Analysis of Less Common Body Fluids: Part 3 -⁠ Pericardial fluid (pathophysiology, reference intervals for basic tests, clinical conditions)

Overview

Pericardial fluid, located between the visceral and parietal layers of the pericardium, has a specific composition that differs from other serous cavities and plays a key role in the diagnosis and pathophysiology of cardiac diseases. The historical division of effusions into exudates and transudates using Light's criteria is inadequate for pericardial fluid, as even physiological samples are classified as exudates according to these criteria. More recent studies define reference intervals for the main biochemical and morphological parameters, confirming higher levels of cellular elements, proteins, LDH, and other biomarkers. Pathophysiologically, the development of pericardial effusions may be based on increased capillary permeability, mesothelial activation, or lymphatic drainage disorders. The etiology includes infectious and non-infectious causes, most commonly malignancies, infections, autoimmune and iatrogenic conditions. Significant attention is paid to new biomarkers or biomarkers currently used in new applications. The aim of this communication is to summarize current knowledge about the composition and function of pericardial fluid, to highlight the limitations of traditional classifications, and to emphasize the diagnostic potential of new molecules with clinical and prognostic significance.

Keywords:

pericarditis – pericard – pericardial fluid – effusion