Banff-based histologic chronicity index is associated with graft failure but has poor interobserver reproducibility.

BACKGROUND: Antibody-mediated rejection (AMR) often leads to chronic kidney allograft damage and is a critical cause of allograft failure. The Banff classification, used to diagnose AMR, has become complex and challenging for clinicians. A Banff-based histologic chronicity index (CI) was recently proposed as a simplified prognostic indicator. Its reliability and reproducibility have not been externally validated. METHODS: This study investigated 71 kidney allograft biopsies diagnosed with AMR. Interobserver reproducibility of the recently proposed CI and its components (cg, cv, ct, and ci) were assessed. The association between CI and allograft failure was analyzed, and CI cut-off values were evaluated by Cox proportional hazards regression and Kaplan-Meier estimator with log-rank test. RESULTS: The study confirmed the association of CI with allograft failure, but also revealed that the assessment of CI varied between pathologists, impacting its reproducibility as a prognostic tool. Only 49 (69.0%) of the biopsies showed complete agreement on the proposed cut-off value of CI < 4 or CI ≥ 4. Furthermore, this cut-off did not reliably stratify allograft failure. Notably, the cg score, which carries significant weight in the CI calculation, had the lowest agreement between observers (kappa = .281). CONCLUSIONS: While a simplified prognostic indicator for AMR is needed, this study highlights the limitations of CI, particularly its poor interobserver reproducibility. Our findings suggest that clinicians should interpret CI cautiously and consider establishing their own cut-off values. This study underscores the need to address interobserver reproducibility before CI can be widely adopted for AMR management.

Hepatic and Extrahepatic Characteristics of Autoimmune Hepatitis: A 23-year Hospital-Based Cohort Study.

BACKGROUND: The characteristics of autoimmune hepatitis (AIH) in Asia mostly remain elusive. METHODS: A cohort study of liver biopsy-proven AIH patients was conducted in a tertiary care cancer of Taiwan. RESULTS: From 1999 to 2022, of 13,766 patients who underwent liver biopsy, 150 patients with AIH were enrolled. The female-to-male ratio was 2.26. At baseline, the mean age was 51.09 years, mean alanine aminotransferase level was 494.11 U/L, and 17 (11.3%) had cirrhosis. All except one patient had AIH type 1. The females were older and had higher baseline cirrhosis rates than did the males. The 23-year cumulative incidences of cirrhosis, hepatocellular carcinoma (HCC), mortality/liver transplantation, autoimmune diseases and extrahepatic cancer were 64.2%, 13.3%, 23.4%, 30.7% and 21.2%, respectively. The 1-year, 2-year, 3-year, 5-year, 10-year and 20-year postimmunosuppressive therapy relapse rates were 60%, 78.2%, 81.8%, 89.1%, 94.5% and 100%, respectively. Baseline associations were as follows: alkaline phosphatase (Alk-p) levels with postimmunosuppressive therapy flare [hazard ratio (HR): 1.003; 95% CI HR: 1.000-1.005]; age with HCC (1.072; 1.010-1.138) and all-cause cancer (1.041;1.005-1.079); cirrhosis with mortality/liver transplantation (11.933;1.984-71.787); and antinuclear antibody (ANA) titers with mortality/liver transplantation (1.001;1.000-1.003), cirrhosis (1.001;1.000-1.002), and autoimmune diseases (1.001; 1.000-1.002). CONCLUSION: In an Asian country endemic for viral hepatitis, the female-to-male and baseline cirrhosis rates of AIH patients were lower than expected, while over 60% of the patients eventually developed cirrhosis. The high posttherapy relapse rate warrants cautious monitoring, particularly for patients with high baseline Alk-p levels. Baseline age, cirrhosis status and ANA titers are crucial for outcomes.

End-to-end interstitial fibrosis assessment of kidney biopsies with a machine learning-based model.

