[Usefulness of autoantibodies in the study of autoimmune liver diseases and prevalence of autoimmune extrahepatic manifestations].
BACKGROUND
Autoantibodies are prominent findings in the diagnosis of autoimmune liver diseases. However, their usefulness is limited due to the high reported prevalence in others nonautoimmune disorders. The purpose of this report was to assess the significance of these markers in patients with autoimmune liver diseases and to determine the prevalence of extrahepatic autoimmune phenomena.


METHODS
We evaluated the samples from all the patients with altered biochemical liver parameters (ALT, AST, alkaline phosphatase or bilirubin) and a complete profile of autoimmunity [Anti-nuclear (ANA), anti-mitocondrial (AMA), anti-smooth muscle (SMA) and anti-liver/kidney microsomes (LKM1) antibodies] received in the Immunology Laboratory from 1993 to 1996. The records of the patients with at least one positive serologic marker were retrospectively reviewed. Autoimmune liver diseases (Autoimmune hepatitis (AIH), Primary biliary cirrhosis (PBC) and Overlap syndromes) were diagnosed according to composite clinical, analytical, histological or response-to-treatment parameters.


RESULTS
Samples from 548 patients were analyzed. Of these 85 (15.5%) were positive for at least one antibody. Disorders and autoantibodies were: Autoimmune liver diseases: 18 (4 AIH, 11 PBC, 3 Overlap syndromes); alcohol-induced liver disease: 14 (5 ANA, 9 SMA), Chronic HCV infection: 28 (9 ANA, 17 SMA, 2 ANA + SMA), Chronic HCV + AIH: 2 (1 ANA, 1 ANA + SMA); other liver diseases: 7 (4 ANA, 1 AMA, 2 SMA); other diseases with liver involvement: 10 (8 ANA, 2 SMA); no liver disease (normal): 6 (3 ANA, 1 AMA, 2 SMA). In 75% (64/85) of the positivities processes regarded as immunological liver disease were not found. We identified in 12 out of 20 patients with autoimmune liver diseases others autoimmune extrahepatic processes; in 4 before a diagnosis of liver disease was made.


CONCLUSIONS
Autoimmune serologic markers are useful in the study of liver diseases. However, due to inespecifity each individual patient deserves a careful evaluation. Autoimmune extrahepatic manifestations are often found and in some cases allow to recognize the hepatic involvement.
Montes Santiago
J
J
Servicio de Medicina Interna, Hospital Meixoeiro, Vigo, Pontevedra. jmontes@unimeixo.cesga.es
Gambón Deza
F
F
García García
M J
MJ
González Vázquez
L
L
Hermo Brión
J A
JA
Pérez Alvarez
R
R
D001323:Autoantibodies / Q000097:blood*; D001327:Autoimmune Diseases / Q000097:blood / Q000175:diagnosis* / Q000453:epidemiology*; D015415:Biomarkers / Q000097:blood; D006801:Humans; D008107:Liver Diseases / Q000097:blood / Q000175:diagnosis* / Q000276:immunology*; D015995:Prevalence; D012189:Retrospective Studies
D001323:Autoantibodies; D015415:Biomarkers