Should all patients with polymyalgia rheumatica have a vascular ultrasound assessment?

There is a growing appreciation that both giant cell arteritis (GCA) and polymyalgia rheumatica (PMR) are closely interrelated conditions that have significant overlap in aetiology, clinical characteristics and treatment regimens. Subclinical GCA in PMR is becoming increasingly recognised, and there is evolving evidence that this may be a more aggressive disease phenotype than PMR. Ultrasound (US) lends itself well as a screening tool for GCA in PMR; it is inexpensive, non-invasive, widely available, lacks ionising radiation, may be performed at the bedside and is recommended by EULAR as a first-line investigation for suspected GCA. There is insufficient evidence to currently recommend that all patients with PMR should have a US assessment for vascular involvement. However, as clinical and laboratory parameters alone do not accurately diagnose patients with subclinical GCA, we suggest that vascular US will be increasingly performed by rheumatologists in practice to identify these patients with PMR, preferably as part of larger prospective outcome studies.

Subclinical giant cell arteritis increases the risk of relapse in polymyalgia rheumatica.

OBJECTIVE: The aim of the present study was to determine the clinical significance of subclinical giant cell arteritis (GCA) in polymyalgia rheumatica (PMR) and ascertain its optimal treatment approach. METHODS: Patients with PMR who fulfilled the 2012 European Alliance of Associations for Rheumatology/American College of Rheumatology Provisional Classification Criteria for PMR, did not have GCA symptoms and were routinely followed up for 2 years and were stratified into two groups, according to their ultrasound results: isolated PMR and PMR with subclinical GCA. The outcomes (relapses, glucocorticoid use and disease-modifying antirheumatic drug treatments) between groups were compared. RESULTS: We included 150 patients with PMR (50 with subclinical GCA) with a median (IQR) follow-up of 22 (20-24) months. Overall, 47 patients (31.3 %) had a relapse, 31 (62%) in the subclinical GCA group and 16 (16%) in the isolated PMR group (p<0.001). Among patients with subclinical GCA, no differences were found in the mean (SD) prednisone starting dosage between relapsed and non-relapsed patients (32.4±15.6 vs 35.5±12.1 mg, respectively, p=0.722). Patients with subclinical GCA who relapsed had a faster prednisone dose tapering in the first 3 months compared with the non-relapsed patients, with a mean dose at the third month of 10.0±5.2 versus 15.2±7.9 mg daily (p<0.001). No differences were found between relapsing and non-relapsed patients with subclinical GCA regarding age, sex, C reactive protein and erythrocyte sedimentation rate. CONCLUSIONS: Patients with PMR and subclinical GCA had a significantly higher number of relapses during a 2-year follow-up than patients with isolated PMR. Lower starting doses and rapid glucocorticoid tapering in the first 3 months emerged as risk factors for relapse.

Temporal trends in COVID-19 outcomes in people with rheumatic diseases in Ireland: data from the COVID-19 Global Rheumatology Alliance registry.

OBJECTIVES: Although evidence is accumulating globally, data on outcomes in rheumatic disease and COVID-19 in Ireland are limited. We used data from the COVID-19 Global Rheumatology Alliance (C19-GRA) to describe time-varying COVID-19 outcomes for people with rheumatic disease in Ireland. METHODS: Data entered into the C19-GRA provider registry from Ireland between 24 March 2020 and 9 July 2021 were analysed. Differences in the likelihood of hospitalization and mortality according to demographic and clinical variables were investigated using Chi-squared test or Fisher's exact test, as appropriate. Trends in odds of hospitalization and mortality over time were investigated using logistic regression with the time period as a categorical variable. RESULTS: Of 212 cases included, 59.4% were female and median age was 58.0 years (range 13-96). Of the 212 cases, 92 (43%) were hospitalized and 22 (10.4%) died. Increasing age, a diagnosis of gout, ever smoking, glucocorticoid use, having comorbidities and specific comorbidities of cancer, cardiovascular and pulmonary disease were more common in those hospitalized. A diagnosis of inflammatory arthritis, csDMARD and/or b/tsDMARD use were less frequent in those hospitalized. Increasing age, a diagnosis of gout, ever smoking, having comorbidities and specific comorbidities of obesity, cardiovascular and pulmonary disease were more common in those who died. Odds of hospitalization or mortality did not change over time. CONCLUSION: No temporal trend was observed in either COVID-19-related hospitalization or mortality outcomes for people with rheumatic disease in Ireland.

Cross-phenotype association mapping of the MHC identifies genetic variants that differentiate psoriatic arthritis from psoriasis.

