Journal of Clinical Virology最新文献

Background

Developing countries experience limited access to HCV laboratory tests for different reasons. Providing near to real–time HCV testing and results especially to at–risk populations including those in rural settings for timely initiation to treatment is key. Within a rural Myanmar setting, we compared HCV diagnostic detection and quantification of the GeneXpert, and Advanced Biological Laboratories UltraGene–HCV assays against the gold standard and reference method Roche real–time HCV in Myanmar.

Methods

Blood samples from 158 high–risk individuals were assessed using three different methods at baseline. Results were checked for normality and log transformed. Log differences and bias between methods were calculated and correlated. Pearson's correlation coefficient was used to determine the association of HCV viral loads across all methods. The level of agreement with the standard method (Roche real time HCV) was assessed using Bland–Altman analyses.

Results

There was a strong positive correlation coefficient between all three methods with GeneXpert and Roche having the strongest, r = 0.96, (p<0.001). Compared to Roche, ABL (mean difference, 95 % limits of agreement; -0.063 and -1.4 to 1.3 Log10IU/mL) and GeneXpert (mean difference, 95 % limits of agreement; -0.28 and -0.7 to 1.8 Log10IU/mL) showed a good level of agreement with the GeneXpert being slightly superior.

Conclusion

We demonstrate the excellent performance and no-inferiority, in terms of levels of agreements of both GeneXpert and ABL compared to the Roche platform and supporting the use of the POC assays as alternative a cost-effective methods in HCV detection and diagnosis in developing and low resource settings countries.

Background

The QuantiFERONCMV (QF-CMV) assay is an interferon-gamma release assay (IGRA) used to monitor CMV-specific cell-mediated immunity (CMV-CMI) by ELISA in transplant patients. However, a chemiluminescent immunoassay (CLIA) has been developed to quantify IFNG in the QuantiFERON-Tuberculosis (TB) to detect latent TB infection.

Objectives

The aim of this work is to compare the results of QF-CMV by ELISA with those obtained by CLIA in an automated Liaison XL analyzer using the QuantiFERON-TB Gold Plus reagents.

Study Design

The QF-CMV assay had been performed by ELISA in kidney and lung transplant patients between July 2019-April 2023 at the IMIBIC/Reina Sofía Hospital (Cordoba, Spain). The remaining QF-CMV supernatants had been preserved at -80 ºC from then. Now, the IFNG levels in the same samples were determined by CLIA.

Results

One hundred and three QF-CMV supernatants from kidney (n = 50) and lung (n = 53) transplant patients were selected. An agreement of 87.4 % (kappa coefficient 0.788) between CLIA and ELISA was observed. Thirteen (12.6 %) discrepant results were detected. Some Indeterminate results by ELISA converted to Non-reactive by CLIA (0.53–0.92 IU/mL for Mitogen-Nil values). Likewise, borderline Non-reactive results by ELISA were above the 0.2 IU/mL cut-off by CLIA and then were Reactive (0.21–0.31 for CMV-Nil values).

Conclusion

CLIA shows substantial concordance with ELISA and acceptable discrepancies. The possible higher sensitivity of CLIA returns a higher number of Reactive results, which entails potential clinical consequences. Therefore, a new threshold to confer protection against CMV infection after transplantation needs to be defined.

Background

Hepatitis Delta virus (HDV) infection is a major cause of liver-related morbidity and mortality in patients infected with HBV, with a global HDV prevalence uncertain. In France, 2 to 5 % of HBs antigen (HBsAg) carriers present anti-HDV antibodies (anti-HDV). The EASL recommends testing for anti-HDV in all HBsAg-positive patients. Since January 2022, we have systematically carried out anti-HDV serology when a positive HBsAg is discovered (new HBsAg carriers).

Objectives

We evaluated the benefit of anti-HDV reflex testing after one year of practice by comparing anti-HDV and HBsAg serology data over the last six years, among the new HBsAg carriers and all the HBsAg carriers.

Study design

HBsAg and anti-HDV were screened using the Abbott Architect HBsAg quanti kit and the DIA.PRO HDVAb kit. Serological, demographic, virological, and clinical data were analyzed.

