Staining of bone for aluminum: use of acid solochrome azurine

Histochemical identification of wear debris released by alumina-on-alumina hip prostheses in the periprosthetic tissues

BACKGROUND

Tribological studies have shown that the most used couples for hip prostheses consist of metal-on-polyethylene and alumina-on-alumina prostheses. Over time, wear products accumulate in the joint cavity and in the periprosthetic tissues. Although polyethylene and metal are easily identifiable by microscopy in periprosthetic tissues, alumina particles are very difficult to identify.

HYPOTHESIS

The fluorescent azo-dye lumogallion was evaluated as a suitable histochemical stain for alumina particles in periprosthetic tissues.

MATERIAL AND METHOD

In 28 patients who had a prosthetic revision of an alumina-on-alumina prosthesis, periprosthetic tissues were removed and embedded in paraffin; sections were stained with HPS (for conventional diagnosis) or with lumogallion. Sections were examined for wear particles in light and fluorescence microscopy. Some sections were counter-stained using DAPI for visualization of cell nuclei.

RESULTS

The wear particles of the alumina-alumina prostheses were very difficult to identify on the HPS stained sections; they were clearly evidenced by lumogallion staining with a bright orange fluorescence. The stain revealed large quantities of particles (of the order of several thousand per section). Only two patients had no particles. The staining technique identified numerous particles that were not visible on HPS-stained sections in macrophages, synoviocytes and fibroblasts.

CONCLUSION

This staining, which has been validated in neuromuscular pathology for the identification of alumina used as a vaccine adjuvant, gave successful results in the present study. Alumina particles are modified when they are phagocytized by macrophages. lumogallion staining easily shows the presence of thousands of wear particles released by alumina-on-alumina prostheses in periprosthetic tissues.

LEVEL OF EVIDENCE

V expert opinion study.

A sensitive stain for aluminum in undecalcified cancellous bone

Aluminum is known to accumulate with age in bone and other tissues of humans, even in the absence of renal disease. Our study aimed to develop a histological staining method sufficiently sensitive to detect aluminum in plastic sections of undecalcified bone biopsies from healthy volunteers as well as from patients with renal and non-renal bone diseases. We used quantitative histomorphometry to measure the percentage of trabecular surface stained by aluminum and found that our new method was approximately 50% more sensitive for detecting aluminum than the Acid Solochrome Azurine (ASA) method which in turn was significantly more sensitive than the Aluminon method. Aluminon is widely used in pathology laboratories for diagnostic purposes despite concerns in the literature about Aluminon's limited sensitivity for aluminum. Our histomorphometric results showed that the newly developed method stained approximately 10% of the trabecular surface in bone sections from healthy controls, 38% from renal patients, 26% from patients with vitamin D deficiency, and 29% from patients with osteoporosis. Histomorphometric measurements of aluminum-stained trabecular surfaces in sections stained with ASA were consistent with those obtained in Walton-stained sections but proportionately lower. Moreover, the Walton and ASA methods stained aluminum at similar locations in adjacent bone sections. As the ASA and Walton methods are considerably more sensitive for bone aluminum than the Aluminon method, we recommend that either of them should be used in place of the Aluminon method for routine diagnostic purposes.

Specific measurement of PTH (1-84) in various forms of renal osteodystrophy (ROD) as assessed by bone histomorphometry

BACKGROUND

Parathyroid hormone (PTH) measurements serve as a noninvasive, diagnostic tool for the assessment of renal osteodystrophy (ROD). Their value has been questioned following reports indicating that all commercially available intact PTH (I-PTH) assays cross-react with amino terminally truncated PTH fragments. Because these fragments can account for 50% of total PTH, their detection will overestimate the true PTH concentration and may lead to diagnostic inaccuracies. The aim of this study was to evaluate the specific Bio-Intact PTH (1-84) Assay (BI-PTH) in patients with various types of ROD confirmed by bone biopsy.

METHODS

Bone biopsies were taken from 132 patients with chronic kidney disease (CKD) stages 3 to 5, and quantitative bone histomorphometry was done. Plasma PTH levels were measured using both the BI-PTH and I-PTH assays on an automated analyzer.

