Osteoporosis is a highly prevalent illness, especially among postmenopausal women. Left untreated, it can lead to fragility and compression fractures; in turn, associated with increased mortality and morbidity. Diagnosis of osteoporosis is currently made by bone density scan (DEXA) or when the patient experiences symptoms (fragility or compression fractures).
This scientific report published in Nature is of great significance as for the first-time its authors identify a potential blood test to diagnose osteoporosis - without having patients undergo bone scanning or present with symptoms. The test is Cathepsin Z mRNA and is measured in human peripheral blood mononuclear cells. Cathepsin Z is a protease synthesized by both bone remodeling cells - osteoclast and osteoblasts.
The test is not influenced by acute or chronic inflammation. Its diagnostic positive predictive value (PPV) is 95% with a negative predictive value (NPV) of 80%. Authors found a strong correlation of elevated levels of Cathepsin Z mRNA in patients with osteopenia in addition to those with osteoporosis.
Although study findings need to be fully validated, the results are exciting. Early diagnosis and treatment of osteoporosis are crucial to preventing fractures and its complications.