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Background & Aims Little is known about the composition of intrahepatic immune cells and their contribution to the pathogenesis of primary sclerosing cholangitis (PSC). Herein, we aimed to create an atlas of intrahepatic T cells and thereby perform an in-depth characterization of T cells in inflamed human liver. Methods Different single-cell RNA sequencing methods were combined with in silico analyses on intrahepatic and peripheral T cells from patients with PSC (n = 11) and healthy donors (HDs, n = 4). Multi-parameter flow cytometry and functional in vitro experiments were conducted on samples from patients with PSC (n = 24), controls with other liver diseases and HDs. Results We identified a population of intrahepatic naive-like CD4+ T cells, which was present in all liver diseases tested, but particularly expanded in PSC. This population had a transcriptome and T cell receptor repertoire similar to circulating naive T cells but expressed a set of genes associated with tissue residency. Their periductal location supported the concept of tissue-resident naive-like T cells in livers of patients with PSC. Trajectory inference suggested that these cells had the developmental propensity to acquire a T helper 17 (TH17) polarization state. Functional and chromatin accessibility experiments revealed that circulating naive T cells in patients with PSC were predisposed to polarize towards TH17 cells. Conclusion We report the first atlas of intrahepatic T cells in PSC, which led to the identification of a previously unrecognized population of tissue-resident naive-like T cells in the inflamed human liver and to the finding that naive CD4+ T cells in PSC harbour the propensity to develop into TH17 cells. Lay summary The composition of intrahepatic immune cells in primary sclerosing cholangitis (PSC) and their contribution to disease pathogenesis is widely unknown. We analysed intrahepatic T cells and identified a previously uncharacterized population of liver-resident CD4+ T cells which are expanded in the livers of patients with PSC compared to healthy liver tissue and other liver diseases. These cells are likely to contribute to the pathogenesis of PSC and could be targeted in novel therapeutic approaches., Graphical abstract, Highlights • First single-cell atlas of intrahepatic T cell landscape in PSC. • Identification of tissue-resident naive-like CD4+ T cells in human liver which are expanded in livers of patients with PSC. • Trajectory inference suggested a developmental propensity of these cells to acquire a TH17 polarization state. • Functional experiments, using circulating naive CD4+ T cells, support the inferred propensity to acquire a TH17 polarization state. • Chromatin accessibility studies revealed imprinting of naive CD4+ T cells towards effector function in PSC.

Histopathologic diagnosis relies on simultaneous integration of information from a broad range of scales, ranging from nuclear aberrations ($\approx \mathcal{O}(0.1{\mu m})$) through cellular structures ($\approx \mathcal{O}(10{\mu m})$) to the global tissue architecture ($\gtrapprox \mathcal{O}(1{mm})$). To explicitly mimic how human pathologists combine multi-scale information, we introduce a family of multi-encoder FCNs with deep fusion. We present a simple block for merging model paths with differing spatial scales in a spatial relationship-preserving fashion, which can readily be included in standard encoder-decoder networks. Additionally, a context classification gate block is proposed as an alternative for the incorporation of global context. Our experiments were performed on three publicly available whole-slide images of recent challenges (PAIP 2019, BACH 2020, CAMELYON 2016). The multi-scale architectures consistently outperformed the baseline single-scale U-Nets by a large margin. They benefit from local as well as global context and particularly a combination of both. If feature maps from different scales are fused, doing so in a manner preserving spatial relationships was found to be beneficial. Deep guidance by a context classification loss appeared to improve model training at low computational costs. All multi-scale models had a reduced GPU memory footprint compared to ensembles of individual U-Nets trained on different image scales. Additional path fusions were shown to be possible at low computational cost, opening up possibilities for further, systematic and task-specific architecture optimization. The findings demonstrate the potential of the presented family of human-inspired, end-to-end trainable, multi-scale multi-encoder FCNs to improve deep histopathologic diagnosis by extensive integration of largely different spatial scales., Comment: Accepted for Medical Image Analysis

HSD3B2 plays a crucial role in steroid hormone biosynthesis and is thus of particular interest in hormone dependent tumors such as prostate cancer. To clarify the clinical relevance of HSD3B2 expression in prostate cancer, we analyzed HSD3B2 protein expression by immunohistochemistry on our preexisting tissue microarray with 12.247 annotated cancers. Compared with normal tissue cytoplasmic HSD3B2 staining was stronger in prostate cancers. In 9371 interpretable cancers, HSD3B2 expression was found in 95.5% of cancers and was considered weak in 29.9%, moderate in 40.7% and strong in 24.9%. HSD3B2 up regulation was linked to advanced pathological tumor stage (pT), high Gleason grade, elevated preoperative PSA levels (p 0.0001 each), lymph node metastasis (p = 0.0019), accelerated cell proliferation (p 0.0001), androgen receptor (AR) expression (p 0.0001), and early biochemical recurrence (p 0.0001). HSD3B2 up regulation was only marginally more frequent in ERG positive (98%) than in ERG negative cancers (94%; p 0.0001) and was strongly linked to deletions of 5q and 6q (p 0.0001 each). Multivariate analyses showed that the prognostic impact of HSD3B2 expression was independent of established preoperative, but not of postoperative prognostic parameters. In summary, the results of our study demonstrate that HSD3B2 is strongly up regulated in a fraction of prostate cancers that are characterized by increased AR signaling, adverse tumor phenotype and early biochemical recurrence.

