Figure 1.
IgA nephropathy was diagnosed in 436 patients between January 2000 and December 2008. Excluding 93 patients, a total of 343 patients were enrolled. eGFR, estimated glomerular filtration rate; GN, glomerulonephritis; SLE, systemic lupus erythematosus.
Figure 2.
Representative pictures of immunofluorescence staining of mesangial C3 1+ to 3+.
Immunofluorescence intensity was quantified by ImageJ software.
Figure 3.
A scattered plot of each level of serum C3 between patients with C3 levels <90 mg/dl and patients with C3 levels ≥90 mg/dl.
Table 1.
Demographic, clinical and biochemical characteristics.
Figure 4.
The histopathologic grades such as (A) mesangial hypercellularity, (B) segmental glomerulosclerosis, (C) endocapillary hypercellularity, and (D) tubular atrophy/interstitial fibrosis according to mesangial C3 deposition.
Mesangial hypercellularity (C3 deposition 0, 9.4%; 1+, 29.7%; 2+∼3+, 49.3%; P<0.001) and high-grade tubular atrophy/interstitial fibrosis (C3 deposition 0, 7.5%; 1+, 10.5%; 2+∼3+, 14.1%; P<0.001) were more prominent as the mesangial area of C3 deposition increased.
Figure 5.
Comparison of serum C3 levels according to mesangial C3 deposition.
Serum C3 levels decreased significantly from 0 to 2+∼3+ mesangial C3 deposition (0, 111.7±18.0; 1+, 104.3±17.1; 2+∼3+, 98.6±14.2 mg/dl; P<0.001).
Table 2.
Comparison of histopathologic features from renal biopsies between patients with and without decreased C3 levels.
Figure 6.
Kaplan-Meier analyses of cumulative renal survival of patients with IgA nephropathy based on (A) serum C3 level and (B) mesangial C3 deposition.
(A) A 10-year renal survival rate was significantly lower in patients with C3 levels <90 mg/dl than those with C3 levels ≥90 mg/dl (P = 0.006). (B) A 10-year survival in patients with 2+ and 3+ mesangial deposition of C3 was lower than in those without C3 deposition (P = 0.04).
Figure 7.
ROC curve analysis for renal outcome of the doubling of the baseline serum creatinine.
Serum C3 levels had a significant predictive value for renal outcome (AUC = 0.642, P = 0.011), although the predictive value of serum C3 was lower than UPCR (AUC = 0.819, P<0.001) or eGFR (AUC = 0.781, P<0.001).
Figure 8.
Kaplan-Meier analyses of cumulative renal survival of patients with IgA nephropathy according to histopathologic features including (A) mesangial hypercellularity, (B) segmental glomerulosclerosis, (C) endocapillary hypercellularity, and (D) tubular atrophy/interstitial fibrosis.
Patients with mesangial hypercellularity, segmental glomerulosclerosis, endocapillary hypercellularity, and tubular atrophy/interstitial fibrosis had significantly lower renal survival than those without such findings (P<0.05).
Table 3.
Incidence of patients with doubling of serum creatinine and ESRD according to decreased C3 levels and mesangial C3 deposition.
Table 4.
Cox regression models for renal outcome of the doubling of the baseline serum creatinine.
Figure 9.
The decline rate of eGFR. Error bars indicate standard error.