Sepsis-trained macrophages promote antitumoral tissue-resident T cells.

Sepsis induces immune alterations, which last for months after the resolution of illness. The effect of this immunological reprogramming on the risk of developing cancer is unclear. Here we use a national claims database to show that sepsis survivors had a lower cumulative incidence of cancers than matched nonsevere infection survivors. We identify a chemokine network released from sepsis-trained resident macrophages that triggers tissue residency of T cells via CCR2 and CXCR6 stimulations as the immune mechanism responsible for this decreased risk of de novo tumor development after sepsis cure. While nonseptic inflammation does not provoke this network, laminarin injection could therapeutically reproduce the protective sepsis effect. This chemokine network and CXCR6 tissue-resident T cell accumulation were detected in humans with sepsis and were associated with prolonged survival in humans with cancer. These findings identify a therapeutically relevant antitumor consequence of sepsis-induced trained immunity.

Iron and Vitamin B12 Deficiency in Patients with Autoimmune Gastritis and Helicobacter pylori Gastritis: Results from a Prospective Multicenter Study.

INTRODUCTION: Iron and vitamin B12 deficiencies are common in patients with atrophic gastritis, but there are limited data on the prevalence of these deficiencies in different types of atrophic gastritis. METHODS: This multicenter, prospective study assessed micronutrient concentrations in histologically confirmed autoimmune gastritis (AIG, n = 45), Helicobacter pylori-related non-autoimmune gastritis (NAIG, n = 109), and control patients (n = 201). A multivariate analysis was performed to determine factors influencing those deficiencies. RESULTS: The median vitamin B12 concentration was significantly lower in AIG (367.5 pg/mL, Q1, Q3: 235.5, 524.5) than in NAIG (445.0 pg/mL, Q1, Q3: 355.0, 565.0, p = 0.001) and control patients (391.0 pg/mL, Q1, Q3: 323.5, 488.7, p = 0.001). Vitamin B12 deficiency was found in 13.3%, 1.5%, and 2.8% of AIG, NAIG, and control patients, respectively. Similarly, the median ferritin concentration was significantly lower in AIG (39.5 ng/mL, Q1, Q3: 15.4, 98.3 ng/mL) than in NAIG (80.5 ng/mL, Q1, Q3: 43.6, 133.9, p = 0.04) and control patients (66.5 ng/mL, Q1, Q3: 33.4, 119.8, p = 0.007). Iron deficiency and iron deficiency adjusted to CRP were present in 28.9% and 33.3% of AIG, 12.8% and 16.5% of NAIG, and 12.9% and 18.4% of controls, respectively. Multivariate analysis demonstrated that AIG patients had a higher risk of developing vitamin B12 deficiency (OR: 11.52 [2.85-57.64, p = 0.001]) and iron deficiency (OR: 2.92 [1.32-6.30, p = 0.007]) compared to control patients. Factors like age, sex, and H. pylori status did not affect the occurrence of vitamin B12 or iron deficiency. CONCLUSION: Iron and vitamin B12 deficiencies are more commonly observed in patients with AIG than in those with NAIG or control patients. Therefore, it is essential to screen for both iron and vitamin B12 deficiencies in AIG patients and include the treatment of micronutrient deficiencies in the management of atrophic gastritis patients.

Deep Learning for Detecting BRCA Mutations in High-Grade Ovarian Cancer Based on an Innovative Tumor Segmentation Method From Whole Slide Images.

BRCA1 and BRCA2 genes play a crucial role in repairing DNA double-strand breaks through homologous recombination. Their mutations represent a significant proportion of homologous recombination deficiency and are a reliable effective predictor of sensitivity of high-grade ovarian cancer (HGOC) to poly(ADP-ribose) polymerase inhibitors. However, their testing by next-generation sequencing is costly and time-consuming and can be affected by various preanalytical factors. In this study, we present a deep learning classifier for BRCA mutational status prediction from hematoxylin-eosin-safran-stained whole slide images (WSI) of HGOC. We constituted the OvarIA cohort composed of 867 patients with HGOC with known BRCA somatic mutational status from 2 different pathology departments. We first developed a tumor segmentation model according to dynamic sampling and then trained a visual representation encoder with momentum contrastive learning on the predicted tumor tiles. We finally trained a BRCA classifier on more than a million tumor tiles in multiple instance learning with an attention-based mechanism. The tumor segmentation model trained on 8 WSI obtained a dice score of 0.915 and an intersection-over-union score of 0.847 on a test set of 50 WSI, while the BRCA classifier achieved the state-of-the-art area under the receiver operating characteristic curve of 0.739 in 5-fold cross-validation and 0.681 on the testing set. An additional multiscale approach indicates that the relevant information for predicting BRCA mutations is located more in the tumor context than in the cell morphology. Our results suggest that BRCA somatic mutations have a discernible phenotypic effect that could be detected by deep learning and could be used as a prescreening tool in the future.

