[Renal synovialosarcoma: What about pyelic cytology to make a diagnosis?] / Synovialosarcome primitif du rein : si tout était déjà dans les urines pyéliques ?

Synovialosarcoma is a malignant mesenchymal tumor of young adults that occurs in the deep soft tissues, particularly around large joints. When it occurs in more unusual sites, it could present a significant diagnostic challenge. In this case, a 19-year-old girl was treated for a pyloric mass. A pyelic urine cytology performed simultaneously with a pyloric biopsy proved to be a significant element of orientation and perfectly concordant with the histopathological aspect of the pyelic mass after nephrectomy. We report here the first case of renal synovialosarcoma documented in pyelic urine.

[Fibro-osseous pseudotumor of the digits: One of USP6-related fibroblastic/myofibroblastic tumors]. / La pseudotumeur fibro-osseuse des doigts : une tumeur fibroblastique/myofibroblastique liée à USP6.

Fibro-osseous pseudotumor of the digits is a benign tumour closely related to myositis ossificans. It is a rare lesion seldom reported in the literature. We report the case of a 33-year-old woman with lancinating pain in the first phalanx of the second finger of the right hand, associated with inflammation. The histopathological examination of the surgical excision biopsy of the lesion revealed a spindle-shaped proliferation within a sclerosing, hyaline, and osteoid stroma. In our observation, immunohistochemistry and molecular biology are the main elements that helped to establish the diagnosis and eliminate the various differential diagnoses, despite a non-specific histopathological aspect.

Amelioration of experimental autoimmune encephalomyelitis by in vivo reprogramming of macrophages using pro-resolving factors.

BACKGROUND: Reinstating inflammation resolution represents an innovative concept to regain inflammation control in diseases marked by chronic inflammation. While most therapeutics target inflammatory molecules and inflammatory effector cells and mediators, targeting macrophages to initiate inflammation resolution to control neuroinflammation has not yet been attempted. Resolution-phase macrophages are critical in the resolution process to regain tissue homeostasis, and are programmed through the presence and elimination of apoptotic leukocytes. Hence, inducing resolution-phase macrophages might represent an innovative therapeutic approach to control and terminate dysregulated neuroinflammation. METHODS: Here, we investigated if the factors released by in vitro induced resolution-phase macrophages (their secretome) are able to therapeutically reprogram macrophages to control neuroinflammation in the model of experimental autoimmune encephalomyelitis (EAE). RESULTS: We found that injection of the pro-resolutive secretome reduced demyelination and decreased inflammatory cell infiltration in the CNS, notably through the in vivo reprogramming of macrophages at the epigenetic level. Adoptive transfer experiments with in vivo or in vitro reprogrammed macrophages using such pro-resolutive secretome confirmed the stability and transferability of this acquired therapeutic activity. CONCLUSIONS: Overall, our data confirm the therapeutic activity of a pro-resolution secretome in the treatment of ongoing CNS inflammation, via the epigenetic reprogramming of macrophages and open with that a new therapeutic avenue for diseases marked by neuroinflammation.

Evaluation of immune infiltrate according to the HER2 status in colorectal cancer.

BACKGROUND AND AIMS: In colorectal cancer (CRC), HER2 targeting is a promising treatment and immune infiltrate is an important area of research and strategy. Data regarding HER2 status and immune infiltrate are lacking. The aim of this study was to compare the immune infiltrate between HER2 amplified and non-amplified categories in proficient MisMatchRepair (pMMR)/microsatellite stable (MSS) CRC. METHODS: HER2 immunohistochemistry (IHC) and fluorescence in situ hybridization were performed in a retrospective series of 654 CRC. Lymphocyte infiltrate was analysed by anti-CD3, CD8 and CD4 IHC and evaluated digitally using QuPath software. RESULTS: Among the 654 CRC, we first observed a decreased CD3+ and CD8+ infiltrate between HER2 amplified (all IHC 3+ except one 2+) and non-amplified HER2 2+ IHC CRC (p = 0.059 and 0.072 respectively). A supplementary analysis of 258 pMMR/MSS CRC from the previous cohort, displaying all the IHC scores (0, 1+, 2+, 3+), showed a lower CD3+ infiltrate between HER2 amplified versus HER2 0 (p = 0.002), 1+ (p = 0.088) and non-amplified 2+ (p = 0.081) IHC cases. CONCLUSIONS: Our original findings suggest that in pMMR/MSS CRC, the immune infiltrate is reduced in HER2 amplified versus other HER2 categories. These data might be useful for future strategies combining anti-HER2 treatments and immune checkpoint inhibitors and need to be confirmed in larger CRC cohorts.

