RESUMEN
Blood donation screening for West Nile virus (WNV) was mandatory in the Lazio region in 2017 and 2018 (June-November) according to the national surveillance plan. In these years, all five donations reactive in WNV nucleic acid amplification tests harboured instead Usutu virus (USUV). Clade 'Europe 2' was identified in four blood donations and a 2018 mosquito pool. The cocirculation of WNV and USUV in Lazio warrants increased laboratory support and awareness of possible virus misidentification.
Asunto(s)
Donantes de Sangre/estadística & datos numéricos , Brotes de Enfermedades/prevención & control , Infecciones por Flavivirus/epidemiología , Flavivirus/aislamiento & purificación , Virus del Nilo Occidental/aislamiento & purificación , Adulto , Anciano , Animales , Culicidae/virología , Flavivirus/genética , Infecciones por Flavivirus/diagnóstico , Infecciones por Flavivirus/virología , Humanos , Italia/epidemiología , Masculino , Persona de Mediana Edad , Técnicas de Amplificación de Ácido Nucleico , Filogenia , Reacción en Cadena de la Polimerasa , Vigilancia de Guardia , Análisis de Secuencia , Virus del Nilo Occidental/genéticaRESUMEN
How the overlap between the hepatitis B virus (HBV) reverse transcriptase (RT) and HBV S antigen (HBsAg) genes modulates the extent of HBV genetic variability is still an open question, and was investigated here. The rate of nucleotide conservation (≤1% variability) followed an atypical pattern in the RT gene, due to an overlap between RT and HBsAg (69.9% nucleotide conservation in the overlapping region vs 41.2% in the non-overlapping region; P<0.001), with a consequently lower rate of synonymous substitution within the overlapping region [median(interquartile range)dS=3.1(1.5-7.4) vs 20.1(10.6-30.0); P=3.249×10(-22)]. The most conserved RT regions were located within the YMDD motif and the N-terminal parts of the palm and finger domains, critical for RT functionality. These regions also corresponded to highly conserved HBsAg domains that are critical for HBsAg secretion. Conversely, the genomic region encoding the HBsAg antigenic loop (where immune-escape mutations are localized) showed a sharp decrease in the extent of conservation (40.6%), which was less pronounced in the setting of human immunodeficiency virus (HIV)-driven immune suppression (48.8% in HIV-HBV co-infection vs 21.5% in mono-infected patients; P=0.020). In conclusion, the overlapping reading frame and the immune system appear to have shaped the patterns of RT and HBsAg genetic variability. Highly conserved regions in RT and HBsAg may deserve further attention as novel therapeutic targets.
Asunto(s)
Genoma Viral , Virus de la Hepatitis B/genética , Virus de la Hepatitis B/inmunología , Hepatitis B Crónica/genética , Hepatitis B Crónica/inmunología , Secuencia de Aminoácidos , Secuencia de Bases , Coinfección/genética , Coinfección/inmunología , Evolución Molecular , Variación Genética , VIH/genética , VIH/inmunología , Infecciones por VIH/genética , Infecciones por VIH/inmunología , Infecciones por VIH/virología , Antígenos de Superficie de la Hepatitis B/genética , Antígenos de Superficie de la Hepatitis B/inmunología , Hepatitis B Crónica/virología , Humanos , Datos de Secuencia Molecular , Mutación/inmunología , ADN Polimerasa Dirigida por ARN/genética , ADN Polimerasa Dirigida por ARN/inmunologíaRESUMEN
Specific HBsAg mutations are known to hamper HBsAg recognition by neutralizing antibodies thus challenging HBV-vaccination efficacy. Nevertheless, information on their impact and spreading over time is limited. Here, we characterize the circulation of vaccine-escape mutations from 2005 to 2019 and their correlation with virological parameters in a large cohort of patients infected with HBV genotype-D (N = 947), dominant in Europe. Overall, 17.7% of patients harbours ≥1 vaccine-escape mutation with the highest prevalence in subgenotype-D3. Notably, complex profiles (characterized by ≥2 vaccine-escape mutations) are revealed in 3.1% of patients with a prevalence rising from 0.4% in 2005-2009 to 3.0% in 2010-2014 and 5.1% in 2015-2019 (P = 0.007) (OR[95%CI]:11.04[1.42-85.58], P = 0.02, by multivariable-analysis). The presence of complex profiles correlates with lower HBsAg-levels (median[IQR]:40[0-2905]IU/mL for complex profiles vs 2078[115-6037]IU/ml and 1881[410-7622]IU/mL for single or no vaccine-escape mutation [P < 0.02]). Even more, the presence of complex profiles correlates with HBsAg-negativity despite HBV-DNA positivity (HBsAg-negativity in 34.8% with ≥2 vaccine-escape mutations vs 6.7% and 2.3% with a single or no vaccine-escape mutation, P < 0.007). These in-vivo findings are in keeping with our in-vitro results showing the ability of these mutations in hampering HBsAg secretion or HBsAg recognition by diagnostic antibodies. In conclusion, vaccine-escape mutations, single or in complex profiles, circulate in a not negligible fraction of HBV genotype-D infected patients with an increasing temporal trend, suggesting a progressive enrichment in the circulation of variants able to evade humoral responses. This should be considered for a proper clinical interpretation of HBsAg-results and for the development of novel vaccine formulations for prophylactic and therapeutic purposes.
