Diagnostic concordance of pathological methods and reports of hematopathologists compared to local nonspecialized pathologists in the diagnosis of lymphoma in Mexico.

OBJECTIVES: To assess the concordance between lymphoma diagnoses made via tissue biopsy by local pathologists and also to assess the after review of these specimens by more specialized hematopathologists. METHODS: A prospective, non-interventional and multicenter study was conducted at seven sites in Mexico from January 2017 to October 2017. Eligible biopsies were sampled from patients with a previous diagnosis of lymphoma on lymph node biopsy or a diagnosis of extranodal lymphoma, with adequate amount and tissue preservation for the review analysis. The biopsy tissues reviewed by local pathologists were also reviewed by hematopathologists participating in the study. The concordance in diagnosis results was classified into three categories: diagnostic agreement, minor discrepancy and major discrepancy. RESULTS: Out of 111 samples received, 105 samples met the eligibility criteria and were included for full analysis. The median patient age (range) was 54 (16-94) years. A diagnostic agreement was observed in 23 (21.9%) biopsies, minor discrepancies were observed in 32 (30.5%) biopsies and major discrepancies were observed in 50 (47.6%) biopsies. Diagnostic concordance varied across the seven study sites; the rate of major discrepancies ranged from 0% to 100% and the rate of diagnostic agreement ranged from 0% to 81.8%. Out of the 105 reviewed biopsies, a total of 89 cases were diagnosed as lymphoma by hematopathologists. CONCLUSIONS: This study showed that major discrepancies were observed following the review by hematopathologists compared with that of the local pathologist's initial diagnosis in nearly one-half cases. In addition, there was a wide variation in the percentage of diagnostic agreements and discrepancies among different study sites.

Standardisation of pathogenicity classification for somatic alterations in solid tumours and haematologic malignancies.

BACKGROUND: The difficulty in interpreting somatic alterations is correlated with the increase in sequencing panel size. To correctly guide the clinical management of patients with cancer, there needs to be accurate classification of pathogenicity followed by actionability assessment. Here, we describe a specific detailed workflow for the classification of the pathogenicity of somatic variants in cancer into five categories: benign, likely benign, unknown significance, likely pathogenic and pathogenic. METHODS: Classification is obtained by combining a set of eight relevant criteria in favour of either a pathogenic or a benign effect (pathogenic stand-alone, pathogenic very strong, pathogenic strong, pathogenic moderate, pathogenic supporting, benign supporting, benign strong and benign stand-alone). RESULTS: Our guide is concordant with the ACMG/AMP 2015 guidelines for germline variants. Interpretation of somatic variants requires considering specific criteria, such as the disease and therapeutic context, co-occurring genomic events in the tumour when available and the use of cancer-specific variant databases. In addition, the gene role in tumorigenesis (oncogene or tumour suppressor gene) also needs to be taken into consideration. CONCLUSION: Our classification could contribute to homogenize best practices on somatic variant pathogenicity interpretation and improve interpretation consistency both within and between laboratories.

Guidelines for cellular and molecular pathology content in clinical trial protocols: the SPIRIT-Path extension.

The 2013 SPIRIT (Standard Protocol Items: Recommendations for Interventional Trials) Statement provides evidence-based recommendations for the minimum content to be included in a clinical trial protocol. Assessment of biospecimens is often required for trial eligibility or as part of an outcome evaluation, and precision molecular approaches are increasingly used in trial design. However, cellular and molecular pathology practices within trials have not been codified or formalised. We developed international consensus reporting guidelines for cellular and molecular pathology content in clinical trial protocols (the SPIRIT-Path extension) using an international Delphi process, which assesses candidate items generated from a previous systematic review, followed by an expert consensus meeting. 74 individuals from five continents responded, including clinicians, statisticians, laboratory scientists, patient advocates, funders, industry representatives, journal editors, and regulators. The SPIRIT-Path guidelines recommend 14 additional items (seven extensions to the SPIRIT checklist and seven elaborations) that should be addressed in trial protocols containing pathology content, alongside the SPIRIT 2013 Statement items. SPIRIT-Path recommends that protocols should document the individuals, processes, and standards for all cellular and molecular pathology components of the trial, including all stages of the specimen pathway and any digital pathology methods, with specific consideration of the value of trial data and biological tissues for additional translational studies.