OBJECTIVES: Psoriatic arthritis (PsA) is a chronic inflammatory arthritis, with a strong heritable component, affecting patients with psoriasis. Here we attempt to identify genetic variants within the major histocompatibility complex (MHC) that differentiate patients with PsA from patients with cutaneous psoriasis alone (PsC). METHODS: 2808 patients with PsC, 1945 patients with PsA and 8920 population controls were genotyped. We imputed SNPs, amino acids and classical HLA alleles across the MHC and tested for association with PsA compared to population controls and the PsC patient group. In addition we investigated the impact of the age of disease onset on associations. RESULTS: HLA-C*06:02 was protective of PsA compared to PsC (p=9.57×10-66, OR 0.37). The HLA-C*06:02 risk allele was associated with a younger age of psoriasis onset in all patients (p=1.01×10-59). After controlling for the age of psoriasis onset no association of PsA to HLA-C*06:02 (p=0.07) was observed; instead, the most significant association was to amino acid at position 97 of HLA-B (p=1.54×10-9) where the presence of asparagine or serine residue increased PsA risk. Asparagine at position 97 of HLA-B defines the HLA-B*27 alleles. CONCLUSIONS: By controlling for the age of psoriasis onset, we show, for the first time, that HLA-C*06:02 is not associated with PsA and that amino acid position 97 of HLA-B differentiates PsA from PsC. This amino acid also represents the largest genetic effect for ankylosing spondylitis, thereby refining the genetic overlap of these two spondyloarthropathies. Correcting for bias has important implications for cross-phenotype genetic studies.

Outcomes of COVID-19 in people with rheumatic and musculoskeletal disease in Ireland over the first 2 years of the pandemic.

BACKGROUND: Poor COVID-19 outcomes occur with higher frequency in people with rheumatic and musculoskeletal diseases (RMD). Better understanding of the factors involved is crucial to informing patients and clinicians regarding risk mitigation. AIM: To describe COVID-19 outcomes for people with RMD in Ireland over the first 2 years of the pandemic. METHODS: Data entered into the C19-GRA provider registry from Ireland between 24th March 2020 and 31st March 2022 were analysed. Differences in the likelihood of hospitalisation and mortality according to demographic and clinical variables were investigated. RESULTS: Of 237 cases included, 59.9% were female, 95 (41.3%) were hospitalised, and 22 (9.3%) died. Hospitalisation was more common with increasing age, gout, smoking, long-term glucocorticoid use, comorbidities, and specific comorbidities of cardiovascular and pulmonary disease, and cancer. Hospitalisation was less frequent in people with inflammatory arthritis and conventional synthetic or biologic disease-modifying antirheumatic drug use. Hospitalisation had a U-shaped relationship with disease activity, being more common in both high disease activity and remission. Mortality was more common with increasing age, gout, smoking, long-term glucocorticoid use, comorbidities, and specific comorbidities of cardiovascular disease, pulmonary disease, and obesity. Inflammatory arthritis was less frequent in those who died. CONCLUSION: Hospitalisation or death were more frequently experienced by RMD patients with increasing age, certain comorbidities including potentially modifiable ones, and certain medications and diagnoses amongst other factors. These are important 'indicators' that can help risk-stratify and inform the management of RMD patients.

Predictors of hospitalization in patients with rheumatic disease and COVID-19 in Ireland: data from the COVID-19 global rheumatology alliance registry.

OBJECTIVES: Given the limited data regarding the risk of hospitalization in patients with rheumatic disease and coronavirus disease 2019 (COVID-19) in Ireland, we used the COVID-19 Global Rheumatology Alliance (GRA) registry data to study outcomes and their predictors. The primary objective was to explore potential predictors of hospitalization. METHODS: We examined data on patients and their disease-related characteristics entered in the COVID-19 GRA provider registry from Ireland (from 24 March 2020 to 31 August 2020). Multivariable logistic regression was used to assess the association of demographic and clinical characteristics with hospitalization. RESULTS: Of 105 patients, 47 (45.6%) were hospitalized and 10 (9.5%) died. Multivariable logistic regression analysis showed that age [odds ratio (OR) = 1.06, 95% CI 1.01, 1.10], number of co-morbidities (OR = 1.93, 95% CI 1.11, 3.35) and glucocorticoid use (OR = 15.01, 95% CI 1.77, 127.16) were significantly associated with hospitalization. A diagnosis of inflammatory arthritis was associated with lower odds of hospitalization (OR = 0.09, 95% CI 0.02, 0.32). CONCLUSION: Increasing age, co-morbidity burden and glucocorticoid use were associated with hospitalization, whereas a diagnosis of inflammatory arthritis was associated with lower odds of hospitalization.

