False-Reactive Fourth-Generation Human Immunodeficiency Virus Testing in Cancer Patients

BACKGROUND

The fourth-generation (4th-gen) human immunodeficiency virus (HIV)-1/2 antibody/antigen (Ab/Ag) combination immunoassay currently used for HIV screening offers greater sensitivity than previous assays, but false-reactive results occur in up to 20% of patients. Large-scale observations in cancer patients are lacking.

METHODS

We conducted a retrospective study of cancer patients seen at the University of Texas MD Anderson Cancer Center (March 2016-January 2023) who had reactive 4th-gen ARCHITECT HIV-1/2 Ab/Ag combination immunoassay results. We analyzed characteristics of patients with true-reactive and false-reactive results, defined based on Centers for Disease Control and Prevention criteria.

RESULTS

A total of 43 637 patients underwent 4th-gen HIV screening, and 293 had reactive 4th-gen HIV test results. Twenty-one patients were excluded because they did not have cancer. Among the remaining 272 patients, 78 (29%) had false-reactive results. None of these patients experienced delays in their cancer treatment, but 26% experienced mental distress. Multivariate logistic regression analysis identified 5 predictors of having false-reactive results: age >60 years (adjusted odds ratio [aOR], 6.983; P < .0001), female sex (aOR, 6.060; P < .0001), race/ethnicity (Black: aOR, 0.274; Hispanic: aOR, 0.236; P = .002), syphilis coinfection (aOR, 0.046; P = .038), and plant alkaloids therapy (aOR, 2.870; P = .013).

CONCLUSIONS

False-reactive 4th-gen HIV test results occur in almost one-third of cancer patients. Physicians should be aware of the high rates of false-reactive HIV screening results in this patient population. These findings may have implications for counseling regarding testing, especially among those at low risk for HIV infection.

A decontamination strategy for resolving SARS-CoV-2 amplicon contamination in a next-generation sequencing laboratory

Severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) amplicon contamination was discovered due to next-generation sequencing (NGS) reads mapping in the negative controls. Environmental screening was undertaken to determine the source of contamination, which was suspected to be evaporation during polymerase chain reaction (PCR) assays while using the coronavirus disease 2019 (COVID-19) ARTIC protocol. A decontamination strategy is hereby documented to assist laboratories that may experience similar amplicon contamination. Routine molecular laboratory environmental screening as a quality control is highly recommended.

Bayes Lines Tool (BLT): a SQL-script for analyzing diagnostic test results with an application to SARS-CoV-2-testing

The performance of diagnostic tests crucially depends on the disease prevalence, test sensitivity, and test specificity. However, these quantities are often not well known when tests are performed outside defined routine lab procedures which make the rating of the test results somewhat problematic. A current example is the mass testing taking place within the context of the world-wide SARS-CoV-2 crisis. Here, for the first time in history, laboratory test results have a dramatic impact on political decisions. Therefore, transparent, comprehensible, and reliable data is mandatory. It is in the nature of wet lab tests that their quality and outcome are influenced by multiple factors reducing their performance by handling procedures, underlying test protocols, and analytical reagents. These limitations in sensitivity and specificity have to be taken into account when calculating the real test results. As a resolution method, we have developed a Bayesian calculator, the Bayes Lines Tool (BLT), for analyzing disease prevalence, test sensitivity, test specificity, and, therefore, true positive, false positive, true negative, and false negative numbers from official test outcome reports. The calculator performs a simple SQL (Structured Query Language) query and can easily be implemented on any system supporting SQL. We provide an example of influenza test results from California, USA, as well as two examples of SARS-CoV-2 test results from official government reports from The Netherlands and Germany-Bavaria, to illustrate the possible parameter space of prevalence, sensitivity, and specificity consistent with the observed data. Finally, we discuss this tool’s multiple applications, including its putative importance for informing policy decisions.

Role of Chest Computed Tomography versus Real Time Reverse Transcription Polymerase Chain Reaction for Diagnosis of COVID-19: A Systematic Review and Meta-Analysis

Background

The current global pandemic of COVID-19 is considered a public health emergency. The diagnosis of COVID-19 depends on detection of the viral nucleic acid by real time reverse transcription polymerase chain reaction (RT-PCR). However, false-negative RT-PCR tests are reported and could hinder the control of the pandemic. Chest computed tomography could achieve a more reliable diagnosis and represent a complementary diagnostic tool.

Aim

To perform a meta-analysis and systematic review to find out the role of chest computed tomography versus RT-PCR for precise diagnosis of COVID-19 infection.

Methods

We searched three electronic databases (PubMed, ScienceDirect, and Scopus) from April 1 to April 20, 2020, to find out articles including the accuracy of chest computed tomography scan versus RT-PCR for diagnosis of SARS-CoV-2 infection. Observational studies, case series, and case reports were included.

Results

A total of 238 articles were retrieved from the search strategy. Following screening, 39 articles were chosen for full text assessment and finally 35 articles were included for qualitative and quantitative analysis. Chest computed tomography showed a wide range of sensitivity varied from 12%–100%.

Conclusion

Chest computed tomography is playing a key role for diagnosis and detection of COVID-19 infection. Computed tomography image findings may precede the initially positive RT-PCR assay.

