The exact answer to why ADA (Adenosine Deaminase) levels are high in Tuberculosis (TB) is because of the stimulation of T cells by mycobacterial antigens.
ADA serves as a potentially useful marker for TB because its levels rise significantly in response to the presence of the Mycobacterium tuberculosis bacteria.
Understanding ADA and TB
ADA is an enzyme involved in purine metabolism, particularly important for the development and function of lymphocytes, which are a type of white blood cell. In the context of TB, the immune system's response to the infection involves a significant activation of T cells.
As stated in the reference:
Furthermore, ADA has been proposed to be a useful surrogate marker for TB because it can be detected in body fluids such as pleural, pericardial and peritoneal fluid. The levels of ADA increase in TB because of the stimulation of T cells by mycobacterial antigens.
This means that when the body encounters the antigens (specific molecules) from the TB bacteria, it triggers an immune response that heavily involves T cells. This stimulation leads to an increase in ADA production and activity, primarily by these activated immune cells.
ADA as a Diagnostic Marker
Due to this rise in concentration, ADA can be measured in various body fluids where TB infection might be present. Elevated ADA levels in these fluids can strongly suggest a diagnosis of tuberculosis in that specific location.
Common body fluids where elevated ADA is assessed for TB include:
- Pleural fluid (around the lungs)
- Pericardial fluid (around the heart)
- Peritoneal fluid (in the abdomen)
In summary, the high levels of ADA seen in TB are a direct result of the body's immune system, specifically its T cells, being stimulated to fight the mycobacterial infection.