Atrophic Gastritis and Autoimmunity: Results from a Prospective, Multicenter Study.

Despite a global decrease, gastric cancer (GC) incidence appears to be increasing recently in young, particularly female, patients. The causal mechanism for this "new" type of GC is unknown, but a role for autoimmunity is suggested. A cascade of gastric precancerous lesions, beginning with chronic atrophic gastritis (CAG), precedes GC. To test the possible existence of autoimmunity in patients with CAG, we aimed to analyze the prevalence of several autoantibodies in patients with CAG as compared to control patients. Sera of 355 patients included in our previous prospective, multicenter study were tested for 19 autoantibodies (anti-nuclear antibodies, ANA, anti-parietal cell antibody, APCA, anti-intrinsic factor antibody, AIFA, and 16 myositis-associated antibodies). The results were compared between CAG patients (n = 154), including autoimmune gastritis patients (AIG, n = 45), non-autoimmune gastritis patients (NAIG, n = 109), and control patients (n = 201). ANA positivity was significantly higher in AIG than in NAIG or control patients (46.7%, 29%, and 27%, respectively, p = 0.04). Female gender was positively associated with ANA positivity (OR 0.51 (0.31-0.81), p = 0.005), while age and H. pylori infection status were not. Myositis-associated antibodies were found in 8.9% of AIG, 5.5% of NAIG, and 4.4% of control patients, without significant differences among the groups (p = 0.8). Higher APCA and AIFA positivity was confirmed in AIG, and was not associated with H. pylori infection, age, or gender in the multivariate analysis. ANA antibodies are significantly more prevalent in AIG than in control patients, but the clinical significance of this finding remains to be established. H. pylori infection does not affect autoantibody seropositivity (ANA, APCA, AIFA). The positivity of myositis-associated antibodies is not increased in patients with CAG as compared to control patients. Overall, our results do not support an overrepresentation of common autoantibodies in patients with CAG.

Serum pepsinogens can help to discriminate between H. pylori-induced and auto-immune atrophic gastritis: Results from a prospective multicenter study.

BACKGROUND: Serum pepsinogen (PG) testing is recommended by the European guidelines for diagnosis of chronic atrophic gastritis (CAG). However, wide variations in diagnostic performances are observed, due to the differences in the extent of gastric atrophy, and possibly in its origin (Helicobacter pylori-, autoimmune (AIG)). AIM: To analyze the diagnostic performances of PGs testing according to these different parameters, using enzyme-linked-immunosorbent serologic assay (ELISA) and chemiluminescent immunoassay (CLEIA). METHODS: Serum samples from patients having undergone gastroscopy with biopsies in five French centers were collected prospectively. Sensitivity (Se), specificity (Sp), and Area Under Curve were analyzed according to the extent and origin of CAG. RESULTS: Overall, 344 patients (156 males [45%]; mean age 58.8 [±14.2] years) were included, among whom 44 had AIG. Diagnostic performances of PG I for the detection of corpus CAG were excellent, with Se and Sp of 92.7% and 99.1% for ELISA and 90.5% and 98.2% for CLEIA, respectively. For AIG, corresponding values were 97.7% and 97.4% for ELISA, and 95.6% and 97.1% for CLEIA. In multivariate analysis, PG levels were associated with the auto-immune origin (p<0.001) but not with the extent of the atrophic gastritis. CONCLUSIONS: Pepsinogens are highly efficient for the diagnosis of corpus-limited CAG and allow to discriminate AIG from H. pylori-induced gastritis.

