Post-BCG vaccination check based on serum IgG to culture filtrate antigens.

Since there are no reliable methods to demonstrate the effect of BCG vaccination in children, culture filtrates of BCG were evaluated for their specificity and sensitivity. BCG culture filtrate (BCG-CF), BCG sonicate and tuberculin were used as antigens and tested against serum, for the presence of IgG class of antibodies by ELISA and Western blot. Methodology: Children in the age-group of 1 to 10 years, were categorized as: (a) normal, and vaccinated, n=35; (b) normal, without a scar and with no evident history of vaccination, n=15; and (c) children with tuberculosis (meningitis, miliary and lymphadenitis) n=15. Results: The mean values of optical density (OD) in group (a), 4.0+0.08, were significantly high (P<0.001) to BCG-CF, compared to that of groups (b) (1.0+0.02) and (c) (1.4+0.03). The Western blot results revealed that a greater number of children (71%) in the vaccinated group reacted to low molecular weight proteins (10-30kDa) compared to other groups (unvaccinated: 17% and TB: 20%). The overall specificity, sensitivity, positive predictive value and negative predictive value of BCG-CF were higher in the vaccinated group. Conclusions: The results of the study suggest that the secreted antigens of BCG induce antibody formation, which are specific and are directed mostly towards the low molecular weight proteins. The presence of these antibodies could probably be exploited in an assay to distinguish children immunized by BCG from the unvaccinated and those having tuberculosis.

Serum Adenosine deaminase activity and C-reactive protein levels in unstable angina.

In unstable angina (USA) patients, immunological responses contributing to inflammation play a vital role in plaque rupture and thrombosis causing stroke. In the present study an attempt is made to estimate the levels of adenosine deaminase activity, an immunoenzyme marker and C-reactive protein, a marker of inflammation in USA patients. 45 patients presenting USA and 50 age and sex matched healthy controls were included in the study. Serum ADA activity was measured spectrophotometrically at 630nm and serum C-reactive protein was detected using Avitex CRP kit, which is a rapid latex agglutination test. The Mean ADA levels were 41.15 ± 11.04 in patients and 20.71±5.63 in controls and 66.6% of patients and none of the controls were positive to CRP. The present study observed the importance of ADA as a serum marker in addition to CRP for assessing the immune response in USA patients.