American journal of clinical pathology最新文献

Objective: We evaluated the clinical performance of Roche Digital Pathology Dx, a whole slide imaging (WSI) system, in 2 studies according to US Food and Drug Administration (FDA) and Digital Pathology Association criteria.

Methods: Precision was measured by pathologists identifying 23 histopathology features; accuracy was assessed by comparing diagnoses from 2047 clinical cases with those from manual microscopy, with exploratory analyses including subgroup-specific diagnostic discrepancy rates.

Results: Both studies met all predetermined primary endpoints. Precision between systems/sites was 89.3%; between days, 90.3%; and between readers, 90.1% (lower bound of 95% CI for each, ≥85%). The difference in accuracy between digital reads (DRs) and manual microscopy reads (MRs) vs reference sign-out diagnosis (SD), DRs - MRs, was -0.61% (lower bound of 95% CI, -1.59%), which was greater than the lower bound acceptance criterion (-4%). Mean case reading times were similar: 2.33 minutes (DRs) and 2.34 minutes (MRs). Review of breast, lung, bladder, kidney, and stomach case diagnoses did not identify DR modality-specific root causes for major diagnostic disagreements. Higher than expected disagreements in both modalities were traced to COVID-19 pandemic-related resource constraints, leading to challenging case adjudications and higher disagreement rates for longer SDs. Direct DR/MR adjudication supported this hypothesis, resulting in an intermodality disagreement rate of 4.77%; using SD as a "tiebreaker" reduced the overall DR disagreement rate to 2.97%.

Conclusions: Roche Digital Pathology Dx is noninferior to manual microscopy for primary diagnosis in surgical pathology, with performance results similar to 5 distinct FDA-cleared WSI systems using different scanners.

Objective: Due to low malaria prevalence, implementation of the only US Food and Drug Administration (FDA)-cleared rapid malaria diagnostic, BinaxNOW Malaria, in US clinical laboratories is challenging due to limited clinical specimens for test verification. We describe the initial BinaxNOW evaluation at an academic medical center and its verification across a large health care network with site-based microbiology laboratories, using well-characterized, previously tested blood samples.

Methods: For the initial evaluation, we compared the BinaxNOW Malaria to blood smear examination in 294 whole-blood specimens at the primary evaluation site. For subsequent site-based verification, each site tested 10 previously malaria antigen-positive and 10 previously malaria antigen-negative whole-blood specimens. Positive percent agreement (PPA), negative percent agreement (NPA), concordance, and reproducibility were calculated.

Results: For the initial evaluation, the BinaxNOW Malaria correctly identified Plasmodium species in 100% of specimens positive for Plasmodium falciparum with 96% identified to the species level. Overall BinaxNOW Malaria test sensitivity and specificity were 100%. For the subsequent site-based verification, PPA, NPA, concordance, and reproducibility were 100%.

Conclusions: The approach described provides proof of concept for BinaxNOW Malaria test verification in areas with low malaria prevalence using archived well-characterized blood samples. With this strategy, rapid malaria antigen testing could be expanded, improving diagnostic capabilities across the United States.

Objective: Panfungal sequencing (PFS) using formalin-fixed, paraffin-embedded (FFPE) tissue aids genus-level or species-level identification in suspected invasive fungal infections. Given the limited availability of PFS and potential risk of environmental contamination, defining histopathologic features predictive of clinically interpretable results is important.

Methods: We evaluated FFPE tissue samples submitted for PFS over a 5-year period. Histopathologic data were extracted from pathology reports; in-house cases were re-reviewed, and the burden of fungal elements was assessed using Grocott methenamine silver stain. Any available fungal culture data were also obtained for in-house cases.

Results: Of 153 cases with fungal elements reported by histopathology, 54% were positive by PFS. Of 97 cases without histologic evidence of fungal elements, only 9% were positive by PFS, and all were considered potential environmental contaminants. Culture results were available for only 9 of 461 (2%) cases, and all cultures were concordant with the PFS results. When the pathologist proposed 1 or more specific organisms based on histologic appearance alone, PFS was discrepant in 37% of cases. Of those discrepant diagnoses, and if we designate the PFS result as the true diagnosis, then 53% of misclassifications had the potential for administration of suboptimal antifungal therapy. There was no correlation between the relative abundance of fungal elements in tissue sections and detection of fungal organisms by PFS.

