What is the role of blood tests in the workup of pediatric nephrotic syndrome?

Updated: Mar 04, 2020
  • Author: Jerome C Lane, MD; Chief Editor: Craig B Langman, MD  more...
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Serum albumin levels in nephrotic syndrome are generally less than 2.5 g/dL. Values as low as 0.5 g/dL are not uncommon.

Lipid panel findings are typically as follows:

  • Elevated total cholesterol, low-density lipoprotein (LDL)-cholesterol

  • Elevated triglycerides with severe hypoalbuminemia

  • High-density lipoprotein (HDL)-cholesterol (normal or low)

The patient with INS, even MCNS, can present with acute kidney failure as a result of intravascular volume depletion or bilateral renal vein thrombosis. Elevated BUN and creatinine levels and signs of chronic kidney failure (such as poor growth, anemia, acidosis, hyperkalemia, hyperphosphatemia, and elevated parathyroid hormone) suggest a chronic glomerular disease other than MCNS, such as one of the following:

Serum sodium levels are low in patients with INS because of hyperlipidemia (pseudohyponatremia), as well as dilution due to water retention. Total calcium levels are low because of hypoalbuminemia, but ionized calcium levels are normal.

On the CBC count, an increased hemoglobin level and hematocrit indicate hemoconcentration and intravascular volume depletion. The platelet count is often increased.

HIV, hepatitis B virus, and hepatitis C virus are important secondary causes of nephrotic syndrome. Consequently, screening for these viruses should be performed in all patients who present with nephrotic syndrome. Consider checking liver enzymes, such as alanine aminotransferase (ALT) and aspartate aminotransferase (AST), when screening for liver disease.

Low complement levels (C3, C4) are found in postinfectious glomerulonephritis, C3 glomerulonephritis/MPGN, and lupus nephritis.

ANA and anti–double-stranded DNA antibody assays are used to screen for collagen-vascular disease in patients with systemic symptoms (fever, rash, weight loss, joint pain) or in any patient with nephrotic syndrome who presents in later school-age or adolescent years when the incidence of lupus is higher.

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