What causes high rheumatoid factor with normal anti-O levels?

Rheumatoid factor is an autoantibody commonly detected in patients with rheumatoid arthritis. However, elevated rheumatoid factor with normal anti-O levels may sometimes occur, which could be associated with infections, autoimmune diseases, liver disease, and other conditions. Specific causes are as follows:

1. Infection

Infection is one of the most common reasons leading to elevated rheumatoid factor with normal anti-O levels. Infections can stimulate the immune system to produce antibodies, including rheumatoid factor. Various bacteria and viruses may cause increased levels of rheumatoid factor.

2. Autoimmune diseases

Elevated rheumatoid factor with normal anti-O levels may also indicate an autoimmune disease. For example, patients with systemic lupus erythematosus or Sjögren's syndrome often have high levels of rheumatoid factor.

3. Liver disease

Liver diseases such as hepatitis and cirrhosis may also lead to elevated rheumatoid factor. This is because the liver plays a key role in metabolism and detoxification; when liver function is impaired, it cannot effectively remove waste products and toxins from the body, potentially causing immune system abnormalities.

In addition, genetic factors, drug allergies, acute or chronic phases of illness, and tumors may also result in elevated rheumatoid factor with normal anti-O levels. Patients experiencing symptoms should seek timely medical attention and receive standardized treatment under a doctor’s guidance, which helps promote recovery.