Recommendations for cellular and molecular pathology input into clinical trials: a systematic review and meta-aggregation.

The SPIRIT (Standard Protocol Items: Recommendations for Interventional Trials) 2013 Statement was developed to provide guidance for inclusion of key methodological components in clinical trial protocols. However, these standards do not include guidance specific to pathology input in clinical trials. This systematic review aims to synthesise existing recommendations specific to pathology practice in clinical trials for implementation in trial protocol design. Articles were identified from database searches and deemed eligible for inclusion if they contained: (1) guidance and/or a checklist, which was (2) pathology-related, with (3) content relevant to clinical trial protocols or could influence a clinical trial protocol design from a pathology perspective and (4) were published in 1996 or later. The quality of individual papers was assessed using the AGREE-GRS (Appraisal of Guidelines for REsearch & Evaluation - Global Rating Scale) tool, and the confidence in cumulative evidence was evaluated using the GRADE-CERQual (Grading of Recommendations Assessment, Development and Evaluation-Confidence in Evidence from Reviews of Qualitative research) approach. Extracted recommendations were synthesised using the best fit framework method, which includes thematic analysis followed by a meta-aggregative approach to synthesis within the framework. Of the 10 184 records screened and 199 full-text articles reviewed, only 40 guidance resources met the eligibility criteria for inclusion. Recommendations extracted from 22 guidance documents were generalisable enough for data synthesis. Seven recommendation statements were synthesised as follows: (1) multidisciplinary collaboration in trial design with early involvement of pathologists, particularly with respect to the use of biospecimens and associated biomarker/analytical assays and in the evaluation of pathology-related parameters; (2) funding and training for personnel undertaking trial work; (3) selection of an accredited laboratory with suitable facilities to undertake scheduled work; (4) quality assurance of pathology-related parameters; (5) transparent reporting of pathology-related parameters; (6) policies regarding informatics and tracking biospecimens across trial sites; and (7) informed consent for specimen collection and retention for future research.

Incidents in Molecular Pathology: Frequency and Causes During Routine Testing.

CONTEXT.­: Errors in laboratory medicine could compromise patient safety. Good laboratory practice includes identifying and managing nonconformities in the total test process. Varying error percentages have been described in other fields but are lacking for molecular oncology. OBJECTIVES.­: To gain insight into incident causes and frequency in the total test process from 8 European institutes routinely performing biomarker tests in non-small cell lung cancer and colorectal cancer. DESIGN.­: All incidents documented in 2018 were collected from all hospital services for pre-preanalytical entries before the biomarker test, as well as specific incidents for biomarker tests. RESULTS.­: There were 5185 incidents collected, of which 4363 (84.1%) occurred in the pre-preanalytical phase (all hospital services), 2796 of 4363 (64.1%) related to missing or incorrect request form information. From the other 822 specific incidents, 166 (20.2%) were recorded in the preanalytical phase, 275 (33.5%) in the analytical phase, and 194 (23.6%) in the postanalytical phase, mainly due to incorrect report content. Only 47 of 822 (5.7%) incidents were recorded in the post-postanalytical phase, and 123 (15.0%) in the complete total test process. For 17 of 822 (2.1%) incidents the time point was unknown. Pre-preanalytical incidents were resolved sooner than incidents on the complete process (mean 6 versus 60 days). For 1215 of 5168 (23.5%) incidents with known causes a specific action was undertaken besides documenting them, not limited to accredited institutes. CONCLUSIONS.­: There was a large variety in the number and extent of documented incidents. Correct and complete information on the request forms and final reports are highly error prone and require additional focus.

Performance evaluation of the highly sensitive histidine-rich protein 2 rapid test for plasmodium falciparum malaria in North-West Tanzania.

