Protein expression of transmembrane protease serine 4 in the gastrointestinal tract and in healthy, cancer, and SARS­CoV­2 infected lungs.

In addition to the angiotensin­converting enzyme 2 (ACE2), a number of host cell entry mediators have been identified for severe acute respiratory syndrome coronavirus­2 (SARS­CoV­2), including transmembrane protease serine 4 (TMPRSS4). The authors have recently demonstrated the upregulation of TMPRSS4 in 11 different cancers, as well as its specific expression within the central nervous system using in silico tools. The present study aimed to expand the initial observations and, using immunohistochemistry, TMPRSS4 protein expression in the gastrointestinal (GI) tract and lungs was further mapped. Immunohistochemistry was performed on tissue arrays and lung tissues of patients with non­small cell lung cancer with concurrent coronavirus disease 2019 (COVID­19) infection using TMPRSS4 antibody. The results revealed that TMPRSS4 was abundantly expressed in the oesophagus, stomach, small intestine, jejunum, ileum, colon, liver and pancreas. Moreover, the extensive TMPRSS4 protein expression in the lungs of a deceased patient with COVID­19 with chronic obstructive pulmonary disease and bronchial carcinoma, as well in the adjacent normal tissue, was demonstrated for the first time, at least to the best of our knowledge. On the whole, the immunohistochemistry data of the present study suggest that TMPRSS4 may be implicated in the broader (pulmonary and extra­pulmonary) COVID­19 symptomatology; thus, it may be responsible for the tropism of this coronavirus both in the GI tract and lungs.

Erratum: On the role of artificial intelligence in medical imaging of COVID-19.

[This corrects the article DOI: 10.1016/j.patter.2021.100269.].

On the role of artificial intelligence in medical imaging of COVID-19.

Although a plethora of research articles on AI methods on COVID-19 medical imaging are published, their clinical value remains unclear. We conducted the largest systematic review of the literature addressing the utility of AI in imaging for COVID-19 patient care. By keyword searches on PubMed and preprint servers throughout 2020, we identified 463 manuscripts and performed a systematic meta-analysis to assess their technical merit and clinical relevance. Our analysis evidences a significant disparity between clinical and AI communities, in the focus on both imaging modalities (AI experts neglected CT and ultrasound, favoring X-ray) and performed tasks (71.9% of AI papers centered on diagnosis). The vast majority of manuscripts were found to be deficient regarding potential use in clinical practice, but 2.7% (n = 12) publications were assigned a high maturity level and are summarized in greater detail. We provide an itemized discussion of the challenges in developing clinically relevant AI solutions with recommendations and remedies.

COVID­19 and SARS­CoV­2 host cell entry mediators: Expression profiling of TMRSS4 in health and disease.

Severe acute respiratory syndrome (SARS) coronavirus­2 (SARS­CoV­2), the causative viral agent for the ongoing COVID­19 pandemic, enters its host cells primarily via the binding of the SARS­CoV­2 spike (S) proteins to the angiotensin­converting enzyme 2 (ACE2). A number of other cell entry mediators have also been identified, including neuropilin­1 (NRP1) and transmembrane protease serine 2 (TMPRSS2). More recently, it has been demonstrated that transmembrane protease serine 4 (TMPRSS4) along with TMPRSS2 activate the SARS­CoV­2 S proteins, and enhance the viral infection of human small intestinal enterocytes. To date, a systematic analysis of TMPRSS4 in health and disease is lacking. In the present study, using in silico tools, the gene expression and genetic alteration of TMPRSS4 were analysed across numerous tumours and compared to controls. The observations were also expanded to the level of the central nervous system (CNS). The findings revealed that TMPRSS4 was overexpressed in 11 types of cancer, including lung adenocarcinoma, lung squamous cell carcinoma, cervical squamous cell carcinoma, thyroid carcinoma, ovarian cancer, cancer of the rectum, pancreatic cancer, colon and stomach adenocarcinoma, uterine carcinosarcoma and uterine corpus endometrial carcinoma, whilst it was significantly downregulated in kidney carcinomas, acute myeloid leukaemia, skin cutaneous melanoma and testicular germ cell tumours. Finally, a high TMPRSS4 expression was documented in the olfactory tubercle, paraolfactory gyrus and frontal operculum, all brain regions which are associated with the sense of smell and taste. Collectively, these data suggest that TMPRSS4 may play a role in COVID­19 symptomatology as another SARS­CoV­2 host cell entry mediator responsible for the tropism of this coronavirus both in the periphery and the CNS.

