Anti Smith IgG Antibody by ELISA, Serum

Anti Smith (Sm) IgG Antibody by ELISA, Serum

Test Overview

The Anti Smith (Sm) IgG Antibody by ELISA test detects IgG antibodies against the Smith (Sm) antigen in the blood. These autoantibodies are highly specific for Systemic Lupus Erythematosus (SLE) and are used to support the diagnosis of lupus when combined with clinical findings and other autoimmune tests.

Why is this test done?

• Helps diagnose Systemic Lupus Erythematosus (SLE)
• Supports evaluation of autoimmune connective tissue disorders
• Assists in confirming lupus in patients with positive ANA results
• Helps differentiate SLE from other autoimmune diseases

Symptoms that may require this test

• Persistent joint pain and swelling
• Skin rashes, especially butterfly-shaped facial rash
• Unexplained fever
• Fatigue and weakness
• Mouth or nose ulcers
• Hair loss
• Sensitivity to sunlight
• Kidney-related symptoms or swelling

Sample Required

• Sample Type: Serum
• Method: ELISA (Enzyme-Linked Immunosorbent Assay)

Preparation

• No fasting is generally required.
• Inform your doctor about any medications or ongoing autoimmune treatment.

Interpretation

• Positive: Anti-Sm IgG antibodies detected, strongly supporting the diagnosis of SLE when correlated with clinical findings.
• Negative: Anti-Sm antibodies not detected. A negative result does not completely rule out lupus, as not all SLE patients produce these antibodies.

Who should consider this test?

• Individuals with symptoms suggestive of lupus
• Patients with positive ANA test results
• Those being evaluated for autoimmune connective tissue diseases
• Patients referred by a rheumatologist for autoimmune workup

Benefits

• Highly specific marker for Systemic Lupus Erythematosus (SLE)
• Supports early and accurate diagnosis
• Helps differentiate lupus from other autoimmune disorders
• Reliable ELISA-based testing with accurate results

Note: Test results should always be interpreted by a qualified physician along with clinical symptoms, ANA, Anti-dsDNA, complement levels, and other laboratory findings.