Neurotropism of SARS-CoV-2: A Pathological Examination of Neurosurgical Specimens

BACKGROUND AND OBJECTIVES

Neurological manifestations may occur in more than 80% of patients hospitalized with COVID-19 infection, including severe disruptions of the central nervous system (CNS), such as strokes, encephalitis, or seizures. Although the primary pathophysiological mechanism for the effects of COVID-19 in CNS remains unknown, evidence exists for both direct injury from neuroinvasion and indirect effects from disruptions in systemic inflammatory and coagulation pathways. In this study, we analyzed CNS tissue from living patients to better understand these processes.

METHODS

With institutional review board approval and patient consent, samples that would be otherwise discarded from patients with active or recent (within 6 days of surgery) COVID-19 infection undergoing neurosurgical intervention were collected and tested for the presence of SARS-CoV-2 using immunohistochemistry, in situ hybridization, electron microscopy, and reverse transcription polymerase chain reaction.

RESULTS

Five patients with perioperative mild-to-moderate COVID-19 infection met inclusion criteria (2 male, 3 female; mean age 38.8 ± 13.5 years). Neurosurgical diagnoses included a glioblastoma, a ruptured arteriovenous malformation, a ruptured posterior inferior cerebellar artery aneurysm, a middle cerebral artery occlusion, and a hemorrhagic pontine cavernous malformation. Samples analyzed included the frontal lobe cortex, olfactory nerve, arteriovenous malformation/temporal lobe parenchyma, middle cerebral artery, cerebellum, and cavernous malformation/brainstem parenchyma. Testing for the presence of SARS-CoV-2 was negative in all samples.

CONCLUSION

The CNS is likely not a significant viral reservoir during mild-to-moderate COVID-19 infection, although direct neuroinvasion is not definitively excluded. Additional testing to help elucidate the relative contributions of direct and indirect pathways for CNS injury from COVID is warranted.

Single-Cell Characterization of Pulmonary Nodules Implicates Suppression of Immunosurveillance across Early Stages of Lung Adenocarcinoma

A greater understanding of molecular, cellular, and immunological changes during the early stages of lung adenocarcinoma development could improve diagnostic and therapeutic approaches in patients with pulmonary nodules at risk for lung cancer. To elucidate the immunopathogenesis of early lung tumorigenesis, we evaluated surgically resected pulmonary nodules representing the spectrum of early lung adenocarcinoma as well as associated normal lung tissues using single-cell RNA sequencing and validated the results by flow cytometry and multiplex immunofluorescence (MIF). Single-cell transcriptomics revealed a significant decrease in gene expression associated with cytolytic activities of tumor-infiltrating natural killer and natural killer T cells. This was accompanied by a reduction in effector T cells and an increase of CD4+ regulatory T cells (Treg) in subsolid nodules. An independent set of resected pulmonary nodules consisting of both adenocarcinomas and associated premalignant lesions corroborated the early increment of Tregs in premalignant lesions compared with the associated normal lung tissues by MIF. Gene expression analysis indicated that cancer-associated alveolar type 2 cells and fibroblasts may contribute to the deregulation of the extracellular matrix, potentially affecting immune infiltration in subsolid nodules through ligand-receptor interactions. These findings suggest that there is a suppression of immune surveillance across the spectrum of early-stage lung adenocarcinoma.

SIGNIFICANCE

Analysis of a spectrum of subsolid pulmonary nodules by single-cell RNA sequencing provides insights into the immune regulation and cell-cell interactions in the tumor microenvironment during early lung tumor development.

Neutrophilic inflammation promotes SARS-CoV-2 infectivity and augments the inflammatory responses in airway epithelial cells

In response to viral infection, neutrophils release inflammatory mediators as part of the innate immune response, contributing to pathogen clearance through virus internalization and killing. Pre-existing co- morbidities correlating to incidence of severe COVID-19 are associated with chronic airway neutrophilia. Furthermore, examination of COVID-19 explanted lung tissue revealed a series of epithelial pathologies associated with the infiltration and activation of neutrophils, indicating neutrophil activity in response to SARS- CoV-2 infection. To determine the impact of neutrophil-epithelial interactions on the infectivity and inflammatory responses to SARS-CoV-2 infection, we developed a co-culture model of airway neutrophilia. SARS-CoV-2 infection of the airway epithelium alone does not result in a notable pro-inflammatory response from the epithelium. The addition of neutrophils induces the release of proinflammatory cytokines and stimulates a significantly augmented pro-inflammatory response subsequent SARS-CoV-2 infection. The resulting inflammatory response is polarized with differential release from the apical and basolateral side of the epithelium. Additionally, the integrity of the epithelial barrier is impaired with notable epithelial damage and infection of basal stem cells. This study reveals a key role for neutrophil-epithelial interactions in determining inflammation and infectivity in response to SARS-CoV-2 infection.

Predictors of survival in portopulmonary hypertension: a 20-year experience

BACKGROUND AND OBJECTIVES

Portopulmonary hypertension (PoPH) is a rare complication of portal hypertension associated with poor survival. Scarce data is available on predictors of survival in PoPH with conflicting results. We sought to characterize the outcomes and variables associated with survival in a large cohort of patients with PoPH in an American population of patients.

STUDY DESIGN AND METHODS

We identified PoPH patients from the Cleveland Clinic Pulmonary Hypertension Registry between 1998 and 2019. We collected prespecified data, particularly focusing on hepatic and cardiopulmonary assessments and tested their effect on long-term survival.

