Wendy Marder

The Circadian Clock in Oral Health and Diseases

Most physiological processes in mammals display circadian rhythms that are driven by the endogenous circadian clock. This clock is comprised of a central component located in the hypothalamic suprachiasmatic nucleus and subordinate clocks in peripheral tissues. Circadian rhythms sustain 24-hour oscillations of a large number of master genes controlling the correct timing and synchronization of diverse physiological and metabolic processes within our bodies. This complex regulatory network provides an important communication link between our brain and several peripheral organs and tissues. At the molecular level, circadian oscillations of gene expression are regulated by a family of transcription factors called “clock genes”. Dysregulation of clock gene expression results in diverse human pathological conditions, including autoimmune diseases and cancer. There is increasing evidence that the circadian clock affects tooth development, salivary gland and oral epithelium homeostasis, and saliva production. This review summarizes current knowledge of the roles of clock genes in the formation and maintenance of oral tissues, and discusses potential links between “oral clocks” and diseases such as head and neck cancer and Sjögren’s syndrome.

Population-Based Incidence and Prevalence of Systemic Lupus Erythematosus: The Michigan Lupus Epidemiology and Surveillance Program

OBJECTIVE To estimate the incidence and prevalence of systemic lupus erythematosus (SLE) in a sociodemographically diverse southeastern Michigan source population of 2.4 million people. METHODS SLE cases fulfilling the American College of Rheumatology classification criteria (primary case definition) or meeting rheumatologist-judged SLE criteria (secondary definition) and residing in Wayne or Washtenaw Counties during 2002-2004 were included. Case finding was performed from 6 source types, including hospitals and private specialists. Age-standardized rates were computed, and capture-recapture was performed to estimate underascertainment of cases. RESULTS The overall age-adjusted incidence and prevalence (ACR definition) per 100,000 persons were 5.5 (95% confidence interval [95% CI] 5.0-6.1) and 72.8 (95% CI 70.8-74.8). Among females, the incidence was 9.3 per 100,000 persons and the prevalence was 128.7 per 100,000 persons. Only 7 cases were estimated to have been missed by capture-recapture, adjustment for which did not materially affect the rates. SLE prevalence was 2.3-fold higher in black persons than in white persons, and 10-fold higher in females than in males. Among incident cases, the mean ± SD age at diagnosis was 39.3 ± 16.6 years. Black SLE patients had a higher proportion of renal disease and end-stage renal disease (ESRD) (40.5% and 15.3%, respectively) as compared to white SLE patients (18.8% and 4.5%, respectively). Black patients with renal disease were diagnosed as having SLE at younger age than white patients with renal disease (mean ± SD 34.4 ± 14.9 years versus 41.9 ± 21.3 years; P = 0.05). CONCLUSION SLE prevalence was higher than has been described in most other population-based studies and reached 1 in 537 among black female persons. There were substantial racial disparities in the burden of SLE, with black patients experiencing earlier age at diagnosis, >2-fold increases in SLE incidence and prevalence, and increased proportions of renal disease and progression to ESRD as compared to white patients.

Population-Based Incidence and Prevalence of Systemic Lupus Erythematosus

OBJECTIVE To estimate the incidence and prevalence of systemic lupus erythematosus (SLE) in a sociodemographically diverse southeastern Michigan source population of 2.4 million people. METHODS SLE cases fulfilling the American College of Rheumatology classification criteria (primary case definition) or meeting rheumatologist-judged SLE criteria (secondary definition) and residing in Wayne or Washtenaw Counties during 2002-2004 were included. Case finding was performed from 6 source types, including hospitals and private specialists. Age-standardized rates were computed, and capture-recapture was performed to estimate underascertainment of cases. RESULTS The overall age-adjusted incidence and prevalence (ACR definition) per 100,000 persons were 5.5 (95% confidence interval [95% CI] 5.0-6.1) and 72.8 (95% CI 70.8-74.8). Among females, the incidence was 9.3 per 100,000 persons and the prevalence was 128.7 per 100,000 persons. Only 7 cases were estimated to have been missed by capture-recapture, adjustment for which did not materially affect the rates. SLE prevalence was 2.3-fold higher in black persons than in white persons, and 10-fold higher in females than in males. Among incident cases, the mean ± SD age at diagnosis was 39.3 ± 16.6 years. Black SLE patients had a higher proportion of renal disease and end-stage renal disease (ESRD) (40.5% and 15.3%, respectively) as compared to white SLE patients (18.8% and 4.5%, respectively). Black patients with renal disease were diagnosed as having SLE at younger age than white patients with renal disease (mean ± SD 34.4 ± 14.9 years versus 41.9 ± 21.3 years; P = 0.05). CONCLUSION SLE prevalence was higher than has been described in most other population-based studies and reached 1 in 537 among black female persons. There were substantial racial disparities in the burden of SLE, with black patients experiencing earlier age at diagnosis, >2-fold increases in SLE incidence and prevalence, and increased proportions of renal disease and progression to ESRD as compared to white patients.

