A 28-year-old woman comes to the physician for a 2-month history of fatigue, joint pain, and foamy urine. She also reports facial puffiness in the morning and occasional shortness of breath. BP is 150/90. Physical exam shows mild periorbital edema and trace pedal edema. Urinalysis shows 3+ protein, 2+ blood, and dysmorphic RBCs. Anti-Smith antibodies are positive. Complement protein C3 is low. Platelet count is 100,000/μL. Which of the following is most likely to be seen in this patient?
Anti-glomerular basement membrane antibodies causing linear IgG deposition
Immune complex deposition in the mesangium following mucosal antigen exposure
Immune complex deposition in the subendothelial space with complement activation
Immune complex deposition in the subepithelial space with lumpy bumpy appearance
T-cell–mediated podocyte effacement without immune complex deposition
