Skeletal implications of isolated bone marrow mastocytosis

Abstract

In the article on the isolated bone marrow mastocytosis (IBMM) as an underestimated subvariant of indolent systemic mastocytosis (ISM), Zanotti et al.1 reported that 54.7% of patients with unexplained/recurrent anaphylaxis or severe allergic reactions were found to be suffering from IBMM. They conclude that the incidence of IBMM can be frequently underestimated, especially in the face of a lack of collaboration among medical specialities, while early recognition can potentially reduce life-threatening events and/or severe skeletal complications. Although this is an extremely interesting finding depicting the problem of unrecognized IBMM, the Authors do not provide an acceptable level of information regarding the skeletal problems of the patients. Since bone densitometry (BMD) was performed in all patients and X-rays in selected cases, it would be helpful for the reader to know the skeletal implications of these subjects. Osteoporosis or osteopenia is by far the most frequently observed pathological skeletal sign in systemic mastocytosis reported in more than one-third of all patients, while osteolysis and osteosclerosis can occur, even simultaneously, in the same patient. In addition, osteoporosis can be the only presentation in IBMM; specifically among men IBMM can be found in up to 9% of patients with idiopathic osteoporosis.2 Furthermore, fractures, mostly vertebral, have been reported in approximately 15% of all patients with systemic mastocytosis.3 Serum tryptase is currently considered the test of choice in the initial assessment of suspected systemic mastocytosis cases.4 However, its cost-effectiveness in the evaluation of secondary osteoporosis is yet to be defined due to the lack of data regarding the real incidence of the disease among osteoporotic patients. It would be very important to know whether the Authors can confirm or not a low BMD and/or pathological fractures in patients with IBMM, especially among young patients. In the former case, the importance of considering the diagnosis of IBMM in subjects with a low BMD and/or fractures and a history of recurrent allergic reactions would be highlighted.