title: Establishment of Elevated Serum Levels of IL-10, IL-8 and TNF-β as Potential Peripheral Blood Biomarkers in Tubercular Lymphadenitis: A Prospective Observational Cohort Study.
abstract: BACKGROUND
  Tubercular lymphadenitis (TL) is the most common form of extra-pulmonary tuberculosis (TB) consisting about 15-20% of all TB cases. The currently available diagnostic modalities for (TL), are invasive and involve a high index of suspicion, having limited accuracy. We hypothesized that TL would have a distinct cytokine signature that would distinguish it from pulmonary TB (PTB), peripheral tubercular lymphadenopathy (LNTB), healthy controls (HC), other lymphadenopathies (LAP) and cancerous LAP. To assess this twelve cytokines (Tumor Necrosis Factor (TNF)-α, Interferon (IFN) -γ, Interleukin (IL)-2, IL-12, IL-18, IL-1β, IL-10, IL-6, IL-4, IL-1Receptor antagonist (IL-1Ra), IL-8 and TNF-β, which have a role in pathogenesis of tuberculosis, were tested as potential peripheral blood biomarkers to aid the diagnosis of TL when routine investigations prove to be of limited value.
  
  
  RESULTS
  A prospective observational cohort study carried out during 2010-2013. This was a multi-center study with three participating hospitals in Delhi, India where through random sampling cohorts were established. The subjects were above 15 years of age, HIV-negative with no predisposing ailments to TB (n = 338). The discovery cohort (n = 218) had LNTB (n = 50), PTB (n = 84) and HC (n = 84). The independent validation cohort (n = 120) composed of patients with cancerous LAP (n = 35), other LAP (n = 20) as well as with independent PTB (n = 30), LNTB (n = 15) and HC (n = 20). Eight out of twelve cytokines achieved statistical relevance upon evaluation by pairwise and ROC analysis. Further, variable selection using random forest backward elimination revealed six serum biosignatures including IL-12, IL-4, IL-6, IL-10, IL-8 and TNF-β as optimal for classifying the LNTB status of an individual. For the sake of clinical applicability we further selected a three analyte panel (IL-8, IL-10 and TNF-β) which was subjected to multinomial modeling in the independent validation cohort which was randomised into training and test cohorts, achieving an overwhelming 95.9% overall classifying accuracy for correctly classifying LNTB cases with a minimal (7%) misclassification error rate in the test cohort.
  
  
  CONCLUSIONS
  In our study, a three analyte serum biosignatures and probability equations were established which can guide the physician in their clinical decision making and step wise management of LNTB patients. This set of biomarkers has the potential to be a valuable adjunct to the diagnosis of TL in cases where AFB positivity and granulomatous findings elude the clinician.
authors.affiliation: Department of Microbiology, Vallabhbhai Patel Chest institute, University of Delhi, New Delhi, India.
authors.lastname: Abhimanyu
authors.affiliation: Department of Microbiology, Vallabhbhai Patel Chest institute, University of Delhi, New Delhi, India.
authors.forename: Mridula
authors.initials: M
authors.lastname: Bose
authors.affiliation: Department of Microbiology, Vallabhbhai Patel Chest institute, University of Delhi, New Delhi, India.
authors.forename: Mandira
authors.initials: M
authors.lastname: Varma-Basil
authors.affiliation: Department of Microbiology, Vallabhbhai Patel Chest institute, University of Delhi, New Delhi, India.
authors.forename: Ashima
authors.initials: A
authors.lastname: Jain
authors.affiliation: CSIR-Institute of Genomics and integrative Biology, New Delhi, India.
authors.forename: Tavpritesh
authors.initials: T
authors.lastname: Sethi
authors.affiliation: CSIR-Institute of Genomics and integrative Biology, New Delhi, India.
authors.forename: Pradeep Kumar
authors.initials: PK
authors.lastname: Tiwari
authors.affiliation: CSIR-Institute of Genomics and integrative Biology, New Delhi, India.
authors.forename: Anurag
authors.initials: A
authors.lastname: Agrawal
authors.affiliation: RajanBabu Institute of Pulmonary Medicine and Tuberculosis, Kingsway Camp, New Delhi, India.
authors.forename: Jayant Nagesh
authors.initials: JN
authors.lastname: Banavaliker
authors.affiliation: Department of Radiotherapy, Vardhman Mahavir Medical College and Safdarjung Hospital, Ansari Nagar west, New Delhi, India.
authors.forename: Kumar Tapas
authors.initials: KT
authors.lastname: Bhowmick
mesh_terms: D000328:Adult; D015415:Biomarkers; D016022:Case-Control Studies; D016207:Cytokines / Q000097:blood*; D005260:Female; D006801:Humans; D016753:Interleukin-10 / Q000097:blood; D016209:Interleukin-8 / Q000097:blood; D008233:Lymphotoxin-alpha / Q000097:blood; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D011446:Prospective Studies; D015203:Reproducibility of Results; D014388:Tuberculosis, Lymph Node / Q000097:blood* / Q000175:diagnosis; D055815:Young Adult
chemical_list: D015415:Biomarkers; D016207:Cytokines; D016209:Interleukin-8; D008233:Lymphotoxin-alpha; D016753:Interleukin-10