Neuropathic pain in ankylosing spondylitis: a meta-analysis

Aim The aim of this study was to compare demographic characteristics, disease activity, functional status, and quality of life between ankylosing spondylitis (AS) with neuropatic pain (NP) and AS without NP (Non-NP). Methods The MEDLINE via PubMed, Cochrane, Scopus, and Embase database, from the earliest available date of indexing through December 20, 2018, were searched for comparative studies evaluating NP in AS patients. Two authors performed the data extraction independently. Any discrepancies were resolved by consensus. Results Four comparative studies were identified. There was no statistically significant difference in terms of age, body mass index, symptom duration, and inflammatory markers, such as erythrocyte sedimentation rate and C-reactive protein between NP and Non-NP. The sex ratios (F/M) were approximately 1/1 in NP and 1/2 in Non-NP and the proportion of human leukocyte antigen (HLA) B27-positive patients in NP and Non-NP was 65.7% and 83.0%, respectively. NP patients had significantly higher visual analogue scale pain scores, higher Bath Ankylosing Spondylitis Disease Activity Index, higher Bath Ankylosing Spondylitis Functional Index, and lower SF-Item Short Form physical component scores compare to Non-NP patients. Conclusion The current meta-analysis showed that NP patients had significantly higher pain severity, higher disease activity and lower quality of life than Non-NP patients. The sex ratio (F/M) and proportion of HLA-B27 positive patients were different between the two groups. Further well-designed studies are needed to substantiate our results.