High levels of serum soluble CD27 correlated with renal dysfunction

CD27 is expressed on lymphocytes, but also on renal tubules. On the damaged renal tubules, CD27 is cleaved into soluble CD27 (sCD27) and cytoplasmic tail CD27. Renal tubule apoptosis is induced by the CD27 ligand, Siva, binding to the truncated tail CD27. Theoretically, serum sCD27 should be a marker of renal tubule apoptosis. Serum sCD27 levels were measured by ELISA in 274 patients at University Hospital School of Medicine, Japan. Among 73 males and 63 females with high plasma creatinine levels, 68 (93%) males and 51 (81%) females showed high serum sCD27 values (>or=500 U/ml). In the 42 males with plasma creatinine levels of 1.18-5.00 mg/dl and the 55 females with plasma creatinine levels of 0.83-4.65 mg/dl, the correlation coefficients between plasma creatinine and sCD27 were 0.605 and 0.469, respectively. SCD27 was a more sensitive marker of renal tubule apoptosis than plasma creatinine. Of 138 patients with normal plasma creatinine, 42 showed high serum sCD27 levels (>or=500 U/ml). Among the 42 patients, 19 patients had high blood urea nitrogen and 11 patients showed plasma creatinine elevations 3-11 days later. Nine patients with hemolysis and 39 patients with aneurysms had clearly higher sCD27 levels of 1633+/-483 U/ml and 905+/-437 U/ml, respectively, than normal values of 215+/-57 U/ml ( n=27) ( P value >or=0.001). Vasodilators, hypotensors, diuretics, and drugs for gout, arrhythmia, thrombosis, and diabetes were prescribed in 40%, 37%, 33%, 13%, 8%, 8%, and 5% of the 78 patients analyzed with high sCD27 levels (>or=500 U/ml). In total, 59 (76%) patients were prescribed at least one of the drugs. In conclusion, serum sCD27 was a more sensitive indicator of renal tubule apoptosis than plasma creatinine, especially during the early stage of apoptosis. Tubule apoptosis with high serum sCD27 levels was found in patients with glomerular vascular injuries.