BACKGROUND:?The?deifnition?of?partial?virological?response?(PVR)?was?proposed?because?of?its?clinical?relevance.?PVR?relates?to?subsequent?therapeutic?failure?which?results?in?the?modiifcation?of?the?regimen.?Whether?this?rationale?can?be?applied?to?all?nucleotide?analogues?(NA)?is?not?clear.?This?study?was?undertaken?to?analyze?PVR?inlfuence?on?therapeutic?outcomes?during?lamivudine,?entecavir?or?tenofovir?mono- therapy?in?NA-naive?patients?with?chronic?hepatitis?B?in?routine?clinical?practice.
METHODS:?We?retrospectively?analyzed?150?NA-naive?patients?with?chronic?hepatitis?B.?These?subjects?received?lamivudine,?entecavir?or?tenofovir?monotherapy?between?February?2001?and?July?2013.
RESULTS:?Sixty-nine?patients?were?treated?with?lamivudine,?35?with?entecavir,?and?46?with?tenofovir.?The?median?therapeutic?duration?was?19.5?(6-147)?months.?PVR?rates?at?24?weeks?were?similar?among?three?NAs?(lamivudine?33.3%,?entecavir?35.0%,?tenofovir?32.4%,?P=0.981).?For?all?three?NAs,?patients?with?a?higher?baseline?viral?load?or?HBeAg-positive?status?had?a?higher?serum?viral?positive?rate?tested?by?polymerase?chain?reaction?at? week? 24? and? 48.? Cumulative? probability? of? virological?breakthrough?(VBR)?for?patients?treated?with?lamivudine?was?67%?at?5?years,?and?PVR?at?24?weeks?was?the?independent?risk?factor?for?VBR?(HR:?3.09;?95%?CI:?1.09-8.74;?P=0.034);?also?lamivudine?treated?patients?older?than?50?years?seemed?to?have?a?tendency?for?VBR?(HR:?2.80;?95%?CI:?0.99-8.18;?P=0.052).?A? majority? of? entecavir? and? tenofovir? partial? responders?achieved?and?maintained?virological?response?with?prolonged?monotherapy,? except? one? entecavir? treated? patient? who?experienced?VBR?due?to?resistance?mutations.
CONCLUSIONS:?Management?strategy?for?lamivudine?treatment?should?include?adaptation?of?regimen?according?to?PVR?as?an?on-treatment?response?parameter?due?to?its?relation?with?unacceptably?high?VBR?probability.?Similar?conclusion?should?not?be?directly?related?to?entecavir?or?tenofovir?treatment.