Asunto(s)
Antígenos de Superficie de la Hepatitis B , Virus de la Hepatitis B , Humanos , Antígenos de Superficie de la Hepatitis B/genética , Vacunas contra Hepatitis B , Mutación , Vacunación , Genotipo , ADN Viral/genéticaRESUMEN
BACKGROUND: West Nile (WNV) and Usutu (USUV) are emerging vector-borne zoonotic flaviviruses. They are antigenically very similar, sharing the same life cycle with birds as amplification host, Culicidae as vector, and man/horse as dead-end host. They can co-circulate in an overlapping geographic range. In Europe, surveillance plans annually detect several outbreaks. METHODS: In Italy, a WNV/USUV surveillance plan is in place through passive and active surveillance. After a 2018 WNV outbreak, a reinforced integrated risk-based surveillance was performed in four municipalities through clinical and serological surveillance in horses, Culicidae catches, and testing on human blood-based products for transfusion. RESULTS: Eight WNV cases in eight equine holdings were detected. Twenty-three mosquitoe catches were performed and 2367 specimens of Culex pipiens caught; 17 pools were USUV positive. A total of 8889 human blood donations were tested, and two asymptomatic donors were USUV positive. CONCLUSIONS: Different surveillance components simultaneously detected WNV only in horses and USUV only in humans and mosquitoes. While in endemic areas (i.e. northern Italy) entomological surveillance is successfully used as an early detection warning, this method in central Italy seems ineffective. To achieve a high level of sensitivity, the entomological trapping effort should probably exceed a reasonable balance between cost and performance. Besides, WNV/USUV early detection can be addressed by horses and birds. Further research is needed to adapt the surveillance components in different epidemiological contexts.
Asunto(s)
Culex/virología , Infecciones por Flavivirus/veterinaria , Infecciones por Flavivirus/virología , Flavivirus/aislamiento & purificación , Mosquitos Vectores/virología , Fiebre del Nilo Occidental/veterinaria , Fiebre del Nilo Occidental/virología , Virus del Nilo Occidental/aislamiento & purificación , Animales , Culex/fisiología , Monitoreo Epidemiológico , Flavivirus/clasificación , Flavivirus/genética , Infecciones por Flavivirus/epidemiología , Infecciones por Flavivirus/transmisión , Enfermedades de los Caballos/epidemiología , Enfermedades de los Caballos/transmisión , Enfermedades de los Caballos/virología , Caballos , Humanos , Italia/epidemiología , Mosquitos Vectores/fisiología , Fiebre del Nilo Occidental/epidemiología , Fiebre del Nilo Occidental/transmisión , Virus del Nilo Occidental/clasificación , Virus del Nilo Occidental/genéticaRESUMEN
HBeAg is a marker of HBV-activity, and HBeAg-loss predicts a favorable clinical outcome. Here, we characterize HBeAg-levels across different phases of HBV infection, their correlation with virological/biochemical markers and the virological response to anti-HBV therapy. Quantitative HBeAg (qHBeAg, DiaSorin) is assessed in 101 HBeAg+ patients: 20 with acute-infection, 20 with chronic infection, 32 with chronic hepatitis and 29 with immunosuppression-driven HBV-reactivation (HBV-R). A total of 15/29 patients with HBV-R are monitored for >12 months after starting TDF/ETV. qHBeAg is higher in immunosuppression-driven HBV-R (median[IQR]:930[206-1945]PEIU/mL) and declines in chronic hepatitis (481[28-1393]PEIU/mL, p = 0.03), suggesting HBeAg production, modulated by the extent of immunological pressure. This is reinforced by the negative correlation between qHBeAg and ALT in acute infection (Rho = -0.66, p = 0.006) and chronic hepatitis (Rho = -0.35; p = 0.05). Interestingly, qHBeAg strongly and positively correlates with qHBsAg across the study groups, suggesting cccDNA as a major source of both proteins in the setting of HBeAg positivity (with limited contribution of integrated HBV-DNA to HBsAg production). Focusing on 15 patients with HBV-R starting TDF/ETV, virological suppression and HBeAg-loss are achieved in 60% and 53.3%. Notably, the combination of qHBeAg > 2000 PEIU/mL + qHBsAg > 52,000 IU/mL at HBV-R is the only factor predicting no HBeAg loss (HBeAg loss: 0% with vs. 72.7% without qHBeAg > 2000 PEIU/mL + qHBsAg > 52,000 IU/mL, p = 0.03). In conclusion, qHBeAg varies over the natural course of HBV infection, according to the extent of immunological pressure. In the setting of HBV-R, qHBeAg could be useful in predicting the treatment response under immunosuppression.