RESULTS

Eighty patients with PoPH with a mean ± SD age of 54 ± 10 years, (54% females) were included in the analysis. The median Model for End-Stage Liver Disease with sodium (MELD-Na) score was 13.0 (10.0-18.0) at PoPH diagnosis. World Health Association functional class III-IV was noted in 57%. Mean pulmonary arterial pressure was 47 ± 10 mmHg and pulmonary vascular resistance 6.0 ± 2.8 Woods units. A total of 63 (78.5%) patients were started on pulmonary arterial hypertension (PAH)-specific treatment during the first 6 months of diagnosis. Survival rates at 1-, 3- and 5-year were 77, 52 and 34%, respectively. Cardiopulmonary hemodynamics as well as PAH-specific treatment did not affect survival. In the multivariable model, MELD-Na, resting heart rate and the presence of hepatic encephalopathy were independent predictors of survival.

CONCLUSION

PoPH patients have poor 5-year survival which is strongly associated to the severity of underlying liver disease and not to the hemodynamic severity of PoPH; therefore efforts should be focused in facilitating liver transplantation for these patients.

Development of human alveolar epithelial cell models to study distal lung biology and disease

Many acute and chronic diseases affect the distal lung alveoli. Alveolar epithelial cell (AEC) lines are needed to better model these diseases. We used de-identified human remnant transplant lungs to develop a method to establish AEC lines. The lines grow well in 2-dimensional (2D) culture as epithelial monolayers expressing lung progenitor markers. In 3-dimensional (3D) culture with fibroblasts, Matrigel, and specific media conditions, the cells form alveolar-like organoids expressing mature AEC markers including aquaporin 5 (AQP5), G-protein-coupled receptor class C group 5 member A (GPRC5A), and surface marker HTII280. Single-cell RNA sequencing of an AEC line in 2D versus 3D culture revealed increased cellular heterogeneity and induction of cytokine and lipoprotein signaling in 3D organoids. Our approach yields lung progenitor lines that retain the ability to differentiate along the alveolar cell lineage despite long-term expansion and provides a valuable system to model and study the distal lung in vitro.

Organoids Model Transcriptional Hallmarks of Oncogenic KRAS Activation in Lung Epithelial Progenitor Cells

Mutant KRAS is a common driver in epithelial cancers. Nevertheless, molecular changes occurring early after activation of oncogenic KRAS in epithelial cells remain poorly understood. We compared transcriptional changes at single-cell resolution after KRAS activation in four sample sets. In addition to patient samples and genetically engineered mouse models, we developed organoid systems from primary mouse and human induced pluripotent stem cell-derived lung epithelial cells to model early-stage lung adenocarcinoma. In all four settings, alveolar epithelial progenitor (AT2) cells expressing oncogenic KRAS had reduced expression of mature lineage identity genes. These findings demonstrate the utility of our in vitro organoid approaches for uncovering the early consequences of oncogenic KRAS expression. This resource provides an extensive collection of datasets and describes organoid tools to study the transcriptional and proteomic changes that distinguish normal epithelial progenitor cells from early-stage lung cancer, facilitating the search for targets for KRAS-driven tumors.

FRA1 contributes to MEK-ERK pathway-dependent PD-L1 upregulation by KRAS mutation in premalignant human bronchial epithelial cells

Oncogenic KRAS mutations are frequently found in non-small cell lung carcinoma (NSCLC) and cause constitutive activation of the MEK-ERK pathway. Many cancer types have been shown to overexpress PD-L1 to escape immune surveillance. FRA1 is a MEK/ERK-dependent oncogenic transcription factor and a member of the AP-1 transcriptional factor superfamily. This study assesses the hypothesis that KRAS mutation directly regulates PD-L1 expression through the MEK-ERK pathway mediated by FRA1. Premalignant human bronchial epithelial cell (HBEC) lines harboring the KRAS mutation^V12, EGFR mutation, p53 knock-down, or both KRAS mutation and p53 knock-down were tested for levels of PD-L1, FRA1, and ERK activation (pERK). Our results showed that KRAS mutation alone, but not other genetic alterations, induced significantly higher expression of PD-L1 compared to its vector counterparts. The increased PD-L1 expression in the KRAS mutated cells was dramatically reduced by inhibition of ERK activation. Furthermore, the MEK-ERK pathway-dependent PD-L1 expression was markedly reduced by FRA1 silencing. Interestingly, FRA1 silencing led to inhibition of ERK activation, indicating that FRA1 plays a role in PD-L1 regulation via positive feedback of ERK activation. Correlation of PD-L1 and FRA1 mRNA expression was validated using human lung cancer specimens from The Cancer Genome Atlas (TCGA) and established NSCLC cell lines from Cancer Cell Line Encyclopedia (CCLE). FRA1 expression was significantly associated with PD-L1 expression, and high FRA1 expression was correlated with poor overall survival. Our findings suggest that oncogenic KRAS-driven PD-L1 expression is dependent on MEK-ERK and FRA1 in high risk, premalignant HBEC.

