Associations of Serum Cryptococcal Antigen with Different of Clinical Characteristics: a Comprehensive Analysis of 378 Pulmonary Cryptococcosis Patients

Background: Pulmonary cryptococcosis (PC) is an infection typically diagnosed in immunocompromised or immunocompetent patients, which can lead to severe disease if not treated appropriately. We aimed to determine the association between clinical manifestations, computed tomography (CT) findings, and host immune status with the serum cryptococcal antigen (CRAG) test results of PC patients.

Methods: The clinical data of 378 PC patients over a 12-year period were retrospectively reviewed at Shanghai Pulmonary Hospital (Shanghai, China). Serum CRAG was detected by a latex agglutination (LA) test using CryptoTrol (Immuno-Mycologics Inc., Norman, OK, USA). Patients were categorized according to their serum LA results, and their clinical characteristics were analyzed: 244 of 378 patients showed positive serum LA results and 134 had negative results.

Results: Immunocompromised hosts (ICH) were more likely to present positive LA results. The ICH group had higher titers of LA test than the non-immunocompromised host (NICH) group. Patients with negative LA results often had no symptoms and their CT findings presented a solitary nodule or mass, while LA-positive patients had variable symptoms such as cough, expectoration, fever, etc. A large diversity of CT manifestations were observed in the LA-positive patients, such as multiple nodules, patchy shadows, interstitial infiltrates, and diffuse granular shadows. Patients with a solitary nodule or mass had lower titers than did the patients with other manifestations. The clinical characteristics of LA-positive patients were different from those of LA-negative patients.

Conclusions: Serum CRAG test results were found to be associated with the clinical manifestations, CT findings, and host immune status of PC patients.