A 34-year-old female is brought to the emergency room by EMS after a seizure during dinner. Her past medical history includes arthritis, which has developed in the last few years. On a recent visit to her family physician for complaints of fatigue, she was found to have a serum leukocyte count of 3.3 × 109/L and a urine dipstick positive for protein, but negative for leukocyte esterase and glucose. Of the following, which is the most likely mechanism for the protein in her urine?
An undiagnosed neoplasm
A urinary tract infection
Antibodies directed against the basement membrane
Deposition of antigen-antibody complexes in the glomeruli
Answer : D Deposition of antigen-antibody complexes in the glomeruli
Of the choices, the most likely diagnosis is systemic lupus erythematosus, as it can cause fatigue, arthritis, leukopenia, and seizures, whereas none of the other conditions would cause all of these signs and symptoms.
The mechanism of glomerular injury in systemic lupus is deposition of immune complexes in the glomerulus