Thrombopoietin mimetic-induced bone marrow fibrosis

Thrombopoietin receptor agonists (TPO-RA) stimulate megakaryopoiesis and can increase platelet production in ITP. An increase in bone marrow reticulin is a well-recognized phenomenon1 though clinically significant, severe grades with collagen deposition are rare. Discontinuation of TPO-RA may not be necessary in all cases but has been shown to lead to regression of bone marrow fibrosis in cases reported. The authors declare no conflicts of interest.