Lower DLco% identifies exercise pulmonary hypertension in patients with parenchymal lung disease referred for dyspnea

Exercise pulmonary hypertension is an underappreciated form of physical limitation related to early pulmonary vascular disease. A low diffusing capacity of lungs for carbon monoxide (DLco) can be seen in patients with resting pulmonary hypertension as well as parenchymal lung disease. It remains unclear whether low DLco% identifies early pulmonary vascular disease. We hypothesize that a reduced DLco% differentiates the presence of exercise pulmonary hypertension in patients with parenchymal lung disease. Fifty-six patients referred for unexplained exertional dyspnea with pulmonary function tests within six months of hemodynamic testing underwent exercise right heart catheterization. Exclusion criteria included resting pulmonary arterial or venous hypertension. Receiver operator characteristic curve determined the optimal DLco% cutoffs based on the presence or absence of parenchymal lung disease. Twenty-one (37%) patients had parenchymal lung disease, most common manifesting as chronic obstructive lung disease or interstitial lung disease. In patients with parenchymal lung disease, a DLco of 46% demonstrated 100% sensitivity and 73% specificity for detecting exercise pulmonary hypertension. In patients without parenchymal lung disease, a DLco of 73% demonstrated 58% sensitivity and 94% specificity for detecting exercise pulmonary hypertension. In both cohorts, DLco% below the optimum cutoffs were associated with higher peak mean pulmonary arterial pressure and peak total pulmonary resistance consistent with the hemodynamic definition of exercise pulmonary hypertension. Patients with a DLco < 46% were more often treated with pulmonary vasodilators and had a trend to higher mortality and lung transplant. DLco% is a simple non-invasive screening test for the presence of exercise pulmonary hypertension in our mixed referral population with progressive exertional dyspnea. DLco < 46% with parenchymal lung disease and DLco < 73% without parenchymal lung disease may play a role in differentiating the presence of pulmonary vascular disease prior to invasive hemodynamic testing.

The Immune Contexture Associates with the Genomic Landscape in Lung Adenomatous Premalignancy

Epithelial cells in the field of lung injury can give rise to distinct premalignant lesions that may bear unique genetic aberrations. A subset of these lesions may escape immune surveillance and progress to invasive cancer; however, the mutational landscape that may predict progression has not been determined. Knowledge of premalignant lesion composition and the associated microenvironment is critical for understanding tumorigenesis and the development of effective preventive and interception strategies. To identify somatic mutations and the extent of immune cell infiltration in adenomatous premalignancy and associated lung adenocarcinomas, we sequenced exomes from 41 lung cancer resection specimens, including 89 premalignant atypical adenomatous hyperplasia lesions, 15 adenocarcinomas in situ, and 55 invasive adenocarcinomas and their adjacent normal lung tissues. We defined nonsynonymous somatic mutations occurring in both premalignancy and the associated tumor as progression-associated mutations whose predicted neoantigens were highly correlated with infiltration of CD8⁺ and CD4⁺ T cells as well as upregulation of PD-L1 in premalignant lesions, suggesting the presence of an adaptive immune response to these neoantigens. Each patient had a unique repertoire of somatic mutations and associated neoantigens. Collectively, these results provide evidence for mutational heterogeneity, pathway dysregulation, and immune recognition in pulmonary premalignancy.Significance: These findings identify progression-associated somatic mutations, oncogenic pathways, and association between the mutational landscape and adaptive immune responses in adenomatous premalignancy.See related commentary by Merrick, p. 4811.

Secondary membranous nephropathy in a patient with myasthenia gravis without thymic disease, and partial remission induced by adrenocorticotropic hormone therapy

Membranous glomerulonephritis is the most common glomerular disease in adults. Its primary form has been characterized with formation of phospholipase A2 receptor antibodies. Malignancy, infections, and autoimmune disorders are the most common causes of secondary membranous glomerulonephritis. We present a case of a 55-year-old African American female who presented with nephrotic range proteinuria and diagnosed with secondary membranous glomerulonephritis based on distinct pathological features on kidney biopsy and absence of serum phospholipase A2 receptor antibodies. She initially underwent extensive workup for malignancies, infections, and common autoimmune disorders which were all negative. Her proteinuria remained resistant to steroid treatment and she was treated with subcutaneous adrenocorticotropic hormone injections. Meanwhile, she was also diagnosed with the anti-muscle specific kinase antibody variant of myasthenia gravis. In literature, there are few case reports of myasthenia gravis as a cause of secondary membranous glomerulonephritis. In our case, the lack of other inciting factors also suggested this association.

Coxiella burnetii Endocarditis and Meningitis, California, USA, 2017

The epidemiology of Coxiella burnetii infection in the United States is not well characterized. We report a case-patient with C. burnetii endocarditis and meningitis. Infection was diagnosed by detecting high serologic titers for C. burnetii and confirmed by sequencing of C. burnetii 16S rRNA isolated from resected valvular tissue and PCR of cerebrospinal fluid.

Capillary Proliferation in Systemic-Sclerosis-Related Pulmonary Fibrosis: Association with Pulmonary Hypertension

Objective

We sought to determine if any histopathologic component of the pulmonary microcirculation can distinguish systemic sclerosis (SSc)‐related pulmonary fibrosis (PF) with and without pulmonary hypertension (PH).

Methods

Two pulmonary pathologists blindly evaluated 360 histologic slides from lungs of 31 SSc‐PF explants or autopsies with (n = 22) and without (n = 9) PH. The presence of abnormal small arteries, veins, and capillaries (pulmonary microcirculation) was semiquantitatively assessed in areas of preserved lung architecture. Capillary proliferation (CP) within the alveolar walls was measured by its distribution, extent (CP % involvement), and maximum number of layers (maximum CP). These measures were then evaluated to determine the strength of their association with right heart catheterization–proven PH.

Results

Using consensus measures, all measures of CP were significantly associated with PH. Maximum CP had the strongest association with PH (P = 0.013; C statistic 0.869). Maximum CP 2 or more layers and CP % involvement 10% or greater were the optimal thresholds that predicted PH, both with a sensitivity of 56% and specificity of 91%. The CP was typically multifocal rather than focal or diffuse and was associated with a background pattern of usual interstitial pneumonia. There was a significant but weaker relationship between the presence of abnormal small arteries and veins and PH.