RESULTS

Patients with CKD stages 3/4 and low turnover skeletal lesions had BI-PTH values (pg/mL, mean +/- SD) of 35 (+/-34) and I-PTH values of 59 (+/- 63). Corresponding values for BI-PTH and I-PTH in those with high turnover lesions were 141 (+/-60) and 221 (+/-106). Patients with CKD stage 5 and low turnover skeletal lesions had BI-PTH and I-PTH levels of 51 (+/-38) and 90 (+/-60), respectively, whereas the corresponding results for BI-PTH and I-PTH in those with high turnover lesions were 237 (+/-214) and 461 (+/-437). The areas under the receiver operating characteristic (ROC) curves for distinguishing low turnover from high turnover lesions were 0.94 for BI-PTH and 0.91 for I-PTH in CKD stages 3/4 and 0.86 for BI-PTH and 0.85 for I-PTH in CKD stage 5. Among all patients, BI-PTH levels are approximately 50% lower than I-PTH levels, but the results of the two assays are correlated highly (R2 = 0.92).

CONCLUSION

Plasma PTH measurements using either the BI-PTH or I-PTH assay effectively identify patients with reduced bone turnover and serve to distinguish this subgroup from those with high turnover lesions of renal bone disease. Both assays provide better diagnostic discrimination for this purpose than calculated values for the ratio of PTH (1-84)/amino terminally truncated PTH fragments.

The effect of an iron supplement on serum aluminum level and desferrioxamine mobilization test in hemodialysis patients

BACKGROUND

The serum aluminum (Al) measurement with desferrioxamine (DFO) mobilization is a screening test for uremic patients with an Al overload. In these patients, body iron status is one of the factors affecting the serum Al level. This study is designed to elucidate the effects of iron supplements on the serum Al and the DFO mobilization test.

METHODS

Our study featured ten hemodialysis patients with iron deficiency anemia. The iron supplement was given intravenously with saccharated ferric oxide, 40 mg three times weekly, at the end of each hemodialysis. The total amount of iron supplement was 1,000 mg. All the patients underwent a DFO test at a dose of 5 mg/kg. The same test was repeated two weeks after completion of the iron supplement.

RESULTS

After the iron supplement, patients' iron deficiency anemia improved with a serum ferritin elevation from 312.4 +/- 589.5 to 748.2 +/- 566.2 microg/L (p < 0.01), and iron saturation from 21.6 +/- 20.3 to 41.1 +/- 21.7% (p = 0.06). The basal serum Al level decreased from 34.3 +/- 13.8 to 21.8 +/- 8.5 microg/L (p = 0.01). In the DFO mobilization test, the peak serum Al level decreased from 63.4 +/- 19.3 to 50.7 +/- 20.5 microg/L (p < 0.01). The amount of Al increment (deltaAl) in DFO test was not changed (29.1 +/- 12.0 vs. 28.9 +/- 15.9 microg/L, p = 0.86). The change in basal Al level tended to negatively correlate with the percentage of increment in iron saturation (r = -0.628, p = 0.05).

CONCLUSION

Results in this study suggest that iron supplements may significantly reduce the basal serum Al and peak Al in DFO mobilization test, without significant change of the mean deltaAl. The data presented indicate that in the interpretation of serum aluminum levels the iron status should be taken into account.

Different patterns of renal osteodystrophy in Iberoamerica

The various forms of renal osteodystrophy are predominant hyperparathyroid bone disease, mixed uremic osteodystrophy, low turnover osteomalacia, and adynamic bone disease. The present study analyses a total number of 1,209 bone biopsies from 5 different countries (Brazil, Uruguay, Argentina, Portugal, and Spain). Low turnover osteomalacia and mixed uremic osteodystrophy were more common in Brazil, Uruguay, and Argentina than in Portugal and Spain whereas predominant hyperparathyroid bone disease was seen more often in Portugal and Spain. In all centers, independent of the aluminum staining technique used, the extent of aluminum deposited in bone was greater in patients presenting with low bone turnover, whether from low turnover osteomalacia or adynamic bone disease, than in the predominant hyperparathyroid bone disease. In summary, even though recent reports have indicated that, over the last decade, the incidence of aluminum-induced toxicity was reduced, aluminum still seems to be implicated in a great percentage of symptomatic low bone remodelling lesions in Iberoamerica.

Aplastic osteodystrophy without aluminum: the role of "suppressed" parathyroid function