Serum Pepsinogens Combined with New Biomarkers Testing Using Chemiluminescent Enzyme Immunoassay for Non-Invasive Diagnosis of Atrophic Gastritis: A Prospective, Multicenter Study.

BACKGROUND: Analysis of serum biomarkers for the assessment of atrophic gastritis (AG), a gastric precancerous lesion, is of growing interest for identification of patients at increased risk of gastric cancer. The aim was to analyze the diagnostic performance of serum pepsinogen testing using another method, chemiluminescent enzyme immunoassay (CLEIA), as well as of other new potential biomarkers. MATERIAL AND METHODS: The sera of patients considered at increased risk of gastric cancer and undergoing upper endoscopy collected in our previous prospective, multicenter study were tested for pepsinogen I (PGI) and II (PGII), interleukin-6 (IL-6), human epididymal protein 4 (HE-4), adiponectin, ferritin and Krebs von den Lungen (KL-6) using the CLEIA. The diagnostic performance for the detection of AG was calculated by taking histology as the reference. RESULTS: In total, 356 patients (162 men (46%); mean age 58.6 (±14.2) years), including 152 with AG, were included. For the detection of moderate to severe corpus AG, sensitivity and specificity of the pepsinogen I/II ratio were of 75.0% (95%CI 57.8-87.9) and 92.6% (88.2-95.8), respectively. For the detection of moderate to severe antrum AG, sensitivity of IL-6 was of 72.2% (95%CI 46.5-90.3). Combination of pepsinogen I/II ratio or HE-4 showed a sensitivity of 85.2% (95%CI 72.9-93.4) for the detection of moderate to severe AG at any location. CONCLUSION: This study shows that PG testing by CLEIA represents an accurate assay for the detection of corpus AG. Additionally, IL-6 and HE-4 may be of interest for the detection of antrum AG. MINI-ABSTRACT: Pepsinogens testing by chemiluminescent enzyme immunoassay is accurate for the detection of corpus atrophic gastritis. IL-6 and HE-4 maybe of interest for the detection of antrum atrophic gastritis.

Mapping of colorectal carcinoma diseases with activation of Wnt/beta-catenin signalling pathway using hierarchical clustering approach.

AIMS: To map the colorectal carcinoma (CRC) diseases with significant Wnt signalling pathway activation for delineating their clinicopathological and molecular profiles. METHODS: Mapping is based on hierarchical clustering analyses of a series of 283 CRCs. Data tabulated were histopathological patterns, immunophenotypic differentiation, RAS, RAF, CTNNB1 mutations and microsatellite instability status, tumour-infiltrating lymphocytes (TILs) and genetic setting. Beta-catenin expression in more than 10% of cell nuclei in the centre of tumour serves as a surrogate marker of significant activation of Wnt signalling pathway. RESULTS: Nuclei beta-catenin expression was present in 95% of CRCs; 56% of them met the criteria of high level of nuclei beta-catenin expression (≥10%). Proportion of beta-catenin positive nuclei was significantly higher in younger patients, rectal and left-sided colonic carcinomas. CRCs with high level of nuclei beta-catenin expression were regrouped into three clusters: (1) microsatellite stability (MSS) CRCs with no constitutive MAPK pathway activation including 90% of low-grade adenocarcinoma, NOS, with intestinal differentiation without TILs; (2) RAS-mutated MSS CRCs including low-grade adenocarcinoma, NOS, with intestinal differentiation and mucinous adenocarcinoma without TILs; (3) MSI-H CRCs including both BRAF-mutated CRCs evolving from serrated pathway and CTNNB1-mutated CRCs associated with Lynch syndrome. CONCLUSIONS: MSS low-grade adenocarcinoma, NOS, with intestinal differentiation without TILs ('crypt-like adenocarcinoma') might be the morphological pending of canonical molecular subtype of CRC defined as displayed molecular epithelial differentiation and upregulation of WNT in consensus molecular classification of CRC.

High-Density of FcγRIIIA+ (CD16+) Tumor-Associated Neutrophils in Metastases Improves the Therapeutic Response of Cetuximab in Metastatic Colorectal Cancer Patients, Independently of the HLA-E/CD94-NKG2A Axis.

