Leucocyte Esterase Reagent Strips for the Diagnosis of Spontaneous Bacterial Peritonitis: A Systematic Review

Abstract

Purpose: Spontaneous bacterial peritonitis (SBP) is a potentially life-threatening complication of decompensated liver disease. Ascitic fluid polymorphonuclear (PMN) count ≥ 250/ mm3 objectively confirms SBP. The existing “gold standard” for the evaluation of ascitic PMN count (manual count) is however laborious and time-consuming. Recently leukocyte esterase reagent (LER) strips (common urine dipsticks) have been successfully used for the diagnosis of infection in various body fluids. The test is based on the esterase activity of PMN. Hence, they provide a cheap, easily accessible and rapid method for the diagnosis of PMN presence in the ascitic fluid. Aims: We aimed to systematically review the existing evidence on the diagnostic value of LER strips in SBP. Methods: Comprehensive literature search of Medline up to April 2007 for human clinical trials comparing LER strips with manual count of PMN in ascitic fluid. MeSH terms used included [“ascites” OR “ascitic fluid” OR “peritonitis”] AND [“reagent strips” OR “Leuc(k)ocyte esterase strips”]. Abstracts reviewed independently by two authors and full papers of relevent studies were obtained. Results: We identified 16 relevant studies (thirteen in English and from 1 in French, Chinese and Korean) comprising 2519 patients. Thirty of them were Child-Pugh (CP) stage A, 849 CP-stage B, and 1267 CP-stage C. A total of 4730 paracenteses was performed. A total of 521 SBP was diagnosed. Various dipsticks were evaluated; Nephur (2 times), Multistix10SG (7 times), Aution (1 time), UriScan (2 times), Multistix8SG (5 times) and Combur tests (5 times). Compared to manual count of PMN (“gold standard”), LER strips were found to have sensitivity ranging from 45.3% to 100%; specificity ranging from 84.75% to 100%; positive predictive value ranging from 42% to 100%; negative predictive value ranging from 87% to 100%. Conclusion: Use of LER strips in ascitic fluid is a useful method for the early diagnosis of SBP.