Analysis of IgG subclass staining for IgG immunofluorescence-positive IgA nephropathy.

AIMS: The clinicopathological significance of IgG subclass staining is unclear in IgG immunofluorescence (IF)-positive IgA nephropathy (IgAN). This study investigated IgG subclass distribution in IgG IF-positive IgAN by IF staining and examined their clinicopathological significance. MATERIALS AND METHODS: From January 2015 to December 2020, 27 biopsies from 26 patients with IgG IF-positive IgAN who were IF-positive for any IgG subclass staining were collected. We compared the clinicopathological findings between cases with and without IF positivity for each IgG subclass. RESULTS: Of the 27 biopsies with IgG IF-positive IgAN, 20 (74.1%) were IF-positive for IgG1, 10 (37.0%) were positive for IgG2, 7 (25.9%) were positive for IgG3, and none were positive for IgG4. Oxford E and C scores were significantly higher in cases of IgG IF-positive IgAN than IgG IF-negative IgAN. The age at biopsy had a negative correlation with IgG1 IF intensity (γ = -0.604, p = 0.001). The levels of proteinuria and microscopic hematuria as well as Oxford classification score were not significantly different between cases with or without positive staining for each IgG subclass. IgG IF intensity had a positive correlation with IgG1 IF intensity (γ = 0.741, p < 0.001). CONCLUSION: IgG1-positive IF staining intensity was highest among each IgG subclass in IgG IF-positive IgAN biopsies. A negative correlation was revealed between the age at biopsy and IgG1 IF intensity. Oxford E and C scores were higher in patients with IgG IF-positive IgAN than in those with IgG IF-negative IgAN. The Oxford score was not significantly different between the IgG subclasses, but the IF intensity of IgG had a positive correlation with the IF intensity of IgG1 in IgG IF-positive IgAN biopsies. Further studies should assess relationships between IgG subclass IF deposition and examine the pathogenesis of IgAN.

Clinicopathological importance of Bcl-2 and p53 in postmenopausal triple-negative breast carcinoma and association with age.

Appropriate biomarkers are required to predict the clinical outcome of triple-negative breast cancer (TNBC). In this study, we focused on the clinical importance of two representative tumor-associated proteins, Bcl-2 and p53. Bcl-2 expression is usually related to estrogen receptor expression and a favorable outcome in breast cancer. TNBC has been reported to show a high frequency of p53 positivity suggesting TP53 mutations. The expressions of Bcl-2 and p53 were immunohistochemically examined in TNBC involving two age groups of postmenopausal women (≥75 y/o, n = 75; 55-64 y/o, n = 47), who underwent surgery without neoadjuvant therapy. We examined their associations with each other, or with clinicopathological factors including the outcome. Bcl-2 expression was inversely correlated with androgen receptor, apocrine morphology, and p53 expressions, and was an independent predictor of a poor outcome in total or in younger women. p53 positivity was associated with a more favorable outcome than p53 negativity in the younger group. In combined analyzes, none of the twenty Bcl-2-negative/p53-positive cases in the younger group exhibited recurrence, resulting in the independent favorable predictive value of Bcl-2-negative/p53-positive. The anti-apoptotic nature of Bcl-2 may be apparent in TNBC. The excellent outcome of Bcl-2-negative/p53-positive cases in the younger group warrants further combined investigation of Bcl-2/p53 in TNBC.

Hepatitis B Virus-related Membranous Nephropathy with Crescentic Formation in an Inactive Carrier of Positive Hepatitis B Surface Antigen with Undetectable DNA under Anti-viral Treatment.

A man who was an inactive hepatitis B virus (HBV) carrier with positive hepatitis B surface antigen (HBs antigen) and undetectable HBV-DNA under anti-viral treatment developed nephrotic syndrome at 52 years old, and a renal biopsy revealed advanced membranous nephropathy (MN) with focal cellular crescents, interstitial hemorrhaging, and peritubular capillaritis. Immunofluorescence studies demonstrated granular IgG deposition and HBs antigen-positivity along the capillaries. Glomeruli were negative for phospholipase A2 receptor 1. There were no clinical findings of systemic vasculitis. We considered MN combined with small-vessel vasculitis due to HBV infection. These results suggest that HBV-related kidney disease should be considered even in patients with an inactive HBV carrier status under treatment.

