Antiviral drug-associated potential vaccine-escape hepatitis B virus mutants in Turkish patients with chronic hepatitis B.

BACKGROUND: The hepatitis B virus (HBV) polymerase (pol) gene completely overlaps with the envelope (S) gene. Mutations in the pol gene of HBV, either from selection of primary or secondary resistance mutations, typically result in changes in the overlapping hepatitis B surface antigen (HBsAg). Recent studies have conferred a new acronym to these HBV pol/S gene overlap mutants: ADAPVEMs, for antiviral drug-associated potential vaccine-escape mutants. The present study aimed to assess the prevalence and pattern of ADAPVEMs in Turkish patients with chronic hepatitis B (CHB). METHODS: The investigation was conducted between March 2007 and July 2010 and involved a total of 442 patients. These patients were in the following phases of HBV infection: immune tolerant (n=50), immune reactive (n=37), inactive carrier (n=90), HBeAg-negative CHB (n=217), and HBsAg-negative (n=12), or were hemodialysis patients (n=36). One hundred eighty-six patients were receiving nucleos(t)ide analogue (NUC) therapy and 256 patients had treatment-naïve CHB. RESULTS: Seven types of ADAPVEM were detected in the total CHB patients: rtM204V/sI195M, rtM204I/sW196S, rtM204I/sW196L, rtV173L/sE164D, rtA181T/sW172*, rtA181T/sW172L, and rtA181V/sL173F. The ADAPVEMs were associated with lamivudine, telbivudine, and adefovir. The prevalence of ADAPVEMs in all CHB patients was found to be 10% (46/442). The difference in the prevalence of ADAPVEMs across the different CHB clinical phases was not significant (Pearson Chi-square, p=0.112). The prevalence of ADAPVEMs was 24% (44/186) in those undergoing NUC therapy and 0.7% (2/256) in the treatment-naïve group; this difference was significant (Pearson Chi-square, p=0.00). CONCLUSIONS: We determined the prevalence and pattern of ADAPVEMs in Turkish patients in the different phases of CHB. Preferred drugs in Turkey, such as lamivudine, have the potential to cause the emergence of ADAPVEMs, with the possibility that these will spread to both individuals immunized with the hepatitis B vaccine and nonimmunized individuals. ADAPVEMs should be monitored in infected and treated patients and their public health risks assessed.

Monitoring of hepatitis B virus surface antigen escape mutations and concomitantly nucleos(t)ide analog resistance mutations in Turkish patients with chronic hepatitis B.

BACKGROUND: The hepatitis B virus (HBV) polymerase gene completely overlaps with the envelope gene. In the present study we aimed to monitor the prevalence and pattern of the typical mutations for hepatitis B surface antigen (HBsAg) escape, and concomitantly nucleos(t)ide analog (NUC) resistance mutations, in Turkish patients undergoing different antiviral therapies and in treatment-naïve patients with chronic hepatitis B (CHB). METHODS: The investigation was undertaken between March 2007 and August 2009 and involved a total of 142 patients under NUC therapy (88 males; mean age 42 years (range 13-68); hepatitis B e antigen (HBeAg) negativity in 94 patients; HBV DNA median log 4.3 log(10) IU/ml (range 2.0->6.0); alanine aminotransferase (ALT) median level 76.1 IU/ml (range 12-1082)) and 185 treatment-naïve CHB patients (120 males; mean age 39 years (range 1-76 years); HBeAg negativity in 132 patients; HBV DNA median log 3.5 log(10) IU/ml (range 2.0-6.0); ALT median level 60.7 IU/l (range 8-874)). RESULTS: The overall prevalence of typical HBsAg escape mutations found in the CHB patients was 8.3% (27/327). In the NUC therapy group the prevalence was 8.5% (12/142), with the following patterns: sY100C+sI110V, sL109I, sP120T, sP127T, sG130R+sG145X, sS132A+sY134N, sY134N+sG145R, sC137G, sD144E, sG145R. In the treatment-naïve group the prevalence was 8.1% (15/185), with the following patterns: sL109I, sI110V, sS117INST, sP120T, sP127T, sM133I, sC137L+sG145R, sS143L. However, NUC resistance mutations were found in 7.7% (11/142) of the patients on NUC therapy and 3.8% (7/185) of the treatment-naïve group patients. Interestingly, the treatment-naïve patients had preexisting drug resistance mutations related to lamivudine (rtL180M+rtM204I), adefovir (rtA181V, rtQ215S, rtI233V), entecavir (intermediate susceptibility with rtL180M+rtM204IHBV variant), telbivudine (rtL180M+rtM204I), and tenofovir (rtA194T). CONCLUSIONS: The findings of this study show preexisting typical HBsAg escape and NUC resistance mutations are possible. The genetic arrangement of the HBV genome with polymerase and surface genes overlapping has substantial public health and diagnostic implications and relevance.

