Serum Levels of Joining Chain-Containing IgA1 Are Not Elevated in Patients with IgA Nephropathy

Table 1

Demographic and clinical features of patients with IgA nephropathy and healthy subjects.

Characteristics	IgAN	NC
Patient number	115	117
Mean age (yr)	35 (30-43)	37 (27-48)
Male, (%)	58 (50.4)	46 (39.3)
24-hour urine protein excretion (g/24 h)	0.63 (0.26-1.44)
<0.3	32 (27.8%)
0.3-0.99	44 (38.3%)
1.0-2.99	23 (20.0%)
≥3	16 (13.9%)
Serum creatinine (mg/dL)	1.00 (0.79-1.36)
eGFR (mL/min·1.73 m^2)^a	93.31 (70.90-123.10)
CKD stages^b, (%)
1	63 (54.8)
2	31 (27.0)
3a	12 (10.4)
3b	6 (5.2)
4	2 (1.7)
5	1 (0.9)

Data are presented as median (interquartile range) or frequency in percentage. ^aeGFR was calculated according to the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation [20]. ^bCKD stages 1–5 were divided by (G1), 60–89 (G2), 45–59 (G3a), 30–44 (G3b), 15–29 (G4), and <15 (G5) mL/min/1.73 m², respectively, according to the new KDIGO (Kidney Disease: Improving Global Outcomes) classification [23].