Should the artery be trimmed before anastomosis in every finger replantation/revascularization case? Prospective, single-center, multidisciplinary study over 46 months.

INTRODUCTION: Despite optimal arterial anastomosis, some finger replantations fail. Our objective was to evaluate how the mechanism of injury (MOI) affects the artery's microscopic appearance and the success of anastomosis. We hypothesized that the MOI influences arterial histology and microsurgical success. METHODS: This single-center prospective study enrolled patients who had an acute traumatic arterial injury of the hand and/or wrist. The proximal and distal ends of the artery were trimmed before anastomosis in every case. The arterial margins were analyzed in anatomical pathology. Clinical follow-up along with an ultrasound arterial patency check was carried out at 1 month postoperative. RESULTS: Between 2018 and 2022, 104 patients were enrolled with a follow-up of 12 months. Macroscopically, 42% of the arterial margins were dilapidated. Histological analysis found damage in 74% of surgical specimens: blast (100%)>laceration by mechanical or power tool (92%; 82%)>amputation by mechanical or power tool (80%; 67%)>laceration by glass (50%)>crush injury (33%). The arterial margins were more likely to be normal based on the histological analysis when the MOI was laceration by glass (p<.05; OR=3.72) and the patient was 65 years or older (p<.01). Risk factors for anastomosis failure were an amputation by power tool (p<.01, OR 8.19) and shorter length of arterial resection (p<.02). The clinical failure rate was 7.8% and the patency failure rate was 10.4%. DISCUSSION: Histological arterial lesions correlate with the MOI. Trimming >2mm from the proximal and distal arterial ends is recommended for all MOI before arterial end-to-end anastomosis. For blast injuries or amputation, we recommend trimming>4mm and using a vein bypass graft. This study's findings could lead to a change in surgical practices. LEVEL OF EVIDENCE: II; well-conducted non-randomized comparative study; recommendation grade B: scientific presumption.

[Dasatinib-induced follicular lymphoid hyperplasia, an entity to know]. / Hyperplasie lymphoïde folliculaire induite par la prise de dasatinib, une entité à connaître.

Follicular lymphoid hyperplasia induced by dasatinib is an entity recently described. It is sometimes difficult to rule out the diagnostic of small B-cell lymphoma. Usually, the node is swollen, with follicular architecture conserved, composed by germinal centers with variable size and shape, with a hight number of mitoses and tingible bodies macrophages inside. Follicular lymphoid hyperplasia is isolated or associated with multiple reactive patterns. The immunohistochemical profil of germinal centers is CD20+, CD10+, BCL6+, BCL2-. Swollen node disappears in a short time after dasatinib discontinuation. Clinicians and pathologists need to be aware of this entity, so as not to avoid mistakenly suspect lymphoma when lymphadenopathy occurs in a patient with chronic myeloid leukemia treated with dasatinib.

Molecular diagnosis of alveolar echinococcosis in patients based on frozen and formalin-fixed paraffin-embedded tissue samples.

