[Heterogeneity of antimicrosomal autoantibodies in chronic hepatitis C virus infection and delta hepatitis].

Abstract

Microsomal antigen autoantibodies are typical of type 2 autoimmune hepatitis, and a strong association with chronic hepatitis C virus (HCV) infection has been reported in certain geographical areas. These autoantibodies have been denominated LKM-1 to differentiate them from those associated with thienylic acid-induced hepatitis (LKM-2) and from those seen in patients with chronic delta hepatitis (LKM-3). To investigate the antigenic specificity of autoantibodies associated with chronic hepatitis C and delta, we analyzed 52 LKM-1 positive serum samples from patients with chronic hepatitis C and 17 LKM-3 positive serum samples from patients with chronic delta hepatitis by indirect immunofluorescence and Western blotting (immunoblotting). Reactivity of subjects with chronic hepatitis C was heterogeneous: only 5 out of 52 LKM-1 positive patients, tested by Western blot, recognized a single protein of 50 kD, previously identified by Manns et al. with an immunogenic epitope of cytochrome P450IID6. Thirteen of the 52 patients also reacted with a 70 kD microsomal protein, and 12 out of 52 reacted only with a 59 kD protein. Twenty-two sera, notwithstanding the high titer in immunofluorescence, did not evidence any reactivity when tested by Western blot. The same sera tested positive in LKM-1 ELISA when solubilized human microsomal proteins were used. Fourteen out of 17 LKM-3 positive sera from patients with chronic hepatitis delta recognized a 55 kD microsomal protein in Western blot; three sera, HCV and HIV positive, did not react with any protein by Western blot. None of these sera was positive in ELISA LKM-1.(ABSTRACT TRUNCATED AT 250 WORDS)

• Authors: M Durazzo, C Costa, E Schmidt, S Loges, L Scaglione, A G Touscoz, A Smedile, M P Manns, M Rizzetto, G Pagano
• Journal: Annali italiani di medicina interna : organo ufficiale della Societa italiana di medicina interna (Ann Ital Med Int) 1995 Apr-Jun Vol. 10 Issue 2 Pg. 93-7 ISSN: 0393-9340 [Print] Italy
• Vernacular Title: Eterogeneità degli autoanticorpi antimicrosoma nell'infezione cronica da virus dell'epatite C e dell'epatite delta.
• PMID: 7542466 (Publication Type: Comparative Study, English Abstract, Journal Article)

Chemical References

• Autoantibodies
• Epitopes

Topics

• Antibody Specificity
• Autoantibodies (analysis)
• Blotting, Western
• Chronic Disease
• Enzyme-Linked Immunosorbent Assay
• Epitopes
• Female
• Fluorescent Antibody Technique
• Hepatitis C (immunology)
• Hepatitis D (immunology)
• Humans
• Kidney (immunology)
• Male
• Microsomes (immunology)
• Microsomes, Liver (immunology)