Conclusions: Panfungal sequencing can provide genus-level and species-level identification in the setting of visible fungal elements in FFPE tissue. It is a valuable diagnostic tool, particularly when fungal infections are clinically suspected but fungal cultures were not performed.

Objectives: Liquid plasma (LP) is an increasingly utilized blood product due to its immediate availability for transfusion without requiring thawing. While concerns exist regarding the presence of intact residual red blood cells (RBCs) in plasma products that have never been frozen, limited data are available on their levels in LP. This study aimed to evaluate residual RBC content in LP products to assess their safety for transfusion.

Methods: Liquid plasma units were prepared from whole-blood donations at the Stanford Blood Center. Seven group AB-positive, 1 group AB-negative, 10 group A-positive, and 2 group A-negative whole-blood units were collected in citrate phosphate dextrose anticoagulant, stored at 1 °C to 6 °C for 24 hours, centrifuged, and processed into LP. On day 2 of storage, 2-mL plasma samples were analyzed for RBC count, hemoglobin, and hematocrit.

Results: No residual RBCs were detected in any LP units, with all samples showing RBC counts below the limit of detection, hemoglobin levels of 0 g/dL, and hematocrit values of 0%. Given the uniform absence of RBC contamination, statistical analysis was not required.

Conclusions: The findings confirm that LP prepared under current blood processing standards contains no detectable residual RBCs, supporting its safety for transfusion with ABO-compatible products without the need for consideration of RhD compatibility.

Objective: Immune receptor translocation-associated 1 (IRTA1) expression, which has recently been shown to be highly specific for marginal zone lymphoma, is found in only a subset of extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma). In this study, we examined whether IRTA1 expression in MALT lymphoma was dependent on anatomic location.

Methods: IRTA1 immunohistochemistry was performed in 60 cases of extranodal MALT lymphoma, arising at breast, conjunctiva, lung, salivary gland, skin, and stomach (10 cases each). Expression was also scored with respect to detailed morphologic features.

Results: IRTA1 staining was identified in 25 (42%) cases, ranging from 9 (90%) of 10 in lung to 2 (20%) of 10 in gastric MALT lymphoma. IRTA1 staining was not characteristic of specific morphologic features, as it was absent in most lymphoepithelial lesions, perifollicular cells, cells with overt monocytoid cytology, and plasmacytic cells. IRTA1 expression was also identified in 5 (50%) of 10 cases of pulmonary nodular lymphoid hyperplasia.

Conclusions: IRTA1 expression is heterogeneous in extranodal MALT lymphoma. Staining for IRTA1 is not characteristic of specific morphologic features, but varies with the anatomic site of disease. Knowledge of site-specific differences in MALT lymphomas will facilitate diagnosis in routine clinical practice.

Objective: Advances in digital pathology and artificial intelligence have the potential to enhance cytopathology practice. The objective of this study was to compare the performance of the Hologic Genius Digital Diagnostics System with manual glass slide review for Papanicolaou test interpretation.

Methods: Three cytologists retrospectively reviewed 596 Papanicolaou tests using both the Genius Digital Diagnostics System and manual review, with a 4-week washout period between reviews. The study set consisted of 299 Papanicolaou tests originally interpreted as negative for intraepithelial lesion or malignancy and 297 tests originally interpreted as atypical squamous cells of undetermined significance or above (ASC-US+). Cases interpreted as ASC-US+, reactive/repair, or endometrial cells in a woman older than 45 years of age were additionally reviewed by 1 of 5 cytopathologists. Concordance was calculated between each method and the original cytologic interpretation (reference standard). Sensitivity and specificity for detection of high-grade disease were determined for each method. Cytologist review time per case was recorded.

Results: Digital interpretation was concordant with the original interpretation in 578 of 596 (97%) cases, while manual interpretation was concordant with the original interpretation in 577 of 596 (97%) cases. Digital review had higher sensitivity for detection of high-grade disease than manual review did (100% vs 86%) but was less specific (93% vs 98%). The average digital review time per case was statistically significantly shorter than manual review time (194.5 seconds vs 485.0 seconds, P < .001).

