The baseline IL-6 level was 197.39 pg/mL in a 69-year-old female patient who showed high fever and dyspnea. IL-6 decreased to 9.47 pg/mL after treatment (day 8), while the symptoms were not relieved. The C-reactive protein (CRP) rebounded and procalcitonin (PCT) increased together with disease exacerbation. Follow-up chest computed tomography (CT) assessment was not performed due to poor general condition, whereas chest X-ray showed aggravated pneumonia. Follow-up sputum culture confirmed the exacerbation was caused by bacterial infection. 