We evaluated 259 dialysis patients using serum parathyroid hormone (PTH, IRMA; normal range 1 to 5.5 pM or 10 to 55 pg/ml), the deferoxamine infusion test and iliac crest bone biopsy to determine the various forms of renal osteodystrophy and their risk factors. Although half of the biopsied patients had low turnover osteodystrophy, evidence of aluminum toxicity was present in only 1/3 of them. Additional risk factors for this bone lesion included treatment with peritoneal dialysis, ingestion of calcium carbonate, diabetes mellitus and advanced age. The PTH levels in patients with the aplastic lesion were significantly lower than in patients with normal or high bone turnover lesions [7.7 +/- 6.1 vs. 36.9 +/- 3.2 pM (77 +/- 61 vs. 369 +/- 32 pg/ml), P < 0.0001]. Aside from hypercalcemia, these patients were relatively asymptomatic. In a second study, 10 patients on peritoneal dialysis with the aplastic lesion had their dialysate calcium lowered from 1.62 to 1.0 mM. This resulted in a significant increase in PTH levels, from [3.7 +/- 0.8 to 10.6 +/- 1.9 pM (37 +/- 8 to 106 +/- 19 pg/ml), P < 0.001] which persisted over the nine-month observation period. In conclusion, the aplastic lesion is the most common form of renal osteodystrophy, with aluminum intoxication implicated in only 1/3 of the cases. In the remainder, factors identified include therapy with peritoneal dialysis using supraphysiological dialysate calcium, oral CaCO3 intake and diabetes mellitus.(ABSTRACT TRUNCATED AT 250 WORDS)

Detection of subtle aluminum-related renal osteodystrophy

We compared the sensitivity of aurin tricarboxylic acid (ATA) or acid solochrome azurine (ASA) for detecting bone aluminum histochemically in 87 biopsy specimens obtained between 1983 and 1987 from 84 patients receiving dialysis therapy. Two consecutive biopsy sections were stained, one with ATA and the other with ASA, and then interpreted independently by two experienced observers. Three groups were established: group 1 (N = 61) had positive results of both ATA and ASA staining, group 2 (N = 25) had negative ATA but positive ASA sections, and group 3 (N = 1) had negative results of both ATA and ASA. No significant differences existed between groups 1 and 2 for age of the patients or serum calcium or immunoreactive parathyroid hormone levels. Patients in group 1 had significantly higher bone aluminium content (110 versus 61 micrograms/g dry ash weight), higher serum aluminum levels (151 versus 26 ng/ml), and longer duration of dialysis (85 versus 30 months) than did patients in group 2. Bone biopsy diagnoses (group 1 versus group 2) included low-turnover bone disease, 8 versus 7; osteomalacia, 26 versus 0; mixed uremic bone disease, 10 versus 1; hyperparathyroidism, 12 versus 14; and mild uremic bone disease, 5 versus 4. On the basis of ATA staining, 7 of 15 patients with low-turnover and 1 of 11 patients with mixed uremic bone disease may have been incorrectly diagnosed as having non-aluminum-related bone disorders. The levels of bone and serum aluminum were lower in group 2 than in group 1 but still much higher than normal.(ABSTRACT TRUNCATED AT 250 WORDS)

The spectrum of bone disease in end-stage renal failure--an evolving disorder

We have assessed the bone histology in 259 chronic dialysis patients, all of whom were in the same dialysis program. All patients had bone biopsies with quantitative histomorphometry, intact parathyroid hormone (PTH) measurements, basal and deferoxamine stimulated serum aluminum levels. Results demonstrate the increased incidence of the recently described aplastic bone lesion, particularly in patients treated with peritoneal dialysis (PD). Aluminum-related bone disease is much less common than previously described, perhaps in relation to the declining use of aluminum as a phosphate binder. A different pattern of bone lesions is seen in PD as compared with hemodialysis (HD), with low turnover disorders comprising 66% of the lesions seen in PD and high turnover lesions accounting for 62% of the bone histologic findings in HD. The difference in these patterns may relate to alterations in PTH levels, as mean PTH levels in HD patients were 2-1/2 times the levels found in PD patients (P < 0.0005), while older age, higher prevalence of diabetes and a shorter duration of dialysis may also have contributed to the findings in the PD patients. We suggest that PD, perhaps by maintaining calcium at higher levels, may more effectively suppress the parathyroid gland.

Parenteral aluminum compounds produce a local toxic myopathy in rats: importance of the anion

Aluminum lactate, injected in rats, produced skeletal muscle necrosis of diaphragm and abdominal wall subjacent to peritoneal surfaces. Deeper muscle cells (distal from inoculum) were less severely affected. Ultrastructural studies of diaphragm revealed inoculum coating collagen fibrils, aggregating next to muscle basal lamina and localized within phagocytes. Aluminum lactate penetrated lymphatic vessels and caused reactive changes on the pleural as well as peritoneal surfaces of diaphragm. In contrast, injection of aluminum citrate did not produce myopathy. Also, mixtures of aluminum lactate with aluminum citrate, sodium citrate, or another chelating agent failed to produce myopathy. Therefore, the regional myopathy produced by the lactate salt provides a model for in vivo cytotoxicity of aluminum in which anionic binding is a critical determinant.