Antibody-dependent cellular cytotoxicity (ADCC) in the anti-tumor effect of cetuximab in metastatic colorectal cancer (mCRC) is only based on the impact of FcγRIIIA (CD16) polymorphisms as predictive of therapeutic response. However, nature, density and therapeutic impact of FcγRIIIA+ (CD16) effector cells in tumor remain poorly documented. Moreover, the inhibition of cetuximab-mediated ADCC induced by NK cells by the engagement of the new inhibitory CD94-NKG2A immune checkpoint has only been demonstrated in vitro. This multicentric study aimed to determine, on paired primary and metastatic tissue samples from a cohort of mCRC patients treated with cetuximab: 1) the nature and density of FcγRIIIA+ (CD16) immune cells, 2) the expression profile of HLA-E/ß2m by tumor cells as well as the density of CD94+ immune cells and 3) their impact on both objective response to cetuximab and survival. We demonstrated that FcγRIIIA+ (CD16) intraepithelial immune cells mainly correspond to tumor-associated neutrophils (TAN), and their high density in metastases was significantly associated with a better response to cetuximab, independently of the expression of the CD94/NKG2A inhibitory immune checkpoint. However, HLA-E/ß2m, preferentially overexpressed in metastases compared with primary tumors and associated with CD94+ tumor infiltrating lymphocytes (TILs), was associated with a poor overall survival. Altogether, these results strongly support the use of bispecific antibodies directed against both EGFR and FcγRIIIA (CD16) in mCRC patients, to boost cetuximab-mediated ADCC in RAS wild-type mCRC patients. The preferential overexpression of HLA-E/ß2m in metastases, associated with CD94+ TILs and responsible for a poor prognosis, provides convincing arguments to inhibit this new immune checkpoint with monalizumab, a humanized anti-NKG2A antibody, in combination with anti- FcγRIIIA/EGFR bispecific antibodies as a promising therapeutic perspective in RAS wild-type mCRC patients.

Systematic upper endoscopy concomitant with colonoscopy performed within the colorectal cancer screening program: Impact on the patients' management.

BACKGROUND AND AIMS: The French colorectal cancer screening program is based on a fecal immunochemical test, followed by colonoscopy in case of positivity. The benefit of adding a concomitant upper endoscopy to detect upper digestive lesions (precancerous or others) is still debated. Our aim was to evaluate the frequency of upper digestive lesions detected by upper endoscopy performed concomitantly with colonoscopy following a positive fecal immunochemical test, and their impact on the patients' management (i.e., surveillance, medical treatment, endoscopic or surgical procedure). METHODS: Data of all the patients who consulted for a positive test between May 2016 and May 2019 in our center, and for whom concomitant upper endoscopy and colonoscopy were performed, were analyzed retrospectively. Patients with significant history of upper gastrointestinal diseases or with current gastrointestinal symptoms were excluded. RESULTS: One hundred patients were included [median age (min-max): 62 (50-75), men 64%]. Macroscopic and/or microscopic upper digestive lesions were found in 58 of them (58%): Helicobacter pylori infection in 17 patients, gastric precancerous lesions in 9 patients (chronic atrophic gastritis with intestinal metaplasia, n=8, low grade dysplasia, n=1), Barrett's esophagus requiring surveillance in 4 patients, and 1 duodenal adenoma with low-grade dysplasia. In 44 patients (44%), the upper endoscopy findings had an impact on patients' management, with no significant difference between the groups with positive (CRC or advanced adenoma)- or negative (any other lesions or normal) colonoscopy. CONCLUSION: A systematic upper endoscopy combined with colonoscopy for positive fecal immunochemical test could represent an efficient strategy for upper digestive lesions screening in France. Further studies are necessary to confirm these results and to evaluate cost-effectiveness of this approach.

Full-field optical coherence tomography: novel imaging technique for extemporaneous high-resolution analysis of mucosal architecture in human gut biopsies.

Full-field optical coherence tomography (FFOCT) is an imaging technique of biological tissue based on tissue light reflectance analysis. We evaluated the feasibility of imaging fresh digestive mucosal biopsies after a quick mounting procedure (5 min) using two distinct modalities of FFOCT. In static FFOCT mode, we gained high-resolution images of general gut tissue-specific architecture, such as oesophageal papillae, gastric pits, duodenal villi and colonic crypts. In dynamic FFOCT mode, we imaged individual epithelial cells of the mucosal lining with a cellular or subcellular resolution and identified cellular components of the lamina propria. FFOCT represents a promising dye-free imaging tool for on-site analysis of gut tissue remodelling.

