Placental and serum levels of human Klotho in severe preeclampsia: A potential sensitive biomarker.

Introduction: The Klotho (KL) gene, initially defined as an anti-aging gene in mice, shares 86% of the amino acid sequence withthe human KL protein. The KL gene plays roles in endothelial nitric oxide production, angiogenesis, antioxidant enzyme production and protecting against endothelial dysfunction, all of which may be associated with preeclampsia (PE). Human KL is the precursor of the gene products: α-KL and β-KL. In this study, we evaluated the gene expression, serum and placental levels of human KL in women with severe PE, pregnant women with chronic hypertension and healthy pregnant controls. Also, the gene expression, serum and placental levels of human decorin (DCN) were evaluated.

Methods: A total of 36 patients with severe PE, 10 with chronic hypertension, and 28 with healthy controls were enrolled. Placental and serum levels together with of KL and DCN were measured by ELISA and alsogene expression of these were evaluated.

Results: Placental and serum KL levels were significantly higher in the PE than in the controls and in women with chronic hypertension. Serum DCN levels were significantly higher in the PE women compared to controls and pregnant women with chronic hypertension. Placental DCN was similar in PE and healthy controls. There was no significant difference in the gene expression of KL and DCN in the groups. The best cut-off level for human KL to identify the presence of PE was calculated as 12.48 pg/ml with a sensitivity of 100% and and specificity of 96%, whereas for DCN 62.33 ng/ml to assess the presence of PE with a sensitivity of 86.1% and a specificity of 88%.

Conclusion: Human KL may be a valuable marker for PE, with high sensitivity and specificity. It also appears to be more sensitive and specific than human DCN.