Histopathological features of multiorgan percutaneous tissue core biopsy in patients with COVID-19.

AIMS: The global outbreak of COVID-19 has resulted in an increased mortality. However, whether severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can affect multiple organs is still unclear. In this study, postmortem percutaneous biopsies of multiple organs from deceased patients were performed to understand the histopathological changes caused by COVID-19. METHODS: Biopsy specimens of pulmonary, cardiac, hepatic and lymphoid tissues were obtained from three patients, who died due to COVID-19 pneumonia. H&E stain, Masson trichrome stain, immunohistochemistry stain and in-situ hybridisation were used. RESULTS: Pulmonary damages caused by SARS-CoV-2 infection was diffuse alveolar damage (DAD). In the early phase, the histological findings were mainly those of exudative features of DAD. The later phase was characterised by organisation of DAD combined with bacterial pneumonia. No serious damage was found in the bronchiolar epithelium and submucosal glands. The hepatic tissue revealed features of ischaemic necrosis, but findings suggestive of mild lobular hepatitis were also observed. The lymphoid tissue revealed features of non-specific acute lymphadenitis. The cardiac tissue revealed changes of underlying disease. SARS-CoV-2 RNAs were not detected in hepatocytes, cholangiocytes and lymphocytes of lymph nodes. CONCLUSIONS: COVID-19 predominantly involves the pulmonary tissue, causes DAD and aggravates the cardiovascular disease. However, other extrapulmonary tissues did not reveal any virus-specific findings, but were affected by multiple factors. The findings in this report caution the pathologists that they should not mistakenly attribute all the histological features to CoV infection. Moreover, the clinicians should pay attention to the potentially injurious and correctable causes.

Multicenter prospective study to validate a new transient elastography device for staging liver fibrosis in patients with chronic hepatitis B.

OBJECTIVES: To validate the operational and diagnostic performances of a new device for transient elastography (TE), FibroTouch, for liver fibrosis in patients with chronic hepatitis B (CHB). METHODS: In this prospective multicenter study, adult patients with CHB and valid liver pathological results were recruited to validate the operational and diagnostic performance of a TE device by FibroTouch for staging liver fibrosis. RESULTS: In total, 517 patients with histologically proven CHB were enrolled. All had achieved at least 10 successful liver stiffness measurements (LSM), resulting in a success rate of 99.1% and reliable evaluations of 95.2%. Altogether 412 patients were included to analyze the diagnostic performance of FibroTouch. The area under the receiver operating characteristic curve for the LSM was 0.846 (95% confidence interval [CI] 0.808-0.880) for fibrosis stage ≥ F1, 0.850 (95% CI 0.811-0.883) for ≥ F2, 0.908 (95% CI 0.876-0.934) for ≥ F3 and 0.874 (95% CI 0.836-0.903) for F4. The diagnostic accuracy of LSM was superior to that of gamma-glutamyl transpeptidase-to-platelet ratio (GPR), aminotransferase-to-platelet ratio index (APRI), or fibrosis index based on 4 factors (FIB-4) index in staging fibrosis F2-F4 (P = 0.007 to < 0.0001). Optimal LSM cut-off values for diagnosing fibrosis stage ≥ F1, ≥ F2, ≥ F3, and F4 were 5.5 kPa, 7.85 kPa, 10.0 kPa, and 12.7 kPa, respectively. CONCLUSION: FibroTouch has a high success rate and good reliability in staging liver fibrosis in patients with CHB.

Clonal characteristics of paired infiltrating and circulating B lymphocyte repertoire in patients with primary biliary cholangitis.

BACKGROUND: PBC is a prototypical autoimmune liver disease characterized by portal lymphoplasmacyte infiltration. ALD is a prototypical environment-driven disease, featured by mild lymphocyte infiltration. We hypothesize that B cells are more involved in the pathogenesis of PBC. By analysing the infiltrating B cell repertoire, we aimed to unveil greater oligoclonal expansion and active clonal exchange between liver and periphery in PBC than in ALD patients. METHODS: Using NGS of Ig H chain genes, we analysed the liver-infiltrating and paired peripheral B lymphocyte repertoire from nine PBC and four ALD patients. RESULTS: In the liver of PBC and ALD patients, (i) roughly 10% of the B lymphocytes were clonally related and highly expressed, and there were also lineages that underwent extensive clonal expansion; (ii) there was different use of IGHV/IGHJ segments between PBC and ALD, suggesting distinct Ag exposure backgrounds, but this did not lead to a significant difference in their clonal expansion level. Analysis of data sets from paired samples further revealed, (iii) direct clonal exchange and evolutionally related B cell clones between the infiltrating and peripheral repertoire; (iv) the seeding of the infiltrating clones to periphery, and peripheral ones to the liver, for further extensive evolution. CONCLUSIONS: The oligoclonally expanded nature of the infiltrating B cell repertoire implies B cell immunity is involved in the pathogenesis of both diseases. The observed clonal exchange might provide an approach to identify and monitor the infiltrating B cells through the periphery.

Pathological characteristics of liver biopsies in eight patients with hepatic epithelioid hemangioendothelioma.

We aim to investigate the pathological characteristics of liver biopsies and their implications for the prognosis of hepatic epithelioid hemangioendothelioma (HEHE). Clinical data of eight patients (5 male, 3 female) with HEHE were analyzed retrospectively. Expression of CD34, FVIII, AE1/AE3, Hepa-par1, GPC3, CK19 and the proliferation index marker Ki-67 were determined by immunohistochemical staining. The clinical pathological features and effects of treatment on prognosis were investigated. Among the eight patients, four did not exhibit significant symptoms, while four showed symptoms such as abdominal distension, aversion to greasy food and mild fever. Two patients had single liver lesions, while multiple lesions were observed in six cases, in which the tumor cells exhibited spindle, irregular or epithelioid morphology, with scattered, streaked and nested distribution. Individual luminal cells were also visible, containing red cells and accompanied by mucoid or fibrous stroma. All cases were CD34 positive, one case was FVIII factor negative, two cases were AE1/AE3 positive, Ki-67 staining exceeded 15% in two cases, and nuclear fission was visible in two cases. Patients with nuclear fission and Ki-67 > 15% died within 2 years after artery embolization, liver transplantation without relapse was observed in two cases and one case survived with the tumor. The other patients without cellular atypia, without nuclear fission and with Ki-67 < 10% did not relapse during the 2-5 years of follow-up. HEHE can be diagnosed according to hematoxylin and eosin morphology and immunohistochemical characteristics in biopsies before treatment allowing the selection of different treatment protocols based on pathological characteristics.