Estimating and Managing Glomerular Filtration Rate in Children

Recommended GFR Estimation Methods for Children

For children with low muscle mass, cystatin C-based GFR measurements are preferred as creatinine-based equations may overestimate kidney function 2, 3
Combined creatinine and cystatin C-based equations provide superior accuracy, especially in children with solitary functioning kidneys 3

Enzymatic creatinine assays should be used in children rather than Jaffe assays due to the higher relative contribution of non-creatinine chromogens in pediatric samples 3, 4
Laboratories measuring creatinine in infants or small children must ensure their quality control process includes the lowest end of the expected range of values 4
An eGFRcr level <90 ml/min per 1.73 m² should be flagged as "low" in children and adolescents over 2 years of age 4

The trend of GFR assessments over time is more relevant than a single measurement, especially in growing children 5
GFR should be assessed periodically and correlated with somatic growth goals to evaluate progression and need for renal replacement therapy 5
For children with chronic kidney disease, monitoring should include assessment of albuminuria alongside GFR measurements 4, 6
In children with tuberous sclerosis complex or other conditions affecting muscle mass, cystatin C-based eGFR measurements are recommended 2

For children with rapid progression (sustained decline in eGFR >5 ml/min/1.73 m²/year), more frequent monitoring and specialist referral are recommended 5
For children with polycystic kidney disease or other genetic kidney disorders, regular monitoring of GFR is essential for early intervention 7