BACKGROUND: The extent of interstitial fibrosis in the kidney not only correlates with renal function at the time of biopsy but also predicts future renal outcome. However, its assessment by pathologists lacks good agreement. The aim of this study is to construct a machine learning-based model that enables automatic and reliable assessment of interstitial fibrosis in human kidney biopsies. METHODS: Validated cortex, glomerulus and tubule segmentation algorithms were incorporated into a single model to assess the extent of interstitial fibrosis. The model performances were compared with expert renal pathologists and correlated with patients' renal functional data. RESULTS: Compared with human raters, the model had the best agreement [intraclass correlation coefficient (ICC) 0.90] to the reference in 50 test cases. The model also had a low mean bias and the narrowest 95% limits of agreement. The model was robust against colour variation on images obtained at different times, through different scanners, or from outside institutions with excellent ICCs of 0.92-0.97. The model showed significantly better test-retest reliability (ICC 0.98) than humans (ICC 0.76-0.94) and the amount of interstitial fibrosis inferred by the model strongly correlated with 405 patients' serum creatinine (r = 0.65-0.67) and estimated glomerular filtration rate (r = -0.74 to -0.76). CONCLUSIONS: This study demonstrated that a trained machine learning-based model can faithfully simulate the whole process of interstitial fibrosis assessment, which traditionally can only be carried out by renal pathologists. Our data suggested that such a model may provide more reliable results, thus enabling precision medicine.

TAFRO Syndrome with Renal Thrombotic Microangiopathy: Insights into the Molecular Mechanism and Treatment Opportunities.

TAFRO syndrome is an extremely rare form of idiopathic MCD, characterized by thrombocytopenia, anasarca, fever, reticulin fibrosis on bone marrow biopsy, and organomegaly. Like idiopathic MCD, renal involvement is also a common presentation in patients with TAFRO syndrome. Furthermore, membranoproliferative glomerulonephritis (MPGN)-like injury and thrombotic microangiopathy (TMA) are the most reported histopathologic findings of renal biopsy. Several molecular mechanisms have been previously postulated in order to explain the TAFRO syndrome symptoms, including abnormal production of interleukin-6 (IL-6), vascular endothelial growth factor (VEGF), etc. The role of these cytokines in renal injury, however, is not well understood. The aim of this review article is to summarize the latest knowledge of molecular mechanisms behind the TAFRO syndrome and their potential role in renal damage.

Vascular endothelial growth factor expression is an independent poor prognostic factor for human epidermal growth factor receptor 2 positive gastric cancer.

BACKGROUND: The positive expression of human epidermal growth factor receptor 2 (HER-2) is phenotypically associated with differentiated gastric cancer (GC) and is a prognostic factor for resectable GC. The aim of this study was to explore the clinical significance of vascular endothelial growth factor (VEGF), protein kinase B, and p38 mitogen-activated protein kinase (MAPK) regarding outcome in patients with HER-2 positive GC, and to analyze the relationship between these molecules and clinicopathologic parameters. MATERIALS AND METHODS: Between January 2001 and December 2012, radical-intent gastrectomy specimens from GC patients were evaluated for HER-2 expression by immunohistochemistry (IHC); and with HER-2 expression levels of 2+ were further subjected to fluorescence in situ hybridization analysis. HER-2 positivity was defined by a HER-2 3+ score on IHC or a HER-2 2+ score on IHC and HER-2 amplification by fluorescence in situ hybridization. The expression of VEGF, phosphorylated protein kinase B, and phosphorylated p38 MAPK in HER-2 positive specimens was scored using IHC. RESULTS: Fifty-four patients with HER-2 positive stage I-III GCs were identified. Univariate analysis of prognostic factors showed that tumor differentiation, the presence of vascular invasion, and overexpression of p-p38 MAPK, and VEGF significantly affected prognosis. Multivariate analysis identified vascular invasion (hazard ratio = 2.704; 95% confidence interval = 1.074-7.088; P < 0.033) and the overexpression of VEGF (hazard ratio = 2.760; 95% confidence interval = 1.083-6.753; P < 0.035) to be independent prognostic predictors of HER-2 positive GC. CONCLUSIONS: VEGF overexpression and the presence of vascular invasion were independent poor prognostic factors for HER-2 positive GCs.

Palliative gastrectomy is beneficial in selected cases of metastatic gastric cancer.