BACKGROUND: Precise detection of Plasmodium infections in community surveys is essential for effective malaria control. Microscopy and rapid diagnostic tests (RDTs) are the major techniques used to identify malaria infections in the field-based surveys. Although microscopy is still considered as the gold standard, RDTs are increasingly becoming versatile due to their rapid and adequate performance characteristics. METHODS: A malaria prevalence cross-sectional survey was carried out in north-western Tanzania in 2016, aimed at appraising the performance of high sensitivity Plasmodium falciparum (HSPf) tests compared to SD Bioline Pf and microscopy in detecting P. falciparum infections. A total of 397 individuals aged five years and above were tested for P. falciparum infections. The sensitivity, specificity, positive, and negative predictive values (PPV and NPV) of microscopy, Pf RDT and HSPf RDT was determined using PCR as the gold standard method. RESULTS: The prevalence of P. falciparum infections determined by microscopy, SD Bioline Pf, HSPf and PCR was 21.9, 27.7, 33.3 and 43.2%, respectively. The new HSPf RDT had significantly higher sensitivity (98.2%) and specificity (91.6%) compared to the routinely used SD Bioline Pf RDT(P < 0.001). The positive predictive value (PPV) was 81.8% and the negative predictive value (NPV) was 99.2% for the routinely used SD Bioline Pf RDT. Moreover, HSPf RDT had sensitivity of 69% and specificity of 76.8% compared to microscopy. The PPV was 45.5% and the NPV was 89.8% for microscopy. Furthermore, the analytical sensitivity test indicated that the newly developed HSPf RDT had lower detection limits compared to routinely used SD Bioline RDT. CONCLUSIONS: HSPf RDT had better performance when compared to both microscopy and the currently used malaria RDTs. The false negativity could be associated with the low parasite density of the samples. False positivity may be related to the limitations of the expertise of microscopists or persistent antigenicity from previous infections in the case of RDTs. Nevertheless, HS PfRDT performed better compared to routinely used Pf RDT, and microscopy in detecting malaria infections. Therefore, HS Pf RDT presents the best alternative to the existing commercial/regularly available RDTs due to its sensitivity and specificity, and reliability in diagnosing malaria infections.

Utility of RSV rapid diagnostic assays in hospitalized children in Amman, Jordan.

BACKGROUND: Respiratory syncytial virus (RSV) is the leading cause of acute respiratory infections in children worldwide and a frequent cause of hospitalization. Rapid diagnostic assays (RDAs) are available for RSV and they help guide management; however, they are underutilized in developing countries. We compared molecular diagnostics to RSV RDA in hospitalized children in Amman, Jordan. MATERIALS AND METHODS: Children under 2 years of age, admitted with fever and/or respiratory symptoms were enrolled prospectively from March 2010 to 2012. Demographic and clinical data were collected through parent/guardian interviews and medical chart abstraction. RSV RDAs were performed, and nasal/throat swabs were tested for RSV using quantitative reverse transcription-polymerase chain reaction (qRT-PCR). RESULTS: RSV RDA and PCR were performed on specimens from 1271 subjects. RSV RDA had a sensitivity of 26% and a specificity of 99%, with positive and negative predictive values of 98.6% and 43%, respectively. RDA-positive patients had fewer days of symptoms at presentation and were more likely to have a history of prematurity, lower birth weight, require supplemental oxygen, and a longer hospitalization as compared with subjects with negative RDA. Multivariate analysis showed only lower birth weight, lack of cyanosis on examination, and lower cycle threshold to be independently associated with positive RDA (p ≤ .001). CONCLUSION: RSV RDAs had high specificity, but low sensitivity as compared with qRT-PCR. Positive RDA was associated with patients with a more severe disease, as indicated by oxygen use, longer length of stay, and higher viral load. Implementation of RDAs in developing countries could be an inexpensive and expedient method for predicting RSV disease severity and guiding management.

How to Set Up a Molecular Pathology Lab: A Guide for Pathologists.

