TY - JOUR
T1 - Validation of an immunoassay for soluble Klotho protein
T2 - Decreased levels in diabetes and increased levels in chronic kidney disease
AU - Devaraj, Sridevi
AU - Syed, Basir
AU - Chien, Alexander
AU - Jialal, Ishwarlal
PY - 2012/3
Y1 - 2012/3
N2 - The Klotho gene has been identified as an aging suppressor gene that encodes a transmembrane protein, which is expressed primarily in renal tubules. There are 2 forms of Klotho, membrane and secreted. However, there is a paucity of data on levels of soluble Klotho in diseases like diabetes and kidney disease. We validated an enzyme-linked immunosorbent assay for Klotho and quantitated Klotho levels separately in patients with diabetes and also in patients with chronic kidney disease (CKD). The Klotho assay showed good precision and was linear down to 19 ng/mL. There were no significant effects on Klotho levels with the addition of common interferents such as ascorbate, triglycerides, or hemolysis; only bilirubin (250 mg/L) significantly reduced Klotho levels (P < .05). There was a significant reduction in Klotho levels in samples with glycated hemoglobin (HbA 1c) levels of 6.5% or more compared with control samples (HbA 1c < 6.5%; P < .001). We also documented significantly higher levels of Klotho with CKD. Thus, we validated an assay for Klotho and made the novel observation that levels are decreased in diabetes and increased in CKD. Copyright
AB - The Klotho gene has been identified as an aging suppressor gene that encodes a transmembrane protein, which is expressed primarily in renal tubules. There are 2 forms of Klotho, membrane and secreted. However, there is a paucity of data on levels of soluble Klotho in diseases like diabetes and kidney disease. We validated an enzyme-linked immunosorbent assay for Klotho and quantitated Klotho levels separately in patients with diabetes and also in patients with chronic kidney disease (CKD). The Klotho assay showed good precision and was linear down to 19 ng/mL. There were no significant effects on Klotho levels with the addition of common interferents such as ascorbate, triglycerides, or hemolysis; only bilirubin (250 mg/L) significantly reduced Klotho levels (P < .05). There was a significant reduction in Klotho levels in samples with glycated hemoglobin (HbA 1c) levels of 6.5% or more compared with control samples (HbA 1c < 6.5%; P < .001). We also documented significantly higher levels of Klotho with CKD. Thus, we validated an assay for Klotho and made the novel observation that levels are decreased in diabetes and increased in CKD. Copyright
KW - Aging
KW - Chronic kidney disease
KW - Diabetes
KW - Fibroblast growth factor
KW - Inflammation
KW - Klotho
UR - http://www.scopus.com/inward/record.url?scp=84859259028&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84859259028&partnerID=8YFLogxK
U2 - 10.1309/AJCPGPMAF7SFRBO4
DO - 10.1309/AJCPGPMAF7SFRBO4
M3 - Article
C2 - 22338062
AN - SCOPUS:84859259028
VL - 137
SP - 479
EP - 485
JO - American Journal of Clinical Pathology
JF - American Journal of Clinical Pathology
SN - 0002-9173
IS - 3
ER -