Kidney transplantation restored uncoupled bone turnover in end-stage renal disease.
BACKGROUND
While kidney transplantation (KTx) reverses many disorders associated with end-stage renal disease (ESRD), patients who have received KTx often have chronic kidney disease and bone and mineral disorder (CKD-MBD). However, it is unknown how bone metabolism changes by KTx.


METHODS
Living donor-KTx recipients (n = 34) at Tokyo Women's Medical University were prospectively recruited and the levels of bone-specific alkaline phosphatase (BAP) and serum cross-linked N-telopeptides of Type 1 collagen (NTX) were measured before, 6 and 12 months after transplantation.


RESULTS
Before KTx, serum BAP was within the reference range in more than half of patients while NTX was high in most patients. Serum NTX was higher in patients with longer dialysis durations compared to that with shorter durations before KTx. However, there was no difference in serum BAP between these patients. After KTx, BAP increased while NTX decreased along with the decline of PTH. In addition, the numbers of patients who showed high BAP and NTX were comparable after KTx.


CONCLUSIONS
These results suggest that bone formation is suppressed and uncoupled with bone resorption in patients with ESRD and this uncoupling is restored by KTx. Further studies are necessary to clarify the mechanism of bone uncoupling in patients with ESRD.
Division of Nephrology and Hypertension, Department of Internal Medicine, St. Marianna University School of Medicine, Kawasaki City, Japan. hirookawarazaki@yahoo.co.jp
Hiroo
H
Kawarazaki
Yugo
Y
Shibagaki
Ryo
R
Kido
Ichiro
I
Nakajima
Shohei
S
Fuchinoue
Katsuyuki
K
Ando
Toshiro
T
Fujita
Masafumi
M
Fukagawa
Satoshi
S
Teraoka
Seiji
S
Fukumoto
D000305:Adrenal Cortex Hormones / Q000627:therapeutic use; D000328:Adult; D000469:Alkaline Phosphatase / Q000097:blood; D015415:Biomarkers / Q000097:blood; D016723:Bone Remodeling / Q000187:drug effects; D001862:Bone Resorption / Q000097:blood; D001842:Bone and Bones / Q000187:drug effects* / Q000378:metabolism; D024042:Collagen Type I / Q000097:blood; D005260:Female; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D007564:Japan; D007676:Kidney Failure, Chronic / Q000097:blood / Q000601:surgery*; D016030:Kidney Transplantation; D016014:Linear Models; D019520:Living Donors; D008297:Male; D008875:Middle Aged; D010012:Osteogenesis; D010281:Parathyroid Hormone / Q000097:blood; D010455:Peptides / Q000097:blood; D011446:Prospective Studies; D006435:Renal Dialysis; D013997:Time Factors; D016896:Treatment Outcome
D000305:Adrenal Cortex Hormones; D015415:Biomarkers; D024042:Collagen Type I; D007166:Immunosuppressive Agents; C470125:PTH protein, human; D010281:Parathyroid Hormone; D010455:Peptides; C052929:collagen type I trimeric cross-linked peptide; D000469:Alkaline Phosphatase