The use of 30-50mer peptides for serology impairs sensitivity compared to the full length antigen, because peptides likely harbor less epitopes. We calculated the cumulative sensitivity of the 3 single peptide ELISAs and measured the experimental combination of the 3 peptides in one antigen mix (mixW). The cut-off of mixW was 0.352, which is in the same range as the cut-off of one of its components, namely longD12. By cumulating the individual results of the 3 assays, the theoretical sensitivity indeed increased from 57% to 70%, but specificity decreased to 82% (table 4) . Compared to cumulative positivity, pooling the 3 peptides in one well (mixW) led to a loss of positive test results. In return, the specificity increased due to a loss of cross-reactions. Positive test results obtained by single peptide ELISAs compared to pooled peptide ELISA are summarized in table 5.