Still a burning question: the interplay between inflammation and fibrosis in myeloproliferative neoplasms

Purpose of review Bone marrow fibrosis is the progressive replacement of blood-forming cells by reticulin fibres, caused by the acquisition of somatic mutations in hematopoietic stem cells. The molecular and cellular mechanisms that drive the progression of bone marrow fibrosis remain unknown, yet chronic inflammation appears to be a conserved feature in most patients suffering from myeloproliferative neoplasms. Recent findings Here, we review recent literature pertaining to the role of inflammation in driving bone marrow fibrosis, and its effect on the various hematopoietic and nonhematopoietic cell populations. Recent evidence suggests that the pathogenesis of MPN is primarily driven by the hematopoietic stem and progenitor cells, together with their mutated progeny, which in turn results in chronic inflammation that disrupts the bone marrow niche and perpetuates a disease-permissive environment. Emerging data suggests that specifically targeting stromal inflammation in combination with JAK inhibition may be the way forward to better treat MPNs, and bone marrow fibrosis specifically.

Automated summary

Bone marrow fibrosis is characterized by the replacement of blood-forming cells by reticulin fibres due to somatic mutations in hematopoietic stem cells, with chronic inflammation being a common feature in patients with myeloproliferative neoplasms. Recent studies suggest that the pathogenesis of MPNs is primarily driven by hematopoietic stem and progenitor cells, leading to chronic inflammation that disrupts the bone marrow niche. Targeting stromal inflammation in combination with JAK inhibition may be a promising approach to treat MPNs and bone marrow fibrosis.