Fibroblast growth factor 18 stimulates the proliferation of hepatic stellate cells, thereby inducing liver fibrosis.

Liver fibrosis results from chronic liver injury triggered by factors such as viral infection, excess alcohol intake, and lipid accumulation. However, the mechanisms underlying liver fibrosis are not fully understood. Here, we demonstrate that the expression of fibroblast growth factor 18 (Fgf18) is elevated in mouse livers following the induction of chronic liver fibrosis models. Deletion of Fgf18 in hepatocytes attenuates liver fibrosis; conversely, overexpression of Fgf18 promotes liver fibrosis. Single-cell RNA sequencing reveals that overexpression of Fgf18 in hepatocytes results in an increase in the number of Lrat+ hepatic stellate cells (HSCs), thereby inducing fibrosis. Mechanistically, FGF18 stimulates the proliferation of HSCs by inducing the expression of Ccnd1. Moreover, the expression of FGF18 is correlated with the expression of profibrotic genes, such as COL1A1 and ACTA2, in human liver biopsy samples. Thus, FGF18 promotes liver fibrosis and could serve as a therapeutic target to treat liver fibrosis.

Irradiation Attenuates Systemic Lupus Erythematosus-Like Morbidity in NZBWF1 Mice: Focusing on CD180-Negative Cells.

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterized by the production of autoantibodies that can induce systemic inflammation. Ultraviolet-A and X-ray irradiation have been reported to have therapeutic effects in patients with SLE. We previously demonstrated that CD180-negative cells, these are radiosensitive, contribute to the development of SLE-like morbidity in NZBWF1 mice. In this study, the effects of irradiation on SLE-like morbidity manifestations in NZBWF1 mice and on CD180-negative cells were investigated. Whole-body irradiation, excluding the head, attenuated SLE-like morbidity in vivo, as indicated by the prevention of the renal lesion development, inhibition of anti-dsDNA antibody production, reduction of urinary protein levels, and prolongation of the lifespan. Irradiation also reduced the proportion of CD180-negative cells in the spleen. Although other immune cells or molecules may be triggered because of the whole-body irradiation treatment, previous research, and the current results suggest a strong relationship between the radiation-induced decrease in CD180-negative cells and the amelioration of SLE-like morbidities. Clinical trials assessing CD180-negative cells as a therapeutic target for SLE have been hampered by the lack of validated cell markers; nonetheless, the present findings suggest that radiotherapy may be a new therapeutic strategy for managing SLE symptoms.

Mesangiolysis in Pathological Chronic Active Antibody-Mediated Rejection in Kidney Transplant Biopsies.

INTRODUCTION: This study aimed to determine if immune or nonimmune and acute or chronic lesions associated with mesangiolysis (MGLS) occurred in biopsy-proven pathological chronic active antibody-mediated rejection (P-CAABMR) in kidney transplant biopsies. METHODS: We evaluated MGLS in 41 patients with biopsy findings of P-CAABMR from January 2016 to December 2019. Histological scoring was evaluated by Banff classification. Multivariate logistic regression analysis was performed using a forward selection method. RESULTS: Fifteen of the 41 P-CAABMR biopsies (36.6%) cases showed MGLS. The estimated glomerular filtration rate (eGFR) was significantly lower in the MGLS-positive compared with the MGLS-negative group, and proteinuria was significantly higher in the MGLS-positive compared with the MGLS-negative group. In the clinical model, multivariate analysis was performed using covariates of eGFR and duration after transplantation significantly correlated with MGLS by simple analysis, in addition to type of calcineurin inhibitor use (tacrolimus or cyclosporine), donor-specific antibodies, diabetes, and hypertension grade defined by use of antihypertensive therapy or/and blood pressure level. Only hypertension grade was significantly correlated with MGLS. In the pathological model, multivariate analysis was performed using the presence of FSGS and the aah and cg scores significantly correlated with MGLS by simple analysis, in addition to g and ptc scores. The cg score was significantly correlated with hypertension grade, duration after transplantation, g, ah, and aah. CONCLUSION: Lower graft function and higher proteinuria was observed in MGLS of P-CAABMR. The Banff cg score was independently related to MGLS in multivariate analysis. Sustained glomerulitis, calcineurin inhibitor nephrotoxicity, and hypertension may cause Banff cg lesions, leading to MGLS in P-CAABMR.

