Diagnostic Assessment of Deep Learning Algorithms for Frozen Tissue Section Analysis in Women with Breast Cancer.

PURPOSE: Assessing the metastasis status of the sentinel lymph nodes (SLNs) for hematoxylin and eosin-stained frozen tissue sections by pathologists is an essential but tedious and time-consuming task that contributes to accurate breast cancer staging. This study aimed to review a challenge competition (HeLP 2019) for the development of automated solutions for classifying the metastasis status of breast cancer patients. Materials and Methods: A total of 524 digital slides were obtained from frozen SLN sections: 297 (56.7%) from Asan Medical Center (AMC) and 227 (43.4%) from Seoul National University Bundang Hospital (SNUBH), South Korea. The slides were divided into training, development, and validation sets, where the development set comprised slides from both institutions and training and validation set included slides from only AMC and SNUBH, respectively. The algorithms were assessed for area under the receiver operating characteristic curve (AUC) and measurement of the longest metastatic tumor diameter. The final total scores were calculated as the mean of the two metrics, and the three teams with AUC values greater than 0.500 were selected for review and analysis in this study. RESULTS: The top three teams showed AUC values of 0.891, 0.809, and 0.736 and major axis prediction scores of 0.525, 0.459, and 0.387 for the validation set. The major factor that lowered the diagnostic accuracy was micro-metastasis. CONCLUSION: In this challenge competition, accurate deep learning algorithms were developed that can be helpful for making a diagnosis on intraoperative SLN biopsy. The clinical utility of this approach was evaluated by including an external validation set from SNUBH.

Comparison of the Abbott RealTime High-Risk Human Papillomavirus (HPV), Roche Cobas HPV, and Hybrid Capture 2 assays to direct sequencing and genotyping of HPV DNA.

Infection with high-risk (HR) human papillomavirus (HPV) genotypes is an important risk factor for cervical cancers. We evaluated the clinical performances of two new real-time PCR assays for detecting HR HPVs compared to that of the Hybrid Capture 2 test (HC2). A total of 356 cervical swab specimens, which had been examined for cervical cytology, were assayed by Abbott RealTime HR and Roche Cobas HPV as well as HC2. Sensitivities and specificities of these assays were determined based on the criteria that concordant results among the three assays were regarded as true-positive or -negative and that the results of genotyping and sequencing were considered true findings when the HPV assays presented discrepant results. The overall concordance rate among the results for the three assays was 82.6%, and RealTime HR and Cobas HPV assays agreed with HC2 in 86.1% and 89.9% of cases, respectively. The two real-time PCR assays agreed with each other for 89.6% of the samples, and the concordance rate between them was equal to or greater than 98.0% for detecting HPV type 16 or 18. HC2 demonstrated a sensitivity of 96.6% with a specificity of 89.1% for detecting HR HPVs, while RealTime HR presented a sensitivity of 78.3% with a specificity of 99.2%. The sensitivity and specificity of Cobas HPV for detecting HR HPVs were 91.7% and 97.0%. The new real-time PCR assays exhibited lower sensitivities for detecting HR HPVs than that of HC2. Nevertheless, the newly introduced assays have an advantage of simultaneously identifying HPV types 16 and 18 from clinical samples.

Detection and genotyping of human papillomavirus by five assays according to cytologic results.

Five assays for the detection of human papillomavirus (HPV) with different assay principles were evaluated. A total of 230 cervical swab specimens were collected from subjects according to the cytologic results. All specimens were tested by the following assays: hybrid capture 2 (HC2), two real-time PCR assays (Abbott RealTime HR and AdvanSure RealTime), liquid beads microarray (GeneFinder) and peptide nucleic acid-based array (PANArray). The HPV DNA of 99 samples was sequenced to identify genotypes. Concordance rates between the results for the identification of 14 high risk HPV genotypes by any two of the evaluated assays, except for AdvanSure RealTime, ranged from 83.0% to 88.3%, and those for the identification of genotypes 16 and 18, except for HC2, were 93.0% and 96.1%, respectively. The results for the evaluation of high risk HPV genotypes by HC2 agreed with those of the other assays in 76.5-86.5% of cases. Identification of HPV genotype by GeneFinder and PANArray corresponded with that by direct sequencing in 88.9% and 84.8% of sequenced samples. This study demonstrated that HC2 and the two real-time PCR assays could be used for routine HPV screening, and the other genotyping assays can be applied for epidemiologic surveillance.