Conclusion

In the setting of advanced SSc‐PF, the histopathologic feature of the pulmonary microcirculation best associated with PH was capillary proliferation in architecturally preserved lung areas.

Treatment of exercise pulmonary hypertension improves pulmonary vascular distensibility

Exercise pulmonary hypertension (ePH) is an underappreciated form of exertional limitation. Despite normal resting pulmonary artery pressures, patients with ePH demonstrate early pulmonary vascular changes with reduced pulmonary arterial compliance (PAC) and vascular distensibility (α). Recent data suggest that targeted vasodilator therapy may improve hemodynamics in ePH, but it is not well-known whether such medications alter pulmonary vascular distensibility. Thus, we sought to evaluate if vasodilator therapy improved α a marker of early pulmonary vascular disease in ePH. Ten patients performed supine exercise right heart catheterization (exRHC) with bicycle ergometer to peak exercise. Patients diagnosed with ePH were treated with pulmonary vasodilators. A repeat symptom-limited exercise RHC was performed at least six months after therapy. Patients with ePH had evidence of early pulmonary vascular disease, as baseline PAC and α were reduced. After pulmonary vasodilator therapy, a number of peak exercise hemodynamics statistically improved, including a decrease of total pulmonary resistance and pulmonary vascular resistance, while cardiac output increased. Importantly, vasodilator therapy partially reversed the pathogenic decreases of α at the time of repeat exRHC. Pulmonary vascular distensibility, α, a marker of early pulmonary vascular disease, improves in ePH after therapy with pulmonary vasodilators.

Insights on pulmonary tumor thrombotic microangiopathy: a seven-patient case series

Pulmonary tumor thrombotic microangiopathy (PTTM) is a disease process wherein tumor cells are thought to embolize to the pulmonary circulation causing pulmonary hypertension (PH) and death from right heart failure. Presented herein are clinical, laboratory, radiographic, and histologic features across seven cases of PTTM. Highlighted in this publication are also involvement of pulmonary venules and clinical features distinguishing PTTM from clinical mimics.

We conducted a retrospective chart review of seven cases of PTTM from hospitals in the greater Los Angeles metropolitan area.

Patients in this series exhibited: symptoms of cough and progressive dyspnea; PH and/or heart failure on physical exam; laboratory abnormalities of anemia, thrombocytopenia, elevated LDH, and elevated D-dimer; chest computed tomography (CT) showing diffuse septal thickening, mediastinal and hilar lymphadenopathy and nodules; elevated pulmonary artery pressures on transthoracic echocardiogram and/or right heart catheterization; and presence of malignancy. Tumor emboli and fibrocellular intimal proliferation were seen in pulmonary arterioles, while two patients had pulmonary venopathy.

PTTM is a devastating disease occurring in patients with metastatic carcinoma. An early diagnosis is challenging. Understanding the clinical presentation of PTTM and distinguishing PTTM from clinical mimics may help achieve an early diagnosis and allow time for initiation of treatment.

Phase I Trial of Intratumoral Injection of CCL21 Gene-Modified Dendritic Cells in Lung Cancer Elicits Tumor-Specific Immune Responses and CD8+ T-cell Infiltration

Purpose: A phase I study was conducted to determine safety, clinical efficacy, and antitumor immune responses in patients with advanced non-small cell lung carcinoma (NSCLC) following intratumoral administration of autologous dendritic cells (DC) transduced with an adenoviral (Ad) vector expressing the CCL21 gene (Ad-CCL21-DC). We evaluated safety and tumor antigen-specific immune responses following in situ vaccination (ClinicalTrials.gov: NCT01574222).Experimental Design: Sixteen stage IIIB/IV NSCLC subjects received two vaccinations (1 × 10⁶, 5 × 10⁶, 1 × 10⁷, or 3 × 10⁷ DCs/injection) by CT- or bronchoscopic-guided intratumoral injections (days 0 and 7). Immune responses were assessed by tumor antigen-specific peripheral blood lymphocyte induction of IFNγ in ELISPOT assays. Tumor biopsies were evaluated for CD8⁺ T cells by IHC and for PD-L1 expression by IHC and real-time PCR (RT-PCR).Results: Twenty-five percent (4/16) of patients had stable disease at day 56. Median survival was 3.9 months. ELISPOT assays revealed 6 of 16 patients had systemic responses against tumor-associated antigens (TAA). Tumor CD8⁺ T-cell infiltration was induced in 54% of subjects (7/13; 3.4-fold average increase in the number of CD8⁺ T cells per mm²). Patients with increased CD8⁺ T cells following vaccination showed significantly increased PD-L1 mRNA expression.Conclusions: Intratumoral vaccination with Ad-CCL21-DC resulted in (i) induction of systemic tumor antigen-specific immune responses; (ii) enhanced tumor CD8⁺ T-cell infiltration; and (iii) increased tumor PD-L1 expression. Future studies will evaluate the role of combination therapies with PD-1/PD-L1 checkpoint inhibition combined with DC-CCL21 in situ vaccination. Clin Cancer Res; 23(16); 4556-68. ©2017 AACR.