Presence of pleomorphic features but not growth patterns improves prognostic stratification of epithelioid malignant pleural mesothelioma by 2-tier nuclear grade.

AIMS: Nuclear grade has been recently validated as a powerful prognostic tool in epithelioid malignant pleural mesothelioma (E-MPM). In other studies histological parameters including pleomorphic features and growth patterns were also shown to exert prognostic impact. The primary aims of our study are (i) externally validate the prognostic role of pleomorphic features in E-MPM and (ii) investigate if evaluating growth pattern in addition to 2-tier nuclear grade improves prognostication. METHODS AND RESULTS: 614 consecutive cases of E-MPM from our institution over a period of 15 years were retrospectively reviewed, of which 51 showed pleomorphic features. E-MPM with pleomorphic features showed significantly worse overall survival compared to those without (5.4 versus 14.7 months). Tumours with predominantly micropapillary pattern showed the worst survival (6.2 months) followed by solid (10.5 months), microcystic (15.3 months), discohesive (16.1 months), trabecular (17.6 months) and tubulo-papillary (18.6 months). Sub-classification of growth patterns into high grade (solid, micropapillary) and low grade (all others) led to good separation of overall survival (10.5 versus 18.0 months) but did not predict survival independent of 2-tier nuclear grade. A composite score comprised of growth pattern and 2-tier nuclear grade did not improve prognostication compared with nuclear grade alone. Intra-tumoural heterogeneity in growth patterns is ubiquitous. CONCLUSIONS: Our findings support the incorporation of E-MPM with pleomorphic features in the epithelioid subtype as a highly aggressive variant distinct from 2-tier nuclear grade. E-MPM demonstrates extensive heterogeneity in growth pattern but its evaluation does not offer additional prognostic utility to 2-tier nuclear grade.

Utility of Nuclear Grading System in Epithelioid Malignant Pleural Mesothelioma in Biopsy-heavy Setting: An External Validation Study of 563 Cases.

Nuclear grading systems for epithelioid malignant pleural mesothelioma (MPM) have been proposed but it remains uncertain if they could be applied in a biopsy-heavy setting. Using the proposed system, we conducted an independent, external validation study using 563 consecutive cases of epithelioid MPM diagnosed at our institution between 2003 and 2017, of which 87% of patients underwent biopsies only. The median number of sites sampled was 1, with a median maximum tissue dimension of 17 mm (biopsy) and 150 mm (resection). The median overall survival (OS) was 14.7 months. The frequencies of grade I, II, and III tumors were 31% (132/563), 52% (292/563), and 17% (94/563). Grade I tumors were associated with the most favorable median OS (24.7 mo) followed by grades II (12.7 mo) and III (7.2 mo). The 2-tier nuclear grade separated tumors into low grade (19.3 mo) and high grade (8.9 mo). In multivariate analysis, 3-tier nuclear grade, 2-tier nuclear grade, and mitosis-necrosis score predicted OS independent of age, procedural type, solid-predominant growth pattern, necrosis, and atypical mitosis (all P<0.001 except 2-tier nuclear grade, P=0.001). In the scenario of a single- site biopsy with tissue dimension ≤10 mm, none but age (P=0.002) were independently predictive. Our data also suggested sampling 3 sites or a maximum tissue dimension of at least 20 mm from a single site is optimal for nuclear grade assessment. In conclusion our study confirmed the utility of nuclear grade in epithelioid MPM using a biopsy-heavy cohort provided the tissue sample met minimum dimensional criteria.

Restrictive allograft syndrome and idiopathic pleuroparenchymal fibroelastosis: do they really have the same histology?

AIMS: Restrictive allograft syndrome (RAS) and idiopathic pleuroparenchymal fibroelastosis (IPPFE) are two different diseases reported to share the same histology. RAS relates to chronic allograft dysfunction in lung transplantation, with IPPFE being a rare condition in native lungs. Our aim is to compare their histologies alongside biopsies of usual interstitial pneumonia (UIP), to determine if there are differences that might help to elucidate the pathogenesis. METHODS AND RESULTS: We selected four postmortem allograft lungs from patients who developed a clear clinical RAS pattern, five biopsies diagnosed as IPPFE, five UIP biopsies and five sections of normal lung. Histopathological features were described without knowledge of clinical and radiological features. Both RAS allografts and IPPFE biopsies showed intra-alveolar fibrosis and elastosis (IAFE), but RAS allografts also showed concomitant obliterative bronchiolitis, vascular lymphoplasmacytic inflammation within fibrointimal thickening, less fibroblastic foci (FF) at the advancing edge of the fibrosis (one against 14.4 FF in 2 mm2 ) and a slight reduction of the capillary network compared to UIP (P = 0.07) and controls (P = 0.06). The main differences seen in UIP were the lack of IAFE and the presence of honeycomb change. CONCLUSIONS: RAS and PPFE histopathology both show IAFE, but display various differences, particularly in their vascular morphology that may allow further understanding of pathogenesis.

