Macrophage activation syndrome (MAS) is a life-threatening complication of systemic juvenile idiopathic arthritis (sJIA) characterised by a vicious cycle of immune amplification that can culminate in ...overwhelming inflammation and multiorgan failure. The clinical features of MAS overlap with those of active sJIA, complicating early diagnosis and treatment. We evaluated adenosine deaminase 2 (ADA2), a protein of unknown function released principally by monocytes and macrophages, as a novel biomarker of MAS.
We established age-based normal ranges of peripheral blood ADA2 activity in 324 healthy children and adults. We compared these ranges with 173 children with inflammatory and immune-mediated diseases, including systemic and non-systemic JIA, Kawasaki disease, paediatric systemic lupus erythematosus and juvenile dermatomyositis.
ADA2 elevation beyond the upper limit of normal in children was largely restricted to sJIA with concomitant MAS, a finding confirmed in a validation cohort of sJIA patients with inactive disease, active sJIA without MAS or sJIA with MAS. ADA2 activity strongly correlated with MAS biomarkers including ferritin, interleukin (IL)-18 and the interferon (IFN)-γ-inducible chemokine CXCL9 but displayed minimal association with the inflammatory markers C reactive protein and erythrocyte sedimentation rate. Correspondingly, ADA2 paralleled disease activity based on serial measurements in patients with recurrent MAS episodes. IL-18 and IFN-γ elicited ADA2 production by peripheral blood mononuclear cells, and ADA2 was abundant in MAS haemophagocytes.
These findings collectively identify the utility of plasma ADA2 activity as a biomarker of MAS and lend further support to a pivotal role of macrophage activation in this condition.
IL-1β is a proinflammatory mediator with roles in innate and adaptive immunity. Here we show that IL-1β contributes to autoimmune arthritis by inducing osteoclastogenic capacity in Tregs. Using mice ...with joint inflammation arising through deficiency of the IL-1 receptor antagonist (Il1rn-/-), we observed that IL-1β blockade attenuated disease more effectively in early arthritis than in established arthritis, especially with respect to bone erosion. Protection was accompanied by a reduction in synovial CD4+Foxp3+ Tregs that displayed preserved suppressive capacity and aerobic metabolism but aberrant expression of RANKL and a striking capacity to drive RANKL-dependent osteoclast differentiation. Both Il1rn-/- Tregs and wild-type Tregs differentiated with IL-1β accelerated bone erosion upon adoptive transfer. Human Tregs exhibited analogous differentiation, and corresponding RANKLhiFoxp3+ T cells could be identified in rheumatoid arthritis synovial tissue. Together, these findings identify IL-1β-induced osteoclastogenic Tregs as a contributor to bone erosion in arthritis.
Rheumatoid arthritis is a systemic autoimmune disease, but disease flares typically affect only a subset of joints, distributed in a distinctive pattern for each patient. Pursuing this intriguing ...pattern, we show that arthritis recurrence is mediated by long-lived synovial resident memory T cells (TRM). In three murine models, CD8+ cells bearing TRM markers remain in previously inflamed joints during remission. These cells are bona fide TRM, exhibiting a failure to migrate between joints, preferential uptake of fatty acids, and long-term residency. Disease flares result from TRM activation by antigen, leading to CCL5-mediated recruitment of circulating effector cells. Correspondingly, TRM depletion ameliorates recurrence in a site-specific manner. Human rheumatoid arthritis joint tissues contain a comparable CD8+-predominant TRM population, which is most evident in late-stage leukocyte-poor synovium, exhibiting limited T cell receptor diversity and a pro-inflammatory transcriptomic signature. Together, these findings establish synovial TRM as a targetable mediator of disease chronicity in autoimmune arthritis.
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•Arthritic human and murine joints acquire CD8+ resident memory T cells (TRM)•TRM from rheumatoid joints display a restricted T cell receptor repertoire•Antigen-activated TRM recruit other immune cells to cause an arthritis flare•Depletion of synovial TRM blocks local disease recurrence
Rheumatoid arthritis is characterized by recurrent inflammation of some, but not all, joints. Chang et al. show that CD8+ tissue-resident memory T cells accumulate in previously inflamed joints, nucleating local disease recurrence when triggered by antigens. TRM depletion attenuates arthritis flares, defining a mechanistic basis for joint-specific memory.
The aim of the study is to assess the relationship between childhood sexual abuse, obesity, and vulvodynia among adult women participating in a population-based longitudinal vulvodynia study.
Surveys ...assessed health status, diagnoses, risk factors, and screening test outcomes for women with vulvodynia. Associations between childhood sexual abuse (CSA) and obesity, CSA and vulvodynia, and obesity and vulvodynia were investigated. A multivariate model was used to determine if obesity mediates and/or modifies the relationship between CSA and vulvodynia.