Lessons from the COVID-19 Pandemic on the Use of Artificial Intelligence in Digital Radiology: The Submission of a Survey to Investigate the Opinion of Insiders

The development of artificial intelligence (AI) during the COVID-19 pandemic is there for all to see, and has undoubtedly mainly concerned the activities of digital radiology. Nevertheless, the strong perception in the research and clinical application environment is that AI in radiology is like a hammer in search of a nail. Notable developments and opportunities do not seem to be combined, now, in the time of the COVID-19 pandemic, with a stable, effective, and concrete use in clinical routine; the use of AI often seems limited to use in research applications. This study considers the future perceived integration of AI with digital radiology after the COVID-19 pandemic and proposes a methodology that, by means of a wide interaction of the involved actors, allows a positioning exercise for acceptance evaluation using a general purpose electronic survey. The methodology was tested on a first category of professionals, the medical radiology technicians (MRT), and allowed to (i) collect their impressions on the issue in a structured way, and (ii) collect their suggestions and their comments in order to create a specific tool for this professional figure to be used in scientific societies. This study is useful for the stakeholders in the field, and yielded several noteworthy observations, among them (iii) the perception of great development in thoracic radiography and CT, but a loss of opportunity in integration with non-radiological technologies; (iv) the belief that it is appropriate to invest in training and infrastructure dedicated to AI; and (v) the widespread idea that AI can become a strong complementary tool to human activity. From a general point of view, the study is a clear invitation to face the last yard of AI in digital radiology, a last yard that depends a lot on the opinion and the ability to accept these technologies by the operators of digital radiology.

High positive HIV serology results can still be false positive

The consequences of falsely reactive HIV test results can be significant, for patients and healthcare providers. This case describes a diagnostic investigation of a patient with pronounced discordant HIV serological results, to determine HIV status. The fourth generation serological screening assay (Roche COBAS Elecsys HIV combiPT) had high positive results but confirmatory testing was negative (Abbott HIV Ag/Ab Combo). Five separate samples over 13 days were tested using multiple fourth generation HIV immunoassays and molecular tests for HIV-1 and HIV-2. Potential causes of falsely reactive serological results were investigated. Samples were sent to the manufacturer for analysis.

The screening assay was positive on all samples with a very high signal to cut-off ratio (S/CO) of greater than 400. However, multiple serological and molecular assays did not detect HIV-1 or HIV-2 specific antibodies, antigen or nucleic acid. A recombinant immunochromatographic assay had faint reactivity to gp41 peptide and the manufacturer investigation reported cross-reactivity to one of the screening assay’s synthetic peptides. Possible causes of the false positive result include cross reactivity to other antigens, including prior schistosomiasis infection, or the patient’s previously excised ameloblastoma (a rare germ cell tumor of the jaw). This is a rare case of false high positive results on fourth-generation HIV serology testing due to high level non-specific reactivity to an isolated synthetic peptide component of the assay. It highlights the need for confirmatory testing even in settings with HIV high prevalence and awareness that false-positive serological results may have a high S/CO.

Challenges in Laboratory Diagnosis of the Novel Coronavirus SARS-CoV-2

The recent outbreak of the Coronavirus disease 2019 (COVID-19) has quickly spread worldwide since its discovery in Wuhan city, China in December 2019. A comprehensive strategy, including surveillance, diagnostics, research, clinical treatment, and development of vaccines, is urgently needed to win the battle against COVID-19. The past three unprecedented outbreaks of emerging human coronavirus infections at the beginning of the 21st century have highlighted the importance of readily available, accurate, and rapid diagnostic technologies to contain emerging and re-emerging pandemics. Real-time reverse transcriptase-polymerase chain reaction (rRT-PCR) based assays performed on respiratory specimens remain the gold standard for COVID-19 diagnostics. However, point-of-care technologies and serologic immunoassays are rapidly emerging with high sensitivity and specificity as well. Even though excellent techniques are available for the diagnosis of symptomatic patients with COVID-19 in well-equipped laboratories; critical gaps still remain in screening asymptomatic people who are in the incubation phase of the virus, as well as in the accurate determination of live viral shedding during convalescence to inform decisions for ending isolation. This review article aims to discuss the currently available laboratory methods and surveillance technologies available for the detection of COVID-19, their performance characteristics and highlight the gaps in current diagnostic capacity, and finally, propose potential solutions. We also summarize the specifications of the majority of the available commercial kits (PCR, EIA, and POC) for laboratory diagnosis of COVID-19.

Potential preanalytical and analytical vulnerabilities in the laboratory diagnosis of coronavirus disease 2019 (COVID-19)

A novel zoonotic coronavirus outbreak is spreading all over the world. This pandemic disease has now been defined as novel coronavirus disease 2019 (COVID-19), and is sustained by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). As the current gold standard for the etiological diagnosis of SARS-CoV-2 infection is (real time) reverse transcription polymerase chain reaction (rRT-PCR) on respiratory tract specimens, the diagnostic accuracy of this technique shall be considered a foremost prerequisite. Overall, potential RT-PCR vulnerabilities include general preanalytical issues such as identification problems, inadequate procedures for collection, handling, transport and storage of the swabs, collection of inappropriate or inadequate material (for quality or volume), presence of interfering substances, manual errors, as well as specific aspects such as sample contamination and testing patients receiving antiretroviral therapy. Some analytical problems may also contribute to jeopardize the diagnostic accuracy, including testing outside the diagnostic window, active viral recombination, use of inadequately validated assays, insufficient harmonization, instrument malfunctioning, along with other specific technical issues. Some practical indications can hence be identified for minimizing the risk of diagnostic errors, encompassing the improvement of diagnostic accuracy by combining clinical evidence with results of chest computed tomography (CT) and RT-PCR, interpretation of RT-PCR results according to epidemiologic, clinical and radiological factors, recollection and testing of upper (or lower) respiratory specimens in patients with negative RT-PCR test results and high suspicion or probability of infection, dissemination of clear instructions for specimen (especially swab) collection, management and storage, together with refinement of molecular target(s) and thorough compliance with analytical procedures, including quality assurance.