▁b ile ▁du ct , ▁which ▁is ▁believed ▁to ▁be ▁auto imm une ▁in ▁origin . ▁ ▁Bud d – Ch i ari ▁synd rome ▁is ▁the ▁clin ical ▁picture ▁caused ▁by ▁occ l usion ▁of ▁the ▁he p atic ▁ve in . ▁ ▁Mechan ism ▁Liver ▁disease ▁can ▁occur ▁through ▁several ▁mechan isms : ▁ ▁DNA ▁damage ▁One ▁general ▁mechanism , ▁increased ▁DNA ▁damage , ▁is ▁shared ▁by ▁some ▁of ▁the ▁major ▁causes ▁of ▁li ver ▁disease . ▁ ▁These ▁major ▁causes ▁include ▁in fection ▁by ▁he pat itis ▁B ▁virus ▁or ▁he pat itis ▁C ▁virus , ▁alco hol ▁ab use , ▁and ▁ob es ity . ▁ ▁Vir al ▁in fection ▁by ▁he pat itis ▁B ▁virus ▁( H B V ) ▁or ▁he pat itis ▁C ▁virus ▁( H CV ) ▁causes ▁an ▁increase ▁of ▁re active ▁o xygen ▁species ▁( RO S ). ▁ ▁The ▁increase ▁in ▁int rac ell ular ▁R OS ▁is ▁about ▁ 1 0 , 0 0 0 - fold ▁upon ▁chron ic ▁H B V ▁in fection ▁and ▁ 1 0 0 , 0 0 0 - fold ▁after ▁H CV ▁in fection . ▁ ▁This ▁increase ▁in ▁R OS ▁causes ▁infl amm ation ▁and ▁further ▁increase ▁in ▁R OS . ▁ ▁R OS ▁cause ▁more ▁than ▁ 2 0 ▁types ▁of ▁DNA ▁damage . ▁ ▁Ox id ative ▁DNA ▁damage ▁is ▁mut agen ic ▁and ▁also ▁causes ▁ep igen etic ▁alter ations ▁at ▁the ▁sites ▁of ▁DNA ▁repair . ▁ ▁Ep igen