Abstract

A total of 112 undecalcified bone biopsies from 67 patients under treatment for chronic renal failure by maintenance haemodialysis was available for retrospective study. The patients were divided into three groups. Group I (15 cases) had been dialysed for the majority of the time in their own homes with a fluid containing a low concentration of aluminium. Group II (28 cases) had been dialysed exclusively in hospital (prior to 1978) with a fluid containing a high concentration of aluminium and group III (24 cases) had been treated exclusively in hospital (from 1978 onwards) with a fluid of low aluminium concentration. The tissues from these groups were subjected to histoquantitative assessment and stained by a histochemical technique to demonstrate aluminium salt. In group II, 71.4% of cases showed positive aluminium staining reactions (at the osteoid/mineralised tissue interface) compared to 26.6% in group I and 37.5% in group III. Staining reactions were also more extensive in group II cases. The osteoid volume was significantly increased and the calcification front extents significantly decreased in group II compared to both groups I and III. A comparison of histochemically positive with negative cases in each group showed a significantly increased osteoid volume and significantly decreased calcification fronts in the positive cases. It was, therefore, concluded that haemodialysis against a fluid containing a high concentration of aluminium leads to intraosseous aluminium accumulation of greater degree in a larger number of patients than a fluid with low aluminium content and that there is an accompanying osteomalacia manifest by an increase in osteoid volume together with diminution in the extent of the calcification fronts.