Testing for mast cell disease may help explain idiopathic osteoporosis cases
MedWire News: Vertebral osteoporosis and fractures are common in patients with indolent systemic mastocytosis (ISM), finds research.
In a systematic assessment of osteoporosis indicators, Maurizio Rossini ( University of Verona, Italy) and team suggest that evaluating patients with idiopathic osteoporosis for ISM might help identify the cause of bone loss.
They studied 82 patients (37 women), with a mean age of 48 years, who had been diagnosed with ISM, often following the appearance of typical skin lesions or a severe allergic reaction to a sting from a hymenopteran insect (wasp, bee, or ant).
Mastocytosis refers to an excess of mast cells within organs, most commonly the skin and bone marrow, which is termed systemic when they affect extracutaneous organs such as bone marrow. ISM has the least severe symptoms of the four types of systemic mastocytosis described by the World Health Organization (WHO).
Previous research regarding the incidence of mastocytosis-related osteoporosis has, overall, been inconclusive, perhaps due to poor methodology, say the study authors.
To investigate further, they assessed patients' lumbar and femoral bone mineral density (BMD) using dual-energy X-ray absorptiometry, serum bone turnover markers (BTM), and the prevalence of vertebral and non-vertebral fractures.
"The present study includes one of the largest number of patients with ISM so far reported," say Rossini and colleagues.
After excluding three women from the analysis because they suffered from conditions that have an established association with osteoporosis, the researchers diagnosed osteoporosis in 20% of patients, seven women and nine men, according to the traditional WHO criteria (BMD T-score <-2.5).
Mastocytosis-related low BMD occurred in three women and 13 men when using a defining threshold of a Z-score lower than -2.0, which is similar to that used for studies involving patients with cystic fibrosis
They also found that the prevalence of mastocytosis-related low BMD and vertebral fracture was not significantly related to whether or not the patients showed ISM skin involvement. "This is an important issue because in absence of trigger factors such as anaphylaxis, osteoporosis might be the only manifestations of a latent ISM!" write the researchers.
They conclude: "Our study indicates that osteoporosis of unknown etiology should lead to the suspicion of bone marrow mastocytosis."
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By Chloe McIvor