RESUMEN
Occult hepatitis B virus infection (OBI) is characterized by the presence of ongoing viral replication with very low levels of viremia (<200 IU/ml), and negativity for HBsAg, while the so-called 'false' OBI with higher levels of HBV-DNA that are negative for HBsAg are usually due to the occurrence of mutations of the HBsAg sequence that may alter the recognition by some immunoassays. We describe here a case of occult HBV infection that combines both aspects. A male patient with severe systemic diseases, positive for anti-HBc and anti-HBs and negative for all other HBV markers, including HBsAg, since at least 4 years, showed a positivity for HBeAg at a follow-up control in November 2008; HBV-DNA testing by real-time PCR evidenced very low levels of viremia (<40 IU/ml), direct sequencing of the surface antigen-coding and Pol/RT coding regions allowed the identification of genotype D, serotype adw2, one immune escape mutation (G145R) and no drug resistance mutations. The positivity for HBeAg could be attributed to a superinfection in a naturally immune subject or to reactivation of a latent infection; the mutated virus had a reduced fitness and was therefore able to replicate only at low levels, resulting in a mild form of occult HBV infection.
Asunto(s)
Anticuerpos contra la Hepatitis B/sangre , Antígenos e de la Hepatitis B/sangre , Virus de la Hepatitis B/genética , Virus de la Hepatitis B/inmunología , Hepatitis B/diagnóstico , Anciano , ADN Viral/sangre , ADN Viral/química , ADN Viral/genética , Genotipo , Hepatitis B/virología , Antígenos de Superficie de la Hepatitis B/sangre , Humanos , Masculino , Mutación Missense , Análisis de Secuencia de ADN , Carga ViralRESUMEN
BACKGROUND/AIMS: To investigate the different clusters of mutations associated with lamivudine resistance in HBV genotypes D and A. METHODS: HBV reverse transcriptase sequences of 89 HBV-infected patients failing lamivudine treatment were analyzed. The association of mutations with HBV genotypes was assessed by Chi-Squared test and multivariate logistic regression analysis. Covariate analysis was based on hierarchical clustering. RESULTS: In genotype A, the rtM204V (prevalence: 68.2%) was the main sign of lamivudine failure. Multivariate analysis confirmed that genotype A is the only predictor for rtM204V emergence (OR: 14.5 [95% CI: 1.3-158], P=0.02). Covariate analysis showed that rtM204V clusters with rtL180M, rtL229V (corresponding to sF220L in the HBsAg), and, interestingly, with HBsAg mutation sS207N (bootstrap=0.95). Both sF220L and sS207N co-localized in the fourth transmembrane HBsAg domain. In contrast, in genotype D the primary mutations rtM204V and rtM204I occurred with similar prevalence (39.1% versus 45.3%, P=0.47), and showed a distinct pattern of compensatory mutations. rtM204V clusters with mutations localized in the RT-B domain (rtV173L, rtL180M, and rtT184A/S) (bootstrap=0.94), while rtM204I clusters with mutations localized in the RT-A domain (rtS53N, rtT54Y, and rtL80I/V) (bootstrap=0.96) (without associations with HBsAg specific mutations). CONCLUSIONS: HBV genotype plays an important role in driving RT evolution under lamivudine treatment, and thus can be relevant for therapeutic sequencing, immunological response and disease progression.
Asunto(s)
Virus de la Hepatitis B/genética , Hepatitis B Crónica/tratamiento farmacológico , Lamivudine/uso terapéutico , Adulto , Alanina Transaminasa/sangre , Sustitución de Aminoácidos , Antivirales/uso terapéutico , Aspartato Aminotransferasas/sangre , Análisis por Conglomerados , Cartilla de ADN , ADN Viral/genética , ADN Viral/aislamiento & purificación , Farmacorresistencia Viral/efectos de los fármacos , Farmacorresistencia Viral/genética , Genotipo , Infecciones por VIH/complicaciones , Virus de la Hepatitis B/efectos de los fármacos , Virus de la Hepatitis B/enzimología , Hepatitis B Crónica/complicaciones , Hepatitis B Crónica/genética , Humanos , Persona de Mediana Edad , Reacción en Cadena de la Polimerasa , ADN Polimerasa Dirigida por ARN/genéticaRESUMEN
Chronic HBV + HDV infection is associated with greater risk of liver fibrosis, earlier hepatic decompensation, and liver cirrhosis hepatocellular carcinoma compared to HBV mono-infection. However, to-date no direct anti-HDV drugs are available in clinical practice. Here, we identified conserved and variable regions in HBsAg and HDAg domains in HBV + HDV infection, a critical finding for the design of innovative therapeutic agents. The extent of amino-acid variability was measured by Shannon-Entropy (Sn) in HBsAg genotype-d sequences from 31 HBV + HDV infected and 62 HBV mono-infected patients (comparable for demographics and virological-parameters), and in 47 HDAg genotype-1 sequences. Positions with Sn = 0 were defined as conserved. The percentage of conserved HBsAg-positions was significantly higher in HBV + HDV infection than HBV mono-infection (p = 0.001). Results were confirmed after stratification for HBeAg-status and patients' age. A Sn = 0 at specific positions in the C-terminus HBsAg were correlated with higher HDV-RNA, suggesting that conservation of these positions can preserve HDV-fitness. Conversely, HDAg was characterized by a lower percentage of conserved-residues than HBsAg (p < 0.001), indicating higher functional plasticity. Furthermore, specific HDAg-mutations were significantly correlated with higher HDV-RNA, suggesting a role in conferring HDV replicative-advantage. Among HDAg-domains, only the virus-assembly signal exhibited a high genetic conservation (75% of conserved-residues). In conclusion, HDV can constrain HBsAg genetic evolution to preserve its fitness. The identification of conserved regions in HDAg poses the basis for designing innovative targets against HDV-infection.
