NSAIDs in axial spondyloarthritis: to be continued…?

Ankylosing spondylitis: From pathogenesis to therapy

Ankylosing spondylitis (AS) is an autoimmune rheumatic disease that primarily affects the axial joints, with its etiology complex and still not fully understood. The unknown pathogenesis of AS limits the development of treatment strategies, so keeping up-to-date with the current research on AS can help in searching for potential therapeutic targets. In addition to the classic HLA-B27 genetic susceptibility and Th17-related inflammatory signals, increasing research is focusing on the influence of autoantigen-centered autoimmune responses and bone stromal cells on the onset of AS. Autoantigens derived from gut microbiota and preferential TCR both exacerbate the autoimmune response in patients with AS. Furthermore, dysregulated bone metabolism also promotes pathological new bone formation in AS. Current treatments approved for AS almost focus on the management of inflammation with inconsistent treatment results due to the heterogeneity of patients. In this review, we systematically summarized various pathogenesis and management of AS, meanwhile discussed the underlying risk factors and potential therapeutic targets.

Pain Medication and Corticosteroid Use in Ankylosing Spondylitis, Psoriatic Arthritis, and Rheumatoid Arthritis in the United States: A Retrospective Observational Study

Objective

We compared pain medication use in patients with ankylosing spondylitis (AS), psoriatic arthritis (PsA), and rheumatoid arthritis (RA) versus matched control over 2 years; a subgroup analysis assessed changes in pain medication use in patients who initiated a biologic during 12 months before and after.

Methods

This was a retrospective observational cohort study using an administrative claims database. Newly diagnosed adult patients with AS, PsA, or RA identified between 1/1/2014 and 7/31/2017 were included. Demographics, baseline characteristics, and pain medication use were described using descriptive statistics. Differences in pain medication use were assessed using McNemar's/Wilcoxon signed-rank test for categorical/continuous variables.

Results

The study included 2180 AS, 5681 PsA, and 34,047 RA patients to assess overall pain medication use over 2 years; 188 AS, 921 PsA, and 1599 RA patients were included to assess changes in pain medication use 12 months before and after initiation of biologic. Demographics and baseline characteristics were balanced. In the overall cohort, 74.6% AS, 75.0% PsA, and 83.0% RA patients used any pain medication at baseline versus matched control; pain medications use 2 years after diagnosis date was reported in 73.5% AS, 74.1% PsA, and 81.3% RA patients. Among AS, PsA, and RA patients, use of prescribed NSAIDs (AS: 68.1 vs. 51.1%; PsA: 51.1 vs. 42.5%; RA: 61.1 vs. 41.5%; P < 0.05), glucocorticoids (AS: 56.4 vs. 41.5%; PsA: 57.4 vs. 46.9%; RA: 88.2 vs. 75.3%; P < 0.05), and opioids (AS: 42.6 vs. 36.2% [non-significant]; PsA: 38.1 vs. 33.8%; RA: 52.0 vs. 40.4%; P < 0.05) significantly decreased 12 months after biologic initiation versus prior.

Conclusions

Use of NSAIDs, glucocorticoids, and opioids are common among patients with AS, PsA, or RA, although the reported use of these co-medications after biologic initiation significantly decreases in the first year of treatment.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40744-021-00344-6.

Mechanisms and Mediators of Pain in Chronic Inflammatory Arthritis

Purpose of the review

Pain in chronic inflammatory joint diseases is a common symptom reported by patients. Pain becomes of absolute clinical relevance especially when it becomes chronic, i.e., when it persists beyond normal healing times. As an operational definition, pain is defined chronic when it lasts for more than 3 months. This article aims to provide a review of the main mechanisms underlying pain in patients with chronic inflammatory joint diseases, discussing in particular their overlap.

Recent findings

While it may be intuitive how synovial inflammation or enthesitis are responsible for nociceptive pain, in clinical practice, it is common to find patients who continue to complain of symptoms despite optimal control of inflammation. In this kind of patients at the genesis of pain, there may be neuropathic or nociplastic mechanisms.

Summary

In the context of chronic inflammatory joint diseases, multiple mechanisms generally coexist behind chronic pain. It is the rheumatologist’s task to identify the mechanisms of pain that go beyond the nociceptive mechanisms, to adopt appropriate therapeutic strategies, including avoiding overtreatment of patients with immunosuppressive drugs. In this sense, future research will have to be oriented to search for biomarkers of non-inflammatory pain in patients with chronic inflammatory joint diseases.

Ankylosing spondylitis disease activity score is related to NSAID use, especially in patients treated with TNF-α inhibitors

Background

Non-steroidal anti-inflammatory drugs (NSAIDs) are regarded as the cornerstone of conventional treatment for AS. However little is known about concomitant NSAID use during treatment (with TNF-α inhibitors) in daily clinical practice.

Methods and findings

Consecutive patients from the GLAS cohort were included. NSAID use and ASAS-NSAID index were evaluated at group level and at individual patient level during 52 weeks of follow-up. Analyses were stratified for treatment regimen. Generalized estimating equations (GEE) was used to evaluate NSAID use in relation to assessments of disease activity over time. In patients starting TNF-α inhibitors (n = 254), 79% used NSAIDs at baseline and this proportion decreased significantly to 38% at 52 weeks. ASAS-NSAID index also decreased significantly from median 65 to 0. In patients on conventional treatment (n = 139), 74% used NSAIDs at baseline with median ASAS-NSAID index of 50 and this remained stable during follow-up. At each follow-up visit, approximately half of the patients changed their type or dose of NSAIDs. GEE analysis over time showed that NSAID use was associated with AS disease activity score (p<0.05). This relation was more pronounced in patients treated with TNF-α inhibitors compared to conventional treatment (B = 0.825 vs. B = 0.250).

Conclusions

In this observational cohort of established AS patients, there was no difference in baseline NSAID use between patients with and without indication for TNF-α inhibitors. NSAID use decreased significantly after starting TNF-α inhibitors. During conventional treatment, NSAID use remained stable at group level. However, NSAID use changed frequently at individual patient level and was significantly associated with disease activity.

Pain in ankylosing spondylitis: a neuro-immune collaboration

Clinicians have commonly differentiated chronic back pain into two broad subsets: namely, non-inflammatory (or mechanical) back pain and inflammatory back pain. As the terminology suggests, the latter category, in which ankylosing spondylitis (AS) is prominent, presupposes a close link between pain and inflammation. Advances in research into the genetics and immunology of AS have improved our understanding of the inflammatory processes involved in this disease, and have led to the development of potent anti-inflammatory biologic therapeutic agents. However, evidence from clinical trials and from biomarker and imaging studies in patients with AS indicate that pain and inflammation are not always correlated. Thus, the assumption that pain in AS is a reliable surrogate marker for inflammation might be an over-simplification. This Review provides an overview of current concepts relating to neuro-immune interactions in AS and summarizes research that reveals an increasingly complex interplay between the activation of the immune system and pain pathways in the nervous system. The different types of pain experienced by patients with AS, insights from brain imaging studies, neurological mechanisms of pain, sex bias in pain and how the immune system can modify pain in patients with AS are also discussed.