Covid-19 infection in patients with hematological diseases in Brazil: Clinical characteristics and prognostic factors

ABSTRACT

Background: The COVID-19 pandemic had a high burden in Brazil. To date, data on mortality and prognostic factors of COVID-19 infection in Brazilian patients with hematological disorders are scarce. Aims: To describe the characteristics and outcomes of patients with hematological disorders admitted to the hematological COVID care unit of a reference center in Brazil;to analyze the impact of prognostic factors on in-hospital mortality. Methods: This prospective, single-center study,included 118 patients who have been admitted to the hematological COVID care unit of the Hospital das Clínicas da Faculdade de Medicina da USP, S.o Paulo, Brazil, from March to September 2020.All patients had >18 years,an underlying hematological disease and a moderate or severe COVID- 19 infection.For analyses, patients were grouped in(1)benign or no oncological treatment(n=43),(2) intensive chemotherapy,including induction protocols for acute leukemia and stem cell transplantation conditioning(n=44) or(3) intermediate chemotherapy,including lymphoma regimens,myeloma triple treatment or continuous treatment( n=31).The primary outcome was in-hospital mortality;secondary outcome was overall survival after admission in the COVID-19 unit.Univariate analysis(UVA) used odds ratio(OR) for baseline characteristics and ROC curve analysis for laboratory tests collected at admission.Multivariate analyses(MVA) were adjusted by age and hematological disease status group.The median follow-up and survival time after COVID-19-unit admission were estimated by Kaplan- Meier method.All statistical tests were two-sided;p-values<0.05 were considered significant. Results: Median age was 58(19-90) years and 55% of patients were male. Most patients(83%)had hematological malignancies,- mainly non-Hodgkin lymphoma(29%) and multiple myeloma(19%). The most frequent benign disease was sickle cell disease(5%).12 patients had undergone hematopoietic stem cell transplantation (HSCT),4 allogeneic and 8 autologous.70% had at least one comorbidity, mostly arterial hypertension and diabetes mellitus. Thromboembolic events occurred in 9%. Median hospital stay in the COVID-19 unit was 12(1-63) days;54% needed intensive care and 41% mechanical ventilation.In-hospital mortality rate was 41%[95%CI 32-50];most deaths occurred in patients with malignancies. Median follow-up was 73(95%CI 61-81) and 54(95%CI 39-66) days after admission and discharge from the COVID-19 unit, respectively.UVA showed a risk of death increased by 25% every 10 years old.The risk of in-hospital death was 3-fold and 5-fold higher in groups 2 and 3 compared with group 1.MVA showed higher risk of death in patients from group 2(OR=11.1,95% CI 2.9- 54.8) or group 3(OR=9.7,95%CI 2.4-47.5]),who had lactate dehydrogenase( LDH)>440 U/L(OR=16.8,95%CI 4.9-71.8),C-reactive protein(CRP)>100 mg/L(OR=4.1,95%CI 1.4-13.6) or platelet count<150x10e9/L(OR=3.7,95%CI 1.3-11.7), regardless of age(OR=1.2,95%CI 1.0-1.5).79% of in-hospital deaths were from COVID-19;others were mainly due to hematological disease.The overall median survival time after admission was 92 days(95% CI 34-NA) and the 75-day survival probability was 51%(95%CI 41-60).25% of patients had hospital readmission,mostly due to other infections. Summary/Conclusion: In line with other reports,patients with hematological diseases are at higher risk of mortality from COVID-19 infection, particularly in low and middle income countries.In our cohort, prognostic factors were status of disease,platelets count,LDH and CRP. These findings might help risk stratification and prioritization of vaccines in this setting.