Lactate accumulation promotes immunosuppression and fibrotic transformation of bone marrow microenvironment in myelofibrosis.

Background: Clonal myeloproliferation and fibrotic transformation of the bone marrow (BM) are the pathogenetic events most commonly occurring in myelofibrosis (MF). There is great evidence indicating that tumor microenvironment is characterized by high lactate levels, acting not only as an energetic source, but also as a signaling molecule.

Methods: To test the involvement of lactate in MF milieu transformation, we measured its levels in MF patients' sera, eventually finding a massive accumulation of this metabolite, which we showed to promote the expansion of immunosuppressive subsets.