Table 2.
Characterization of the COL7 autoantibody response in EBA patients
| DIFa | Circ. | Variant | Ageb | Gender | MM-EBA | NON-MM EBA | ||||
|---|---|---|---|---|---|---|---|---|---|---|
| NON-MB | MB | ≤ median | > median | Female | Male | |||||
| IgA | 8.9% | 2.3% | 35.7%* | 6.9%* | 21.1% | 17.5% | 18.1% | 14.7% | 16.8%* | 7.2%* |
| IgE | 0.3% | 0.0% | 0.0% | 0.5% | 1.3% | 0.0% | 0.3% | 0.8% | 1.2%* | 0.0%* |
| IgG | 78.3% | 66.9% | 75,2% | 82.1% | 90.9% | 87.5% | 88.4% | 91.9% | 49.9% | 48.9% |
| IgM | 5.3% | 0.2% | 13.3% | 10.0% | 14.6% | 10.4% | 12.8% | 7.7% | 12.1%* | 3.7%* |
| C3 | 37.8% | N/A | 58.4% | 42.1% | 75.8% | 65.4% | 53.4% | 57.3% | 15.2% | 22.5% |
The numbers in the table correspond to the percentage of the respective Igs detected by direct IF microscopy (DIF) and circulating Ig (Circ.), detected by indirect IF microscopy, ELISA and/or Western blot analysis. Furthermore, the direct IF microscopy findings are also compared between NON-MB-EBA and MB-EBA, i.e., IgA is detected by direct IF microscopy in 24.7% of non-MB EBA patients, whereas IgA tissue deposits are only observed in 9.9% of MB EBA cases. Ig reactivity by direct IF microscopy is also assessed according to patient age (differentiated by the median age of the cohort) and gender as well as mucosal involvement. The lack of standardized diagnostics for EBA and missing details on which tests were performed, is a limitation of the table. Since, based on our experience, direct IF microscopy includes IgA, IgG and C3 in most laboratories, the data for these 3 parameters is most likely very valid
aAbbreviations: DIF direct immunofluorescent microscopy, Circ. circulating immunoglobulin, Variant EBA variant, Mucosal mucosal involvement
bMedian age: 50 years
*p < 0.05 (Chi square)