed on the same patient sera.

Out of the 84 serum samples, 51 (60.7 %) were positive for ergosterol. Among the 33 serology-positive sera, 26 (78.8 %) were also ergosterol-positive. In contrast, 26 out of 51 (51 %) serology-negative sera (including 20 negative controls) tested negative for ergosterol. Seven out of 33 (21.2 %) serology-positive sera were ergosterol-negative, while 25 out of 51 (49 %) serology-negative sera were ergosterol-positive. Compared to serological tests, HPLC detection of ergosterol had a sensitivity of 78.8 %, specificity of 51 %, positive predictive value of 51 %, negative predictive value of 78.8 % and overall accuracy of 61.9 %.

Ergosterol detection may serve as a useful supplementary tool for identifying fungi in human sera, acting as a broad-spectrum diagnostic marker. However, further research with larger sample sizes and clinical comparisons is needed to validate these findings.