What is the clinical significance of dsDNA antibody positivity with hypocomplementemia in systemic lupus erythematosus?

• A. dsDNA positivity with low C3/C4 supports active SLE and correlates with nephritis.
• B. dsDNA positivity with low C3/C4 indicates inactive disease.
• C. dsDNA positivity is not related to disease activity.
• D. dsDNA positivity defines an unrelated autoimmune condition.

Answer: (B)

Anti-dsDNA antibodies that appear with low C3 and C4 levels point to active SLE due to immune complex formation driving complement consumption. The immune complexes deposit in tissues—most notably the kidneys—activating the classical complement pathway and lowering circulating complements. This pattern is strongly associated with disease flares and lupus nephritis, signaling the need for closer monitoring and potential adjustment of therapy. In contrast, inactive disease would more likely show normal complement levels and stable or lower dsDNA titers, so the combination described does not indicate inactivity or an unrelated condition.