Serum Biomarkers of Inflammation, Fibrosis, and Cardiac Function in Facilitating Diagnosis, Prognosis, and Treatment of Anti-SSA/Ro-Associated Cardiac Neonatal Lupus.

BACKGROUND: Cardiac manifestations of neonatal lupus (cardiac NL) include congenital heart block and cardiomyopathy. Several candidate biomarkers were evaluated in cases at risk for cardiac NL on the basis of potential roles in inflammation, fibrosis, and cardiac dysfunction: C-reactive protein (CRP); NT-pro-B-type natriuretic peptide (NT-proBNP); troponin I; matrix metalloproteinase (MMP)-2; urokinase plasminogen activator (uPA); urokinase plasminogen activator receptor (uPAR); plasminogen; and vitamin D. OBJECTIVES: Identification of maternal and fetal biomarkers associated with development and morbidity of cardiac NL should provide clues to pathogenesis with translational implications for management. METHODS: Cord (139) and maternal (135) blood samples collected during pregnancies at risk for cardiac NL were available for study. Levels of cord and maternal CRP, cord NT-proBNP, and cord troponin I were evaluated using multiplex assays. Cord and maternal vitamin D were assessed by liquid chromatography-mass spectrometry. MMP-2, uPA, uPAR, and plasminogen were evaluated using ELISA. RESULTS: Cord CRP, NT-proBNP, MMP-2, uPA, uPAR, and plasminogen levels were higher in cardiac NL-affected fetuses than in unaffected cases, independent of maternal rheumatic disease, season at highest risk of cardiac NL development, and medications taken during pregnancy. These biomarkers were positively associated with a disease severity score derived from known risk factors for mortality in cardiac NL. Maternal CRP and cord troponin I levels did not differ between the groups. Cord and maternal vitamin D levels were not significantly associated with cardiac NL, but average maternal vitamin D level during pregnancy was positively associated with longer time to postnatal pacemaker placement. CONCLUSIONS: These data support the association of fetal reactive inflammatory and fibrotic components with development and morbidity of cardiac NL. Following CRP and NT-proBNP levels after birth can potentially monitor severity and progression of cardiac NL. MMP-2 and the uPA/uPAR/plasminogen cascade provide therapeutic targets to decrease fibrosis. Although decreased vitamin D did not confer increased risk, given the positive influence on postnatal outcomes, maternal levels should be optimized.

Dysregulation of the microvasculature in nonlesional non-sun-exposed skin of patients with lupus nephritis.

OBJECTIVE: Membrane endothelial protein C receptor (mEPCR) is highly expressed in peritubular capillaries of kidneys from patients with active and poorly responsive lupus nephritis (LN). We investigated the hypothesis that changes in the microvasculature are widespread with extension to the dermal vasculature. METHODS: Skin biopsies from uninvolved skin (buttocks) were performed in 27 patients with LN and 5 healthy controls. Sections were stained with specific antibodies reactive with mEPCR, adiponectin, intercellular adhesion molecule-1 (ICAM-1), and CD31; then assessed by enumeration of stained blood vessels (percentage positive blood vessels) blinded to knowledge of clinical information. RESULTS: There was a significant increase in the prevalence of blood vessels that stained for mEPCR and ICAM-1 in patients compared to controls [94% vs 59% (p = 0.045) and 81% vs 67% (p = 0.037), respectively]. Adiponectin staining and CD31 staining were similar between the groups (45% vs 43% and 98% vs 92%). Dermal staining for mEPCR was greater in patients with proliferative glomerulonephritis than in those with membranous disease (96% vs 60%; p = 0.029). A composite of poor prognostic renal markers and death was significantly associated with greater expression of mEPCR staining. CONCLUSION: These data are consistent with the notion that in patients with LN, activation of the microvasculature extends beyond the clinically targeted organ. The insidious expression of this widespread vasculopathy may be a contributor to longterm comorbidities.

Association of plasma soluble E-selectin and adiponectin with carotid plaque in patients with systemic lupus erythematosus.

BACKGROUND: Systemic lupus erythematosus (SLE) is associated with premature atherosclerosis but the mechanisms underlying this association are not understood. The role of endothelial dysfunction is hypothesized. METHODS: In predominantly non-Caucasian patients with SLE (N=119) and controls (N=71), carotid ultrasonography was performed and circulating endothelial cells (CECs), soluble endothelial protein C receptor and gene polymorphism at A6936G, soluble E-selectin (sE-selectin), and adiponectin were assessed. RESULTS: Carotid plaque was more prevalent among patients than controls (43% vs 17%, p=0.0002). Mean CCA IMT was greater in patients compared to controls (0.59+/-0.19 mm vs 0.54+/-0.11 mm, p=0.03). Among SLE patients, plaque was not associated with smoking, body-mass index, LDL, triglycerides, homocysteine, C-reactive protein, anti-ds DNA antibody, C3, C4, SLE activity, or medications. Age and levels of soluble E-selectin and adiponectin were significantly higher in the SLE patients with plaque compared to those without plaque in univariate and multivariate analyses. sE-selectin and adiponectin were found to serve as independent predictors of carotid plaque and that elevations were persistent over more than one visit. Unexpectedly, these biomarkers were present despite clinical quiescence. CONCLUSION: Premature atherosclerosis is a consistent feature of SLE and extends across ethnicities. Higher levels of adiponectin may represent a physiological attempt to limit further endothelial damage already reflected by the elevation in sE-selectin and the observed increase in plaque represents overwhelming of this reparative process by atherogenic stimuli.

Expression of endothelial protein C receptor in cortical peritubular capillaries associates with a poor clinical response in lupus nephritis.

