STAINING OF BONE ALUMINUM - COMPARISON BETWEEN ALUMINON AND SOLOCHROME AZURINE AND THEIR CORRELATION WITH BONE ALUMINUM CONTENT

The aim of this study was to compare the sensitivity and specificity o f the two histochemical stains most commonly used as indirect markers of the aluminium bone content. The clinical study was made in 28 biops ies from patients undergoing haemodialysis and the experimental study in 17 tibias from Wistar rats aluminium overloaded and with different deposits of iron. All samples were stained with aluminon, solochrome a zurine and Perls and aluminium bone content was also measured. When th e positive cases with Perls were excluded in the clinical study (witho ut iron interference), the trabecular surface stained with solochrome azurine correlated with the aluminium bone content (r = 0.71, P < 0.00 1). With aluminon, on the other hand, no correlation was found. Soloch rome azurine was always positive with aluminium contents greater than 8 mu g/g. Aluminon was positive over 17 mu g/g. In the experimental st udy, the iron concentration, in addition to other parameters, was also measured. As in the clinical study, the trabecular surface stained wi th solochrome azurine correlated with the aluminium content. If the po sitive Perls cases were excluded, the trabecular surface stained with solochrome azurine doubted the trabecular surface stained with alumino n (P < 0.001). No intratrabecular aluminon staining was observed while the intratrabecular solochrome staining correlated with the aluminium content (P < 0.001). Solochrome azurine was more sensitive than the a luminon and its lack of specificity can be easily corrected by employi ng Perls staining to exclude the iron interference.