Background and purpose: Cryptococcus neoformans is an encapsulated pathogenic yeast that causes a wide range of clinical manifestations. The serum cryptococcal latex agglutination test is a simple, rapid, and reliable diagnostic test for cryptococcosis. This study was performed to assess the clinical relevance of serum cryptococcal antigen (CRAG) titer in patients with cryptococcosis with or without human immunodeficiency virus (HIV).
Methods: From January 1999 to December 2007, 45 patients with a diagnosis of cryptococcosis made by culture and/or histopathology were enrolled in this retrospective study. Ten patients had HIV and 35 were not infected.
Results: Patients with HIV were more likely to have central nervous system (CNS) involvement than patients without HIV (100% vs 37.1%; p = 0.0005), higher serum CRAG titers (median, 1:1024 vs 1:64; p < 0.05), higher positive cerebrospinal fluid (CSF) CRAG (100% vs 37.1%; p = 0.0005), and higher CRAG titers in the CSF (median, 1:1024 vs 1:32; p < 0.001). Patients without HIV were more likely to have pulmonary involvement (62.9% vs 0%; p = 0.0005) and no underlying disease at diagnosis (42.9% vs 0%; p = 0.011). Serum CRAG titers among patients without HIV with CNS or pulmonary cryptococcosis declined during treatment and no relapse was noted when serum CRAG titers were <or=1:8 at the end of treatment.
Conclusions: Serum CRAG titer can be used to monitor disease activity during treatment for CNS and pulmonary cryptococcosis in patients without HIV.