Outcomes of Patients with Hematologic Malignancies and COVID-19: Perspective of a Large Hematology Center in Greece
Authors: Spyridis Nikolaos , Karavalakis Georgios , Mallouri Despina , Eftychidis Ioannis , Dolgyras Panagiotis , Stavroyianni Niki , Lalayanni Chrysavgi , Batsis Ioannis , Sakellari Ioanna , Anagnostopoulos Achilles , Sotiropoulos Damianos 
Published: November 2021

Abstract
The emergence of SARS-CoV-2, as of July 2021 has affected 469,042 individuals and accounted for 12,851 deaths nationally in Greece, according to WHO database. Mortality rate is higher in elderly patients (pts) and in pts with comorbidities, including malignancies. However, there is a growing interest on COVID-19 outcomes in pts with hematologic diseases. The aim of this study was to perform a systematic registration and analysis of the outcomes of pts with hematologic disease and COVID-19 in our center.
The study is a single-center, retrospective study, conducted at a Hematology Department and HCT unit of a tertiary Hospital after approval from local Ethics Committee. We included pts with a hematologic disease and RT-PCR confirmed COVID-19 infection between October 2020 and July 2021. We reviewed hematological medical records to extract demographic and clinical data of COVID-19 infections. Most of the data have already been intergraded in ASH Research Collaborative Data Hub.
Hematologic diseases were categorized to: Acute Myeloblastic Leukemia (AML), Acute Lymphoblastic Leukemia (ALL), Non-Hodgkin Lymphomas (NHL), Chronic Lymphocytic Leukemia (CLL), Hodgkin Lymphoma (HL), Multiple Myeloma (MM), Myelodysplastic Syndromes (MDS), Chronic Myeloid Leukemia (CML), Myeloproliferative Neoplasms (MPN, including all Philadelphia-negative MPN) and other hematologic conditions.
We evaluated a total of 89 pts, 54% were male and 46% female, with a median age of 64.5 (20-86) and 59.5 (21-85) years respectively. 83% of pts were ≥40 years and 27% ≥70 years old. Most of them (92%) acquired infection outside a hospital setting. 13% of pts were asymptomatic and diagnosis was confirmed only with positive RT-PCR test.
The most common represented malignancies were NHL 26%, CLL 20% and acute leukemias 13.5%, while 15% of pts underwent transplantation (HCT).
Pts presented with moderate/severe COVID-19 were 55%, while 43% of hospitalized pts required Intensive Care Unit (ICU) admission. Overall, the death rate was 24%, while remarkably almost all pts required ICU support did not survive (mortality 94%). Higher mortality observed in patients with MDS (50%), MM (43%), CLL (39%), ALL (33%) and NHL (30%).
Further analysis showed a positive correlation between mortality and male gender with 16 deaths out of 21 (p = .0245), as well as mortality and ICU admission (p &lt; .001). A chi-square test of independence was performed to examine the relation between age and COVID-19 severity, without any statistically significant result [x 2 (2, N = 87) = 3.475, p = .176]. Whereas the only significant correlation between age and mortality was among age groups 18-39 and &gt;70 years (p = .0146).
Regarding treatment, pts were divided into two subgroups, 78% of them received anticancer therapy at least once in their lives, while 22% of them have never been on treatment, mainly pts with CLL and indolent NHL. 62% of the first subgroup manifested moderate/severe COVID-19 infection requiring hospitalization with 28% death rate, while the same rates in the 2 nd subgroup were 30% and 10% respectively. Although there was a significant correlation between the treatment status and the severity of COVID-19 infection (p = .020), the above was not translated in statistically higher death rate in the first subgroup (p = .14).
There was also a correlation between HCT and COVID-19 severity in general (p = .005), with autologous HCT having statistically higher mortality than the allogeneic subgroup (p = .032). Α similar analysis in CLL and NHL groups showed no relation among treatment status, COVID-19 severity, and mortality (p values .638 and .115/ .34 and .62 respectively).
As anticipated in hematological pts, the immunocompromised nature of the underlying disease makes them extremely vulnerable to COVID-19 infection regardless of their treatment status, a fact that is also reflected in mortality despite ICU admission and support. In general, the severity of infection is correlated to anticancer therapy, while mortality to male sex, ICU admission and autologous HCT.
Larger number of pts are necessary for further studies to better understand the parameters that impact the outcome of COVID-19 in hematological pts. Hematology departments should remain COVID-19 free zones, dedicated only to hematologic treatment and pts should strictly comply with social distancing. It remains to see if vaccines can play a key role to protect this special group of pts.
Figure 1 Figure 1.

Disclosures
Anagnostopoulos: Abbvie: Other: clinical trials; Sanofi: Other: clinical trials ; Ocopeptides: Other: clinical trials ; GSK: Other: clinical trials; Incyte: Other: clinical trials ; Takeda: Other: clinical trials ; Amgen: Other: clinical trials ; Janssen: Other: clinical trials; novartis: Other: clinical trials; Celgene: Other: clinical trials; Roche: Other: clinical trials; Astellas: Other: clinical trials .