Table 2.
Associations of plasma galactose-deficient IgA1/C3 ratio with CKD progression
| Galactose-Deficient IgA1/C3 Levels (U/mg, range) | No. at Risk | Events (Incidence Rate)a | Hazard Ratio (95% Confidence Interval) | ||||||
|---|---|---|---|---|---|---|---|---|---|
| Composite End Pointb | ESKD | 50% eGFR Decline | Unadjusted | Model 1c | Model 2d | Model 3e | |||
| CKD progression event per ln (galactose-deficient IgA1/C3) | 123.2–982.3 | 1210 | 172 (3.1) | 114 (2.0) | 165 (3.0) | 2.90 (1.80 to 4.67) | 2.92 (1.8 to 4.72) | 2.31 (1.47 to 3.64) | 2.03 (1.25 to 3.29) |
| Galactose-deficient IgA1/C3 quartiles | |||||||||
| 1 | 123.2–268.4 | 303 | 24 (1.7) | 18 (1.3) | 22 (1.6) | 1 (Reference) | 1 (Reference) | 1 (Reference) | 1 (Reference) |
| 2 | 268.7–322.3 | 302 | 41 (3.0) | 22 (1.5) | 39 (2.8) | 1.60 (0.97 to 2.66) | 1.52 (0.91 to 2.53) | 1.59 (0.95 to 2.66) | 1.71 (1.01 to 2.89) |
| 3 | 322.4–386.9 | 302 | 45 (3.2) | 28 (2.0) | 43 (3.1) | 1.83 (1.12 to 3.01) | 1.72 (1.04 to 2.84) | 1.89 (1.14 to 3.12) | 1.55 (0.91 to 2.63) |
| 4 | 387.2–982.3 | 303 | 62 (4.4) | 46 (3.1) | 61 (4.3) | 2.55 (1.59 to 4.1) | 2.51 (1.57 to 4.03) | 2.28 (1.41 to 3.66) | 2.17 (1.33 to 3.56) |
| P for trendf | <0.001 | <0.001 | <0.001 | <0.001 | <0.001 | 0.001 | 0.003 | ||
Annual incidence rate of events per 100 participants.
CKD progression event was defined as a 50% decline in eGFR or ESKD. The events are not mutually exclusive.
Model 1 was adjusted for sex and age. Sex was analyzed as dichotomous data.
Model 2 was adjusted for covariates in model 1 plus eGFR, proteinuria, and hypertension (yes or no).
Model 3 was adjusted for covariates in model 2 plus Oxford M (mesangial hypercellularity), E (the presence of endocapillary proliferation), S (segmental glomerulosclerosis/adhesion), T (severity of tubular atrophy/interstitial fibrosis), and C (presence of crescent) scores and steroids or other immunosuppressive agents (yes or no).
Test for trend of composite end point, ESKD or 50% eGFR decline across quartiles of galactose-deficient IgA1/C3 levels according to the Cochran–Armitage trend test. Test for trend in Cox regression models according to the variable containing the median value for each quartile.