BACKGROUND: Salvage chemotherapy is the mainstay of treatment for metastatic gastric cancer (mGC). This study aimed to clarify the effects of palliative gastrectomy (PG) and identify prognostic factors in mGC patients undergoing PG. METHODS: This was a retrospective review of 333 mGC patients receiving PG or a non-resection procedure (NR) between 2000 and 2010. Clinicopathological factors affecting the prognosis of these patients were collected prospectively and analyzed. RESULTS: One hundred and ninety-three patients underwent PG and 140 NR. The clinicopathological characteristics were comparable between the two groups except for metastatic pattern. There were no significant differences in postoperative morbidity and mortality between the two groups. The PG group had a significantly longer median overall survival compared with the NR group (7.7 months vs. 4.9 months). In the PG group, age ≤58 years, preoperative albumin level >3 g/dL, ratio of metastatic to examined lymph nodes ≤0.58, and administration of chemotherapy were independent prognostic factors in multivariate analysis. CONCLUSIONS: Patients undergoing PG had better outcomes than those undergoing NR. Among the patients undergoing resection, age ≤58 years, a better preoperative nutritional status, less nodal involvement and postoperative chemotherapy independently affected patient survival.

Alterations of the mTOR pathway in hepatic angiomyolipoma with emphasis on the epithelioid variant and loss of heterogeneity of TSC1/TSC2.

AIMS: To determine the significance of the epithelioid type and the corresponding molecular alterations in hepatic angiomyolipoma (AML). METHODS AND RESULTS: We retrieved 24 samples of hepatic AML to delineate the clinicopathological features and the immunohistochemical expression of components in the mTOR pathway, and employed microsatellite markers to analyse allelic imbalances in the TSC1 and TSC2 regions. Myomatous AML was the most common type, and a predominantly epithelioid cell population was observed in 50% of the samples. Two-thirds of all samples contained <20% of fat tissue. Four cases of monotypic epithelioid AML were discovered without prognostic implications. Elevated phospho-p70S6 kinase expression was noted in 19 samples in the absence of phospho-AKT activity. Loss of heterogeneity (LOH) of TSC1/TSC2 was found in 15 samples. As compared wityh syndromic AML samples, sporadic AML samples showed LOH of microsatellite markers to a limited extent. Only four samples had increased ß-catenin expression in the context of concurrent high expression of phospho-p70S6 kinase and phospho-S6 (P = 0.018). CONCLUSIONS: The low fat content and epithelioid cytomorphology in hepatic AML potentially obstruct preoperative and pathological diagnosis. Alteration of the mTOR pathway and LOH of the tuberous sclerosis complex genes is a frequent pathogenesis in hepatic AMLs.

Iatrogenic Kaposi's sarcoma in nasal cavity: a case report.

BACKGROUND: Kaposi's sarcoma (KS) is an uncommon borderline vascular tumor involving mostly the cutaneous and mucosal sites of the body. Among the four distinctly clinicopathological presentations of KS, the iatrogenic form principally occurs in kidney transplant recipients receiving immunosuppressive therapy. It rarely occurs in the head and neck region as primary site or in other groups of patients under immunosuppressive therapy. CASE PRESENTATION: We present of the case of a patient with right nose KS. The patient had history of systemic lupus erythematosus (SLE) and was under immunosuppressive therapy. CONCLUSION: Once we keep KS in mind, the definite diagnosis can be made using routine histological examination and immunohistochemical study despite the rarity of the disease in this site.

A case of renal cell carcinoma metastasizing to invasive ductal breast carcinoma.

Tumor-to-tumor metastasis is an uncommon but well-documented phenomenon. We present a case of a clear cell renal cell carcinoma (RCC) metastasizing to an invasive ductal carcinoma (IDC) of the breast. A 74-year-old woman with a past history of clear cell RCC status after radical nephrectomy underwent right modified radical mastectomy for an enlarging breast mass 3 years after nephrectomy. Histological examination revealed a small focus with distinct morphological features similar to clear cell RCC encased in the otherwise typical IDC. Immunohistochemical studies showed that this focus was positive for CD10 and vimentin, in contrast to the surrounding IDC, which was negative for both markers and positive for Her2/neu. Based on the histological and immunohistochemical features, the patient was diagnosed with metastasis of clear cell RCC to the breast IDC. To the best of our knowledge, this is the first reported case of a breast neoplasm as the recipient tumor in tumor-to-tumor metastasis.