Corrigendum: Senescence of alveolar epithelial cells impacts initiation and chronic phases of murine fibrosing interstitial lung disease.

[This corrects the article DOI: 10.3389/fimmu.2022.935114.].

Vesicoureteral Reflux Causes Interstitial Inflammation in Pediatric Kidney Allograft: A Clinicopathological Analysis of 1-Year Protocol Biopsies.

INTRODUCTION: At present, there is limited evidence of the histological impact of vesicoureteral reflux (VUR) on pediatric kidney allografts. In this study, we aimed to investigate the relationship between VUR diagnosed by voiding cystourethrography (VCUG) and 1-year protocol biopsy results. METHODS: One hundred thirty-eight pediatric kidney transplantations were performed in Toho University Omori Medical Center between 2009 and 2019. We included 87 pediatric transplant recipients who were evaluated for VUR by VCUG prior to or at the time of the 1-year protocol biopsy and underwent a 1-year protocol biopsy after transplantation. We evaluated the clinicopathological findings of the VUR and non-VUR groups, and histological scores were evaluated using the Banff score. Tamm-Horsfall protein (THP) within the interstitium was identified by light microscopy. RESULTS: Of the 87 transplant recipients, 18 cases (20.7%) were diagnosed with VUR by VCUG. The clinical background and findings were not significantly different between the VUR and non-VUR groups. The pathological findings revealed a significantly higher Banff total interstitial inflammation (ti) score in the VUR group than in the non-VUR group. Multivariate analysis indicated a significant relationship between the Banff ti score and THP within the interstitium, and VUR. The 3-year protocol biopsy results (n = 68) revealed a significantly higher Banff interstitial fibrosis (ci) score in the VUR group than in the non-VUR group. CONCLUSION: VUR caused interstitial fibrosis in the 1-year pediatric protocol biopsies, and interstitial inflammation at the 1-year protocol biopsy may affect interstitial fibrosis at the 3-year protocol biopsy.

Prognostic value of the 7-year protocol biopsy of adult kidney allografts: impact of mesangiosclerosis and proteinuria.

AIM: The aim of the present study was to clarify the relationship between the Banff score of the 7-year protocol biopsy and the allograft outcome. METHODS: One-hundred-and-eighty-four patients received kidney transplantation from 2002 to 2008. We excluded patients aged <20 years at transplantation (n = 24), those who did not undergo a 7-year protocol biopsy (n = 66), and those who underwent for-cause biopsy (n = 5). Consequently, 89 patients who underwent a 7-year protocol biopsy were enrolled. We analyzed the relationship between the clinicopathological findings 7 years after transplantation and the estimated glomerular filtration rate (eGFR) change per year and allograft survival. Histological evaluation was performed using the Banff 2015 classification. RESULTS: Among the clinicopathological findings, each Banff mesangial matrix increase (mm) score ≥1 and proteinuria ≥1+ was independently associated with the eGFR decline per year during a median follow-up of 73 months. Furthermore, in the model of the clinicopathological findings including the presence of mm with proteinuria, mm ≥1 alone and mm ≥1 with proteinuria were each independently associated with the eGFR decline. The graft survival was significantly worse for those with mm ≥1 with proteinuria than those with mm ≥1 without proteinuria. CONCLUSION: Among the 7-year protocol biopsy findings, the presence of mm alone and mm with proteinuria were each significant predictors of eGFR decline. The presence of both proteinuria and mm had a negative impact on graft survival. These results underscore the significance of the Banff mm score and proteinuria at the time of the 7-year protocol biopsy to predict the allograft outcome.

