We should look for complement-mediated diseases in patients like this one with nephritic syndrome. In this case, complements are normal with C3 109 mg/dL (ref: 90 – 180 mg/dL) and C4 14 mg/dL (ref: 10 – 40 mg/dL)

HIV nephropathy is more likely to present with a nephrotic rather than nephritic syndrome, so this may be low yield. Try another test!

This is a low yield test given this patient’s presentation. Further, this is not a sensitive or specific test though it has been traditionally used to look for acute interstitial nephritis.

Diabetic nephropathy is unlikely to present with a nephritic  as our patient has here. Try again!

You call the lab, and the result for this test will take 1 week. We’ll have to move on for now and try another test.

1:60 (reference: less than 1:80). Systemic lupus erythematosus (SLE) nephritis is possible given this patient’s nephritic syndrome, but this clinical presentation makes other diagnoses more likely.

Hepatitis C-associated glomerulonephritis can definitely present like this. The antibody test is negative.

The c-ANCA titer is elevated, the p-ANCA titer is within normal limits. 

Patients with monoclonal gammopathies and kidney disease typically present with nephrotic syndrome – this is likely a low yield test for now Choose another!