Figure 1

Receiver operating characteristic curve. Based on a receiver operating characteristic curve, the cut-off level of heat shock protein (HSP) 47 that resulted in the highest diagnostic accuracy for drug-induced lung diseases (DILD) with a diffuse alveolar damage (DAD) pattern was 1711.5 pg/mL. This value discriminated between the DAD group and the other groups with 87.5% sensitivity and 97.4% specificity and was associated with a diagnostic accuracy of 95.7%. Use of serum HSP47 levels for diagnosis of DILD with a DAD pattern resulted in the largest area under the curve (0.929) when compared with the use of serum Krebs von den Lungen-6 (KL-6), surfactant protein (SP)-A, and SP-D levels (0.367, 0.677, and 0.468, respectively).