Second versus first wave of covid-19 in patients with mpn

ABSTRACT

Introduction. MPN-COVID is a European LeukemiaNet cohort study, launched in March 2020 in patients with myeloproliferative neoplasms (MPN) with COVID-19. The first cohort of 175 cases was analyzed at the end of first wave (July 2020) and results provided estimates and risk factors of overall mortality (Barbui T. Leukemia, 2021), thrombosis incidence (Barbui T. Blood Cancer J, 2021), and post-COVID outcomes (Barbui T. Blood Cancer J, 2021). In the second wave of pandemic (June 2020 to June 2021), case-fatality risk in the general population has been found variable across different countries, and no information is available in MPN patients with COVID-19 diagnosed during the second wave in comparison with those of the first wave. Methods. In an electronic case report form, we registered a total of 479 cases of ET (n=161, 34%), PV (n=135, 28%), pre-PMF (n=49, 10%) and overt MF (n=134, 28%), from 39 European hematology units (Italy, Spain, Germany, France, UK, Poland, Croatia). Of these, 304 were diagnosed COVID-19 during the second wave. Results. Patients in the second wave were significantly different from those in the first wave, including parameters such as age (median 63 vs. 71 years, p<.001), sex (females 52% vs. 42%, p=0.037), MPN category (MF 24% vs. 34%, p=0.020), comorbidity (at least one comorbidity 63% vs. 74%, p=0.012), disposition (home 68% vs. 23%, regular ward 29% vs. 66%, ICU 3% vs. 11%, p<.001), need of respiratory support (28% vs. 59%, p<.001) and degree of systemic inflammation (C-Reactive Protein 51% vs. 74%, p=0.008;Neutrophil to Lymphocyte Ratio 4.1 vs. 5.4, p=0.038). In regard to COVID-19-directed therapy, in the second wave steroids were more frequently prescribed (28% vs. 40%, p=0.007), while the use of antibiotics, antivirals, hydroxychloroquine and experimental therapies was significantly less frequent (p<.001 for all the differences). Interestingly, only 4 out of 46 patients (8.7%) discontinued Ruxolitinib during second-wave acute COVID (all MF admitted to regular ward). In the two waves, distribution probability of COVID-19 incidence by Kernel method showed a substantially similar shape, whereas the two incidence peaks were associated with very different mortality, as reported in Fig. 1A. The difference between the probability of death was highly significant during the first (n=175) vs. second (n=304) 31% vs. 9% at 60 days from COVID-19 diagnosis, respectively (p<.001) (Fig. 1B). Of note, among 26 deaths, 4 (15%) occurred at home, 19 (73%) on regular wards and 3 (12%) in the ICU, and death more frequently afflicted patients with (n=17, 65%) than ET (n=5, 19%) and PV (n=4. 15%) (p<.001). Independent risk factors for death in a multivariate Cox regression model fitted on the whole cohort and adjusted for the wave to which patients belonged, were age over 70 years (HR=5.2, 95% CI 1.8-15.1, p=0.002), male sex (HR=1.9, 95% CI 1.1-3.1, p=0.016), COVID-19 severity revealed by the need for respiratory support (HR=4.5, 95% CI 1.9-10.7, p=0.001), and Ruxolitinib discontinuation (HR=3.0, 95% CI 1.3-6.9, p=0.011). Conversely, in patients who continued this drug, no risk was documented (HR=1.21, p=0.566). Taking into account death as competing event, the second outcome of interest was the incidence of thrombosis, wich occurred in a significantly lower proportion of patients in the second wave compared to the first one (n=5 [1.6%] vs. n=14 [8.0%] at +60 days, respectively, SHR=0.20, p=0.002) (Fig. 1C). All the events, but one (n=4/5) were venous and were reported in patients with ET (SHR=4.4, 95% CI 1.8-10.7, p=0.001). Conclusions. This is the largest series of MPN patients who incurred COVID-19 from June 2020 onward, namely during the 'second COVID-19 wave'. Compared to the first wave, the second one recorded a lower overall COVID-19 severity, but Ruxolitinib discontinuation still remained a risk factor for a dismal outcome. Greater vulnerability of ET than PV in developing venous thrombosis was confirmed also during the second wave. This finding suggests that ET warrants a specific antithrombo ic prophylaxis in addition to heparin.