Spectrum of Spondyloarthritis Among Chinese Populations

Rapid and Sustained Effect of Ixekizumab on Patient Global, Spinal Pain, Stiffness, and Fatigue in Chinese Patients with Radiographic Axial Spondyloarthritis

INTRODUCTION

Ixekizumab, an interleukin 17A (IL-17A) inhibitor, has demonstrated rapid and sustained improvement in the signs and symptoms in patients with active radiographic axial spondyloarthritis (r-axSpA) in global and Chinese populations. We studied the effect of ixekizumab on patient-reported outcomes (PROs) (including patient global, spinal pain, stiffness, and fatigue) and overall health-related quality of life (HRQoL) of ixekizumab in the phase 3 study in China.

METHODS

In this Chinese phase 3, randomized, double-blind, placebo-controlled study, patients with r-axSpA were randomized (1:1) to receive ixekizumab 80 mg every 4 weeks (IXEQ4W; starting dose 160 mg) or placebo for 16 weeks. At week 16, patients receiving placebo were switched to IXEQ4W, and those receiving IXEQ4W continued, until week 52. Data for patient global, spinal pain, spinal pain at night, stiffness, and fatigue were collected through week 52. Minimally clinical important differences (MCIDs) were determined for spinal pain and spinal pain at night. The subgroup analyses by baseline disease duration since diagnosis and baseline C-reactive protein (CRP) level were conducted post hoc.

RESULTS

Compared with placebo, patients treated with IXEQ4W reported significantly greater improvement with a rapid onset in changes from baseline of PROs (patient global, spinal pain, spinal pain at night, stiffness, and fatigue) through week 16. Improvements were maintained through week 52. A similar trend of improvement was also observed in MCID response in spinal pain and spinal pain at night. The improvement in overall HRQoL was supported by EQ-5D-5L assessment. Subgroup analyses demonstrated that IXEQ4W provided significantly greater efficacy at week 16 compared with placebo, irrespective of baseline disease duration or baseline CRP level.

CONCLUSION

IXEQ4W provided rapid and sustained improvement in clinically relevant PROs and overall HRQoL through 1-year treatment in Chinese patients with r-axSpA. Regardless of the baseline disease duration or baseline CRP level, consistent efficacy was observed.

TRIAL REGISTRATION

ClinicalTrials.gov identifier NCT04285229.

A Cost-Effective and Labor-Saving Method for Detecting Human Leukocyte Antigen B27 Status via Sequence-Encoded Fluorescence Amplification Assay

Identification of human leukocyte antigen B27 (HLA-B27) by flow cytometry (FCM) has been widely applied in clinical practice for auxiliary diagnosis of ankylosing spondylitis (AS). However, FCM requires freshly prepared samples and relies on expensive equipment, reagents, and an experienced operator. To provide a cheaper and more convenient method for HLA-B27 detection, we proposed a new method termed sequence-encoded fluorescence amplification assay (SEFA), which specially recognized sequences of HLA-B27 gene (HLA-B∗27) covering current common subtypes in a single closed tube. SEFA could detect as low as 10 pg (equal to 3 copies) genomic DNA per reaction and distinguish HLA-B∗27 from other HLA-B alleles with highly similar sequences. A total of 288 clinical samples were tested by SEFA, including 181 patients with AS and 107 healthy controls. Compared with the detection results from FCM, two controversial samples of patients with AS were obtained and further confirmed to be consistent with SEFA by Sanger sequencing, indicating that this method was more accurate than FCM. Moreover, SEFA could detect HLA-B27 status by using supernatant from crude extract of 10-μL blood without commercial reagents. Overall, SEFA has the potential to be an alternative for HLA-B27 identification with the advantage of convenience and low cost, especially suitable for early diagnosis of AS in areas with limited medical resources.

