Risk Factors for Severe Infection and Unfavorable Outcomes in Hematologic Malignancy Patients with COVID-19 Inflection during the Omicron Era: A Chinese Single-Center Retrospective Study

Purpose: The objective of this study was to evaluate the potential risk factors associated with severe infection and unfavorable outcomes among individuals with hematologic malignancies who contracted the coronavirus infectious disease (COVID-19) during the Omicron era.

Methods: This retrospective analysis included adult patients with hematologic malignancies who were diagnosed with COVID-19 during the period from November 2022 to February 2023. A comparison was made between the clinical characteristics of patients who experienced persistent COVID-19 infection or succumbed to death within 30 days and those of the remaining patients.

Results: A total of 134 patients were included in the analysis, with 23.9% (n=32) presenting as asymptomatic/mild and 29.1% (n=39) classified as severe cases. Among the patients, 54.4% (n=73) had received at least two doses of vaccines. In the subgroup of asymptomatic/mild patients, 50% had received at least three doses of vaccines, while among the severe patients, 56.4% remained unvaccinated. The multivariate analysis examining risk factors for severe infection in COVID-19 and hematologic malignancy patients identified the number of vaccine doses as an independent prognostic factor. Less than two doses of vaccines were found to be associated with severe COVID-19 infection (odds ratio [OR]: 4.213, 95% confidence interval [CI] 1.433-12.392; p=0.009). In this study, patients with persistent COVID-19 infection or succumbed to death within 30 days were categorized as the unfavorable group (n=57), while the remaining patients were classified as the favorable group (n=77). A significant difference was observed between the two groups in terms of median age (p=0.015), malignancy status (p=0.001), number of vaccine doses received (p=0.001), neutrophil count (p=0.011), immunoglobulin G levels (p=0.038), and interleukin-6 levels (p=0.025). In the multivariable analysis of risk factors for unfavorable outcomes in patients with both COVID-19 and hematologic malignancies, it was found that the number of vaccine doses and the level of immunoglobulin G were independent prognostic factors. Specifically, receiving less than two doses of vaccines (OR: 233, 95%CI 0.068-0.798; p=0.020) and having an immunoglobulin G level below 1000 (OR: 220, 95%CI 0.066-0.753; p=0.014) were associated with unfavorable outcomes.

Conclusions: Receiving multiple doses of vaccines and having higher levels of immunoglobulin G were found to improve the clinical outcome of COVID-19 in patients with hematologic malignancies.