| 1. |
- Rendek, Zlatica, 1983-
(författare)
-
Faecal Calprotectin Diagnostics : Focus on Primary Care and Suspected Sources of Error
- 2023
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Patients with gastrointestinal symptoms often present a diagnostic challenge for general practitioners. Faecal calprotectin (FC) is commonly used as a marker of intestinal inflammation and is useful for differentiating between inflammatory bowel disease (IBD) and irritable bowel syndrome (IBS), as well as for the follow-up of patients with IBD and monitoring treatment response. However, several other causes of increased FC levels have been acknowledged, including intake of non-steroidal anti-inflammatory drugs or proton pump inhibitors and respiratory infections. Currently, there is insufficient knowledge about how these factors affect FC levels. It is crucial that physicians who use calprotectin as a diagnostic tool have the ability to conduct a sound evaluation of the test result to ensure accurate clinical decisions, and potentially avoid unnecessary referrals and invasive investigations.The aim of this thesis was to investigate the contribution of FC in the diagnostics of gastrointestinal disease in primary care, its diagnostic value and accuracy as a predictor of gastrointestinal disease and the influence of different sources of error on calprotectin levels. In particular, the effects of oral diclofenac (a non-steroidal anti-inflammatory drug [NSAID]), omeprazole (a proton pump inhibitor [PPI]) and respiratory tract infection on FC levels are investigated. The normalization interval after cessation of diclofenac and omeprazole is assessed.The first study is a retrospective analysis of data on all FC tests on adults conducted in primary care in Östergötland County in 2010. A higher proportion of patients with a positive FC result were diagnosed with IBD and organic gastrointestinal disease compared with those with a negative FC result. Predictors of IBD were positive FC, diarrhoea, rectal bleeding and male sex. Predictors of organic gastrointestinal disease were found to be positive FC, age >35 years, abnormal clinical findings and duration <3 months. FC had the highest sensitivity and negative predictive value compared with demographic factors, symptoms and duration. Intake of NSAIDs, PPIs and acetyl salicylic acid showed marginal effects on the diagnostic accuracy of FC for IBD and organic gastrointestinal disease. Among patients with a negative FC test, on whom no further investigations were performed, no missed diagnoses of IBD or organic gastrointestinal disease were detected at a 5-year follow-up.The second study investigates the effect of diclofenac intake on FC levels. We found that shortterm intake of oral diclofenac was associated with increased FC levels and that FC returned to normal within 2 weeks of cessation.The third study reports on a randomized open-label clinical trial and investigates the effect of omeprazole, diclofenac and co-administration of these drugs on FC levels. The findings regarding diclofenac were consistent with those of the second study. Short-term intake of omeprazole alone or when co-administered with diclofenac was associated with increased FC levels. The normalization interval was 3 weeks after cessation.The fourth study, a prospective cohort study, examines the effect of an acute respiratory tract infection on the FC level. Faecal and salivary calprotectin levels were not found to be increased during respiratory tract infections. This study did not confirm any correlation between calprotectin levels in saliva and faeces during infection.In conclusion, FC reliably rules out IBD and contradicts the presence of other organic gastrointestinal diseases in patients with gastrointestinal symptoms attending primary care. Patients with a positive FC test together with other symptoms, such as diarrhoea, rectal bleeding, short duration or age >35 years should be prioritized for further investigations. Short-term intake of diclofenac, omeprazole, or their co-administration in healthy individuals is associated with increased FC levels. In patients with an increased FC level on diclofenac, it is sufficient to repeat the FC test 2 weeks after cessation. In patients on omeprazole alone or when co-administered with diclofenac, the FC test should be repeated 3 weeks after cessation. Acute respiratory tract infections were not found to be associated with increased faecal or salivary calprotectin levels.
|
|