Results

Implementing anti-HDV reflex testing leads to more than a 2-fold increase in diagnoses of HDV infection among all HBsAg carriers. If the anti-HDV positive rate remains stable among the new HBsAg carriers, a significant increase in the anti-HDV positive rate from 6.8 % to 10.3 % was observed considering all HBsAg carriers. Interestingly, the discovery of anti-HDV carriage increased from 3.9 % to 6.5 % in 2022, allowing earlier identification of HBV-HDV-infected patients and a fast referral to hepatologists for adequate clinical management and, in some cases, the introduction of bulevirtide-based therapy.

Conclusions

Our preliminary results at one year seem promising and evaluating the cost-effectiveness of reflex tests in real life with feedback would be helpful.

Background

Human papillomavirus (HPV) testing on self-samples is a valid tool for cervical cancer screening. HPV self-sample workflows need to be clinically validated to ensure safe use in screening.

Objective

This study evaluated the fully automated NeuMoDx HPV Assay self-sample workflow that is compiled of the NeuMoDx HPV assay and the NeuMoDx 96/288 Molecular Systems, for clinical performance and reproducibility on Evalyn Brush-collected self-samples.

Methods

The clinical performance of the NeuMoDx HPV Assay self-sample workflow for cervical intraepithelial neoplasia grade 2 or worse (CIN2+) and CIN3+ was evaluated on 987 self-samples obtained from women attending national organized HPV-based cervical cancer screening by a noninferiority analysis relative to reference workflows using either HPV-Risk Assay or high-risk HPV GP5+/6+-PCR. Intra- and inter-laboratory reproducibility of the NeuMoDx HPV Assay self-sample workflow using both NeuMoDx 96 and 288 Molecular Systems was assessed on 520 self-samples in three laboratories.

Results

The clinical sensitivity and specificity of the NeuMoDx HPV Assay self-sample workflow for the detection of CIN2+ and CIN3+ were found to be non-inferior to the reference workflows using either HPV-Risk Assay or high-risk HPV GP5+/6+-PCR, with all p-values <0.034. The NeuMoDx HPV Assay self-sample workflow exhibited an intra-laboratory reproducibility of 94.4 % (95 %CI:92.5–96.1 %) with kappa value 0.86 (95 %CI:0.81–0.91). Inter-laboratory agreement was high (all ≥93.4 % and all kappa values ≥0.83).

Conclusions

The NeuMoDx HPV Assay self-sample workflow demonstrated high clinical accuracy for CIN2+/3+ and high reproducibility. The NeuMoDx HPV Assay self-sample workflow can be considered suitable for cervical cancer screening purposes.

Background

Varicella zoster virus (VZV) is among the leading pathogens causing meningitis and encephalitis. While VZV-PCR-positive CSF is considered a gold-standard for diagnosis, it is not-uncommon to detect VZV-DNA in CSF of patients with other acute or chronic illness. Our goal was to determine the clinical relevance of VZV-PCR-positive CSF when investigating patients with neurological symptoms.

Methods

In this retrospective cohort from the largest hospital in Israel, we collected demographic, clinical and laboratory data of patients with VZV-PCR-positive CSF, analyzing the significance of various parameters.

Results

During a 5-years study, 125 patient-unique VZV-PCR-positive CSFs were recorded, in which only 9 alternative diagnoses were noted. The commonest symptoms were headache (N = 104, 83 %) and rash (N = 96, 76 %). PCR-cycle-threshold (Ct), a surrogate of viral burden, did not significantly vary across the clinical manifestations; however, patients with rash and Ct<35 were prone to develop stroke in the following year (N = 6, 7 %). Empiric nucleoside-analogue treatment was not associated with a better outcome compared to treatment administered upon a positive-PCR result.

Discussion

Our findings suggest that in patients with neurological symptoms, detection of VZV-DNA in CSF renders VZV the probable culprit. Nevertheless, a systematic evaluation of treatment and follow-up algorithms of patients with suspected or proved VZV meningitis and encephalitis is needed. The benefits of a prompt treatment should be weighed against the potential complications of nucleoside-analogue. Conversely, the propensity for stroke in patients with higher viral-burden, necessitates further studies assessing VZV causal role, directing additional workup, treatment and monitoring policy.

