A normal GI tract biopsy does not protect against subsequent inflammatory bowel disease

Study participants

The researchers used a national database of reports of tissue samples from the gut between 1965 and 2016, and thus identified more than 200,000 individuals with normal biopsy and about 250,000 individuals with normal mucosa from the upper digestive tract. They also identified more than 2 million matched control subjects from the population, and nearly half a million siblings of subjects with tissue samples across a multigenerational registry.

Follow-up and results

During a 10-year follow-up period, 4853 individuals (2.4%) with a normal intestinal biopsy were diagnosed with IBD, compared with 0.4% of the control group. This corresponds to one additional case of IBD for every 37 people followed for 30 years after a normal GI tract was screened. Compared to controls, subjects with a normal tissue sample from the colon (the lower part of the intestine) had an increased risk of inflammatory bowel disease (HR = 5.56; 95% CI: 5.28–5.85), but also of the ulcerative colitis subgroup (HR = 5.20). ; (95% CI: 4.85-5.59) and Crohn’s disease (HR = 6.99 (95% CI: 6.38-7.66). Even compared with siblings, the risk of IBD and its subgroups was high among people whose intestines were examined but who had a normal tissue sample. The study had some limitations including that the researchers didn’t have data on why the intestinal tissue samples were taken (most likely due to gastrointestinal symptoms), the patients’ lifestyle, how they felt otherwise, and genetic risk factors for IBD.

Clinical implications

“A normal bowel tissue sample has been linked to an increased risk of inflammatory bowel disease for at least 30 years after screening. This may indicate that some patients with IBD have had symptoms for many years before diagnosis and that investigation of gastrointestinal symptoms is incomplete,” says Dr. says the first author Jianghui Sun in the Department of Medical Epidemiology and Biostatistics at Karolinska Institutet.

Another author prof Jonas F Ludwigson At the same institution, he adds, “Carers should be aware of the increased long-term risk of developing IBD in patients with gastrointestinal symptoms even when endoscopy shows that the mucosa is normal.”

The study was funded by the Swedish Research Council, FORTE, Karolinska Institutet, and the Chinese Grants Board. Funders had no role in study design, data collection or analysis, publication decisions, or in the work of the manuscript.

Publishing

Sun J, Fang F, Olén O, Song M, Halfvarson J, Roelstraete B, Khalili H, Ludvigsson JF. Long-term risk of developing inflammatory bowel disease after endoscopic biopsy with normal mucosa: a cohort, population-based, sibling-controlled study in Sweden. Plus Med. 2023 Feb 23; 20 (2): e1004185. doi: 10.1371/journal.pmed.1004185. PMID: 36821532.