Autoantigen Profiling in Systemic Autoimmune Diseases

Example 8

In a second screening with 6088 antigens, the antigens which differentiate between healthy controls and donors with rheumatoid arthritis were tested on patients with early rheumatoid arthritis, SSc and SPA., This is of importance in particular since patients with collagenoses and mixed collagenoses have an overlapping autoantibody profile and therefore are difficult to diagnose, particularly in the early phase

FIG. 3 shows a volcano plot of the antigen reactivities of SLE patients against a combined group of patients with various autoimmune diseases, such as SSc, SPA, early rheumatoid arthritis, and SPA.

Following univariate statistical evaluation, a threshold value of p<0.05 and a 1.5 times modified reactivity compared with the control group were applied. A final list of antigen reactivities over both screens was established (Table 2).

In order to analyse the frequency of the newly identified antigens in comparison with, known antigens, a threshold value of 3 standard deviations (SD) above the mean value of the healthy samples was defined.

Astonishingly, at least 4 additional antigens were identified of which the frequency in SLE patients lies above 15%. These include TMPO (19%) (SEQ ID No. 13), HNRNPA1 (26%) (SEQ ID No. 5), XRCC5 (15%) (SEQ ID No. 22) and MVP (15%) (SEQ ID No. 7).

FIG. 4 shows the frequency of 23 antigens in comparison to the healthy controls.

Table 2 summarises the identified antigen reactivities and different group comparisons.