Background: literature suggests that smoking is one of the crucial triggering factors of rheumatological diseases. (1) In axial Spondyloarthritis (axSpA), classified into radiographic SpA (AS) and non-radiographic SpA (nrSpA), smoking associated with disease activity and extra-articular manifestation. (2) The relationship between smoking and HLAB-27 as well as MRI inflammation in axSpA patients and the difference between nrSpA and AS regarding smoking have not been studied to date in details.
Objective: to investigate the influence of smoking on disease activity and MRI inflammation in axSpA patients (AS and nrSpA).
Methods: sixty Egyptian patients (42 males and 18 females) with the mean age (31.33 ± 7.02), with early active axial spondyloarthritis (49 AS and 11 non-radiographic SpA) within two years disease duration, diagnosed based on ASAS classification criteria. All clinical indices (BASDI, BASFI, BASMI, ASDAS-CRP) were applied to all patients. HLA-B27 and the inflammatory markers (ESR, CRP) was done. MRI of sacroiliac joints was performed in a standard protocol using short tau inversion recovery and T1 sequences (slice thickness 3-4mm, both semi-coronal and semi-axial orientations), and scored by the Berlin method. Smoking use assessed by smoking pack-year index.
Results: of all 60 patients, 38 smokers and 22 non-smokers. No significant difference regarding smoking packs index between nrSpA and AS. (p=0.822) There was a robust correlation between smoking packing index and the Berlin score of MRI in all axSpA patients (rs=0.631) (p=<0.001). Moreover, there was a significant correlation between smoking and C-reactive protein (rs=0.952) as well as HLA-B27. (rs=0.340) (p<0.001) Furthermore, a significant relationship between smoking and activity indices (BASDI (rs=0.961) and ASDAS-CRP (rs=0.938)). Otherwise, no significant correlation among smoking, BASMI, and BASFI as well as ESR.
Conclusion: Smoking has a significant association with HLA-B27, the inflammatory lesions of MRI, and clinical indices in early axial SpA patients