The controlled attenuation parameter (CAP) measured by transient elastography allows for the noninvasive assessment of hepatic steatosis. However, discrepant results between CAP values and histological evaluation have been reported in particular with high CAP values. We therefore investigated the diagnostic validity of high CAP measurements.Forty patients with liver disease and CAP measurements 300 dB/m that underwent ultrasound-guided or minilaparoscopic liver biopsy were retrospectively enrolled. CAP values were compared with the respective histological and macroscopic evaluation and correlated with clinical parameters.CAP values 300 dB/m had an 87.5 % specificity for detection of hepatic steatosis but failed to discriminate between steatosis grade S1 - S3. Discordant results, defined as a discrepancy of at least 2 steatosis grades between transient elastography and liver biopsy, were observed in 40 % of cases. The interquartile range (IQR) of CAP was confirmed as a predictor of discrepant findings. Macroscopic evaluation as part of minilaparoscopy detected hepatic steatosis in 74 % of patients with histological grade S2 - S3 in contrast to only 10 % classified as histological grade S0 - S1.High CAP measurements need to be interpreted with care and with regard to clinical parameters, in particular when high IQR values are registered.ZIEL: Der durch transiente Elastografie gemessene Controlled Attenuation Parameter (CAP) ermöglicht die nicht-invasive Beurteilung der Steatosis hepatis. Insbesondere im Falle hoher CAP-Werte wurden jedoch abweichende Ergebnisse zwischen CAP-Werten und histologischer Untersuchung berichtet. Ziel dieser Studie ist es, die diagnostische Gültigkeit hoher CAP-Messungen zu untersuchen.40 Patienten mit Lebererkrankung und CAP-Messungen 300 dB/m sowie sonografisch gesteuerter oder minilaparoskopischer Leberbiopsie wurden retrospektiv eingeschlossen. Die CAP-Werte wurden mit den jeweiligen histologischen und makroskopischen Beurteilungen verglichen sowie mit klinischen Parametern korreliert.CAP-Werte 300 dB/m wiesen eine Spezifität von 87,5 % für den Nachweis einer Steatosis hepatis auf, konnten jedoch zwischen den Steatosegraden S1 – S3 nicht unterscheiden. Diskordante Ergebnisse, definiert als eine Diskrepanz von mindestens zwei Steatosegraden zwischen transienter Elastografie und Leberbiopsie, wurden in 40 % der Fälle beobachtet. Der Interquartilsabstand der CAP-Messung wurde als Prädiktor für diskrepante Befunde bestätigt. Die makroskopische Beurteilung im Rahmen einer Minilaparoskopie lieferte in 74 % der Patienten mit histologischer Steatosis S2 – S3 vs. 10 % der Patienten mit histologischer Steatosis S0 – S1 Hinweise auf eine vorliegende Steatosis hepatis.Hohe CAP-Messungen müssen insbesondere im Falle ebenfalls erhöhter IQR-Werte sorgfältig und in Zusammenschau mit den klinischen Parametern bewertet werden.

Rationale: Ventricular arrhythmias remain the leading cause of death in patients suffering myocardial ischemia. Myeloperoxidase, a heme enzyme released by polymorphonuclear neutrophils, accumulates within ischemic myocardium and has been linked to adverse left ventricular remodeling. Objective: To reveal the role of myeloperoxidase for the development of ventricular arrhythmias. Methods and Results: In different murine models of myocardial ischemia, myeloperoxidase deficiency profoundly decreased vulnerability for ventricular tachycardia on programmed right ventricular and burst stimulation and spontaneously as assessed by ECG telemetry after isoproterenol injection. Experiments using CD11b/CD18 integrin–deficient (CD11b −/− ) mice and intravenous myeloperoxidase infusion revealed that neutrophil infiltration is a prerequisite for myocardial myeloperoxidase accumulation. Ventricles from myeloperoxidase-deficient (Mpo −/− ) mice showed less pronounced slowing and decreased heterogeneity of electric conduction in the peri-infarct zone than wild-type mice. Expression of the redox-sensitive gap junctional protein Cx43 (Connexin 43) was reduced in the peri-infarct area of wild-type compared with Mpo −/− mice. In isolated wild-type cardiomyocytes, Cx43 protein content decreased on myeloperoxidase/H 2 O 2 incubation. Mapping of induced pluripotent stem cell–derived cardiomyocyte networks and in vivo investigations linked Cx43 breakdown to myeloperoxidase-dependent activation of matrix metalloproteinase 7. Moreover, Mpo −/− mice showed decreased ventricular postischemic fibrosis reflecting reduced accumulation of myofibroblasts. Ex vivo, myeloperoxidase was demonstrated to induce fibroblast-to-myofibroblast transdifferentiation by activation of p38 mitogen-activated protein kinases resulting in upregulated collagen generation. In support of our experimental findings, baseline myeloperoxidase plasma levels were independently associated with a history of ventricular arrhythmias, sudden cardiac death, or implantable cardioverter–defibrillator implantation in a cohort of 2622 stable patients with an ejection fraction >35% undergoing elective diagnostic cardiac evaluation. Conclusions: Myeloperoxidase emerges as a crucial mediator of postischemic myocardial remodeling and may evolve as a novel pharmacological target for secondary disease prevention after myocardial ischemia.