Table 1.
Comparison of levels and subclass distribution of anti-ADAMTS13 IgG antibodies between the first acute episode and relapse.
| First episode | Relapse | ||
|---|---|---|---|
| Clinical data | |||
| Number of individuals | 57 | 15 | |
| Age (years) | 41 (29–54) | 35 (28–44) | |
| Gender (female/male) | 42/15 | 12/3 | |
| Current episode No | 1 | 3 (2–5) | |
| Months since diagnosis of thrombotic thrombocytopenic purpura | 0 | 69 (46–230) | |
| Total anti-ADAMTS13 IgG concentration (U/mL) | |||
| IgG | 77.5 (47.6–161.8) | 42.3 (28.0–81.9) | p = 0.0831 |
| Proportion of IgG subclasses (%) | |||
| IgG1 | 42.0 (30.6–68.8) | 24.3 (21.0–28.8) | p = 0.0002 |
| IgG2 | 0.0 (0.0–2.6) | 1.1 (0.0–2.8) | p = 0.2230 |
| IgG3 | 2.2 (0.0–9.7) | 0.0 (0.0–0.2) | p = 0.0086 |
| IgG4 | 49.7 (14.0–68.3) | 73.6 (65.0–78.4) | p = 0.0004 |
| Concentration of IgG subclasses (U/mL) | |||
| IgG1 | 35.7 (17.5–96.6) | 12.8 (6.0–19.9) | p = 0.0066 |
| IgG2 | 0.0 (0.0–2.8) | 1.2 (0.0–3.8) | p = 0.1826 |
| IgG3 | 1.6 (0.0–8.2) | 0.0 (0.0–0.1) | p = 0.0061 |
| IgG4 | 25.2 (8.6–62.6) | 28.5 (21.7–59.7) | p = 0.1552 |
| Dominant subclasses (number of patients, %) | |||
| IgG1 | 27 (47.4%) | 0 (0%) | p = 0.0005 |
| IgG4 | 30 (52.6%) | 15 (100%) | |
Results of independent samples are shown; patients having samples in both disease stages were excluded from the analysis in order to allow statistic comparison of the independent groups. (Similar results are obtained if all results are involved.) Values are expressed as median (interquartile range). The subclass with the highest proportion was considered dominant. Significantly different values are shown in bold.