Long-term investigation of kidney ultrasound in cases of hemolytic uremic syndrome in children.

Purpose: The aim is to describe the changes in initial findings of kidney ultrasound examinations in cases of hemolytic uremic syndrome (HUS) in children and to evaluate the respective importance of three sonographical parameters: echogenicity, corticomedullary differentiation (CMD), and kidney size. The correlation with laboratory parameters and proteinuria is analysed.

Methods: Reports containing ultrasound examinations and laboratory values from 1989 through 2012 of 39 children (13 cases of atypical HUS and 26 cases of typical HUS, first diagnosis at age 4 months to 10 2/12 years) suffering from HUS were analysed retrospectively. Ultrasound scans of the right kidney (n = 312) were evaluated with regard to the factors echogenicity, CMD, and kidney volume (ml, percentile). Laboratory parameters included serum creatinine, endogenous creatinine clearance in 24-h urine collection, eGFR according to Schwartz, and the protein content of the 24-h urine collection.

Results: All patients initially had increased echogenicity of the kidneys. All kidney volumes were ranged in the higher percentiles (the median percentile was the 85th). For assessment of long-term progression, the echogenicity proved to be of higher importance than the CMD due to a significant correlation between laboratory parameters of kidney function and the echogenicity.

Conclusion: Ultrasound examination of the kidneys is an important method in follow-up examinations of patients with HUS. Renal morphology correlates with laboratory parameters of kidney function.