. 2017 Apr 27;8:476. doi: 10.3389/fimmu.2017.00476

Table 4.

Simple and stratified linear regression models to show the correlation of disease activity measurements and SIgA levels.

Models	Crude association (p value)	Stratified association (p value)
Models	Crude association (p value)	HLA-B27⁺	HLA-B27⁻	Symptoms time: ≤12 months	Symptoms time: >12 months
BASDAI vs. SIgA	−0.12 (0.005)^†	−0.14 (0.004)^†	−0.07 (0.34)	−0.07 (0.346)	−0.12 (0.01)^†
ASDAS-CRP vs. SIgA	−0.04 (0.014)^†	−0.055 (0.02)^†	−0.02 (0.36)	−0.04 (0.23)	−0.03 (0.13)
ASDAS-ESR vs. SIgA	−0.048 (0.002)^†	−0.053 (0.013)^†	−0.04 (0.099)	−0.03 (0.33)	−0.04 (0.006)^†

^†Statistical significance, p < 0.05.

ASDAS, Ankylosing Spondylitis Disease Activity Score; BASDAI, Bath Ankylosing Spondylitis Disease Activity Index; CRP, C-reactive protein; ESR, erythrocyte sedimentation rate; SIgA, secretory immunoglobulin A.