Is there really an increase in non-minimal change nephrotic syndrome in children?
BACKGROUND
Reports on the worldwide increase in focal segmental glomerulosclerosis (FSGS) in childhood may have been hampered by referral bias. A true increase in FSGS possibly could alter the current practice of withholding renal biopsy in childhood nephrotic syndrome (NS) unless the patient fails to respond to a 28-day course of corticosteroid therapy.


METHODS
With these questions in mind, we analyzed a 17-year database covering a 275,000-child population with mandatory referral. The incidence of NS per 100,000 childhood population per year was calculated, charts of 159 patients with NS seen between 1985 and 2002 were reviewed, and a receiver operating characteristic (ROC) plot analysis was performed to analyze the diagnostic performance of remission time.


RESULTS
Results show that 115 of 159 patients had minimal change NS, diagnosed either on the basis of corticosteroid response (n = 89), verified by renal biopsy (n = 14), or with minimal change plus mesangial immunoglobulin M on histological examination (n = 12). The remaining 44 patients underwent a renal biopsy showing FSGS (n = 29; 18.2%), diffuse mesangial hypercellularity (n = 8; 5%), membranoproliferative glomerulonephritis (n = 1; 0.6%), membranous nephropathy (n = 3; 1.9%), or other diagnoses (n = 3). The incidence of FSGS increased significantly (P = 0.0253) from 0.37 to 0.94/100,000-child population/y in the two 8(1/2)-year intervals of our study. ROC plot analysis confirmed diagnostic sensitivity and specificity greater than 80% for remission time between 21 and 28 days of therapy.


CONCLUSIONS
We confirm the increasing incidence of FSGS in children with idiopathic NS in a well-defined catchment area and, at the same time, find no reason to change the initial therapy and current indications to perform renal biopsy in childhood NS.
Filler
Guido
G
Division of Pediatric Nephrology, Department of Pediatrics and Laboratory Medicine, Children's Hospital of Eastern Ontario, University of Ottawa, Ottawa, Canada. filler@cheo.on.ca
Young
Elizabeth
E
Geier
Pavel
P
Carpenter
Blair
B
Drukker
Alfred
A
Feber
Janusz
J
D000293:Adolescent; D000305:Adrenal Cortex Hormones / Q000627:therapeutic use; D000328:Adult; D001706:Biopsy / Q000706:statistics & numerical data; D002391:Catchment Area, Health; D002648:Child; D002675:Child, Preschool; D005260:Female; D005920:Glomerular Mesangium / Q000276:immunology / Q000473:pathology; D015432:Glomerulonephritis, Membranoproliferative / Q000150:complications / Q000453:epidemiology; D015433:Glomerulonephritis, Membranous / Q000150:complications / Q000453:epidemiology; D005923:Glomerulosclerosis, Focal Segmental / Q000150:complications / Q000453:epidemiology*; D006801:Humans; D007075:Immunoglobulin M / Q000032:analysis; D015994:Incidence; D007223:Infant; D007668:Kidney / Q000473:pathology; D008297:Male; D009402:Nephrosis, Lipoid / Q000150:complications / Q000188:drug therapy / Q000453:epidemiology; D009404:Nephrotic Syndrome / Q000453:epidemiology* / Q000209:etiology; D012372:ROC Curve; D012074:Remission Induction; D012189:Retrospective Studies; D012680:Sensitivity and Specificity
D000305:Adrenal Cortex Hormones; D007075:Immunoglobulin M