Archaeoastronomy

Autoantibodies associated with Crohn's disease and ulcerative colitis

Anti–Saccharomyces cerevisiae antibodies (ASCA) are a type of autoantibody found in the blood of some individuals. These antibodies are directed against Saccharomyces cerevisiae, a species of yeast commonly used in baking and brewing. ASCA are primarily associated with inflammatory bowel disease (IBD), particularly Crohn's disease.

Background

Saccharomyces cerevisiae is a species of yeast that is widely used in the food industry. It is also a common component of the human diet. In some individuals, the immune system may produce antibodies against this yeast, leading to the presence of ASCA in the blood. The presence of ASCA is often used as a serological marker in the diagnosis of IBD.

Clinical Significance

ASCA are most commonly associated with Crohn's disease, a type of inflammatory bowel disease characterized by chronic inflammation of the gastrointestinal tract. The presence of ASCA can help differentiate Crohn's disease from ulcerative colitis, another form of IBD. While ASCA are more prevalent in Crohn's disease, they can also be found in a smaller percentage of patients with ulcerative colitis.

Diagnosis

The detection of ASCA is performed using enzyme-linked immunosorbent assay (ELISA) or immunofluorescence. These tests measure the levels of ASCA in the blood and can aid in the diagnosis of IBD. However, ASCA testing is not definitive on its own and is typically used in conjunction with other diagnostic methods, such as endoscopy and biopsy.

Prognostic Value

The presence of ASCA may have prognostic implications in Crohn's disease. Some studies suggest that patients with ASCA-positive Crohn's disease may have a more aggressive disease course, with increased risk of complications such as strictures and fistulas. However, the exact role of ASCA in predicting disease outcomes remains an area of ongoing research.

Pathophysiology

The exact mechanism by which ASCA are produced is not fully understood. It is hypothesized that a breakdown in the intestinal barrier may allow Saccharomyces cerevisiae antigens to interact with the immune system, leading to the production of antibodies. Genetic factors may also play a role, as certain genetic markers are associated with the presence of ASCA in patients with Crohn's disease.

Related pages

• Crohn's disease
• Ulcerative colitis
• Inflammatory bowel disease
• Autoantibody

Gallery

• 

  Saccharomyces cerevisiae under DIC microscopy

• 

  Candida albicans