Confirmed diagnosis of alveolar echinococcosis (AE) is based on pathological criteria and molecular evidence. This parasite-borne disease, caused by the cestode Echinococcus multilocularis, sparingly involves humans as a dead-end host. In humans, the parasite mainly colonizes the liver but can colonize any organ and cause atypical forms, often difficult to characterize clinically. Moreover, molecular methods may be suitable to make the diagnosis of AE in cases of atypical forms, extra-hepatic localizations, or immunosuppressed patients. The aim of this study was to determine the most relevant published PCR techniques, for diagnosis of AE in patients and adopt the best strategy for molecular diagnosis depending on the nature of the tested sample. In this study, we evaluated nine end-point PCR assays and one real-time PCR assay (qPCR), targeting mitochondrial genes, using a total of 89 frozen or formalin-fixed paraffin-embedded (FFPE) samples from either 48 AE or 9 cystic echinococcosis patients. Targeted fragment-genes ranged from 84 to 529 bp. Six PCR assays were able to amplify the DNA of 100% of the frozen AE-samples and for one PCR, 69.8% of the FFPE AE-samples. The 16S rrnL PCR (84 bp) was positive in PCR for 77% of the AE samples and in qPCR for 86.5%. The sensitivity of the PCR assays was higher for fresh samples and FFPE samples stored for less than 5 years. The qPCR assay further increased sensitivity for the tested samples, confirming the need for the development of an Echinococcus spp. qPCR to improve the molecular diagnosis of echinococcoses.

TITLE: Diagnostic moléculaire de l'échinococcose alvéolaire chez les patients à partir d'échantillons de tissus congelés et fixés au formol et inclus en paraffine. ABSTRACT: La confirmation diagnostique de l'échinococcose alvéolaire (EA) est basée sur des critères anatomo-pathologiques et moléculaires. Cette maladie d'origine parasitaire, causée par le cestode Echinococcus multilocularis, implique sporadiquement l'homme, impasse parasitaire. Chez l'homme, le parasite colonise principalement le foie mais peut coloniser tout organe et causer des formes atypiques, souvent difficiles à caractériser cliniquement. En outre, les méthodes moléculaires permettent de réaliser le diagnostic de l'EA dans les formes atypiques, les localisations extra-hépatiques ou chez les patients immunodéprimés. Le but de cette étude était de déterminer les techniques PCR publiées les plus pertinentes, pour le diagnostic de l'EA chez les patients et adopter la meilleure stratégie par diagnostic moléculaire en fonction de la nature de l'échantillon testé. Dans cette étude nous avons évalué neuf PCR en point-final et une PCR-temps-réel (qPCR), ciblant des gènes mitochondriaux, utilisant 89 échantillons congelés ou fixés en paraffine (FFPE) de patients EA (n = 48) ou présentant une échinococcose kystique (n = 9). Les fragments de gènes ciblés allaient de 84 à 529 pb. Six tests PCR ont permis d'amplifier l'ADN de 100 % des échantillons EA congelés, et pour une PCR, 69,8 % des échantillons EA-FFPE. La PCR 16S rrnL (84 pb) était positive en PCR pour 77 % des échantillons EA et en qPCR pour 86,5 %. La sensibilité des tests PCR était plus importante pour les échantillons congelés et les FFPE stockés moins de 5 ans. Le test qPCR a permis d'augmenter la sensibilité pour les échantillons testés, confirmant le besoin de développement d'une qPCR Echinococcus spp. pour améliorer le diagnostic moléculaire des échinococcoses.

High-density lipoprotein infusion protects from acute graft-versus-host disease in experimental allogeneic hematopoietic cell transplantation.

