According the 'Scandinavian Journal of Rheumatology', the axial spondyloarthritis patients who reported a large symptom burden at baseline had poor response rates and low retention rate for TNFi.

Krabbe S and colleagues conducted nation wide DANBIO registry, observational cohort study to examine the effectiveness of TNFi treatment for axial spondyloarthritis (axSpA) patients with extremely poor patient-reported outcomes (PROs). The patients with axSpA who started first TNFi during the year 2011-2016 were divided as per the baseline Bath Ankylosing Spondylitis Disease Activity Index. The BASDAI > 9.0 to ≤ 10.0 was considered as poor BASDAI. Chi-squared tests were used to evaluate the treatment responses after six months in patients with extremely poor PROs were compared with other patients. Log-rank tests were used to examine the retention rates. The Bath Ankylosing Spondylitis Functional Index (BASFI), pain score and patient global score were used for similar analysis. 

Out of total 1396 patients with median age 39 years, 60% men participated in this study. The patients with extremely poor baseline BASDAI [63 patients (5%)] were often women, ever smokers, and human leucocyte antigen-B27 negative, and had higher BMI (body mass index). The response rates were poorer in patients with extremely poor BASDAI vs the rest of the patients. Lower 1-year treatment retention (51% and 68%) were seen in poor BASDAI patients. More, similar results were established for patients with extremely poor BASFI, pain score, and patient global score.  Also, the study didnot reviewed radiographs and MRI scans. It remains unresolved whether diagnostic difficulties or MRI inflammation and structural lesions affected the outcomes.