Selection of mutations in the hepatitis B virus polymerase during therapy of transplant recipients with lamivudine

Abstract

effects, these drugs may have a valuable role in reducing We describe mutations in the hepatitis B virus (HBV) virus load prior to OLT and in helping to prevent infection polymerase gene in viruses which reactivated in two paof the graft in the immediate postoperative period. Clinical tients during therapy with -2-deoxy-3-thiacytidine, or trials are in progress. lamivudine (3TC), and following orthotopic liver trans-We report here the analysis of polymerase sequences of plantation for chronic hepatitis B. Virus resistance to HBV from two patients treated with 3TC and in whom repli-3TC is associated with mutations which lead to amino cation of seemingly resistant virus followed a period of inhibiacid substitutions in the highly conserved tyr-met-asption. Despite the discovery that the HBV genome replicates via The Pol ORF region was amplified in three segments using nested reverse transcription of an RNA intermediate, nucleoside an-PCR and was sequenced using the primers listed in Table 1. Briefly, alogs have proven rather less effective in inhibiting virus PCR 1 used primers BPOL BO2 plus BPOL EO1 followed by BPOL replication than is the case for human immunodeficiency vi-BI2 plus PSI SEQ2; the product was cloned and sequenced using the rus (HIV). Recently, however, -2-deoxy-3-thiacytidine, or following primers: -40 and reverse primers (in vector, pCRII), and BPOL BI2, PS1 SEQ2, POL SEQ4, DSI, POL SEQ5. PCR 2 used lamivudine 2 (3TC), and famciclovir 3 have proven useful in primers LS BI1 plus POL SEQ3 followed by DS2 plus POL SEQ2;reducing virus load, although virus replication may return the product was cloned and sequenced using the following primers:to former levels when treatment is withdrawn. While it re--40 and reverse primers, and POL SEQ2, DS, S SEQ1, LSIE1, and mains to be determined whether prolonged treatment of HBV SE. PCR 3 used MD14 plus BPOL EO1 followed by ME15 plus chronic carriers will be tolerated without cumulative adverse BPOL EI1; the product was cloned and sequenced using the following primers: -40 and reverse primers (in vector), and POL SEQ3, BPOL EI1, and POL SEQ6. Sequence Analysis. A consensus of the HBV polymerase sequencesAbbreviations: HBV, hepatitis B virus; OLT, orthotopic liver transplantation; HIV, huin the protein databases, reproduced in part in Fig. 2, was generated man immunodeficiency virus; 3TC, (-)2-deoxy-3-thiacytidine (lamivudine); HBsAg, hepatiusing the PILEUP and PRETTY software programs (GCG Software, tis B surface antigen; HBeAg, hepatitis B e antigen; anti-HBe, antibody to HBeAg; Pol Madison, WI).

Structural Insights into HIV Reverse Transcriptase Mutations Q151M and Q151M Complex That Confer Multinucleoside Drug Resistance

“…The nucleoside analog anti-HIV-1 drugs, such as the ␤-L-oxathiolane ringcontaining lamivudine (3TC) and acyclic tenofovir (or adefovir), are effective inhibitors of HBV polymerase and are used clinically to treat HBV-infected individuals (37,38). Analogous nucleoside drug resistance mutations emerge in HBV polymerase and in HIV-1 RT under specific drug pressure; e.g., HIV-1 RT mutation M184V and HBV polymerase mutation M204V emerge in the YMDD loop in response to 3TC treatments (39). Interestingly, the positional analog for HIV-1 RT Q151 is a methionine (M171) in wild-type HBV (wtHBV) polymerase; residues R72, Y116, and M151, which are observed to be responsible for altering and stabilizing the conformational state of the dNTPbinding pocket of Q151Mc HIV-1 RT, are also conserved as amino acid residues R41, Y89, and M171, respectively, in wtHBV polymerase.…”

Acute liver graft failure due to emergence of lamivudine resistant hepatitis B virus: rapid resolution during treatment with adefovir

“…These changes comprise a methionine for valine (M552V) or methionine for isoleucine (M552I) substitution at amino acid residue 552, with other changes including methionine for leucine at position 528 (L528M) of the polymerase. Indeed, these lamivudine resistant species were first described in the context of failed prophylaxis following liver transplantation 6. As observed for HBIg prophylaxis, failure of lamivudine prophylaxis may be predicted for patients with high pretreatment serum HBV titre 7…”

Pretreatment and on-treatment predictors of viral breakthrough in lamivudine therapy for chronic hepatitis B

“…A high incidence of viral breakthrough (VBT) that results from viral resistance is a major disadvantage of prolonged LAM therapy for CHB [7]. Selective amplification of resistant mutants is the main concern of long-term LAM therapy [8,9]. During continuation of LAM treatment, exacerbation of CHB was reported in 40.6% of patients carrying resistant mutants [10].…”