Pan-immune inflammation value as a biomarker in ankylosing spondilitis and associated with disease activity

Aims: Ankylosing spondylitis(AS) is the most common and characteristic form of Spondyloarthritis. The pan-immune inflammation value(PIV) is a marker obtained from complete blood count parameters, which has been used as an inflammatory and immune marker. In this study, we aimed to investigate the relationship between inflammation and disease activity in patients with AS and PIV. Methods: In this prospective controlled study a total of 208 participants were included, consisting of 104 AS patients and 104 healthy controls. Complete blood count values, including neutrophils, monocytes, lymphocytes, platelets, and also C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR), were measured in all participants. In AS group disease activity was assessed with Bath Ankylosing Spondylitis Disease Activity Index (BASDAI). The AS group was divided into two subgroups based on BASDAI score: low disease activity(BASDAI score <4) and high disease activity(BASDAI score ≥4).The pan-immune inflammation value of patients and the control group was calculated as neutrophil count × monocyte count × platelet count/lymphocyte count. Comparative analysis was performed between the two groups, and these values were also compared based on the BASDAI. Results: The AS group exhibited statistically higher values of CRP, monocytes, and PIV compared to the control group (p<0.001 for all). Patients with BASDAI≥4 had a statistically lower disease duration (p<0.001) and lymphocyte count (p:0.012) compared to those with BASDAI<4. Patients with BASDAI ≥ 4 had statistically higher values of CRP, ESR, neutrophils, platelets, and PIV compared to those with BASDAI<4 (p<0.001, p<0.001, p<0.001, p:0.008, p<0.001 respectively). Strong positive correlation was found between PIV and BASDAI (rho=0.790; p<0.001), moderate positive correlation with PIV and CRP (rho=0.467; p<0.001) and also positive correlation was found between PIV and ESR (rho=0.326; p<0.001). The specificity and sensitivity of PIV using a cutoff value of >309,2 were 80.0% and 86.0% respectively, for the active group. Conclusion: Since the parameters comprising PIV are obtained from a complete blood count, it provides an advantage for its use as a simple and cost-effective marker in ankylosing spondylitis patients. In our study, we demonstrated that PIV is sensitive and specific in differentiating disease activity in patients with ankylosing spondylitis from healthy individuals and associated with disease activity.