AI-guided histopathology predicts brain metastasis in lung cancer patients.

Brain metastases can occur in nearly half of patients with early and locally advanced (stage I-III) non-small cell lung cancer (NSCLC). There are no reliable histopathologic or molecular means to identify those who are likely to develop brain metastases. We sought to determine if deep learning (DL) could be applied to routine H&E-stained primary tumor tissue sections from stage I-III NSCLC patients to predict the development of brain metastasis.

Artificial Intelligence-Powered Assessment of Pathologic Response to Neoadjuvant Atezolizumab in Patients With NSCLC: Results From the LCMC3 Study.

Introduction: Pathologic response (PathR) by histopathologic assessment of resected specimens may be an early clinical end point associated with long-term outcomes with neoadjuvant therapy. Digital pathology may improve the efficiency and precision of PathR assessment. LCMC3 (NCT02927301) evaluated neoadjuvant atezolizumab in patients with resectable NSCLC and reported a 20% major PathR rate.

Development and validation of a decision tree for distinguishing pulmonary adenocarcinomas with mucinous features and metastatic colorectal adenocarcinoma.

Background: Diagnosis of mucinous carcinomas in the lung on transbronchial biopsy or fine-needle aspiration (FNA) samples can be difficult for the pathologist, because primary and metastatic tumors can have similar morphological, immunohistochemical, and molecular characteristics. Correct diagnosis is key to determine appropriate therapy and to distinguish primary from metastatic disease. This distinction often falls to the pathologist in patients with a history of mucinous adenocarcinoma of the colon.

Smoking exposure-induced bronchus-associated lymphoid tissue in donor lungs does not prevent tolerance induction after transplantation.

The presence of bronchus-associated lymphoid tissue (BALT) in donor lungs has been suggested to accelerate graft rejection after lung transplantation. Although chronic smoke exposure can induce BALT formation, the impact of donor cigarette use on alloimmune responses after lung transplantation is not well understood. Here, we show that smoking-induced BALT in mouse donor lungs contains Foxp3 T cells and undergoes dynamic restructuring after transplantation, including recruitment of recipient-derived leukocytes to areas of pre-existing lymphoid follicles and replacement of graft-resident donor cells.

Clinical and Histopathologic Characteristics of Recurrent Sarcoidosis in Posttransplant Lungs: 25 Years of Experience.

Lung transplantation is the definitive therapy for end-stage pulmonary sarcoidosis. While recurrent sarcoidosis in allografts has been described in several case reports, the incidence and clinicopathologic characteristics remain unclear. In this study, we characterize the clinical and histopathologic features of recurrent sarcoidosis diagnosed in posttransplant lung surveillance transbronchial biopsies (TBBx).

Ischemia reperfusion injury facilitates lung allograft acceptance through IL-33-mediated activation of donor-derived IL-5 producing group 2 innate lymphoid cells.

Pathways regulating lung alloimmune responses differ from most other solid organs and remain poorly explored. Based on our recent work identifying the unique role of eosinophils in downregulating lung alloimmunity, we sought to define pathways contributing to eosinophil migration and homeostasis. Using a murine lung transplant model, we have uncovered that immunosuppression increases eosinophil infiltration into the allograft in an IL-5-dependent manner.

Lymphatic drainage from bronchus-associated lymphoid tissue in tolerant lung allografts promotes peripheral tolerance.

Tertiary lymphoid organs are aggregates of immune and stromal cells including high endothelial venules and lymphatic vessels that resemble secondary lymphoid organs and can be induced at nonlymphoid sites during inflammation. The function of lymphatic vessels within tertiary lymphoid organs remains poorly understood. During lung transplant tolerance, Foxp3+ cells accumulate in tertiary lymphoid organs that are induced within the pulmonary grafts and are critical for the local downregulation of alloimmune responses.

Publisher Correction: SARS-CoV-2 infection of human ACE2-transgenic mice causes severe lung inflammation and impaired function.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

SARS-CoV-2 infection of human ACE2-transgenic mice causes severe lung inflammation and impaired function.

Although animal models have been evaluated for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, none have fully recapitulated the lung disease phenotypes seen in humans who have been hospitalized. Here, we evaluate transgenic mice expressing the human angiotensin I-converting enzyme 2 (ACE2) receptor driven by the cytokeratin-18 (K18) gene promoter (K18-hACE2) as a model of SARS-CoV-2 infection. Intranasal inoculation of SARS-CoV-2 in K18-hACE2 mice results in high levels of viral infection in lungs, with spread to other organs.

Bacterial products in donor airways prevent the induction of lung transplant tolerance.

Although postoperative bacterial infections can trigger rejection of pulmonary allografts, the impact of bacterial colonization of donor grafts on alloimmune responses to transplanted lungs remains unknown. Here, we tested the hypothesis that bacterial products present within donor grafts at the time of implantation promote lung allograft rejection. Administration of the toll-like receptor 2 (TLR2) agonist Pam Cys to Balb/c wild-type grafts triggered acute cellular rejection after transplantation into B6 wild-type recipients that received perioperative costimulatory blockade.

SARS-CoV-2 infection in the lungs of human ACE2 transgenic mice causes severe inflammation, immune cell infiltration, and compromised respiratory function.

