Assessment of Pleural fluid cholesterol & Protein in analysing Exudates & Transudates

Abstract

Introduction : Pleural effusion is defined as an abnormal and excessive collection of fluid in the pleural space. The
most common cause in the West and India are infections followed by malignancy. In India, tubercular effusion is the
most common cause followed by malignant effusion and a very few due to parapneumonic effusion. Aims and
Objectives- To study the role of pleural fluid cholesterol in differentiating transudative and exudative pleural
effusion and comparison of pleural fluid cholesterol to Light’s criteria. Methods: This prospective study was
carried out in hundred randomly selected adult patients of both sexes suffering from pleural effusion, where
thoracocentesis yield a sufficient good quantity of pleural fluid for examination, were included. The patients were
divided into three groups clinically according to expected nature of the fluid on aetiological grounds. Results: The
aetiological classification of the 100 effusions is shown in table 1. According to the causal disease, 22 pleural fluid
samples were labelled as transudates and 78 were labelled as exudates. The commonest type of effusion was found
to be Tuberculous followed by Malignancy, Para-pneumonic, Congestive heart failure, Chronic liver disease.
Results show that an increased concentration of cholesterol greater than 60 mg/dL and/or total protein levels greater
than 3 g/dL in pleural fluid constitute useful measurements for separating exudates from transudates.Conclusion:
Combined pleural fluid cholesterol and total protein are simple, cost effective, and useful parameters for
differentiation of transudates from exudates. Simultaneous measurement of total protein and cholesterol in pleural
fluid permits the identification of exudates through the elevation of either one or both of these indicators, with an
accuracy superior to the best that has been reported with the criteria of Light et al. The proposed combination has
the advantages that a simultaneous blood sample is not required and that chemical tests are reduced from four to
two, thereby, lowering the cost of the diagnostic procedure.