Significant elevation of plasma cathepsin B and cystatin C in patients with community-acquired pneumonia

► To identify the plasma level of cathepsin B and cystatin C in CAP. ► A decline in the levels of cathepsin B and cystatin C after antibiotic treatment. ► Cathepsin B and cystatin C correlated with severity of CAP scores. ► They may play a role in the diagnosis and clinical assessment of CAP.