Adenosine Deaminase (ADA), Serum

What it is:
This test measures the level of adenosine deaminase (ADA), an enzyme involved in purine metabolism, in the blood (serum). ADA plays a role in lymphocyte function, and abnormal levels can indicate immune or infectious diseases.

Uses

• Aid in the diagnosis of tuberculosis (TB), especially when extrapulmonary TB is suspected

• Evaluate immune system activity in certain infections and autoimmune conditions

• Support diagnosis or monitoring of hematological malignancies (e.g., leukemia, lymphoma)

Symptoms That May Lead to the Test

• Persistent fever, weight loss, or night sweats

• Chronic cough or chest pain

• Enlarged lymph nodes

• Signs of systemic infection or immune dysfunction

Abnormal Results

• High ADA levels:

  • Tuberculosis (pulmonary or extrapulmonary)

  • Other bacterial or viral infections

  • Certain lymphomas or leukemias

  • Autoimmune disorders (e.g., rheumatoid arthritis, lupus)

• Low ADA levels:

  • Rarely clinically significant, but may suggest severe immunodeficiency

Risks

• Minimal, limited to standard risks of a blood draw (mild pain, bruising, or dizziness).