Effects of Libby amphibole asbestos exposure on two models of arthritis in the Lewis rat

J Toxicol Environ Health A. 2012;75(6):351-65. doi: 10.1080/15287394.2012.668164.

Abstract

Epidemiological data suggest that occupational exposure to the amphibole-containing vermiculite in Libby, MT, was associated with increased risk for developing autoimmune diseases and had an odds ratio of 3.23 for developing rheumatoid arthritis (RA). The collagen-induced arthritis (CIA) and the peptidoglycan-polysaccharide (PG-PS) models of RA were employed to determine whether exposure to Libby amphibole (LA) induced a more rapid onset, increased expression, or prolonged course of RA. Female Lewis rats were intratracheally instilled with total doses of 0.15, 0.5, 1.5, or 5 mg LA or 0.5 or 1.5 mg amosite asbestos, and arthritis was induced with either the PG-PS or CIA model. Neither LA nor amosite exposure affected the disease course in the CIA model, or the production of rheumatoid factor (RF) or anti-cyclic citrullinated peptide (CCP) antibodies. LA exposure reduced swelling in the PG-PS model and decreased anti-PG-PS and total immunoglobulin M (IgM) antibody titers. Both amosite and LA exposure increased the number of rats with circulating anti-nuclear antibodies (ANA), the majority of which presented a speckled staining pattern. However, this ANA enhancement was not dose responsive. These results failed to show a positive correlation between LA exposure and RA disease in two animal models, although upregulated ANA suggest an altered immunological profile consistent with other systemic autoimmune diseases.

MeSH terms

  • Aluminum Silicates / chemistry
  • Animals
  • Antibodies / blood
  • Arthritis, Experimental / chemically induced*
  • Arthritis, Rheumatoid / chemically induced*
  • Asbestos, Amphibole / administration & dosage
  • Asbestos, Amphibole / toxicity*
  • Biomarkers
  • Dose-Response Relationship, Drug
  • Female
  • Immunoglobulin G / blood
  • Injections, Spinal
  • Joints / pathology
  • Lung Diseases / chemically induced
  • Lung Diseases / pathology
  • Rats
  • Rats, Inbred Lew
  • Time Factors

Substances

  • Aluminum Silicates
  • Antibodies
  • Asbestos, Amphibole
  • Biomarkers
  • Immunoglobulin G
  • vermiculite