Validation of a sensitive and specific real-time PCR for detection and quantitation of hepatitis B virus covalently closed circular DNA in plasma of chronic hepatitis B patients.

Hepatitis B virus (HBV) covalently closed circular DNA (cccDNA) serves as a template for viral replication and plays a role in persistence of HBV infection. The origin and significance of cccDNA in plasma, however, are not well understood. A sensitive, specific, and reproducible real-time PCR for detection and quantitation of cccDNA in plasma of chronic hepatitis B patients was developed and validated. Four HBV DNA reference panels and 96 plasma samples of chronic hepatitis B patients are analyzed. Results are compared with total HBV DNA levels. This cccDNA assay had a lower limit of detection at 15 copies/PCR, a lower limit of quantitation at 91 copies/PCR, and a correlation coefficient (R) of 0.98 (p < 0.0001). HBV cccDNA can be detected in two of four international panels. Significant correlation is found between cccDNA and total HBV DNA levels in both panels (R = 0.96 and R = 0.43) and in samples of the chronic hepatitis B patients (R = 0.88, p < 0.0001). In 57 % of these samples cccDNA can be detected. Mean level of cccDNA is 0.16 % of total HBV load. Plasma HBV cccDNA levels are higher in HBeAg-positive samples than in HBeAg-negative samples (p < 0.0001). Total HBV DNA levels and HBV genotype do not influence cccDNA detection.

Genetic variation in IL28B and treatment outcome in HBeAg-positive and -negative chronic hepatitis B patients treated with Peg interferon alfa-2a and adefovir.

In a cohort of 95 chronic hepatitis B patients, who were treated with peg-interferon and adefovir for 1 year, and who had 15% HBsAg loss (overall), no association was found between IL28B polymorphisms and HBeAg seroconversion or HBsAg clearance. These findings suggest that any association with outcome, if present, is less than that seen in chronic hepatitis C. Additional studies are needed to enlarge sample size and to refine our understanding of IL28B biology in the context of chronic hepatitis B response to immunomodulatory and direct antiviral therapy.

Validation of a sensitive and specific real-time PCR for detection and quantitation of hepatitis B virus covalently closed circular DNA in plasma of chronic hepatitis B patients.

Hepatitis B virus (HBV) covalently closed circular DNA (cccDNA) serves as a template for viral replication and plays a role in persistence of HBV infection. The origin and significance of cccDNA in plasma however, is not well understood. A sensitive, specific, and reproducible real-time PCR for detection and quantitation of cccDNA in plasma of chronic hepatitis B patients was developed and validated. Four HBV DNA reference panels, and 96 plasma samples of chronic hepatitis B patients were analyzed. Results were compared with total HBV DNA levels, individual ALT levels and the Histology Activity Index (HAI). This cccDNA assay had a lower limit of detection at 15 copies/PCR, a lower limit of quantitation at 91 copies/PCR and a correlation coefficient (R) of 0.98 (P < 0.0001). cccDNA was detected in two of four international panels. Significant correlation was found between cccDNA and total HBV DNA levels in both panels (R = 0.96, and R = 0.43) and in samples of the chronic hepatitis B patients (R = 0.88, P < 0.0001). In 57% of these samples cccDNA was detectable. Mean level of cccDNA was 0.16% of total HBV load. Plasma cccDNA levels were higher in HBeAg positive samples than in HBeAg negative samples (4.91 log copies/ml vs. 3.88 log copies/ml, P < 0.0001). Levels of total HBV DNA and HBV genotype did not influence cccDNA detection. ALT levels and HAI-score were not correlated with plasma cccDNA levels. These findings suggest that cccDNA levels in plasma are not the result of increased hepatocyte degeneration, but indicate that other mechanisms might be responsible.

Development of an internally controlled real-time PCR assay for detection of Chlamydophila psittaci in the LightCycler 2.0 system.

A real-time PCR assay with a DNA purification and inhibition control (internal control; IC) was developed to detect Chlamydophila psittaci DNA in human clinical samples. Novel C. psittaci-specific primers targeting the ompA gene were developed. The IC DNA contained the same primer-binding sites and had the same length and nucleotide content as the C. psittaci DNA amplicon, but had a shuffled probe-binding region. The lower limit of detection was 80 target copies/PCR, corresponding to 6,250 copies/mL in a clinical sample. Specificity was tested using reference strains of 30 bacterial species. No amplification was observed from any of these samples. Respiratory samples from eight patients were positive with this PCR. Six of these patients were confirmed as positive for C. psittaci with serological testing. Two patients had increasing antibody titres, but did not fulfil criteria proposed previously for serologically proven Chlamydia spp. infection. The real-time PCR described in this paper is a sensitive, specific and rapid method to detect C. psittaci DNA in human clinical respiratory samples.

