STAT6 Variants Associate With Relapse of Eosinophilic Esophagitis in Patients Receiving Long-term Proton Pump Inhibitor Therapy.

BACKGROUND & AIMS: Based on histologic features, variants in STAT6 are associated with a poor initial response to proton pump inhibitor (PPI) therapy in pediatric patients with eosinophilic esophagitis (EoE). We investigated whether these genetic variants are associated with a poor long-term response in children with EoE who initially responded to PPI therapy. METHODS: We performed a prospective longitudinal cohort study of children ages 2 to 16 years who met the diagnostic criteria for EoE (≥15 eosinophils/high-power field [eos/hpf]), responded to 8 weeks of treatment with 2 mg/kg/d PPI (<15 eos/hpf), and whose dose then was reduced to 1 mg/kg/d PPI (maintenance therapy) for 1 year, at which point biopsy specimens were collected by endoscopy. Genomic DNA was isolated from formalin-fixed paraffin-embedded biopsy tissue and was genotyped for variants of STAT6. Remission of inflammation was assessed at eos/hpf thresholds of <15 and ≤5. RESULTS: Among 73 patients who received 1 mg/kg/d PPI maintenance therapy for 1 year, 13 patients (18%) had 6 to 14 eos/hpf, 36 patients (49%) had 5 or fewer eos/hpf, and 24 patients (33%) relapsed to EoE (≥15 eos/hpf). Carriage of any of 3 STAT6 variants in linkage disequilibrium (r2 ≥0.8; rs324011, rs167769, or rs12368672) was associated with a 2.3- to 2.8-fold increase in the odds of EoE relapse, and with a 2.8- to 4.1-fold increase in the odds of having 6 to 14 eos/hpf. For rs324011, the odds ratio [95% CI] for relapse was 2.77 [1.11, 6.92]; P = .029, and the odds ratio [95% CI] for having 6 to 14 eos/hpf was 3.06 [1.27, 7.36]; P = .012. CONCLUSIONS: Pediatric EoE patients who initially respond to PPI therapy and carry STAT6 variants rs324011, rs167769, or rs12368672 are at increased risk of relapse after 1 year of PPI maintenance therapy.

CYP2C19 and STAT6 Variants Influence the Outcome of Proton Pump Inhibitor Therapy in Pediatric Eosinophilic Esophagitis.

OBJECTIVE: Proton pump inhibitors (PPIs) are an effective treatment for eosinophilic esophagitis (EoE); however, only 30% to 60% of patients respond. Common genetic variants in CYP2C19 and STAT6 associate with PPI plasma concentration and magnitude of inflammatory response, respectively. Our objective was to determine if genetic variation in the genes for CYP2C19 and STAT6 influence differentiation between PPI responsive esophageal eosinophilia versus PPI nonresponsive EoE (PPI-REE, PPI-nonresponsive EoE). METHODS: Genomic DNA was isolated from 92 esophageal tissue biopsies collected from participants of a prospective clinical trial of high-dose PPI therapy for esophageal eosinophilia in children. RESULTS: Of the 92 patients examined, 57 (62%) were PPI-REE and 35 (38%) were PPI-nonresponsive EoE. Forty-six of the 92 patients were further characterized by pH probe monitoring; there was no association between reflux index and carriage of CYP2C1917 (P = 0.35). In children who received a PPI dose between ≥1.54 and ≤2.05 mg/kg/day, binary logistic regression modeling showed that carriage of CYP2C1917 associated with PPI-nonresponsive EoE (odds ratio (OR) [95% confidence interval (CI)] = 7.71 [1.21, 49.11], P = 0.031). Carriage of STAT6 allelic variant rs1059513 predicts PPI-REE (OR [95% CI] = 6.16 [1.44, 26.4], P = 0.028), whereas carriage of STAT6 rs324011 synergizes with CYP2C1917 to predict PPI-nonresponsive EoE (rs324011 OR [95% CI] = 5.56 [1.33, 20.72], P = 0.022; CYP2C1917 OR [95% CI] = 8.19[1.42, 50.57], P = 0.023). CONCLUSIONS: Common variants in CYP2C19 and STAT6 associate with a PPI-nonresponsive EoE outcome of PPI therapy for esophageal eosinophilia suggesting that response rates may be improved by adopting a genotype-guided approach to PPI dosing.

Serrated lesions and serrated polyposis syndrome.

