From the Research
C4a Test and Lyme Disease
- The C4a test has been studied as a potential marker for Lyme disease, with some studies suggesting its usefulness in diagnosing and monitoring the disease 1, 2.
- Elevated levels of C4a have been found in patients with acute Lyme disease, particularly those with musculoskeletal symptoms 1, 2.
- The C4a test may be useful in monitoring response to antibiotic therapy in patients with chronic Lyme disease, as decreases in C4a levels have been associated with positive treatment outcomes 1.
- However, other studies have noted that two-tiered testing remains the gold standard for diagnosing Lyme disease, and that other laboratory tests may be more appropriate for diagnosis 3.
- Complement fixation tests, including those measuring C4a, have been explored as potential diagnostic tools for Lyme disease, but their utility is still being researched 4, 5.
Key Findings
- Patients with chronic Lyme disease and musculoskeletal symptoms tend to have increased C4a levels 1.
- C4a levels may decrease in response to antibiotic therapy in patients with chronic Lyme disease 1.
- Elevated C4a levels have been found in patients with acute Lyme disease, particularly those with erythema migrans skin rash 2.
- Complement split products, including C4a, may be useful markers of Lyme disease in patients seen shortly after tick bite 2.