Of 2,277 women participating in the study, 1,647 completed survey data on CSA at 18 months, body mass index at 24 months, and vulvodynia over the first 54 months of the survey. Mean age was 50.9 ± 15.8 years. Overall, race and ethnicity were 77.4% White, 15.7% Black, 2.4% Hispanic, and 4.5% other. Five hundred thirty-nine participants (32.7%) were obese (body mass index >30) and 468 (28.4%) were overweight. Physical CSA before age of 18 years was reported by 20.0% ( n = 329). During the study, 22.0% ( n = 362) screened positive for vulvodynia on one or more surveys. After controlling for demographic variables, both obesity and screening positive for vulvodynia were associated with a history of CSA before age of 18 years ( p = .013 and p < .001, respectively), but obesity was not associated with screening positive for vulvodynia ( p = .865). In addition, multivariate analysis indicated no mediation of the CSA/vulvodynia relationship by obesity.
Although obesity and vulvodynia were independently associated with a history of CSA, obesity did not mediate or modify the relationship between CSA and vulvodynia in adulthood.
Introduction
We investigated whether rheumatoid arthritis (RA)-related autoantibodies were associated with abnormalities on pulmonary function tests (PFTs).
Methods
We studied RA serostatus and PFT ...abnormalities within a RA registry. RA serostatus was assessed by research assays for cyclic citrullinated peptide (CCP) and rheumatoid factor (RF). Outcomes were abnormalities on clinically indicated PFTs, including restriction, obstruction, and diffusion abnormality. Logistic regression was used to obtain ORs and 95% CIs for the PFT abnormalities by RA serologic phenotypes independent of lifestyle and RA characteristics.
Results
Among 1272 analyzed subjects, mean age was 56.3 years (SD 14.1), 82.2% were female, and 69.5% were seropositive. There were 100 subjects with abnormal PFTs. Compared with seronegativity, seropositivity was associated with increased odds of any PFT abnormality (multivariable OR 2.29, 95% CI 1.30–4.03). When analyzing type of PFT abnormality, seropositivity was also associated with restriction, obstruction, and diffusion abnormalities; multivariable ORs were 2.48 (95% CI 1.26–4.87), 3.12 (95% CI 1.28–7.61), and 2.30 (95% CI 1.09–4.83), respectively. When analyzing by CCP and RF status, the associations were stronger for RF+ than for CCP+ (any PFT abnormality OR 1.99, 95% CI 1.21–3.27 for RF+ vs. RF−; OR 1.67, 95% CI 1.03–2.69 for CCP+ vs. CCP−) with a dose effect of higher RF titer increasing odds for each PFT abnormality (
p
for trend < 0.05).
Conclusions
Seropositive RA patients had two-fold increased risk for abnormalities on PFTs performed for clinical indications compared with seronegative RA. Patients with seropositive RA, particularly those with high-titer RF positivity, may be more likely to have obstructive and restrictive abnormalities, independent of smoking.
Key points
• Due to the known excess pulmonary morbidity/mortality in RA, we studied the relationship of rheumatoid arthritis (RA)-related autoantibodies with pulmonary function test (PFT) abnormalities using a large RA registry.
• We evaluated whether presence and levels of cyclic citrullinated peptide (CCP) and rheumatoid factor (RF) were associated with restriction, obstruction, and diffusion abnormalities on PFTs among 1272 subjects with RA.
• Seropositivity was associated with two-fold increased risk for any PFT abnormality, independent of confounders including smoking. Higher titers of RF conferred greatest risk for all PFT outcomes: obstruction, restriction, and diffusion abnormality.
• These results provide evidence that patients with RA should be closely monitored for pulmonary involvement, particularly those with high-titer RF seropositivity.
Neutrophils are implicated in multiple homeostatic and pathological processes, but whether functional diversity requires discrete neutrophil subsets is not known. Here, we apply single-cell RNA ...sequencing to neutrophils from normal and inflamed mouse tissues. Whereas conventional clustering yields multiple alternative organizational structures, diffusion mapping plus RNA velocity discloses a single developmental spectrum, ordered chronologically. Termed here neutrotime, this spectrum extends from immature pre-neutrophils, largely in bone marrow, to mature neutrophils predominantly in blood and spleen. The sharpest increments in neutrotime occur during the transitions from pre-neutrophils to immature neutrophils and from mature marrow neutrophils to those in blood. Human neutrophils exhibit a similar transcriptomic pattern. Neutrophils migrating into inflamed mouse lung, peritoneum and joint maintain the core mature neutrotime signature together with new transcriptional activity that varies with site and stimulus. Together, these data identify a single developmental spectrum as the dominant organizational theme of neutrophil heterogeneity.