Presentation of glomerulocystic disease in a young onset diabetes: A case report.

RATIONALE: This case report presents a challenging medical scenario involving a young adult male who exhibited an unusual combination of symptoms, including abrupt weight loss, declining renal function, proteinuria, and concurrent onset of diabetes mellitus. Remarkably, the patient had no previous medical history or family history of similar conditions, necessitating a comprehensive investigation. PATIENT CONCERNS: On March 10, 2021, a 25-year-old male sought medical attention due to the aforementioned symptoms. Initial assessments revealed stage 5 chronic kidney disease, with elevated blood urea nitrogen (BUN) and serum creatinine (Cr) levels, as well as significant proteinuria. The only notable physical finding was obesity, and renal ultrasound showed normal-sized kidneys without cysts. DIAGNOSIS: A treatment plan was initiated to stabilize creatinine levels, including medications such as Glimepiride, Glyxambi, Bisoprolol, Amlodipine, and Valsartan. However, despite diligent medication management, proteinuria persisted, prompting further evaluation. A renal biopsy was performed on April 12th, 2023, leading to the diagnosis of glomerulocystic kidney disease with early-stage changes indicative of diabetic nephropathy. INTERVENTIONS: The patient continues to receive ongoing care and follow-up at our outpatient clinic to optimize therapeutic interventions and elucidate the underlying etiology of this complex clinical scenario. OUTCOMES: Ongoing investigations and therapeutic interventions are crucial to understand the underlying cause and optimize patient care in this intricate clinical scenario. LESSONS: This case underscores the complexity of diagnosing and managing a young adult presenting with concurrent renal dysfunction, proteinuria, and diabetes mellitus in the absence of prior underlying conditions. It highlights the importance of comprehensive evaluation and ongoing care in such challenging cases.

Nivolumab-induced acute tubular injury: A case report.

Nivolumab belongs to immune checkpoint inhibitors (ICIs). ICIs-induced kidney injury is rare and acute interstitial nephritis (AIN) is the majority. A 58-year-old woman had gastric cancer treated with nivolumab. Her serum creatinine (Cr) increased to 5.94 mg/dL post 2 cycles of nivolumab and co-administered with acemetacin. A kidney biopsy showed acute tubular injury (ATI). Nivolumab rechallenge was done and Cr worsened again. The lymphocyte transformation test (LTT) indicated a strong positive for nivolumab. Although rare, ATI due to ICIs could not be ruled out, and LTT is a tool to identify the culprit.

Real-World Evidence of Intra-institutional Performance Variation in Indefinite Diagnosis of Pleural Effusion Cytology.

CONTEXT.­: Pleural effusion cytology has been widely used in the investigation of pathologic fluid accumulation in pleural spaces. However, up to one-tenth of the cases were not given a definitive diagnosis. These cases have largely been neglected in the bulk of the literature. OBJECTIVE.­: To provide real-world data on indefinite diagnoses including "atypia of uncertain significance" (AUS) and "suspicious for malignancy" (SFM) in pleural effusion cytology and to investigate pathologists' practice patterns on using these diagnostic categories. DESIGN.­: We reported the diagnoses of 51 675 cases. Descriptive statistics and correlation coefficients were used to analyze the relationships between different diagnostic categories and pathologists' practice patterns and possible explanatory variables. RESULTS.­: The diagnoses AUS and SFM were reported in 4060 cases (7.86%) and 1554 cases (3.01%) in the cohort, respectively. The mean rates for these indefinite diagnoses varied up to 3-fold between pathologists. Correlations were found between AUS and SFM, as well as between indefinite diagnoses and negative for malignancy (NFM). No correlations were found between pathologists' years of experience or case volume and the rates of indefinite diagnosis or diagnostic certainty. CONCLUSIONS.­: A real-world baseline for the rates of indefinite diagnoses in pleural effusion cytology is provided in this large retrospective study. Pathologists show significant variation in their use of indefinite diagnostic categories, and the tendency to use these ambiguous terms was not correlated with individuals' experience or case volume. How to untangle the intertwined relationship between the uncertainty of indefinite diagnoses and that of NFM requires future prospective studies.

