The application of serum cryptococcal capsular antigen titer testing in the diagnosis of non-HIV-associated Cryptococcus neo-formans meningitis

XIAO Ke; LU Jinhui; WANG Qi

doi:10.3969/j.issn.1673-3827.2025.05.011

Abstract：Objective To investigate the use of serum cryptococcal antigen(CrAg)titer testing in diagnosing and treating non-HIV-associated Cryptococcus neoformans meningitis patients.Methods A retrospective analysis was per-formed on the clinical data of 76 non-duplicate patients with C.neoformans meningitis admitted to the Third Affiliated Hospital of Sun Yat-sen University between July 2021 and December 2022.The study aimed to investigate the relationship between the serum cryptococcal antigen(CrAg)titer of the patients and their other clinical characteristics.Results Serum CrAg titers in patients with C.neoformans meningitis patients were significantly correlated with cerebrospinal fluid CrAg titers(P<0.001).In the high titer group of serum CrAg,procalcitonin levels,cerebrospinal fluid white blood cell counts,and cerebrospinal fluid protein levels were significantly higher than those in the low titer group(P=0.001,P=0.003,P=0.015).The number of patients with increased neutrophil values in the high titer group and the number of pa-tients with decreased cerebrospinal fluid glucose levels were also significantly higher than those in the low titer group(P=0.005,P=0.049).The presence of headache as a symptom also differed significantly among different serum CrAg titer groups(P=0.019).The positive rates of India ink staining and meningeal irritation signs were significantly higher in the high titer group of serum CrAg than in the low titer group.Conclusion Serum CrAg titers exhibited a strong association with various clinical characteristics in patients with C.neoformans meningitis.Therefore,it can serve as a valuable tool for diagnosing,treating,and monitoring the prognosis of these patients,particularly those with lumbar puncture contrain-dications.