Naturally occurring amino-acid substitutions to nucleos(t)ide analogues in treatment naive Turkish patients with chronic hepatitis B.

Naturally occurring amino-acid substitutions in the hepatitis B virus (HBV) polymerase gene may be responsible for resistance to nucleoside/nucleotide (NUCs) analogues. To date, only pre-existing lamivudine resistance has been extensively studied. The aim of the present study was to determine the naturally occurring or pre-existing amino-acid substitutions related to NUCs in treatment naive Turkish patients with chronic hepatitis B (CHB). The investigation involved a total of 88 patients (65 males and 23 females; mean age, 34 years; range, 15-61 years) who were diagnosed with CHB between April 2008 and January 2009. According to HBeAg status, 66 patients were HBeAg-negative and 22 patients were HBeAg positive. Naturally occurring substitutions in the HBV polymerase region were detected by DNA sequencing in 17 (19%) and 30 (34%) patients, based on manual and geno2pheno tool database interpretation, respectively. Each amino-acid substitution appeared alone and included rtA194T, rtV214A, rtQ215S, rtI233V and rtN236T. The median values for viral load, ALT and AST were 3.3 log(10) (2.0-6.0) IU/mL, 36 (12-515) U/L and 27 (13-284) U/L, respectively, but these did not correlate with the observed amino-acid substitutions in the polymerase region. By direct sequencing, genotype D of HBV was found to still be dominant among Turkish patients. In conclusion, every patient who is diagnosed with CHB should be monitored before the start of treatment for more effective management of patient treatment options.

The response to pegylated interferon alpha 2a in haemodialysis patients with hepatitis C virus infection.

The aim of this retrospective study was to focus the efficacy of pegylated interferon (PEG-IFN) alpha 2a in chronic hemodialysis patients with hepatitis C and to compare the therapy responses with other chronic hepatitis C patients. Of the anti-HCV positive patients who were admitted to the Infectious Diseases and Clinical Microbiology policlinic from January 2004 to December 2006, 99 were candidates for interferon therapy. Of those, 12 patients were on HD. We began 47 patients on PEG-IFN alpha 2a (180 lg/week) subcutaneously plus ribavirin (1,000-1,200 mg/day) (Group 1), and 12 patients on HD, PEG-IFN alpha 2a, without ribavirin at a dose of 135 lg weekly for 48 weeks (Group 2). In this study of PEG IFN alpha 2a with or without ribavirin, the predictability of a sustained viral response (SVR) was based on the early virologic response (EVR) defined at week 12 as an at least 2-log decline from baseline of the HCV RNA level. About 77% (39/47) of patients achieved an EVR in Group 1 and 58% (7/12) in Group 2 (p = 0.004). A total of 34 (72.34%) patients in Group 1 and 6 patients (50%) in Group 2 had negative HCV RNA at the end of the treatment (p = 0.213). We evaluated SVR after 6 months finishing the therapy; 29 (61.7%) patients in Group 1 and 6 patients (50%) in Group 2 had negative HCV RNA (p = 0.109). PEG-IFN alpha 2a (135 lg weekly) for 48 weeks is efficacious and well tolerated in HD patients with HCV, as well as other chronic HCV patients. However, due to more side effects of IFN specially on platelet counts as compared non-renal HCV patients a closer follow-up, in HD patients is suggested.

A probable case of herpes simplex encephalitis despite negative PCR findings.

A 54-year-old woman was admitted to the hospital suffering from fever and personality changes. Laboratory examination of her cerebrospinal fluid (CSF) showed 270 mononuclear cells, 30 polynuclear cells and a clinically low number of erythrocytes/mm3. Empirical clinical findings from this case suggested treatment with acyclovir. Magnetic resonance imaging (MRI) showed bilateral temporal hyperintense signals in T2-weighted images. PCR with specific primer for herpes simplex virus type 1 (HSV-1) and HSV-2 were negative. There was no elevation of oligoclonal antibodies specific to HSV in CSF after 2 weeks. Although we did not prove the presence of the agent microbiologically at the clinical onset of the disease, the MRI and electroencephalogram (EEG) findings, erythrocytes in CSF and the dramatic response to acyclovir therapy are suggestive of a diagnosis of herpes simplex encephalitis (HSE).