Subclinical C1q Nephropathy Combined with Possible Donor-Derived IgA Deposition in a 1-Year Kidney Allograft Biopsy: A Case Report.

Few previous studies have reported immune-complex nephropathy that has not been classified as a specific phenotype in kidney allografts. We report a case of a de novo subclinical "full-house" pattern of deposition in a pediatric transplantation recipient with possible donor-derived IgA deposition. A five-year-old boy underwent living kidney transplantation due to congenital kidney and urinary tract anomalies. A one-hour implantation biopsy revealed IgA deposition. A four-month protocol biopsy finding showed less intense IgA deposition, in contrast with the one-hour biopsy, and trace para-mesangial deposits. A one-year protocol biopsy demonstrated a full-house deposition pattern and massive electron-dense deposits with minor glomerular changes. At the time of the one-year biopsy, kidney function was stable, with no urinalysis abnormalities. No evidence of systemic lupus erythematosus was observed in clinical and serologic examinations. Mesangial IgG, IgM, C3, and C1q deposition was codominant, and IgA deposition was weaker. We diagnosed this case as C1q nephropathy combined with remaining donor-derived IgA deposition. Few studies have reported C1q nephropathy in kidney allograft; further accumulation of cases is required. To distinguish between donor-derived and de novo glomerular lesions, it is important to assess the serial histologic findings of immunofluorescence and electron microscopy. Here, we report a rare case of subclinical C1q nephropathy with possible donor-derived IgA nephropathy.

Estrogen Receptor-ß Gene Cytosine-Adenine (ESR2-CA) Repeat Polymorphism in Postmenopausal Colon Cancer.

The pathobiological role of estrogen is controversial in colorectal cancer. Cytosine-adenine (CA) repeat in the estrogen receptor (ER)-ß gene (ESR2-CA) is a microsatellite, as well as representative of ESR2 polymorphism. Though its function is unknown, we previously showed that a shorter allele (germline) increased the risk of colon cancer in older women, whereas it decreased it in younger postmenopausal women. ESR2-CA and ER-ß expressions were examined in cancerous (Ca) and non-cancerous (NonCa) tissue pairs from 114 postmenopausal women, and comparisons were made considering tissue types, age/locus, and the mismatch repair protein (MMR) status. ESR2-CA repeats <22/≥22 were designated as 'S'/'L', respectively, resulting in genotypes SS/nSS (=SL&LL). In NonCa, the rate of the SS genotype and ER-ß expression level were significantly higher in right-sided cases of women ≥70 (≥70Rt) than in those in the others. A decreased ER-ß expression in Ca compared with NonCa was observed in proficient-MMR, but not in deficient-MMR. In NonCa, but not in Ca, ER-ß expression was significantly higher in SS than in nSS. ≥70Rt cases were characterized by NonCa with a high rate of SS genotype or high ER-ß expression. The germline ESR2-CA genotype and resulting ER-ß expression were considered to affect the clinical characteristics (age/locus/MMR status) of colon cancer, supporting our previous findings.

Significance of Multinucleated Polyploidization of Tubular Epithelial Cells in Kidney Allografts.

INTRODUCTION: Multinucleated polyploidization (MNP) of tubular epithelial cells is occasionally observed in kidney allografts. The present study aimed to clarify the clinical and pathological significance of MNP of tubular epithelial cells in kidney allografts. METHODS: Fifty-eight 1-year biopsies from 58 patients who underwent kidney transplantation at our hospital from January 2016 to December 2017 were included. MNP was counted in each specimen, and the specimens were divided into two groups by the median value. The differences in clinical and pathological characteristics were compared. Ki67-positive cells were counted among tubular epithelial cells to explore the association between cell cycle and MNP. In an additional cohort, MNP was compared between biopsies after precedent T-cell-mediated rejection and precedent medullary ray injury. RESULTS: The 58 cases were divided into two groups by the median total amount of MNP: group A (MNP > 3) and group B (MNP ≤ 3). Maximum t-score before the 1-year biopsy was significantly higher in group A compared with group B. Other clinical or histological characteristics did not differ significantly. Total amount of Ki67-positive tubular epithelial cells was significantly correlated with total amount of MNP. Significantly higher amount of MNP was observed in cases with precedent T-cell-mediated rejection compared with precedent medullary ray injury. On receiver operating characteristic curve analysis, the cut-off value of MNP to predict precedent T-cell-mediated rejection was 8.5. CONCLUSIONS: MNP in tubular epithelial cells reflects prior tubular inflammation in kidney allografts. High amount of MNP indicates precedent T-cell-mediated rejection rather than precedent medullary ray injury caused by nonimmune etiologies.