European Society of Coloproctology consensus on the surgical management of intestinal failure in adults

Intestinal failure (IF) is a debilitating condition of inadequate nutrition due to an anatomical and/or physiological deficit of the intestine. Surgical management of patients with acute and chronic IF requires expertise to deal with technical challenges and make correct decisions. Dedicated IF units have expertise in patient selection, operative risk assessment and multidisciplinary support such as nutritional input and interventional radiology, which dramatically improve the morbidity and mortality of this complex condition and can beneficially affect the continuing dependence on parenteral nutritional support. Currently there is little guidance to bridge the gap between general surgeons and specialist IF surgeons. Fifteen European experts took part in a consensus process to develop guidance to support surgeons in the management of patients with IF. Based on a systematic literature review, statements were prepared for a modified Delphi process. The evidence for each statement was graded using Oxford Centre for Evidence-Based Medicine Levels of Evidence. The current paper contains the statements reflecting the position and practice of leading European experts in IF encompassing the general definition of IF surgery and organization of an IF unit, strategies to prevent IF, management of acute IF, management of wound, fistula and stoma, rehabilitation, intestinal and abdominal reconstruction, criteria for referral to a specialist unit and intestinal transplantation.

Leukocyte chemotactic factor 2 (LECT2) amyloidosis presenting as pulmonary-renal syndrome: a case report and review of the literature

Leukocyte chemotactic factor-2 (LECT2) amyloidosis has been described as being associated with kidney disease; however, no clinical manifestations outside of the kidney have been previously reported. We describe a patient presenting with pulmonary-renal syndrome found to have deposition of amyloidogenic LECT2 (ALECT2) within both the lung and the kidney. This case is unique in regard to both the patient's clinical presentation of pulmonary-renal syndrome in the setting of amyloidosis and the biopsy finding of ALECT2 deposition within the lung. It also emphasizes the importance of tissue diagnosis in such cases, given that amyloidosis was not initially considered in the differential diagnosis.

Dynamic changes in intracellular ROS levels regulate airway basal stem cell homeostasis through Nrf2-dependent Notch signaling

Airways are exposed to myriad environmental and damaging agents such as reactive oxygen species (ROS), which also have physiological roles as signaling molecules that regulate stem cell function. However, the functional significance of both steady and dynamically changing ROS levels in different stem cell populations, as well as downstream mechanisms that integrate ROS sensing into decisions regarding stem cell homeostasis, are unclear. Here, we show in mouse and human airway basal stem cells (ABSCs) that intracellular flux from low to moderate ROS levels is required for stem cell self-renewal and proliferation. Changing ROS levels activate Nrf2, which activates the Notch pathway to stimulate ABSC self-renewal and an antioxidant program that scavenges intracellular ROS, returning overall ROS levels to a low state to maintain homeostatic balance. This redox-mediated regulation of lung stem cell function has significant implications for stem cell biology, repair of lung injuries, and diseases such as cancer.

Banff 2013 meeting report: inclusion of c4d-negative antibody-mediated rejection and antibody-associated arterial lesions

The 12th Banff Conference on Allograft Pathology was held in Comandatuba, Brazil, from August 19-23, 2013, and was preceded by a 2-day Latin American Symposium on Transplant Immunobiology and Immunopathology. The meeting was highlighted by the presentation of the findings of several working groups formed at the 2009 and 2011 Banff meetings to: (1) establish consensus criteria for diagnosing antibody-mediated rejection (ABMR) in the presence and absence of detectable C4d deposition; (2) develop consensus definitions and thresholds for glomerulitis (g score) and chronic glomerulopathy (cg score), associated with improved inter-observer agreement and correlation with clinical, molecular and serological data; (3) determine whether isolated lesions of intimal arteritis ("isolated v") represent acute rejection similar to intimal arteritis in the presence of tubulointerstitial inflammation; (4) compare different methodologies for evaluating interstitial fibrosis and for performing/evaluating implantation biopsies of renal allografts with regard to reproducibility and prediction of subsequent graft function; and (5) define clinically and prognostically significant morphologic criteria for subclassifying polyoma virus nephropathy. The key outcome of the 2013 conference is defining criteria for diagnosis of C4d-negative ABMR and respective modification of the Banff classification. In addition, three new Banff Working Groups were initiated.

A century of abdominoperineal excision for rectal cancer

SUMMARY Abdominoperineal excision (APE) for rectal cancer was described by Miles over 100 years ago. The technique and approach have undergone a number of modifications, however, the essence of the procedure remains essentially unchanged. Management of rectal cancer has changed significantly over the century as surgery and adjuvant therapies have evolved, with improved outcome and a marked decline in incidence of APE. It has been widely recognized that tumors requiring APE are associated with higher rates of local recurrence and positive resection margins compared with anterior resection. The modern challenge remains in obtaining oncological equivalence for both procedures. This article reviews the history and evolution of APE, assesses its current status and explores modern perspectives on optimizing the surgical approach.

Acute rejection associated with donor-specific anti-MICA antibody in a highly sensitized pediatric renal transplant recipient

Allograft rejection in HLA identical transplant recipients and in patients without detectable donor-specific anti-HLA antibodies has lead to the identification of non-HLA antigens as targets of the alloimmune response. MICA antigen has been recognized as an important non-HLA target in renal transplantation. Recent studies have shown that anti-MICA antibodies are associated with acute renal allograft rejection and failure. Current cross match procedures using donor lymphocytes fail to detect MICA antibodies. Transplant candidates are not routinely tested for pre-sensitization to MICA antigens nor are transplant donors typed for MICA alleles. Optimal classification and treatment of acute rejection associated with MICA antibody remains unknown. In this case report, we are the first to describe the clinical course and treatment of donor-specific MICA antibody associated with both Banff type II A ACR and AMR in a highly sensitized pediatric renal re-transplant recipient. This case also emphasizes the importance of pre-transplant screening for donor-specific MICA antibody especially in highly sensitized renal transplant patients.

