Anti-neutrophil cytoplasmic antibodies in type 1 and 2 autoimmune hepatitis.
Perinuclear anti-neutrophil cytoplasmic antibodies (pANCA) have been recently defined as the most sensitive autoantibody of type 1 autoimmune hepatitis (AIH-1). Their prevalence in type 2 autoimmune hepatitis (AIH-2) has not yet been evaluated. The aim of the present study was to verify the association of pANCA with AIH-1 in an Italian series and to investigate the prevalence of the antibodies in AIH-2 and in proper control groups represented by cases of chronic hepatitis C (CH-C) with similar autoimmune features. pANCA were found in 30 of 46 (65%) AIH-1 and in 4 of 30 (13%) ANA/smooth muscle antibody (SMA) positive CH-C (P = .0000006). Nineteen AIH-2, 29 liver kidney microsomal antibody type 1/liver cytosol antibody type 1 (LKM1/LC1) positive CH-C cases and 50 healthy controls were all negative. In AIH-1, pANCA were significantly (P = .009) more frequent in males (8 of 9, 89%) than in females (22 of 37, 59%). All pANCA positive sera showed SMA of the antiactin type. The present data confirm that pANCA, although less prevalent in our series than in other reports, do associate with AIH-1 also in the Mediterranean area and show that it can identify a small subgroup (13%) of ANA/SMA positive chronic hepatitis C, in which autoimmune reactions might play a more relevant role than viral infection. They also show the antibodies are absent in AIH-2. In conclusion, pANCA appear to be mutually exclusive of LKM1 positivity, either hepatitis C virus-related or not, thus representing a further valuable tool to differentiate the two types of autoimmune hepatitis.
Zauli
D
D
Cattedra di Allergologia ed Immunologia Clinica, University of Bologna, Italy.
Ghetti
S
S
Grassi
A
A
Descovich
C
C
Cassani
F
F
Ballardini
G
G
Muratori
L
L
Bianchi
F B
FB
D000293:Adolescent; D000328:Adult; D000368:Aged; D019268:Antibodies, Antineutrophil Cytoplasmic / Q000097:blood / Q000276:immunology*; D001324:Autoantigens / Q000276:immunology; D001327:Autoimmune Diseases / Q000097:blood / Q000453:epidemiology / Q000276:immunology*; D002648:Child; D005260:Female; D006505:Hepatitis / Q000097:blood / Q000453:epidemiology / Q000276:immunology*; D006801:Humans; D008297:Male; D019083:Mediterranean Region / Q000453:epidemiology; D008875:Middle Aged; D009504:Neutrophils / Q000276:immunology*
D019268:Antibodies, Antineutrophil Cytoplasmic; D001324:Autoantigens