Which of the following is NOT routinely considered as part of a renal screen in the investigation of new-onset renal failure?

c. Caeruloplasmin and serum copper are useful tests in the investigation of liver disease of unknown aetiology and are sensitive indicators of the presence of Wilson’s disease (hepatolenticular degeneration). 

A renal ultrasound scan is useful to identify any obstruction, scarring from previous infection or altered renal size indicative of long-term renal damage or chronically reduced renal blood flow. Safe and non-invasive to perform this should always be considered in the investigation of renal disease. Complement levels (C3 and C4) as well as double-stranded DNA (dsDNA) and erythrocyte sedimentation rate (ESR) should be used as a screen for systemic lupus erythematosus (SLE, lupus) nephritis. Generally, an elevated ESR and anti-dsDNA and low C3 and C4 levels are associated with active nephritis. Anti-neutrophil cytoplasmic antibodies (ANCA) are useful in the detection of vasculitic diseases affecting the kidney such as Wegener’s granulomatosis and Churg–Strauss disease among many. Bence–Jones protein (light-chain fragment) is a simple and effective screening tool for suspected myeloma with associated light-chain nephropathy and should never be omitted from the diagnostic work-up of renal failure.