Abstract: SA-PO880

Bone Disease Characterization in a Portuguese Predialysis Cohort

Session Information

  • Mineral Disease: CKD-Bone
    November 04, 2017 | Location: Hall H, Morial Convention Center
    Abstract Time: 10:00 AM - 10:00 AM

Category: Mineral Disease

  • 1203 Mineral Disease: CKD-Bone

Authors

  • Neto, Ricardo, Centro Hospitalar São João, Porto, Portugal, Porto, Portugal
  • Pereira, Luciano, Centro Hospitalar São João, Porto, Portugal, Porto, Portugal
  • Frazão, João, Centro Hospitalar São João, Porto, Portugal, Porto, Portugal
Background

Renal osteodystrophy (ROD) is an early and common complication of chronic kidney disease (CKD). Histomorphometry is the gold-standard diagnostic tool for ROD, but there is little data on bone histological changes in pre-dialysis patients. Most studies are old and results are inconsistent. We report the results of bone biopsies performed on a cohort of Portuguese pre-dialysis patients.

Methods

Transiliac bone biopsy after double tetracycline labelling was performed on 35 consecutive patients enrolled in our pre-dialysis clinic. Inclusion criteria were age between 18 and 80 years old and glomerular filtration rate between 15 and 60 mL/min/1.73 m^2. Patients were excluded if they were on calcium salts, any form of vitamin D, steroids or bisphosphonates. KDIGO TMV classification was used to characterize biopsy results. Clinical and biochemical data were recorded at the time of biopsy.

Results

Four patients (11.4%) were excluded due to inadequate bone sample. Thirty-one biopsies were therefore analyzed. Twenty-two patients (70.9%) were male. Mean age was 67.3 ± 8.1 years. Mean serum creatinine and glomerular filtration rate were 2.2 ± 0.4 mg/dL and 27.6 ± 7.0 mL/min/1.73 m2, respectively. Mean serum calcium, phosphorus, intact parathyroid hormone (iPTH) and native vitamin D (VD) levels were 9.0 ± 0.5 mg/dL, 3.5 ± 0.6 mg/dL, 140.6 ± 130.2 pg/mL and 17.8 ± 11.9 ng/mL, respectively. Twenty-four patients (77.4%) had normal bone histology, 3 (9.7%) had adynamic disease, 3 (9.7%) had mild hyperparathyroid disease and one (3.2%) had mixed uremic osteodystrophy. No cases of osteomalacia were found. Except for mineralization lag time and bone volume, histomorphometric parameters did not significantly differ between histological classes. Despite a trend for higher iPTH with rising bone formation rate, levels did not significantly differ between groups.

Conclusion

In a contemporary Portuguese pre-dialysis cohort, roughly 3/4 of the patients had normal bone histology, one tenth had adynamic bone disease and another tenth had mild hyperparathyroid disease. There was one case of mixed disease and none of osteomalacia. Our results also suggest that biochemical testing are not predictive of histological findings, thus highlighting the importance of bone biopsy as the gold-standard tool to evaluate ROD. Further histomorphometric studies are needed to enlighten the spectrum of ROD in pre-dialysis CKD.