Screening for cryptococcal antigenemia and analyzsis of the related cryptococcal lesions in hospitalized human immunodeficiency virus infected patients

Abstract

Objective To evaluate the prevalence of cryptococcal antigenemia and explore the related cryptococcal lesions in hospitalized human immunodeficiency virus (HIV)-infected patients. Methods Medical records of 517 HIV-infected patients, including patients' age, sex, clinical features, previous medical history, laboratory tests, chest CT, treatment and the response to treatment, in the Second Hospital of the Nanjing between January 2016 and February 2018 were retrospectively analyzed. The serum cryptococcal antigen (sCrAg) was detected by lateral flow immunoassay. The χ2 test or Fisher exact test was used to perform the statistical analysis. Results Among 517 HIV-infected cases, 51 were sCrAg positive, of whom 96.1% (49 cases) were men. The cases with CD4+ T lymphocyte count <100×106 cells/L accounted for 66.2% (342 cases), while 90.2% (46 cases) in sCrAg-positive patients showed CD4+ T lymphocyte count <100×106 cells/L with statistical significance (χ2=14.6, P<0.01). Multivariable analysis revealed that CD4+ T lymphocyte count <100 ×106 cells/L was independent risk factor for cryptococcal antigenemia (OR=4.7; 95%CI: 1.8-12.5, P<0.01). Clinical cryptococcal diseases were found in 76.4% (39/51) of patients with cryptococcal antigenemia, and cryptococcal meningitis (CM), pulmonary cyptococcosis (PC) and cryptococcal septicemia were found in 56% (28/50), 52.9% (27/51) and 44.4% (16/36) of the patients, respectively. Cryptoccal disease was not identified in 21.6% (11/51) of the patients with cryptococcal antigenemia (isolated cryptococcal antigenemia). The median (range) sCrAg titers of the patients with and without CM were 1∶1 280 (1∶10-1∶2 560) and 1: 15 (1∶2-1∶2 560), respectively (P<0.01). The proportion of CM in patients with sCrAg titers ≤1∶5, 1∶10-1∶320 and ≥1∶640 were 0 (0/10), 50% (10/20) and 90% (18/20), respectively. When cryptococcal infection was restricted to the lung, 87.5% (7/8) of the patients had sCrAg titers ≤1∶20. 30% (3/10) of the patients with sCrAg titers ≤1∶5 had PC. The median (range) sCrAg titers of the patients with cryptococcal septicemia and with isolated cryptococcal antigenemia were 1∶1 280 (1∶10-1∶2 560) and 1∶5 (1∶2-1∶320), respectively. Conclusions The prevalence of cryptococcal antigenmia is high in hospitalized HIV-infected patients. Most patients with cryptococcal antigenemia have developed cryptococcal diseases. The sCrAg titer in HIV patients may, in some extend, predicts the condition of cryptococcal infection. sCrAg titers ≥1∶640 are strongly suggestive of CM. Patients with sCrAg titers ≤1∶5 seems unlikely to have CM or cryptococcal septicemia, however, clinician should still be alarmed of possible PC. Key words: HIV; Meningitis, cryptococcal; Cryptococcal antigenemia; Pulmonary cryptococcosis; Cryptococcal septicemia