Table 2.
Baseline characteristics of MG patients with kidney injury stratified by the status of kidney biopsy.
| Characteristic | Kidney biopsy (n = 101) | Without kidney biopsy (n = 681) | P |
|---|---|---|---|
| Male | 68 (67.3%) | 413 (60.6%) | 0.198 |
| Age (year) | 56.2 ± 12.0 | 62.9 ± 12.1 | <0.001 |
| Hypertension | 36 (35.6%) | 195 (28.6%) | 0.15 |
| Diabetes | 17 (16.8%) | 73 (10.7%) | 0.072 |
| Hepatitis B | 8 (7.9%) | 17 (2.5%) | 0.004 |
| Serum studies | |||
| Albumin (g/l) | 25.8 ± 8.4 | 30.5 ± 7.2 | <0.001 |
| Creatinine (μmo/l) | 167.1 ± 182.3 | 223.3 ± 330.0 | 0.012 |
| eGFR (ml/min per 1.73 m2) | 62.7 ± 33.5 | 57.9 ± 37.3 | 0.182 |
| eGFR <60 (ml/min per 1.73 m2) | 46 (45.5%) | 355 (52.1%) | 0.217 |
| κ/λ | 1.35 (0.72–2.12) | 1.83 (0.68–9.91) | <0.001 |
| Urinary studies | |||
| Urinary protein (g/d) | 4.94 (1.67–7.07) | 1.10 (0.33–3.27) | <0.001 |
| Proteinuria >1.5 g/d | 38 (77.6%) | 128 (43.1%) | <0.001 |
| Hematuria | 72 (71.3%) | 335 (53.9%) | 0.001 |
| κ/λ | 1.42 (0.49–2.68) | / | / |
| Clonal subtype | |||
| Ig isotype | |||
| IgA(+) | 18 (17.8%) | 194 (28.5%) | 0.024 |
| IgG(+) | 30 (29.7%) | 386 (56.7%) | <0.001 |
| IgM(+) | 10 (9.9%) | 68 (10.0%) | 0.979 |
| IgA/IgG/IgM(+) | 0 (0) | 14 (2.1%) | 0.146 |
| IgA&IgG&IgM(−) | 43 (42.6%) | 19 (2.8%) | <0.001 |
| Ig light chain | |||
| Kappa(+) | 26 (25.7%) | 295 (43.3%) | 0.001 |
| Lambda(+) | 59 (58.4%) | 274 (40.2%) | 0.001 |
| Kappa&Lambda(+) | 0 (0) | 12 (1.8%) | 0.179 |
| Kappa&Lambda(−) | 16 (15.8%) | 100 (14.7%) | 0.76 |
| Received BM biopsy | 60 (59.4%) | 201 (29.5%) | <0.001 |
Values for continuous variables are described as mean ± SD or median (IQR) depending on the distribution, and for categoric variables described as count (%).