Acute graft-versus-host disease (aGVHD) is a major limitation of the therapeutic potential of allogeneic hematopoietic cell transplantation. Lipopolysaccharides (LPS) derived from intestinal gram-negative bacteria are well-known aGVHD triggers and amplifiers. Here, we explored the LPS metabolism in aGVHD mouse models using an innovative quantification method. We demonstrated that systemic LPS accumulation after transplantation was due, at least partly, to a defect in its clearance through lipoprotein-mediated transport to the liver (i.e., the so-called reverse LPS transport). After transplantation, reduced circulating HDL concentration impaired LPS neutralization and elimination through biliary flux. Accordingly, HDL-deficient (Apoa1tm1Unc ) recipient mice developed exacerbated aGVHD. Repeated administration of HDL isolated from human plasma significantly decreased the mortality and the severity of aGVHD. While the potential role of HDL in scavenging circulating LPS was examined in this study, it appears that HDL plays a more direct immunomodulatory role by limiting or controlling aGVHD. Notably, HDL infusion mitigated liver aGVHD by diminishing immune infiltration (e.g., interferon-γ-secreting CD8+ T cells and non-resident macrophages), systemic and local inflammation (notably cholangitis). Hence, our results revealed the interest of HDL-based therapies in the prevention of aGVHD.

[The first data challenge of the french society of pathology: An international competition in 2020, a research tool in A.I. for the future?] / Le premier data challenge organisé par la Société Française de Pathologie : une compétition internationale en 2020, un outil de recherche en intelligence artificielle pour l'avenir ?

The french society of pathology (SFP) organized in 2020 its first data challenge with the help of Health Data Hub (HDH). The organisation of this event first consisted in recruiting almost 5000 slides of uterus cervical biopsies obtained in 20 pathology centers. After having made sure that patients did not refuse to include their slides in the project, the slides were anonymised, digitized and annotated by expert pathologists, and were finally uploaded on a data challenge platform for competitors all around the world. Competitors teams had to develop algorithms that could distinguish among four diagnostic classes in epithelial lesions of uterine cervix. Among many submissions by competitors, the best algorithms obtained an overall score close to 95%. The best 3 teams shared 25k€ prizes during a special session organised during the national congress of the SFP. The final part of the competition lasted only 6 weeks and the goal of SFP and HDH is now to allow for the collection to be published in open access. This final step will allow data scientists and pathologists to further develop artificial intelligence algorithms in this medical area.

Can AI predict epithelial lesion categories via automated analysis of cervical biopsies: The TissueNet challenge?

The French Society of Pathology (SFP) organized its first data challenge in 2020 with the help of the Health Data Hub (HDH). The organization of this event first consisted of recruiting nearly 5000 cervical biopsy slides obtained from 20 pathology centers. After ensuring that patients did not refuse to include their slides in the project, the slides were anonymized, digitized, and annotated by expert pathologists, and finally uploaded to a data challenge platform for competitors from around the world. Competing teams had to develop algorithms that could distinguish 4 diagnostic classes in cervical epithelial lesions. Among the many submissions from competitors, the best algorithms achieved an overall score close to 95%. The final part of the competition lasted only 6 weeks, and the goal of SFP and HDH is now to allow for the collection to be published in open access for the scientific community. In this report, we have performed a "post-competition analysis" of the results. We first described the algorithmic pipelines of 3 top competitors. We then analyzed several difficult cases that even the top competitors could not predict correctly. A medical committee of several expert pathologists looked for possible explanations for these erroneous results by reviewing the images, and we present their findings here targeted for a large audience of pathologists and data scientists in the field of digital pathology.

HPV16 Load Is a Potential Biomarker to Predict Risk of High-Grade Cervical Lesions in High-Risk HPV-Infected Women: A Large Longitudinal French Hospital-Based Cohort Study.

