An analysis of the predictive value of the HIV Ag/Ab screening assay within the performance characteristics of the DiaSorin LIAISON XL for the detection of blood-borne viruses.

BACKGROUND: Correct identification of blood borne viral infections, such as hepatitis B virus (HBV), hepatitis C virus (HCV) and human immunodeficiency virus (HIV) is crucial in detection and follow up of infection in patients. OBJECTIVES: We evaluated the diagnostic performance of the DiaSorin LIAISON XL (LIAISON XL) for screening of HBV, HCV and HIV infection. In addition, we investigated the variability of the signal-to-cuttoff ratio (S/CO) of the LIAISON XL HIV Ag/Ab assay and it's predictive value in subsequent confirmation of HIV-1 infection. STUDY DESIGN: We analyzed 16,497 blood samples on which HBV, HCV and HIV screening was performed. We defined A) archived samples previously tested with an arbitrary result in the Abbott ARCHITECT i2000SR system; B) prospectively collected samples which were simultaneously tested on the LIAISON XL and ARCHITECT i2000SR; C) prospectively collected serum samples for HIV testing which were tested solely on the LIAISON XL. RESULTS: The agreements of HBV-, HCV-, and HIV markers between the two compared systems are remarkably high. Among the samples which were prospectively tested for HIV Ab/Ag on the LIASON XL, 229 (1.6%) were reactive of which 141 (61.6%) could be confirmed. Increasing the signal-to-cutoff value to 4 could increase the positive predictive value (PPV) to 88.1% without decreasing sensitivity. CONCLUSIONS: The LIAISON XL system proved to be an excellent system for diagnosing HBV, HCV, and HIV. Our data for the first time showed that increasing the HIV S/CO ratio was safe and increased the PPV for confirmed HIV infection in the tested population.

A 5-year study of adenoviruses causing conjunctivitis in Izmir, Turkey.

Adenoviruses are a common cause of conjunctivitis. Genotypes are diverse and differ according to population and geographical distribution of the virus. There is limited data regarding ocular adenoviral infections and genotype distribution in Turkey. This study aimed to determine the adenovirus genotypes and their epidemiological features among patients with conjunctivitis between 2006 and 2010, in Izmir, Turkey. Adenoviral DNA was detected by PCR in 213 of 488 (44%) of the ocular samples collected from patients with viral conjunctivitis during the 5-year study period. Of these, 101 (47%) were randomly chosen and genotyped by sequence analysis. Seven genotypes were identified, including 3, 4, 8, 11, 19, 37, and 53. Genotype 8 and 4 were the dominant types detected in 67 (66.3%) and 25 (24.7%) of the samples, respectively. Other five genotypes (3, 11, 19, 37, 53) were detected in 9 (8.9%) samples. Genotype and seasonal differences observed throughout the study. Human adenoviruse (HAdV)-8 was the most frequent type, except 2008. The prevalence of genotype 4 increased starting from 2006, became dominant in 2008 and decreased in the following years. The peak season was mostly spring months, although it was possible to detect positive samples throughout the year. In conclusion, genotype 8 followed by genotype 4 was the most frequent adenoviral types causing conjunctivitis during the 5-year study period. Findings suggest that there is a slow shift between genotypes throughout the years.

Virological failure and drug resistance during first line anti-retroviral treatment in Indonesia.

