The detection of specific IgA antibodies against Campylobacter jejuni is used to:
- Document recent or recurrent infection, particularly in patients with persistent or relapsing diarrhea.
- Support the diagnosis of chronic or delayed immune-mediated complications, such as:
- Guillain-Barré syndrome (GBS)
- Reactive arthritis
IgA antibodies are markers of the mucosal immune response, reflecting exposure at the intestinal level and possible ongoing immune activation.
The Campylobacter genus includes more than 20 bacterial species, with Campylobacter jejuni and Campylobacter coli being the most common in human infections. Transmission usually occurs via:
- Consumption of contaminated food, especially undercooked poultry and unpasteurized dairy products
- Ingestion of contaminated water
- Poorly cooked meat
Clinical Presentation
- Acute gastroenteritis with fever, abdominal cramps, diarrhea (often bloody), myalgia, headache, and fatigue.
- Illness typically lasts 1 to 7 days, but 5–10% of patients may experience relapses.
- In rare cases, the infection can lead to autoimmune complications, such as Guillain-Barré syndrome or reactive arthritis.
Diagnostic Importance of IgA Testing
While stool cultures are helpful during the acute phase of infection, they are often negative when immune complications arise. In such cases, detection of IgA antibodies can:
- Provide evidence of recent or ongoing infection, even when the microorganism is no longer detectable.
- Support diagnosis in post-infectious syndromes, where establishing a prior Campylobacter infection is crucial.