Asunto(s)
Evolución Molecular , Antígenos de Superficie de la Hepatitis B/genética , Virus de la Hepatitis B/genética , Hepatitis B/virología , Virus de la Hepatitis Delta/fisiología , Interacciones Microbianas , Adulto , Antivirales/farmacología , Coinfección , Femenino , Variación Genética , Genotipo , Hepatitis B/diagnóstico , Antígenos de Superficie de la Hepatitis B/química , Virus de la Hepatitis B/efectos de los fármacos , Humanos , Masculino , Persona de Mediana Edad , Modelos Moleculares , Mutación , Filogenia , Conformación Proteica , ARN Viral , Proteínas Virales/química , Proteínas Virales/genética , Proteínas Virales/metabolismoRESUMEN
RT-PCR is the most sensitive assay for diagnosis of influenza, due to enhanced rapidity and sensitivity as compared to classical methods. Hemi-nested RT-PCR was developed, targeting NP gene for influenza A and NS gene for influenza B, based on a previous single round RT-PCR method. The new method was compared with the previous technique for analytical sensitivity and specificity, and was applied to clinical samples from the lower and upper respiratory tract. The analytical sensitivity of hemi-nested RT-PCR was 10 (influenza A) and 4 times (influenza B) higher than the previous method. A high specificity of the new hemi-nested RT-PCR assay was observed by using whole respiratory viruses. When applied to lower respiratory tract specimens, the new method showed an increased rate of positivity as compared to the previous technique (9.3% versus 0.7% for influenza A, and 0.9% versus 0.2% for influenza B). Screening of upper respiratory tract samples collected during the seasonal 2005-2006 outbreak indicated 26.4% and 5.8% positivity for influenza A and B, respectively. The results were confirmed by sequence analysis: apart from influenza B, both influenza A subtypes H3N2 and H1N1, associated with the seasonal outbreak, were detected.
Asunto(s)
Virus de la Influenza A/aislamiento & purificación , Virus de la Influenza B/aislamiento & purificación , Gripe Humana/diagnóstico , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/métodos , Cartilla de ADN , Brotes de Enfermedades , Genes Virales , Humanos , Subtipo H1N1 del Virus de la Influenza A/genética , Subtipo H1N1 del Virus de la Influenza A/aislamiento & purificación , Subtipo H3N2 del Virus de la Influenza A/genética , Subtipo H3N2 del Virus de la Influenza A/aislamiento & purificación , Virus de la Influenza A/genética , Virus de la Influenza B/genética , Gripe Humana/epidemiología , Italia/epidemiología , Proteínas de la Nucleocápside , Nucleoproteínas/genética , Proteínas de Unión al ARN/genética , Sistema Respiratorio/virología , Estaciones del Año , Sensibilidad y Especificidad , Proteínas del Núcleo Viral/genética , Proteínas no Estructurales Virales/genéticaRESUMEN
BACKGROUND: An impaired HBsAg-secretion can increase HBV oncogenic-properties. Here, we investigate genetic-determinants in HBsAg correlated with HBV-induced hepatocellular carcinoma (HCC), and their impact on HBsAg-secretion and cell-proliferation. METHODS: This study included 128 chronically HBV-infected patients: 23 with HCC (73.9% D; 26.1% A HBV-genotype), and 105 without cirrhosis/HCC (72.4% D, 27.6% A) as reference-group. The impact of mutations on HBsAg-secretion was assessed by measuring the ratio [secreted/intracellular HBsAg] until day 5 post-transfection. The impact of mutations on cell-cycle advancement was assessed by flow-cytometry. RESULTS: Two HBsAg mutations significantly correlated with HCC: P203Q (17.4% [4/23] in HCC vs 1.0% [1/105] in non-HCC, P=0.004); S210R (34.8% [8/23] in HCC vs 3.8% [4/105] in non-HCC, P <0.001); P203Q+S210R (17.4% [4/23] in HCC vs 0% [0/110] in non-HCC, P=0.001). Both mutations reside in trans-membrane C-terminal domain critical for HBsAg-secretion. In in-vitro experiments, P203Q, S210R and P203Q+S210R significantly reduced the ratio [secreted/intracellular HBsAg] compared to wt at each time-point analysed (P <0.05), supporting an impaired HBsAg-secretion. Furthermore, P203Q and P203Q+S210R increased the percentage of cells in S-phase compared to wt, indicating cell-cycle progression (P203Q:26±13%; P203Q+S210R:29±14%; wt:18%±9, P <0.01. Additionally, S210R increased the percentage of cells in G2/M-phase (26±8% for wt versus 33±6% for S210R, P <0.001). CONCLUSIONS: Specific mutations in HBsAg C-terminus significantly correlate with HBV-induced HCC. They hamper HBsAg-secretion and are associated with increased cellular proliferation, supporting their involvement in HCC-development. The identification of viral genetic markers associated with HCC is critical to identify patients at higher HCC-risk that may deserve intensive liver monitoring, and/or early anti-HBV therapy.