In today's pathology practice, pathologists combine molecular tests with conventional histopathological methods. Pathology laboratories should therefore be designed and operated in accordance with the requirements of molecular testing procedures. While the specifics of the requirements may vary depending on the spectrum of the tests that will be performed, there are several basic criteria that need to be fulfilled for standardization. Adequate space, appropriate equipment and qualified personnel are required to establish a molecular pathology laboratory. One of the most important points that should be taken into consideration while designing a molecular pathology laboratory is to create a plan to prevent contamination. As molecular diagnosis has a major role in treatment decisions, the management of the molecular pathology laboratory is of utmost importance. In this review, the criteria required to establish an optimal molecular pathology laboratory will be reviewed.

De novo mutations in the X-linked TFE3 gene cause intellectual disability with pigmentary mosaicism and storage disorder-like features.

INTRODUCTION: Pigmentary mosaicism (PM) manifests by pigmentation anomalies along Blaschko's lines and represents a clue toward the molecular diagnosis of syndromic intellectual disability (ID). Together with new insights on the role for lysosomal signalling in embryonic stem cell differentiation, mutations in the X-linked transcription factor 3 (TFE3) have recently been reported in five patients. Functional analysis suggested these mutations to result in ectopic nuclear gain of functions. MATERIALS AND METHODS: Subsequent data sharing allowed the clustering of de novo TFE3 variants identified by exome sequencing on DNA extracted from leucocytes in patients referred for syndromic ID with or without PM. RESULTS: We describe the detailed clinical and molecular data of 17 individuals harbouring a de novo TFE3 variant, including the patients that initially allowed reporting TFE3 as a new disease-causing gene. The 12 females and 5 males presented with pigmentation anomalies on Blaschko's lines, severe ID, epilepsy, storage disorder-like features, growth retardation and recognisable facial dysmorphism. The variant was at a mosaic state in at least two male patients. All variants were missense except one splice variant. Eleven of the 13 variants were localised in exon 4, 2 in exon 3, and 3 were recurrent variants. CONCLUSION: This series further delineates the specific storage disorder-like phenotype with PM ascribed to de novo TFE3 mutation in exons 3 and 4. It confirms the identification of a novel X-linked human condition associated with mosaicism and dysregulation within the mechanistic target of rapamycin (mTOR) pathway, as well as a link between lysosomal signalling and human development.

Molecular identification of Leishmania tropica and L. infantum isolated from cutaneous human leishmaniasis samples in central Morocco.

BACKGROUND & OBJECTIVES: Cutaneous leishmaniasis (CL) in Marrakesh-Safi region located in the central-south part of Morocco is a public health problem. This study assessed the efficiency of a microscopic examination method in establishing the diagnosis of CL and PCR for the characterization and identification of the circulating Leishmania strains in different CL foci of the study area. METHODS: A total of 297 smears obtained from cutaneous lesions of suspected patients with CL were stained with May-Grünwald Giemsa (MGG) for microscopic examination. For each positive smear, genomic DNA was extracted and PCR-analysed, targeting the small subunit ribosomal ribonucleic acid (ssu rRNA) gene to detect Leishmania DNA. Then, the internal transcribed spacer 1 (ITS1) was amplified and sequenced in order to identify the Leishmania species. The sensitivity and specificity of the conventional microscopy with ssu rRNA gene were compared by Leishmania nested PCR (LnPCR) and ITS1 gene by ITS-PCR. RESULTS: A total of 257 smears were positive in the microscopic examination, i.e. the detection rate of amastigotes by optical microscopy was 86.53% (257/297). The LnPCR was found to have a specificity and a sensitivity of 100%, each. Interestingly, the sequencing results showed that 99.61% (256/257) of the isolates had Leishmania tropica and 0.39% (1/257) had L. infantum infection. INTERPRETATION & CONCLUSION: Though, classical microscopic examination is useful and economical, it is not sensitive enough, especially in endemic regions where several Leishmania species coexist. In such situations, PCR constitutes a complementary method for the identification of the causal species. The results indicate that both the L. tropica (dominant) and L. infantum are the causative agents of CL in the Marrakesh-Safi region. The rate of CL infection is high in Imintanout, and Chichaoua provinces. Hence, early diagnosis and prompt treatment of CL patients is necessary to prevent its extension to neighboring localities.

