How to diagnosis the cause of CKD?
An attempt should be made to obtain a specific kidney diagnosis. The first step in this process is a careful urinalysis, looking for proteinuria, hematuria, and cellular casts.
Further evaluation may include quantification of proteinuria, kidney ultrasound, referral to a nephrologist, and a kidney biopsy. The biopsy can be done as an outpatient and has a relatively low complication rate.
The kidney tissue is examined by light, immunofluorescent, and electron microscopy. Serum and urine electrolytes may be used to assess for renal tubular disorders, and serum and urine immunofixation can be performed to rule out a monoclonal protein.
If glomerulonephritis is suspected, further evaluation could include hepatitis serology, ANCA, anti-GBM antibodies, antinuclear antibodies, and anti–double-stranded DNA.
