Alterations of PSA, CA15.3, CA125, Cyfra21-1, CEA, CA19.9, AFP and Tag72 tumor markers in human blood serum due to long term exposure to high levels of natural background radiation in Ramsar, Iran

Ramsar [Mazandran province] is known for its extremely high levels of natural background radiation. Although no excess cancer rate is reported in these areas by epidemiological studies, the study of tumor markers in the inhabitants of these areas may shed some light on the impact of high levels of background radiation on cancer induction. The level of background gamma radiation as well as indoor radon was determined using RDS-110 and CR-39 dosimeters. Thirty five individuals from a high background radiation area [HBRA] and 53 individuals from a normal background radiation area [NBRA] were randomly selected to participate in the study. Commercial ELISA kits [sandwich type ELISA tests] were used to measure the serum levels of PSA, CA15.3, CA125, Cyfra21-1, CEA, CA19.9, AFP and Tag72 tumor markers. Among the eight biomarkers investigated, the means of PSA, CA15.3, CA125, CA19.9 and AFP concentrations between the HBRAs and NBRAs were not significantly different. However, Cyfra21, CEA and Tag72 in HBRA group revealed statistically significant increases compared to those of NBRA group [P<0.05]. Furthermore, a statistically significant correlation between the external gamma dose as well as indoor radon level and the concentration of CEA [P<0.001], Cyfra-21[P<0.001] and TAG 72 [P<0.001 and 0.01 respectively] biomarkers were observed. Chronic exposure to high background radiation induces significant alterations in Cyfra21, CEA and Tag72 levels. We believe that studies with other relevant tumor markers might overcome the limitations of epidemiological studies on cancer incidence in high background radiation areas

[Isolation and purification of Ag 85 complex from mycobacterium bovis [BCG] and assessment of its cell proliferation response in whole blood]

Introduction: Tuberculosis [TB] caused by Mycobacterium tuberculosis remains a major worldwide health problem. The only TB vaccine currently available is an attenuated strain of mycobacterium bovis termed Bacillus Calmette -Guerin [BCG]. The efficacy of BCG remains controversial. Mycobacterium secretory proteins are generally considered important antigens for protection against TB. A major protein component of mycobacterial culture filtrate is Antigen 85 complex which is a promising potential vaccine candidate

Material and Methods: Antigen 85 complex was purified from Mycobacterium bovis [BCG] culture filtrate by sequential chromatography on phenyl Sepharose 4B, DEAE-Sephacel and Superdex G75. Purification was confirmed by SDS-PAGE and immunoblotting with a specific monoclonal antibody. The in vitro ability of Ag 85 complex to stimulate cell proliferation was compared with that of Purified Protein Derivative [PPD] and the polyclonal T cell mitogen PHA in a whole blood assay in which the target cells were derived from 25 healthy PPD-positive and 25 healthy PPD-negative subjects

Results: Antigen 85 complex was found to have a molecular weight of 30-32 KDa by SDS-polyacrylamide gel electrophoresis and reacted strongly by immunoblotting with the monoclonal antibody specified against Ag 85. The responses to Ag 85 and PPD were significantly higher in cells of PPD- positive than in cells of PPD-negative donors. Eighty eight percent [22/25] of the PPD- positive cells responded to Ag 85 whereas only 16% [4/25] of the PPD-negative cells responded

Conclusion: The cell proliferation response to Ag 85 complex is significantly different between cells of skin-test positive and skin- test negative subjects and may suggest an immuno-protective role for Ag 85 complex against M. tuberculosis infection