C3 nephritic factor associated with C3 glomerulopathy in children.
BACKGROUND
C3 glomerulopathy (C3G) is characterized by predominant C3 deposits in glomeruli and dysregulation of the alternative pathway of complement. Half of C3G patients have a C3 nephritic factor (C3NeF). C3G incorporated entities with a range of features on microscopy including dense deposit diseases (DDD) and C3 glomerulonephritis (C3GN). The aim of this work was to study children cases of C3G associated with C3NeF.


METHODS
We reviewed 18 cases of C3G with a childhood onset associated with C3NeF without identified mutations in CFH, CFI, and MCP genes.


RESULTS
Clinical histories started with recurrent hematuria for seven patients, nephrotic syndrome for four, acute post-infectious glomerulonephritis for three and acute renal failure for four. Twelve patients had a low C3 at first investigation. Kidney biopsy showed ten C3GN and eight DDD. Twenty-three percent of the patients tested presented elevated sC5b9. Seven patients relapsed 3 to 6 years after the onset. At the end of follow-up, two patients were under dialysis, 11 had a persistent proteinuria, five had none; four patients did not follow any treatment. Steroids were first used in 80 % of cases.


CONCLUSIONS
C3NeF associated C3G has a heterogeneous presentation and outcome. Anti-proteinuric agents may control the disease during follow-up, even after nephrotic syndrome at the onset. The efficiency of immunosuppressive therapy remains questionable.
Department of Pediatrics, Nephrology unit, CHU de Reims, Reims, France.
Camille
C
Nicolas
Vincent
V
Vuiblet
Veronique
V
Baudouin
Marie-Alice
MA
Macher
Isabele
I
Vrillon
Nathalie
N
Biebuyck-Gouge
Maud
M
Dehennault
Sophie
S
Gié
Denis
D
Morin
Hubert
H
Nivet
François
F
Nobili
Tim
T
Ulinski
Bruno
B
Ranchin
Maria Chiarra
MC
Marinozzi
Stéphanie
S
Ngo
Véronique
V
Frémeaux-Bacchi
Christine
C
Pietrement
D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D003178:Complement C3 Nephritic Factor / Q000378:metabolism*; D005260:Female; D005921:Glomerulonephritis / Q000378:metabolism / Q000473:pathology / Q000628:therapy; D015432:Glomerulonephritis, Membranoproliferative / Q000378:metabolism* / Q000473:pathology* / Q000628:therapy; D006801:Humans; D007223:Infant; D008297:Male; D012189:Retrospective Studies
D003178:Complement C3 Nephritic Factor