Accuracy of Uric Acid and Cholesterol Levels Examination in Distinguishing Pleural Effusion Fluid Exudates and Transudates


  • Yusup Subagio Sutanto Department of Pulmonology and Respiratory Medicine, Faculty of Medicine, Universitas Sebelas Maret, Dr. Moewardi Hospital, Surakarta


Background: Light's criteria was reported 25% of misclassification transudates as exu­dates. This study aimed to analyse the accuracy of examining uric acid levels and pleural fluid uric acid levels, and pleural fluid cholesterol and cholesterol ratios to distinguish the exudates and transudates in pleural effusions.

Subjects and Method: This was a cross-sectional study de­sign conducted at Dr. Moe­wardi Hospital, Surakarta, Central Java, from July to August 2019. The study subjects were 30 pleural effusion patients treated in the pul­monology ward. The dependent variables were pleural fluid exudates and transudates. The indepen­dent variables were (1) Uric acid levels in pleu­ral fluid; (2) The ratio of uric acid levels be­tween pleural fluid and serum; (3) Pleural fluid cholesterol levels; and (4) The ratio of cho­lesterol levels between pleural fluid and serum. The study instruments were Light's cri­teria and laboratory examination. The diag­nosis's accuracy was analysed using sensi­tivi­ty, specificity, and the area under the ROC (AUC) curve.

Results: Pleural fluid cholesterol showed sen­­sitivity and specificity of 86% and 83%, with a cut-off of 32.00 for transudate results. AUC value = 0.82 with p = 0.012. Serum cholesterol showed sensitivity and specificity of 71% and 61%, with a cut-off of 175.50 for transudate re­sults. AUC value = 0.67 with p = 0.194. Pleu­ral fluid uric acid levels showed a sensitivity and specificity of 86% and 87%, with a cut-off of 7.25 for transudate results. AUC value = 0.83 with p = 0.009. Examination of serum uric acid levels showed a sensitivity and specificity of 86% and 70%, with a cut-off of 7.10 for trans­udate results. AUC value = 0.65 with p = 0.249.

Conclusion: Examination of uric acid and pleural fluid cholesterol levels can be used in routine pleural effusion examinations to distin­guish exudates and transudates.

Keywords: accuracy, uric acid, exudates, cho­les­te­rol, transudates

Correspondence: Yusup Subagio Sutanto. Department of Pul­mo­no­logy and Respiratory Medicine, Faculty of Medicine Universitas Sebelas Maret, Dr. Moe­wardi Hospital, Surakarta. Jl. Kolonel Sutarto 132, Jebres, Surakarta 57126, Central Java. Email: dr_yusupsubagio­ Mobile: +62811284165.

Indonesian Journal of Medicine (2021), 06(02): 159-167



Antony VB (2003). Immunological mechanisms in pleural disease. Eur Respir J. 21(3): 539–544. doi: 10.11-83/-09031936.-03.00403902.

Bansal A, Tandon S, Kharb S (2010). Diag-nostic value of uric acid in pleural effu sion. Zhongguo Fei Ai Za Zhi. 13(4): 349–351.

Mason RJ, Broaddus VC, Martin TR, King TE, Schraufnagel DE, Murray JE, Nadel JA (2010). Murray and Nadel's Textbook of Respiratory Medicine. Fifth Edition. Philadelphia: Elsevier Saunders, 1719-63.

Bouros D (2009). Pleural Disease. Second Edition. New York: Marcel Dekker. 237-52.

Grippi MA, Elias JA, Fishman JA, Kotloff RM, Pack AI, Senior RM (2015). Fish-man's Pulmonary Diseases and Dis-orders. Fifth Edition. New York: Mc-Graw-Hill Education, 1168–1187.

Jain A, Jain R, Petkar SB, Gupta SK, Khare N, Dutta J (2015). A study of uric acid - a new biochemical marker for the differentiation between exudates and transudates in a pleural effusion cas-es. National Journal of Community Medicine. 5(2): 204–208.

Light RW (2013). Pleural Diseases. Sixth Edition. Philadelphia: Lippincott Williams & Wilkins, 128–39.

Maskell NA, Butland RJA (2003). BTS guidelines for the investigation of a unilateral pleural effusion in adults. Thorax. 58: 8–17.

Oliveira EP, Burini RC (2012). High plasma uric acid concentration: causes and con sequences. BioMed Central. 4(12): 1–7. doi: 10.1186/1758-5996-4-12.

Peng M-J, Wang N-S (2004). Anatomy of the pleura. In: Bouros D.(ed.). Pleural Disease. New York: Marcel Dekker, Inc, pp.23-40.

Porcel JM (2013). Identifying transudates misclassified by Light's criteria. Curr Opin Pulm Med. 19(4): 362–367. doi: 10.1097/MCP.0b013e32836 02 2-d c.

Putra I, Yunus F (2013). Pleural Anatomy and Physiology. 40(6): 407–412.

Richard WL (2013). The Light criteria: the beginning and why they are useful 40 years later. Clin Chest Med. 34(1): 21–26. doi: 10.1016/j.ccm.2012.11.006.

Yalcin NG, Choong CKC, Eizenberg N (2013). Anatomy and pathophysiology of the pleura and pleural space. Thorac Surg Clin. 23(1): 1–10. doi: 10.-1016/j.thorsurg.2012.10.008.