Double reactivity against actin and alpha-actinin defines a severe form of autoimmune hepatitis type 1.
Anti-filamentous actin antibodies characterize autoimmune hepatitis type 1 (AIH-1). Recently, the binding domain of alpha-actinin on actin was shown to be a predominant epitope. To test this reactivity, an anti-alpha-actinin enzyme-linked immunosorbent assay was developed, and positivity confirmed by Western blot. Anti-alpha-actinin antibody was found in 21/50 (42%) of AIH-1 patients, compared with 52/401 (12.9%) of liver disease control patients, and with 6/200 (6%) of blood donors. Anti-filamentous and anti-alpha-actinin activities were found specifically together in 66% of anti-filamentous-positive AIH-1 patients. This combination of specificities reflected clinical and histological disease activity, short duration and absence of treatment. Finally, using an actin-alpha-actinin complex assay, the binding of anti-filamentous actin to alpha-actinin-binding domain on actin was demonstrated, as well as that of anti-alpha-actinin on the actin-binding domain of alpha-actinin. Thus, the frequent combination of anti-filamentous and anti-alpha-actinin antibodies seems to be the hallmark of activity in AIH-1.
Guéguen
Paul
P
Laboratory of Immunology, Brest University Medical School Hospital, Brest, France.
Dalekos
Georgios
G
Nousbaum
Jean-Baptiste
JB
Zachou
Kalliopi
K
Putterman
Chaim
C
Youinou
Pierre
P
Renaudineau
Yves
Y
D000185:Actinin / Q000276:immunology*; D000199:Actins / Q000276:immunology*; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001323:Autoantibodies / Q000097:blood*; D002648:Child; D003429:Cross Reactions; D004277:DNA, Single-Stranded / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D019693:Hepatitis, Autoimmune / Q000276:immunology*; D006801:Humans; D008297:Male; D008875:Middle Aged
D000199:Actins; D001323:Autoantibodies; D004277:DNA, Single-Stranded; D000185:Actinin