Significance of intragraft CD138+ lymphocytes and p-S6RP in pediatric kidney transplant biopsies

BACKGROUND

We have previously shown that intragraft CD20+ B cells are associated with acute cellular rejection (ACR) and allograft loss. Phosphorylation of S6 ribosomal protein, a downstream target of the PI3K/Akt/mTOR pathway, promotes growth and proliferation of cells and could identify metabolically active cells such as alloantibody secreting plasma cells. Because CD20+ lymphocytes can differentiate into CD138+ plasma cells, we aimed to identify functionally active plasma cells by using intragraft CD138 quantification and p-S6RP staining and correlate these results with allograft rejection, function, and survival.

METHODS

We examined 46 renal transplant biopsies from 32 pediatric patients who were biopsied for clinical suspicion of rejection. Immunohistochemical staining for C4d, CD20, CD138, and p-S6RP was performed. Patient creatinine clearance and graft status was followed up postbiopsy.

RESULTS

Patients with greater than or equal to six CD138+ cells/high power field (hpf) had worse graft survival with a hazard ratio of 3.4 (95% CI 1.3-9.2) 2 years postbiopsy compared with those with 0 to 5 cells/hpf (P=0.016). CD138+ cells were stained for p-S6RP, indicating functionally active plasma cells. They were associated with ACR (P=0.004) and deteriorating graft function (R=0.22, P=0.001). Intragraft CD20+ and CD138+ cells found together in ACR were associated with poorer graft survival than either marker alone, hazard ratio 1.5 (95% CI 1.1-2.2, P=0.01).

CONCLUSIONS

A threshold of greater than or equal to six CD138+ metabolically active plasma cells per hpf, coexisting with CD20+ B cells, was associated with poor allograft function and survival. This may represent an additional antibody-mediated process present in the setting of ACR and could play an important role in characterization and treatment of transplant rejection.

Surgical management of endobronchial solitary fibrous tumors

Solitary fibrous tumors of the pleura are rare neoplasms with both benign and malignant behaviors that are not reliably predicted by histologic findings. We report the case of a 55-year-old woman with recurrent pneumonias whose left mainstem bronchus was occluded by a 2.1- x 1.4-cm endobronchial mass that extended extraluminally into the subcarina. The mass was tissue diagnosed to be a solitary fibrous tumor preoperatively, and was completely resected by sleeve resection of the left mainstem bronchus with lung preservation. This report describes the challenging surgical management of an infrequently encountered tumor in a unique location.

Presence of a putative tumor-initiating progenitor cell population predicts poor prognosis in smokers with non-small cell lung cancer

Smoking is the most important known risk factor for the development of lung cancer. Tobacco exposure results in chronic inflammation, tissue injury, and repair. A recent hypothesis argues for a stem/progenitor cell involved in airway epithelial repair that may be a tumor-initiating cell in lung cancer and which may be associated with recurrence and metastasis. We used immunostaining, quantitative real-time PCR, Western blots, and lung cancer tissue microarrays to identify subpopulations of airway epithelial stem/progenitor cells under steady-state conditions, normal repair, aberrant repair with premalignant lesions and lung cancer, and their correlation with injury and prognosis. We identified a population of keratin 14 (K14)-expressing progenitor epithelial cells that was involved in repair after injury. Dysregulated repair resulted in the persistence of K14+ cells in the airway epithelium in potentially premalignant lesions. The presence of K14+ progenitor airway epithelial cells in NSCLC predicted a poor prognosis, and this predictive value was strongest in smokers, in which it also correlated with metastasis. This suggests that reparative K14+ progenitor cells may be tumor-initiating cells in this subgroup of smokers with NSCLC.

Abstract 4299: Poor prognosis in smokers with non-small cell lung cancer correlates with the presence of a reparative progenitor cell population

Cigarette smoking is the most significant risk factor for the initiation and development of lung cancer. Tobacco exposure often results in chronic inflammation, tissue injury, and airway repair. A recent hypothesis demonstrates the presence of a stem/progenitor cell population that involved in airway epithelial repair. These cells may be tumor-initiating cells in lung cancer, and subsequently may be involved in tumor recurrence and metastasis. In the airway epithelium, cells that express keratin (K) 5 and its intermediate filament binding partner K14 are considered to be progenitor cells in the adult large airways at steady state and during airway epithelial repair.

In order to identify subpopulations of airway epithelial stem/progenitor cells under steady state conditions, normal repair, aberrant repair with premalignant lesions, and lung cancer, and their respective correlation with injury and prognosis, we used immunostaining on mouse and human lung tissues, along with a human lung cancer tissue microarray. We found K5 and K14 expression in the steady state submucosal glands and gland ducts. In the basal layer of normal airway pseudostratified columnar epithelium, only K5 expression was prominent while K14 expression was absent. In a heterotopic, syngeneic, murine tracheal transplant model of repairing airway epithelium, we identified a population of K14+ progenitor epithelial cells that was temporally involved in normal repair after injury. Dysregulated repair resulted in persistence of K14+ cells in the airway epithelium of premalignant lesions.

