Anti-Carbonic Anhydrase I Antibody (Serum) – Immunoassay
This test measures antibodies against carbonic anhydrase I, a protein found in certain tissues. It may be used to evaluate autoimmune conditions or rare enzyme-related disorders.
["This test helps identify potential autoimmune responses or enzyme dysfunctions linked to carbonic anhydrase I."]
Key facts at a glance
- LOINC
- 34717-9
- Short code
- COX2IGG
- Synonyms
- C burnet Ph2 IgG Titr Ser IF
- Category
- chemistry
- Sample
- serum
- Container
- Serum separator tube (SST) or red-top tube without anticoagulant
- Units
- N/A
- Ref low
- 0
- Ref high
- 1
- Critical range
- — – 800 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- Immunofluorescence assay (IFA)
- CPT
- 86638
- SNOMED
- 5875009
- Specimen volume
- 1–2 mL serum (minimum 0.5 mL)
- Stability
- Serum stable at room temperature for 8 hours; refrigerated at 2–8°C for 7 days; frozen at -20°C or below for up to 30 days. Avoid repeated freeze-thaw cycles.
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 24–72 hours
- Order
- routine
What Does This Test Measure?
The test detects the presence of antibodies directed against carbonic anhydrase I, a protein enzyme involved in metabolic processes. Carbonic anhydrase I is primarily expressed in certain tissues, including the kidney and blood vessels, and plays a role in maintaining acid-base balance and fluid transport. Antibodies against this enzyme may indicate an autoimmune reaction or a rare inherited condition.
Why Might This Test Be Ordered?
Your healthcare provider may order this test if you have symptoms or conditions linked to autoimmune diseases (e.g., certain connective tissue disorders) or if carbonic anhydrase I-related enzyme deficiencies are suspected. It may also be part of a broader evaluation for unexplained metabolic or renal issues.
What Does a Positive Result Mean?
A positive result suggests the presence of antibodies against carbonic anhydrase I, which could indicate an autoimmune response. However, further testing and clinical correlation are needed to determine the underlying cause. Some conditions, like certain enzyme deficiencies, may also be associated with abnormal antibody levels.
Sample Collection and Preparation
This test uses a blood sample drawn from a vein (venipuncture). The blood is processed into serum for analysis. Avoid alcohol consumption for 24 hours before testing, as it may affect test results.
Reference range
Negative: <1:16; Equivocal: 1:16–1:64; Positive: ≥1:128. Phase 2 IgG titers indicate past exposure or chronic Q fever when markedly elevated (≥1:800).N/A
No fasting required. No special patient preparation needed prior to specimen collection.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
Anti-Carbonic Anhydrase I (CAI) Antibody
Frequently asked questions
What does this test measure exactly?
Is this test commonly used for routine health checks?
How long does it take to get results?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
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Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy