HCV false positive immunoassays in patients with LVAD: A potential trap!

Clinical performance of the MAGLUMI Anti-HCV (CLIA) Test for detection of hepatitis C virus antibodies

BACKGROUND

Hepatitis C virus (HCV) infection screening and diagnosis are critical to control the hepatitis C epidemic. Testing for anti-HCV antibodies (Ab) in blood samples is the first step to screen people who have been infected with the virus.

OBJECTIVES

To evaluate the performance of the MAGLUMI Anti-HCV (CLIA) Test for detection of HCV antibodies.

STUDY DESIGN

To assess the diagnostic specificity, serum samples from 5053 unselected donors and 205 blood specimens from hospitalized patients were collected. To evaluate the diagnostic sensitivity, 400 positive HCV Ab samples were collected and 30 seroconversion panels were tested. All samples that met the test criteria were tested with the MAGLUMI Anti-HCV (CLIA) Test according to manufacturer's instruction. Results of the MAGLUMI Anti-HCV (CLIA) Test were compared with the Abbott ARCHITECT anti-HCV reference test.

RESULTS

The specificity of the MAGLUMI Anti-HCV (CLIA) Test was 99.75% and 100.00% in blood donor and hospitalized patient samples, respectively. The sensitivity of the Test in HCV Ab positive samples was 100.00%. Seroconversion sensitivity was comparable between the MAGLUMI Anti-HCV (CLIA) Test and the reference assay.

CONCLUSIONS

The performance of the MAGLUMI Anti-HCV (CLIA) Test makes it suited for HCV infection diagnosis.

Updating the Signal-to-cutoff Level to Reduce Anti-hepatitis C Virus False Positivity

Background: Anti-hepatitis C virus (anti-HCV) is the only screening test being used in the diagnosis of hepatitis C. In this study, we examined anti-HCV positivity rates in our hospital. Objectives: The aim of administering the anti-HCV test was to distinguish patients with hepatitis C infection from false positivity in patients with reactive results. Methods: The anti-HCV tests were performed at Fatih Sultan Mehmet Training and Research Hospital in Istanbul, Turkey, between January 1, 2015 and December 31, 2019. The patients were evaluated retrospectively in terms of age, gender, anti-HCV titer, the clinic for which the examination was requested, the reason for the examination, and the history of hepatitis C. Results: In this study, 511 patients who had two negative polymerase chain reaction (PCR) results were evaluated as false positive cases and enrolled. The cut-off value was found to be 7.5 IU/ml, with the highest sensitivity of 94.4% and specificity of 94.5% (area under the curve [AUC]: 0.982). The lowest anti-HCV titer (5.2) was from patients without acute hepatitis, who were HCV-RNA positive and diagnosed with chronic hepatitis C. Conclusions: It may be more appropriate to report anti-HCV cut-off value of 0 - 5 as negative, 5 - 7.5 as borderline, and > 7.5 as positive. Working with a more acceptable cut-off level with a greater number of tests can help identify patients with asymptomatic HCV infection. Also, it can possibly reduce the cost due to a decrease in the number of PCR tests administered.

The role of a two-assay serological testing strategy for anti-HCV screening in low-prevalence populations

HCV screening depends mainly on a one-assay anti-HCV testing strategy that is subject to an increased false-positive rate in low-prevalence populations. In this study, a two-assay anti-HCV testing strategy was applied to screen HCV infection in two groups, labelled group one (76,442 people) and group two (18,415 people), using Elecsys electrochemiluminescence (ECL) and an Architect chemiluminescent microparticle immunoassay (CMIA), respectively. Each anti-HCV-reactive serum was retested with the other assay. A recombinant immunoblot assay (RIBA) and HCV RNA testing were performed to confirm anti-HCV positivity or active HCV infection. In group one, 516 specimens were reactive in the ECL screening, of which CMIA retesting showed that 363 (70.3%) were anti-HCV reactive (327 positive, 30 indeterminate, 6 negative by RIBA; 191 HCV RNA positive), but 153 (29.7%) were not anti-HCV reactive (4 positive, 29 indeterminate, 120 negative by RIBA; none HCV RNA positive). The two-assay strategy significantly improved the positive predictive value (PPV, 64.1% & 90.1%, P < 0.05). In group two, 87 serum specimens were reactive according to CMIA screening. ECL showed that 56 (70.3%) were anti-HCV reactive (47 positive, 8 indeterminate, 1 negative by RIBA; 29 HCV RNA positive) and 31 (29.7%) were anti-HCV non-reactive (25 negative, 5 indeterminate, 1 positive by RIBA; none HCV RNA positive). Again, the PPV was significantly increased (55.2% & 83.9%, P < 0.05). Compared with a one-assay testing strategy, the two-assay testing strategy may significantly reduce false positives in anti-HCV testing and identify inactive HCV infection in low-seroprevalence populations.

