Bone biomarkers in de novo renal transplant recipients

Successful kidney transplantation (partly) corrects the physiologic and metabolic abnormalities driving chronic kidney disease - mineral and bone disorders. At the same time, renal transplant recipients are exposed to immunosuppressive agents that may affect bone metabolism. Bone biomarkers have been suggested as surrogates of or adjuncts to bone biopsy and imaging techniques to assess bone health and to classify risk of bone loss and fractures. Bone biomarkers may be classified as circulating factors that affect bone metabolism (commonly referred to as bone metabolism markers) or that reflect bone cell number and/or activity (commonly referred to as bone turnover markers). A growing body of evidence shows that successful renal transplantation has a major impact on both bone metabolism and bone turnover. Analytical issues, including the cross-reactivity with fragments, complicate the interpretation of bone biomarkers, especially in the setting of a rapid changing kidney function, as is the case after successful renal transplantation. Overall, bone turnover seems to decline following renal transplantation, but inter-individual variability is substantial. Preliminary evidence indicates that bone biomarkers may be useful in guiding mineral and bone therapy in renal transplant recipients.