Table 1.
Presenting characteristics of subjects with biopsy-proven TMA
| All subjects | No underlying causes | |||||
|---|---|---|---|---|---|---|
| Columns | (1) | (2) | (3) | (4) | (5) | (6) |
| Subgroups | Total | ↓ PLT | N PLT | Total | ↓ PLT | N PLT |
| n subjects | 50 | 28 | 22 | 23 | 13 | 10 |
| Age (y) | 46 ± 17 | 47 ± 18 | 44 ± 16 | 47 ± 19 | 46 ± 21 | 47 ± 16 |
| Males (%) | 30 | 32 | 27 | 39 | 38 | 40 |
| No underlying causes (%) | 46 | 46 | 45 | 100 | 100 | 100 |
| Underlying cause (%) | 54 | 54 | 55 | 0 | 0 | 0 |
| Low Hb (%) | 94 | 100 | 86 | 96 | 100 | 90 |
| Mechanic haemolysis (%) | 94 | 100 | 86 | 96 | 100 | 90 |
| Low platelets (%) | 56 | 100 | 0§ | 56 | 100 | 0§ |
| Low Hb and PLT (%) | 56 | 100 | 0§ | 56 | 100 | 0§ |
| High LDH (%) | 86 | 89 | 82 | 87 | 92 | 80 |
| High creatinine (%) | 90 | 93 | 86 | 100 | 100 | 100 |
| Dialysis (%) | 50 | 43 | 59 | 65 | 62 | 70 |
| Plasmapheresis (%) | 58 | 61 | 55 | 78 | 87 | 70 |
Potential underlying causes included stage IV lupus nephritis (12%), mixed connective tissue disease with or without polymyositis (14%), drugs (14%), cyclosporine (0%), neoplasias (6%), renal transplantation (4%) and pregnancy (4%). For this study serum creatinine >1.2 mg/dL, Hb <120 g/L (female) or <140 g/L (male), PLT <150 × 109/L and LDH >220 U/L were considered abnormal (low or elevated). Mechanic haemolysis was defined as follows: anaemia + low haptoglobin or high indirect bilirubin + negative Coomb's test. In all cases, INR was < 1.26 and in no cases, abnormal serum D-dimers or fibrinogen was found. Based on Fisher's exact tests, values indicated by the § sign were significantly different statistically (P < 0.03) between the ‘low PLT’ and ‘normal PLT’ groups.