According to findings from a recent study, increased risk of recurrent blood clots and progression of thrombosis were present among patients with non-proliferative complete blood count (CBC) thrombosis myeloproliferative neoplasms (MPN), driver mutations, and non-splanchnic involvement compared with patients with splanchnic involvement. 

Yannick LE Bris, PhD, PharmD, CHU Nantes, Nantes, France, presented data from this study at the 2022 ASH Annual Meeting and Exposition in New Orleans, LA. 

“Thrombosis is the main cause of morbidity in myeloproliferative neoplasms (MPN) and can be the mode of the revelation of these malignant diseases,” Dr. Bris et al wrote. 

An atypical thrombotic event warrants the search for MPN-related mutations, even in non-proliferative features on the CBC, particularly in cases of splanchnic cerebral thrombosis. This study aimed to observe patients with an arterial or venous thrombotic event possibly leading to MPN, without signs of myeloproliferation in CBC. 

Between May 2019 and June 2022, 216 patients with a median age of 55 years were studied at 31 centers in France and Switzerland. Inaugural thrombosis was venous (80%) or arterial (20%), with splanchnic involvement being the most common location (50%). Patients had a driver mutation of JAK2V617F, CALR, MPL, or just spontaneous progenitor growth. 

At 3 months, a clinical follow-up was available in 197 patients, with a median follow-up time of 61 months. 42 patients experienced recurrent thrombosis, with a median time to recurrence being 37 months. Recurrence occurred more frequently in patients with non-splanchnic thrombosis than splanchnic thrombosis (30% vs. 13% p=0.004) and did not differ between patients with or without MPN criteria (18% vs. 30% p=0.1). 

Hematological progression was present in 27 patients at a median time to progression of 31 months since thrombosis. Progression-free survival (PFS) was significantly reduced in patients with non-splanchnic thrombosis (86% vs 97% at 31 months p<0.0001). 

“Thrombosis cases with a non-proliferative CBC but with MPN driver mutations leading to MPN suspicion constitute a heterogeneous group of patients, with many cases of non-splanchnic involvement,” Dr. Bris et al concluded, adding, “the role of cytoreduction and antithrombotic therapies needs to be explored in this context.”

Source: 

LE Bris Y, Galtier J, Naguib D, et al. Thrombosis with non-proliferative complete blood count indicative of underlying myeloproliferative neoplasm, sythrom, a study on behalf of the FIM group. Presented at ASH Annual Meeting and Exposition; December 10-13, 2022; New Orleans, LA. Abstract 4347.