Human parechovirus infections in Dutch children and the association between serotype and disease severity.

BACKGROUND: Human parechoviruses (HPeVs) are members of the family Picornaviridae and are classified into 3 known serotypes: HPeV1, HPeV2, and the recently identified HPeV3. HPeV1 and HPeV2 infections are most commonly associated with mild respiratory or gastrointestinal symptoms and occasionally with severe disease conditions, such as flaccid paralysis and encephalitis. HPeV3 infection has been associated with transient paralysis and neonatal infection and has until now only been reported in Japan and Canada. METHODS: Culture isolates considered to be enterovirus on the basis of cell culture but that were found to be enterovirus negative by 5' untranslated region reverse-transcriptase polymerase chain reaction (5'UTR RT-PCR) during the period December 2000 through January 2005 were selected. Isolates were tested by HPeV 5'UTR RT-PCR and were genotyped by sequencing the VP1 region. Phylogenetic analysis was performed, and the association with clinical symptoms was established. RESULTS: Thirty-seven (12%) of the 303 isolates that tested positive for enterovirus by cell culture were in fact HPeV. The majority of the HPeV-positive isolates (n = 27) could be identified as HPeV1. The remaining 10 isolates, which were grown from samples obtained in 2001, 2002, and 2004, could be typed as the recently identified HPeV3. HPeV was exclusively detected in children aged < 3 years. Children infected with HPeV3 were significantly younger than children infected with HPeV1, and sepsis-like illness and central nervous system involvement were more frequently reported in children infected with HPeV3. CONCLUSIONS: We report HPeV infections in young children during the period of 2000-2005 and show an association between HPeV3 infection and sepsis-like illness and central nervous system involvement in neonates.

Occult hepatitis B virus infection before and 1 year after start of HAART in HIV type 1-positive patients.

Occult hepatitis B virus (HBV) infection is diagnosed when HBc antibodies and HBV-DNA are detectable in serum while hepatitis B surface antigen (HBsAg) is not. The clinical relevance of this phenomenon in HIV-1 patients starting highly active antiretroviral therapy (HAART) is unknown. We followed 93 therapy naive HIV-1-infected adults who were anti-HBc positive, HBsAg and HBeAg negative, during first year of HAART. At baseline, HBV-DNA was quantified, and HBV genotype was determined in the HBV-DNA-positive patients by sequencing a part of the HBV genome. Four of 93 patients (4%) were HBV DNA positive at baseline. All four patients tested negative for HBV-DNA after 1 year. They all received lamivudine as part of their HAART. They had no clinically significant liver enzyme elevations (LEE) during the first year of HAART. Two of the patients had a genotype A, one genotype E, and in the fourth patient sequencing was not possible. In one patient we found significant mutations in the a determinant region of HBsAg, at positions 142 and 144. In our population of therapy-naive HIV-1-infected adults who were anti-HBc positive, we found occult HBV infection in 4% of the patients. We did not find an increased risk for LEE in our population of patients after the start of HAART. Our results illustrate that occult HBV infection is more a diagnostic than a clinical problem. It may be caused by very low levels of HBV replication, concurrent presence of HBsAg and anti-HBs, or mutations in the HBsAg a determinant.

[Sexual transmission of hepatitis C in homosexual men]. / Seksuele overdracht van hepatitis C bij homoseksuele mannen.

An acute hepatitis C infection was diagnosed in three HIV-positive gay men, aged 43, 48 and 30 years, respectively. In all three, unprotected sexual intercourse and fisting was a universal risk factor for the infection. They all denied having used drugs intravenously, which is the most common risk factor. The third man had a documented proctitis (lymphogranuloma venereum) at the time when the HCV transmission must have taken place. No serious complications occurred during the acute HCV infection. Because the infection did not resolve spontaneously after a few months, all three men were treated with pegylated interferon and ribavirin. Recently, the number of cases of acute HCV infection has been seen to increase in The Netherlands. This may be due primarily to an increase in unprotected sexual intercourse and fisting. This hypothesis is supported by a documented increased prevalence of sexually transmissible diseases among gay men in The Netherlands. As acute infections may turn into chronic infections, treatment of an acute infection should be considered in order to prevent the chronic disease.