Genetic distinctions between autoimmune hepatitis in Italy and North America.
OBJECTIVE
Our goals were to analyze the known genetic predispositions for autoimmune hepatitis (AIH) in AIH Italian population and to compare them with North American counterparts.


METHODS
Human leukocyte antigens (HLA) B8, C7, DR3, DR4, DR7, DR11, DR13, DQ2 and the B8-DR3-DQ2 phenotype were determined by microlymphocytotoxicity and polymerase chain reaction in 74 Italian patients (57 with type 1 and 17 with type 2 AIH) and 149 North American patients with type 1 AIH, and in adequate controls.


RESULTS
B8-DR3-DQ2 occurred more frequently in Italian patients with type 1 AIH than in Italian controls (30% vs 7%, P<0.0001), but less frequently than in North American counterparts (30% vs 48%, P = 0.02). DR4 occurred less frequently in Italian patients with type 1 AIH (23% vs 43%, P = 0.01) and in controls (16% vs 34%, P = 0.0003) than in North American counterparts. No differences were found in alleles' frequency between type 1 and type 2 Italian AIH patients. DR11 had a frequency lower in type 1 Italian AIH patients than controls (17% vs 35%, P = 0.01).


CONCLUSIONS
HLA DR4 is not associated with AIH in Italy. The known HLA risk factors for AIH occur similarly in Italian patients with type 1 and type 2 AIH, and they are less frequent than in North American patients. B8-DR3-DQ2 is the predominant phenotype of type 1 AIH also in Italy, and HLA DR11 may be a regionally distinctive protective factor against type 1 AIH.
Muratori
Paolo
P
Dipartimento di Medicina Interna, Cardioangiologia, Epatologia Policlinico S.Orsola-Malpighi, via Massarenti, 9, 40138 Bologna, Italy. paolomuratori@tin.it
Czaja
Albert-J
AJ
Muratori
Luigi
L
Pappas
Georgios
G
Maccariello
Silvana
S
Cassani
Fabio
F
Granito
Alessandro
A
Ferrari
Rodolfo
R
Mantovani
Vilma
V
Lenzi
Marco
M
Bianchi
Francesco-B
FB
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D005260:Female; D020022:Genetic Predisposition to Disease; D006680:HLA Antigens / Q000235:genetics*; D019693:Hepatitis, Autoimmune / Q000453:epidemiology* / Q000235:genetics*; D006801:Humans; D007558:Italy / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009656:North America / Q000453:epidemiology; D012307:Risk Factors
D006680:HLA Antigens