The serrated pathway has been shown to be an alternative colorectal carcinogenetic route potentially accounting for up to one third of all CRCs. Serrated lesions, particularly SSPs, have been a focus of research during the past few years. They have well-established histological and molecular characteristics that account for their potential carcinogenetic risk through the accumulation BRAF, KRAS and methylator profile (CpG) mutations. Their endoscopic identification and resection represent a challenge because of their specific characteristics, and the need for an adequate specimen for histological diagnosis. Knowledge of these lesions is key, as is the adoption of established criteria for their endoscopic description and histological diagnosis. SPS is the maximum expression of involvement by serrated lesions, is associated with increased risk for CRC, and requires attentive endoscopic follow-up, as well as family screening. While the exact etiopathogenic mechanism remains unknown, current research will likely provide us with appropriate answers in the not too distant future.

Identification of fatty acid amide hydrolase as a metastasis suppressor in breast cancer.

Clinical management of breast cancer (BC) metastasis remains an unmet need as it accounts for 90% of BC-associated mortality. Although the luminal subtype, which represents >70% of BC cases, is generally associated with a favorable outcome, it is susceptible to metastatic relapse as late as 15 years after treatment discontinuation. Seeking therapeutic approaches as well as screening tools to properly identify those patients with a higher risk of recurrence is therefore essential. Here, we report that the lipid-degrading enzyme fatty acid amide hydrolase (FAAH) is a predictor of long-term survival in patients with luminal BC, and that it blocks tumor progression and lung metastasis in cell and mouse models of BC. Together, our findings highlight the potential of FAAH as a biomarker with prognostic value in luminal BC and as a therapeutic target in metastatic disease.

Histological inflammatory activity can predict endoscopic relapse in patients with ulcerative colitis who have achieved mucosal healing.

BACKGROUND AIMS: Current therapeutic goals in ulcerative colitis (UC) include clinical and endoscopic remission, named mucosal healing (MH). Despite MH, a proportion of patients suffer a clinical relapse, which has been related to histological inflammation. We aimed to identify which histopathological features or histopathological index cut-off was associated with endoscopic relapse (ER) in UC patients with MH. METHODS: Retrospective analysis of UC patients who underwent surveillance colonoscopy showing complete MH (endoscopic Mayo subscore=0) with random biopsies, and at least one more endoscopy along the follow-up. After a consensus meeting, expert pathologist performed histological assessment according to Simplified Geboes Score (SGS), Nancy Index (NI) and Robarts Histopathological Index (RHI). Other histopathological features were also evaluated. Patients were followed until ER or last endoscopy performed showing persistence of MH. RESULTS: A total of 95 patients (150 colonoscopies) were included. After mean follow-up of 31.2 months (SD 21.7), 33 patients (34.7%) suffered ER. Neutrophils in lamina propria (OR 2.6; P = 0.037), within the epithelium (OR 2.6; P = 0.03), SGS ≥3.1 (OR 2.6; P = 0.037), NI ≥2 (OR 2.6; P = 0.03) and RHI ≥5 (OR 2.6; P = 0.037) were associated with ER in univariate analysis. In multivariate analysis, eosinophils in the lamina propria (HR 2.5; P = 0.01) and clinical remission<12 months (HR 3.2; P = 0.002) were associated with ER. CONCLUSIONS: Histopathological findings in UC patients who have achieved endoscopic MH may predict ER. Standardized histopathology reports according to the presence of neutrophils, eosinophils or to defined cut-off of validated histopathologic indexes may represent a useful tool to predict ER and should be considered at therapeutic and surveillance decision process.

Distribution of eosinophils in the gastrointestinal tract of children with no organic disease.

BACKGROUND: This study aimed to assess the eosinophil (eos) density of the mucosa of the gastrointestinal (GI) tract in children undergoing endoscopic procedures following an extensive workup, without diagnosis of an organic disease. METHODS: Biopsies from GI endoscopies performed at 3 major children's hospitals (Athens, Madrid and Rome), between January 2012 and June 2018, were evaluated by a single pathologist in each center. Peak eos counts were expressed /high power field and /mm2. Other histological abnormalities were also reported. RESULTS: A total of 111 children (median age 11 years; 48 boys) underwent upper endoscopy (333 biopsies), while 44 (median age 12; 25 boys) underwent ileocolonoscopy (262 biopsies). The median (interquartile range) eos/mm2 were as follows: esophagus 0 (0-0); stomach 0 (0-3); duodenum 22 (13-29); ileum 29 (19-46); cecum 39 (25-71); ascending colon 24 (20-41); transverse colon 27 (21-57); descending colon 21 (13-27); sigmoid colon 22 (13-30); and rectum 10 (6-22). Geographical variations in GI tissue eos counts were found amongst the participating centers, but the causative factors need further evaluation. Functional GI disorders according to the Rome IV criteria were diagnosed in 73 children (37 boys, median age 13 years). No differences were found between children with or without functional GI disorder diagnosis, with regard to eos density in the GI tract. CONCLUSION: The reported peak counts of GI tissue eos in children with no organic diseases provide normative values that may be useful in the evaluation of children with GI symptoms suggestive of eosinophilic GI disorders.

