Adenosine Deaminase-(Serum)

Adenosine deaminase (ADA) indicates cellular immune activity and purine metabolism. Elevated ADA in pleural or other body fluids commonly points to tuberculous pleuritis or other infectious/inflammatory conditions and sometimes malignancy. Low or absent ADA activity reflects inherited ADA deficiency causing severe combined immunodeficiency. Clinically, ADA levels help distinguish causes of effusions and assess T‑cell–mediated immune function.

High adenosine deaminase (ADA) levels indicate increased cellular immune activity. In pleural fluid, markedly elevated ADA strongly suggests tuberculous pleuritis; in blood or other fluids, it can reflect active infections, autoimmune inflammation, or lymphoproliferative disorders. Clinically, a high ADA prompts further diagnostic tests (microbiology, imaging, biopsy) to identify the cause and guide appropriate antimicrobial, immunosuppressive, or oncologic treatment.

Adenosine deaminase (ADA) is typically measured in pleural fluid for tuberculous pleuritis; a pleural ADA ≥40 U/L (some labs use 35–40 U/L) strongly suggests TB-related effusion. Serum ADA is not routinely used for TB diagnosis because it lacks consistent sensitivity and specificity; no reliable serum ADA cutoff is established for diagnosing tuberculosis.

Normal adenosine deaminase (ADA) levels depend on the sample. Serum ADA is typically about 8–20 U/L (varies by lab and method). In pleural fluid, ADA is usually below ~40 U/L; pleural ADA ≥40 U/L often raises suspicion for tuberculous pleuritis. Reference ranges differ, so interpret results with clinical context and lab-specific cutoffs.

Treatment for adenosine deaminase (ADA) deficiency includes enzyme replacement therapy (weekly PEG‑ADA), definitive immune reconstitution via hematopoietic stem cell transplantation (preferably an HLA‑matched donor), and emerging autologous gene therapy to correct the ADA gene. Supportive care—immunoglobulin replacement, antimicrobial prophylaxis, and infection control—is essential. Early diagnosis and specialist immunology referral optimize outcomes.

Yes — tuberculosis is usually curable with timely, appropriate antibiotic treatment. Drug-sensitive TB is treated with a combination of antibiotics for at least six months; strict adherence is essential. Drug-resistant TB requires longer, specialized regimens and can be harder to treat but often remains curable with second-line drugs and expert management. Untreated TB can be severe or fatal, so prompt diagnosis and completion of therapy are critical.