No abstract

Stromal cells (SCs) establish the compartmentalization of lymphoid tissues critical to the immune response. However, the full diversity of lymph node (LN) SCs remains undefined. Using droplet-based single-cell RNA sequencing, we identified nine peripheral LN non-endothelial SC clusters. Included are the established subsets, Ccl19 T-zone reticular cells (TRCs), marginal reticular cells, follicular dendritic cells (FDCs), and perivascular cells. We also identified Ccl19 TRCs, likely including cholesterol-25-hydroxylase cells located at the T-zone perimeter, Cxcl9 TRCs in the T-zone and interfollicular region, CD34 SCs in the capsule and medullary vessel adventitia, indolethylamine N-methyltransferase SCs in the medullary cords, and Nr4a1 SCs in several niches. These data help define how transcriptionally distinct LN SCs support niche-restricted immune functions and provide evidence that many SCs are in an activated state.

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Background and Aims: COVID-19 is a dominant pulmonary disease, with multisystem involvement, depending upon co morbidities. Its pro le in patients with pre-existing chronic liver disease (CLD) is largely unknown. We studied the liver injury patterns of SARS-Cov-2 in CLD patients, with or without cirrhosis. Methods: Data was collected from 13 Asian countries on patients with CLD, known or newly diagnosed, with con rmed COVID-19. Result: Altogether, 228 patients [185 CLD without cirrhosis and 43 with cirrhosis] were enrolled, with comorbidities in nearly 80%. Metabolism associated fatty liver disease (113, 61%) and viral etiology (26, 60%) were common. In CLD without cirrhosis, diabetes [57.7% vs 39.7%, OR=2.1(1.1-3.7), p=0.01] and in cirrhotics, obesity, [64.3% vs. 17.2%, OR=8.1(1.9-38.8), p=0.002) predisposed more to liver injury than those without these. Forty three percent of CLD without cirrhosis presented as acute liver injury and 20% cirrhotics presented with either acute-on-chronic liver failure [5(11.6%)] or acute decompensation [4(9%)]. Liver related complications increased (p<0.05) with stage of liver disease; a Child-Turcotte Pugh score of 9 or more at presentation predicted high mortality [AUROC-0.94, HR=19.2(95CI 2.3-163.3), p<0.001, sensitivity 85.7% and speci city 94.4%). In decompensated cirrhotics, the liver injury was progressive in 57% patients, with 43% mortality. Rising bilirubin and AST/ALT ratio predicted mortality among cirrhosis. Conclusions: SARS-Cov-2 infection causes signi cant liver injury in CLD patients, decompensating one fth of cirrhosis, and worsening the clinical status of the already decompensated. The CLD patients with diabetes and obesity are more vulnerable and should be closely monitored.