Insulin-Resistant Pathways Are Associated With Disease Activity in Rheumatoid Arthritis and Are Subject to Disease Modification Through Metabolic Reprogramming: A Potential Novel Therapeutic Approach.

OBJECTIVE: To investigate a role for insulin-resistant pathways in inflammation and therapeutic targeting for disease modification in rheumatoid arthritis (RA). METHODS: RA disease activity and cardiovascular risk factors, including insulin resistance and body mass index (BMI), were assessed in an Irish RA cohort. Glucose transporter 1 (GLUT-1) and GLUT-4 activity in RA and osteoarthritis (OA) synovial tissue was examined using immunohistochemistry. Spontaneous release of proinflammatory mediators from ex vivo RA synovial explants and primary synovial fibroblast (SF) cell culture supernatants was quantified by enzyme-linked immunosorbent assay. Phosphorylated AMP-activated protein kinase (p-AMPK) and GLUT-1 protein expression was analyzed by Western blotting. Cellular glycolytic and oxidative phosphorylation was assessed using extracellular flux analysis. RESULTS: Insulin resistance was independently associated with both BMI (unstandardized coefficient B 0.113 [95% confidence interval (95% CI) 0.059-0.167]; P < 0.001) (n = 61) and swollen joint count in 28 joints (SJC28) (B 0.114 [95% CI 0.032-0.197]; P = 0.008) (n = 61). Increased GLUT-1 expression in RA synovium (n = 26) versus OA synovium (n = 16) was demonstrated (P = 0.0003), with increased expression in the lining, sublining, and vascular regions. In contrast, decreased GLUT-4 expression in the RA lining layer (n = 21) versus the OA lining layer (n = 8) was observed (P = 0.0358). Decreased GLUT-1 protein expression was observed in parallel with increased p-AMPK protein expression in SFs in the presence of metformin (n = 4). Metformin increased glycolytic activity and decreased oxidative phosphorylation in RASFs (n = 7) (P < 0.05 for both). Metformin or aminoimidazole carboxamide ribonucleotide presence decreased spontaneous production of interleukin-6 (IL-6), IL-8, and monocyte chemotactic protein 1 in RA synovial explants and SFs (n = 5-7). CONCLUSION: Insulin resistance is significantly associated with BMI and synovitis in RA, suggesting distinct interplay between glucose availability and inflammation in RA. Furthermore, the effect of metformin on proinflammatory mechanisms suggests a role for AMPK-modifying compounds in the treatment of RA.

Two gears of pumping by the sodium pump.

The kinetics of the phosphorylation and subsequent conformational change of Na(+),K(+)-ATPase was investigated via the stopped-flow technique using the fluorescent label RH421 (pH 7.4, 24 degrees C). The enzyme was preequilibrated in buffer containing 130 mM NaCl to stabilize the E1(Na(+))(3) state. On mixing with ATP in the presence of Mg(2+), a fluorescence increase occurred, due to enzyme conversion into the E2P state. The fluorescence change accelerated with increasing ATP concentration until a saturating limit in the hundreds of micromolar range. The amplitude of the fluorescence change (DeltaF/F(0)) increased to 0.98 at 50 microM ATP. DeltaF/F(0) then decreased to 0.82 at 500 microM. The decrease was attributed to an ATP-induced allosteric acceleration of the dephosphorylation reaction. The ATP concentration dependence of the time course and the amplitude of the fluorescence change could not be explained by either a one-site monomeric enzyme model or by a two-pool model. All of the data could be explained by an (alphabeta)(2) dimeric model, in which the enzyme cycles at a low rate with ATP hydrolysis by one alpha-subunit or at a high rate with ATP hydrolysis by both alpha-subunits. Thus, we propose a two-gear bicyclic model to replace the classical monomeric Albers-Post model for kidney Na(+),K(+)-ATPase.

Selecting an EMR in only eight years: one group's experience.

Why did it take a 27-physician multispecialty medical practice eight years to select and implement an electronic medical record (EMR) system? The author describes the difficult assessment process and emphasizes the importance of organizational readiness and financial wherewithal.

Evidence calcium pump binds magnesium before inorganic phosphate.

