A 30-year-old woman with active SLE presents with new-onset generalised tonic-clonic seizures and acute psychosis without focal neurological deficits. MRI brain is unremarkable and CSF analysis is normal. Which antibody is MOST specifically associated with this neuropsychiatric manifestation?

• A Anti-dsDNA antibodies
• B Anti-Smith antibodies
• C Anti-Ro/SSA antibodies
• D Anti-ribosomal P antibodies ✓

Explanation

Anti-ribosomal P antibodies bind the P0, P1 and P2 phosphoproteins of the ribosomal 60S subunit and are the antibodies most specifically linked to lupus psychosis and depression, likely through neuronal surface binding and calcium influx. Anti-dsDNA correlates with nephritis and complements it diagnostically, while anti-Sm is specific for SLE itself but not for any particular neuropsychiatric phenotype. Normal imaging and CSF support an autoimmune rather than infectious cause here.

Reference: Harrison's Principles of Internal Medicine, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.