Bone Marrow-derived Mesenchymal Stem Cells and Chronic Allograft Disease in a Bronchiolitis Obliterans Animal Model.

INTRODUCTION: Bronchiolitis obliterans (BO) is the most common expression of chronic allograft dysfunction in lung transplantation. Moreover, BO represents the major cause of death in the long-term after this procedure. On the other hand, mesenchymal stem cells have been tested in animal models of BO aiming to interfere in its development. The aim of this experimental study is to explore the role of bone-marrow derived stem cells (BMSCs) as a preventive intervention of BO occurrence. MATERIALS AND METHODS: This an experimental randomized study. A bronchiolitis obliterans animal model in rats was reproduced: heterotopical tracheal transplant model in lung parenchyma. Five of these animals were used as control group. After setting up the model, individuals were divided in 3 groups of treatment (n=15), in which BMSCs were administered in 3 different time points after the tracheal transplant (tracheal transplantation and BMSCs administration occurred the same day, group G0; after 7 days, group G7; after 14 days, group G14. In addition, within each group, BMSCs were administered through 3 different routes: endotracheally, endovascular and topically in the lung parenchyma). Animals were sacrificed at 21 days. Histology, fluorescence in situ hybridization and immunohistochemistry techniques were performed for identifying stem cells. RESULTS: Compared to control group, animals receiving BMSCs showed large neovessels in a loose fibrous matrix. Group G7 showed less fibrosis (p<0.033) and edema (p<0.028). Moreover, G7 animals receiving stem cells endotracheally showed no fibrosis (p<0.008). Alveolar-like patches of tissue were observed among all groups (53.4%, 46.7% and 40% in G0, G7 and G14 respectively), consisting of cells expressing both stem and alveolar cells biomarkers. CONCLUSION: BMSCs modify the course of bronchiolitis obliterans and differentiate into alveolar cells. Endotracheal administration of BMSCs 7 days after the heterotopical tracheal transplant might be considered an effective way to prevent BO in this animal model.

Primary pulmonary lymphoma: diagnosis and follow-up of 6 cases and review of an uncommon entity.

AIMS AND BACKGROUND: Primary pulmonary lymphoma is an uncommon disease with a poorly defined management. We reviewed and followed the cases of primary pulmonary lymphoma in our institution to gather an estimation of this entity in our population. DESIGN AND METHODS: We reviewed the records of all patients with biopsy-proven lymphoma of the lung. The main diagnostic criterion for primary pulmonary lymphoma was the absence of extrapulmonary involvement. RESULTS: We identified 6 cases of primary pulmonary lymphoma among 33 patients with biopsy-proven lymphoma of the lung evaluated in our center in a 12-year period. A radiological abnormality in an asymptomatic patient was the most common clinical presentation. Four cases were low-grade and two cases high-grade non-Hodgkin PPL. Histopathologic analyses of lung specimens obtained by transbronchial biopsy were sufficient for a diagnosis in 5 of the 6 cases and avoided invasive surgical maneuvers. Most patients followed an indolent course, but with a tendency to relapse. CONCLUSIONS: Although clinical management of this entity is undefined, we feel bronchoscopic study, which is less aggressive than surgery, may be an adequate procedure for a diagnosis. Mono-chemotherapy using alkylating agents and careful clinical observation may be the best therapeutic approach for these patients, since most of them have favorable outcomes, whatever the treatment modalities.

Sentinel lymph node biopsy in breast cancer: the role of micrometastasis.