Asunto(s)
Carcinoma Hepatocelular/patología , Antígenos de Superficie de la Hepatitis B/genética , Virus de la Hepatitis B/genética , Hepatitis B Crónica/patología , Neoplasias Hepáticas/patología , Mutación , Adulto , Anciano , Carcinoma Hepatocelular/virología , Ciclo Celular , Proliferación Celular , Femenino , Frecuencia de los Genes , Genotipo , Antígenos de Superficie de la Hepatitis B/metabolismo , Virus de la Hepatitis B/metabolismo , Virus de la Hepatitis B/fisiología , Hepatitis B Crónica/virología , Interacciones Huésped-Patógeno , Humanos , Neoplasias Hepáticas/virología , Masculino , Persona de Mediana Edad , Análisis Multivariante , Factores de RiesgoRESUMEN
BACKGROUND: The oncoprotein E6 binds to and degrades the p53 tumor suppressor protein, with different efficacy depending on the p53 codon 72 (arg/pro) polymorphism. The arg/arg allele has been shown to increase the risk for cervical cancer. MATERIALS AND METHODS: Fifty-eight women infected with HPV and 32 normal controls were analyzed by restriction fragment length polymorphism to detect arg/arg or arg/pro alleles. RESULTS: The allele frequencies in HPV-positive women were: arg/arg 47/58 (81%); arg/pro 9/58 (15.5%) and pro/pro 2/58 (3.4%), while those in controls were: arg/arg 19/32 (59%); arg/pro 10/32 (31.2%) and pro/pro 3/32 (9.3%) (Fisher's exact test, p = 0.068). The risk of having HSIL in arg/arg homozygous patients had odds ratio (OR) = 1.33 (95% CI 1.12-1.58, p = 0.628). Women with the arg/arg phenotype were at significantly increased risk for HPV infection; OR = 2.93 (95% CI 1.11-7.66, p = 0.028). Being homozygous arg/arg also substantially increased the risk of HR-HPV infection, with OR = 3.84 (95% CI 0.71-20.57, p = 0.128), whereas heterozygosity for arg/pro was protective against HR-HPV; OR = 0.186 (95% CI 0.03-1.04, p = 0.074). Allele frequencies in women with different HPV types were not significantly different, however (p = 0.174). CONCLUSION: These data suggest that arg/arg homozygous patients are at increased risk for HR-HPV infections.
Asunto(s)
Arginina/genética , Codón , Homocigoto , Infecciones por Papillomavirus/genética , Proteína p53 Supresora de Tumor/genética , Adolescente , Adulto , Anciano , Estudios de Casos y Controles , Femenino , Humanos , Italia/epidemiología , Persona de Mediana Edad , Factores de Riesgo , Proteína p53 Supresora de Tumor/químicaRESUMEN
Cell membrane protein (CMP) profile of HIV-1 from cerebrospinal fluid (CSF) and plasma of five AIDS patients with neurologic disorders was analyzed and compared with viral quasispecies composition in these body compartments. To this aim, paired CSF and plasma samples from AIDS subjects with HIV-related neurological diseases (three HIV-1 encephalopaty (HIVE) and two primary CNS lymphoma (PCNSL)) underwent immobilized antibody capture (IAC) assay to determine the profile of CMP acquired by HIV-1. The considered CMPs were CD45RO, CD26, CD36, glut-R, N-CAM, VCAM-1, ELAM-1, CD44 and CD58, representing lymphomonocyte, neuronal and adhesion molecules. Cloning and sequencing of env and gag regions was performed to predict coreceptor usage and to analyze quasispecies compartmentalization. The results indicated that CD44 and CD58 were the most represented molecules on HIV-1 from CSF, whereas CD36 was the most abundant molecule on plasma HIV-1. V3 env aminoacidic sequences and net charge were consistent with M-R5 phenotype in all CSF and in most plasma clones. The degree of genetic heterogeneity (both complexity and diversity) in p17 gag was significantly lower in CSF-HIV than that in plasma-HIV for three patients, higher for one patient, and not significantly different for one patient, suggesting compartmentalization for all but the latter patient. When considering the pattern of CMP, the most abundant CMP observed in HIV from plasma and CSF was different in patients showing compartmentalization, while was the same in the patient without significant differences in CSF and plasma quasispecies. In conclusion, the present data on CMP pattern, V3 loop aminoacidic signature and genetic heterogeneity of HIV-1 quasispecies from CSF and plasma of HIVE patients, are consistent with a compartmentalized virus replication, at least in some patients, and with a possible different source of HIV in the two body sites, even though in a context of a largely prevalent M-R5 phenotype.
