Arvo building, auditorium F114, address: Arvo Ylpön katu 34.
Doctoral defence of Lic.Med. Pilvi Laurikka
The field of science of the dissertation is Internal Medicine.
The opponent is professor Martti Färkkilä (University of Helsinki). Professor Katri Kaukinen acts as the custos.
The language of the dissertation defence is Finnish.
Persistent symptoms in coeliac disease
Coeliac disease is a chronic disease in which dietary gluten leads to the destruction of small-intestinal mucosa in susceptible individuals. The disease may manifest as various gastrointestinal symptoms or as symptoms outside the intestine. The only available treatment is a lifelong and strict gluten-free diet. This means the exclusion of wheat, rye, barley, and products with added gluten from the diet.
Initiation of dietary treatment usually alleviates the symptoms rapidly. However, the long-term response of the gluten-free diet is not well-known. It seems that many treated coeliac disease patients may suffer from persistent gastrointestinal symptoms. Globally, the most common cause of poor symptom relief is ongoing gluten consumption. Other reasons include for example other gastrointestinal diseases or rarely, cancer. Nevertheless, in many patients the reason for symptoms remains unknown. Certain changes in the small-intestinal mucosa and for example small-intestinal microbes have been suggested to play a role in untreated coeliac disease. However, these issues have not been investigated in treated coeliac disease patients.
The aim of this dissertation was to investigate the prevalence and severity of gastrointestinal symptoms in treated coeliac disease patients, and to elucidate the reasons of persistent gastrointestinal symptoms. This was done by comparing the background, composition of intestinal microbiota and diet, and changes in the small-intestinal mucosa and microbial composition in treated coeliac patients with and without gastrointestinal symptoms. In addition, predictors for reduced quality of life in coeliac disease patients were investigated.
The result showed that symptoms were alleviated after patients began gluten-free diet, yet short-term treated patients had excessive diarrhoea. Almost a quarter of the long-term treated patients had persistent gastrointestinal symptoms compared with healthy controls, heartburn being the most frequent symptom. The symptoms of coeliac disease patients were considered mild to moderate compared with other gastrointestinal diseases. A long diagnostic delay, severe symptoms before diagnosis and the presence of thyroid disease, other gastrointestinal disease, food intolerance or any coeliac disease-associated comorbidity increased the risk of persistent symptoms. Furthermore, a long diagnostic delay, current gastrointestinal symptoms and psychiatric illness increased the risk of a reduced health-related quality of life. In further investigations it was shown that treated coeliac disease patients with ongoing gastrointestinal symptoms have different intestinal microbiota composition compared with asymptomatic patients. Additionally, the treated coeliac patients with persistent symptoms were shown to have a significantly lower intake of fibre than asymptomatic patients.
The results of this dissertation show that persistent gastrointestinal symptoms are common in coeliac disease patients on a long-term gluten-free diet. Some symptoms may require long-term dietary treatment before alleviation, which should be taken into account by physicians treating coeliac disease patients. The findings also support the hypothesis that a low fibre intake and alterations in the intestinal microbiota may play a role in poor symptom response. The causality of these issues with respect to symptoms should be further investigated. Based on the present study, it seems that changes in the immune activation does not have a role in the development of persistent symptoms.
The dissertation is published in the publication series of Acta Universitatis Tamperensis; 2339, Tampere University Press, Tampere 2017. The dissertation is also published in the e-series Acta Electronica Universitatis Tamperensis; 1844, Tampere University Press 2017.