Objective: To evaluate the usefulness of serum galactomannan (GM) for the diagnosis of invasive pulmonary aspergillosis (IPA) in critically ill patients.
Methods: Study was conducted between February 2007 and July 2008. Included patients on admission ICU who suffer from suspected IPA. GM test and culture were collected 2 weekly. Clinical feature, mycological evidence and optical density index (ODI) were noted. Clinically invasive fungal infection (IFI) were defined proven, probable and possible. The patients were classified into neutropenia, non-neutropenia and treated with immunosuppressive agents, non-neutropenia and non-immunosuppressive agents. To compared of the sensitivity and specificity of GM in different patients.
Results: 94 patients were included, 4 patients were proven, 29 patients were probable, 34 patients were possible IFI, 27 patients were non-IPA. The positive rate of the GM was 31.9% (30/94). The sensitivity and specificity of GM in proven cases and probable cases are 66.7% and 92.6%. GM assay tended to become positive earlier than the culture 2 - 10 (5.33 +/- 2.17) d. We found that differences in patient diagnosis and selection might account for the disparities seen for positive rate for the GM test. There was positive in three of the four patients with proven, the positive rate of GM was 65.5% for probable cases, for possible cases was 17.6%, for non-IPA cases was 7.4% (P = 0.001). For patient with neutropenia, treated with immunosuppressive agents and without immunosuppressive agents, the positive rate of GM was 52.9% vs 41.7% vs 34.6% (P = 0.015); the sensitivity was 80.0% vs 70.0% vs 53.8% (P = 0.011), the ODI was 1.365 (0.582 - 6.736) vs 1.123 (0.623 - 6.868) vs 0.554 (0.522 - 0.823), P = 0.005, respectively.
Conclusion: These results show that GM test is useful for early diagnosis IPA in critically ill patients. Differences in patient selection and diagnosis might account for the disparities seen for positive rate and sensitivity for the GM test. It has been higher sensitivity and ODI in the patient treated by immunosuppressive agents.