Bevacizumab-Induced Thrombotic Microangiopathy (TMA) in Metastatic Lung Adenocarcinoma Patients Receiving Nivolumab Combined with Bevacizumab, Carboplatin and Paclitaxel: Two Case Reports.

Anti-programmed death-1 (PD-1)/programmed death ligand 1 (PD-L1) immune checkpoint inhibitors (ICIs), combined with bevacizumab and platinum-based chemotherapy, have shown promising efficacy in treating metastatic non-squamous cell lung cancer in phase 3 clinical trials. However, drug-induced nephrotoxicity is an uncommon but threatening adverse effect when using this combination therapy, and should be evaluated and managed carefully. Here, we present two patients experiencing late-onset asymptomatic heavy proteinuria during the clinical trial. Kidney biopsies performed finally identified bevacizumab-induced thrombotic microangiopathy (TMA), and the proteinuria was decreased after discontinuing bevacizumab permanently. Our report suggests that a kidney biopsy is needed for those receiving ICIs in combination with bevacizumab and chemotherapy and experiencing nephrotoxicity such as heavy proteinuria.

The pathological spectrum of pediatric kidney disease: 18-Year experience from a single tertiary care center in northern Taiwan.

BACKGROUND: Glomerular disease is one of the leading causes of chronic kidney disease in children worldwide. Recent studies outlined the changing spectrum of glomerular disease in certain countries. Therefore, our study aimed to evaluate the histopathological patterns and changes in pediatric kidney disease over the past 18 years in northern Taiwan. METHODS: This was a retrospective chart review study of pediatric patients (≤18 years of age) undergoing percutaneous renal biopsies (PRBs) of native kidneys between January 2002 and July 2020 from a Pediatric Care Center at Chang Gung Memorial Hospital, Taoyuan, Taiwan. RESULTS: This study analyzed a total of 339 pediatric native PRBs. The mean age of the subjects was 13.7 ± 7.0 years (184 girls and 155 boys). The most common indications of PRBs included acute nephritic syndrome (55.7%), idiopathic nephrotic syndrome (22.7%), persistent asymptomatic hematuria (13.9%), and unexplained renal failure (7.7%). Our study revealed that proliferative lupus nephritis (LN), minimal change disease (MCD)-related nephrotic syndrome, and IgA nephropathy (IgAN) were the most frequent biopsy-proven pediatric glomerular diseases. In addition, we showed that severe acute post-streptococcal glomerulonephritis (APSGN) was infrequent and has not even been diagnosed since 2010. CONCLUSION: Our result revealed that the spectrum of biopsy-proven pediatric kidney disease has not changed significantly over the past two decades. Furthermore, proliferative LN, MCD, and primary IgAN continue to be the most common histopathological diagnoses among Taiwanese children.

Learning more from the inter-rater reliability of interstitial fibrosis assessment beyond just a statistic.

Interstitial fibrosis assessment by renal pathologists lacks good agreement, and we aimed to investigate its hidden properties and infer possible clinical impact. Fifty kidney biopsies were assessed by 9 renal pathologists and evaluated by intraclass correlation coefficients (ICCs) and kappa statistics. Probabilities of pathologists' assessments that would deviate far from true values were derived from quadratic regression and multilayer perceptron nonlinear regression. Likely causes of variation in interstitial fibrosis assessment were investigated. Possible misclassification rates were inferred on reported large cohorts. We found inter-rater reliabilities ranged from poor to good (ICCs 0.48 to 0.90), and pathologists' assessments had the worst agreements when the extent of interstitial fibrosis was moderate. 33.5% of pathologists' assessments were expected to deviate far from the true values. Variation in interstitial fibrosis assessment was found to be correlated with variation in interstitial inflammation assessment (r2 = 32.1%). Taking IgA nephropathy as an example, the Oxford T scores for interstitial fibrosis were expected to be misclassified in 21.9% of patients. This study demonstrated the complexity of the inter-rater reliability of interstitial fibrosis assessment, and our proposed approaches discovered previously unknown properties in pathologists' practice and inferred a possible clinical impact on patients.