Conclusions: Papanicolaou test interpretation using the Genius Digital Diagnostics System is noninferior to manual review. Digital review had higher sensitivity for detection of high-grade disease and statistically significantly reduced screening time.

Objective: Somatic hypermutation at immunoglobulin heavy chain variable (IGHV) genes, an established prognostic and predictive biomarker for chronic lymphocytic leukemia (CLL), is assessed by gene sequencing. We developed a single methylation-specific droplet digital polymerase chain reaction (methyl-ddPCR) to predict IGHV status in patients with CLL.

Methods: The CLL methylation array and IGHV data from the International Cancer Genome Consortium (ICGC) were used for biomarker discovery. Top-ranked candidate regions were manually screened for PCR primer and probe binding sites. A single methyl-ddPCR was evaluated on an internal cohort of CLLs with mutated (M), unmutated (U), and inconclusive IGHV results originally determined by next-generation sequencing (NGS).

Results: Analysis of ICGC data identified array probe cg23844018 as a candidate for the PCR. The corresponding CpG site showed high methylation levels in U-CLL and lower levels in M-CLL. On the internal cohort, a single optimal cutoff correctly classified 104 of 115 U- and M-CLLs (90.4%; area under the curve = 0.96). The PCR data correlated with some prognostic fluorescence in situ hybridization and CLL subset groupings. Limited analysis suggests that the PCR may be able to stratify some patients with CLL who have inconclusive results on IGHV NGS testing.

Conclusions: The methyl-ddPCR showed high concordance with CLL IGHV status in an internal cohort.

Objective: Clinical pathology curriculum assessment at our institution suggested improvements in coagulation, histocompatibility, and immunology. We created a 4-week rotation inclusive of these fields, and we describe here the curriculum and experience residents have had.

Methods: Didactic lectures, assigned reading, time at the bench, online modules, and case study discussions were implemented. There were 2 weeks of morning activities dedicated to histocompatibility, while the other 2 weeks were dedicated to immunology. Afternoons were dedicated to special coagulation. Resident surveys and medical knowledge assessments were completed at the beginning and end of the rotation.

Results: We included in this analysis 22 residents. The average knowledge quiz score before the rotation was 15.7 (48% [range, 8-23]) correct answers, while the average score after the rotation was 25 (76% [range, 19-29]), corresponding to a 28% increase in scores. On a Likert scale of 1 to 5, 88% of trainees ranked the rotation at a 4. After the rotation, residents felt more confident interpreting studies for the 3 subspecialties, particularly for special coagulation.

Conclusions: Residents liked the rotation, and their evaluations demonstrate an increase in medical knowledge after the rotation. The training described here can be adapted to teach other compatible clinical pathology subspecialties.

Objective: Flow cytometric T-cell subtyping is an important component of bronchoalveolar lavage (BAL) analysis with diagnostic value in routine practice.

Methods: BAL fluid was collected for differential and standard 4-color panel T-cell subtype analysis using flow cytometry, followed by a 10-color comprehensive T-cell panel to confirm CD4 T-cell antigen loss.

Results: Here, we report 4 BAL cases that were incidentally identified during our daily practice over the past 5 years and showed apparent loss of detectable surface CD4 on CD3+ T cells by 2 different anti-CD4 clones. Each of these BAL fluids was rich in neutrophils and had infectious microorganisms identified on microbiological examination, including Pseudomonas aeruginosa, Haemophilus influenzae, and Mycobacterium avium complex. The dual CD4- and CD8-negative CD3+ T cells were confirmed to express α/β but not γ/δ T-cell receptor in 1 case.

Conclusions: CD4 antigen loss on CD3+ T cells may be seen in neutrophil-predominant BAL fluid specimens that contain infectious microorganisms. The underlying mechanism for CD4 antigen loss is unclear but may involve proteolytic cleavage by protease and/or elastase of either neutrophilic or microbial origin, or possibly chronic antigenic stimulation. Awareness of this diagnostic pitfall is important in clinical practice to avoid misinterpretation of a falsely low CD4/CD8 ratio or a population of T cells lacking expression of CD4 and CD8 in BAL samples.