Pulmonary cryptococcosis: Clinical, radiographical and serological markers of dissemination

Background and objective: This study aimed to identify markers of disseminated infection in patients presenting with pulmonary cryptococcosis. Methods: Patients diagnosed with pulmonary cryptococcosis at a tertiary hospital between April 1998 and April 2005 were included and their clinical, radiological and pathological data analysed retrospectively. Results: Thirty-one patients (14 male) were recruited into the study. Disseminated infection was seen in nine patients (29%), with the isolation of Cryptococcus neoformans from the blood of five patients and the cerebrospinal fluid of seven (three patients had both positive blood and cerebrospinal fluid findings). Patients with disseminated infection had a significantly higher incidence of impaired cellular immunity (immunosuppressant use, AIDS and haematological malignancy) (P = 0.015), fever (P < 0.001), interstitial abnormalities on CXR (P < 0.001), pleural effusion (P = 0.017) and death (P = 0.04) when compared with patients with localized infection. Serum cryptococcal antigen (sCRAG) was positive in 17 of the 19 patients tested at the time of diagnosis. Significantly higher sCRAG titres were noted in patients who had fever (P = 0.001), interstitial abnormalities on CXR (P = 0.004), pleural effusion (P = 0.018), disseminated disease (P = 0.003) and in those who died (P = 0.05). Conclusions: In pulmonary cryptococcosis patients, the presence of fever, interstitial abnormalities on CXR or pleural effusion should lead clinicians to suspect disseminated infection. High titres of sCRAG may indicate more extensive extra-pulmonary involvement and a worse prognosis.