Interleukin 17 as a novel predictor of vascular function in rheumatoid arthritis

Background Rheumatoid arthritis (RA) is associated with enhanced cardiovascular (CV) risk and subclinical vascular disease. The proinflammatory milieu has been linked to premature atherosclerosis and endothelial dysfunction in RA. While interleukin 17 (IL-17) is considered pathogenic in RA, its role in determining vascular dysfunction in this disease has not been systematically assessed. Objectives To analyse candidate variables that might determine endothelial function in various vascular territories in a cohort of patients with RA receiving treatment with biological agents, with minimal traditional CV risk factors and low disease activity score. Methods Patients with RA (n=50) receiving stable treatment with biological agents underwent measurement of conduit artery endothelial function by brachial artery flow-mediated dilatation; arterial compliance by pulse wave velocity (PWV) assessment; and endothelium-dependent microvascular testing with Endo-Pat2000 device to assess the reactive hyperaemia index (RHI). IL-17 was quantified by ELISA and disease activity was assessed by 28-joint count Disease Activity Score. Results IL-17 was the main determinant of lower RHI in univariate and multivariate analysis. Traditional and non-traditional CV risk variables determined PWV, with a signifi cant positive association with IL-17 in univariate and multivariate analysis. In contrast, conduit endothelial function was mainly determined by rheumatoid factor titres in univariate and multivariate analysis. Anti-cyclic citrullinated peptide titres, specific disease-modifying antirheumatic drugs or biological agents and disease activity did not determine vascular function. Conclusion In patients with RA treated with biological agents, IL-17 is a main predictor of microvascular function and arterial compliance. This study suggests that IL-17 may play a significant role in development of endothelial dysfunction and cardiovascular disease in RA.

Adjunctive GnRH-a treatment attenuates depletion of ovarian reserve associated with cyclophosphamide therapy in premenopausal SLE patients

Background: We measured antimullerian hormone (AMH), a marker of ovarian reserve, in women with lupus treated with cyclophosphamide (CYC) (group I), CYC plus gonadotropin-releasing hormone agonist (GnRH-a) (group II) or neither (group III). We hypothesized that AMH would be diminished in women exposed to CYC versus women receiving adjunctive GnRH-a treatment or no CYC exposure. Methods: Forty-eight premenopausal lupus patients were retrospectively divided into three treatment groups: CYC alone (group I, n = 11), CYC + GnRH-a (group II, n = 10) and neither (group III, n = 27). Serum AMH levels between groups were compared using a nonparametric test (Wilcoxon rank-sum). Multiple linear regression adjusting for age was performed. Results: AMH (ng/mL) levels at the last collection were significantly lower in group I versus group III (mean ± SD: 0.18 ± 0.20 group I vs 1.33 ± 1.59 group III; p = 0.015), and versus group II (mean ± SD: 0.86 ± 1.06; p = 0.018). When centered on age 30 years, average AMH levels for group I, group II and group III were 0.20, 0.44 and 1.00, respectively. When adjusted for age, AMH between all groups was significantly different (p<0.0001). Conclusion: Posttreatment AMH levels were significantly higher among patients receiving CYC + GnRH-a compared to CYC alone, suggesting that GnRH-a coadministration mitigates CYC-induced ovarian injury.