In human patients (n = 399), the presence of K14+ cells in non-small cell lung cancer (NSCLC) predicted poorer outcomes (P = 0.004) especially in patients who are smokers (P = 0.001). The predictive value was more pronounced in current smokers (P = 0.01) compared to former smokers (P = 0.04). In never smokers, the presence of K14+ cells had no predictive value for outcome. We found that the presence of K14+ cells in the primary tumors of current smokers was associated with metastatic disease (P = 0.02). We further found that non-adenocarcinoma NSCLCs from current smokers with metastases had a higher percentage of K14+ cells in the primary tumor sites. (P = 0.004). Examination of K14 expression in distant metastatic sites revealed a significant increase in the number of K14-expressing cells in metastases compared to the primary sites in squamous lung cancer, but not in other histologic subtypes.

Our data propose that dysregulated repair after injury leads to a self-renewing K14+ progenitor cell population in premalignant lesions. The presence of K14+ progenitor airway epithelial cells in NSCLC predicted a poor prognosis with the strongest predictive value in smokers, where it correlated with metastasis. This suggests that reparative K14+ progenitor cells are the putative tumor-initiating cells in this subgroup of smokers with NSCLC.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 4299.

Death from metastatic donor-derived ovarian cancer in a male kidney transplant recipient

Posttransplant malignancy developing in an allograft is an uncommon complication of organ transplantation. The tumor may represent malignant transformation of donor or recipient cells that were previously normal, metastatic malignancy of recipient origin or malignancy transmitted from organ donor to recipient. Establishing the origin of the malignancy is critical to treatment algorithms. It is generally believed allograft removal and immunosuppression withdrawal will lead to resolution of transmitted malignancies in cases where the renal allograft is the origin. We report a male patient who developed metastatic ovarian malignancy secondary to donor transmission.

CD20+ Lymphocytes in Renal Allografts Are Associated with Poor Graft Survival in Pediatric Patients

BACKGROUND

The presence of CD20+ lymphocyte renal allograft infiltrates has been associated with steroid-resistant rejection and poor graft survival. We quantified the number of CD20+ lymphocytes in renal allograft biopsies and correlated the results with graft survival. We also determined the relationships between CD20+ lymphocytes and acute cellular rejection versus antibody-mediated rejection.

METHODS

We examined 45 biopsy samples from 31 pediatric patients biopsied for suspicion of rejection from November 2001 to November 2004. Immunohistochemical staining for CD20 and C4d was performed on all biopsies; CD20+ cell density per high-power field (hpf) was determined for each core. Patient graft status was followed postbiopsy and documented for graft survival or failure using the cutoff date of December 31, 2005.

RESULTS

Patients with 2-10 and 11-100 CD20+ cells/hpf had worse graft survival in Kaplan-Meier analysis with a hazard ratio 4.56 (CI 1.07-19.35) two years postbiopsy compared to those with 0-1 cells/hpf (P = 0.02). The presence of CD20+ lymphocytes was significantly associated with acute cellular rejection (P = 0.0001) and not associated with antibody-mediated rejection (P = 0.16). Receiver-operating curve analysis confirmed > or =3 cells/hpf correlating with acute cellular rejection, yielding sensitivity 90% and specificity 76%.

CONCLUSIONS

This study shows a significant 4.5-fold risk of graft failure at two years postbiopsy with presence of > or =2 CD20+ cells/hpf. Moreover, > or =3 CD20+ lymphocytes were highly associated with acute cellular rejection. They may be functioning as professional antigen-presenting cells in the graft. In steroid-refractory cellular rejections, therapies that target B cells may prolong graft survival.

Phosphorylated S6 ribosomal protein: a novel biomarker of antibody-mediated rejection in heart allografts

We tested the hypothesis that phosphorylation of S6 ribosomal protein (S6RP), a downstream target of the PI3K/Akt/mTOR pathway, is a biomarker of antibody-mediated rejection (AMR) in heart allografts. Primary cultures of human aortic and microvascular endothelial cells (EC) were treated with anti-HLA class I and class II antibodies (Ab) and cell lysates were studied for phosphorylation of S6 ribosmal protein at Serine235/236 (p-S6RP). Treatment of cultured EC with anti-class I and class II Ab stimulated S6RP phosphorylation. Immunohistochemical techniques were used to detect the level of p-S6RP in endomyocardial biopsies (n = 131) from 46 heart transplant recipients and the results were correlated with histopathological diagnosis of rejection, C4d staining, production of posttransplant anti-HLA Ab and clinical outcome. Increased phosphorylation of S6RP in endomyocardial biopsies was significantly associated with the diagnosis of AMR (p < 0.0001). No significant association between acute cellular rejection (ACR) and p-S6RP was observed. C4d staining was positively associated with both AMR and p-S6RP. Posttransplant anti-HLA class II Ab production was also significantly associated with a positive p-S6RP status in cardiac biopsies. These results indicate that p-S6RP is a useful biomarker for the diagnosis of AMR.

Predictors and risk factors for recurrent scleroderma renal crisis in the kidney allograft: case report and review of the literature

Scleroderma renal crisis (SRC) can lead to end-stage renal disease (ESRD) and subsequent need for dialysis and/or renal transplantation. We review all reported cases of renal transplantations in scleroderma patients from PubMed search, present UNOS data on transplant outcomes, and identify predictors for allograft SRC. Of the five cases with recurrent SRC, all developed ESRD within a year of onset of native kidney SRC, whereas none of those who developed ESRD more than 1-2 years after the onset of SRC developed recurrence. Anemia preceded allograft SRC in two cases, pericardial effusion in one, and skin tightening in two others. UNOS data (October 1987-July 2004) documented 260 transplants performed for the renal diagnosis of scleroderma, with a 5-year graft survival rate of 56.7%. The risk for allograft SRC recurrence appears to correlate with early native renal function loss following the onset of SRC. Recurrent SRC in the allograft may be heralded by multiple clinical markers known to be predictive of severe scleroderma, including progression of diffuse skin thickening, new-onset anemia and cardiac complications.

