title: Tuberculous lymphadenitis: skin delayed-type hypersensitivity reaction and cellular immune responses.
abstract: BACKGROUND
  Tuberculous lymphadenitis (TL) is the commonest form of extra-pulmonary tuberculosis in tropical countries.
  
  
  OBJECTIVE
  This study aimed to characterize in vivo and in vitro cellular immune responses to Mycobacterium PPD in TL patients as markers of disease and healing.
  
  
  METHODS
  Following informed consent, 36 TL patients, 40 patients with pulmonary tuberculosis (TB) and 20 apparently healthy individuals were enrolled when they met specific selection criteria. The tuberculin skin test (TST) and peripheral blood mono-nuclear cells (PBMCs) culture were conducted using PPD. The cytokines were measured using commercial kits.
  
  
  RESULTS
  The mean TST was 24.6 ±8.0 mm for TL patients. The TST was variable in pulmonary TB patients and healthy individuals. It was reactive in a third of pulmonary TB patients with a mean of 20 ±3.0 mm and reactive in half of the healthy individuals with a mean of 12.6 ±3.2 mm. Pre and post-treatment interferon gamma (IFN-g) mean levels were 498.6 ±905.8 pg/ml and 710.0 ±844.6 pg/ml respectively (p=0.0001) for TL patients, while IL-10 mean levels were 93.0 ±136.0 pg/ml and 32.4 ±31.7 pg/ml respectively (p= 0.0001). TST-reactive Pulmonary TB patients had significantly higher IFN-g (851 ±234.4 pg/ml) compared to TBLNT patients (p = 0.0001), while pulmonary TB patients had significantly lower IL-10 compared to TBLNT patients (p=0.0001). Apparently healthy individuals had significantly lower IFN-g and IL-10 levels compared to TBLNT and pulmonary TB patients (p=0.003).
  
  
  CONCLUSIONS
  Strong TST reactivity, high IFN-g and IL-10 levels are good surrogate markers of active TBLNT, while increasing IFN-g levels and decreasing IL-10 levels mark healing. Tuberculosis Skin Test reactivity although a good diagnostic marker does not disappear with treatment.
authors: Institute of Endemic Diseases, University of Khartoum, Sudan. eltahirk@iend.org
authors: E A
authors: EA
authors: Khalil
authors: A A
authors: AA
authors: Elnour
authors: A M
authors: AM
authors: Musa
authors: A A
authors: AA
authors: Elagib
authors: S H
authors: SH
authors: Hassab Elgawi
authors: W M
authors: WM
authors: Ismail
authors: K E
authors: KE
authors: Elzaki
mesh_terms: D000293:Adolescent; D000328:Adult; D044963:Biopsy, Fine-Needle; D016022:Case-Control Studies; D016207:Cytokines / Q000276:immunology*; D005260:Female; D006801:Humans; D006968:Hypersensitivity, Delayed / Q000276:immunology*; D007111:Immunity, Cellular / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D009169:Mycobacterium tuberculosis / Q000276:immunology* / Q000302:isolation & purification; D011446:Prospective Studies; D013397:Sudan; D014373:Tuberculin / Q000276:immunology; D014374:Tuberculin Test; D014388:Tuberculosis, Lymph Node / Q000276:immunology / Q000473:pathology*; D014397:Tuberculosis, Pulmonary / Q000097:blood / Q000276:immunology*; D055815:Young Adult
chemical_list: D016207:Cytokines; D014373:Tuberculin