In Utero Azathioprine Exposure and Increased Utilization of Special Educational Services in Children Born to Mothers With Systemic Lupus Erythematosus

Azathioprine (AZA) is recognized among immunosuppressive medications as relatively safe during pregnancy for women with systemic lupus erythematosus (SLE) requiring aggressive treatment. This pilot study aimed to determine whether SLE therapy during pregnancy was associated with developmental delays in offspring.

Vitamin D Deficiency, Interleukin 17, and Vascular Function in Rheumatoid Arthritis

Objective. Vitamin D deficiency is associated with increased cardiovascular (CV) disease risk in the general population. We examined the association between vitamin D deficiency and CV risk in rheumatoid arthritis (RA). Methods. We measured large artery compliance by pulse wave velocity and microvascular function by the reactive hyperemia index in patients with stable RA (n = 87). We quantified CV risk factors, serum 25-hydroxyvitamin D [25(OH)D], and interleukin 17 (IL-17), and RA disease activity by Disease Activity Score of 28 joints. We used linear regression to test associations between serum 25(OH)D and CV risk factors. Results. The mean serum 25(OH)D level in the cohort was 27.1 ± SD 13.6 ng/ml. Fifty-nine patients (68%) were vitamin D-insufficient (25(OH)D < 30 ng/ml; mean 20.2 ± 5.9 ng/ml) and of these, 25 (29%) were vitamin D-deficient (25(OH)D < 20 ng/ml; mean 14.4 ± 3.4 ng/ml). In the whole cohort and the vitamin D-insufficient group, serum 25(OH)D was inversely associated with IL-17 (log IL-17; β = −0.83, p = 0.04; β = −0.63, p = 0.004, respectively) by univariate analysis, which persisted after adjustment for season, and in multivariate analysis after adjustment for confounders (log IL-17; β = −0.74, p = 0.04; β = −0.53, p = 0.02). In vitamin D-deficient patients, serum 25(OH)D was positively associated with microvascular function by univariate and multivariate analysis after adjustment for confounders (β = 2.1, p = 0.04; β = 2.7, p = 0.04). Conclusion. Vitamin D deficiency in RA may affect Th17 responses and microvascular function. Maintaining normal serum vitamin D levels may protect against IL-17-mediated inflammation and vascular dysfunction in RA.

The Peroxisome Proliferator Activated Receptor-γ Pioglitazone Improves Vascular Function and Decreases Disease Activity in Patients With Rheumatoid Arthritis

Background Rheumatoid arthritis (RA) is associated with heightened mortality due to atherosclerotic cardiovascular disease (CVD). Inflammatory pathways in RA negatively affect vascular physiology and promote metabolic disturbances that contribute to CVD. We hypothesized that the peroxisome proliferator activated receptor‐γ (PPAR‐γ) pioglitazone could promote potent vasculoprotective and anti‐inflammatory effects in RA. Methods and Results One hundred forty‐three non‐diabetic adult RA patients (76.2% female, age 55.2±12.1 [mean±SD]) on stable RA standard of care treatment were enrolled in a randomized, double‐blind placebo controlled crossover trial of 45 mg daily pioglitazone versus placebo, with a 3‐month duration/arm and a 2‐month washout period. Pulse wave velocity of the aorta (PWV), brachial artery flow mediated dilatation (FMD), nitroglycerin mediated dilatation (NMD), microvascular endothelial function (reactive hyperemia index [RHI]), and circulating biomarkers of inflammation, insulin resistance, and atherosclerosis risk all were quantified. RA disease activity was assessed with the 28‐Joint Count Disease Activity Score (DAS‐28) C‐reactive protein (CRP) and the Short Form (36) Health Survey quality of life questionnaire. When added to standard of care RA treatment, pioglitazone significantly decreased pulse wave velocity (ie, aortic stiffness) (P=0.01), while FMD and RHI remained unchanged when compared to treatment with placebo. Further, pioglitazone significantly reduced RA disease activity (P=0.02) and CRP levels (P=0.001), while improving lipid profiles. The drug was well tolerated. Conclusions Addition of pioglitazone to RA standard of care significantly improves aortic elasticity and decreases inflammation and disease activity with minimal safety issues. The clinical implications of these findings remain to be established. Clinical Trial Registration URL: ClinicalTrials.gov Unique Identifier: NCT00554853.

