The role of 1,3-beta D-glucan, mannan antigen and anti-mannan IgG antigen in the early diagnosis of patients with candidemia

Introduction and Objective: Candidemia is an infectious disease that requires early and accurate diagnosis, effective treatment has vital importance and can be fatal. The gold standard method in diagnosis is blood culture, but it may delay the initiation of an effective treatment due to its low sensitivity and resulting period. Therefore, rapid diagnostic tests other than culture are needed. The hypothesis of our study is based on the idea that serologic tests for mannan antigen, beta D-glucan and anti-mannan IgG antibody can accurately and rapidly diagnose candidemia and start appropriate treatment earlier. In our study, we aimed to investigate the effectiveness of mannan antigen, beta D-glucan and anti-mannan IgG antibody in the early and accurate diagnosis of candidemia and to reveal their contribution to clinical practice. Materials and Methods: Between September 2024 and February 2025, 34 candidemia patients aged 18 years and older who were hospitalised in the intensive care unit (ICU) and inpatient clinics at Bezmialem Vakif University Faculty of Medicine Hospital, 27 bacteraemia patients and 27 healthy volunteers were examined as the control group. Mannan antigen, beta D-glucan and anti-mannan IgG antibody levels were measured by ELISA in serum samples obtained from patients in the study and control groups. Results: When candidemia and non candidemia cases were compared, a statistically significant difference was found for mannan antigen and anti-mannan IgG levels (p<0.001, p<0.001, respectively), while no significant difference was found for beta D-glucan level (p=0.17). Sensitivity was increased in all combinations of tests and was statistically significant (p<0.001 for all). The triple combination of MN Ag, MN Ab and BDG tests had the highest diagnostic performance. When a single biomarker was used, MN Ag had the best performance and BDG had the worst performance. Conclusion: In our study, it was observed that mannan antigen and anti-mannan IgG antibody had a guiding potential in the early diagnosis of candidemia, while the diagnostic performance of BDG was insufficient. In addition, the combined use of biomarkers significantly increased the diagnostic performance. Key words: Candidemia, mannan antigen, anti-mannan antibody, beta D-glucan