In nerve and muscle cells, the voltage-gated opening and closing of cation-selective ion channels is accompanied by the translocation of 12-14 elementary charges across the membrane's electric field. ...Although most of these charges are carried by residues in the S4 helix of the gating module of these channels, the precise nature of their physical movement is currently the topic of spirited debate. Broadly speaking, two classes of models have emerged: those that suggest that small-scale motions can account for the extensive charge displacement, and those that invoke a much larger physical movement. In the most recent incarnation of the latter type of model, which is based on structural and functional data from the archaebacterial K(+) channel KvAP, a "voltage-sensor paddle" comprising a helix-turn-helix of S3-S4 translocates approximately 20 A through the bilayer during the gating cycle (Jiang, Y., A. Lee, J. Chen, V. Ruta, M. Cadene, B.T. Chait, and R. MacKinnon. 2003. Nature. 423:33-41; Jiang, Y., V. Ruta, J. Chen, A. Lee, and R. MacKinnon. 2003. Nature. 423:42-48.; Ruta, V., J. Chen, and R. MacKinnon. 2005. Cell. 123:463-475). We used two methods to test for analogous motions in the Shaker K(+) channel, each examining the aqueous exposure of residues near S3. In the first, we employed a pore-blocking maleimide reagent (Blaustein, R.O., P.A. Cole, C. Williams, and C. Miller. 2000. Nat. Struct. Biol. 7:309-311) to probe for state-dependent changes in the chemical reactivity of substituted cysteines; in the second, we tested the state-dependent accessibility of a tethered biotin to external streptavidin (Qiu, X.Q., K.S. Jakes, A. Finkelstein, and S.L. Slatin. 1994. J. Biol. Chem. 269:7483-7488; Slatin, S.L., X.Q. Qiu, K.S. Jakes, and A. Finkelstein. 1994. Nature. 371:158-161). In both types of experiments, residues predicted to lie near the top of S3 did not exhibit any change in aqueous exposure during the gating cycle. This lack of state dependence argues against large-scale movements, either axially or radially, of Shaker's S3-S4 voltage-sensor paddle.
IL-1beta is a proinflammatory mediator with roles in innate and adaptive immunity. Here we show that IL-1beta contributes to autoimmune arthritis by inducing osteoclastogenic capacity in Tregs. Using ...mice with joint inflammation arising through deficiency of the IL-1 receptor antagonist (Il1rn.sup.-/-), we observed that IL-1beta blockade attenuated disease more effectively in early arthritis than in established arthritis, especially with respect to bone erosion. Protection was accompanied by a reduction in synovial CD4.sup.+Foxp3.sup.+ Tregs that displayed preserved suppressive capacity and aerobic metabolism but aberrant expression of RANKL and a striking capacity to drive RANKL-dependent osteoclast differentiation. Both Il1rn.sup.-/- Tregs and wild-type Tregs differentiated with IL-1beta accelerated bone erosion upon adoptive transfer. Human Tregs exhibited analogous differentiation, and corresponding RANKL.sup.hiFoxp3.sup.+ T cells could be identified in rheumatoid arthritis synovial tissue. Together, these findings identify IL-1beta-induced osteoclastogenic Tregs as a contributor to bone erosion in arthritis.
In nerve and muscle cells, the voltage-gated opening and closing of cation-selective ion channels is accompanied by the translocation of 12-14 elementary charges across the membrane's electric field. ...Although most of these charges are carried by residues in the S4 helix of the gating module of these channels, the precise nature of their physical movement is currently the topic of spirited debate. Broadly speaking, two classes of models have emerged: those that suggest that small-scale motions can account for the extensive charge displacement, and those that invoke a much larger physical movement. In the most recent incarnation of the latter type of model, which is based on structural and functional data from the archaebacterial K super(+) channel KvAP, a "voltage-sensor paddle" comprising a helix-turn-helix of S3-S4 translocates similar to 20 Aa through the bilayer during the gating cycle (Jiang, Y., A. Lee, J. Chen, V. Ruta, M. Cadene, B.T. Chait, and R. MacKinnon. 2003. NATURE: 423:33-41; Jiang, Y., V. Ruta, J. Chen, A. Lee, and R. MacKinnon. 2003. NATURE: 423:42-48.; Ruta, V., J. Chen, and R. MacKinnon. 2005. CELL: 123:463-475). We used two methods to test for analogous motions in the Shaker K super(+) channel, each examining the aqueous exposure of residues near S3. In the first, we employed a pore-blocking maleimide reagent (Blaustein, R.O., P.A. Cole, C. Williams, and C. Miller. 2000. Nat. Struct. Biol. 7:309-311) to probe for state-dependent changes in the chemical reactivity of substituted cysteines; in the second, we tested the state-dependent accessibility of a tethered biotin to external streptavidin (Qiu, X.Q., K.S. Jakes, A. Finkelstein, and S.L. Slatin. 1994. J. Biol. Chem. 269:7483-7488; Slatin, S.L., X.Q. Qiu, K.S. Jakes, and A. Finkelstein. 1994. NATURE: 371:158-161). In both types of experiments, residues predicted to lie near the top of S3 did not exhibit any change in aqueous exposure during the gating cycle. This lack of state dependence argues against large-scale movements, either axially or radially, of Shaker's S3-S4 voltage-sensor paddle.
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