Christian Børde Arkteg

Avhandlingen er tilgjengelig her! The doctoral thesis! Auditoriet er åpent for publikum, men disputasen vil også bli strømmet her.  Opptak av disputasen vil være tilgjengelig i et døgn. Auditoriet er åpent for publikum. The defense will still be streamed here.  A recording of the disputation will be available for 24 hours.  The auditorium is open to the public.   Prøveforelesning over oppgitt emne holdes kl. 10.15, samme sted:  “Implications of -omics research in inflammatory bowel disease” Prøveforelesningen vil også bli strømmet/the trail lecture will also be streamed

Populærvitenskapelig sammendrag av avhandlingen: 
Ulcerative Colitis (UC) is a chronic, inflammatory disease of the colon that has a relapsing-remitting characteristic. The disease management consists of prolonging periods of remission and reducing relapse frequency. There is currently no universally accepted definition of remission in UC. There are different methods of establishing if a patient is in remission, but the lack of definition and knowledge make it difficult to know which method to use. The majority of these methods are poorly described for remission patients representing a substantial knowledge gap.

This thesis explored the remission term by investigating the mucosal transcriptional profile in UC remission patients and the utility of histology and transcripts as evaluation modalities. The project was a part of the Advanced Study of Inflammatory Bowel disease (ASIB) prospective study at the University Hospital of Northern Norway, Tromsø. All patients were recruited from August 2013 to April 2016, and they have given written consent to participate in the study.

We found that several of the gene transcripts investigated were differently expressed in UC remission patients in comparison to healthy controls. These genes were largely related to pro-inflammatory mechanisms and barrier dysfunction, indicating that despite an apparent normal mucosa in endoscopy, the mucosa differed on a transcriptional level. We then investigated if histology could detect inflammation and consistently classify a patient as in remission using the different scoring indices. The results showed that histology could detect inflammation invisible to the naked eye, but the histologic scores varied too much to be accurate in a categorical classification. The main source of variance was the histologic raters. Lastly, we investigated if any of the clinical, endoscopic, histologic, or transcriptional variables could predict impending relapse. The results showed that patients with a low ratio between two transcripts had 5.3 times higher risk of relapse. Histologic factors did not turn out to be predictive of relapse. Clinical and endoscopic factors were promising but ultimately not significant, possibly hindered by low pow er.

The conclusion was that several gene transcripts were differently regulated in UC remission patients compared to healthy controls. Some of these may be able to predict relapse and have potential use as biomarkers to improve the current treatment regimes. Histology might be used as an aid in tailored treatment but should not be used as a hard endpoint due to high variance. The transcript ratio must be further validated before implementation into clinical practice.

Hovedveileder
Førsteamanuensis Rasmus Goll, Institutt for klinisk medisin, Det helsevitenskapelige fakultet, UiT Norges arktiske universitet.

Biveiledere
Professor Jon Ragnar Florholmen, Institutt for klinisk medisin, Det helsevitenskapelige fakultet, UiT Norges arktiske universitet.

Overlege Mona Dixon Gundersen, Universitetssykehuset Nord-Norge.

Bedømmelseskomité
Dr. Med Jakob Benedict Seidelin, Klinik for mave‐, Tarm‐, og Leversygdomme. Herlev Hospital, Danmark - 1. opponent.

Ph.d. Petr Ricanek, Akershus Universitetssykehus, Oslo, Norway - 2. opponent.  

Professor Sigrid Brækkan, IKM, Det helsevitenskapelige fakultet, UiT Norges arktiske universitet – leder av komité.

Disputasleder
Førsteamanuensis Marit Dahl Solbu, Institutt for klinisk medisin, Det helsevitenskapelige fakultet, UiT Norges arktiske universitet.