The virological response and development of drug resistance during first-line anti-retroviral treatment (ART) were studied in Indonesia where the majority of patients infected with HIV have a history of injecting drug use, which is often linked with lower treatment adherence and development of drug-resistance. As many as 575 patients starting ART between September 2007 and March 2010 in Hasan Sadikin Hospital Bandung were followed prospectively. Clinical and laboratory monitoring was performed every 6 months. Plasma samples with HIV-RNA ≥ 400 copies/ml were examined for drug resistance mutations. Most patients were male (72.3%), 59.7% had a history of injecting drug use, and the median CD4+ cells count before start of ART was 35 cells/mm(3) (IQR 10-104). From 438 HIV patients with HIV-RNA measurements, 40 (9.1%) subjects had HIV-RNA ≥ 400 copies/ml after 24 weeks (median follow-up 16 (IQR 8-25) months). Of these failing patients 16 (47%) subjects had drug resistance mutations, predominantly M184V (35.3%), Y181C (23.5%), K103N (11.7%), and TAMs (11.7%). A history of treatment discontinuation ≥ 1 month, reported by 5.3% (23) of patients, was strongly associated with virological failure (adjusted OR 12.64, 95% CI 4.51-35.41); and a history of injecting drug use was not (OR 0.75, 95% CI 0.38-1.46). This is the largest and most systematic evaluation of virological response to first line ART in Indonesia. Patients in this cohort responded well to first line ART, with low rates of virological failure and drug resistance. A history of injecting drug use should not be a reason to withhold ART in this setting.

HIV-2 encephalitis: case report and literature review.

We report the case of a 59-year-old man who moved from Cape Verde to Massachusetts at the age of 29. He had multiple sexual contacts with female partners in Cape Verde and with West African women in Massachusetts, as well as multiple past indeterminate HIV-1 antibody tests. He presented to our facility with 2-3 months of inappropriate behaviors, memory impairment, weight loss, and night sweats, at which time he was found to have an abnormal enhancing lesion of the corpus collosum on brain magnetic resonance imaging (MRI). Laboratory testing revealed a CD4 count of 63 cells/mm(3), positive HIV-2 Western blot, serum HIV-2 RNA polymerase chain reaction (PCR) of 1160 copies per milliliter and cerebrospinal fluid (CSF) HIV-2 RNA PCR of 2730 copies per milliliter. Brain biopsy demonstrated syncytial giant cells centered around small blood vessels and accompanied by microglia, which correlated with prior pathologic descriptions of HIV-2 encephalitis and with well-described findings of HIV-1 encephalitis. Based on genotype resistance assay results, treatment guidelines, and prior studies validating success with lopinavir-ritonavir, he was treated with tenofovir-emtricitabine and lopinavir-ritonavir, which has led to virologic suppression along with steady neurologic and radiologic improvement, although he continues to have deficits.

Population genetic tests suggest that the epidemiologies of JCV and BKV are strikingly different.

The JCV and BKV viruses have been used as markers for the study of human evolution by assuming that these viruses coevolved with their host. However, it is currently unclear whether the details of the population expansion of these viruses and humans agree. To study this in more detail, large numbers of complete genomes were used for population genetic tests to detect evidence for population expansion. Relative to the neutral expectation of no selective forces and no demographic changes, the JCV data set contained a striking excess of synonymous and non-synonymous mutations that occur only once in the data set. The same was found for non-synonymous mutations of BKV, but not at all for synonymous mutations of BKV. The different frequency spectra of mutations in JCV and BKV do not result from the inclusion of patients with clinical symptoms associated with BKV and JCV, such as nephropathy or progressive multifocal leucoencefalopathy, nor from the different numbers of genomes available for JCV and BKV. Instead, the distribution of unique mutations and population genetic models that use older mutation classes indicate a striking difference of the historical demographies of JCV and BKV with only the former virus exhibiting the evidence of demographic expansion. Our analyses expand on recent population genetic analyses that document a global population expansion of JCV by taking into account the impact of deleterious mutations and by comparing both human viruses. The striking difference between the demographics of BKV and JCV suggests that important aspects of their epidemiology remain to be discovered.

The effect of primer-template mismatches on the detection and quantification of nucleic acids using the 5' nuclease assay.

