Bone density, bone markers and bone radiological features in mastocytosis

We examined the association between severity of disease in mastocytosis and skeletal manifestation and bone markers in 16 patients varying in extent of mastocytosis as determined by the urine excretion of methylimidazoleacetic acid. Both osteoporosis and osteosclerosis were found. Bone density in the hip was significantly higher (p < 0.05) in both men and women with an enhanced histamine metabolite excretion. Patients with only moderately increased mast cell mass had low bone mineral density in the hip, osteoporosis and vertebral fractures. The different skeletal disease patterns in mastocytosis might be the effect on osteoblasts and osteoclasts of biologically active substances. Mast cells release a number of vasoactive substances, including histamine which promotes osteoblasts and heparin and prostaglandin D2 which induce bone resorption by activation of osteoclasts. Systemic mastocytosis is a rare disease characterized by multi-organ infiltration by mast cells and with varying skeletal manifestations including osteoporosis. Treatment with bisphosphonates may be beneficial in arresting osteoporosis in this disorder.