Progress in evaluating the status of hepatitis C infection based on the functional changes of hepatic stellate cells (Review)

Hepatitis C virus (HCV) infection is a global public health problem. Cirrhosis and hepatocellular carcinoma are the main causes of death in patients with chronic hepatitis C (CHC) infection. Liver fibrosis is an important cause of cirrhosis and end‑stage liver disease after CHC infection. Along with the course of infection, liver fibrosis exhibits a progressive exacerbation. Hepatic stellate cells (HSCs) are involved in both physiological and pathological processes of the liver. During the chronic liver injury process, the activated HSCs transform into myofibroblasts, which are important cells in the development of liver fibrosis. At present, HCV infection still lacks specific markers for the accurate detection of the disease condition and progression. Therefore, the present review focused on HSCs, which are closely related to HCV‑infected liver fibrosis, and analyzed the changes in the HSCs, including their surface‑specific markers, cytokine production, activation, cell function and morphological structure. The present review aimed to propose novel diagnostic markers, at both the cellular and molecular level, which would be of great significance for the timely diagnosis of the disease. According to this aim, the characteristic changes of HSCs during HCV infection were reviewed in the present article.

CDC Recommendations for Hepatitis C Screening Among Adults - United States, 2020

Hepatitis C virus (HCV) infection is a major source of morbidity and mortality in the United States. HCV is transmitted primarily through parenteral exposures to infectious blood or body fluids that contain blood, most commonly through injection drug use. No vaccine against hepatitis C exists and no effective pre- or postexposure prophylaxis is available. More than half of persons who become infected with HCV will develop chronic infection. Direct-acting antiviral treatment can result in a virologic cure in most persons with 8-12 weeks of all-oral medication regimens. This report augments (i.e., updates and summarizes) previously published recommendations from CDC regarding testing for HCV infection in the United States (Smith BD, Morgan RL, Beckett GA, et al. Recommendations for the identification of chronic hepatitis C virus infection among persons born during 1945-1965. MMWR Recomm Rec 2012;61[No. RR-4]). CDC is augmenting previous guidance with two new recommendations: 1) hepatitis C screening at least once in a lifetime for all adults aged ≥18 years, except in settings where the prevalence of HCV infection is <0.1% and 2) hepatitis C screening for all pregnant women during each pregnancy, except in settings where the prevalence of HCV infection is <0.1%. The recommendation for HCV testing that remains unchanged is regardless of age or setting prevalence, all persons with risk factors should be tested for hepatitis C, with periodic testing while risk factors persist. Any person who requests hepatitis C testing should receive it, regardless of disclosure of risk, because many persons might be reluctant to disclose stigmatizing risks.

Transplantation of viral-positive hepatitis C-positive kidneys into uninfected recipients offers an opportunity to increase organ access

The advent of direct-acting antivirals (DAAs) has provided the impetus to transplant kidneys from hepatitis C virus-positive donors into uninfected recipients (D+/R-). Thirty D+/R- patients received DAA treatment. Sustained virologic response (SVR12) was defined as an undetectable viral load in 12 weeks after treatment. An age-matched cohort of uninfected donor and recipient pairs (D-/R-) transplanted during same time period was used for comparison. The median day of viral detection was postoperative day (POD) 2. The detection of viremia in D+/R- patients was 100%. The initial median viral load was 531 copies/μL (range: 10-1 × 10⁸ copies/μL) with a median peak viral load of 3.4 × 10⁵ copies/μL (range: 804-1.0 × 10⁸ copies/μL). DAAs were initiated on median POD 9 (range: 5-41 days). All 30 patients had confirmed SVR12. During a median follow-up of 10 months, patient and graft survival was 100%, and acute rejection was 6.6% with no major adverse events related to DAA treatment. Delayed graft function was significantly decreased in D+/R- patients as compared to the age-matched cohort (27% vs 60%; P = .01). D+/R- transplantation offers patients an alternative strategy to increase access.