Evaluation of revisited fucosylated alpha-fetoprotein (AFP-L3) with an autoanalyzer µTAS in a clinical laboratory.

BACKGROUND: We assessed clinical and analytical performances of AFP and fucosylated AFP (AFP-L3) assays by a newly developed automated analyzer based on liquid-phase binding (micro-total analysis systems, µTAS). METHODS: A total of 239 serum samples were obtained from 120 patients with hepatocellular carcinoma (HCC) and 119 without HCC. Precision of assays by the µTAS was evaluated, and the correlation between AFP-L3 and AFP levels was analyzed. Receiver operating characteristics curve-area under the curve (ROC-AUC) value was calculated to measure the diagnostic performance. RESULTS: Imprecision for AFP (ng/ml), AFP-L3 (ng/ml), and AFP-L3 (%) with 2 levels of QC materials was all within 5% coefficient of variation. AFP levels measured by the µTAS were correlated well with those by the UniCel DxI 800 Access (r=0.83). AFP-L3 concentrations in HCC patients were higher than those in control group (median 379.2 ng/ml in HCC, 1.0 ng/ml in non-HCC, P<0.05). AUC of AFP-L3 was 0.91 which was significantly higher than that of AFP (0.88 by µTAS; 0.84 by UniCel DxI 800, P<0.05 for both). CONCLUSION: AFP-L3 in HCC was significantly higher than that of control group. The µTAS showed good performances for routine uses in clinical laboratories for measuring AFP and AFP-L3.

Performance evaluation of the Vitros anti-hepatitis C virus antibody assay for use in clinical laboratories.

OBJECTIVES: We evaluated the performance of Vitros anti-HCV assay. DESIGN AND METHODS: Precision performance was assessed for 20 days. A total of 1011 sera were tested for anti-HCV with Vitros and Elecsys assays. Specimens positive for any of the two assays were retested with Architect assay. Discrepant results were evaluated with recombinant immunoblot assay (RIBA) and HCV RNA quantification. RESULTS: Total imprecision of Vitros assay was 11.6% and 3.3% CV for negative and positive QC. Among the 1011 sera, 17 showed discrepant results between the three assays. Six were positive and three negative for RIBA. HCV RNA was not detected from all discrepant cases. Sensitivity and specificity were 99.5% and 99.5% for the Vitros, and 100.0% and 99.9% for the Elecsys assay. CONCLUSIONS: Sensitivities and specificities of the anti-HCV assays were sufficiently high for use in clinical laboratories, but retesting of weak positive results may be necessary.

Urinary iodine and sodium status of urban Korean subjects: a pilot study.

OBJECTIVES: We estimated iodine status of Korean population by determining the concentration of spot urinary iodine (UI) with a reliable method based on the Sandell-Kolthoff reaction. MATERIALS AND METHODS: A total of 540 urine samples from apparently healthy subjects were collected, and UI, urinary sodium (UNa), and urinary creatinine (UCr) were determined from those samples and analyzed with age. RESULTS: There were significant decreases in either UI (P<0.0001), UI/UCr ratio (P=0.0001), UNa (P<0.0001), or UNa/Cr ratio (P=0.0001) in younger subjects than older ones. The median value of UI was 267.6 µg/L, but the median UI of the younger group (191.8 µg/L) was significantly decreased compared to that of the older group (383.9 µg/L). CONCLUSIONS: This study showed that the median of UI in Korean urban population was in a more than adequate iodine nutritional state, but UI was significantly different between the younger age group and the older age group.

Anaphylactic transfusion reaction in a patient with anhaptoglobinemia: the first case in Korea.

Anaphylactic transfusion reactions are rare complications of blood transfusions. Anhaptoglobinemia, a condition that has high incidence in Asia, can cause allergic transfusion reactions or anaphylaxis in severe cases. A 50-yr-old Korean woman was diagnosed with relapsed acute promyelocytic leukemia. She developed thrombocytopenia during chemotherapy and an anaphylactic transfusion reaction on the 4th and 5th platelet transfusions immediately after the transfusion of the platelet concentrates was initiated. Blood analysis showed no detectable serum haptoglobin. We examined her genetic phenotype and detected anhaptoglobinemia, which occurs because of an allelic deletion in the Hp gene cluster. The presence of an antibody against haptoglobin was detected by performing ELISA. To prevent anaphylactic reactions, apheresis platelets were transfused after washing. Consequently, anaphylactic transfusion reactions did not develop. Here, we report the first case of anhaptoglobinemia causing anaphylactic transfusion reaction in Korea.