Estrogen receptor beta expression in colitis-associated carcinoma in comparison with sporadic colonic tumor: An immunohistochemical study.

Background and Aim: The rate of ulcerative colitis (UC)-related colorectal cancer (colitis-associated carcinoma) is increasing. Estrogen receptor (ER) beta expression has been studied separately in patients with sporadic colorectal cancer and those with colitis-associated carcinoma. However, no study has compared the expression in both of these cancer types. The present study aimed to evaluate the relationship between colitis-associated carcinoma and ERs and assess whether the expression of ER beta influences cell proliferation. Methods: This study included 45 surgically operated colitis-associated carcinomas, 43 high-grade dysplasias, 34 low-grade dysplasias, 36 sporadic colorectal cancers, 44 high-grade adenomas, and 34 low-grade adenomas. ER beta expression was evaluated with immunohistochemistry. Results: Colitis-associated carcinoma showed significantly lower ER beta immunoexpression than sporadic colorectal lesions and high- and low-grade dysplasia. In seven colitis-associated carcinoma harboring both intensity score 3 (strong immunoexpression) and score 1 (weak immunoexpression) areas, the correlation among ER beta intensity, Ki-67, and p21 labeling index was assessed; an area with an ER beta intensity score of 3 showed a higher Ki-67 labeling index than that with score 1. In four out of the seven lesions, p21 labeling index was higher in the area of ER beta score 1 than in that of ER beta score 3. Conclusions: The data suggest that ER beta expression is an accelerating factor in colorectal tumors. This association may be lower in colitis-associated carcinoma than in sporadic colorectal cancer.

Interleukin 11 confers resistance to dextran sulfate sodium-induced colitis in mice.

Intestinal homeostasis is tightly regulated by epithelial cells, leukocytes, and stromal cells, and its dysregulation is associated with inflammatory bowel diseases. Interleukin (IL)-11, a member of the IL-6 family of cytokines, is produced by inflammatory fibroblasts during acute colitis. However, the role of IL-11 in the development of colitis is still unclear. Herein, we showed that IL-11 ameliorated DSS-induced acute colitis in mouse models. We found that deletion of Il11ra1 or Il11 rendered mice highly susceptible to DSS-induced colitis compared to the respective control mice. The number of apoptotic epithelial cells was increased in DSS-treated Il11ra1- or Il11-deficient mice. Moreover, we showed that IL-11 production was regulated by reactive oxygen species (ROS) produced by lysozyme M-positive myeloid cells. These findings indicate that fibroblast-produced IL-11 plays an important role in protecting the mucosal epithelium in acute colitis. Myeloid cell-derived ROS contribute to the attenuation of colitis through the production of IL-11.

Generation of transgenic mice expressing a FRET biosensor, SMART, that responds to necroptosis.

Necroptosis is a regulated form of cell death involved in various pathological conditions, including ischemic reperfusion injuries, virus infections, and drug-induced tissue injuries. However, it is not fully understood when and where necroptosis occurs in vivo. We previously generated a Forster resonance energy transfer (FRET) biosensor, termed SMART (the sensor for MLKL activation by RIPK3 based on FRET), which monitors conformational changes of MLKL along with progression of necroptosis in human and murine cell lines in vitro. Here, we generate transgenic (Tg) mice that express the SMART biosensor in various tissues. The FRET ratio is increased in necroptosis, but not apoptosis or pyroptosis, in primary cells. Moreover, the FRET signals are elevated in renal tubular cells of cisplatin-treated SMART Tg mice compared to untreated SMART Tg mice. Together, SMART Tg mice may provide a valuable tool for monitoring necroptosis in different types of cells in vitro and in vivo.

