Spectrum of Renal Osteodystrophy and Aluminum Accumulation in Egyptian CKD Patients: A Cross-Sectional Bone Biopsy Study

Background : Renal osteodystrophy varies among populations. Different genetic, and environmental factors and prescription patterns may explain this variation. Egyptian Renal osteodystrophy is not sufficiently studied. Although bone biopsy is the gold standard tool, no single study reported the actual Renal osteodystrophy spectrum based on bone biopsy in Egypt nor Africa. International guidelines must consider the different patterns in developing countries. Methodology: The ISN-sistership program enabled us to create an Egyptian bone biopsy consortium that provided a nation-wide specialized CKD-MBD service. We included all CKD patients who were referred to unexplained bone pain, osteoporosis, or abnormal CKD-MBD laboratory parameters. Bone biopsy was offered for those who had clinical indications. Results: Over 2 years, 270 patients were recruited: 118 pre-dialysis, 97 on HD, 21 on PD, and 34 excluded. Non-invasive evaluation suggested that high bone turnover prevailed. Fourteen patients consented to the bone biopsy; all were on HD. Unexpectedly, various degrees of positive aluminum staining were present in 93% of biopsied patients, despite negative results in the dialysate water and nonuse of aluminum-based phosphate binders. Root cause analysis was done triggering an environmental alarm for potential sources in food, water, and drug manufacturing. Aluminum-induced suppression of bone cells was confirmed by low turnover biomarkers in patients with significant aluminum accumulation. Moreover, FGF23 was significantly higher in the same group (z=-2.082, p-value=0.037). Conclusion: To conclude, Aluminum bone disease is not extinct yet. Of the biopsied patients, 93% had variable degrees of positive aluminum staining and 57% had significant aluminum accumulation. Extra efforts are needed to eliminate this bone toxin.