Objectives: Patients with severe COVID-19 may be at risk of longer term sequelae. Long-term clinical, immunological, pulmonary and radiological outcomes of patients treated with anti-inflammatory drugs are lacking.

Methods: In this single-centre prospective cohort study, we assessed 90-day clinical, immunological, pulmonary and radiological outcomes of hospitalised patients with severe COVID-19 treated with tocilizumab from March 2020 to May 2020. Criteria for tocilizumab administration were oxygen saturation <93%, respiratory rate >30/min, C-reactive protein levels >75 mg/l, extensive area of ground-glass opacities or progression on computed tomography (CT). Descriptive analyses were performed using StataIC 16.

Results: Between March 2020 and May 2020, 50 (27%) of 186 hospitalised patients had severe COVID-19 and were treated with tocilizumab. Of these, 52% were hospitalised on the intensive care unit (ICU) and 12% died. Eleven (22%) patients developed at least one microbiologically confirmed super-infection, of which 91% occurred on ICU. Median duration of hospitalisation was 15 days (interquartile range [IQR] 10–24) with 24 days (IQR 14–32) in ICU patients and 10 days (IQR 7–15) in non-ICU patients. At day 90, 41 of 44 survivors (93%) were outpatients. No long-term adverse events or late-onset infections were identified after acute hospital care. High SARS-CoV-2 antibody titres were found in all but one patient, who was pretreated with rituximab. Pulmonary function tests showed no obstructive patterns, but restrictive patterns in two (5.7%) and impaired diffusion capacities for carbon monoxide in 11 (31%) of 35 patients, which predominated in prior ICU patients. Twenty-one of 35 (60%) CT-scans at day 90 showed residual abnormalities, with similar distributions between prior ICU and non-ICU patients.

Conclusions: In this cohort of severe COVID-19 patients, no tocilizumab-related long-term adverse events or late-onset infections were identified. Although chest CT abnormalities were highly prevalent at day 90, the majority of patients showed normal lung function.

Trial registration: ClinicalTrials.gov NCT04351503.