Carcinoembryonic antigen in rheumatic diseases

Area of Science:

• Immunology
• Rheumatology
• Onco-immunology

Background:

• Previous studies indicated elevated plasma carcinoembryonic antigen (CEA) in seropositive rheumatoid arthritis (RA) patients compared to controls.
• CEA levels were not significantly different in seronegative RA, ankylosing spondylitis, or Still's disease patients compared to normal subjects.

Purpose of the Study:

• To investigate the association between CEA levels and autoimmune rheumatic diseases.
• To explore the source of elevated CEA in RA patients.

Main Methods:

• Plasma CEA levels were measured in patients with Sjögren's syndrome and Still's disease.
• Gel filtration was used to analyze CEA molecular weight in RA patients.
• CEA levels in rheumatoid synovial fluid and synovial membranes were assessed.

Main Results:

• Significantly higher mean CEA levels were observed in Sjögren's syndrome patients compared to normal controls (P=0.001).
• CEA in RA patients had a similar molecular weight to CEA found in colon cancer.
• CEA levels were significantly higher in rheumatoid synovial fluids than in osteoarthrotic fluids.
• CEA was extracted from rheumatoid synovial membranes but not normal synovium.

Conclusions:

• Elevated plasma CEA is associated with Sjögren's syndrome and seropositive RA.
• The inflamed rheumatoid synovium is a potential source of CEA in RA patients.
• CEA levels do not correlate with rheumatoid factor titers in RA.