Anti-Hu Antibody (ANNA-1) – What Your Lab Result Means
What is Anti-Hu?
Anti-Hu antibodies (also called ANNA-1, or anti-neuronal nuclear antibody type 1) are a type of autoantibody—a protein made by your immune system that mistakenly attacks your own body’s cells. Specifically, Anti-Hu targets parts of the nervous system. Its presence in the blood may be a sign of an autoimmune neurological disorder often linked to certain types of cancer.
Why Is This Marker Important?
Anti-Hu antibodies are commonly associated with paraneoplastic neurologic syndromes (PNS)—a group of rare disorders that occur when the immune system reacts to a hidden (occult) tumor by attacking the nervous system. These antibodies are most often linked to small cell lung cancer, but may also be found in people with other cancers such as prostate, breast, or ovarian cancer.
What a Positive Anti-Hu Result May Indicate:
-
An autoimmune attack on the nervous system
-
A potential underlying cancer (especially small cell lung cancer)
-
Neurological symptoms such as:
-
Memory loss
-
Seizures
-
Muscle weakness
-
Numbness or tingling
-
Difficulty walking or speaking
-
What a Negative Result Means:
A negative Anti-Hu result means this specific antibody was not found in your blood. However, it does not rule out other autoimmune or cancer-related causes of neurological symptoms. If symptoms persist, your doctor may recommend further testing with other paraneoplastic antibody panels.
What to Do Next:
If your Anti-Hu result is positive, your healthcare provider may order imaging studies (such as a CT scan or PET scan) and refer you to a neurologist or oncologist. Early detection and treatment of the underlying cause—whether it’s a tumor or an autoimmune disorder—can significantly improve outcomes.
In Summary:
A positive Anti-Hu antibody test may be an early warning sign of an autoimmune condition affecting the nervous system, often linked to cancer. It’s an important clue that can help guide further evaluation and diagnosis.
Anti-Hu Ab
Every lab result you’ve ever had, charted and explained.
Healthmatters is a tracker for your lab results. Upload a report from any lab, any country — every marker charted and explained.
Start with my report →
All our content is backed by peer-reviewed studies, academic research, and trusted medical sources. We’re committed to accuracy and transparency — see our editorial policy for details.