Prevalence of hepatitis C virus mutants resistant to protease inhibitors among Polish HCV genotype 1-infected patients.

AIM: The aim of this study was to evaluate prevalence of hepatitis C virus (HCV) harbouring mutations associated with decreased susceptibility to protease inhibitors (Boceprevir/Telaprevir) among Polish untreated patients infected with HCV genotype 1. MATERIAL AND METHOD: Population sequencing was used, sequencing data were interpreted by web based geno2pheno algorithm. A total of 91 serum samples were obtained from patients infected with HCV genotype 1, admitting Outpatient Clinics of Hospital of Infectious Diseases, Warsaw. RESULTS: Sequencing analysis of the NS3 protease catalytic domain was successful in 85 out of 91 subjects. In seventy three (85.9%) out of 85 samples wild-type HCV was detected; in 12 (14.1%) samples mutations associated with clinically observed Boceprevir/Telaprevir-decreased susceptibility were detected. SUMMARY AND CONCLUSIONS: Obtained results document the presence of HCV strains harbouring protease inhibitors (PIs) resistance-associated mutations among Polish therapy-naïve patients. The determined prevalence of drug resistant HCV variants is 14.1%. Further and continuous surveillance is necessary to estimate how preexisting and emerging drug resistance mutations influence clinical outcome in triple-therapy experienced patients.

Effect of hepatitis C infection on HIV-induced apoptosis.

BACKGROUND: Hepatitis C virus (HCV) coinfection was reported to negatively affect HIV disease and HIV infection has a deleterious effect on HCV-related liver disease. However, despite common occurrence of HCV/HIV coinfection little is known about the mechanisms of interactions between the two viruses. METHODS: We studied CD4+ and CD8+ T cell and CD19+ B cell apoptosis in 104 HIV-positive patients (56 were also HCV-positive) and in 22 HCV/HIV-coinfected patients treated for chronic hepatitis C with pegylated interferon and ribavirin. We also analyzed HCV/HIV coinfection in a Daudi B-cell line expressing CD4 and susceptible to both HCV and HIV infection. Apoptosis was measured by AnnexinV staining. RESULTS: HCV/HIV coinfected patients had lower CD4+ and CD8+ T cell apoptosis and higher CD19+ B cell apoptosis than those with HIV monoinfection. Furthermore, anti-HCV treatment of HCV/HIV coinfected patients was followed by an increase of CD4+ and CD8+ T cell apoptosis and a decrease of CD19+ B cell apoptosis. In the Daudi CD4+ cell line, presence of HCV infection facilitated HIV replication, however, decreased the rate of HIV-related cell death. CONCLUSION: In HCV/HIV coinfected patients T-cells were found to be destroyed at a slower rate than in HIV monoinfected patients. These results suggest that HCV is a molecular-level determinant in HIV disease.

Characteristics of HIV-1 non-B subtype infections in Northwest Poland.

The number of non-B subtype HIV-1 infections in Europe has been increasing even though major regional differences have been observed. This trend was investigated in northwestern Poland using sequence and epidemiological data from a cohort of 102 HIV-1-infected patients from Szczecin, Poland. HIV-1 subtypes were defined by phylogenetic analysis of viral reverse transcriptase- and protease-partial coding regions, and results were compared with online subtyping by Standford and REGA tools. Subtype analysis using on-line subtyping methods produced varying results if compared to phylogenesis, with concordant variant assignment obtained for 98% (100/102) of sequences by Stanford and 85% (87/102) by REGA. In the population studied, non-B subtype infections comprised 21% of the infections and consisted of subtype D (57%, n = 12), CRF01_AE (19%, n = 4), A and C clades (9.5%, n = 2), and the CRF13_cpx recombinant isolate (4.8%, n = 1). Patients carrying non-B subtypes were predominantly heterosexuals with high percentage (57%) of women observed in the group. All HIV-1 non-B women were Caucasian with majority (83%) of infections acquired in Poland; however, among 12 travelers included in the study a higher proportion of non-B infections was noted (50%, P = 0.01). Moreover, lower baseline lymphocyte CD4 counts (P = 0.01), higher baseline HIV-1 viremia (P = 0.08), and a more advanced stage of the disease (P = 0.03) were observed among individuals infected with non-B subtypes. The data indicated that the proportion of HIV-1 non-B subtype infections was higher than previously reported in Poland consisting of a high subtype D prevalence. Furthermore, subtype D transmission occurred primarily between heterosexual Caucasian individuals from this region.

Evolving patterns of HIV-1 transmitted drug resistance in Poland in the years 2000-2008.

The aim of the study was to determine the rate of transmission of drug resistant human immunodeficiency virus-1 (HIV-1) variants among therapy-naïve HIV positive patients in Poland in the year 2008, to compare the data with the results from the years 2000 to 2007 and to monitor patterns of HIV-1 subtypes present in Polish population and their evolution. Complete protease and part of reverse transcriptase regions were sequenced from the sera of patients directed to the laboratory for drug resistance testing. The Stanford's HIVdb program was used for the interpretation of results and subtyping. The variants scoring at least "intermediate resistance" for at least one drug were considered as resistant. The results obtained were compared to those obtained in the years 2000-2007. A total of 95 patients were enrolled in the 2008 study. Homosexual transmission of infection was documented in more than 55% of all cases. The overall prevalence of transmitted drug resistance (TDR) was 5.3% (3.9% in 2007, 5.8% in 2006, and 14.1% in the years 2002-2005). The study from the years 2000 to 2001 revealed 28.7% prevalence. Preliminary analysis of the first half of 2009 shows the ratio of 7.8%. In four (4.2%) cases drug resistance was associated with protease inhibitors class, in one case (1.1%) with resistance to non-nucleoside reverse transcriptase inhibitors class. In four cases (4.2%) non-B subtype was identified (C, G, CRF01_AE, CRF02_AG). An increase of percentage of drug resistant mutants-from 3.9% (2007) to 5.3% (2008)-was recognized. In this study, TDR was limited to single classes of antiretroviral drugs. HIV-1 subtype B prevails in Poland.