Senescence of alveolar epithelial cells impacts initiation and chronic phases of murine fibrosing interstitial lung disease.

Fibrosing interstitial lung disease (ILD) develops due to the impaired reparative processes following lung tissue damage. Cellular senescence has been reported to contribute to the progression of fibrosis. However, the mechanisms by which these senescent cells initiate and/or drive the progression of lung tissue fibrosis are not yet fully understood. We demonstrated that p21WAF1/CIP1- and p16INK4A-pathway-dependent senescence in type 2 alveolar epithelial cells (AEC2) were both involved in the initiation and progression of lung fibrosis in murine bleomycin (BLM)-induced ILD. p21WAF1/CIP1-senescent AEC2 emerged rapidly, as early as 1 day after the intratracheal instillation of BLM. Their number subsequently increased and persisted until the later fibrosis phase. Very few p16INK4A-senescent AEC2 emerged upon the instillation of BLM, and their increase was slower and milder than that of p21WAF1/CIP1+ AEC2. AEC2 enriched with senescent cells sorted from BLM-ILD lungs expressed senescence-associated secretory phenotype (SASP)-related genes, including Il6, Serpin1, Tnfa, Ccl2, Tgfb, and Pdgfa, at the initiation and chronic phases of fibrosis, exhibiting distinct expression patterns of magnitude that were dependent on the disease phase. Ly6C+ inflammatory monocytes increased in the lungs immediately after the instillation of BLM and interstitial macrophages increased from day 3. The expression of Acta2 and Col1a1 was upregulated as early as day 1, indicating the activation of fibroblasts. We speculated that IL-6, plasminogen activator inhibitor-1 (PAI-1), and TGF-ß contributed to the accumulation of senescent cells during the progression of fibrosis in an autocrine and paracrine manner. In addition, CCL2, produced in large amounts by senescent AEC2, may have induced the infiltration of Ly6C+ inflammatory monocytes in the early phase, and TGF-ß and PDGFa from senescent AEC2 may contribute to the activation of fibroblasts in the very early phases. Our study indicated that senescent AEC2 plays a role in the pathogenesis of fibrosing ILD throughout the course of the disease and provides insights into its pathogenesis, which may lead to the development of new therapeutic methods targeting senescent cells or SASP molecules.

IκBζ controls IL-17-triggered gene expression program in intestinal epithelial cells that restricts colonization of SFB and prevents Th17-associated pathologies.

Control of gut microbes is crucial for not only local defense in the intestine but also proper systemic immune responses. Although intestinal epithelial cells (IECs) play important roles in cytokine-mediated control of enterobacteria, the underlying mechanisms are not fully understood. Here we show that deletion of IκBζ in IECs in mice leads to dysbiosis with marked expansion of segmented filamentous bacteria (SFB), thereby enhancing Th17 cell development and exacerbating inflammatory diseases. Mechanistically, the IκBζ deficiency results in decrease in the number of Paneth cells and impairment in expression of IL-17-inducible genes involved in IgA production. The decrease in Paneth cells is caused by aberrant activation of IFN-γ signaling and a failure of IL-17-dependent recovery from IFN-γ-induced damage. Thus, the IL-17R-IκBζ axis in IECs contributes to the maintenance of intestinal homeostasis by serving as a key component in a regulatory loop between the gut microbiota and immune cells.

Outcome of ABO-incompatible kidney transplantation using a modified desensitization protocol without plasmapheresis.