High-risk HPV (hrHPV) testing has been implemented as a primary screening tool for cervical cancer in numerous countries. However, there is still a need for relevant triage strategies to manage hrHPV positive women to avoid excessive referral to colposcopy. The objective of this study was to assess, in women infected by hrHPV and presenting no or mild cytological abnormalities, HPV16 and HPV18 viral loads to predict the development of cervical high-grade lesion. Among 2102 women positive for hrHPV, 885 had no lesion or mild cytological abnormalities at baseline and had at least one follow-up (FU) visit. HPV16 and HPV18 prevalence was 25.9% and 8.4%, respectively. Of those women, 15% developed a high-grade lesion during the FU. An HPV16 viral load cut-off set at 3.2 log10GE/103 cells permitted to identify a subgroup of women at high risk of developing high-grade cervical lesion (HR = 2.67; 95% CI 1.80-3.97; p ≤ 0.0001). No specific HPV18 viral load threshold could have been defined in regard to the present study. In multivariate analysis, HPV16 load (absence/log10GE/103 cells < 3.2 vs. ≥3.2), RLU/PC 239 (1-100 pg/mL vs. >100 pg/mL) and cytology (normal vs abnormal) were independently associated with a significant increased risk of high-grade lesion development and were used to construct the prognostic score. In conclusion, HPV16 load is a relevant biomarker to identify women at high risk for developing cervical precancerous lesions.

Adverse outcome in follicular lymphoma is associated with MYC rearrangements but not MYC extra copies.

Follicular lymphomas (FLs) with MYC rearrangements (MYC-R) and extra copies of MYC (MYC-EC) are rare and the prognosis impact is uncertain. We conducted a retrospective study including 321 FL patients, among whom 259 (81%) had no 8q24 alterations and 62 (19%) were assigned to 8qAlt. Forty-five cases were classified as MYC-EC and six as MYC-R. MYC-R patients were significantly older (P = 0·008), had higher follicular lymphoma international prognostic index (FLIPI) stage (P = 0·05) and ß2-microglobulin (ß2m; P = 0·05). Among patients treated with immuno-chemotherapy, four presented a MYC-R and 25 a MYC-EC. Univariate analysis showed the absence of significant difference between MYC-EC and normal MYC (MYC-NL) regarding progression-free survival (PFS; HR1·3; 95% CI [0·4-1·6]) and specific overall survival (SOS; HR 1·6; 95% CI [0·4-5·7]). Those results were compared to data from the PRIMA trial. This confirmed that MYC-EC had no impact on PFS (P = 0·86) or SOS (P = 0·9). Conversely, MYC-R was associated with a trend to inferior outcome regarding PFS (HR : 6·1; 95% CI [2·2-17·1]; P = 0·00026), lymphoma-related death (SOS; HR 13·6; 95% CI [2·9-65]; P = 0·00014) and risk of transformation (transformation-free survival (TFS); HR 82·7; 95% CI [14·8-463·4]; P < 0·0001). In conclusion, MYC-EC has no prognostic impact in FL but MYC-R FL tended to be associated with an increased risk of transformation and poorer outcome.

Combined grade and nuclear grade are prognosis predictors of epithelioid malignant peritoneal mesothelioma: a multi-institutional retrospective study.

Epithelioid mesothelioma is the most prevalent subtype of diffuse malignant peritoneal mesothelioma. A recently described nuclear-grading system predicted survival in patients with epithelioid malignant pleural mesothelioma. The present study was undertaken to validate this grading system in epithelioid malignant peritoneal mesothelioma (EMPM) and to compare to combined grade, including nuclear atypia, mitotic count, and tumor necrosis. Cases of EMPM, from 1995 to 2018, were analyzed from 7 French institutions from RENAPE network. Solid growth, tumor necrosis, nuclear atypia, and mitotic count were evaluated by at least 3 pathologists from the RENAPATH group. The predictions in terms of OS and PFS of nuclear grade and combined grade were analyzed. Nuclear grade was computed combining nuclear atypia score and mitotic count into a grade of I-III. Another system combining nuclear atypia score, mitotic score, and tumor necrosis was evaluated and defined as a combined grade I-III. A total of 138 cases were identified. The median follow-up was 38.9 months (range: 1.1-196.6). Nuclear and combined grades III were independently associated with a shorter OS (p < 0.05), and a shorter PFS (p < 0.05). Patients with combined grade I tumors had the best overall and progression-free survivals, in comparison to nuclear grade I. In this large multicentric study, combined grade and nuclear grade were the best independent predictors of OS and PFS in EMPM. These systems should be easily described by pathologists involved into the management of malignant peritoneal mesothelioma, because of their potential therapeutic implications.