Uncommon P1 Anchor-featured Viral T Cell Epitope Preference within HLA-A*2601 and HLA-A*0101 Individuals

The individual HLA-related susceptibility to emerging viral diseases such as COVID-19 underscores the importance of understanding how HLA polymorphism influences peptide presentation and T cell recognition. Similar to HLA-A*0101, which is one of the earliest identified HLA alleles among the human population, HLA-A*2601 possesses a similar characteristic for the binding peptide and acts as a prevalent allomorph in HLA-I. In this study, we found that, compared with HLA-A*0101, HLA-A*2601 individuals exhibit distinctive features for the T cell responses to SARS-CoV-2 and influenza virus after infection and/or vaccination. The heterogeneous T cell responses can be attributed to the distinct preference of HLA-A*2601 and HLA-A*0101 to T cell epitope motifs with negative-charged residues at the P1 and P3 positions, respectively. Furthermore, we determined the crystal structures of the HLA-A*2601 complexed to four peptides derived from SARS-CoV-2 and human papillomavirus, with one structure of HLA-A*0101 for comparison. The shallow pocket C of HLA-A*2601 results in the promiscuous presentation of peptides with "switchable" bulged conformations because of the secondary anchor in the median portion. Notably, the hydrogen bond network formed between the negative-charged P1 anchors and the HLA-A*2601-specific residues lead to a "closed" conformation and solid placement for the P1 secondary anchor accommodation in pocket A. This insight sheds light on the intricate relationship between HLA I allelic allomorphs, peptide binding, and the immune response and provides valuable implications for understanding disease susceptibility and potential vaccine design.

Anemia and Low Body Mass Index in Axial Spondyloarthritis: Results from ChinaSpA, the Chinese Spondyloarthritis Registry

INTRODUCTION

Anemia and malnutrition are recognized indicators of suboptimal physical condition in chronic inflammatory diseases. This study aimed to examine the association between anemia, low body mass index (BMI), and clinical outcomes in axial spondyloarthritis (axSpA).

METHOD

This cross-sectional analysis utilized data from the multicenter ChinaSpA cohort. A total of 4146 participants with axSpA were categorized into four groups based on BMI and hemoglobin levels: those with both anemia and low BMI, those with anemia only, those with low BMI only, and those with neither condition. Logistic regression analyses were performed to analyze the association between anemia, low BMI, inflammation status, functional impairment, and disease activity.

RESULTS

Anemia was present in 13.94%, low BMI in 11.99%, and both conditions in 2.15% of axSpA participants. Those with both anemia and low BMI showed significantly higher levels of inflammation (hypersensitive C-reactive protein [hsCRP] 30.60 mg/L vs. 8.44 mg/L), functional impairment (Bath Ankylosing Spondylitis Functional Index [BASFI] 3.80 vs. 2.10), and disease activity (Bath Ankylosing Spondylitis Disease Activity Index [BASDAI] 4.52 ± 2.04 vs. 3.67 ± 2.21; Ankylosing Spondylitis Disease Activity Score calculated with C-reactive protein [ASDAS_CRP] 3.51 ± 1.10 vs. 2.62 ± 1.21) compared to those without these conditions. After adjusting for sex and age, significant associations were observed between elevated hsCRP levels and the presence of low BMI (odds ratio [OR] 1.44, 95% CI 1.17-1.78), anemia (OR 1.91, 95% CI 1.56-2.32), and their concurrent presence (OR 3.59, 95% CI 2.22-5.80). Similarly, increased BASFI was significantly associated with low BMI (OR 1.57, 95% CI 1.25-1.97), anemia (OR 1.47, 95% CI 1.19-1.80), and their combination (OR 3.11, 95% CI 2.02-4.78).

CONCLUSION

All-cause anemia and low BMI are prevalent complications in patients with axSpA, exhibiting a significant correlation with elevated inflammation status and functional impairment. The simultaneous occurrence of anemia and low BMI particularly exacerbates clinical outcomes, emphasizing the critical role of comprehensive nutritional assessment and management in the therapeutic strategy for axSpA.