Plasminogen Activator Inhibitor‐1 Is Associated with Impaired Endothelial Function in Women with Systemic Lupus Erythematosus

Abstract: Endothelial function, measured noninvasively by brachial artery flow‐mediated dilatation (FMD), has been shown to be impaired in patients with systemic lupus erythematosus (SLE). We hypothesized that depressed FMD in SLE patients is associated with increased levels of plasminogen activator inhibitor‐1 (PAI‐1), an inhibitor of fibrinolysis and regulator of vasoactivity. In this cross‐sectional study of female SLE patients under the age of 55, putative markers of cardiovascular disease (CVD) such as PAI‐1 were measured in addition to lupus‐related disease activity (SLEDAI). The primary outcome, FMD, was measured using high‐resolution ultrasound of the brachial artery gated to the R wave to determine endothelial‐dependent vasomotion. Endothelial‐independent vasomotion was measured in response to nitroglycerin (NMD). Seventy‐six female SLE patients, mean age 38.3 ± 9.4 years, were included. All patients demonstrated normal NMD responses, indicating that depression of FMD was related to decreased endothelial nitric oxide production. Increased PAI‐1 was related to depressed FMD by univariate regression (P= 0.004). In a multivariable regression model adjusting for t‐PA (tissue plasminogen activator)/PAI‐1 ratio, SLEDAI, age at visit, family history of cardiovascular disease, SLE disease duration and body mass index, every 1 ng/mL increase in PAI‐1 was associated with a reduction of 0.07 units FMD (P= 0.039). PAI‐1 was associated with impaired endothelial dysfunction, after controlling for several potential confounders. Given the high incidence of cardiovascular disease in SLE, further investigation of the role of subclinical markers of CVD is needed.

Placental histology and neutrophil extracellular traps in lupus and pre-eclampsia pregnancies

Objective Systemic lupus erythematosus (SLE) is associated with increased risk of adverse pregnancy outcomes, including pre-eclampsia, particularly in association with antiphospholipid antibody syndrome (APS). While significant placental abnormalities are expected in pre-eclampsia, less is known about how lupus activity and APS in pregnancy affect the placenta. We describe placental pathology from a population of lupus pregnancies, several of which were complicated by APS-related thromboses, in which pre-eclampsia and other complications developed. We performed standard histopathological placental review and quantified neutrophils and neutrophil extracellular traps (NETs) in the intervillous space, given the recognised association of NETs with lupus, APS and pre-eclampsia. Methods Pre-eclampsia, SLE and control placentas were scored for histological features, and neutrophils were quantified on H&E and immunohistochemical staining for the granular protein myeloperoxidase. NETs were identified by extracellular myeloperoxidase staining in the setting of decondensed nuclei. Non-parametric analysis was used to evaluate differences in netting and intact neutrophils between groups, with Kruskal–Wallis testing for associations between histological findings and neutrophils. Results Placentas were evaluated from 35 pregnancies: 10 controls, 11 pre-eclampsia, 4 SLE+pre-eclampsia and 10 SLE, including one complicated by catastrophic APS and one complicated by hepatic and splenic vein thromboses during pregnancy. Intrauterine growth restriction and oligohydramnios were observed in lupus cases but not controls. Significantly more NETs were found infiltrating placental intervillous spaces in pre-eclampsia, SLE+pre-eclampsia and all 10 SLE non-pre-eclampsia cases. The ratio of NETs to total neutrophils was significantly increased in all case groups compared with controls. When present, NETs were associated with maternal vasculitis, laminar decidual necrosis, maternal–fetal interface haemorrhage and non-occlusive fetal thrombotic vasculopathy. Conclusions In this pilot study of placental tissue from lupus pregnancies, outcomes were more complicated, particularly if associated with APS. Placental tissue revealed marked inflammatory and vascular changes that were essentially indistinguishable from placental tissue of pre-eclampsia pregnancies.