OBJECTIVE: To study the membrane expression of endothelial protein C receptor (mEPCR) in the renal microvasculature in lupus nephritis (LN) as a potential marker of injury and/or prognostic indicator for response to therapy. METHODS: mEPCR expression was analysed by immunohistochemistry in normal kidney and in 59 biopsies from 49 patients with LN. Clinical parameters were assessed at baseline, 6 months and 1 year. RESULTS: mEPCR was expressed in the medulla, arterial endothelium and cortical peritubular capillaries (PTCs) in all biopsies with LN but not in the cortical PTCs of normal kidney. Positive mEPCR staining in >25% of the PTCs was observed in 16/59 biopsies and associated with poor response to therapy. Eleven (84.6%) of 13 patients with positive staining for mEPCR in >25% of the PTCs and follow-up at 6 months did not respond to therapy, compared with 8/28 (28.6%) with mEPCR staining in < or =25% PTCs, P = 0.0018. At 1 year, 10 (83.3%) of 12 patients with positive mEPCR staining in >25% of the PTCs did not respond to therapy (with two progressing to end-stage renal disease) compared with 8/24 (33.3%) with positive staining in < or =25% of the PTCs, P = 0.0116. Although tubulo-interstitial damage (TID) was always accompanied by mEPCR, this endothelial marker was extensively expressed in the absence of TID suggesting that poor response could not be attributed solely to increased TID. mEPCR expression was independent of International Society of Nephrology/Renal Pathology Society class, activity and chronicity indices. CONCLUSION: Increased mEPCR expression in PTCs may represent a novel marker of poor response to therapy for LN.

Current therapies for lupus nephritis in an ethnically heterogeneous cohort.

OBJECTIVE: To evaluate responses to mycophenolate mofetil (MMF) and intravenous cyclophosphamide (CYC) in lupus nephritis in a multiethnic population. METHODS: This was a retrospective study of all patients with systemic lupus erythematosus (SLE) that underwent kidney biopsy at New York University Medical Center. Patients with followup of at least 6 months were included. Clinical response was defined as complete (return to +/- 10% of normal) or partial (improvement of 50% in abnormal renal measurements). RESULTS: Ninety-nine patients were included in the study: 86% females, 86% non-Caucasian, age 34.2 +/- 1.1 years, 62% with proliferative nephritis (PN; ISN/RPS-III and IV), and 32% with membranous nephritis (MN; ISN/RPS-V). Of the 70 patients with PN, 37 were treated with CYC and 33 with MMF. The baseline characteristics of the 2 treatment groups were different in the incidence of ISN/RPS-IV, values of serum creatinine and serum albumin, and type of insurance (p < 0.05). The response rate was greater in the MMF than in the CYC group (70% vs 41%). Responses to MMF were different in Asians (11/11), Caucasians (4/5), African Americans (3/5), and Hispanics (5/11). Responses to CYC had a similar distribution (Asians 6/10, Caucasians 4/5, African Americans 4/9, Hispanics 1/11). In the MN group (N = 23) responses were similar to the PN group (73% MMF and 38% CYC). After adjusting for race, serum creatinine, serum albumin, type of insurance, and class of nephritis, in a logistic regression model, response to MMF was superior to CYC: OR 6.2 (95% CI 1.9-20.2). Hispanics had worse outcome than Caucasians (OR 0.17). Longterm followup suggested no difference in maintenance with MMF or CYC. CONCLUSION: After controlling for the fact that less severe nephritis is preferentially treated with MMF, we found overall that response to MMF was superior to CYC. In this US population, ethnicity was observed to have an influence on response.

Serum type I interferon activity is dependent on maternal diagnosis in anti-SSA/Ro-positive mothers of children with neonatal lupus.

OBJECTIVE: The type I interferon (IFN) pathway is activated in many patients with systemic lupus erythematosus (SLE), and high serum levels of IFN are associated with anti-SSA/Ro autoantibodies. To investigate the clinical features associated with type I IFN production in vivo, we compared serum IFN activity in individuals with anti-SSA/Ro antibodies who were asymptomatic with that in individuals with clinical manifestations of SLE or Sjögren's syndrome (SS). METHODS: Antibody-positive sera from 84 mothers of children with manifestations of neonatal lupus were studied for type I IFN activity, using a functional reporter cell assay. Maternal health status was characterized as asymptomatic, SS, SLE, pauci-SLE, or pauci-SS, based on a screening questionnaire, telephone interview, and review of medical records. The prefix "pauci-" indicates symptoms insufficient for a formal classification of the disease. RESULTS: Only 4% of asymptomatic mothers had high serum type I IFN activity, compared with 73% with pauci-SLE (P = 5.7 x 10(-5)), 35% with SLE (P = 0.011), and 32% of patients with SS (P = 0.032). One of the 4 patients with pauci-SS had high levels of IFN. The majority of patients for whom longitudinal data were available had stable type I IFN activity over time, and changes in IFN activity were not clearly accompanied by changes in the clinical diagnosis. CONCLUSION: Patients with SLE, patients with pauci-SLE, and patients with SS are more likely to have high serum IFN activity than asymptomatic individuals with SSA/Ro autoantibodies, suggesting that these autoantibodies are insufficient for activation of the type I IFN pathway, and that disease-specific factors are important for type I IFN generation in vivo.

Neonatal lupus syndromes.

Neonatal lupus has become an important model of passively acquired autoimmunity since the seminal observation in the late 1970s that sera from nearly all mothers of children with isolated congenital heart block (CHB) contain specific autoantibodies.