As tumor mutational burden (TMB) has been approved as a predictive biomarker for immune checkpoint inhibitors (ICIs), next-generation sequencing (NGS) TMB panels are being increasingly used clinically. However, only a few of them have been validated in clinical trials or authorized by administration. The harmonization and standardization of TMB panels are thus essential for clinical implementation. In this review, preanalytic, sequencing, bioinformatics and interpretative factors are summarized to provide a comprehensive picture of how the different factors affect the estimation of panel-based TMB. Among the factors, poor DNA quality, improper formalin fixation and residual germline variants after filtration may overestimate TMB, while low tumor purity may decrease the sensitivity of the TMB panel. In addition, a small panel size leads to more variability when comparing with true TMB values detected by whole-exome sequencing (WES). A panel covering a genomic region of more than 1Mb is more stable for harmonization and standardization. Because the TMB estimate reflects the sum of effects from multiple factors, deliberation based on laboratory and specimen quality, as well as clinical information, is essential for decision making.

Background The purpose of the current study was to examine the impact of coronavirus disease 2019 (COVID‐19) on various aspects of cytology practice in the Asia‐Pacific region. Methods An online questionnaire was distributed to cytopathology laboratories in 24 Asia‐Pacific countries to explore the impact of restrictive measures on access to health care, use of general and personal protective equipment (PPE), and changes in cytology workflow and workload from February to April 2020. Results A total of 167 cytopathology laboratories from 24 countries responded to the survey; the majority reported that restrictive measures that limited the accessibility of health care services had been implemented in their cities and/or countries (80.8%) and their hospitals (83.8%). The respondents noted that COVID‐19 had an impact on the cytologic workflow as well as the workload. Approximately one‐half of the participants reported the implementation of new biosafety protocols (54.5%) as well as improvements in laboratory facilities (47.3%). Rearrangement or redeployment of the workforce was reported in 53.3% and 34.1% of laboratories, respectively. The majority of the respondents reported a significant reduction (>10%) in caseload associated with both gynecological (82.0%) and nongynecological specimens (78.4%). Most laboratories reported no significant change in the malignancy rates of both gynecological (67.7%) and nongynecological specimens (58.7%) compared with the same period in 2019. Conclusions The results of the survey demonstrated that the COVID‐19 pandemic resulted in a significant reduction in the number of cytology specimens examined along with the need to implement new biosafety protocols. These findings underscore the need for the worldwide standardization of biosafety protocols and cytology practice.

Diabetes mellitus (DM) is a common chronic metabolic disease, and the C57BLKsJ-db/db mice are good animal models for type 2 diabetes mellitus (T2DM). In this study, Western blotting and immunohistochemistry (IHC) were employed to examine the protein expression of adiponectin in the liver tissues of T2DM mice with different disease courses (4, 16, and 32 weeks). Adiponectin expression reduced in the liver tissues of T2DM mice in different disease courses. The genotypic and allelic frequencies of the adiponectin gene rs1063538 and rs2241766 single nucleotide polymorphisms (SNPs) in a Taiwanese population (570 T2DM patients and 1700 controls) were investigated. Based on the genetic distribution of the rs2241766 locus, the distribution frequency of the T allele in the T2DM group (72.8%) was higher than in the control group (68.8%). Individuals carrying the G allele had a 0.82-fold greater risk of developing T2DM than individuals carrying the T allele. Differences were evident in the genotypic and allelic distributions (p < 0.05). Enzyme-linked immunosorbent assay (ELISA) was used to measure changes in serum adiponectin protein concentrations in the healthy population and in patients with T2DM. Serum adiponectin concentration in patients with T2DM was lower than in the control group. In summary, adiponectin was determined to be a T2DM susceptibility gene and may be involved in T2DM progression.