Repeated measurements of NT-pro-B-type natriuretic peptide, troponin T or C-reactive protein do not predict future allograft rejection in heart transplant recipients.

BACKGROUND: Studies on the prognostic value of serial biomarker assays for future occurrence of allograft rejection (AR) are scarce. We examined whether repeated measurements of NT-pro-B-type natriuretic peptide (NT-proBNP), troponin T (TropT) and C-reactive protein (CRP) predict AR. METHODS: From 2005 to 2010, 77 consecutive heart transplantation (HTx) recipients were included. The NT-proBNP, TropT, and CRP were measured at 16 ± 4 (mean ± standard deviation) consecutive routine endomyocardial biopsy surveillance visits during the first year of follow-up. Allograft rejection was defined as International Society for Heart and Lung Transplantation (ISHLT) grade 2R or higher at endomyocardial biopsy. Joint modeling was used to assess the association between repeated biomarker measurements and occurrence of future AR. Joint modeling accounts for dependence among repeated observations in individual patients. RESULTS: The mean age of the patients at HTx was 49 ± 9.2 years, and 68% were men. During the first year of follow-up, 1,136 biopsies and concurrent blood samples were obtained, and 56 patients (73%) experienced at least one episode of AR. All biomarkers were elevated directly after HTx and achieved steady-state after ∼ 12 weeks, both in patients with or without AR. No associations were present between the repeated measurements of NT-proBNP, TropT, or CRP and AR both early (weeks 0-12) and late (weeks 13-52) in the course after HTx (hazard ratios for weeks 13-52: 0.96 (95% confidence interval, 0.55-1.68), 0.67 (0.27-1.69), and 1.44 (0.90-2.30), respectively, per ln[unit]). Combining the three biomarkers in one model also rendered null results. CONCLUSION: The temporal evolution of NT-proBNP, TropT, and CRP before AR did not predict occurrence of acute AR both in the early and late course of the first year after HTx.

Post-mortem tissue biopsies obtained at minimally invasive autopsy: an RNA-quality analysis.

INTRODUCTION: Bereaved relatives often refuse to give consent for post-mortem investigation of deceased cancer patients, mainly because of the mutilation due to conventional autopsy (CA). Minimally invasive autopsy (MIA) may be a more acceptable alternative and, if implemented in clinical practice, creates an opportunity to more often obtain post-mortem tissue samples of (recurred) primary tumors and metastases for molecular research. As a measure for tissue quality for molecular studies, we hereby present a feasibility study, comparing the RNA quality of MIA and CA samples, and fresh frozen samples as reference. MATERIALS AND METHODS: Tissue samples of heart, liver and kidney were prospectively collected from 24 MIAs followed by CA, and compared to corresponding archival fresh frozen tissue. After RNA isolation and RT-qPCR, RNA integrity numbers (RIN) and GAPDH expression (six amplicon sizes ranging from 71 to 530 base pairs) were measured. RIN values and GAPDH Cq values were analyzed and compared between all sample groups and post-mortem intervals (PMI). RESULTS: RIN values in MIA samples were significantly higher than those in CA samples. GAPDH was expressed significantly higher in MIA samples than in CA samples and 530 bp PCR products could be measured in all cases. GAPDH expression was significantly lower in samples with PMI >15 hours. As expected, the samples of the fresh frozen reference standard performed best in all analyses. CONCLUSION: MIA samples showed better RNA quality than CA samples, probably due to shorter PMI. Both had lower RNA quality and expression levels than fresh frozen tissue, however, remaining GAPDH RNA was still sufficiently intact. Therefore, other highly expressed genes are most likely also detectable. Gene array analysis should be performed to gain insight into the quality of entire post-mortem genomes. Reducing PMI will further improve the feasibility of demanding molecular research on post-mortem tissues, this is most likely more feasible with MIA than CA.