Danish cohort of monozygotic inflammatory bowel disease twins: Clinical characteristics and inflammatory activity.
OBJECTIVE
To describe the establishment of a Danish inflammatory bowel diseases (IBD) twin cohort with focus on concordance of treatment and inflammatory markers.


METHODS
We identified MZ twins, likely to be discordant or concordant for IBD, by merging information from the Danish Twin Register and the National Patient Register. The twins were asked to provide biological samples, questionnaires, and data access to patient files and public registries. Biological samples were collected via a mobile laboratory, which allowed for immediate centrifugation, fractionation, and storage of samples. The mean time from collection of samples to storage in the -80 °C mobile freezer was less than one hour. The diagnoses where validated using the Copenhagen diagnostic criteria.


RESULTS
We identified 159 MZ IBD twin pairs, in a total of 62 (39%) pairs both twins agreed to participate. Of the supposed 62 IBD pairs, the IBD diagnosis could be confirmed in 54 pairs. The cohort included 10 concordant pairs, whereof some were discordant for either treatment or surgery. The 10 concordant pairs, where both pairs suffered from IBD, included eight CD/CD pairs, one UC/UC pair and one UC/IBDU pair. The discordant pairs comprised 31 UC, 5 IBDU (IBD unclassified), and 8 CD discordant pairs. In the co-twins not affected by IBD, calprotectin was above 100 μg/g in 2 participants, and above 50 μg/g in a further 5 participants.


CONCLUSIONS
The presented IBD twin cohorts are an excellent resource for bioinformatics studies with proper adjustment for disease-associated exposures including medication and inflammatory activity in the co-twins.
Frederik Trier Moller, Lina Knudsen, Vibeke Andersen, Research Unit for Molecular Diagnostics, Hospital of Southern Jutland, 6200 Aabenraa, Denmark.
Frederik Trier
FT
Moller
Frederik Trier Moller, Lina Knudsen, Vibeke Andersen, Research Unit for Molecular Diagnostics, Hospital of Southern Jutland, 6200 Aabenraa, Denmark.
Lina
L
Knudsen
Frederik Trier Moller, Lina Knudsen, Vibeke Andersen, Research Unit for Molecular Diagnostics, Hospital of Southern Jutland, 6200 Aabenraa, Denmark.
Marcus
M
Harbord
Frederik Trier Moller, Lina Knudsen, Vibeke Andersen, Research Unit for Molecular Diagnostics, Hospital of Southern Jutland, 6200 Aabenraa, Denmark.
Jack
J
Satsangi
Frederik Trier Moller, Lina Knudsen, Vibeke Andersen, Research Unit for Molecular Diagnostics, Hospital of Southern Jutland, 6200 Aabenraa, Denmark.
Hannah
H
Gordon
Frederik Trier Moller, Lina Knudsen, Vibeke Andersen, Research Unit for Molecular Diagnostics, Hospital of Southern Jutland, 6200 Aabenraa, Denmark.
Lene
L
Christiansen
Frederik Trier Moller, Lina Knudsen, Vibeke Andersen, Research Unit for Molecular Diagnostics, Hospital of Southern Jutland, 6200 Aabenraa, Denmark.
Kaare
K
Christensen
Frederik Trier Moller, Lina Knudsen, Vibeke Andersen, Research Unit for Molecular Diagnostics, Hospital of Southern Jutland, 6200 Aabenraa, Denmark.
Tine
T
Jess
Frederik Trier Moller, Lina Knudsen, Vibeke Andersen, Research Unit for Molecular Diagnostics, Hospital of Southern Jutland, 6200 Aabenraa, Denmark.
Vibeke
V
Andersen
D000328:Adult; D000368:Aged; D000893:Anti-Inflammatory Agents / Q000627:therapeutic use; D015415:Biomarkers / Q000032:analysis; D001706:Biopsy; D016022:Case-Control Studies; D015331:Cohort Studies; D003082:Colectomy; D003093:Colitis, Ulcerative / Q000175:diagnosis / Q000235:genetics / Q000378:metabolism / Q000628:therapy; D003424:Crohn Disease / Q000175:diagnosis / Q000235:genetics / Q000378:metabolism / Q000628:therapy; D003718:Denmark; D004200:Diseases in Twins / Q000175:diagnosis / Q000235:genetics / Q000378:metabolism / Q000628:therapy; D016099:Endoscopy, Gastrointestinal; D005260:Female; D005765:Gastrointestinal Agents / Q000627:therapeutic use; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D039841:Leukocyte L1 Antigen Complex / Q000032:analysis; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D012042:Registries; D012720:Severity of Illness Index; D014430:Twins, Monozygotic / Q000235:genetics; D015854:Up-Regulation
D000893:Anti-Inflammatory Agents; D015415:Biomarkers; D005765:Gastrointestinal Agents; D007166:Immunosuppressive Agents; D039841:Leukocyte L1 Antigen Complex
Biobank; Crohn’s disease; Digestive system diseases; Epidemiologic studies; Inflammatory bowel diseases; Twins; Ulcerative colitis