Unraveling the connection: Uveitis prevalence and risk factors in psoriasis patients - a population-based study

The association between uveitis and spondyloarthropathy (SpA)-related conditions is well-established. However, evidence describing the link between uveitis and psoriasis, and psoriasis without concomitant SpA-related conditions is scarce and conflicting. This large-scale population-based study sought to describe the prevalence and features of uveitis among psoriasis patients in Israel as well as investigating the risk for uveitis in different subgroups of psoriasis patients compared to the general population. We conducted a retrospective study utilizing the electronic database of the Meuhedet Health Maintenance Organization. The study included all patients diagnosed with psoriasis between 2000 and 2020, each patient was matched with four controls based on age, sex, place of residence, and index date. Logistic regression models were employed to assess the association between psoriasis and uveitis while adjusting for the presence of SpA-related conditions. A total of 61 003 psoriasis patients and 244 012 matched controls were included. The prevalence of uveitis was 1.3% versus 1.1% respectively (OR  1.12; 95% CI 1.10-1.30; p < 0.001). When adjusting to psoriasis severity, concurrent SpA, and psoriasis treatment no significant association was found. The rates of uveitis among psoriasis patients with concurrent SpA-related conditions was 3.2% compared to 1.4% in controls without psoriasis or SpA (OR 2.38; 95% CI 2.00-2.83; p < 0.001), while in psoriasis patients without SpA, the rate of uveitis was 1.0% and was similar to controls. Although crude rates of uveitis were higher in patients with severe psoriasis compared to mild psoriasis (2.1% vs. 1.1%), after adjustment, no significant association compared to controls was found in either group. Our findings suggest that the positive association between psoriasis and uveitis is primarily mediated by the coexistence of other SpA-related conditions. These findings imply the presence of a shared pathogenetic mechanism and set the direction for a phenotypic-targeted screening strategy.

Interferon-alpha 1 expression indicates the disease activity and response of patients with ankylosing spondylitis to anti-TNF-α treatment

OBJECTIVES

This study aimed to investigate whether interferon-alpha 1 (IFNA1) is predictive of Ankylosing spondylitis (AS) progression and treatment response to Tumour necrosis factor inhibitors (TNFis).

METHODS

Data of 50 AS patients receiving TNFi for 24 weeks were retrospectively analysed. AS patients who reached the Assessment of Spondyloarthritis International Society 40 response at the W24 were classified as responders to TNFi treatment; otherwise, they were classified as nonresponders. Human fibroblast-like synoviocytes (HFLS) isolated from AS patients (AS-HFLS) were used for in vitro validation.

RESULTS

When the IFNA1 expression level was used to diagnose AS patients, an area under the curve of 0.895 was yielded (P < .001). Pearson correlation analysis showed negative correlations between IFNA1 expression, C-reactive protein (CRP) level, Bath AS Disease Activity Index scores, AS Disease Activity Score with CRP, and the production of inflammatory cytokines. An increased IFNA1 expression level was found to be associated with a better treatment response to TNFi. IFNA1 overexpression could protect HFLS against inflammatory response in the setting of AS.

CONCLUSIONS

Blood IFNA1 deficiency is correlated with inflammatory cytokine production and disease activity and is indicative of unsatisfied response to TNFi treatment in AS patients.

Predictive values of circulating miR-146a and miR-155 for disease activity and clinical response to TNF-α blocking therapy in patients with ankylosing spondylitis

OBJECTIVE

Ankylosing spondylitis is an insidiously progressive and debilitating form of arthritis involving the axial skeleton. MicroRNAs have been reported to act as candidate biomarkers for ankylosing spondylitis diagnosis and progression. The study aimed to assess the roles of circulating miR-146a and miR-155 in ankylosing spondylitis and their prediction to clinical response to TNF-α blocking therapy.

METHODS

The study included 62 ankylosing spondylitis patients who were given originator TNFi with a 6-month period. Responders to anti-TNF treatment were defined as those reaching the Assessment of SpondyloArthritis international Society 40 (ASAS40) response at the 6-month interval, and nonresponders were defined those not (n = 24).

