CTLA4 Immunoglobulin but Not Anti-Tumor Necrosis Factor Therapy Promotes Staphylococcal Septic Arthritis in Mice

J Infect Dis. 2015 Oct 15;212(8):1308-16. doi: 10.1093/infdis/jiv212. Epub 2015 Apr 2.


Background: The development of biologics has greatly increased the quality of life and the life expectancy of many patients with rheumatoid arthritis. However, a large number of these patients have an increased risk of developing serious infections. The aim of this study was to examine differential effects of anti-tumor necrosis factor (TNF) treatment and CTLA4 immunoglobulin (Ig) treatment on both immunological response and host defense in a murine model of septic arthritis.

Methods: Abatacept (CTLA4-Ig), etanercept (anti-TNF), or phosphate-buffered saline were given to NMRI mice intravenously inoculated with Staphylococcus aureus. The clinical course of septic arthritis and histopathological and radiological changes of joints were compared among the groups.

Results: Mice receiving CTLA4-Ig treatment had more-severe septic arthritis, compared with controls and mice receiving anti-TNF treatment. Anti-TNF treatment led to more-severe weight loss and kidney abscesses, as well as a higher bacterial burden in the kidneys. Mice receiving CTLA4-Ig therapy had lower serum levels of interleukin 4, whereas mice receiving anti-TNF therapy had higher levels of TNF-α. Both iNOS and arginase-1 expression were reduced in peritoneal macrophages from mice receiving CTLA4-Ig, compared with expression in the anti-TNF group.

Conclusions: CTLA4-Ig therapy significantly increased the susceptibility to S. aureus septic arthritis in mice, whereas anti-TNF therapy deteriorated host bacterial clearance, resulting in more-severe weight loss and kidney abscesses.

Keywords: Staphylococcus aureus; abatacept; etanercept; mouse; septic arthritis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Abatacept / therapeutic use
  • Animals
  • Antirheumatic Agents / therapeutic use*
  • Arthritis, Infectious / immunology*
  • Arthritis, Infectious / microbiology
  • Arthritis, Rheumatoid / immunology*
  • Arthritis, Rheumatoid / microbiology
  • Etanercept / therapeutic use
  • Female
  • Joints / immunology
  • Joints / pathology
  • Mice
  • Staphylococcal Infections / immunology*
  • Staphylococcal Infections / microbiology
  • Staphylococcus aureus / immunology*
  • Tumor Necrosis Factor-alpha / immunology


  • Antirheumatic Agents
  • Tumor Necrosis Factor-alpha
  • Abatacept
  • Etanercept