Prognostic value of urinary pyridinium crosslinks and their derivatives in multiple myeloma

Bone disease is a common feature of multiple myeloma (MM). The goal of this study was to assess the prognostic significance of urinary markers of bone metabolism in MM. Urinary levels of total pyridinoline (T-Pyd), deoxypyridinoline (T-Dpd), crosslinked N-telopeptide (Ntx), C-telopeptide (Ctx) of type I collagen and immunologic free deoxypyridinoline (f-Dpd) were assessed in 82 consecutive, previously untreated MM patients (aged 65-75 years) diagnosed between June 1995 and December 1998. A correlation between disease stage according to the Durie-Salmon classification and T-Pyd (p=0.034) and T-Dpd (p=0.007) was observed, while T-Pyd (p=0.015) and to a lesser extent f-Dpd (p=0.081) were correlated to bone involvement measured by plain X-ray. None were correlated to M-component or magnetic resonance imaging (MRI). In univariate analysis high T-Pyd (p=0.007), T-Dpd (p=0.027), f-Dpd (p<0.001), and Ctx (p=0.011) were associated with shorter overall survival, whereas only f-Dpd (p=0.0025) was associated with a shorter disease-free survival. In multivariate analysis, C-reactive protein and f-Dpd were independent prognostic factors for overall survival. This retrospective analysis defined new independent prognostic indicators of survival in patients with newly diagnosed myeloma. Indeed, urinary markers of bone resorption can easily be measured at diagnosis and have independent prognostic significance to refine the prognosis of MM patients.