Severe Acute Respiratory Syndrome Coronavirus -2 (SARS-CoV-2) emerged in late 2019 and has spread worldwide resulting in the Coronavirus Disease 2019 (COVID-19) pandemic. Although animal models have been evaluated for SARS-CoV-2 infection, none have recapitulated the severe lung disease phenotypes seen in hospitalized human cases. Here, we evaluate heterozygous transgenic mice expressing the human ACE2 receptor driven by the epithelial cell cytokeratin-18 gene promoter (K18-hACE2) as a model of SARS-CoV-2 infection.

IL-22 is required for the induction of bronchus-associated lymphoid tissue in tolerant lung allografts.

Long-term survival after lung transplantation remains profoundly limited by graft rejection. Recent work has shown that bronchus-associated lymphoid tissue (BALT), characterized by the development of peripheral nodal addressin (PNAd)-expressing high endothelial venules and enriched in B and Foxp3 T cells, is important for the maintenance of allograft tolerance. Mechanisms underlying BALT induction in tolerant pulmonary allografts, however, remain poorly understood.

Clinicopathologic characteristics of de novo nodular regenerative hyperplasia in pediatric liver transplant.

Liver NRH is seen in all patients age; however, more frequently in those over the age of 60 years and associated with multiple systemic diseases. In liver allograft recipients, the development of DnNRH has been linked with the use of azathioprine or vascular abnormalities. We present the clinicopathologic characteristics of 17 pediatric patients who underwent liver transplantation and subsequently developed DnNRH.

Bronchus-associated lymphoid tissue-resident Foxp3+ T lymphocytes prevent antibody-mediated lung rejection.

Antibody-mediated rejection (AMR) is a principal cause of acute and chronic failure of lung allografts. However, mechanisms mediating this oftentimes fatal complication are poorly understood. Here, we show that Foxp3+ T cells formed aggregates in rejection-free human lung grafts and accumulated within induced bronchus-associated lymphoid tissue (BALT) of tolerant mouse lungs.

Phase III Randomized, Placebo-Controlled, Double-Blind Trial of Celecoxib in Addition to Standard Chemotherapy for Advanced Non-Small-Cell Lung Cancer With Cyclooxygenase-2 Overexpression: CALGB 30801 (Alliance).

Purpose Tumor overexpression of cyclooxygenase-2 (COX-2) has been associated with worse outcome in non-small-cell lung cancer (NSCLC). In Cancer and Leukemia Group B (CALGB) 30203, we found that the selective COX-2 inhibitor celecoxib in addition to chemotherapy in advanced NSCLC improved progression-free and overall survival in patients with moderate to high COX-2 expression by immunohistochemistry (IHC). CALGB 30801 (Alliance) was designed to prospectively confirm that finding.

Pulmonary and pleural pathology: Contributions of Dr. Louis "Pepper" Dehner.

Dr. Louis Dehner is an internationally renowned surgical pathologist who has published multiple textbooks and has authored or co-authored nearly 400 original articles in the medical literature. While many think of him as a pediatric pathologist, he has contributed to the literature across virtually the entire breadth of surgical pathology, and the lung and pleura is no exception.

Significance of granulomatous inflammation in usual interstitial pneumonia.

Sarcoidosis is a systemic granulomatous disease of unclear etiology with characteristic pulmonary lesions. We describe 2 unique cases of sarcoidosis where after approximately 20 years of clinical quiescence, patients developed interstitial opacities on chest CT scan and an increase in shortness of breath. With lack of therapeutic response to a course of prednisone, both patients underwent a surgical lung biopsy that revealed a pattern consistent with Usual Interstitial Pneumonia (UIP) with honeycombing and fibroblastic foci.

Central memory CD8+ T lymphocytes mediate lung allograft acceptance.

Memory T lymphocytes are commonly viewed as a major barrier for long-term survival of organ allografts and are thought to accelerate rejection responses due to their rapid infiltration into allografts, low threshold for activation, and ability to produce inflammatory mediators. Because memory T cells are usually associated with rejection, preclinical protocols have been developed to target this population in transplant recipients. Here, using a murine model, we found that costimulatory blockade-mediated lung allograft acceptance depended on the rapid infiltration of the graft by central memory CD8+ T cells (CD44(hi)CD62L(hi)CCR7+).

Simultaneous necrotizing soft tissue infection and colonic necrosis caused by Clostridium septicum.

Background: Clostridial myonecrosis is an uncommon, highly lethal necrotizing soft tissue infection. The source may be occult at the time of clinical presentation. In cases caused by Clostridium septicum, there is an association with colorectal malignant disease, suggesting that underlying colonic pathology frequently is the source of the infection.

Emergency granulopoiesis promotes neutrophil-dendritic cell encounters that prevent mouse lung allograft acceptance.

The mechanisms by which innate immune signals regulate alloimmune responses remain poorly understood. In the present study, we show by intravital 2-photon microscopy direct interactions between graft-infiltrating neutrophils and donor CD11c(+) dendritic cells (DCs) within orthotopic lung allografts immediately after reperfusion. Neutrophils isolated from the airways of lung transplantation recipients stimulate donor DCs in a contact-dependent fashion to augment their production of IL-12 and expand alloantigen-specific IFN-γ(+) T cells.