ADENOSINE DEAMINASE- ADA

Adenosine deaminase (ADA) is an enzyme widely distributed in mammalian tissues, particularly in T-Lymphocytes. ADA is an enzyme that catalyzes the deamination of adenosine, forming inosine in the process.
The chief physiological function of ADA is related to lymphocytic proliferation and differentiation. As a marker of cellular immunity, activity is found to be elevated in those diseases in which there is a cell-mediated immune response.
Increased levels of ADA are found in various forms of tuberculosis making it a marker for the same.
Though ADA is also increased in various infectious diseases like Infectious Mononucleosis, Typhoid, Viral Hepatitis, Acute Hepatitis, Alcoholic Hepatic Fibrosis, Chronic Active Hepatitis, Liver Cirrhosis, Hepatoma Initial stages of HIV, and in cases of malignant tumors, the same can be ruled out clinically.