Cholesteryl ester transfer protein (CETP) plays an important role in lipid metabolism. Low levels of high-density lipoprotein cholesterol (HDL-C) increase the risk of type 2 diabetes (T2D). This study investigated CETP gene variants to assess the risk of T2D and specific complications of diabetic kidney disease (DKD) and diabetic retinopathy. Towards this, a total of 3023 Taiwanese individuals (1383 without T2D, 1640 with T2D) were enrolled in this study. T2D mice (+Lepr^db/+Lepr^db, db/db) were used to determine CETP expression in tissues. The A-alleles of rs3764261, rs4783961, and rs1800775 variants were found to be independently associated with 2.86, 1.71, and 0.91 mg/dL increase in HDL-C per allele, respectively. In addition, the A-allele of rs4783961 was significantly associated with a reduced T2D risk (odds ratio (OR), 0.82; 95% confidence interval (CI), 0.71–0.96)), and the A-allele of rs1800775 was significantly related to a lowered DKD risk (OR, 0.78; 95% CI, 0.64–0.96). CETP expression was significantly decreased in the T2D mice kidney compared to that in the control mice (T2D mice, 0.16 ± 0.01 vs. control mice, 0.21 ± 0.02; p = 0.02). These collective findings indicate that CETP variants in the promoter region may affect HDL-C levels. Taiwanese individuals possessing an allele associated with higher HDL-C levels had a lower risk of T2D and DKD.

Diabetic retinopathy (DR) is a severe and recurrent microvascular complication in diabetes. The multifunctional response gene to complement 32 (RGC-32) is involved in the regulation of cell cycle, proliferation, and apoptosis. To investigate the role of RGC-32 in the development of DR, we used human retinal microvascular endothelial cells under high-glucose conditions and type 2 diabetes (T2D) mice (+Lepr^db/ + Lepr^db, db/db). The results showed that RGC-32 expression increased moderately in human retinal endothelial cells under hyperglycemic conditions. Histopathology and RGC-32 expression showed no significant changes between T2D and control mice retina at 16 and 24 weeks of age. However, RGC-32 expression was significantly decreased in T2D mouse retina compared to the control group at 32 weeks of age, which develop features of the early clinical stages of DR, namely reduced retinal thickness and increased ganglion cell death. Moreover, immunohistochemistry showed that RGC-32 was predominantly expressed in the photoreceptor inner segments of control mice, while the expression was dramatically lowered in the T2D retinas. Furthermore, we found that the level of anti-apoptotic protein Bcl-2 was decreased (approximately 2-fold) with a concomitant increase in cleaved caspase-3 (approximately 3-fold) in T2D retina compared to control. In summary, RGC-32 may lose its expression in T2D retina with features of DR, suggesting that it plays a critical role in DR pathogenesis.

In the Paris System (TPS), standardized cytomorphological criteria and diagnostic categories were proposed for reporting urine cytology. To evaluate the diagnostic agreement and interobserver concordance for assessing TPS criteria, the Taiwan Society of Clinical Cytology organized an online survey with 10 atypical urine cytology cases. A total of 137 participants completed the survey. The mean agreement of diagnosis was 51.2%, ranging from 34.3% to 83.2% for each case. For 60% (6/10) of cases, the agreement was <50%. The interobserver concordance of diagnosis and cytological criteria assessment showed poor agreement. The nuclear-to-cytoplasmic (N/C) ratio had the highest kappa value of 0.386, indicating a significantly higher interobserver concordance and reproducibility than the other three TPS criteria. The correct rate of assessing the N/C ratio increased as the N/C ratio increased (correlation coefficient: 0.891, p < 0.01). Three cases with an N/C ratio near 0.5 were overestimated. Poor interobserver concordance of diagnosis and TPS criteria was revealed. Compared with other cytological features, the N/C ratio assessment was quantitative and more reproducible, but a tendency to overestimate cells was noted when the N/C ratio was approximately 0.5. Continuing education programs should emphasize the accurate assessment of N/C ratio to improve the application of TPS.