Chlamydia influences local symptoms in IBD

Researchers in August's issue of the European Journal of Gastroenterology & Hepatology show that in Crohn's disease, inflamed tissue specimens contain more C. pneumonia DNA, and influences local clinical manifestations.

Chlamydia has been associated with autoimmune diseases.

However, a link between chlamydial infection and the etiopathogenesis of inflammatory bowel disease (IBD) remains controversial.

Dr Stefan Müller and colleagues assessed the relationship between chlamydial infection and IBD.

The team evaluated the association as evidenced by serological measurement and DNA analysis of mucosal biopsy specimens.

The sera of 78 patients with Crohn's disease, and 24 patients with ulcerative colitis were tested for anti-C. pneumonia.

The investigators also assessed 73 healthy family members, and 20 healthy controls for anti-C. pneumonia IgG titres.

C. pneumonia DNA was found in 27% in inflamed biopsy specimens of Crohn's patients

European Journal of Gastroenterology & Hepatology

A subgroup consisting of 13 ulcerative colitis and 39 Crohn's disease patients was screened for the presence of chlamydial DNA.

The patients were screened on 42 inflamed versus 30 non-inflamed biopsy specimens and for mutations of their NOD2/CARD15 gene.

The investigators found anti-C. pneumonia IgG antibodies in the sera of 41% of patients with Crohn's disease, and 46% of patients with ulcerative colitis.

The team observed that 48% of unaffected family members, and 45% unrelated healthy controls had anti-C pneumonia IgG antibodies in the sera.

The team noted that 35% of the control, 18% of Crohn's and 24% of ulcerative colitis biopsy specimens contained C. pneumonia DNA.

In Crohn's disease, however, C. pneumonia DNA was found in 27% in inflamed versus 8% of non-inflamed biopsy specimens.

The frequencies of NOD2/CARD15 mutations were 33% for Crohn's disease patients with C. pneumonia DNA.

The investigators found the genetic mutations in 47% for Crohn's disease patients without C. pneumonia DNA.

Dr Müller's team concludes, “We found no marked differences in respect to anti-C. pneumonia serum IgG or C. pneumonia DNA between healthy controls and patients with IBD.”

“However, in Crohn's disease patients, inflamed tissue specimens contained significantly more C. pneumonia DNA compared with biopsies from unaffected areas.”

“C. pneumonia is unlikely to be of pathogenic importance in IBD while it may still influence local clinical manifestations.”