Introduction. Clinical severity of COVID-19 and treatment failure are augmented in immunocompromised patients. Several concomitant diseases and immunosuppressant therapies show a different weight in influencing the outcomes of SARS-CoV-2 infection. 

Aim. The aim of this report is to describe the timelapse of COVID-19 in immunocompromised patients, including the clinical severity, the viral load persistence, and the outcome of the infection.

Methods. 40 immunocompromised patients were observed after resulting positive for SARS-CoV-2 tested by RT-PCR on nasopharyngeal swab. We performed blood gas analysis (BGA) and high-resolution computed tomography (HRCT) of the chest to assess clinical severity of the disease. Patients were followed up to 12 months.

Results. 24/40 (60%) were females. Median age was 54 years. 15 patients were affected by non-Hodgkin lymphoma (NHL), 4 affected by Hodgkin lymphoma (HL), 6 chronic lymphocytic leukemia, 12 patients received immunosuppressant for solid organ transplant, 3 showed primitive immunodeficiency.

After treatment, 28 patients (70%) had a clinical resolution with good improvement of BGA and HRCT. 12 patients worsened (5 of them underwent invasive mechanical ventilation) and did not survive (30%). Of the 12 clinically healthy subjects, 9 patients affected by NHL (60%) showed a viral load persistence, with a median positivity of 160 days. These patients showed multiple clinical relapses of COVID-19 with subsequent acute episodes of respiratory failure, hospital admission and were treated with newly approved drugs.

Conclusion. Immunocompromised patients can show a persistent viral load and present clinical relapse of COVID-19 with current drug protocols