P1576: novel approaches to management of covid-19 in adult acute lymphoblastic leukemia patients

Topic: 30. Infections in hematology (incl. supportive care/therapy) Background: Despite the decline in the overall incidence of COVID-19 in the world, patients with acute lymphoblastic leukemia (ALL) remain a vulnerable group of patients. Currently, coronavirus infection has predominantly mild course of the disease. However, a positive polymerase chain reaction (PCR) test for SARS-CoV-2 may interfere with treatment of leukemia, delaying therapy and increasing the risk of ALL relapse. Aims: To identify independent variables affecting in-hospital survival, duration of hospital stay, and duration of SARS-CoV-2 persistence in patients with acute lymphoblastic leukemia and COVID-19. Methods: Between April, 2020, and December, 2022, patients with ALL and COVID-19 (30 men, 30 women) remained under observation by the hematology service of the municipal clinical hospital №52 (Moscow). In 2020 - 25 patients, in 2021 – 15 patients, in 2022 – 20 patients. 45 patients with B-ALL, 15 with T-ALL, of which 9 with Ph-positive leukemia. Remission at the time of hospitalization was observed in 28 patients, 13 patients were diagnosed with ALL relapse, and 19 patients were newly diagnosed with acute lymphoblastic leukemia during hospitalization. 45 patients were discharged, 15 died (11 patients in 2020, 4 patients in 2021). The median age was 42 years. The median duration of hospitalization was 13 days. 41 patients received chemotherapy within the month prior to COVID-19 manifestation, 23 patients received chemotherapy during hospitalization. The study endpoints were: in-hospital survival, duration of hospital stay, and duration of SARS-CoV-2 virus persistence in an oropharyngeal swab. A multivariate regression analysis was carried out, as a result of which independent variables affecting the outcome were identified. Statistical significance level of 0.05 was applied. Results: When analyzing independent variables affecting in-hospital survival, the following showed statistical significance: age over 40 years (p=0.013), Carlson comorbidity index above 4 (p=0.019), stay in the intensive care unit (p=0.04), mechanical ventilation (p= 0.001), C reactive protein (CRP) > 10 mg/l (p=0.031), lactate dehydrogenase > 400 U/L (p=0.014), class G COVID-associated antibodies < 50 U/ml at the time of outcome (p=0.001), febrile fever above 39 degrees Celsius on admission (p=0.02). When analyzing independent variables affecting the duration of hospitalization, the following showed statistical significance: agranulocytosis (p=0.047), CRP > 10 mg/l (p=0.031), class G COVID-associated antibodies < 50 U/ml at the time of outcome (p=0.042). In the analysis of independent variables affecting the duration of the SARS-CoV-2 persistence, the following showed statistical significance: ferritin level > 250 µg/l (p=0.008), lack of treatment with the virus neutralizing monoclonal antibodies (mAbs) (p=0.035). When treated with virus-neutralizing antibodies, the median of obtaining a negative test for SARS-CoV-2 was 3 days, when treated with antiviral drugs - 4 days, when transfused with anti-covid plasma from donors - 9 days. Summary/Conclusion: When analyzing independent variables affecting in-hospital survival and duration of hospitalization, in both cases, the level of increase in class G COVID-associated antibodies during hospitalization showed statistical significance. In patients with ALL, due to secondary immunodeficiency, there is a decrease in humoral immunity and, as a result, low production of antiviral antibodies. Thus, in order to reduce the period of hospitalization and the period of virus persistence, as well as to improve the overall survival of patients with ALL and COVID-19, it is expedient to carry out passive immunization with mAbs. Keywords: Acute lymphoblastic leukemia, COVID-19, Chemotherapy, Monoclonal antibody