The classic myeloproliferative neoplasias (MNP), including polycythemia vera (PV), essential thrombocythemia (ET), primary myelofibrosis (PMF) or secondary to PV or ET, are among the most frequent of malignant hemopathies, with overall prevalence estimated at around 10,000 patients followed in France. Due to the median age of patients around 65, the frequency of cardiovascular complications of these thrombogenic diseases and the impact of cytoreductive treatments on immune cells, these patients are considered to be at risk of developing forms severe of COVID-19. This study will assess the impact of MNPs on the risk of developing a severe form of COVID-19, identify new risk factors linked to the disease as well as the impact of treatments for MNPs according to their pharmacological class.

It is a descriptive, prospective epidemiological study using retrospective patient data, multicenter, non-interventional, carried out in FIM (French Intergroup of Myeloproliferative syndromes) / FILO (French Innovative Leukemia Organization) centers.

This is an exploratory descriptive study in order to put in place as soon as possible a possible strategy for the protection of patients most at risk.

The study will include all consecutive patients with MNP according to the WHO (World Health Organization) classification seen in consultation or teleconsultation over the duration of the study, whether or not they have had a COVID-19 infection.

The collection of clinical data, treatment regimens and survival and death data will be carried out by the investigator or a member of his medical team, after delivering an information note to the patient informing him of the computerized processing of his data, subject to the patient's non-objection.

The diagnosis of asymptomatic COVID 19 will be made on the presence of a positive serology and on the absence of clinical signs on questioning.

The presence of a symptomatic COVID 19 infection will be posed on the presence of clinical signs +/- CT as identified by the practitioner who treated the patient and confirmed or not by a positive PCR and / or a positive serology.

Data collected:

• Socio-demographic data (gender, date of birth)
• Description of hemopathy and its treatment
• Description of COVID-19 infection and its management
• Biological data: blood count, specific COVID-19 test results if available (PCR, serology).
• History, comorbidities
• Evolution of COVID-19 infection and possible specific treatment

Inclusion Criteria:

• Patient with PV, ET, PMF or MF secondary to PV or ET diagnosed before the COVID-19 pandemic
• Seen in consultation or teleconsultation from May 2020 or deceased if the investigator became aware of this death during the study period

Exclusion Criteria:

• Refusal to participate in the study

Patients with Classic myeloproliferative neoplasias (MPN), including polycythemia vera (PV), essential thrombocythemia (ET), primary myelofibrosis (PMF) or secondary to PV or ET, and infected by COVID-19