Asunto(s)
Síndrome de Inmunodeficiencia Adquirida/complicaciones , Compartimento Celular/fisiología , VIH-1/patogenicidad , Proteínas de la Membrana/sangre , Proteínas de la Membrana/líquido cefalorraquídeo , Enfermedades del Sistema Nervioso/virología , Complejo SIDA Demencia/sangre , Complejo SIDA Demencia/líquido cefalorraquídeo , Complejo SIDA Demencia/etiología , Complejo SIDA Demencia/virología , Síndrome de Inmunodeficiencia Adquirida/virología , Adulto , Femenino , Productos del Gen gag/sangre , Productos del Gen gag/líquido cefalorraquídeo , Productos del Gen gag/genética , Variación Genética , VIH-1/genética , VIH-1/aislamiento & purificación , Humanos , Masculino , Enfermedades del Sistema Nervioso/sangre , Enfermedades del Sistema Nervioso/líquido cefalorraquídeo , Enfermedades del Sistema Nervioso/etiología , Proteínas Virales/sangre , Proteínas Virales/líquido cefalorraquídeo , Replicación ViralRESUMEN
OBJECTIVE: To describe an outbreak of hepatitis C virus (HCV). DESIGN: Retrospective cohort study. SETTING: Outpatient department of a hospital in Rome, Italy. PATIENTS: All 42 patients exposed to ozone therapy by autohemotherapy or intramuscular injection from January to June 2001. METHODS: Epidemiologic investigation, serologic analysis, and virus genotyping. RESULTS: Thirty-one (74%) of the patients agreed to participate in the study. Three (9.7%) had symptoms of HCV infection. This incidence rate was higher than the rate of 1.4 per 100,000 per year in the regional population. Six patients were positive for HCV antibodies and HCV RNA for a prevalence rate of 19.4%, which was much higher than the estimate of 0.9% in the population. Virus genotype 1b was found in two case-patients (one symptomatic) and 2c in four case-patients (two symptomatic), one of whom was known to have an HCV infection since 1986 and could have been the source of infection. The infected patients were all being exposed to ozone-enriched transfusions of autologous blood. Although the specific mode of transmission between patients was not detected, transmission probably occurred during one of the three busiest therapeutic sessions in the 6-month period. CONCLUSIONS: Transmission of HCV infection may occur during medical procedures with limited bleeding. Standard precautions must be applied in any healthcare setting; restricting the number of individuals treated during each therapeutic session could be an effective way of avoiding accidental transmission of infection.
Asunto(s)
Transfusión de Sangre Autóloga , Infección Hospitalaria/epidemiología , Brotes de Enfermedades , Hepatitis C/epidemiología , Ozono/uso terapéutico , Adulto , Anciano , Femenino , Genotipo , Hepacivirus/clasificación , Hepacivirus/genética , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Prevalencia , ARN Viral/análisis , Estudios Retrospectivos , Ciudad de Roma/epidemiologíaRESUMEN
BACKGROUND: To define HBsAg-mutations correlated with different serum HBV-DNA levels in HBV chronically-infected drug-naive patients. METHODS: This study included 187 patients stratified into the following ranges of serum HBV-DNA:12-2000 IU/ml, 2000-100,000 IU/ml, and >100,000 IU/ml. HBsAg-mutations were associated with HBV-DNA levels by applying a Bayesian-Partitional-Model and Fisher-exact test. Mutant and wild-type HBV genotype-D genomes were expressed in Huh7 cells and HBsAg-production was determined in cell-supernatants at 3 days-post-transfection. RESULTS: Specific HBsAg-mutations (M197T,-S204N-Y206C/H-F220L) were significantly correlated with serum HBV-DNA <2000 IU/ml (posterior-probability>90%, P < 0.05). The presence of Y206C/H and/or F220L was also associated with lower median (IQR) HBsAg-levels and lower median (IQR) transaminases (for HBsAg:250[115-840] IU/ml for Y206C/H and/or F220L versus 4300[640-11,838] IU/ml for wild-type, P = 0.023; for ALT:28[21-40] IU/ml versus 53[34-90] IU/ml, P < 0.001). These mutations were localized in the HBsAg C-terminus, known to be involved in virion and/or HBsAg secretion. The co-occurrence of Y206C + F220L was found significant by cluster-analysis, (P = 0.02). In addition, in an in-vitro model Y206C + F220L determined a 2.8-3.3 fold-reduction of HBsAg-amount released in supernatants compared to single mutants and wt (Y206C + F220L = 5,679 IU/ml; Y206H = 16,305 IU/ml; F220L = 18,368 IU/ml; Y206C = 18,680 IU/ml; wt = 14,280 IU/ml, P < 0.05). CONCLUSIONS: Specific HBsAg-mutations (compartmentalized in the HBsAg C-terminus) correlated with low-serum HBV-DNA and HBsAg-levels. These findings can be important to understand mechanisms underlying low HBV replicative potential including the inactive-carrier state.
