Background
α-Klotho (αKl) regulates mineral metabolism such as calcium ion (Ca2+) and inorganic phosphate (Pi) in circulation. Defects in mice result in clinical features resembling disorders found in human aging. Although the importance of transmembrane-type αKl has been demonstrated, less is known regarding the physiological importance of soluble-type αKl (sαKl) in circulation.
Objectives
The aims of this study were: 1) to establish a sandwich ELISA system enabling detection of circulating serum sαKl, and 2) to determine reference values for sαKl serum levels and relationship to indices of renal function, mineral metabolism, age and sex in healthy subjects.
Results
We successively developed an ELISA to measure serum sαKl in healthy volunteers (n=142, males 66) of ages (61.1 ± 18.5 yr). The levels (mean ± SD) in these healthy control adults were as follows: total calcium (Ca; 9.46 ± 0.41 mg/dL), Pi (3.63 ± 0.51 mg/dL), Blood urea nitrogen (BUN; 15.7 ± 4.3 mg/dL), creatinine (Cre; 0.69 ± 0.14 mg/dL), 1,25 dihydroxyvitamin D (1,25(OH)2D; 54.8 ± 17.7 pg/mL), intact parathyroid hormone (iPTH; 49.2 ± 20.6 pg/mL), calcitonin (26.0 ± 12.3 pg/mL) and intact Fibroblast growth factor (FGF23; 43.8 ± 17.6 pg/mL).
Serum levels of sαKl ranged from 239 to 1266 pg/mL (mean ± SD; 562 ± 146 pg/mL) in normal adults. Although sαKl levels were not modified by gender or indices of mineral metabolism, sαKl levels were inversely related to Cre and age. However, sαKl levels in normal children (n=39, males 23, mean ± SD; 7.1 ± 4.8 years) were significantly higher (mean ± SD; 952 ± 282 pg/mL) than those in adults (mean ± SD; 562 ± 146, P<0.001). A multivariate linear regression analysis including children and adults in this study demonstrated that sαKl correlated negatively with age and Ca, and positively with Pi. Finally, we measured a serum sαKl from a patient with severe tumoral calcinosis derived from a homozygous missense mutation of α-klotho gene. In this patient, sαKl level was notably lower than those of age matched controls.
Conclusion
We established a detection system to measure human serum sαKl for the first time. Age, Ca and Pi seem to influence serum sαKl levels in a normal population. This detection system should be an excellent tool for investigating sαKl functions in mineral metabolism.
Abstract. Chronic allograft nephropathy (CAN) is due to both immunologic and non-immunologic factors and results in the development of nonspecific pathologic features that may even be present in long-term well-functioning renal allografts. To investigate the natural history of CAN and potential risk factors associated with progression of these histologic lesions, this study evaluated the of histologic alterations of 124 sequential protocol biopsies performed at 2, 3, and 5 yr after transplantation in 46 patients who exhibited histologic evidence of CAN in the 1-yr biopsy.
The new polynomial eGFR formula showing the relationship with body length and serum Cr level may be applicable for clinical screening of renal function in Japanese children and adolescents aged between 2 and 18 years.
End-stage renal disease requiring renal replacement therapy (RRT) during the neonatal period is a very rare condition, and little information is available regarding long-term RRT and outcomes. To gain more information, we performed a collaborative study on patient characteristics and treatment outcomes in children who started RRT as neonates during their first month of life between 2000 and 2011 who were prospectively registered in the ESPN/ERA-EDTA, the IPPN (since 2007), the Japanese registry, or the Australian and New Zealand Dialysis and Transplant (ANZDATA) registry. During the first month of life, 264 patients from 32 countries started RRT and were followed for a median of 29 months (interquartile range 11-60 months). Most neonates (242) started on peritoneal dialysis, 21 started on hemodialysis, and 1 patient with a transplant. The most important causes of renal failure were congenital anomalies of the kidney and urinary tract in 141, cystic kidneys in 35, and cortical necrosis in 30. Within 2 years after the start of RRT, 69 children changed dialysis modality and 53 received a renal transplant. After a median of 7 months, 45 children had died, mainly because of infection, resulting in an estimated 2-year survival of 81%, and 5-year survival of 76%. Growth retardation (63%), anemia (55%), and hypertension (57%) were still major problems after 2 years. Thus, relatively good medium-term patient survival may be achieved with RRT started during the neonatal period, but specific therapeutic challenges continue to exist in this age group.
123Clin Exp Nephrol (2013) 17:155-173 DOI 10.1007 nephritic syndrome (55.4 % and 50.0 % in 2009 and 2010, respectively), followed by nephrotic syndrome (22.4 % and 27.0 %); the most frequent pathological diagnosis as classified by the pathogenesis was IgA nephropathy (31.6 % and 30.4 %), followed by primary glomerular diseases (except IgA nephropathy) (27.2 % and 28.1 %). Among the primary glomerular diseases (except IgA nephropathy) in the patients with nephrotic syndrome, membranous nephropathy was the most common histopathology in 2009 (40.3 %) and minor glomerular abnormalities (50.0 %) were the most common in 2010 in native kidneys in the J-RBR. Five new secondary and longitudinal research studies by the J-KDR were started in 2009 and one was started in 2010.
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