[Transmission of HIV-1 drug resistance among newly diagnosed patients in Poland]. / Transmisja lekoopornych szczepów HIV-1 wsród osób nowo diagnozowanych w Polsce.

OBJECTIVE: HIV-1 drug resistance is becoming a growing concern. It is estimated that one out of ten newly diagnosed persons in Europe acquires HIV drug resistant strain. The aim of this study was to determine the transmission of drug resistance and identify the resistance patterns among naïve patients in Poland. METHODS: The patients were asked to complete a brief questionnaire concerning demographic and epidemiological data. Viral load and CD4/CD8 counts were detemined before drug resistance testing. The sequencing assay was performed according to manufacturer's protocol. MAIN OBSERVATIONS: In the analysed cohort 14.7% of patients acquired HIV-1 drug resistant strains; further 9.5% were infected with strains with "possibly lowered susceptibility". RESULTS: In all cases resistance to single class of antiretroviral drugs were identified. In the class of PIs resistance to NFV was the most common. The rates of drug resistance among NNRTIs were almost the same--about 5%. In the NRTI class the resistance to AZT and d4T was the most frequent. HIV-1 subtype B was identified in 88.8% of cases. CONCLUSIONS: The results of this study document high transmission rate of drug resistance in Poland and justify the necessity of common DR testing in our country.

The calculated genetic barrier for antiretroviral drug resistance substitutions is largely similar for different HIV-1 subtypes.

BACKGROUND: The genetic barrier, defined as the number of mutations required to overcome drug-selective pressure, is an important factor for the development of HIV drug resistance. Because of high variability between subtypes, particular HIV-1 subtypes could have different genetic barriers for drug resistance substitutions. This study compared the genetic barrier between subtypes using some 2000 HIV-1 sequences (>600 of non-B subtype) isolated from anti-retroviral-naive patients in Europe. METHODS: The genetic barrier was calculated as the sum of transitions (scored as 1) and/or transversions (2.5) required for evolution to any major drug resistance substitution. In addition, the number of minor protease substitutions was determined for every subtype. RESULTS: Few dissimilarities were found. An increased genetic barrier was calculated for I82A (subtypes C and G), V108I (subtype G), V118I (subtype G), Q151M (subtypes D and F), L210W (subtypes C, F, G, and CRF02_AG), and P225H (subtype A) (P < 0.001 compared with subtype B). A decreased genetic barrier was found for I82T (subtypes C and G) and V106M (subtype C) (P < 0.001 vs subtype B). Conversely, minor protease substitutions differed extensively between subtypes. CONCLUSIONS: Based on the calculated genetic barrier, the rate of drug resistance development may be similar for different HIV-1 subtypes. Because of differences in minor protease substitutions, protease inhibitor resistance could be enhanced in particular subtypes once the relevant major substitutions are selected.

Modern diagnostics of Chlamydia trachomatis infections.

Chlamydia trachomatis (C. trachomatis) is the most common agent of sexually transmitted infections. The clinical spectrum of the disease ranges from urethritis to infertility in women and to trachoma. Intracellular localisation of the pathogen creates a challenge for routine diagnostics. In this review possible diagnostic tests have been presented, varying from classic cell culture analysis and serodiagnostics (Enzyme-linked Immunoassays, Indirect Immunofluorescence) to the most sophisticated nucleic acid analyses (hybridisation, Polymerase Chain Reaction, Transcription Mediated Amplification, Ligase Chain Reaction), Advantages and disadvantages of the leading tests are discussed. Possible reasons of false positive as well as false negative results of genetic testing are presented.

Prevalence of drug-resistant HIV-1 variants in untreated individuals in Europe: implications for clinical management.

BACKGROUND: Infection with drug-resistant human immunodeficiency virus type 1 (HIV-1) can impair the response to combination therapy. Widespread transmission of drug-resistant variants has the disturbing potential of limiting future therapy options and affecting the efficacy of postexposure prophylaxis. METHODS: We determined the baseline rate of drug resistance in 2208 therapy-naive patients recently and chronically infected with HIV-1 from 19 European countries during 1996-2002. RESULTS: In Europe, 1 of 10 antiretroviral-naive patients carried viruses with > or = 1 drug-resistance mutation. Recently infected patients harbored resistant variants more often than did chronically infected patients (13.5% vs. 8.7%; P=.006). Non-B viruses (30%) less frequently carried resistance mutations than did subtype B viruses (4.8% vs. 12.9%; P<.01). Baseline resistance increased over time in newly diagnosed cases of non-B infection: from 2.0% (1/49) in 1996-1998 to 8.2% (16/194) in 2000-2001. CONCLUSIONS: Drug-resistant variants are frequently present in both recently and chronically infected therapy-naive patients. Drug-resistant variants are most commonly seen in patients infected with subtype B virus, probably because of longer exposure of these viruses to drugs. However, an increase in baseline resistance in non-B viruses is observed. These data argue for testing all drug-naive patients and are of relevance when guidelines for management of postexposure prophylaxis and first-line therapy are updated.