Analysis of enteric nervous system and intestinal epithelial barrier to predict complications in Hirschsprung's disease.

In Hirschsprung's disease (HSCR), postoperative course remains unpredictable. Our aim was to define predictive factors of the main postoperative complications: obstructive symptoms (OS) and Hirschsprung-associated enterocolitis (HAEC). In this prospective multicentre cohort study, samples of resected bowel were collected at time of surgery in 18 neonates with short-segment HSCR in tertiary care hospitals. OS and HAEC were noted during postoperative follow-up. We assessed the enteric nervous system and the intestinal epithelial barrier (IEB) in ganglionic segments by combining immunohistochemical, proteomic and transcriptomic approaches, with functional ex vivo analysis of motility and para/transcellular permeability. Ten HSCR patients presented postoperative complications (median follow-up 23.5 months): 6 OS, 4 HAEC (2 with OS), 2 diarrhoea (without OS/HAEC). Immunohistochemical analysis showed a significant 41% and 60% decrease in median number of nNOS-IR myenteric neurons per ganglion in HSCR with OS as compared to HSCR with HAEC/diarrhoea (without OS) and HSCR without complications (p = 0.0095; p = 0.002, respectively). Paracellular and transcellular permeability was significantly increased in HSCR with HAEC as compared to HSCR with OS/diarrhoea without HAEC (p = 0.016; p = 0.009) and HSCR without complications (p = 0.029; p = 0.017). This pilot study supports the hypothesis that modulating neuronal phenotype and enhancing IEB permeability may treat or prevent postoperative complications in HSCR.

Evaluation of a Phone Call Reminder Strategy in the Surveillance of Patients with Gastric Precancerous Lesions Lost to Follow-Up.

BACKGROUND: Surveillance of gastric precancerous lesions (GPL) may reduce gastric cancer (GC)-related mortality, but some patients with GPL are lost to follow-up. OBJECTIVE: The aim of this study was to evaluate the feasibility and efficacy of a "phone-call" strategy in surveillance of the lost to follow-up patients. PATIENTS AND METHODS: Among all the patients diagnosed with GPL (atrophic gastritis, intestinal metaplasia, low-grade dysplasia) between 2000 and 2015, we identified those who should undergo surveillance endoscopy according to the current guidelines. They were contacted by telephone and invited to undergo endoscopy with gastric biopsies for histological analysis. RESULTS: Among 535 patients with GPL, 134 were contacted. Sixty-two (46%) could not be joined, 36 did not have endoscopy for other reasons, and finally, 36 patients (22 males, median age 65 years) were included. After the median time interval of 57 months between 2 endoscopies, 18 patients showed stability, 11 regression, and 7 progression of GPL, including 1 patient who developed GC. CONCLUSION: Despite several telephone calls, only one-third of the contacted patients could be brought to surveillance endoscopy. Most of the patients showed stability of GPL, but 1 progressed to GC and could be successfully treated.

Selective SIRPα blockade reverses tumor T cell exclusion and overcomes cancer immunotherapy resistance.

T cell exclusion causes resistance to cancer immunotherapies via immune checkpoint blockade (ICB). Myeloid cells contribute to resistance by expressing signal regulatory protein-α (SIRPα), an inhibitory membrane receptor that interacts with ubiquitous receptor CD47 to control macrophage phagocytosis in the tumor microenvironment. Although CD47/SIRPα-targeting drugs have been assessed in preclinical models, the therapeutic benefit of selectively blocking SIRPα, and not SIRPγ/CD47, in humans remains unknown. We report a potent synergy between selective SIRPα blockade and ICB in increasing memory T cell responses and reverting exclusion in syngeneic and orthotopic tumor models. Selective SIRPα blockade stimulated tumor nest T cell recruitment by restoring murine and human macrophage chemokine secretion and increased anti-tumor T cell responses by promoting tumor-antigen crosspresentation by dendritic cells. However, nonselective SIRPα/SIRPγ blockade targeting CD47 impaired human T cell activation, proliferation, and endothelial transmigration. Selective SIRPα inhibition opens an attractive avenue to overcoming ICB resistance in patients with elevated myeloid cell infiltration in solid tumors.

