Incidence and Characteristics of Autoimmune Hepatitis.
OBJECTIVE
Autoimmune hepatitis (AIH) is a progressive inflammatory liver disease of unknown etiology, with limited population-based estimates of pediatric incidence. We reported the incidence of pediatric AIH in Canada and described its clinical characteristics.


METHODS
We conducted a retrospective cohort study of patients aged <18 years diagnosed with AIH between 2000-2009 at all pediatric centers in Canada.


RESULTS
A total of 159 children with AIH (60.3% female, 13.2% type 2 AIH) were identified. Annual incidence was 0.23 per 100000 children. Median age at presentation for type 1 was 12 years (interquartile range: 11-14) versus 10 years for type 2 (interquartile range: 4.5-13) (P = .03). Fatigue (58%), jaundice (54%), and abdominal pain (49%) were the most common presenting symptoms. Serum albumin (33 vs 38 g/L; P = .03) and platelet count (187 000 vs 249 000; P <.001) were significantly lower and the international normalized ratio (1.4 vs 1.2; P <.001) was higher in cirrhotic versus noncirrhotic patients. Initial treatment included corticosteroids (80%), azathioprine (32%), and/or cyclosporine (13%). Response to treatment at 1 year was complete in 90%, and partial in 3%. 3% of patients had no response, and 3% responded and later relapsed. Nine patients underwent liver transplantation, and 4 patients died at a mean follow-up of 4 years.


CONCLUSIONS
AIH is uncommon in children and adolescents in Canada. Type 1 AIH was diagnosed 5.5 times more frequently than type 2 AIH. Most patients respond well to conventional therapy, diminishing the need for liver transplantation.
University of Ottawa and Children's Hospital of Eastern Ontario, Ottawa, Ontario, Canada; cajimenez@cheo.on.ca.
Carolina
C
Jiménez-Rivera
University of Toronto and The Hospital for Sick Children, Toronto, Ontario, Canada;
Simon C
SC
Ling
McGill University and Montreal Children's Hospital, Montreal, Quebec, Canada;
Najma
N
Ahmed
University of Alberta and Stollery Children's Hospital, Edmonton, Alberta, Canada;
Jason
J
Yap
University of Ottawa and Children's Hospital of Eastern Ontario, Ottawa, Ontario, Canada;
Mary
M
Aglipay
University of Ottawa and Children's Hospital of Eastern Ontario, Ottawa, Ontario, Canada;
Nick
N
Barrowman
University of Ottawa and Children's Hospital of Eastern Ontario, Ottawa, Ontario, Canada;
Samantha
S
Graitson
Memorial University of Newfoundland and Janeway Children's Hospital, St. John's, Newfoundland, Canada;
Jeff
J
Critch
Dalhousie University and IWK Health Center, Halifax, Nova Scotia, Canada;
Mohsin
M
Rashid
University of Toronto and The Hospital for Sick Children, Toronto, Ontario, Canada;
Vicky L
VL
Ng
University of Toronto and The Hospital for Sick Children, Toronto, Ontario, Canada;
Eve A
EA
Roberts
McMaster University and McMaster Children's Hospital, Hamilton, Ontario, Canada;
Herbert
H
Brill
McMaster University and McMaster Children's Hospital, Hamilton, Ontario, Canada;
Jenna K
JK
Dowhaniuk
University of Saskatchewan and Children's Hospital of Saskatchewan, Saskatoon, Saskatchewan, Canada;
Garth
G
Bruce
University of Western Ontario and London Health Science Center, London, Ontario, Canada;
Kevin
K
Bax
University of Manitoba and The Children's Hospital of Winnipeg, Winnipeg, Manitoba, Canada;
Mark
M
Deneau
University of British Columbia and BC Children's Hospital, Vancouver, British Columbia, Canada;
Orlee R
OR
Guttman
University of British Columbia and BC Children's Hospital, Vancouver, British Columbia, Canada;
Richard A
RA
Schreiber
University of Calgary and Alberta Children's Hospital Calgary, Alberta, Canada; and.
Steven
S
Martin
University of Montreal and Centre Hospitalier Universitaire Sainte-Justine, Montreal, Quebec, Canada.
Fernando
F
Alvarez
D000293:Adolescent; D000305:Adrenal Cortex Hormones / Q000627:therapeutic use; D001379:Azathioprine / Q000627:therapeutic use; D002170:Canada / Q000453:epidemiology; D002648:Child; D049448:Cholangiopancreatography, Magnetic Resonance; D016572:Cyclosporine / Q000627:therapeutic use; D005260:Female; D019693:Hepatitis, Autoimmune / Q000175:diagnosis* / Q000453:epidemiology* / Q000401:mortality / Q000601:surgery / Q000628:therapy; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D015994:Incidence; D008103:Liver Cirrhosis / Q000453:epidemiology; D016031:Liver Transplantation; D008297:Male; D012189:Retrospective Studies; D016019:Survival Analysis; D016896:Treatment Outcome
D000305:Adrenal Cortex Hormones; D007166:Immunosuppressive Agents; D016572:Cyclosporine; D001379:Azathioprine