Real-time polymerase chain reaction (PCR) is the current method of choice for detection and quantification of nucleic acids, especially for molecular diagnostics. Complementarity between primers and template is often crucial for PCR applications, as mismatches can severely reduce priming efficiency. However, little quantitative data on the effect of these mismatches is available. We quantitatively investigated the effects of primer-template mismatches within the 3'-end primer region on real-time PCR using the 5'-nuclease assay. Our results show that single mismatches instigate a broad variety of effects, ranging from minor (<1.5 cycle threshold, eg, A-C, C-A, T-G, G-T) to severe impact (>7.0 cycle threshold, eg, A-A, G-A, A-G, C-C) on PCR amplification. A clear relationship between specific mismatch types, position, and impact was found, which remained consistent for DNA versus RNA amplifications and Taq/Moloney murine leukemia virus versus rTth based amplifications. The overall size of the impact among the various master mixes used differed substantially (up to sevenfold), and for certain master mixes a reverse or forward primer-specific impact was observed, emphasizing the importance of the experimental conditions used. Taken together these data suggest that mismatch impact follows a consistent pattern and enabled us to formulate several guidelines for predicting primer-template mismatch behavior when using specific 5-nuclease assay master mixes. Our study provides novel insight into mismatch behavior and should allow for more optimized development of real-time PCR assays involving primer-template mismatches.

Adenovirus DNA positivity in nasopharyngeal aspirate preceding hematopoietic stem cell transplantation: a very strong risk factor for adenovirus DNAemia in pediatric patients.

Human adenovirus (HAdV)-positive nasopharyngeal aspirate preceding hematopoietic stem cell transplantation was prospectively analyzed in 62 patients. By multivariate Cox proportional hazard models, HAdV-positive nasopharyngeal aspirate was the only predictor for HAdV DNAemia after hematopoietic stem cell transplantation (P < .001). HAdV DNAemia was a predictor for alloreactive disease. Early detection and intervention might help to prevent HAdV disease after hematopoietic stem cell transplantation.

Sustained HBeAg and HBsAg loss after long-term follow-up of HBeAg-positive patients treated with peginterferon alpha-2b.

BACKGROUND & AIMS: The aim of this study was to evaluate the long-term sustainability of response in patients with hepatitis B e antigen (HBeAg)-positive chronic hepatitis B treated with pegylated interferon (PEG-IFN) alpha-2b alone or in combination with lamivudine. METHODS: All 266 patients enrolled in the HBV99-01 study were offered participation in a long-term follow-up (LTFU) study. Patients were treated with PEG-IFN alpha-2b (100 mug/wk) alone or in combination with lamivudine (100 mg/day) for 52 weeks. Initial response was defined as HBeAg negativity at 26 weeks posttreatment. For the LTFU study, patients had one additional visit after the initial study (mean interval, 3.0 +/- 0.8 years). RESULTS: Of 266 patients enrolled in the initial study, 172 (65%) participated in the LTFU study. At LTFU, HBeAg and hepatitis B surface antigen (HBsAg) negativity were observed in 37% and 11% of 172 patients, respectively. Sixty-four patients were classified as initial responders and 108 as nonresponders. Among the initial responders, sustained HBeAg negativity and HBsAg loss were observed in 81% and 30%, respectively. Significantly higher rates of HBeAg negativity were observed in genotype A-infected initial responders compared with those with genotype non-A (96% vs 76%; P = .06) as well as HBsAg loss (58% vs 11%; P < .001). CONCLUSIONS: HBeAg loss after treatment with PEG-IFN alpha-2b alone or in combination with lamivudine is sustained in the majority of patients and is associated with a high likelihood of HBsAg loss, particularly in genotype A-infected patients. Therefore, PEG-IFN alpha-2b remains an important treatment option in this era of nucleos(t)ide analogue therapy.

Comparison of the efficacy of early versus late viral proteins in vaccination against SIV.

The immune response against early regulatory proteins of simian- and human immunodeficiency virus (SIV, HIV) has been associated with a milder course of infection. Here, we directly compared vaccination with Tat/Rev versus Pol/Gag. Challenge infection with SIVmac32H (pJ5) suggested that vaccination with Tat/Rev induced cellular immune responses that enabled cynomolgus macaques to more efficiently control SIV replication than the vaccine-induced immune responses against Pol/Gag. Vaccination with Tat/Rev resulted in reduced plasma SIV loads compared with control (P=0.058) or Pol/Gag-vaccinated (P=0.089) animals, with undetectable plasma viral loads in two of the four Tat/Rev-vaccinated animals. Therefore, the results warrant further investigation of the early regulatory proteins and their potential for vaccination against HIV.