Integrative molecular profiling of autoreactive CD4 T cells in autoimmune hepatitis.

BACKGROUND & AIMS: In most autoimmune disorders, crosstalk of B cells and CD4 T cells results in the accumulation of autoantibodies. In autoimmune hepatitis (AIH), the presence of anti-soluble liver antigen (SLA) autoantibodies is associated with reduced overall survival, but the associated autoreactive CD4 T cells have not yet been characterised. Herein, we isolated and deeply characterised SLA-specific CD4 T cells in patients with AIH. METHODS: We used brief ex vivo restimulation with overlapping SLA peptides to isolate and phenotype circulating SLA-specific CD4 T cells, and integrative single-cell RNA-seq (scRNA-seq) to characterise their transcriptome and T-cell receptor (TCR) repertoire. Autoreactive TCRs were cloned and used to identify dominant SLA-derived epitopes. SLA-specific CD4 T cells were tracked in peripheral blood through TCR sequencing to identify their phenotypic niche. We further characterised disease-associated peripheral blood T cells by high-content flow cytometry in 42 patients with AIH and 17 controls with non-alcoholic steatohepatitis. RESULTS: Autoreactive SLA-specific CD4 T cells were only detected in patients with anti-SLA autoantibodies and had a memory PD-1+CXCR5-CCR6-CD27+ phenotype. ScRNA-seq revealed their pro-inflammatory/B-helper profile. SLA81-100 and SLA177-204 contain dominant T-cell epitopes. Autoreactive TCR clonotypes were predominantly found in the memory PD-1+CXCR5-CD4 T cells, which were significantly increased in the blood of patients with AIH and supported B-cell differentiation through IL-21. Finally, we identified specific T-cell phenotypes linked to disease activity and IgG level during AIH. CONCLUSIONS: We provide a deep characterisation of rare circulating autoreactive CD4 T cells and identify their peripheral reservoir in AIH. We also propose a specific phenotype of autoreactive T cells related to AIH disease activity, which will be essential to track, delineate, and potentially target these pathogenic cells. LAY SUMMARY: One principal characteristic of autoimmune hepatitis (AIH), like for many other autoimmune diseases, is the accumulation of autoantibodies produced by B lymphocytes following their interaction with autoreactive CD4 T lymphocytes. In this study, we identified and characterised with high resolution these CD4 T cells. This will be essential to track, delineate, and potentially target them during AIH.

A panel of stomach-specific biomarkers (GastroPanel®) for the diagnosis of atrophic gastritis: A prospective, multicenter study in a low gastric cancer incidence area.

BACKGROUND: Analysis of serum biomarkers for the assessment of atrophic gastritis (AG), considered as gastric precancerous lesion, is of growing interest and recommended by current guidelines. Our aim was to evaluate the diagnostic performance of a panel of biomarkers (GastroPanel®) for the detection of AG in France, a country of a low gastric cancer (GC) incidence. MATERIAL AND METHODS: In this prospective, multicenter, cross-sectional study, consecutive patients considered at increased risk of GC and undergoing upper endoscopy with gastric biopsies were included. Blood samples were collected for the analysis of GastroPanel® (association of Pepsinogens I and II, Gastrin-17, and Helicobacter pylori serology) using ELISA. The results of GastroPanel® were compared to the results of histology considered as the reference. RESULTS: Between 2016 and 2019, 344 patients (148 cases with AG, 196 controls without AG) were included. Sensitivity, specificity, positive, and negative predictive values for the detection of AG by GastroPanel® were of 39.9% (95% CI 31.9; 48.2), 93.4% (95% CI 88.9; 96.4), 81.9 (95% CI 71.1; 90.0), and 67.3 (95% CI 61.4; 72.8), respectively. The sensitivity was significantly higher for the detection of severe AG [60.8% (95% CI 46.1; 74.6) P = .015] and corpus AG [61.0% (95% CI 49.2; 72.0), P = .004]. Diagnostic performances of GastroPanel® tended to be better than those of Pepsinogen I alone, but the difference did not reach statistical significance (P = .068). CONCLUSION: Serum pepsinogen and GastroPanel® tests show promising results for the detection of AG, especially of corpus AG and severe AG, in patients at high risk of GC in France.