OBJECTIVES: Several controversies regarding desensitization strategies for successful ABO-incompatible (ABOi) kidney transplantation still exist. This study aimed to investigate whether pretransplant anti-A/B antibody removal is mandatory in an ABOi kidney transplant recipient with low baseline isoagglutinin titers. METHODS: We adopted a modified desensitization protocol with two doses of rituximab (RTX, 100 mg/body) without pretransplant antibody removal for ABOi kidney transplant recipients with a titer of ≤1:64 (group A; n = 35) and investigated the feasibility of this protocol by comparing it with the clinical outcomes of patients undergoing standard pretransplant plasmapheresis (group B; n = 21). RESULTS: There was no significant difference in the rate of antibody-mediated rejection within the first month after transplantation between the two groups (11.4% in group A vs. 2% in group B, p = 0.6019). Moreover, no differences were observed in the short- and long-term graft outcomes between the groups. However, two major critical acute antibody-mediated events occurred in group A; one patient lost the graft due to hyperacute rejection, and the other patient developed thrombotic microangiopathy after surgery. Risk factors predicting these perioperative complications were not identified. CONCLUSIONS: We conclude that not only B-cell depletion using RTX but also pretransplant antibody removal is still recommended even for patients with low isoagglutinin titers. In addition, a new diagnostic tool is needed for accurate risk stratification.

Machine learning-based gene alteration prediction model for primary lung cancer using cytologic images.

BACKGROUND: Understanding the gene alteration status of primary lung cancers is important for determining treatment strategies, but gene testing is both time-consuming and costly, limiting its application in clinical practice. Here, potential therapeutic targets were selected by predicting gene alterations in cytologic specimens before conventional gene testing. METHODS: This was a retrospective study to develop a cytologic image-based gene alteration prediction model for primary lung cancer. Photomicroscopic images of cytology samples were collected and image patches were generated for analyses. Cancer-positive (n = 106) and cancer-negative (n = 32) samples were used to develop a neural network model for selecting cancer-positive images. Cancer-positive cases were randomly assigned to training (n = 77) and validation (n = 26) data sets. Another neural network model was developed to classify cancer images of the training data set into 4 groups: anaplastic lymphoma kinase (ALK)-fusion, epidermal growth factor receptor (EGFR), or Kirsten rat sarcoma viral oncogene homologue (KRAS) mutated groups, and other (None group), and images of the validation data set were classified. A decision algorithm to predict gene alteration for cases with 3 probability ranks was developed. RESULTS: The accuracy and precision for selecting cancer-positive patches were 0.945 and 0.991, respectively. Predictive accuracy for the EGFR and KRAS groups in the validation data set was ~0.95, whereas that for the ALK and None groups was ~0.75 and ~ 0.80, respectively. Gene status was correctly predicted in the probability rank A cases. The model extracted characteristic conventional cytologic findings in images and a novel specific feature was discovered for the EGFR group. CONCLUSIONS: A gene alteration prediction model for lung cancers by machine learning based on cytologic images was successfully developed.

Combination of mean CT value and maximum CT value as a novel predictor of lepidic predominant lesions in small lung adenocarcinoma presenting as solid nodules.

Lung adenocarcinomas presenting as solid nodules are occasionally diagnosed as lepidic predominant lesions. The aim of this study was to clarify the histological structure and to identify factors predictive of lepidic predominant lesions. We retrospectively reviewed 38 patients that underwent lobectomy for small (≤ 2 cm) adenocarcinoma presenting as solid nodules. Resected tumor slides were reviewed and histological components were evaluated. Clinical and radiological data were analyzed to identify factors predictive of lepidic predominant lesions. Of 38 solid nodules, 9 (23.7%) nodules were lepidic predominant lesions. Five-year disease-free survival (DFS) rates were 100% for lepidic predominant lesions (n = 9) and 74.6% for non-lepidic predominant lesions (n = 29). Mean CT values (p = 0.039) and maximum CT values (p = 0.015) were significantly lower in lepidic predominant lesions compared with non-lepidic predominant lesions. For the prediction of lepidic predominant lesions, the sensitivity and specificity of mean CT value (cutoff, - 150 HU) were 77.8% and 82.8%, respectively, and those of maximum CT value (cutoff, 320 HU) were 77.8% and 72.4%, respectively. A combination of mean and maximum CT values (cutoffs of - 150 HU and 380 HU for mean CT value and maximum CT value, respectively) more accurately predicted lepidic predominant lesions, with a sensitivity and specificity of 77.8% and 86.2%, respectively. The prognosis of lepidic predominant lesions was excellent, even for solid nodules. The combined use of mean and maximum CT values was useful for predicting lepidic predominant lesions, and may help predict prognosis.