Thoracic NUT carcinoma: Common pathological features despite diversity of clinical presentations.

NUT carcinoma (NC), formerly known as NUT midline carcinoma, is a rare and very aggressive cancer. It is genetically defined by the presence of acquired chromosomal rearrangement of the NUTM1 (NUclear protein in Testis Midline carcinoma family member 1) gene at chromosome 15q14 with a member of the bromodomain-containing protein (BRD) family gene, usually BRD4. Although primarily reported in the head and neck, and mediastinum locations of younger individuals, it is now established that NC arises in multiple sites in patients of all ages, with no gender predilection. NC is very likely to be underdiagnosed because of a lack of awareness of both clinicians and pathologists on the one hand, and of a nonspecific histological presentation on the other hand. As it is indistinguishable from other poorly differentiated carcinomas, pathologists should consider NC as a differential diagnosis of any poorly differentiated tumour. Diagnosis is now easily made by immunohistochemistry, using a highly sensitive and specific NUT monoclonal antibody. Despite chemo- or chemo-radiotherapy, the prognosis of this tumour remains very poor. We report here a series of 3 cases of NC with different clinical and pathological presentations in order to draw attention on some common morphological features that can help clinicians and pathologists to think about this rare entity.

[Primary liposarcomas of the digestive tract: Diversity of clinicopathological presentations and diagnostic challenges]. / Liposarcomes primitifs du tube digestif : diversité des présentations clinicopathologiques et challenges diagnostiques.

Sarcomas are rare tumours that represent less than 1% of all malignant tumours in adults. Liposarcomas are among the most common malignant mesenchymal tumours. They are preferentially located in the limbs and the retroperitoneum. Liposarcomas primarily arising in the digestive tract are exceptional with a few cases reported in the literature. Their clinical presentation is variable and the symptoms are not specific. Anatomopathological examination remains the gold standard for the diagnosis and the classification of these tumours, which are divided into 5 histological types according to the 5th edition of the WHO classification of soft tissue tumours. We report two observations of unusual digestive liposarcomas, located in the oesophagus and the colon, emphasizing the variability of the diagnostic challenges, depending on the clinical presentation, the histological type and the analysed material.

Peritoneal or mesenteric tumours revealing histiocytosis.

OBJECTIVE: Peritoneal or mesenteric tumours may correspond to several tumour types or tumour-like conditions, some of them being represented by histiocytosis. This rare condition often poses diagnostic difficulties that can lead to important time delay in targeted therapies. Our aim was to describe main features of histiocytoses with mesenteric localisation that can improve the diagnostic process. DESIGN: We performed a retrospective study on 22 patients, whose peritoneal/mesenteric biopsies were infiltrated by histiocytes. RESULTS: Abdominal pain was the revealing symptom in 10 cases, and 19 patients underwent surgical biopsies. The diagnosis of histiocytosis was proposed by initial pathologists in 41% of patients. The other initial diagnoses were inflammation (n=7), sclerosing mesenteritis (n=4) and liposarcoma (n=1). The CD163/CD68+CD1a- histiocytes infiltrated subserosa and/or deeper adipose tissues in 16 and 14 cases, respectively. A BRAFV600E mutation was detected within the biopsies in 11 cases, and two others were MAP2K1 mutated. The final diagnosis was histiocytosis in 18 patients, 15 of whom had Erdheim-Chester disease. The median diagnostic delay of histiocytosis was 9 months. Patients treated with BRAF or MEK inhibitors showed a partial response or a stable disease. One patient died soon after surgery, and five died by the progression of the disease. CONCLUSION: Diagnosis of masses arising in the mesentery should be carefully explored as one of the possibilities in histiocytosis. This diagnosis is frequently missed on mesenteric biopsies. Molecular biology for detecting the mutations in BRAF or in genes of the MAP kinase pathway is a critical diagnostic tool.