CM-Path Molecular Diagnostics Forum-consensus statement on the development and implementation of molecular diagnostic tests in the United Kingdom.

BACKGROUND: Pathology has evolved from a purely morphological description of cellular alterations in disease to our current ability to interrogate tissues with multiple 'omics' technologies. By utilising these techniques and others, 'molecular diagnostics' acts as the cornerstone of precision/personalised medicine by attempting to match the underlying disease mechanisms to the most appropriate targeted therapy. METHODS: Despite the promises of molecular diagnostics, significant barriers have impeded its widespread clinical adoption. Thus, the National Cancer Research Institute (NCRI) Cellular Molecular Pathology (CM-Path) initiative convened a national Molecular Diagnostics Forum to facilitate closer collaboration between clinicians, academia, industry, regulators and other key stakeholders in an attempt to overcome these. RESULTS: We agreed on a consensus 'roadmap' that should be followed during development and implementation of new molecular diagnostic tests. We identified key barriers to efficient implementation and propose possible solutions to these. In addition, we discussed the recent reconfiguration of molecular diagnostic services in NHS England and its likely impacts. CONCLUSIONS: We anticipate that this consensus statement will provide practical advice to those involved in the development of novel molecular diagnostic tests. Although primarily focusing on test adoption within the United Kingdom, we also refer to international guidelines to maximise the applicability of our recommendations.

Neoplastic cell percentage estimation in tissue samples for molecular oncology: recommendations from a modified Delphi study.

AIMS: Results from external quality assessment revealed considerable variation in neoplastic cell percentages (NCP) estimation in samples for biomarker testing. As molecular biology tests require a minimal NCP, overestimations may lead to false negative test results. We aimed to develop recommendations to improve the NCP determination in a prototypical entity - colorectal carcinoma - that can be adapted for other cancer types. METHODS AND RESULTS: A modified Delphi study was conducted to reach consensus by 10 pathologists from 10 countries with experience in determining the NCP for colorectal adenocarcinoma. This study included two online surveys and a decision-making meeting. Consensus was defined a priori as an agreement of > 80%. All pathologists completed both surveys. Consensus was reached for 8 out of 19 and 2 out of 13 questions in the first and second surveys, respectively. Remaining issues were resolved during the meeting. Twenty-four recommendations were formulated. Major recommendations resulted as follows: only pathologists should conduct the morphological evaluation; nevertheless molecular biologists/technicians may estimate the NCP, if specific training has been performed and a pathologist is available for feedback. The estimation should be determined in the area with the highest density of viable neoplastic cells and lowest density of inflammatory cells. Other recommendations concerned: the determination protocol itself, needs for micro- and macro-dissection, reporting and interpreting, referral practices and applicability to other cancer types. CONCLUSION: We believe these recommendations may lead to more accurate NCP estimates, ensuring the correct interpretation of test results, and might help in validating digital algorithms in the future.

Quality of molecular detection of vancomycin resistance in enterococci: results of 6 consecutive years of Quality Control for Molecular Diagnostics (QCMD) external quality assessment.