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ADN Viral/sangre , Antígenos de Superficie de la Hepatitis B/genética , Virus de la Hepatitis B/genética , Hepatitis B Crónica/virología , Adulto , Teorema de Bayes , Portador Sano/virología , Femenino , Genotipo , Antígenos de Superficie de la Hepatitis B/sangre , Antígenos de Superficie de la Hepatitis B/química , Humanos , Masculino , Persona de Mediana Edad , Modelos Moleculares , Datos de Secuencia Molecular , Mutagénesis Sitio-Dirigida , Mutación , Transaminasas/sangreRESUMEN
The aim of the study was to characterize the interferon sensitivity determining region (ISDR) mutation pattern and its changes at 4 weeks of treatment in a population of patients infected with hepatitis C virus (HCV) genotype 1b receiving standard or PEG-IFN plus ribavirin (RBV), to find possible early correlates of therapy outcome. Forty-five patients with chronic hepatitis due to HCV 1b were treated by PEG-IFN-alpha2b (n=23) or IFN-alpha2b (n=22) plus RBV 1000-1200 mg/day. They were classified 24 weeks after stopping therapy as sustained responders (SR), relapsers (REL) or non-responders (NR). Sixteen patients were SR, 12 REL and 17 NR. ISDR mutations were evaluated by direct sequencing at baseline in all and after 4 weeks in patients with detectable viraemia (n=30). The frequency of the three ISDR types was 26.7% wild-type, 64.4% intermediate-type and 8.9% mutant-type, without significant difference in their frequency in SR, REL and NR, independent of IFN formulation. Average numbers of mutations in SR, REL and NR were 1.88 +/- 0.54, 1.33 +/- 0.33 and 0.94 +/- 0.25, respectively, P>0.05. The baseline number of ISDR mutations was not related to the extent of viral load decline in the first month of therapy. Sequence analysis of ISDR region performed 4 weeks after starting therapy revealed qualitative or quantitative changes of ISDR sequence in only seven patients, without correlation with response. Thus, in our patients the baseline pattern of ISDR was unrelated to treatment outcome. Selection towards a dominant IFN-resistant strain did not occur under standard or PEG-IFN plus RBV.
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Antivirales/uso terapéutico , Hepacivirus/genética , Hepatitis C Crónica/tratamiento farmacológico , Interferón-alfa/uso terapéutico , Polietilenglicoles/uso terapéutico , Ribavirina/uso terapéutico , Secuencia de Aminoácidos , Estudios de Cohortes , Quimioterapia Combinada , Femenino , Genotipo , Hepacivirus/efectos de los fármacos , Humanos , Interferón alfa-2 , Masculino , Persona de Mediana Edad , Datos de Secuencia Molecular , Mutación , Proteínas Recombinantes , Alineación de Secuencia , Resultado del Tratamiento , Proteínas no Estructurales Virales/genéticaRESUMEN
A cluster of HIV-1 infection has been identified in Libya in 1999, involving 402 children admitted to "El-Fath" Children's Hospital in Benghazi (BCH) during 1998 and 19 of their mothers. Nosocomial transmission has been indicated as responsible for the spread of infection. Out of this group, 104 children and 19 adult women have been followed at the National Institute for Infectious Diseases L. Spallanzani in Rome during 1 year. At BCH, all children had received intravenous infusions but not blood or blood products. A single child receiving a blood transfusion in 1997 and the 17 infected mothers were never hospitalized in Benghazi. In addition, two nurses were diagnosed as HIV-1 infected. In 40 subjects out of this group HIV-1 gag, env, and pol fragments were amplified and sequenced. The phylogenetic analyses showed that a monophyletic recombinant HIV-1 form CRF02-AG was infecting all of the HIV-1-seropositive patients admitted at BCH with no close similarities to the other CRF02-AG reported to GenBank. A different strain was found in the child infected by blood transfusion. The data thus suggest a highly contagious nosocomial spread of HIV-1 infection and possibly transmission of the virus from child to mother during breastfeeding in connection with primary HIV-1 infection.
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Infección Hospitalaria/virología , Brotes de Enfermedades , VIH-1/clasificación , Adolescente , Adulto , Secuencia de Bases , Niño , Preescolar , Femenino , VIH-1/genética , Humanos , Libia/epidemiología , Datos de Secuencia MolecularRESUMEN
INTRODUCTION: The identification of novel reverse-transcriptase (RT) drug-resistance mutations is critical in predicting the probability of success to anti-HBV treatment. Furthermore, due to HBV-RT/HBsAg gene-overlap, they can have an impact on HBsAg-detection and quantification. METHODS: 356 full-length HBV-RT sequences from 197 drug-naive patients and 159 patients experiencing virological-breakthrough to nucleoside/nucleotide-analogs (NUCs) were analyzed. Mutants and wild-type HBs-antigens were expressed in HuH7-hepatocytes and quantified in cell-supernatants and cell-lysates by Architect HBsAg-assay. RESULTS: Ten novel RT-mutations (rtN53T-rtS78T-rtS85F-rtS135T-rtA181I-rtA200V-rtK212Q-rtL229V/F-rtM309K) correlated with specific NUC-treatments and classical drug-resistance mutations on divergent evolutionary pathways. Some of them reduced RT-binding affinity for anti-HBV drugs and altered S-antigen structure. Indeed, rtS78T (prevalence: 1.1% in drug-naïve and 12.2% in adefovir-failing patients) decreased the RT-affinity for adefovir more than the classical adefovir-resistance mutations rtA181 T/V (WT:-9.63 kcal/mol, rtA181T:-9.30 kcal/mol, rtA181V:-7.96 kcal/mol, rtS78T:-7.37 kcal/mol). Moreover, rtS78T introduced a stop-codon at HBsAg-position 69, and completely abrogated HBsAg-quantification in both supernatants and cell-lysates, indicating an impaired HBsAg-secretion/production. Furthermore, the HBsAg-mutation sP217L, silent in RT, significantly correlated with M204V/I-related virological-breakthrough and increased HBsAg-quantification in cell-lysate. CONCLUSIONS: Mutations beyond those classically known can affect drug-binding affinity of mutated HBV-RT, and may have potential effects on HBsAg. Their cumulative effect on resistance and HBV-pathogenicity indicates the importance of preventing therapeutic failures.
