Volume 125, Issue 6, Pages 1705-1713 (December 2003) Autoreactivity to lipoate and a conjugated form of lipoate in primary biliary cirrhosis  Sylvaine F.A Bruggraber, Patrick S.C Leung, Katsushi Amano, Chao Quan, Mark J Kurth, Michael H Nantz, Gordon D Benson, Judy Van de Water, Velimer Luketic, Thomas E Roche, Aftab A Ansari, Ross L Coppel, M.Eric Gershwin  Gastroenterology  Volume 125, Issue 6, Pages 1705-1713 (December 2003) DOI: 10.1053/j.gastro.2003.09.034

Figure 1 Reactivity of total sera from healthy volunteers (n = 42), AMA-positive patients with PBC (n = 97), AMA-negative patients with PBC (n = 8), patients with primary sclerosing cholangitis (PSC) (n = 69), and patients with rheumatoid arthritis (RA) (n = 28) against HSA-LA, RSA, or KLH. Values are presented as mean ± SEM of the average OD unit of 3 samples per serum measured by direct ELISA after correction for the background activity on the protein alone. Triplicate dilutions of sera were prepared in 1:1000 in 0.05% tween 20 in PBS buffer containing 3% milk. Reactivity of total sera on the protein alone, all groups combined, was 0.042 ± 0.008, 0.036 ± 0.003, and 0.095 ± 0.004 for RSA, HSA, and KLH, respectively. Gastroenterology 2003 125, 1705-1713DOI: (10.1053/j.gastro.2003.09.034)

Figure 2 Correlation between reactivity of total sera from patients with PBC (n = 105) to HSA-LA with their reactivity to recombinant PDC-E2, measured by ELISA (r = 0.34, solid line). Values are the average OD of 3 samples per serum. OD for HSA-LA corrected for background activity on HSA alone. Sera were considered positive if OD >0.085 for HSA-LA (dashed line) and OD >0.239 for PDC-E2 (mean ± 2 SD of the group of healthy volunteers). Gastroenterology 2003 125, 1705-1713DOI: (10.1053/j.gastro.2003.09.034)

Figure 3 Titration of PBC sera against HSA-LA, PDC-E2, and lipoylated PDC-E2. Values represent average OD ± SEM of 5 PBC sera. Paired t test was determined for HSA-LA and PDC-E2 as well as HSA-LA and lipoylated PDC-E2. ∗P < 0.01, ∗∗P < 0.001. Gastroenterology 2003 125, 1705-1713DOI: (10.1053/j.gastro.2003.09.034)

Figure 4 Reduction of serum reactivity against HSA-LA, nonlipoylated PDC-E2, and lipoylated PDC-E2 after progressive adsorption with (A) HSA, (B) HSA-LA, (C) nonlipoylated PDC-E2, and (D) lipoylated PDC-E2 at various points of adsorption. Values are percentage ± SEM (n = 5) of remaining reactivity before adsorption. ∗P < 0.01, ∗∗P < 0.001. Gastroenterology 2003 125, 1705-1713DOI: (10.1053/j.gastro.2003.09.034)

Figure 5 Reactivity of PBC sera against (A) lipoylated KLH, (B) lipoylated PDC-E2, and (C) PDC-E2 after adsorption with lipoylated PEG, PEG compound #3, and PEG. PBC sera did not react with KLH. Values presented as percentage ± SEM (n = 5) of Ig reactivity before adsorption. ∗P < 0.05, ∗∗P < 0.01. Gastroenterology 2003 125, 1705-1713DOI: (10.1053/j.gastro.2003.09.034)