Evaluation of the clinical cutoff level of serum (1 → 3)-β-d-glucan in patients with connective tissue diseases complicated by deep fungal infections

Serum (1 → 3)-β-D-glucan levels and clinical findings were evaluated in 229 inpatients with connective tissue diseases (CTDs) during the period between June and October 2004. The mean serum (1 → 3)-β-D-glucan level was 129.7 ± 207.6 pg/mL in patients with a definitive diagnosis of fungal infections and 10.5 ± 8.6 pg/mL in patients without fungal infections. Analysis of the diagnostic sensitivity/specificity for various (1 → 3)-β-D-glucan cutoff levels gave the best results for a cutoff level of 15 pg/mL, with a sensitivity of 92.3% and specificity of 81.3%. This level was therefore determined to be the optimal cutoff in patients with CTDs.