Background: Human Adenoviruses are a common cause of disease and can cause significant morbidity and mortality in immunocompromised patients. Nosocomial transmission events can occur with whole genome sequencing playing a crucial role. This study evaluates the performance of a custom designed SureSelect^XT target enrichment assay based on 14 adenovirus genomes for sequencing direct from clinical samples.

Methods: Modifications were made to the SureSelect^XT low input protocol to enhance performance for viral targets. Consensus sequences were generated using an in-house designed three stage bioinformatics pipeline. We assessed, percentage of on target reads, average depth of coverage and percentage genome coverage to determine assay performance across a range of sample matrices.

Results: Whole genome sequences were successfully generated for 91.6 % of samples assessed. Adenovirus DNA concentration was a good indicator of enrichment success. Highly specific enrichment was observed with only 6 % of samples showing < 50 % on target reads. Respiratory and faecal samples performed well where bloods showed higher levels of non-specific enrichment likely confounded by low adenovirus DNA concentrations. Protocol performance did not appear impacted by Adenovirus type or species.

Conclusion: Overall performance of this modified SureSelect^XT protocol appears in line with previously published works although there are some confounding factors requiring further investigation. The use of a small RNA bait set has the potential to reduce associated costs which can be prohibitive.

Background

Tackling HIV drug resistance is one of major challenges for ending AIDS epidemic, but the elevated expense of cutting-edge genomics hampers the advancement of HIV genotype testing for clinical care.

Methods

We developed a HIV genotype testing pipeline that centers on a cost-efficient portable Nanopore sequencer. Accuracy verification was conducted through comparison with parallel data obtained via fixed-site Pacbio sequencing. Our complete pol-gene sequencing strategy coupled with portable high-throughput sequencing was applied to identify drug resistance mutations across 58 samples sourced from the ART-treated Los Angeles General Medical Center Rand Schrader Clinic (LARSC) cohort (7 samples from 7 individuals) and the ART-naïve Center for HIV/AIDS Vaccine Immunology (CHAVI) cohort (51 samples from 38 individuals).

Results

A total of 472 HIV consensus sequences, each tagged with a unique molecular identifier, were produced from over 1.4 million bases acquired through portable Nanopore sequencing, which matched those obtained independently via Pacbio sequencing. With this desirable accuracy, we first documented the linkage of multidrug cross-resistance mutations across Integrase Strand Transfer inhibitors (INSTIs) and Non-Nucleoside Reverse Transcriptase Inhibitors (NNRTIs) from an individual failing a second-generation INSTI regimen. By producing more than 500 full-length HIV pol gene sequences in a single portable sequencing run, we detected Protease Inhibitor (PI), Nucleoside Reverse Transcriptase Inhibitor (NRTI), NNRTI and INSTI resistance mutations. All drug resistance mutations identified through portable sequencing were cross-validated using fixed-site Pacbio sequencing.

Conclusions

Our accurate and affordable HIV drug resistance testing solution is adaptable for both individual patient care and large-scale surveillance initiatives.

Background

Reliable and fast detection and quantification of human cytomegalovirus (CMV) DNA in various diagnostic specimens is essential for care of immunocompromised or congenitally infected individuals.

Objectives

To evaluate the analytical and clinical performance of the Panther Aptima® CMV (Hologic) quantitative real-time transcription mediated amplification (TMA) assay.

Study design

Performance of the TMA assay run on the Hologic Panther Fusion was analysed for 32 proficiency testing samples and 21 quantitative reproducibility panel samples; additionally, we compared results of TMA assay and routine quantitative real-time PCR assays ("PCR-A"= Biomérieux CMV R-gene® or "PCR-B"= Laboratory-developed CMV-PCR) in 518 diagnostic specimens (254 plasma, 120 EDTA whole blood, 43 urine, 45 amniotic fluid and 56 breast milk) at two university hospital laboratories.

