Usefulness of whole PTH assay in patients with renal osteodystrophy--correlation with bone scintigraphy.
OBJECTIVE
Intact parathyroid hormone (PTH) assay has recently been reported to be effective in evaluating both 1-84 PTH (whole PTH) and inactive 7-84 PTH. Inactive 7-84 PTH is considered to be increased in hemodialysis patients and to prevent the effects of 1-84 PTH, and intact PTH is considered to overestimate the PTH activity in these patients. As such, a whole PTH assay has recently been developed. The purpose of this study was to examine the usefulness of a whole PTH assay using the bone to soft tissue (B/ST) ratio on bone scintigraphy.


METHODS
Twenty-five hemodialysis patients were included in our study. In all patients, bone scintigraphy and a blood test [whole PTH, intact PTH, alkaline phosphatase (ALP), calcium (Ca), and phosphorus (P)] were performed. Regions of interest (ROIs) were drawn around the cranium, lumbar vertebrae, left femoral neck, and soft tissue of the medial left thigh to obtain the B/ST ratio.


RESULTS
The B/ST ratio of the cranium and left femoral neck correlated with whole PTH and intact PTH. In particular, the B/ST ratio of the cranium correlated most significantly with the value of whole PTH. Whole PTH levels correlated with intact PTH levels (r = 0.891, p < 0.0001).


CONCLUSIONS
Our data indicate that a whole PTH assay may be useful in evaluating PTH activity using the B/ST ratio. The B/ST ratio of the cranium may reflect the bone metabolism of hemodialysis patients.
Division of Nuclear Medicine, PET Center and Department of Radiology, Kurume University School of Medicine, Fukuoka, Japan. hayato@med.kurume-u.ac.jp
Hayato
H
Kaida
Masatoshi
M
Ishibashi
Hidemi
H
Nishida
Kenkichi
K
Baba
Yuji
Y
Hiromatsu
Seiya
S
Okuda
Naofumi
N
Hayabuchi
D000328:Adult; D000368:Aged; D001842:Bone and Bones / Q000000981:diagnostic imaging* / Q000378:metabolism*; D012080:Chronic Kidney Disease-Mineral and Bone Disorder / Q000097:blood* / Q000175:diagnosis* / Q000000981:diagnostic imaging; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010281:Parathyroid Hormone / Q000097:blood*; D011379:Prognosis; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013669:Technetium Tc 99m Medronate / Q000031:analogs & derivatives* / Q000493:pharmacokinetics
D010281:Parathyroid Hormone; D019275:Radiopharmaceuticals; C024226:technetium Tc 99m hydroxymethylene diphosphonate; D013669:Technetium Tc 99m Medronate