Intraoperative sentinel lymph node biopsy is widely used in patients with early-stage breast cancer for staging the axilla. The conventional analysis of the SLN has classically been performed by frozen section or touch imprint with a rapid H&E (hematoxylin and eosin) staining. Because of the risk of false-negative results, it has been replaced by the one-step acid amplification (OSNA) assay, a molecular diagnostic assay for the detection of cytokeratin 19 mRNA expression. Due to the controversial for the use of OSNA to evaluate the SLN because of its cost-effective and the lack of consensus to perform or avoid a lymphadenectomy when there is micrometastasis, we analyze 410 patients subjected to SLN biopsy in Hospital Puerta de Hierro, Madrid (Spain). Of the total of nodes, 223 (54.4 %) were processed throughout frozen-section examination and imprint cytology and 187 (45.6 %) throughout OSNA. The specificity of the frozen-section histological examination was of 100 %, with a sensitivity of 83.33 % (95 % CI 73.07-93.60). Of the 40 patients with definitive micrometastasis in the SLN, axillary dissection was performed in 90 % of the patients, with subsequent positive affectation in four of them (11.11 %). Based on our result and taking into account that 10 % of the lymphadenectomy performed after micrometastasis are positive, we do not believe that lymphadenectomy should be avoided after N(mi+) is detected in a SLN.

Dedifferentiated liposarcoma of the pyriform sinus: report of a case and review of the literature.

Laryngeal and hypopharyngeal liposarcomas are extraordinarily infrequent tumors. To the best of our knowledge there are fewer than 40 well-documented cases reported to date. Almost all of them are well-differentiated liposarcomas, with only 2 laryngeal-hypopharyngeal dedifferentiated liposarcomas. Dedifferentiated liposarcoma is defined as a well-differentiated liposarcoma with areas of high-grade spindle cell nonlipogenic sarcoma. The well-differentiated areas may be of a lipoma-like, sclerosing, or mixed type, and the dedifferentiated areas most frequently are of malignant fibrous hystiocytoma-like type. Despite its commonly pleomorphic histology, dedifferentiated liposarcoma does not behave as aggressively as most pleomorphic sarcomas of adulthood; however, it has the capacity to metastasize, in contrast to its well-differentiated counterpart. We present a case of dedifferentiated liposarcoma arising in the pyriform sinus, an event only twice reported previously in the literature.

Heterotopic tracheal transplantation animal model of bronchiolitis obliterans: a reproducible model.

BACKGROUND: Chronic rejection or bronchiolitis obliterans (BO) is the main cause of morbidity and mortality 1 year after lung transplantation. The objective of this study was to develop a reproducible animal model that mimics the typical histological findings in human BO after lung transplantation. MATERIAL AND METHODS: We used 2 rat strains - Lewis (L) and Wistar (W) - and transplanted a segment of donor trachea into each recipient. The animals were divided into 2 groups: 1) donor and recipient of the same strain (W-W), and 2) donor and recipient of different strains (L-W). From each group, we created 4 subgroups examined at different time-points after transplantation (7, 14, 21, and 28 days). Variables were: degree of narrowing of the tracheal lumen, histological findings classified into 1 of 5 patterns, location of the ink (green or black), and presence of foreign body granuloma. RESULTS: In the W-W group, we observed a gradual onset of fibrosis, notable at 21 and 28 days post-implant. In the L-W group, obliteration of the tracheal lumen was observed in all animals, with acute inflammation by day 7, and fibrosis from then on, loose fibrosis by day 14, and frank fibrosis on days 21 and 28. Green ink was observed in vascular structures, located in granulation tissue in the early phases of the BO-type lesion, then the staining becoming less clear as the histological features developed towards frank fibrosis. This trend was seen in both groups. CONCLUSIONS: The obliteration and fibrosis are more extensive if the donor and recipient are from different strains (L-W). Histological findings in the L-W group corresponded to progressive fibrosis until day 21.

Ossifying adult xanthogranuloma.

Although a xanthogranuloma is a relatively common benign cutaneous condition and ossification has been observed within many cutaneous lesions, the association between ossification and xanthogranuloma has not, to our knowledge, been reported previously. We believe we describe for the first time the case of a xanthogranuloma with marked osseous metaplasia on the trunk of a 41-year-old woman. Microscopically, the lesion showed typical features of a xanthogranuloma, with the exceptional feature of exuberant bone formation. The presence of bone within this lesion is likely secondary to a metaplastic process.

Aggressive angiomyxoma: an ultrastructural study of four cases.

The histogenesis of the aggressive angiomyxoma of the vulvo-vaginal region was studied. Four cases of aggressive angiomyxoma were examined by using light microscopy, electron microscopy, and immunohistochemistry. Myofibroblastic from smooth muscle cell differentiation was distinguished by paying close attention to the structures of the neoplastic cell membrane. Aggressive angiomyxomas exhibit subtle features of smooth muscle differentiation, suggesting that the neoplastic cells differentiate from a multipotent perivascular cell.