The laboratory investigation of pleural fluids: An update based on the available evidence.

Selecting appropriate laboratory tests based on available evidence is central to improve clinical effectiveness and impacting on patient outcome. Although long studied, there is no mutual agreement upon pleural fluid (PF) management in the laboratory context. Given the experienced confusion about the real contribution of laboratory investigations to guide clinical interpretation, in this update, we tried to identify useful tests for the PF analysis, aiming to unravel critical points and to define a common line in requesting modalities and practical management.

Sources and clinical significance of aspartate aminotransferase increases in COVID-19.

Background: Aspartate aminotransferase (AST) is often increased in COVID-19 and, in some studies, AST abnormalities were associated with mortality risk.

Methods: 2054 hospitalized COVID-19 patients were studied. To identify sources of AST release, correlations between AST peak values and other biomarkers of tissue damage, i.