Tertiary lymphoid structures in epithelioid malignant peritoneal mesothelioma are associated with neoadjuvant chemotherapy, but not with prognosis.

Epithelioid mesothelioma is the most prevalent subtype of diffuse malignant peritoneal mesothelioma. The relationship between a strong adaptive immune response and a better prognosis in malignant solid tumors is widely known. Due to the low incidence of epithelioid malignant peritoneal mesothelioma (EMPM), very little is known about their immune micro-environment. We encountered several cases of tertiary lymphoid structures in EMPM in a previous study and aimed to investigate in the same series the prevalence, clinicopathological features, and the prognostic impact associated with tertiary lymphoid structures in EMPM (TLS-EMPM). Cases of EMPM, from 1995 to 2018, were retrieved from 7 French institutions from the RENAPE Network. The predictions in terms of overall survival (OS) and progression-free survival (PFS) of TLS-EMPM were analyzed. We report 52 cases of TLS-EMPM among a series of 138 cases of EMPM. TLS-EMPM was significantly associated with neoadjuvant chemotherapy, and was not a prognostic indicator for OS (p = 0.652) and PFS (p = 0.804) in our series. TLS is a component of the host immune response to EMPM significantly associated with neoadjuvant chemotherapy, but was not a predictor of prognosis for overall and progression-free survivals in this series. These findings provide another possible etiology for tertiary lymphoid structures.

Pro-Resolving Factors Released by Macrophages After Efferocytosis Promote Mucosal Wound Healing in Inflammatory Bowel Disease.

Nonresolving inflammation is a critical driver of several chronic inflammatory diseases, including inflammatory bowel diseases (IBD). This unresolved inflammation may result from the persistence of an initiating stimulus or from the alteration of the resolution phase of inflammation. Elimination of apoptotic cells by macrophages (a process called efferocytosis) is a critical step in the resolution phase of inflammation. Efferocytosis participates in macrophage reprogramming and favors the release of numerous pro-resolving factors. These pro-resolving factors exert therapeutic effects in experimental autoimmune arthritis. Here, we propose to evaluate the efficacy of pro-resolving factors produced by macrophages after efferocytosis, a secretome called SuperMApo, in two IBD models, namely dextran sodium sulfate (DSS)-induced and T cell transfer-induced colitis. Reintroducing these pro-resolving factors was sufficient to decrease clinical, endoscopic and histological colitis scores in ongoing naive T cell-transfer-induced colitis and in DSS-induced colitis. Mouse primary fibroblasts isolated from the colon demonstrated enhanced healing properties in the presence of SuperMApo, as attested by their increased migratory, proliferative and contractive properties. This was confirmed by the use of human fibroblasts isolated from patients with IBD. Exposure of an intestinal epithelial cell (IEC) line to these pro-resolving factors increased their proliferative properties and IEC acquired the capacity to capture apoptotic cells. The improvement of wound healing properties induced by SuperMApo was confirmed in vivo in a biopsy forceps-wound colonic mucosa model. Further in vivo analysis in naive T cell transfer-induced colitis model demonstrated an improvement of intestinal barrier permeability after administration of SuperMApo, an intestinal cell proliferation and an increase of α-SMA expression by fibroblasts, as well as a reduction of the transcript coding for fibronectin (Fn1). Finally, we identified TGF-ß, IGF-I and VEGF among SuperMApo as necessary to favor mucosal healing and confirmed their role both in vitro (using neutralizing antibodies) and in vivo by depleting these factors from efferocytic macrophage secretome using antibody-coated microbeads. These growth factors only explained some of the beneficial effects induced by factors released by efferocytic macrophages. Overall, the administration of pro-resolving factors released by efferocytic macrophages limits intestinal inflammation and enhance tissue repair, which represents an innovative treatment of IBD.