Table 3.
Comparison of the levels of antibodies (geometric means and 95% confidence intervals of enzyme-linked immunosorbent assay units) between individuals with no clinical attack and individuals with malaria attacks detected during the year of follow-up. These comparative analyses were carried out on log-transformed data using non-parametric Mann–Whitney U-tests.
| No attack | Attacks | P-value | |
|---|---|---|---|
| Age (years ± s.d. values) | 28·2 ± 1·8 | 13·3 ± 3·8 | 0·0006 |
| C231 | |||
| IgG | 4·28 (2·49–7·33) | 0·64 (0·20–2·05) | 0·004 |
| IgG1 | 0·701 (0·37–0·77) | 0·18 (0·08–0·38) | 0·013 |
| IgG2 | 1·09 (0·69–1·72) | 0·15 (0·07–0·32) | 0·0002 |
| IgG3 | 1·25 (0·79–2·00) | 0·17 (0·06–0·48) | 0·0004 |
| IgG4 | 0·150 (0·09–0·24) | 0·05 (0·02–0·11) | 0·0517 |
| IgM | 16·20 (11·99–21·88) | 7·87 (4·31–14·39) | 0·0419 |
| IgE | 0·144 (0·11–0·19) | 0·04 (0·02–0·09) | 0·0018 |
| Crude malaria antigen | |||
| IgG | 73·45 (62·52–86·10) | 35·64 (23·99–52·97) | 0·0009 |
| IgG1 | 131 .52 (89·95–191·87) | 27·48 (10·12–74·47) | 0·0023 |
| IgG2 | 1·47 (0·98–2·21) | 0·40 (0·16–0·98) | 0·0012 |
| IgG3 | 11·64 (9·51–14·26) | 2·69 (1·47–4·91) | 0·0001 |
| IgG4 | 0·32 (0·25–0·42) | 0·35 (0·24–0·52) | 0·631 |
| IgM | 11·07 (8·05–15·23) | 5·87 (2·78–12·42) | 0·121 |
| IgE | 0·22 (0·19–0·24) | 0·13 (0·09–0·19) | 0·0008 |
| EB200 | |||
| IgG | 0·373 (0·240–0·579) | 0·036 (0·011–0·124) | 0·0001 |
After Bonferroni adjustment for the range of hypotheses performed simultaneously, a P-value of less than 0·003 for each individual test ensures that the risk of declaring differences in antibody responses by chance is reduced (using this procedure, the overall chance of making such an unjustified claim for the entire family of tests remains at P = 0·05). The values for EB200 (OD values at 1/1000 dilution) were extracted from Ahlborg et al. [5]. Mean ages are given for each subgroup. s.d.: Standard deviation.