Figure 1.

Human NK cell-specific open chromatin regions are enriched in AS genetic risk

(A) Calderon et al. study design. Peripheral blood cells from four healthy subjects were sorted into immune cell populations that we grouped in silico into seven cell types (see material and methods). Assay for transposase accessible chromatin using sequencing (ATAC-seq) was performed with and without prior in vitro activation.

(B) Graphical representation of LDSC-SEG analysis: identification of cell-type-specific annotations (in our case, open chromatin regions), followed by the integration with GWAS summary statistics to obtain a risk enrichment coefficient β and p value.

(C) Volcano plots showing results of differential accessibility analyses for each cell type compared to the other cell types. Colored dots indicate open chromatin peaks in the top decile of the t statistic for each cell type, which were used for LDSC-SEG analysis.

(D and E) Bar graphs displaying the AS genetic risk enrichment coefficient β and block jackknife SE for cell-type-specific open chromatin accounting for control peaks and baseline annotations. Summary statistics from the International Genetics of Ankylosing Spondylitis (IGAS) Consortium (D) and UK Biobank (E) GWASs were used.

∗p < 0.05.