Does aluminium have a pathogenic role in dialysis associated arthropathy?

Aluminium and Alzheimer's disease

The hypothesis that aluminium (Al) is a cause of (or a risk factor in) the development of beta-amyloid plaques and neurofibrillary tangles (NFT) and dementia in Alzheimer's disease (AD) is based on studies by Wisniewski et al, Klatzo et al and Terry & Peña in 1965 that showed that injection of experimental animals with Al compounds induces the formation of NFT. Other publications revealed that Al affects cognitive functions in experimental animals and humans undergoing dialysis for renal failure. Electron probe and laser microprobe mass analysis (LAMMA) studies have demonstrated the presence of Al in NFT and cores of amyloid stars and nuclei of neurons in AD patients. Other studies have indicated the association between amyotrophic lateral sclerosis/Guam parkinsonism-dementia complex and Al in the environment. A recent report suggests that the chelating agent desferrioxamine slows the rate of cognitive decline in AD patients. Extensive studies of the pathology of AD and Al-induced encephalopathy by our group and others indicate that Al does not cause Alzheimer's disease neuropathology. However, under certain conditions, cognition can be affected when Al enters the brain. Therefore, for individuals with renal failure or undergoing dialysis or individuals with a damaged blood-brain barrier, the intake of Al should be controlled.

Beta 2-microglobulin amyloid deposition in hip revision arthroplasty tissues

AIMS

Hip joint disease associated with progressive amyloid deposition in uraemic patients receiving chronic haemodialysis treatment often requires treatment by joint arthroplasty. The aim of this study was to determine whether beta 2-microglobulin amyloid deposition occurred in the periprosthetic tissues of arthroplasties that had undergone aseptic loosening and required a revision procedure.

METHODS AND RESULTS

Sections of the pseudocapsule, acetabular and femoral pseudomembrane surrounding failed total hip replacements of five uraemic patients known to have beta 2-microglobulin amyloid deposits at the time of primary joint replacement were examined for the presence of beta 2-microglobulin amyloid deposition by Congo red staining and immunohistochemical staining for beta 2-microglobulin and other amyloid proteins. Clinical and radiological features of each case, including postoperative history and extent of osteolysis, were also noted. In all cases evidence of beta 2-microglobulin amyloid deposits were found in one or more of the above periprosthetic tissues. In three of these cases amyloid deposition was extensive.

CONCLUSIONS

This study shows that beta 2-microglobulin amyloid deposition occurs in revision arthroplasty tissues. Accelerated loosening of the prosthesis is known to occur in uraemic patients and it is possible that beta 2-microglobulin amyloid deposition may contribute to early arthroplasty failure in uraemic patients who remain on haemodialysis treatment.

Effect of aluminum on superoxide dismutase activity in the adult rat brain

Male rats were treated daily with an intraperitoneal injection of 15 mg aluminum (Al chloride)/kg body weight for 17 d, in order to study the effects on superoxide dismutase (SOD) activities in the brain (cortex). No significant difference between control and treated animals was registered in the Cu/Zn and Mn SOD activities in the gray matter of the cortex. High Al levels were found in the plasma, the spleen, and the liver of the treated animals in comparison to the controls, but not in the cortex homogenates (gray matter). In addition, Al induced a significant decrease in food ingestion and weight gain.

Aluminum chelation: chemistry, clinical, and experimental studies and the search for alternatives to desferrioxamine

This review focuses on aluminum (Al) chelation, its chemistry and biology. The toxicology and biology of Al in mammalian organisms are briefly reviewed to introduce the problems associated with excessive Al exposure and accumulation and the challenges facing an effective Al chelator. The basics of Al chelation chemistry are considered to help the reader understand the Al chelation chemical literature. The chemical properties of Al enable prediction of effective functional groups for Al chelation. A compilation of distribution coefficients between octanol and aqueous phases (Do/a) for chelators and their complexes with Al shows the effect of complexation on lipophilicity. A compilation of stability constants for Al.chelator complexes illustrates the role of oxygen in ligands that form stable complexes. The history of clinical Al chelation therapy is reviewed, with emphasis on desferrioxamine (DFO), which has been extensively used since 1980. The beneficial and adverse effects and limitations of DFO use in end-stage renal-diseased patients, in patients with neurodegenerative disorders, including Alzheimer's disease, and in animal models of Al intoxication are presented. The methods to evaluate potential Al chelators in vitro, in vivo, and using computer modeling are discussed. The Al chelation literature is reviewed by the chemical class of chelators, including fluoride, carboxylic acids, amino acids, catechols, polyamino carboxylic acids, phenyl carboxylic acids, the hydroxypyridinones, and hydroxamic acids.

Some commonly unrecognized manifestations of metabolic arthropathies

The metabolic arthropathies are characterized by the deposition of abnormal substances in or around joints. Certain features of some of these arthropathies and their significance have only recently been recognized and others have been insufficiently emphasized. An important group of conditions are the arthropathies related to renal failure and its treatment, namely, aluminum toxicity, periarticular calcification and crystal deposition, hyperparathyroidism, and dialysis-related amyloidosis. Crystal deposition diseases, specifically, gouty arthritis, calcium pyrophosphate deposition, and calcium hydroxyapatite deposition, are also reviewed.