Study objectivesThe purpose of this article is to investigate the factors associated with false negatives in cryptococcal antigen detection in patients with pulmonary cryptococcosis by studying the effects of immune status and radiology on cryptococcal antigen results. MethodsThe clinical records, serum cryptococcal antigen result, laboratory findings and computed tomography findings of 61 immunocompetent and 17 immunocompromised patients with a diagnosis based on biopsy confirmation of the presence of pulmonary cryptococcosis were reviewed during the course of the study. Chi-square test was used to analyze categorical variable. The independent t-test was obtained to analyze continuous variable. Logistic regression models was used to analyze the effects of immunity and radiology imaging on cryptococcal antigen results. ResultsWe studied the differences between these two groups. No difference were found in baseline characteristics, clinical symptoms, and laboratory findings. Logistic regression analysis showed that the significant independent variables related to serum cryptococcal antigen result were the immune status and radiology findings. ConclusionsOur study indicates that immune status and lung imaging findings are important factors influencing cryptococcal antigen detection.