Unsatisfactory reproducibility of interstitial inflammation scoring in allograft kidney biopsy.

Interstitial inflammation scoring is incorporated into the Banff Classification of Renal Allograft Pathology and is essential for the diagnosis of T-cell mediated rejection. However, its reproducibility, including inter-rater and intra-rater reliabilities, has not been carefully investigated. In this study, eight renal pathologists from different hospitals independently scored 45 kidney allograft biopsies with varying extents of interstitial inflammation. Inter-rater reliabilities and intra-rater reliabilities were investigated by kappa statistics and conditional agreement probabilities. Individual pathologists' scoring patterns were examined by chi-squared tests and proportions tests. The mean pairwise kappa values for inter-rater reliability were 0.27, 0.30, and 0.26 for the Banff i score, ti score, and i-IFTA, respectively. No rater pair performed consistently better or worse than others on all three scorings. After dichotomizing the scores into two groups (none/mild and moderate/severe inflammation), the averaged conditional agreements ranged from 47.1% to 50.0%. The distributions of the scores differed, but some pathologists persistently scored higher or lower than others. Given the important role of interstitial inflammation scoring in the diagnosis of T-cell mediated rejection, transplant practitioners should be aware of the possible clinical implications of the far-from-optimal reproducibility.

Adenoid basal carcinoma of the uterine cervix: clinicopathologic features of 12 cases with reference to CD117 expression.

Adenoid basal carcinoma is a rare tumor of the uterine cervix. Less than 100 cases have been documented thus far, and only a few cases have been reported among the Asian population. An important differential diagnosis is cervical adenoid cystic carcinoma because of their overlapping morphologic appearances but absolutely different clinical outcomes. The treatment of adenoid basal carcinoma should be conservative due to its generally benign behavior. CD117 (c-kit) have been recently found immunohistochemically positive for adenoid cystic carcinomas of other anatomic locations and may serve as a useful ancillary differential marker. CD117 expression for adenoid cystic carcinoma and adenoid basal carcinoma of the uterine cervix has never been evaluated. We report the clinicopathologic features of 12 adenoid basal carcinomas with reference to CD117 expression, which represent the largest series from the Asian population. All typical adenoid basal carcinomas are negative for CD117 or have only an equivocal staining intensity. In contrast, 1 adenoid cystic carcinoma and 1 mixed adenoid basal/cystic carcinoma of the uterine cervix are positive for CD117. CD117 may be of value in differential diagnosis between these 2 entities and guide follow-up and treatment program. Further investigation of CD117 expression in a larger series of adenoid cystic carcinoma of the uterine cervix is needed to validate this notion.

Association between breast cancer and hepatitis C: A joint study of hospitalized patients and nationwide cohorts.

