Autoantibodies identify primary Sjögren's syndrome in patients lacking serum IgG specific for Ro/SS-A and La/SS-B.

OBJECTIVE: Identify autoantibodies in anti-Ro/SS-A negative primary Sjögren's syndrome (SS). METHODS: This is a proof-of-concept, case-control study of SS, healthy (HC) and other disease (OD) controls. A discovery dataset of plasma samples (n=30 SS, n=15 HC) was tested on human proteome arrays containing 19 500 proteins. A validation dataset of plasma and stimulated parotid saliva from additional SS cases (n=46 anti-Ro+, n=50 anti-Ro-), HC (n=42) and OD (n=54) was tested on custom arrays containing 74 proteins. For each protein, the mean+3 SD of the HC value defined the positivity threshold. Differences from HC were determined by Fisher's exact test and random forest machine learning using 2/3 of the validation dataset for training and 1/3 for testing. Applicability of the results was explored in an independent rheumatology practice cohort (n=38 Ro+, n=36 Ro-, n=10 HC). Relationships among antigens were explored using Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) interactome analysis. RESULTS: Ro+ SS parotid saliva contained autoantibodies binding to Ro60, Ro52, La/SS-B and muscarinic receptor 5. SS plasma contained 12 novel autoantibody specificities, 11 of which were detected in both the discovery and validation datasets. Binding to ≥1 of the novel antigens identified 54% of Ro- SS and 37% of Ro+ SS cases, with 100% specificity in both groups. Machine learning identified 30 novel specificities showing receiver operating characteristic area under the curve of 0.79 (95% CI 0.64 to 0.93) for identifying Ro- SS. Sera from Ro- cases of an independent cohort bound 17 of the non-canonical antigens. Antigenic targets in both Ro+ and Ro- SS were part of leukaemia cell, ubiquitin conjugation and antiviral defence pathways. CONCLUSION: We identified antigenic targets of the autoantibody response in SS that may be useful for identifying up to half of Ro seronegative SS cases.

The relationship between aerobic fitness and low-flow-mediated constriction in older adults.

PURPOSE: Aerobic fitness is directly related to favorable vasodilatory (i.e., flow-mediated dilation; FMD) and vasoconstrictor functions (i.e., low-flow-mediated constriction; L-FMC) in young adults. Furthermore, aerobically fit older adults (OA) have larger FMD responses than their less fit peers. However, the relationship between aerobic fitness and vasoconstrictor responsiveness is unknown in OA. We hypothesized that OA who are more aerobically fit will exhibit a greater L-FMC response than their less fit counterparts. METHODS: Forty-seven healthy OA (67 ± 5 years) were divided into less (LF; n = 27) and more aerobically fit (MF; n = 20) groups based on peak oxygen consumption (VO2peak). VO2peak was determined from an incremental maximal cycle ergometer test via indirect calorimetry. FMD and L-FMC were assessed in the brachial artery via high-resolution duplex ultrasonography. RESULTS: VO2peak (18.3 ± 3.2 versus 29.1 ± 5.8 ml/kg/min; P < 0.001) and L-FMC were both greatest in the MF versus LF groups (-1.2 ± 0.9 vs. - 0.5 ± 0.6%; P = 0.01). Furthermore, the MF group had an enhanced FMD response (5.6 ± 1.5 versus 3.9 ± 1.2%; P < 0.001). In the pooled sample, there was a negative correlation (r = - 0.52; P < 0.001) between VO2peak (22.9 ± 7.0 ml/kg/min) and L-FMC (-0.8 ± 0.8%). CONCLUSIONS: In an older population, greater aerobic fitness was associated with a more favorable vasoconstrictor response to low-flow conditions. Interventional or longitudinal aerobic exercise training studies are warranted in this population to determine the impact of training-induced increases in VO2peak on L-FMC.

Antibodies to Both Ro52 and Ro60 for Identifying Sjögren's Syndrome Patients Best Suited for Clinical Trials of Disease-Modifying Therapies.