Seroreversion of positive anti-hepatitis C virus antibodies in left ventricular assist device recipients: Now you see them, now you don't

The clinical significance of positive anti-hepatitis C virus (anti-HCV) antibody tests in recipients of left ventricular assist devices remains unclear. In light of emerging evidence suggesting the possibility of persistent low-level HCV infection in patients with positive anti-HCV antibody test but negative HCV ribonucleic acid, it is very important to distinguish the truly false positive HCV antibodies, in recipients of continuous flow left ventricular assist devices, from those suggestive of a prior clinically resolved infection or one where a low-level viremia may have persisted. We conducted a retrospective analysis of left ventricular assist device recipients at our institution. While the total incidence of positive HCV antibody with concomitantly negative HCV ribonucleic acid test (19.2%) was in keeping with the incidences reported in prior cross-sectional studies, we longitudinally followed our patients and observed a 100% seroreversion. Seroreversion, which has not been reported in other studies, occurred either during continued left ventricular assist device support (10 out of 26) or after heart transplant (7 out of 26). Hundred percent seroreversion strongly suggested that the anti-HCV antibodies were truly false positive.

The American Society of Transplantation Consensus Conference on the Use of Hepatitis C Viremic Donors in Solid Organ Transplantation

The availability of direct-acting antiviral agents for the treatment of hepatitis C virus (HCV) infection has resulted in a profound shift in the approach to the management of this infection. These changes have affected the practice of solid organ transplantation by altering the framework by which patients with end-stage organ disease are managed and receive organ transplants. The high level of safety and efficacy of these medications in patients with chronic HCV infection provides the opportunity to explore their use in the setting of transplanting organs from HCV-viremic patients into non-HCV-viremic recipients. Because these organs are frequently discarded and typically come from younger donors, this approach has the potential to save lives on the solid organ transplant waitlist. Therefore, an urgent need exists for prospective research protocols that study the risk versus benefit of using organs for hepatitis C-infected donors. In response to this rapidly changing practice and the need for scientific study and consensus, the American Society of Transplantation convened a meeting of experts to review current data and develop the framework for the study of using HCV viremic organs in solid organ transplantation.

Dielectrophoresis for Biomedical Sciences Applications: A Review

Dielectrophoresis (DEP) is a label-free, accurate, fast, low-cost diagnostic technique that uses the principles of polarization and the motion of bioparticles in applied electric fields. This technique has been proven to be beneficial in various fields, including environmental research, polymer research, biosensors, microfluidics, medicine and diagnostics. Biomedical science research is one of the major research areas that could potentially benefit from DEP technology for diverse applications. Nevertheless, many medical science research investigations have yet to benefit from the possibilities offered by DEP. This paper critically reviews the fundamentals, recent progress, current challenges, future directions and potential applications of research investigations in the medical sciences utilizing DEP technique. This review will also act as a guide and reference for medical researchers and scientists to explore and utilize the DEP technique in their research fields.

False positive hepatitis C antibody test results in left ventricular assist device recipients: increased risk with age and transfusions

Left ventricular assist devices (LVADs) have been successfully used in patients with heart failure. However, LVADs may trigger immune activation, leading to higher frequencies of autoantibodies. We describe the clinical, epidemiological, and laboratory characteristics of LVAD recipients with false positive hepatitis C (FPHC) serology among 39 consecutive adult LVAD recipients who bridged to heart transplantation from January 2007 to January 2013 at Montefiore Medical Center. FPHC patients were identified as those with post-LVAD positive hepatitis C ELISA antibody tests and negative confirmatory testing with hepatitis C RNA PCR and/or radioimmunoblot assay. Ten (26%) patients previously seronegative for hepatitis C were found to have FPHC after device placement. Of the 39 patients, 32 had HeartMate II devices. The mean age at LVAD placement was 55 years. FPHC correlated with older age at the time of LVAD implantation and with receipt of packed red blood cell transfusions, but not with gender, fresh frozen plasma transfusions, panel reactive antibodies, globulin fraction, rheumatoid factor, or anticardiolipin antibodies. Clinicians should be aware of this increased risk of FPHC in older LVAD patients and those more heavily transfused in order to avoid unnecessary apprehension and possible delay in transplantation. Further studies should be done to evaluate the possible relationship between transfused blood products and immunomodulation.