Changes in the mitogenic activity of platelet-derived growth factor(s) in patients with myeloproliferative disease.

Platelet-derived growth factor (PDGF) is thought to take part in the genesis of bone marrow fibrosis that can be found in patients with myeloproliferative diseases. We evaluated platelet mitogenic activity as the difference between serum and plasma activity in 8 patients with myeloproliferative disease. We observed a trend of lower values in 2 cases of polycythemia vera and 2 cases of essential thrombocythemia, as seen by other authors. Two patients suffering from chronic myeloid leukemia were within the normal range. In contrast, our 2 cases of idiopathic myelofibrosis showed increased levels. If confirmed by further studies, this could suggest a pathogenetic relationship between increased levels of PDGF and bone marrow fibrosis, and give differential diagnostic significance to the PDGF mitogenic assay in myeloproliferative diseases.