Calcium pump-catalyzed (18)O exchange between inorganic phosphate and water was studied to test the hypothesis that all P-type pumps bind Mg(2+) before P(i) and validate utilization of the rate equation for ordered binding to interpret differences between site-directed mutants and wild-type enzyme. The results were remarkably similar to those obtained earlier with sodium pump (Kasho, V. N., Stengelin, M., Smirnova, I. N., and Faller, L. D. (1997) Biochemistry 36, 8045- 8052). The equation for ordered binding of Mg(2+) before P(i) fit the data best with only a slight chance (0.6%) of P(i) binding to apoenzyme. Therefore, P(i) is the substrate, and Mg(2+) is an obligatory cofactor. The intrinsic Mg(2+) dissociation constant from metalloenzyme (K(M) = 3.5 +/- 0.3 mm) was experimentally indistinguishable from the sodium pump value. However, the half-maximal concentration for P(i) binding to metalloenzyme ((K(p)(')=6.3+/-0.6 mM)) was significantly higher ( approximately 6-fold), and the probability of calcium pump forming phosphoenzyme from bound P(i) (P(c) = 0.04 +/- 0.03) was significantly lower ( approximately 6-fold) than for the sodium pump. From estimates of the rate constants for phosphorylation and dephosphorylation, the calcium pump appears to catalyze phosphoryl group transfer less efficiently than the sodium pump. Ordered binding of Mg(2+) before P(i) implies that both calcium pump and sodium pump form a ternary enzyme.metal.phosphate complex, consistent with molecular structures of other haloacid dehalogenase superfamily members that were crystallized with Mg(2+) and phosphate, or a phosphate analogue, bound.

The role of loop 6/7 in folding and functional performance of Na,K-ATPase.

Alanine substitutions were made for 15 amino acids in the cytoplasmic loop between transmembrane helices 6 and 7 (L6/7) of the human alpha(1)-subunit of Na,K-ATPase. Most mutations reduced Na,K-ATPase activity by less than 50%; however, the mutations R834A, R837A, and R848A reduced Na,K-ATPase activity by 75, 89, and 66%, respectively. Steady-state phosphoenzyme formation from ATP was reduced in mutants R834A, R837A, and R848A, and R837A also had a faster E(2)P --> E(2) dephosphorylation rate compared with the wild-type enzyme. Effects of L6/7 mutations on the phosphorylation domain of the protein were also demonstrated by (18)O exchange, which showed that intrinsic rate constants for P(i) binding and/or reaction with the protein were altered. Although most L6/7 mutations had no effect on the interaction of Na(+) or K(+) with Na,K-ATPase, the E825A, E828A, R834A, and R837A mutations reduced the apparent affinity of the enzyme for both Na(+) and K(+) by 1.5-3-fold. 1-Bromo-2,4,6-tris(methylisothiouronium)benzene (Br-TITU(3+)), a competitive antagonist of Rb(+) and Na(+) occlusion, was used to test whether charged residues in L6/7 are involved in binding monovalent cations and cation antagonists. Br-TITU(3+) inhibited ouabain binding to wild type Na,K-ATPase with an IC(50) of 30 microM. Ouabain binding to the E825A, E828A, R834A, or R837A mutants was still inhibited by Br-TITU(3+), indicating that Br-TITU(3+) does not bind to charged residues in L6/7. This observation makes it unlikely that L6/7 functions as a cytoplasmic cation binding site in Na,K-ATPase, and together with the effects of L6/7 mutations on phosphate interactions with the enzyme suggests that L6/7 is important in stabilizing the phosphorylation domain and its relationship to the ion binding sites of the protein.

Nucleotide sequencing of psoriatic arthritis tissue before and during methotrexate administration reveals a complex inflammatory T cell infiltrate with very few clones exhibiting features that suggest they drive the inflammatory process by recognizing autoantigens.

Psoriatic arthritis is an interesting MHC class I allele associated autoimmune disease where injury is likely mediated exclusively by T cells. We used TCR beta-chain nucleotide sequencing to gain insight into the adaptive immune events responsible for this injury and determine whether the numerous oligoclonal expansions of this disease represent extreme determinant spreading among driving clones that recognize autoantigen or were non-Ag-driven, inflammation-related expansions. Because methotrexate suppresses but does not eliminate this inflammation, we hypothesized that clones persisting during methotrexate treatment would likely drive the inflammation. Seventy-six percent of the T cell clones in active tissue were polyclonal and unexpanded, accounting for 31% of transcripts. They were decreased greatly by methotrexate. Strikingly, most expanded clones in the inflamed joint did not persist during methotrexate treatment, were found only in inflammatory sites, exhibited no structural homology to one another, and were either CD4 or CD8 in lineage, suggesting they were non-autoantigen-driven, inflammation-related expansions. Only 12% of the expanded clones could be grouped into clonal sets distinguished by structurally homologous CDR3 beta-chain amino acid motifs suggesting Ag drive. These were exclusively CD8 in lineage, persisted during methotrexate administration, and were present in both joint fluid and blood implying they were candidate driver clones that recognized an autoantigen. However, a major set of putative driver clones exhibited a previously described EBV-specific beta-chain motif, emphasizing that the dominant feature of the disease was activation of multiple clones apparently lacking specificity for an inciting autoantigen.