Alteration of Chlamydia trachomatis biologic behavior in synovial membranes. Suppression of surface antigen production in reactive arthritis and Reiter's syndrome

Arthritis Rheum. 1995 Oct;38(10):1410-7. doi: 10.1002/art.1780381008.


Objective: To investigate the biologic state of Chlamydia and its surface antigen expression in the synovial membranes of patients with Chlamydia-associated reactive arthritis/Reiter's syndrome (ReA/RS).

Methods: Expression of chlamydial lipopolysaccharide (LPS), major outer membrane protein (MOMP), and elementary body (EB) antigens was studied by gold labeling immunoelectron microscopy on 6 synovial membrane and 2 synovial fluid (SF) pellet samples from 6 patients with Chlamydia-associated arthritis. The study findings were compared with 24-hour cultures of HeLa cells infected with Chlamydia trachomatis EB.

Results: Persistent C trachomatis infection was found in all 6 synovial membrane samples from patients who had either early or chronic arthritis. The infection persisted despite antibiotic treatment, including a 1-month course of doxycycline therapy. Most persistent organisms were atypical reticulate bodies (RBs) found in both fibroblasts and macrophages. Specific, but weak, immunogold staining for all 3 antibodies was found on both intracellular RBs and extracellular EBs. In the SF samples, Chlamydia surface antigens were detected only in phagosomes containing degraded electron-dense materials.

Conclusion: The synovial membrane biopsies conducted in this study of Chlamydia-associated ReA/RS revealed atypical RBs with diminished MOMP and LPS expression. Such altered organisms may escape immune surveillance and contribute to disease chronicity; moreover, these organisms may be difficult to detect and treat in some ReA/RS patients.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Antigens, Surface / analysis*
  • Arthritis, Reactive / immunology
  • Arthritis, Reactive / microbiology*
  • Bacterial Outer Membrane Proteins / analysis*
  • Chlamydia Infections / immunology
  • Chlamydia Infections / microbiology*
  • Chlamydia trachomatis / immunology*
  • Female
  • HeLa Cells
  • Humans
  • Lipopolysaccharides / analysis
  • Male
  • Microscopy, Immunoelectron
  • Middle Aged
  • Porins*
  • Prohibitins
  • Synovial Fluid / immunology
  • Synovial Fluid / microbiology
  • Synovial Membrane / immunology
  • Synovial Membrane / microbiology*


  • Antigens, Surface
  • Bacterial Outer Membrane Proteins
  • Lipopolysaccharides
  • PHB2 protein, human
  • Porins
  • Prohibitins
  • omp1 protein, Chlamydia trachomatis