The quality of PCR to detect vancomycin-resistant enterococci (VRE) was evaluated by analysing their performance in six consecutive external quality assessment (EQA) schemes, organized annually since 2013 by Quality Control for Molecular Diagnostics. VRE EQA panels consisted of 12-14 heat-inactivated samples. Sensitivity was tested with vanA-positive Enterococcus faecium (E. faecium), vanB-positive E. faecium, E. faecalis or E. gallinarum or vanC-positive E. gallinarum in different concentrations. Vancomycin-susceptible enterococci, Staphylococcus aureus or sample matrix was used to study the specificity. Participants were asked to report the VRE resistance status of each sample. The detection rate of vanA-positive samples was already 95% in the 2013 EQA panel (range 94-97%) and remained stable over the years. The 2013 detection rate of vanB-positive samples was 82% but increased significantly by more than 10% in subsequent years (96% in 2014, 95% in 2015, 92% in 2016 and 93% in 2017/2018, p < 0.05). The vanC detection rate by the limited number of assays specifically targeting this gene was lower compared to vanA/B (range 55-89%). The number of false positives in the true-negative sample (8% in 2013 to 1.4% in 2018) as well as the van-gene-negative bacterial samples (4% in 2013 to 0% in 2018) declined over the years. In the six years of VRE proficiency testing to date, the detection of vanA-positive strains was excellent and an increased sensitivity in vanB detection as well as an increase in specificity was observed. Commercial and in-house assays performed equally well.

PCR diagnostics: In silico validation by an automated tool using freely available software programs.

PCR diagnostics are often the first line of laboratory diagnostics and are regularly designed to either differentiate between or detect all pathogen variants of a family, genus or species. The ideal PCR test detects all variants of the target pathogen, including newly discovered and emerging variants, while closely related pathogens and their variants should not be detected. This is challenging as pathogens show a high degree of genetic variation due to genetic drift, adaptation and evolution. Therefore, frequent re-evaluation of PCR diagnostics is needed to monitor its usefulness. Validation of PCR diagnostics recognizes three stages, in silico, in vitro and in vivo validation. In vitro and in vivo testing are usually costly, labour intensive and imply a risk of handling dangerous pathogens. In silico validation reduces this burden. In silico validation checks primers and probes by comparing their sequences with available nucleotide sequences. In recent years the amount of available sequences has dramatically increased by high throughput and deep sequencing projects. This makes in silico validation more informative, but also more computing intensive. To facilitate validation of PCR tests, a software tool named PCRv was developed. PCRv consists of a user friendly graphical user interface and coordinates the use of the software programs ClustalW and SSEARCH in order to perform in silico validation of PCR tests of different formats. Use of internal control sequences makes the analysis compliant to laboratory quality control systems. Finally, PCRv generates a validation report that includes an overview as well as a list of detailed results. In-house developed, published and OIE-recommended PCR tests were easily (re-) evaluated by use of PCRv. To demonstrate the power of PCRv, in silico validation of several PCR tests are shown and discussed.

HistoQC: An Open-Source Quality Control Tool for Digital Pathology Slides.

PURPOSE: Digital pathology (DP), referring to the digitization of tissue slides, is beginning to change the landscape of clinical diagnostic workflows and has engendered active research within the area of computational pathology. One of the challenges in DP is the presence of artefacts and batch effects, unintentionally introduced during both routine slide preparation (eg, staining, tissue folding) and digitization (eg, blurriness, variations in contrast and hue). Manual review of glass and digital slides is laborious, qualitative, and subject to intra- and inter-reader variability. Therefore, there is a critical need for a reproducible automated approach of precisely localizing artefacts to identify slides that need to be reproduced or regions that should be avoided during computational analysis. METHODS: Here we present HistoQC, a tool for rapidly performing quality control to not only identify and delineate artefacts but also discover cohort-level outliers (eg, slides stained darker or lighter than others in the cohort). This open-source tool employs a combination of image metrics (eg, color histograms, brightness, contrast), features (eg, edge detectors), and supervised classifiers (eg, pen detection) to identify artefact-free regions on digitized slides. These regions and metrics are presented to the user via an interactive graphical user interface, facilitating artefact detection through real-time visualization and filtering. These same metrics afford users the opportunity to explicitly define acceptable tolerances for their workflows. RESULTS: The output of HistoQC on 450 slides from The Cancer Genome Atlas was reviewed by two pathologists and found to be suitable for computational analysis more than 95% of the time. CONCLUSION: These results suggest that HistoQC could provide an automated, quantifiable, quality control process for identifying artefacts and measuring slide quality, in turn helping to improve both the repeatability and robustness of DP workflows.