Evaluation of automated serum des-gamma-carboxyprothrombin (DCP) assays for detecting hepatocellular carcinoma.

OBJECTIVES: We evaluated two new autoanalyzers, µTAS and Lumipulse for des-γ-carboxyprothrombin (DCP) assay. MATERIAL AND METHODS: Analytical performance was evaluated, and the upper reference limit of the 97.5th percentile for DCP was re-established using sera from 140 healthy individuals. DCP levels were determined by the two autoanalyzers and EIA in a total of 239 sera from HCC patients (n=120) and those without HCC (n=119). RESULTS: Total imprecision of the two automated assays was <5% CV. Analytical measurement ranges (AMRs) were verified to be linear. The new reference limits were 29.5 mAU/mL for µTAS and 35.0 mAU/mL for Lumipulse. There were proportional and constant biases between the results from the autoanalyzers and those from EIA. CONCLUSION: The two newly developed DCP assays showed high analytical performance, but re-establishment of reference limits would be necessary. The new analyzers could be useful for clinical laboratories because of convenience of operation and wide AMRs.

Subcutaneous phaeohyphomycosis caused by Phaeoacremonium species in a kidney transplant patient: the first case in Korea.

Phaeohyphomycosis is a subcutaneous infection caused by dark pigmented fungi, including fungi of the species Phaeoacremonium, Alternaria, Exophiala, and Pyrenochaeta. In August 2005, a 54-yr-old man who had received a renal transplant 5 yr ago was admitted to our hospital with a subcutaneous mass on the third finger of the right hand; the mass had been present for several months. He had been receiving immunosuppressive agents for several years. He underwent excision of the mass, which was followed by aspiration of the wound for bacterial and fungal cultures. Many fungal hyphae were observed on the histology slide treated with periodic acid-Schiff stain. A few white waxy colonies with a woolly texture grew on the Sabouraud dextrose agar at 30°C and changed to dark brown in color. Nucleotide sequencing of internal transcribed spacer regions revealed 100% homology to the Phaeoacremonium aleophilum anamorph and Togninia minima teleomorph (514 bp/514 bp). The patient completely recovered after wide surgical excision. Here, we report the first case of phaeohyphomycosis caused by Phaeoacremonium species in a kidney transplant patient in Korea.

A rare splicing mutation in the PROS1 gene of a Korean patient with type I hereditary protein S deficiency.

Hereditary protein S (PS) deficiency (Gene ID: 5627; MIM # 176880) is a notable risk factor for recurrent venous thrombosis, inherited as an autosomal-dominant trait, either homozygous or heterozygous. It may be caused by point mutations in the gene (PROS1) encoding PS, which contains 15 exons on the chromosome 3q11.2. Only a few point mutations associated with the PROS1 gene in patients with hereditary PS deficiency have been reported. A 60-year-old woman was admitted for deep vein thrombosis (DVT) of the right lower extremity. Upon coagulation examination, both the free PS antigen level and the total PS antigen level were decreased, so the DNA-PCR products of all 15 exons, including the exon-intron boundaries of the PROS1, gene were directly sequenced. A substitution from guanine to adenine at position +5 of the donor splice site of intron 10 (c.1155+5G>A) was identified. Further familial study was performed, and the patient's older sister was revealed to have the same mutation; she was already taking warfarin due to diagnosed pulmonary thromboembolism. Here we report a G to A transition at position +5 of intron 10 from the splice donor site as a rare case of a patient with type I hereditary PS deficiency in Korea.

Characteristics of clinical isolates of Acinetobacter genomospecies 10 carrying two different metallo-beta-lactamases.

Acquired metallo-beta-lactamase (MBL) production is an important mechanism of carbapenem resistance. To our knowledge, carriage of two different MBLs has not been described previously in Acinetobacter spp. We present the characteristics of five Acinetobacter isolates carrying two different MBL genes. The species of all five Acinetobacter isolates with two different MBL genes were Acinetobacter genomospecies 10, and bla(IMP-1), bla(VIM-2) and bla(SIM-1) may coexist in this species. Minimum inhibitory concentrations (MICs) of imipenem for all five isolates with two different MBLs were >or=32 microg/mL, whilst those for two segregants that lost both MBLs were 0.5 microg/mL. The presence of MBL gene-carrying integrons with identical structures suggested the easily transferable nature of the elements, whilst instability of the MBL genes indicated potentially erroneous phenotypic and genetic characterisation.