Louis Jansen1, Annikki de Niet1, Femke Stelma1, Erik P A van Iperen2, Karel A van Dort3, Marjan J Tempelmans Plat-Sinnige1, R Bart Takkenberg4, Daniel J Chin5, A H Koos Zwinderman6, Uri Lopatin7, Neeltje A Kootstra3, Hendrik W Reesink8. 1. Department of Gastroenterology and Hepatology, Academic Medical Center (AMC), University of Amsterdam (UvA), Amsterdam, The Netherlands; Department of Experimental Immunology, AMC, UvA, The Netherlands. 2. Department of Clinical Epidemiology, Biostatistics, and Bioinformatics, AMC, UvA, The Netherlands; Durrer Center for Cardiogenetic Research, Amsterdam, The Netherlands. 3. Department of Experimental Immunology, AMC, UvA, The Netherlands. 4. Department of Gastroenterology and Hepatology, Academic Medical Center (AMC), University of Amsterdam (UvA), Amsterdam, The Netherlands. 5. Hoffman La Roche, Nutley, USA. 6. Department of Clinical Epidemiology, Biostatistics, and Bioinformatics, AMC, UvA, The Netherlands. 7. Assembly Pharmaceuticals, Bloomington, IN, USA. 8. Department of Gastroenterology and Hepatology, Academic Medical Center (AMC), University of Amsterdam (UvA), Amsterdam, The Netherlands. Electronic address: h.w.reesink@amc.nl.
Abstract
BACKGROUND & AIMS: Achievement of HBsAg loss remains the hallmark of chronic hepatitis B treatment. In order to identify host factors contributing to treatment-induced HBsAg loss, we performed a genome-wide screen of single nucleotide polymorphisms (SNPs) and studied its immunological consequence. METHODS: Chronic hepatitis B patients (40 HBeAg-positive and 44 HBeAg-negative) treated with peginterferon alfa-2a and adefovir were genotyped for 999,091 SNPs, which were associated with HBsAg loss at week 96 (n = 9). Plasma carnitine levels were measured by tandem-mass spectrometry, and the effect of carnitine on the proliferative capacity of hepatitis B virus (HBV)-specific and non-specific CD8 T cells was studied in vitro. RESULTS: One polymorphism, rs12356193 located in the SLC16A9 gene, was genome-wide significantly associated with HBsAg loss at week 96 (p = 1.84 × 10(-8)). The previously reported association of rs12356193 with lower carnitine levels was confirmed in our cohort, and baseline carnitine levels were lower in patients with HBsAg loss compared to patients with HBsAg persistence (p = 0.02). Furthermore, we demonstrated that carnitine suppressed HBV-specific CD8 T cell proliferation. CONCLUSIONS: In chronic hepatitis B patients treated with peginterferon and adefovir, we identified strong associations of SLC16A9 gene variation and carnitine levels with HBsAg loss. Our results further suggest that a lower baseline plasma carnitine level increases the proliferative capacity of CD8 T cells, making patients more susceptible to the immunological effect of this treatment. These novel findings may provide new insight into factors involved in treatment-induced HBsAg loss, and play a role in the prediction of treatment outcome.
BACKGROUND & AIMS: Achievement of HBsAg loss remains the hallmark of chronic hepatitis B treatment. In order to identify host factors contributing to treatment-induced HBsAg loss, we performed a genome-wide screen of single nucleotide polymorphisms (SNPs) and studied its immunological consequence. METHODS: Chronic hepatitis Bpatients (40 HBeAg-positive and 44 HBeAg-negative) treated with peginterferon alfa-2a and adefovir were genotyped for 999,091 SNPs, which were associated with HBsAg loss at week 96 (n = 9). Plasma carnitine levels were measured by tandem-mass spectrometry, and the effect of carnitine on the proliferative capacity of hepatitis B virus (HBV)-specific and non-specific CD8 T cells was studied in vitro. RESULTS: One polymorphism, rs12356193 located in the SLC16A9 gene, was genome-wide significantly associated with HBsAg loss at week 96 (p = 1.84 × 10(-8)). The previously reported association of rs12356193 with lower carnitine levels was confirmed in our cohort, and baseline carnitine levels were lower in patients with HBsAg loss compared to patients with HBsAg persistence (p = 0.02). Furthermore, we demonstrated that carnitine suppressed HBV-specific CD8 T cell proliferation. CONCLUSIONS: In chronic hepatitis Bpatients treated with peginterferon and adefovir, we identified strong associations of SLC16A9 gene variation and carnitine levels with HBsAg loss. Our results further suggest that a lower baseline plasma carnitine level increases the proliferative capacity of CD8 T cells, making patients more susceptible to the immunological effect of this treatment. These novel findings may provide new insight into factors involved in treatment-induced HBsAg loss, and play a role in the prediction of treatment outcome.
Authors: Álvaro Anzai; Rodrigo R Marcondes; Thiago H Gonçalves; Kátia C Carvalho; Manuel J Simões; Natália Garcia; José M Soares; Vasantha Padmanabhan; Edmund C Baracat; Ismael D C G da Silva; Gustavo A R Maciel Journal: Sci Rep Date: 2017-10-13 Impact factor: 4.379