RESULTS

The ankylosing spondylitis patients at M0 (before beginning TNFi treatment) had higher serum levels of miR-146a and miR-155 than the healthy controls (p < .0001). Lower serum levels of miR-146a and miR-155 were noted in the responders (n = 38) compared with the nonresponders (n = 24) at different time points after anti-TNF treatment (p < .0001). The serum levels of miR-146a and miR-155 alone or in combination used to predict treatment outcomes produced AUCs of 0.884, 0.902, and 0.936, respectively. We submitted the following variables: miR-146a and miR-155 levels, BASDAI, ASDASCRP, ESR (mm/h), and CRP (mg/L) into multivariate logistic regression analysis, and results showed that higher levels of miR-146a (OR: 13.75, 95%CI: 1.32 to 143.57, p = .029), miR-155 (OR: 5.74, 95% CI: 1.63 to 20.20, p = .006), and ESR (OR: 1.08, 95% CI: 1.01 to 1.15, p = .022) were independent baseline predictors of ASAS40 response at 6-month anti-TNF-a treatment.

CONCLUSION

These findings obtained from the study suggest that high serum levels of miR-146a and miR-155 could aid in prediction of poor treatment outcomes after TNF-α blocking therapy.

Ixekizumab for Active Radiographic Axial Spondyloarthritis in Chinese Patients: 16- and 52-Week Results from a Phase III, Randomized, Double-Blind, Placebo-Controlled Study

INTRODUCTION

Ixekizumab, an interleukin-17A inhibitor, was efficacious and well tolerated for the treatment of active radiographic axial spondyloarthritis (r-axSpA) in international clinical studies. This phase III study aimed to determine the efficacy and safety of ixekizumab for treating Chinese patients with active r-axSpA.

METHODS

Adults with active r-axSpA naïve to biologic disease-modifying antirheumatic drugs (bDMARDs), or with an inadequate response/intolerance to one tumor necrosis factor inhibitor, were randomized (1:1), double-blind, to receive ixekizumab 80 mg every 4 weeks (IXEQ4W; starting dose 160 mg), or placebo, for 16 weeks. Patients receiving placebo were then switched to IXEQ4W, and those receiving IXEQ4W continued, until week 52. The primary endpoint was the proportion of bDMARD-naïve patients achieving an Assessment of SpondyloArthritis International Society 40 (ASAS40) response at week 16.

RESULTS

In total, 147 patients were randomized to receive placebo (n = 73) or IXEQ4W (n = 74). At week 16, more bDMARD-naive patients achieved ASAS40 in the IXEQ4W group (n = 66; 40.9%) than the placebo group (n = 64, 7.8%; p < 0.001). In the overall study population, ASAS40 was also achieved by more patients in the IXEQ4W group (37.8%) than the placebo group (8.2%; p < 0.001) at week 16, with a significant difference observed as early as week 1. There were significant improvements in all key secondary endpoints at week 16 with IXEQ4W versus placebo. Efficacy was sustained at week 52 in patients who continued IXEQ4W and there were also clinical improvements from weeks 16 to 52 in patients switched to IXEQ4W. The safety profile of ixekizumab was consistent with that described previously. Infections and injection-site reactions were the most frequently reported events of special interest.

CONCLUSIONS

IXEQ4W was associated with rapid and significant improvements in the signs and symptoms of active r-axSpA in Chinese patients at week 16 that were sustained at week 52, with no new safety signals.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov identifier: NCT04285229.

HLA-B*27 and Ankylosing Spondylitis: 50 Years of Insights and Discoveries

PURPOSE OF REVIEW

To commemorate the 50th anniversary of the groundbreaking discovery of a remarkably strong association between HLA-B*27 and ankylosing spondylitis (AS).