Pseudocyst formation in gastric ectopic pancreas

CONTEXT

It is rare for ectopic pancreatic tissue to cause symptoms or require treatment, however diseases of normal pancreas may also occur in ectopic pancreas tissue.

CASE REPORT

This report describes the clinical, endoscopic, radiologic and histologic features of a pseudocyst occurring in gastric ectopic pancreas in a 19-year-old man. The difficulty and implications of making an accurate pre-operative diagnosis are highlighted.

CONCLUSION

Ectopic pancreatic tissue, although rare, should be considered in the differential diagnosis of a submucosal gastric mass.

A parathyroid hormone-related protein-secreting metastatic epithelioid leiomyosarcoma. A case report and review of the literature

A diagnosis of parathyroid hormone-related protein (PTH-rP)-secreting metastatic uterine epithelioid leiomyosarcoma was made in a 61-year-old woman with humoral hypercalcemia of malignancy. A primary uterine tumor had been removed 10 years previously, which had been associated with a short history of hypercalcemia. The original uterine tumor was diagnosed as a smooth muscle tumor of uncertain malignant potential. To the best of our knowledge, this is the first reported case of a PTH-rP-secreting uterine leiomyosarcoma. We demonstrate the dramatic changes in serum calcium, phosphorus, PTH, and PTH-rP levels after tumor resection. Extensive biochemical analysis and detailed immunohistochemical and ultrastructural characterization demonstrate several features of this tumor.

Instrumentation for monitoring gas exchange and metabolic rate in critically ill patients

In the critically ill patient the monitoring of oxygen consumption (VO2) and carbon dioxide production (VCO2) can identify abnormalities in tissue perfusion and metabolism. A patient's metabolic utilization can be calculated by indirect calorimetry, once VO2 and VCO2 are measured. This paper evaluates a compact instrument designed for monitoring VO2 and VCO2 in the critically ill adult. Accuracy was measured under controlled laboratory conditions using oxygen-enriched air, PEEP, and intermittent mandatory ventilation (IMV). Accuracy averaged 1.3% for VO2 and 0.9% for VCO2 when room air was used. Accuracy was 11.7% for VO2 and 6.8% for VCO2 when 80% oxygen was used. PEEP of 30 cm H2O had little effect on accuracy. IMV at 2 breath/min (room air) resulted in an accuracy of 4.0% and 4.1% for VO2 and VCO2, respectively.

Blood-gas analyzer calibration and quality control using a precision gas-mixing instrument

We describe a new instrument that performs on-site mixing of oxygen (O2), carbon dioxide (CO2), and nitrogen (N2) to create compositions that can replace gases from standard premixed cylinders. This instrument yields accurate and predictable gas mixtures that can be used for two-point gas calibration of blood gas/pH analyzers or for liquid tonometry of either an aqueous buffer or blood used as quality-control material on blood-gas electrodes. The desired mixture of O2, CO2, and N2 is produced by microprocessor control of the sequential open-times on three solenoid valves that meter these pure gases through a common small-bore orifice. Any combination of O2 and CO2 can be chosen by dialing the front panel thumbwheels and pressing a button. Gas chromatographic evaluation of this gas-mixing instrument demonstrates its accuracy and precision to be better than +/- 0.1% absolute full scale for O2, CO2, and N2, making this instrument calibration and tonometry.

New gas-liquid equilibration method: syringe tonometer

This new apparatus for gas-liquid equilibration (tonometry) in a transportable vessel is designed for tonometry of blood or buffer solution in a specially designed syringe. Gas enters the syringe chamber through small holes in the tip of the syringe plunger and bubbles upward through the sample. The syringe plunger is a second chamber, which is used for warming and humidifying the gas before it enters the tonometer chamber. The entire syringe is housed in a transparent, temperature-controlled environment during equilibration. After equilibration, the sample is easily entered into a blood-gas analyzer. At most, gas-liquid O2/CO2 equilibration for 2.5 mL of buffer or blood requires less than 13 min. Comparisons with a standard thin-film tonometer show good agreement for pO2 and pCO2 over the range 0-93 kPa (0-700 mmHg) and 2-20 kPa (14-150 mmHg), respectively. The syringe tonometer eliminates contamination of the sample during transfer and transport to the analyzer, thus making tonometry more technique-independent. The apparatus is simple and easy to use, with definite advantages over existing methods of tonometry.

New gas-liquid equilibration method: syringe tonometer

This new apparatus for gas-liquid equilibration (tonometry) in a transportable vessel is designed for tonometry of blood or buffer solution in a specially designed syringe. Gas enters the syringe chamber through small holes in the tip of the syringe plunger and bubbles upward through the sample. The syringe plunger is a second chamber, which is used for warming and humidifying the gas before it enters the tonometer chamber. The entire syringe is housed in a transparent, temperature-controlled environment during equilibration. After equilibration, the sample is easily entered into a blood-gas analyzer. At most, gas-liquid O2/CO2 equilibration for 2.5 mL of buffer or blood requires less than 13 min. Comparisons with a standard thin-film tonometer show good agreement for pO2 and pCO2 over the range 0-93 kPa (0-700 mmHg) and 2-20 kPa (14-150 mmHg), respectively. The syringe tonometer eliminates contamination of the sample during transfer and transport to the analyzer, thus making tonometry more technique-independent. The apparatus is simple and easy to use, with definite advantages over existing methods of tonometry.