Which autoimmune disease is associated with anti-dsDNA and anti-Smith antibodies and lupus nephritis?

Which autoimmune disease is associated with anti-dsDNA and anti-Smith antibodies and lupus nephritis?

• A. Systemic sclerosis
• B. Rheumatoid arthritis
• C. Sjogren syndrome
• D. Systemic lupus erythematosus (SLE)

Answer: (D)

Anti-dsDNA antibodies and anti-Smith antibodies are highly specific for systemic lupus erythematosus, and their presence strongly points to this disease. Anti-dsDNA levels often track with disease activity and are especially linked to lupus nephritis, where immune complex deposition in the kidneys drives inflammation. Anti-Smith antibodies are also very specific for SLE, though not always present in every patient; when they are positive, they support the diagnosis. Other autoimmune diseases have different characteristic antibodies, which helps distinguish them: systemic sclerosis is typically associated with antibodies to topoisomerase I (Scl-70) or centromere; rheumatoid arthritis with anti-CCP and rheumatoid factor; Sjögren syndrome with anti-Ro/SSA and anti-La/SSB. These do not explain the combination of anti-dsDNA and anti-Smith. Thus, the pattern of anti-dsDNA and anti-Smith antibodies, along with lupus nephritis, best fits systemic lupus erythematosus.

Anti-dsDNA antibodies and anti-Smith antibodies are highly specific for systemic lupus erythematosus, and their presence strongly points to this disease. Anti-dsDNA levels often track with disease activity and are especially linked to lupus nephritis, where immune complex deposition in the kidneys drives inflammation. Anti-Smith antibodies are also very specific for SLE, though not always present in every patient; when they are positive, they support the diagnosis.

Other autoimmune diseases have different characteristic antibodies, which helps distinguish them: systemic sclerosis is typically associated with antibodies to topoisomerase I (Scl-70) or centromere; rheumatoid arthritis with anti-CCP and rheumatoid factor; Sjögren syndrome with anti-Ro/SSA and anti-La/SSB. These do not explain the combination of anti-dsDNA and anti-Smith.

Thus, the pattern of anti-dsDNA and anti-Smith antibodies, along with lupus nephritis, best fits systemic lupus erythematosus.