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All about Autoimmunity
ESL Biosciences in partnership with Euroimmun AG, offer
the most comprehensive range of diagnostic products and
services for the determination of Autoantibodies
INFORMATION
BULLETIN
ISSUE 11
NOVEMBER 2012
IIFT: BIOCHIP Mosaic Rat Stomach (ASMA)/VSM47
Cells (F-Actin)
Indication: Test system for the in vitro determination of antibodies against smooth muscles (ASMA,
anti-smooth muscle antibodies) filamentous actin (F-actin) in human serum or plasma for the diagnosis
of autoimmune hepatitis.
ASMA (rat stomach)
F-actin (VSM47 cells)
Clinical significance: The
determination of ASMA is of
particular importance in the
diagnosis of autoimmune
hepatitis (AIH). AIH is an
immune-mediated chronic
inflammation of the liver. As
most autoimmune diseases, AIH
occurs predominantly in women
(>80%). In a Norwegian study
the incidence was determined as
0.1 to 1.9 cases per 100,000
inhabitants per year. In around
40% of AIH patients the disease
starts with acute symptoms. The
main clinical symptoms are
tiredness and weakness. These
can be followed by joint pain and
arthritis, thyroiditis, diabetes
mellitus, colitis and
conjunctivitis. The disease often
progresses to liver cirrhosis.
Hepatocellular carcinoma can also
develop. The 10 year survival rate
in severe cases is about 10%.
Even with appropriate treatment
there is a risk of early liver failure,
usually within 6 months. For this
reason, liver transplantation must
be considered in time. The 5-year
survival rate after transplantation
is around 90%. High ASMA levels
are associated with AIH in 70% of
cases. They often occur together
with anti-nuclear antibodies (ANA)
and antibodies against doublestranded
DNA. According to the
International Autoimmune
Hepatitis Group (IAHG) the
presence of ASMA is one
diagnostic criterion. The IgG and
IgM titers can correlate with
disease activity. ASMA are
directed against different antigens
of smooth muscles. The most
important target antigen is
filamentous actin in cytoskeletal
microfilaments and muscle fibres.
With frozen sections of rat or
mouse stomach ASMA show a
distinct cytoplasmic fluorescence
of the tunica muscularis as well
as the lamina muscularis
mucosae and the interglandular
contractile fibrils of the tunica
mucosa.
Specific antibodies against
F-actin can be detected using
the cell line VSM47 (vascular
smooth muscle). This
substrate shows a typical
crystal-like fluorescence
pattern.

ISSUE 11 NOVEMBER 2012
Clinical data: 100 sera from
patients with clinically
characterised type I autoimmune
hepatitis (type I AIH) and 217
control sera (from patients with
type II AIH (n=20), primary
biliary cirrhosis (PBC) (n=65),
primary sclerosing cholangitis
(PSC) (n=32), non-alcohol
induced liver diseases (n=60)
and from healthy blood donors
(n=40) were investigated for
antibodies against F-actin using the
EUROIMMUN Anti F-Actin IIFT
(VSM47 cells). The sensitivity of the
test system in the type I AIH cohort
was 56%, the specificity in the
control cohort was 99%.
Source: Report on the 6th Congress on Autoimmunity
(A98), Porto, Portugal, September
2008 ; Quarneti, C. et al.: high specificity for
type 1 autoimmune hepatitis of antimicrofilament
antibodies detected on a new
cell line.
Application of the BIOCHIP Mosaic Rat Stomach (ASMA)/VSM47 Cells (F-Actin):
Antibodies against smooth muscle have a high significance in the diagnosis of AIH, but they can also occur
in other diseases (e.g. viral infections, chronic hepatitis or infectious mononucleosis). By combining the
two IIFT substrates stomach and VSM47 cells, actin and non-actin patterns can be differentiated in a single
incubation. Since antibodies against F-actin are specific for type I AIH, the substrate combination allows
classification of the disease. Antibodies against F-actin are directed against conformational epitopes. For
this reason they are poorly detected by ELISA or Westernblot, but can be determined particularly well
using IIFT.
Publication:
Diagnostic accuracy of four different immunological methods for the detection of anti-F-actin
autoantibodies in type 1 autoimmune hepatitis and other liver-related disorders
DANILO VILLALTA, et al. Autoimmunity, February 2008; 41(1): 105-110
Abstract:
“... Both IIF methods, the one on rat tissues and the other on VSM47 cell line, are highly specific for AIH-1.
In contrast, ELISA and especially ID show positive results in control population ... Therefore, having a high
positive predictive value, both IIF methods are reliable tools for the specific detection of AIH-associated
anti-F-actin autoantibodies ...”
TECHNCA DATA:
Antigen substrate: Frozen tissue sections of rat stomach and VSM47 cells (vascular smooth muscle)
Sample:
Test procedure:
Reagents:
Serum of plasma
30 min (sample) / 30 min (conjugate), room temperature
Ready for use, with the exception of the PBS Tween buffer (for dilution and washing
steps).
PRODUCT ORDER NO’s.
FA 1651-XXXX
FA 1710-XXXX
F-Actin VSM47
(Test systems available: 10 x 3 ; 10 x 5 & 10 x 10)
ASMA, F-actin, Rat stomach
(Test systems available: 10 x 3 ; 10 x 5 & 10 x 10 ; 20 x 5 & 20 x 10)
For a copy of the reference above and/or test instructions for the EUROIMMUN slides
please contact your ESL Sales & Applications Specialist