Correlation of serum interleukin-2 receptor-alpha levels with clinical manifestations in pulmonary tuberculosis.
METHODS
The analysis of serum levels of soluble interleukin-2 receptor alpha (sIL-2R-alpha) is an indirect method of studying the in vivo state of immune activation, particularly in patients with pulmonary tuberculosis (PTB) where the disease is associated with cellular immune reactions.


OBJECTIVE
To quantitate the serum sIL-2R-alpha in patients and correlate with disease activity.


METHODS
The levels of sIL-2R-alpha were determined using ELISA in serum samples from untreated patients with PTB (n = 107), 30 of whom were later tested during treatment, household family contacts (n = 38), and healthy controls (n = 22).


RESULTS
Concentrations of sIL-2R-alpha were significantly higher in PTB patients than in controls (2845 +/- 187 vs 1217 +/- 80 pg/mL, P < 0.0001), and were even more pronounced in the sputum positive (3200 +/- 148 pg/mL) and treatment failure (3335 +/- 196 pg/mL) groups of patients. However, in household family contacts, the sIL-2R-alpha levels were found to be similar to those of healthy controls. The sIL-2R-alpha levels correlated positively with disease activity as assessed by roentgenographic findings. In six of the 16 responder patients, the sIL-2R-alpha levels fell from 3228 +/- 144 pg/mL to 1497 +/- 131 pg/mL (P < 0.0001) after 3 months of successful treatment with anti-tuberculosis drugs. However, no significant change was observed in the treatment failure patients even after one year of chemotherapy with second-line drugs.


CONCLUSIONS
These studies indicate that determination of serum concentrations of sIL-2R-alpha is a sensitive and specific method for monitoring disease activity in terms of T cell activation in pulmonary tuberculosis.
Rajalingam
R
R
Department of Histocompatibility and Immunogenetics, Lala Ram Sarup Institute of Tuberculosis and Allied Diseases, Mehrauli, New Delhi, India.
Mehra
N K
NK
Pande
J N
JN
Jain
R C
RC
Singla
R
R
D000328:Adult; D000995:Antitubercular Agents / Q000627:therapeutic use; D004797:Enzyme-Linked Immunosorbent Assay; D005192:Family Health; D005260:Female; D006801:Humans; D008297:Male; D009169:Mycobacterium tuberculosis / Q000302:isolation & purification; D015375:Receptors, Interleukin-2 / Q000032:analysis*; D013183:Sputum / Q000382:microbiology; D014397:Tuberculosis, Pulmonary / Q000097:blood* / Q000188:drug therapy / Q000382:microbiology
D000995:Antitubercular Agents; D015375:Receptors, Interleukin-2