Reference Values of Cells, Total Proteins, Albumin, LDH, Cholesterol and Glucose in Periacardial Fluid

Background: Reference intervals (RI) of cells, total proteins, albumin, LDH, cholesterol and glucose in pericardial fluid are not well defined. Methods: One-hundred and twenty consecutive pericardial fluid samples obtained from subjects undergoing cardiac surgery were analysed for cells (Sysmex XN and optical microscopy) and analytes, according to the current required standards. Findings: The obtained median values (M) and reference intervals (RI) were: total protein M 2.8, RI 1.7-4.6 g/dL; total cholesterol M 27, RI 12-69 mg/dL; LDH M 357, RI 141-2613 U/L; albumin M 1.92, 1.19-3.06 g/dL. The median pericardial fluid/serum ratio was 0.5 for total protein and 1.1 for LDH.The median value and RI for total nucleated cells and white blood cells by optical microscopy were: M 1977, RI 278-5608 x106 /L; M 503, RI 35-2210 x106 /L. A very high number of mesothelial cells was observed. Interpretation: Normal pericardial fluid is rich of total nucleated cells, total protein, albumin, LDH, with values that, particularly for LDH, would be consistent with inflammatory exudates in other biological fluid. Physician should stop considering as inflammatory exudate a pericardial fluid whose total cells, total protein, albumin, and LDH are within the above-mentioned reference values. Funding Statement: This study has been funded by the National Italian Health Service Declaration of Interests: Antonio Brucato: institutional unrestricted research grants by ACARPIA and SOBI. All other authors: no conflict of interest to disclose. Ethics Approval Statement: The study was approved by the institutional ethics committee, and it is in line with Helsinki Declaration.