Comparative Study of Different Test Systems For Measuring Cytokine Production among Tuberculous and Healthy Persons.
1Morsi MG, 2Atta HY and 3Rabie AK.
1Microbiology, 2Community Medicine, 3Chest Diseases Departments, Faculty of Medicine, Alexandria University, Alexandria, Egypt.
The aim of the study was to establish a test system which permits the screening of large numbers of cell samples from patients to asses their immunological status. The studied subjects were 3 healthy groups (n = 50) of different ages; GPI (n=20) aged 20-50 years, GPII (n=20) aged 60-74 years and, GPIII (n=10) aged 75-85 years, as well as 2 groups of tuberculous patients; GP IV smear positive TB patients (n = 20) resisting four antituberculous drugs for more than 6 months, and GPV (n=20) smear negative TB patients. Comparing mitogen induced whole blood culture, plasma and serum test systems for measuring IL-2 production with isolated PBMC culture(gold standard), a good agreement was found (Kappa=0.84) of whole blood culture system with PBMC cultures provided that the cell numbers were adjusted in both systems. The whole blood culture system was also found to be of high sensitivity (100%) and specificity (80.6%). On the other hand, the plasma and serum systems were not suitable for cytokine assessment as non of them could detect the interleukin studied. Cytokines (IL-2, TNFa , IFNg ) levels in the blood were significantly higher than those of the PBMC cultures. Smear positive and smear negative TB patients and the healthy controls had significantly different levels of cytokines. High levels of IL-2 were detected among smear negative TB patients, whereas TNFa high values were demonstrated among smear positive TB patients. The controls revealed the highest IFNg values. IL-2 and TNFa values were inversely proportional. From these results, we conclude that despite the complexity of the cellular events taking place in these cultures, whole blood tests do indeed reflect the performance of T- lymphocytes and monocytes among tuberculous and healthy subjects.