Open AccessThe Clinical Utility of the Neutrophil-to-Lymphocyte Ratio as a Discriminatory Test among Bacterial, Mycobacterium Tuberculosis, and Nontuberculous Mycobacterium Peritoneal Dialysis–Related Peritonitis
Author(s) -
Winston WingShing Fung,
Kai Ming Chow,
Jack KitChung Ng,
George C.-Y. Chan,
Philip KamTao Li,
CheukChun Szeto
Publication year - 2022
Publication title -
kidney360
Language(s) - English
Resource type - Journals
ISSN - 2641-7650
DOI - 10.34067/kid.0000842022
Subject(s) - medicine , peritonitis , gastroenterology , mycobacterium tuberculosis , peritoneal dialysis , nontuberculous mycobacteria , tuberculosis , immunology , surgery , pathology , mycobacterium
Background. Distinguishing mycobacterium tuberculosis (TB) and non-tuberculous mycobacterium (NTM) from bacterial peritoneal dialysis (PD) related peritonitis (peritonitis) is often very challenging and can lead to significant delay in diagnosis and treatment. The neutrophil-to-lymphocyte ratio (NLR) is a readily calculable ratio that has been shown to be useful in differentiating pulmonary TB from bacterial pneumonia. We are the first group to demonstrate the predictive efficacy of peritoneal dialysate (PDE) NLR in distinguishing TB/NTM peritonitis from bacterial causes in PD population. Method. We retrospectively reviewed the clinical and laboratory characteristics of all patients with TB/NTM peritonitis, methicillin-sensitive staphylococcus aureus (MSSA) peritonitis and culture-negative peritonitis in our tertiary centre between July 2000 and July 2020. The diagnostic ability of the blood and PDE NLR for differential diagnosis was evaluated. Result. 258 episodes; 38 episodes and 27 episodes were caused by MSSA, TB and NTM species respectively. 364 episodes were culture-negative. The PDE NLR level taken at presentation were lowest in the TB peritonitis, followed by the NTM, culture-negative and MSSA group (9.44 ± 13.01, 16.99 ± 23.96, 36.63 ± 32.33, 48.51 ± 36.01; p <0.001, respectively). The area under the Receiver-operating characteristic curve for the NLR taken at presentation was 0.83 (95% confidence interval, 0.77-0.89; p<0.001). A PDE NLR <15 was an optimal cut-off value with the sensitivity, specificity, positive predictive value and negative predictive value being 81.0%, 70.2%, 96.6% and 21.8% respectively. Conclusion. The PDE NLR obtained at presentation is a useful and easily accessible marker to discriminate TB/NTM peritonitis from bacterial peritonitis, especially in area with intermediate TB/NTM burden. The NLR may enable early prompting of TB/NTM peritonitis, allowing specific investigation and treatment being instigated earlier.