RECENT FINDINGS

In addition to HLA-B*27, more than 116 other recognized genetic risk variants have been identified, while epigenetic factors largely remain unexplored in this context. Among patients with AS who carry the HLA-B*27 gene, clonally expanded CD8 + T cells can be found in their bloodstream and within inflamed tissues. Moreover, the α and β chain motifs of these T-cell receptors demonstrate a distinct affinity for certain self- and microbial-derived peptides, leading to an autoimmune response that ultimately results in the onset of the disease. These distinctive peptide-binding and presentation characteristics are a hallmark of the disease-associated HLA-B*27:05 subtype but are absent in HLA-B*27:09, a subtype not associated with the disease, differing by only a single amino acid. This discovery represents a significant advancement in unraveling the 50-year-old puzzle of how HLA-B*27 contributes to the development of AS. These findings will significantly accelerate the process of identifying peptides, both self- and microbial-derived, that instigate autoimmunity. This, in return, will pave the way for the development of more accurate and effective targeted treatments. Moreover, the discovery of improved biomarkers, in conjunction with the emerging technology of electric field molecular fingerprinting, has the potential to greatly bolster early diagnosis capabilities. A very recently published groundbreak paper underscores the remarkable effectiveness of targeting and eliminating disease-causing T cells in a HLA-B*27 patients with AS. This pivotal advancement not only signifies a paradigm shift but also bolsters the potential for preventing the disease in individuals carrying high-risk genetic variants.

Immune-mediated inflammatory diseases and leukocyte telomere length: A Mendelian randomization study

Objective: To elucidate the potential causality of leukocyte telomere length (LTL) with immune-mediated inflammatory diseases (IMIDs), we conducted a Mendelian randomization (MR) study. Methods: The genetically predicted causation between LTL and IMIDs was evaluated using a two-sample MR method. We analyzed 16 major IMIDs, which included systemic lupus erythematosus (SLE), inflammatory bowel disease (IBD), ulcerative colitis (UC), Crohn's disease (CD), ankylosing spondylitis (AS), sicca syndrome (SS), rheumatoid arthritis (RA), type 1 diabetes (T1D), primary sclerosing cholangitis (PSC), idiopathic pulmonary fibrosis (IPF), atopic dermatitis (AD), sarcoidosis, hypothyroidism, hyperthyroidism, psoriasis, and childhood asthma. The random-effects inverse-variance weighted (IVW) method was performed as the main analytical approach in MR. Various sensitivity analyses, including MR-Egger, MR robust adjusted profile score (MR-RAPS), weighted median, MR pleiotropy residual sum and outlier (MR-PRESSO) methods, weighted mode, radial plot, and radial regression, were used to guarantee the robustness of the results and detect horizontal pleiotropy. Cochran's Q value was calculated to check for heterogeneity, and the MR Steiger approach was used to test the causal direction. Results: The MR results indicated significant inverse associations of LTL with risks of psoriasis (OR: 0.77, 95% CI: 0.66-0.89, and p = 3.66 × 10^-4), SS (OR: 0.75, CI: 0.58-0.98, and p = 0.03), RA (OR: 0.77, 95% CI: 0.68-0.88, and p = 9.85 × 10^-5), hypothyroidism (OR: 0.84, 95% CI: 0.78-0.91, and p = 7,08 × 10^-6), hyperthyroidism (OR: 0.60, 95% CI: 0.44-0.83, and p = 1.90 × 10^-3), sarcoidosis (OR: 0.67, 95% CI: 0.54-0.83, and p = 2.60 × 10^-4), and IPF (OR: 0.41, 95% CI: 0.29-0.58, and p = 4.11 × 10^-7) in the FinnGen study. We observed that longer LTL was associated with an increased risk of AS susceptibility (OR: 1.51, 95% CI: 1.18-1.94, and p = 9.66 × 10^-4). The results of the IVW method showed no causal relationship between TL and SLE (OR: 0.92, 95% CI: 0.62-1.38, and p = 0.69) in the FinnGen study; however, a significantly positive correlation was shown between LTL and SLE in another larger GWAS (OR: 1.87, 95% CI: 1.37-2.54, and p = 8.01 × 10^-5). Conclusion: Our findings reveal that abnormal LTL has the potential to increase the risk of IMIDs. Therefore, it could be treated as a predictor and may provide new potential treatment targets for IMIDs. However, the change of LTL may not be the direct cause of IMIDs. Further studies should aim at the pathogenic mechanism or potential protective effects of LTL in IMIDs.