A clinical study of cryptococcal meningitis--sequential changes of cryptococcal antigen titers

Abstract

We reviewed the clinical manifestations, sequential changes in cryptococcal antigen titers in serum and cerebrospinal fluid (CSF), and the antifungal drug susceptibility of Cryptococcus neoformans in three patients with cryptococcal meningitis between 1996 and 2000. Cryptococcal antigen titers were measured using the latex agglutination method with Pastrex Cryptococcus (Fuji Mebio, Tokyo) and Serodirect Cryptococcus (Eiken Chemical, Tokyo). The underlying systemic diseases in the three patients were liver cirrhosis, non-Hodgkin's lymphoma associated with miliary tuberculosis, and malignant thymoma associated with systemic lupus erythymatosus. The CSF samples showed positive indian ink staining in two of the three patients and C. neoformans was cultured from all three. The cryptococcal antigen titers in serum were higher than those in the CSF. The serum and CSF cryptococcal antigen titers measured by Serodirect Cryptococcus were higher than those measured by Pastrex Cryptococcus. The maximum titers of antigen in serum and CSF measured by Serodirect Cryptococcus were greater than 1,024 in all three patients. The treatment regimens used for the three patients were amphotericin-B (AMPH-B) and flucytosine (5-FC), fluconazole (FLCZ) and intrathecal AMPH-B, FLCZ and 5-FC, and intrathecal AMPH-B, respectively. The antigen titers in serum and CSF decreased after treatment in all three patients. The antigen titers decreased slowly over 7.3 months in the most seriously ill patient who had non-Hodgkin's lymphoma associated with miliary tuberculosis. The time between the beginning of treatment and CSF cryptococal antigen titers falling to less than 8 was 1.7 to 7.3 months in the three patients, but the serum titers did not decrease to less than 8 during this period. The minimum inhibitory concentration was 0.06-0.25 microgram/ml for AMPH-B, 4-8 micrograms/ml for 5-FC, 2-8 micrograms/ml for FLCZ, 0.125-0.5 microgram/ml for miconazole and 0.03-0.125 microgram/ml for itraconazole. The measurement of sequential changes in cryptococcal antigen titers in serum and CSF was useful for evaluating the response to treatment.