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Antígenos de Superficie de la Hepatitis B/análisis , Virus de la Hepatitis B/efectos de los fármacos , Hepatitis B/tratamiento farmacológico , Mutación , ADN Polimerasa Dirigida por ARN/genética , Inhibidores de la Transcriptasa Inversa/administración & dosificación , Adenina/administración & dosificación , Adenina/análogos & derivados , Adenina/farmacología , Adulto , Línea Celular , Codón sin Sentido , Farmacorresistencia Viral , Femenino , Expresión Génica , Antígenos de Superficie de la Hepatitis B/genética , Hepatocitos/virología , Humanos , Masculino , Persona de Mediana Edad , Organofosfonatos/administración & dosificación , Organofosfonatos/farmacología , Unión Proteica , ADN Polimerasa Dirigida por ARN/metabolismo , Inhibidores de la Transcriptasa Inversa/metabolismo , Inhibidores de la Transcriptasa Inversa/farmacología , Selección Genética , Insuficiencia del TratamientoRESUMEN
Occult HBV infection (OBI) is a threat for the safety of blood-supply, and has been associated with the onset of HBV-related hepatocellular carcinoma and lymphomagenesis. Nevertheless, genetic markers in HBsAg (particularly in D-genotype, the most common in Europe) significantly associated with OBI in vivo are missing. Thus, the goal of this study is to define: (i) prevalence and clinical profile of OBI among blood-donors; (ii) HBsAg-mutations associated with OBI; (iii) their impact on HBsAg-detection. OBI was searched among 422,278 blood-donors screened by Nucleic-Acid-Testing. Following Taormina-OBI-definition, 26 (0.006%) OBI-patients were identified. Despite viremia <50IU/ml, HBsAg-sequences were obtained for 25/26 patients (24/25 genotype-D). OBI-associated mutations were identified by comparing OBI-HBsAg with that of 82 chronically-infected (genotype-D) patients as control. Twenty HBsAg-mutations significantly correlated for the first time with OBI. By structural analysis, they localized in the major HBV B-cell-epitope, and in HBsAg-capsid interaction region. 14/24 OBI-patients (58.8%) carried in median 3 such mutations (IQR:2.0-6.0) against 0 in chronically-infected patients. By co-variation analysis, correlations were observed for R122P+S167L (phi=0.68, P=0.01), T116N+S143L (phi=0.53, P=0.03), and Y100S+S143L (phi=0.67, p<0.001). Mutants (obtained by site-directed mutagenesis) carrying T116N, T116N+S143L, R122P, R122P+Q101R, or R122P+S167L strongly decreased HBsAg-reactivity (54.9±22.6S/CO, 31.2±12.0S/CO, 6.1±2.4S/CO, 3.0±1.0S/CO and 3.9±1.3S/CO, respectively) compared to wild-type (306.8±64.1S/CO). Even more, Y100S and Y100S+S143L supernatants show no detectable-HBsAg (experiments in quadruplicate). In conclusions, unique HBsAg-mutations in genotype-D, different than those described in genotypes B/C (rarely found in western countries), tightly correlate with OBI, and strongly affect HBsAg-detection. By altering HBV-antigenicity and/or viral-particle maturation, they may affect full-reliability of universal diagnostic-assays for HBsAg-detection.
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Antígenos de Superficie de la Hepatitis B/genética , Virus de la Hepatitis B/genética , Hepatitis B/diagnóstico , Femenino , Marcadores Genéticos , Genotipo , Hepatitis B/epidemiología , Antígenos de Superficie de la Hepatitis B/química , Humanos , Masculino , Persona de Mediana Edad , Modelos Moleculares , Mutación , Fenotipo , Prevalencia , Conformación ProteicaRESUMEN
BACKGROUND: Impact of hepatitis B virus genetic barrier, defined as the number and type of nucleotide substitutions required to overcome drug/immune selective pressure, on drug-resistance/immune-escape development is unknown. METHODS: Genetic barrier was calculated according to Van de Vijver (2006) in 3482 hepatitis B virus-reverse transcriptase/HBV surface antigen sequences from 555 drug-naïve patients and 2927 antiviral-treated patients infected with hepatitis B virus genotypes A-G. RESULTS: Despite high natural variability, genetic barrier for drug-resistance development is identical amongst hepatitis B virus genotypes, but varies according to drug-resistance mutation type. Highest genetic barrier is found for secondary/compensatory mutations (e.g. rtL80I/V-rtL180M-rtV173L), whilst most primary mutations (including rtM204V-rtA181T/V-rtI169T-rtA194T) are associated with low genetic barrier. An exception is rtM204I, which can derive from a transition or a transversion. Genotypes A and G are more prone to develop immune/diagnostic-escape mutations sT114R and sG130N. Vaccine-escape associated sT131N-mutation is a natural polymorphism in both A and G genotypes. CONCLUSION: Genetic barrier and reverse transcriptase/HBV surface antigen overlapping can synergistically influence hepatitis B virus drug-resistance/immune-escape development. The different immune-escape potential of specific hepatitis B virus genotypes could have important clinical consequences in terms of disease progression, vaccine strategies and correct HBV surface antigen detection.