Figure 5.

Endoplasmic reticulum aminopepidase 1 (ERAP1) protein levels in patient and control samples. (a) Both immature (T₀) and mature (T₇₂) dendritic cells (DC) were analysed for ERAP1 expression. Sample concentrations were corrected using β-actin. Immature DC are represented in white and mature DC in black. Non-B27 healthy controls (C5, 9, 10, 16, 17, 19, 20, 21, 26, 28, 33, 40, 44, 46, 48, 50, 61, 63, 64, 65, 66, 68, 69, 70, 71, 74, 75, 78, 79); B27-positive healthy controls (C2, 4, 80, 87) and patient samples (P1, 2, 3, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 26, 27, 28, 29, 30). Where standard deviations are included, n > 3. (b) Mature DC samples were ranked according to ERAP1 protein expression levels; n = 28 in non-B27 control group and n = 25 in AS patient group. Means are shown as horizontal lines. P-value of 0·01 was calculated using Mann–Whitney U-test. The B27-positive control group were not included in these analyses because of the small size of the cohort.