OBJECTIVE: To assess anti-Ro52 and anti-Ro60 serologic profiles as markers of clinically relevant phenotypic subsets of patients with Sjögren's syndrome (SS). METHODS: From a cohort of 839 consecutive patients with suspected or established SS seen in our multidisciplinary SS center, we compared the association of key phenotypic features in 390 patients who fulfilled SS classification criteria and in the parent cohort, stratifed by the presence of both anti-Ro60 and anti-Ro52, anti-Ro60 alone, and anti-Ro52 alone. RESULTS: The SS cohort included 227 patients (58%) with both anti-Ro60 and anti-Ro52, 65 (17%) with anti-Ro60 alone, 58 (15%) with anti-Ro52 alone, and 40 (10%) with neither antibody. Those with both anti-Ro60 and anti-Ro52 had a significantly increased prevalence of abnormal ocular surface staining, focal lymphocytic sialadenitis with focus score ≥1, antinuclear antibody ≥1:320, anti-SSB/La, rheumatoid factor, and IgG ≥15.6 gm/liter (P < 0.0016 for all). The groups with isolated anti-Ro52 and anti-Ro60 were equivalent to each other in their phenotypic associations, except for rheumatoid factor, which was higher in the anti-Ro52 alone group. The associations of these Ro antibody serologic profiles were similar in the parent cohort, except for additional associations with salivary gland enlargement and parotid gland ultrasound score. CONCLUSION: SS patients with both anti-Ro60 and anti-Ro52 antibodies are distinguished by a higher prevalence of markers of B-cell hyperactivity and glandular inflammation. Antibody reactivity to both Ro60 and Ro52 may thus serve as an important inclusion criterion for SS patients in clinical trials where the therapeutic agent targets pathways mediating these pathogenic abnormalities.

Extraglandular ocular involvement and morbidity and mortality in primary Sjögren's Syndrome.

PURPOSE: To report the significance of extraglandular ocular involvement and long-term systemic morbidity and mortality in primary Sjögren's Syndrome (SS). METHODS: This retrospective, longitudinal cohort study included consecutive patients with primary SS evaluated at a tertiary referral center. An electronic chart review was performed and all available data were extracted from clinic visits between October 1999 and March 2019. The primary outcome measures included occurrence of extraglandular ocular manifestations of SS, serological markers, prevalence of malignancy, and incidence of death. RESULTS: One hundred and twenty-six SS patients with minimum 3 years of follow-up (median 9.6, range 3.0-15.9 years, total of 1,235 patient-years) were included. Of those, 10 patients with inflammatory keratolysis or scleritis had 2.3 times greater likelihood of death compared to the rest of the cohort (OR = 2.3, 95% confidence interval [CI] 0.5 to 4.0, p = 0.01) due to SS related complications. The lifetime prevalence of any malignancy in the entire cohort was 15.5%. The most common hematologic malignancy was non-Hodgkin's lymphoma (4.8%) and the most common solid malignancy was breast cancer (6.0%). Men SS patients were more likely to have a history of or concurrent malignancy compared to women (30.0% versus 13.7%, p = 0.16) and double the mortality (OR = 2.1, 95% CI 0.09 to 1.4, p = 0.04), independent of malignancy. CONCLUSIONS: SS patients with serious ocular manifestations, particularly men, may be at greater risk for mortality due to SS complications. The eye seems to be the barometer of systemic disease activity.

Impact of High-Intensity Interval Training, Moderate-Intensity Continuous Training, and Resistance Training on Endothelial Function in Older Adults.

