Introduction and objective:
Patients with lymphoid malignancies, were found to have a higher risk of SARS-CoV-2 infection and a severe course of COVID-19. Real-world data (RWD) is presented on the clinical course of COVID-19 in patients with lymphoid malignancies from the centres of the Polish Adult Leukemia Group (PALG).

Material and methods:
A retrospective analysis was carried between October 2023 – February 2024 of patients diagnosed with COVID-19.

Results:
Antiviral treatment of COVID-19 was used in 72.9% of patients (51.8% nirmatrelvir+ritonavir, 9.4% remdesivir, 11.8% molnupiravir; the remaining patients were treated symptomatically. The hospitalization rate was 72.9%, but most patients presented with mild symptoms or asymptomatic COVID-19. Only 7.1% of patients required hospitalization in the Intensive Care Unit (ICU) and mechanical ventilation. The median hospitalization time was 10.0 days (IQR 15.0). A significant correlation was found between the length of hospitalization and the severity of COVID-19 course, assessed according to the AOTMiT scale, performance status according to the ECOG scale, number of previous COVID-19 episodes, use of antibiotic therapy, highest detected CRP and HCT (p < 0.05). On median, positive COVID-19 test result lasted 8.0 days (IQR 11.0), and the only risk factor for longer duration of COVID-19 test positivity was the absolute number and percentage of monocytes (p<0.05).

Conclusions:
Analysis showed that the clinical course of COVID-19 was mild in the majority of patients. Regarding the changes in the clinical course of COVID-19 over time, further studies are necessary to isolate the risk factors risk of severe infection.