Infection by sars-cov-2 in hematologic patients: An unicentric retrospective study

ABSTRACT

Background: The coronavirus disease 2019 (COVID-19) pandemic has imposed several constrains in the medical practice, especially in hematologic patients (pts) where a higher mortality rate is expected. In our center strict measures were implemented earlier, with the use of personal protective equipment, hand wash at all times, internal separated circuits, frequent prophylactic tests, teleconsultation and rapid isolation of positive cases. However, data is still limited and risk factors for increased susceptibility remain unclear. Aims: Characterize our pts with COVID-19 regarding the type of hematologic disease, the respective treatment, infection severity and identification of any possible risk factors that may have impact in the outcome. Methods: Pts with a positive quantitative RT-PCR from nasopharyngeal swab between 18/03/2020 and 02/02/2021 were identified. Epidemiologic, laboratory, and clinical characteristics were retrospectively collected. Chi-square and Mann-Whitney-U tests were performed to identify statistical differences between groups and logistic binary regression to assess predictive risk factors. Severity of illness was defined by level of care [ambulatory, general inpatient wards and intensive care unit (ICU)], need for respiratory support, incidence of thrombotic events, acute kidney injury and/or death. Active hematologic treatment was defined as therapy within 6 months of COVID-19 diagnosis. Results: A total of 81 pts were identified, with a median age of 61 years (19-88), 52% were male, 63% had an ECOG PS 0 and 69% had at least one comorbidity (hypertension 36%, dyslipidemia 21%, cardiovascular disease 21%, diabetes mellitus 14% and pulmonary disease 11%). Regarding the hematologic disease, 83% had a neoplastic malignancy (non-Hodgkin lymphoma 30%, myeloproliferative neoplasms 16%, acute myeloid leukemia 11% and multiple myeloma 11%), 64% were in active treatment and 43% had active disease. Concerning the COVID-19 infection, 46% required hospital admission among which 65% needed respiratory support and 9% admitted to an ICU. Median overall survival (OS) was not reached (84% at 1 month) and the mortality rate was 17%, mainly in pts with active disease and neoplastic malignancy. Non-survival pts had a lower hemoglobin level (8,3g/dL vs 12g/dL;p-value 0,016), a higher CRP (218mg/L vs 22mg/L;p-value 0,041), acute renal failure (36% vs 6%;p-value 0,014), more need of respiratory support (71% vs 27%;p-value 0,004) and mechanical ventilation (21% vs 5%;p-value 0,022). There were no statistical differences regarding age, absolute lymphocyte count, platelet count and LDH. Regression analysis revealed hemoglobin level (p-value 0,026), CRP (p-value 0,05) and respiratory support (p-value 0,003) as predictive factors for death. In our pts there were no thrombotic events. Summary/Conclusion: Nearly half of the pts were admitted to the hospital and discharged. In our analysis low hemoglobin level, high CRP and respiratory support were associated with poorer survival, however, given our small sample, these findings need to be confirmed. Contrary to most of the published results, the number of confirmed COVID-19 positive cases was surprisingly low, with only 81 cases in 11 months, with a mortality rate similar to the general population and lower than expected. We believe that implementing early and rigorous protective measures as well as create self-awareness may be the key to improve mortality rate in this highly susceptible population.