Results

All proficiency panel samples were correctly identified and quantified by the TMA assay; replicate testing of the reproducibility panel samples showed good reproducibility within and between the two laboratories. Sensitivity in plasma and WB was higher for the TMA assay detecting low-level CMV-DNAemia in samples tested negative by routine PCR. Quantitative CMV-DNAemia values correlated well between TMA and real-time PCR. Similarly, urine, AF and BM specimens showed a high rate of concordant results (91%, 98% and 98%, respectively) among TMA and PCR with good correlation of quantitative values.

Conclusion

The performance of the Aptima® CMV TMA assay for viral blood load testing compared well to established real-time PCRs. In addition, it can be useful for diagnostics in urine, amniotic fluid and breast milk specimens.

Human papillomavirus (HPV)-based screening offers better protection against cervical cancer compared to cytology, but HPV screening assays must adhere to validation requirements of the international guidelines to ensure optimal performance. Allplex HPV HR Detection (Allplex) assay, launched in the late 2022, is a fully automated real-time PCR-based assay utilizing innovative technology that enables quantification and concurrent distinction of 14 high-risk HPV genotypes (HPV16,18,31,33,35,39,45,51,52,56,58,59,66 and 68). We assessed the validity of the Allplex for cervical cancer screening purposes, via comparison to a clinically validated comparator assay (Hybrid Capture 2; HC2), and through assessment of intra-laboratory reproducibility and inter-laboratory agreement. A clinical validation panel comprised of 973 residual ThinPrep samples was obtained from women aged 30-64 years participating in the organized Slovenian screening program, of these 863 were from women undergoing their regular screening visit after a previous negative screen test while 110 were from women with underlying cervical intraepithelial neoplasia grade 2 or worse (CIN2+) lesions. The Allplex's relative clinical sensitivity for detection of CIN2+ and CIN3+ were 1.01 (95%CI;0.98-1.04) and 0.98 (95%CI;0.95-1.02), compared to that of HC2. At recommended thresholds of ≥98% and ≥90%, the Allplex's clinical sensitivity and specificity (p=0.0004 and p=0.02, respectively) were non-inferior to HC2. High intra-laboratory reproducibility and inter-laboratory agreement, both overall (98.1% and 97.9%, respectively) and at genotype level (>98.7%) was observed. In addition, analytical genotype-specific performance of Allplex was compared to that of its predecessor Anyplex HPV HR; high overall agreement was observed (96.3%; kappa value 0.88), with some variations in performance. In conclusion, Allplex met all validation criteria described in the international guidelines on sensitivity, specificity and laboratory reproducibility and can be considered clinically validated for primary cervical cancer screening.

Background

Cytomegalovirus (CMV) can cause a wide panel of ocular infections. The involvement of CMV as a cause of anterior uveitis in the immunocompetent patient is recent and remains poorly understood.

Objective

To investigate the presence of CMV in anterior uveal tissues of immunocompetent corneal donors.

Study Design

We collected aqueous humor, iris, and ciliary body from both eyes of 25 donors died at the Limoges University Hospital between January 2020 and July 2021. CMV serology was determined for all patients from post-mortem blood sample. Ocular tissues were split in 2 fragments for qPCR and 2 for histological analysis. CMV genomes copies were quantified by Multiplex qPCR after DNA extraction.

Results

16 of 25 patients (64%) displayed positive CMV serology, with a median age of 67 years. Viremia was positive in 3 of 16 (19%) CMV-positive patients. No CMV DNA copies were found from the aqueous humor samples. CMV DNA was detected in iris and ciliary body of 28 of 32 eyes of seropositive donors, and 5 of 18 eyes of seronegative donors. The median viral copy number [IQR] was 2.41 × 10² [8.91 × 10¹ - 1.01 × 10³] copies/1 × 10⁶ cells in the CMV-positive group and 0.00 [0.00 - 3.54 × 10²] copies/1 × 10⁶ cells in the CMV-negative group (p<0.001). Histology and immunohistochemistry did not reveal any CMV lesions from any sample.

Conclusion

CMV DNA was found in iris and ciliary body of immunocompetent seropositive patients, but also, although less frequently, from seronegative donors. These results highlight mechanisms of infection, latency and reactivation of CMV in ocular tissues.