Kidney Specialist Inc.
Sheikh Mohammad Masood, MD • Mohammed M. Siddiqui, MD
451 E Almond Ave, Suite 101, Madera, CA 93637 • 6777 N. Willow Ave, Fresno, CA 93710
Phone: (559) 661-1965 | Fax: (559) 661-1952
Antinuclear Antibodies (ANA Test)
Clinical patient guide explaining immune autoantibodies, ANA titer interpretation, autoimmune conditions, and kidney protection.
What are antinuclear antibodies (ANA)?
Antinuclear antibodies (often called "ANA") are proteins produced by your body's immune system. Normally, the immune system makes antibodies to protect your body and fight off infections caused by foreign invaders like bacteria or viruses.
In autoimmune diseases, however, the immune system makes a mistake: it attacks the body's own healthy cells and tissues. Antinuclear antibodies are autoantibodies that specifically attack substances inside the nucleus of normal cells (the cellular "command center").
What organs of the body can be affected?
Autoimmune disorders associated with ANA autoantibodies can cause inflammation in multiple body systems:
Lupus nephritis, glomerular inflammation, protein leakage (proteinuria), blood in urine (hematuria), and reduced filtration.
Autoimmune destruction of red blood cells (anemia), low platelets (thrombocytopenia), or low white blood cell counts.
Malar rash (butterfly rash across cheeks/nose), discoid lesions, photosensitivity to sun, and mouth sores.
Inflammatory arthritis, morning stiffness, joint swelling, muscle inflammation (polymyositis), and generalized weakness.
Pleuritis (painful breathing), pleural effusion (fluid around lungs), and interstitial pulmonary inflammation.
Headaches, cognitive changes, peripheral neuropathy (numbness/tingling in hands and feet), and central inflammation.
Autoimmune Diseases Associated with a Positive ANA
A positive ANA test may be associated with several systemic autoimmune conditions:
A chronic multi-organ autoimmune disease frequently affecting kidneys (lupus nephritis), skin, joints, and blood cells.
A condition causing hardening and thickening of skin, connective tissues, and blood vessels, with potential renal crisis.
An autoimmune condition featuring overlapping clinical signs of lupus, scleroderma, and polymyositis with high anti-RNP antibodies.
Inflammatory muscle disorders causing proximal muscle weakness, fatigue, and characteristic skin rashes around eyelids and knuckles.
A systemic inflammatory autoimmune condition primarily causing chronic symmetric joint destruction and systemic inflammation.
ANA Titer & Test Result Interpretation
Core clinical principle: "The higher the number (called the titer), the greater the chance of autoimmune disease."
| Titer Result | Clinical Level | Clinical Interpretation |
|---|---|---|
| Negative (< 1:40) | Normal / Non-reactive | Indicates you probably do not have a systemic autoimmune disease. Normal baseline finding. |
| 1:40 | Low / Trace Positive | Common in healthy individuals (up to 20-30% of healthy population). Rarely indicates active autoimmune disease. |
| 1:80 | Borderline Positive | Borderline level. May be non-specific or indicate early immune activation. Physician correlates with physical symptoms. |
| 1:160 | Clinically Significant Positive | Moderate titer. Clinically significant cutoff where autoimmune evaluation and sub-antibody panel are recommended. |
| 1:320 or higher (1:640+) | Strongly Positive | High titer. High probability of systemic autoimmune disease (such as Lupus, Scleroderma, or MCTD). Requires specialist care. |
Clinical Caveat: Infections & Temporary Immune Responses
Having a positive ANA test does NOT automatically mean you have a chronic autoimmune disease. Some people have a positive ANA caused by a temporary viral or bacterial infection, certain prescription medications, or normal aging. A positive ANA test must always be correlated by a specialist with your physical symptoms and confirmatory lab tests.
Nephrology Clinical Focus: Lupus Nephritis & Kidney Biopsy
Nephrologists (such as Dr. Masood and Dr. Siddiqui) frequently order ANA testing when evaluating unexplained protein in the urine (proteinuria), blood in the urine (hematuria), or an unexplained drop in glomerular filtration rate (GFR).
Confirmatory tests: anti-dsDNA (highly specific for lupus nephritis), anti-Smith (anti-Sm), anti-RNP, and complement C3/C4 levels.
If lupus nephritis is suspected, a tiny sample of kidney tissue is examined under a microscope to classify the disease stage and guide targeted therapy.
Questions About Your ANA Test or Kidney Health?
Schedule a consultation with Dr. Masood or Dr. Siddiqui.