Activin A: a marker of mineral bone disorder in children with chronic kidney disease?

BACKGROUND

Activin A has been shown to enhance osteoclast activity and its inhibition results in bone growth. The potential role of activin A as a marker of chronic kidney disease-mineral bone disease (CKD-MBD) and its relationship with other markers has not been studied in children with CKD.

METHODS

A cross sectional study was conducted among 40 children aged 2 to 18 years with CKD (Stage 2 to 5; 10 in each stage) and 40 matched controls. Activin A, cathepsin K, FGF-23, PTH, serum calcium, phosphorous and alkaline phosphatase in both groups were measured and compared. The correlation of activin A and markers of CKD-MBD was studied. A p value of < 0.05 was considered significant.

RESULTS

The mean age of children with CKD was 9.30 ± 3.64 years. Mean levels of activin A in cases were 485.55 pg/ml compared to 76.19 pg/ml in controls (p < 0.001). FGF-23 levels in cases were 133.18 pg/ml while in controls it was 6.93 pg/ml (p < 0.001). Mean levels of cathepsin K were also significantly higher in cases as compared to controls. There was a progressive increase in activin A and cathepsin K levels with increasing stage of CKD. Activin A had a significant positive correlation with serum creatinine (r = 0.51; p < 0.001).

CONCLUSIONS

Activin A levels progressively rise with advancing CKD stage. These findings suggest that activin A can be a potential early marker of CKD-MBD in children.