Long-Term Follow-up of Gastric Precancerous Lesions in a Low GC Incidence Area.

INTRODUCTION: Data on the evolution of gastric precancerous lesions (GPL), especially in countries of a Low gastric cancer incidence area are limited. Our objective was to study a long-term evolution of GPL in France. METHODS: All the patients diagnosed with GPL (atrophic gastritis, intestinal metaplasia [IM], and dysplasia) between 2000 and 2015 and fulfilling criteria for evolution assessment (at least 2 endoscopies, minimal follow-up of 6 months, and at least 2 biopsies obtained from the antrum and corpus) were included. Clinical and endoscopic data were analyzed, and histological samples were reviewed by an expert pathologist with evaluation of the Operative Link on Gastric Intestinal Metaplasia Assessment stage and type of IM. RESULTS: From the 507 patients with GPL, 79 fulfilled the strict criteria. During a mean follow-up of 66 months, during which the patients had a mean number of 4 endoscopies (min-max: 2-21) with 9 biopsies/endoscopy, a stability was observed in 70% of patients. Progression occurred in 14% of patients, within a mean delay of 62.1 months (min-max: 17-99). Progression of the lesions was significantly higher in patients with incomplete type of IM (relative risk of progression for incomplete IM: 11.5; 95% confidence interval 2.5-53.1). Regression of IM occurred in 16% of the patients, after a mean delay of 90 months. DISCUSSION: This study shows that the patients with antrum-limited IM, especially of incomplete type, are at the highest risk of developing gastric cancer. In most patients, however, the lesions remain stable, which highlights the need for additional markers to better target the patients at risk of progression.

The inhibitory receptor CD94/NKG2A on CD8+ tumor-infiltrating lymphocytes in colorectal cancer: a promising new druggable immune checkpoint in the context of HLAE/ß2m overexpression.

We previously demonstrated that HLA-E/ß2m overexpression by tumor cells in colorectal cancers is associated with an unfavorable prognosis. However, the expression of its specific receptor CD94/NKG2 by intraepithelial tumor-infiltrating lymphocytes, their exact phenotype and function, as well as the relation with the molecular status of colorectal cancer and prognosis remain unknown. Based on a retrospective cohort of 234 colorectal cancer patients, we assessed the expression of HLA-E, ß2m, CD94, CD8, and NKp46 by immunohistochemistry on tissue microarray. The expression profile of HLA-E/ß2m on tumor cells and the density of tumor-infiltrating lymphocytes were correlated to the clinicopathological and molecular features (Microsatellite status, BRAF and RAS mutations). Then, from the primary tumors of 27 prospective colorectal cancers, we characterized by multiparameter flow cytometry the nature (T and/or NK cells) and the co-expression of the inhibitory NKG2A or activating NKG2C chain of ex vivo isolated CD94+ tumor-infiltrating lymphocytes. Their biological function was determined using an in vitro redirected cytolytic activity assay. Our results showed that HLA-E/ß2m was preferentially overexpressed in microsatellite instable tumors compared with microsatellite stable ones (45% vs. 19%, respectively, p = 0.0001), irrespective of the RAS or BRAF mutational status. However, HLA-E/ß2m+ colorectal cancers were significantly enriched in CD94+ intraepithelial tumor-infiltrating lymphocytes in microsatellite instable as well as in microsatellite stable tumors. Those CD94+ tumor-infiltrating lymphocytes mostly corresponded to CD8+ αß T cells, and  to a lesser extent to NK cells, and mainly co-expressed a functional inhibitory NKG2A chain. Finally, a high number of CD94+ intraepithelial tumor-infiltrating lymphocytes in close contact with tumor cells was independently associated with a worse overall survival. In conclusion, these findings strongly suggest that HLA-E/ß2m-CD94/NKG2A represents a new druggable inhibitory immune checkpoint, preferentially expressed in microsatellite instable tumors, but also in a subgroup of microsatellite stable tumors, leading to a new opportunity in colorectal cancer immunotherapies.