Current aspects for the treatment of axial spondyloarthritis

Exploring physical function and physical activity in axial spondyloarthritis: Beyond clinical remission or low disease activity

OBJECTIVES

To investigate the crucial roles of physical function (PF) and physical activity (PA) in axial spondyloarthritis (axSpA) patients, as well as their correlation with disease activity (DA), and to explore the influence of general characteristics among them.

METHODS

We enrolled axSpA patients from Xijing Hospital, spanning March 2022 to August 2022. Spearman rank correlation coefficients were used to assess correlations between PA (measured by the Global Physical Activity Questionnaire [GPAQ]), PF (measured by the Assessment of Spondyloarthritis international Society Health Index [ASAS-HI], the Short Form 36-Item Health Survey [SF-36], and the Bath Ankylosing Spondylitis Functional Index [BASFI]), DA, and their influencing factors. A Mann-Whitney U-test and Kruskal-Wallis H-test were used to compare variables between different patients grouped by sex, human leukocyte antigen B27 (HLA-B27), hip involvement, and intensity of PA and DA.

RESULTS

Three hundred fifty-five axSpA patients were included. We observed a moderate to strong correlation between DA and PF in axSpA patients. PA was weakly correlated with DA or PF. DA varied significantly at different PA levels, and patients with low PA levels had poorer PF. Active patients had worse PF, less transport-related PA, and a higher rate of hip involvement with a worse Harris Hip Score (HHS).

CONCLUSIONS

We identified a close relationship between DA, PF, and PA in axSpA patients. Further, gender, HLA-B27, and hip involvement affected the clinical manifestation of axSpA patients. These findings demonstrate that clinical remission of axSpA patients requires a comprehensive assessment rather than a single remission of DA.

The study of the effect of HLA-B27 on THP-1 monocytic cells survival and its mechanism

OBJECTIVE

Previous studies have shown that human leukocyte antigen (HLA)-B27 induces the accumulation of unfolded proteins in the endoplasmic reticulum (ER) to cause ER stress, resulting in the unfold protein response (UPR), apoptosis and autophagy. However, it is still unknown whether it affects the survival of monocytes. In this study, we attempted to examine the effect of HLA-B27 gene knockout on the proliferation and apoptosis of THP-1 monocytic cell line and its potential mechanism.

METHODS

HLA-B27 gene knockout THP-1 cell line was constructed by lentivirus infection, and knockout efficiency was detected by immunofluorescence, quantitative reverse transcription - polymerase chain reaction (qRT-PCR) and western blot. Cell Counting Kit-8 (CCK-8) method and Annexin-V/PI double staining were used to detect the proliferation and apoptosis of the constructed THP-1 cell line, respectively. qRT-PCR was used to detect the effect of HLA-B27 inhibition on the expressions of ER molecular chaperone binding immunoglobulin protein (BiP) and genes about the UPR pathway. The proliferation rate of human BiP protein-stimulated THP-1 cells was detected by CCK-8 method.

RESULTS

HLA-B27 gene knockout THP-1 cells were successfully constructed by lentivirus infection. Knockout of HLA-B27 effectively promoted the proliferation of THP-1 cells and inhibited the apoptosis induced by cisplatin. qRT-PCR showed that BiP was synchronously increased, while activation of UPR pathway was inhibited. Stimulation with human BiP promoted the proliferation of THP-1 cells in a concentration-dependent manner.

CONCLUSIONS

HLA-B27 inhibition can promote the proliferation and inhibit the apoptosis of THP-1 cells. The inhibition function may be achieved through promotion of BiP and inhibition of UPR pathway activation.

Patient-tailored dose reduction of tumor necrosis factor inhibitors in axial spondyloarthritis

Tumor necrosis factor inhibitors have been widely used in the field of axial spondyloarthritis, with current guidelines now recommending dose reduction instead of withdrawal of biologics. Systemic review and meta-analyses in literature have summarized present tapering strategies and principles in published heterogeneous studies. In this study, we reviewed and provided an update on present evidence based on prospective and retrospective studies from 2008 to 2022 by performing a literature review of related publications on remission or relapse from PubMed. We further stated the core issues concerning dose reduction, including the timing, optimization, intensity, maintenance, monitoring, factors associated with tapering and solutions to de-escalation failure. Remission/relapse should be the principal consideration in dose reduction implementation for individuals without comorbidities. As a treat-to-target scope of this multifaceted systemic disease, extra-articular manifestations such as uveitis, psoriasis, inflammatory bowel disease, cardiovascular complication, hip involvement and progressed structural damage influence patient-tailored dose reduction plans. Safety concerns and costs should be integrated into the decision-making schedule to optimize the individualized dose reduction paradigm.