Table 3.
Characteristics of patients with amyloidosis compared with other causes of monoclonal gammopathy of renal significance
| Characteristics | Amyloidosis-Related Monoclonal Gammopathy of Renal Significance Lesions, n=164 | Nonamyloidosis Monoclonal Gammopathy of Renal Significance Lesions, n=97 | P Value |
|---|---|---|---|
| Age, yr | 60 (53–67) | 54 (47–62) | <0.001 |
| Men, n (%) | 104 (63) | 58 (60) | 0.56 |
| Hypertension, n (%) | 62 (38) | 83 (86) | <0.001 |
| Diabetes mellitus, n (%) | 15 (9) | 23 (24) | 0.001 |
| CKD, n (%) | |||
| Stage 3 | 22 (13) | 32 (33) | <0.001 |
| Stage 4 | 20 (12) | 23 (24) | 0.02 |
| Stage 5 | 8 (5) | 18 (19) | <0.001 |
| Serum studies | |||
| Albumin, g/dl | 2.5 (2.1–3.0) | 3.2±0.7 | <0.001 |
| Albumin <3.0 g/dl, n (%) | 124 (76) | 35 (36) | <0.001 |
| Hemoglobin, g/dl | 13.0 (11.9–14.3) | 10.6 (8.6–12.1) | <0.001 |
| Creatinine, mg/dl | 1.5 (0.7–1.4) | 2.5 (1.2–3.0) | <0.001 |
| eGFR, ml/min per 1.73 m2 | 72 (45–97) | 41 (18–59) | <0.001 |
| Complement 3, mg/dl | 95 (74–113, 144/164) | 71±24 (91/97) | <0.001 |
| Complement 4, mg/dl | 28 (19–33, 140/164) | 19±10 (90/97) | <0.001 |
| Urinary studies | |||
| Urinary protein, g/d | 5.7 (3.4–7.2) | 3.9 (0.9–5.3) | <0.001 |
| Proteinuria ≥1.5 g/d, n (%) | 152 (93) | 60 (62) | <0.001 |
| Hematuria, n (%) | 50 (30) | 67 (69) | <0.001 |
| Nephrotic proteinuria ≥3.5 g/d, n (%) | 122 (74) | 40 (41) | <0.001 |
| Hematologic studies | |||
| Clonality | |||
| Monoclonal | 156 (95) | 91 (94) | Reference |
| Biclonal | 8 (5) | 6 (6) | 0.65 |
| κ-free light chain, mg/L | 193 (11–40, 51/164) | 143 (29–162, 52/97) | <0.001 |
| λ-free light chain, mg/L | 151 (34–135, 51/164) | 110 (20–92, 52/97) | 0.12 |
| Free light chain-κ/λ ratio | 25.4 (0.1–0.7, 51/164) | 6.8 (0.6–4.9, 52/97) | <0.001 |
| Abnormal free light chain ratio, n (%) | 39/51 (76) | 27/52 (52) | <0.001 |
| Received bone marrow biopsy | 144 (88) | 86 (89) | 0.84 |
| Plasma cell, % | 3.7 (1.0–5.1, 144/164) | 1.6 (0.5–2.0, 86/97) | <0.001 |
| Plasma cell ≥10%, n (%) | 8/144 (6) | 0/86 (0) | 0.03 |
| Abnormal bone marrow biopsy specimen, n (%) | 75/82 (91) | 46/64 (72) | 0.002 |
Values for continuous variables are described as mean ± SD or median (interquartile range) depending on the distribution, and for categoric variables, they are described as count (percentage).