Bone morbidity in chronic myeloproliferative neoplasms

Patients with the classical Philadelphia chromosome-negative chronic myeloproliferative neoplasms including essential thrombocythemia, polycythemia vera and primary myelofibrosis often suffer from comorbidities, in particular, cardiovascular diseases and thrombotic events. Apparently, there is also an increased risk of osteoporotic fractures among these patients. However, the true prevalence, mechanisms involved and therapeutic implications are not well described. In this review, we summarize what is currently known about possible associations between bone disease and chronic myeloproliferative neoplasms. Chronic inflammation has been suggested to explain the initiation of clonal development and progression in chronic myeloproliferative neoplasms. Decreased bone mineral density and enhanced fracture risk are well-known manifestations of many chronic systemic inflammatory diseases. As opposed to systemic mastocytosis (SM) where pathogenic mechanisms for bone manifestations probably involve effects of mast cell mediators on bone metabolism, the mechanisms responsible for increased fracture risk in other chronic myeloproliferative neoplasms are not known.