Whether hepatitis C virus (HCV) infection is associated with breast cancer risk remains elusive, and we aimed to elucidate it. A nationwide population-based cohort study of the Taiwan National Health Insurance Research Database (TNHIRD) was conducted. Additionally, breast cancer risk factors, and HCV core expression were surveyed in breast cancer patients of a tertiary care center. Three TNHIRD cohorts (1:4:4, propensity score-matched, 2003-2012), including HCV-treated (3646 HCV-infected females with interferon-based therapy ≥6 months), HCV-untreated (n = 14,584) and HCV-uninfected (n = 14,584) cohorts, were enrolled. The HCV-untreated cohort had the highest 9-year breast cancer cumulative incidence (2.017%; 95% confidence interval [CI]: 1.382%-2.846%), while the HCV-treated (1.073%; 0.414%-2.356%), and HCV-uninfected (1.453%; 0.785%-2.486%) cohorts showed no difference. Untreated HCV infection (hazard ratio [HR]: 1.701; 95% CI: 1.205%-2.400), urban residency (1.658, 1.183-2.323), and baseline cardiovascular events (1.920; 1.005-3.668) were associated with incident breast cancers. The interaction analysis showed that particularly among patients <49 years, HCV infection was associated with breast cancer development (2.193; 1.097-4.384). Of 12,170 hospitalized breast cancer patients, 4.90% were HCV Ab-positive. HCV Ab-positive patients were older (60.92+/-10.82 vs 53.91+/-11.38 years, P < 0.0001) and had a higher body mass index (25.39+/-5.1 vs 24.5+/-4.3 kg/m2, P = 0.007), rates of diabetes (30.60 vs 19.98%, P < 0.0001), hypertension (46.9 vs 30.39%, P < 0.0001), dyslipidemia (25.52 vs 20.28%, P = 0.031), and hyperuricemia (11.38 vs 5.52%, P < 0.0001) than their counterparts. No HCV core-positive cells were demonstrated in breast cancer tissues. Conclusions: Untreated HCV infection, urbanization, and cardiovascular events were potential risk factors for breast cancer. The HCV-associated risk was most prominent among patients <49 years, might not be associated with in situ HCV core-related oncogenesis but with metabolic alterations, and was reversed by anti-HCV therapy.

Glomerular disease classification and lesion identification by machine learning.

BACKGROUND: Classification of glomerular diseases and identification of glomerular lesions require careful morphological examination by experienced nephropathologists, which is labor-intensive, time-consuming, and prone to interobserver variability. In this regard, recent advance in machine learning-based image analysis is promising. METHODS: We combined Mask Region-based Convolutional Neural Networks (Mask R-CNN) with an additional classification step to build a glomerulus detection model using human kidney biopsy samples. A Long Short-Term Memory (LSTM) recurrent neural network was applied for glomerular disease classification, and another two-stage model using ResNeXt-101 was constructed for glomerular lesion identification in cases of lupus nephritis. RESULTS: The detection model showed state-of-the-art performance on variedly stained slides with F1 scores up to 0.944. The disease classification model showed good accuracies up to 0.940 on recognizing different glomerular diseases based on H&E whole slide images. The lesion identification model demonstrated high discriminating power with area under the receiver operating characteristic curve up to 0.947 for various glomerular lesions. Models showed good generalization on external testing datasets. CONCLUSION: This study is the first-of-its-kind showing how each step of kidney biopsy interpretation carried out by nephropathologists can be captured and simulated by machine learning models. The models were integrated into a whole slide image viewing and annotating platform to enable nephropathologists to review, correct, and confirm the inference results. Further improvement on model performances and incorporating inputs from immunofluorescence, electron microscopy, and clinical data might realize actual clinical use.

Combination Biomarker of Immune Checkpoints Predict Prognosis of Urothelial Carcinoma.

In contrast to Western counties, the incidence of urothelial carcinoma (UC) remains mar-edly elevated in Taiwan. Regulatory T cells (Tregs) play a crucial role in limiting immune responses within the tumor microenvironment. To elucidate the relationship between immune checkpoints in the tumor immune microenvironment and UC progression, we utilize the Gene Expression Omnibus (GEO) to analyze a microarray obtained from 308 patients with UC. We observed that the expression level of CD276 or TIM-3 was positively correlated with late-stage UC and poor prognosis. Patients with simultaneously high CD276 and TIM-3 expression in tumors have significantly reduced both univariate and multivariate survival, indicating that mRNA levels of these immune checkpoints could be independent prognostic biomarkers for UC overall survival and recurrence. Our cohort study showed rare CD8+ cytotoxic T-cells and Tregs infiltration during early-stage UC-known as cold tumors. Approximately 30% of late-stage tumors exhibited highly infiltrated cytotoxic T cells with high PD-1 and FOXP3 expression, which implied that cytotoxic T cells were inhibited in the advanced UC microenvironment. Collectively, our findings provide a better prognosis prediction by combined immune checkpoint biomarkers and a basis for early-stage UC standard treatment to convert cold tumors into hot tumors, followed by immune checkpoint therapy.