PURPOSE: It is unclear if high-intensity interval training (HIIT) elicits superior improvements in brachial artery (BA) flow-mediated dilation (FMD) responses (i.e., endothelial-dependent vasodilation) than moderate-intensity continuous training (MICT) or resistance training (RT) in otherwise healthy older adults. Whether HIIT enhances lower-limb FMD responses and/or augments low flow-mediated constriction (L-FMC) (endothelial-dependent vasoconstriction) responses more than MICT or RT is also unknown. We tested the hypothesis that HIIT would improve BA and popliteal artery (POP) FMD and L-FMC responses more than MICT or RT in healthy older adults. METHODS: Thirty-eight older adults (age, 67 ± 6 yr) performed 6 wk of either HIIT (2 × 20 min bouts alternating between 15-s intervals at 100% of peak power output [PPO] and passive recovery [0% PPO]; n = 12), MICT (34 min at 60% PPO; n = 12), or whole-body RT (8 exercises, 2 × 10 repetitions; n = 14). The L-FMC and FMD were measured before and after training using high-resolution ultrasound and quantified as the percent change in baseline diameter during distal cuff occlusion and after cuff release, respectively. RESULTS: Resting BA blood flow and vascular conductance (both, P < 0.003) were greater after HIIT only. The HIIT and MICT similarly increased BA-FMD (pre-post: both, P < 0.001), but only HIIT improved BA L-FMC (P < 0.001). Both HIIT and MICT similarly enhanced POP FMD and L-FMC responses (both, P < 0.045). Resistance training did not impact FMD or L-FMC responses in either artery (all, P > 0.20). CONCLUSIONS: HIIT and MICT, but not RT, similarly improved lower-limb vasodilator and vasoconstrictor endothelial function in older adults. Although HIIT and MICT groups enhanced BA vasodilator function, only HIIT improved resting conductance and endothelial sensitivity to low-flow in the BA. In the short-term, HIIT may be most effective at improving peripheral vascular endothelial function in older adults.

Relationship between brachial and popliteal artery low-flow-mediated constriction in older adults: impact of aerobic fitness on vascular endothelial function.

We previously observed that brachial artery (BA) low-flow-mediated constriction (L-FMC) is inversely related to aerobic fitness (i.e., V̇o2peak) in older adults (OA). However, it is unclear if an L-FMC response is elicited in the popliteal artery (POP) or if a similar inverse relationship with aerobic fitness exists. Considering that the POP experiences larger shear stress fluctuations during sedentary behaviors and traditional lower limb modes of aerobic exercise, we tested the hypotheses that 1) heterogeneous L-FMC responses exist between the BA versus POP of OA, and 2) that aerobic fitness will be inversely related to POP L-FMC. L-FMC was assessed in 47 healthy OA (30 women, 67 ± 5 yr) using duplex ultrasonography and quantified as the percent decrease in diameter (from baseline) during the last 30 s of a 5-min distal cuff occlusion period. When allometrically scaled to baseline diameter, the BA exhibited a greater L-FMC response than the POP (-1.3 ± 1.6 vs. -0.4 ± 1.6%; P = 0.03). Furthermore, L-FMC responses in the BA and POP were not correlated (r = 0.22; P = 0.14). V̇o2peak was strongly correlated to POP L-FMC (r = -0.73; P < 0.001). The heterogeneous BA versus POP L-FMC data indicate that upper limb L-FMC responses do not represent a systemic measure of endothelial-dependent vasoconstrictor capacity in OA. The strong association between V̇o2peak and POP L-FMC suggests that localized shear stress patterns, perhaps induced by lower limb dominant modes of aerobic exercise, may result in greater vasoconstrictor responsiveness in healthy OA. NEW & NOTEWORTHY We compared low-flow-mediated constriction responses between the brachial and popliteal arteries of healthy older adults. Vasoconstrictor responses were not correlated between arteries. A strong relationship between aerobic fitness and low-flow-mediated vasoconstriction was observed in the popliteal artery. These findings suggest that brachial vasoconstrictor responsiveness is not reflective of the popliteal artery, which is exposed to larger shear stress fluctuations during bouts of sedentary behavior and traditional lower limb modes of exercise.

Short-term supplement of virgin coconut oil improves endothelial-dependent dilation but not exercise-mediated hyperemia in young adults.

