Analysis of factors influencing SARS-CoV-2 infection and outcomes in patients with chronic lymphocytic leukemia during the burst of COVID-19 epidemic

BACKGROUND: CLL patients have immune deficiencies and are at high risk of SARS-CoV-2 infection. Limited research exists on risk factors and survival outcomes of SARS-CoV-2 infection in Asian CLL patients during the COVID-19 pandemic. Therefore, this study aims to explore the relationship between SARS-CoV-2 infection and survival in this population. METHODS: A retrospective analysis was conducted on 119 CLL patients treated at a large tertiary comprehensive hospital in western China from January 2020 to May 2023, coinciding with a surge in the epidemic in the city. RESULTS: (1) During the epidemic, the treatment group had a higher proportion of males, second-line and initial treatment, 11q- chromosome, LDH level, and lower erythrocyte count (P < 0.05). Patients in this group had longer median duration of malaise, more headaches and coughs, longer cough and sputum duration, higher rates of hyposmia, and more patients received antiviral treatment for COVID-19 and suffered weight loss. The treatment group had more CLL patients affected by SARS-CoV-2, and more patients developed secondary COVID-19 infection, and had lower RBC count and hemoglobin levels (P < 0.05). (2) Compared to the non-BTKi treatment group, more patients in BTKi treatment received treatment lasting ≥ 1 month, more had abnormal karyotyping, high-risk cytogenetics, less recent cytotoxic drug and rituximab exposure, lower lymphocyte count, elevated creatinine level, and lower glomerular filtration rate (P < 0.05). (3) Firth's penalised-likelihood logistic regression revealed that male sex increased hospitalization risk, while normal karyotyping decreased this risk. Male sex and recent rituximab exposure (within 6 months) were SARS-CoV-2 infection risk factors. Both frontline and second-or-more line therapies were associated with higher SARS-CoV-2 mortality risk compared to untreated patients (all P < 0.05). CONCLUSION: Male sex and recent exposure to rituximab within the past six months are risk factors for SARS-CoV-2 infection in CLL patients. Both frontline and second-or-more line therapies are risk factors for mortality (compared to untreated patients). Treatment with BTK inhibitors does not increase the risk of SARS-CoV-2 infection or mortality.