Table 1.
Baseline clinical features and renal outcomes in family history-positive and -negative subgroups of IgA nephropathy
| Variables | Familial History of Renal Diseases | P value | |
|---|---|---|---|
| Negative | Positive | ||
| Number of Patients | n = 347 | n = 42 | |
| Clinical backgorund at renal biopsy | |||
| Age (yr) | 35 [15, 76] | 39 [19, 70] | 0.20 |
| Age onset of hematuria and/or proteinuria (yr) | 28 [5, 75] | 26 [10, 66] | 0.99 |
| Gender Male (n) | 171 (49.3) | 15 (35.7) | 0.10 |
| Female (n) | 176 (50.7) | 27 (64.3) | |
| eGFR (ml/min/1.73m2) | 74.00 [30.00, 153.00] | 69.50 [32.00, 115.20] | 0.048 |
| History of Hypertension (n) | 247 (71.2) | 24 (57.1) | 0.08 |
| History of Diabetes (n) | 17 (4.9) | 2 (4.8) | 1.00 |
| Mean arterial pressure (mmHg) | 85 [55, 141] | 88 [67, 107] | 0.46 |
| Urinalysis of RBC (per HPF) | 5 [1, 100] | 10 [1, 100] | 0.57 |
| Urinary protein excretion per day (gram) | 0.55 [0.00, 20.86] | 0.47 [0.00, 5.05] | 0.67 |
| Renal biopsy findings | |||
| C3 deposition in mesangium | 1 [0, 3] | 1 [0, 3] | 0.34 |
| C4 desposition in mesangium | 0 [0, 3] | 0 [0, 1] | 0.24 |
| IgA deposition in mesangium | 2 [1, 3] | 2 [1, 3] | 0.70 |
| IgG deposition along the capillary loops | 0 [0, 3] | 0 [0, 2] | 0.55 |
| Oxford MEST-C Score | |||
| M Score 1 (proportion, %) | 169 (48.7) | 21 (50.0) | 1.00 |
| E Score 1 (proportion, %) | 34 (9.8) | 6 (14.3) | 0.42 |
| S Score 1 (proportion, %) | 57 (16.4) | 5 (11.9) | 0.66 |
| T Score (0–2) by 1 increase | 0.27 (0.50) | 0.31 (0.47) | 0.66 |
| C score 1 to 0 (proportion, %) | 66 (19.0) | 6 (19.0) | 1.00 |
| GBM thickness (nm) | 293.3 [131,422] | 294.0 [159,455] | 0.93 |
| Number of patients with thin GBM(%) | 13 (3.7) | 2 (4.8) | 0.69 |
| Renal Outcomes | |||
| Age at last evaluation (yr) | 46.00 [18.00, 87.00] | 45.00 [24.00, 80.00] | 0.44 |
| Observational peroid (yr) | 9.00 [2.00, 25.00] | 8.00 [2.00, 25.00] | 0.47 |
| eGFR (ml/min/1.73 m2) | 66.00 [5.00, 160.50] | 54.00 [5.00, 106.50] | 0.02 |
| Mean eGFR reduction (ml/min/1.73m2/year) | −0.88 [−24.00, 10.23] | −1.09 [−13.20, 5.25] | 0.35 |
| More than 50% reduction of eGFR(proportion, %) | 41 (11.8) | 10 (23.8) | 0.048 |
| CKD stage 5 (proportion, %) | 27 (7.8) | 8 (19.0) | 0.04 |
| CKD stage 4 or 5 (proportion, %) | 42 (12.1) | 12 (28.6) | 0.01 |
| Primary outcome (proportion, %) | 41 (11.8) | 10 (23.8) | 0.048 |
| Therapy and intervension | |||
| Administration of immunosupressant (proportion %) | 6 (1.7) | 1 (2.4) | 0.55 |
| Adminstration of RAS inhibitors (%) | 218 (62.8) | 31 (73.8) | 0.18 |
| Tonsillectomy plus steroid-pulse therapy (%) | 171 (49.3) | 25 (59.5) | 0.25 |
| long-term oral prednisolone (%) | 35 (10.1) | 2 (4.8) | 0.40 |
A total 389 individuals for whom longitudinal progression data are available for more than 2 years (mean follow-up time 8.7 years) are studied. Values for categorial variables are given as number or (percentage) or [range]. MEST-C scores are determined according to the Oxford Classification [10]. Endocapillary hypercellularity: absent (E0) or present (E1); Segmental glomerulosclerosis absent (S0) or present (S1); Tubular atrophy/interstitial fibrosis #25% (T0), 26–50% (T1), or > 50% (T2); Cellular/fibro-cellular crescents absent (C0), present in at least one glomerulus (C1), in > 25% of glomeruli (C2). Mesangial depositions of IgA, C3, C4, as well as capillary IgG depositions are examined by immunofluorescence staining and are scored as four subclasses: 0 (absent), 1 (weak), 2 (Intermediate), and 3 (strong). Thickness of glomerular basement membrane is measured for several different segments along the capillaries on electron microscopy images and average thickness less than 200 nm is judged as thin glomerular basement membrane (TGBM)
The primary outcome consists of a hard endpoint (ESRD eGFR< 15 mL/min/1.73 m2) and a surrogate endpoint (50% or more reduction in renal function) [11]. eGFR, estimated glomerular filtration rate; FH, familial history; MAP, mean arterial pressure; RAS, renin angiotensin system. Quantitative variables are expressed as absolute number (mean with [range]), or frequency (%). Chi-square and t-tests are used for comparison. Results that have P < 0.05 are indicated in bold