High rate of abnormal blood values and vascular complications before diagnosis of myeloproliferative neoplasms

• Vascular complications prior to diagnosis in 612 MPN patients from four centers were studied.
• Vascular complications were observed ii 25% of the patients.
• 44% had abnormal blood values at least 3 months ahead of diagnosis.
• Earlier diagnosis of MPN might make it possible to prevent complications.

BackgroundVascular complications occurring before the diagnosis of myeloproliferative neoplasms (MPN) in 612 patients from four centers in Sweden, Denmark and France were retrospectively studied.ResultsVascular complications were observed in 151 (25%) of the 612 patients. Of these, 66% occurred during the two years preceding diagnosis. The majority of events were thromboembolic (95%), and included myocardial infarction (n = 46), ischemic stroke (n = 43), transient ischemic attack (TIA) (n = 22), deep vein thrombosis/pulmonary embolism (n = 19), splanchnic vein thrombosis (n = 7), and peripheral embolism (n = 7). Bleeding was observed in only 7 (5%) of the 151 patients with vascular events (3 with intracranial bleeding, 2 with epistaxis and 2 with gastrointestinal bleeding). Full blood counts obtained at least 3 months prior to the MPN diagnosis showed that 269 (44%) had abnormal blood values, fulfilling the diagnostic criteria for MPN. During the time from the abnormal blood test to the diagnosis of MPN, 50 patients suffered from a vascular complication.ConclusionWe therefore conclude that a large proportion of MPN patients suffer severe thromboembolic complications prior to diagnosis. If MPN were diagnosed earlier, a large proportion of these events might be prevented. An MPN should always be suspected and ruled out in patients with unexplained elevated hematocrit, leukocyte and/or platelet counts.