Virgin coconut oil (VCO) is high in antioxidants, which reduce reactive oxygen species-induced conversion of vascular endothelial-derived nitric oxide (NO) to toxic peroxynitrite. As such, flow-mediated dilation (FMD, a surrogate marker of NO bioavailability) and exercise-mediated hyperemia may be enhanced following VCO treatment. Animal research supports these findings, but direct assessments of FMD after short-term VCO use in humans are unknown. We tested the hypotheses that a 4-week VCO supplement (30 mL·d-1) would improve popliteal artery (PA) FMD and the hyperemic response to aerobic exercise. Thirty-four young adults were divided into VCO (n = 19, 9 women, 22 ±â€¯2 years, 24 ±â€¯3 kg·m-2) and control (CON: n = 15, 7 women, 24 ±â€¯2 years, 24 ±â€¯3 kg·m-2) groups. PA-FMD and blood flow were assessed via high-resolution duplex ultrasonography (Vivid i, GE Healthcare, Mississauga, Ontario, Canada). PA blood flow was measured at rest and for 5 minutes following a 10-minute bout of moderate-intensity (60% heart rate reserve) cycling exercise. Total PA blood volume was calculated as the integral of the 5-minute postexercise PA blood flow response. After 4 weeks, PA-FMD increased (P = .04) following VCO supplementation (4.9% ±â€¯0.9% to 5.5% ±â€¯1.2%) with no change (P > .9) in the CON group (5.7% ±â€¯2.1% to 5.8% ±â€¯1.9%). There were no differences (both P > .28) in the postexercise total PA blood volume response in either group (VCO: 495 ±â€¯355 to 598 ±â€¯384 mL; CON: 562 ±â€¯362 to 488 ±â€¯229 mL). Short-term VCO supplementation does not alter aerobic exercise-mediated blood flow responses in young adults. However, the augmented popliteal FMD response observed in the VCO supplement group indicates that short-term VCO supplementation improves vascular endothelial function in young, healthy adults.

Achieving Canadian physical activity guidelines is associated with better vascular function independent of aerobic fitness and sedentary time in older adults.

Canadian physical activity guidelines recommend older adults accumulate 150 min of weekly moderate to vigorous physical activity (MVPA). Older adults who are insufficiently active may have reduced blood vessel health and an increased risk of cardiovascular disease. We tested this hypothesis in 11 older adults who did (7 female; age, 65 ± 5 years; MVPA, = 239 ± 81 min/week) and 10 older adults who did not (7 female; age, 68 ± 9 years; MVPA, 95 ± 33 min/week) meet MVPA guidelines. Flow-mediated dilation (FMD) in the brachial (BA) and popliteal (POP) arteries, as well as nitroglycerin-mediated dilation (NMD; endothelial-independent dilation) in the POP were assessed via ultrasonography. Aerobic fitness (peak oxygen uptake) was determined using a graded, maximal cycle ergometry test via indirect calorimetry. MVPA and sedentary time were assessed over 5 days using the PiezoRx and activPAL, respectively. There were no differences in peak oxygen uptake (26 ± 10 vs. 22 ± 10 mL O2/(kg·min); p = 0.26) or sedentary time (512 ± 64 vs. 517 ± 76 min/day; p = 0.87) between groups; however, those who achieved the MVPA guidelines had a higher BA-FMD (5.1% ± 1.3% vs. 3.6% ± 1.7%; p = 0.03), POP-FMD (2.6% ± 1.1% vs. 1.3% ± 0.8%; p = 0.006), and POP-NMD (5.1% ± 1.7% vs. 3.3% ± 2.1%; p = 0.04). In the pooled sample, MVPA was moderately correlated to both BA-FMD (r = 0.53; p = 0.01) and POP-NMD (r = 0.59; p = 0.005), and strongly correlated to POP-FMD (r = 0.85; p < 0.001). Collectively, our results provide supporting evidence that meeting MVPA guidelines is associated with better vascular function and may reduce the risk of developing cardiovascular disease in older adults. Furthermore, these data suggest that weekly MVPA time may have a greater impact on blood vessel function than aerobic fitness and weekly sedentary time.