Serum cytokine levels associated with myocardial injury in systemic lupus erythematosus

OBJECTIVES

To identify cytokines, markers of endothelial activation [soluble vascular cell adhesion molecule-1 (sVCAM-1)] and myocyte strain [soluble ST2 (sST2)] associated with myocardial injury (MInj) in SLE, classified by cardiac magnetic resonance (CMR) criteria.

METHODS

CMR was performed on patients with SLE, identifying stages of MInj (inflammation and necrosis or fibrosis). Data captured included: clinical assessment, laboratory and serological analyses, cytokine (IL-1β, IL-1Ra, IL-2, IL-6, IL-10, IL-17, IL-18, TNF-alpha), sVCAM-1 and sST2 levels. Cytokines were compared with regard to SLE features and evidence of CMR MInj. Predictors of CMR MInj were determined through regression analyses.

RESULTS

Forty-one patients with high disease activity (SLEDAI-2K: 13; IQR: 3-17) were included. SLE features included: LN (n = 12), neurolupus (n = 6) and clinical lupus myocarditis (LM) (n = 6). Nineteen patients had CMR evidence of MInj. Patients with a SLEDAI-2K ≥ 12 had higher sVCAM-1 (P = 0.010) and sST2 (P = 0.032) levels. Neurolupus was associated with higher IL-1Ra (P = 0.038) and LN with lower IL-1Ra (P = 0.025) and sVCAM-1 (P = 0.036) levels. Higher IL-1Ra (P = 0.012), IL-17 (P = 0.045), IL-18 (P = 0.003), and sVCAM-1 (P = 0.062) levels were observed in patients with CMR MInj compared with those without. On multivariable logistic regression, IL-1Ra predicted CMR inflammation and fibrosis/necrosis (P < 0.005) while anti-Ro/SSA [odds ratio (OR): 1.197; P = 0.035] and the SLE damage index (OR: 4.064; P = 0.011) predicted fibrosis/necrosis.

CONCLUSION

This is a novel description of associations between cytokines and SLE MInj. IL-18 and IL-1Ra were significantly higher in patients with MInj. IL-1Ra independently predicted different stages of CMR MInj. Exploration of the role of these cytokines in the pathogenesis of SLE MInj may promote targeted therapies for LM.

Myocardial injury in systemic lupus erythematosus according to cardiac magnetic resonance tissue characterization: clinical and echocardiographic features

OBJECTIVES

To determine the prevalence of myocardial injury (MInj) in systemic lupus erythematosus (SLE) according to cardiac magnetic resonance (CMR) criteria. To compare clinical and echocardiographic features of patients with and without MInj and identify predictors of myocardial tissue characteristics according to CMR.

METHODS

SLE inpatients underwent CMR screening for MInj based on the Lake Louise Criteria (LLC). Tissue characteristics included inflammation (increased T2-weighted signal or early gadolinium enhancement ratio (EGEr)) and necrosis or fibrosis (late gadolinium enhancement (LGE)). Echocardiographic parameters included left (left ventricular ejection fraction (LVEF)) and right ventricular function (tricuspid annular plane systolic excursion (TAPSE)), global longitudinal strain (GLS), wall motion score (WMSi) and left ventricular internal diameter index (LVIDi). Variables were compared with regards to the presence/absence of CMR criteria. Logistic regression identified variables predictive of CMR tissue characteristics.

RESULTS

A hundred and six SLE patients were screened of whom 49 patients were included. Fifty-seven patients were excluded due to intolerance of or contraindication to CMR (27/57 due to renal impairment). Twenty-three patients had CMR evidence of MInj, of which 60.9% was subclinical. Inflammation occurred in 16/23 and necrosis/fibrosis in 12/23 patients. Patients with any evidence of MInj were more frequently anti-dsDNA positive (p = 0.026) and patients fulfilling LLC for myocarditis had higher SLE disease activity (p = 0.022). The LVIDi (p = 0.005), LVEF (p = 0.005) and TAPSE (p = 0.011) were more abnormal in patients with an increased EGEr, whereas WMSi (p = 0.002) and GLS (0.020) were more impaired in patients with LGE. On multivariable logistic regression analyses, TAPSE predicted inflammation (OR: 0.045, p = 0.006, CI: 0.005-0.415) and GLS predicted necrosis/fibrosis (OR: 1.329, p = 0.031, CI: 1.026-1.722). A model including lymphocyte count, TAPSE and LVIDi predicted an increased EGEr on CMR (receiver operating characteristic-curve analyses: area under the curve: 0.901, p < 0.001, sensitivity: 88.9%, specificity: 76.3%).

CONCLUSIONS

CMR evidence of MInj frequently occurs in SLE and is often subclinical. The utility of CMR in SLE is limited by a high exclusion rate, mainly due to renal involvement. Models including echocardiographic parameters (TAPSE, LVIDi and GLS) are predictive of CMR myocardial injury. Echocardiography can be used as a cost-effective screening tool with a high negative predictive value, in particular when CMR is contraindicated or unavailable.

Lack of specificity of anticyclic citrullinated peptide antibodies in advanced human immunodeficiency virus infection

OBJECTIVE

To determine the prevalence and specificity of anticyclic citrullinated peptide antibodies (anti-CCP) and rheumatoid factor (RF) for rheumatoid arthritis (RA) in human immunodeficiency virus (HIV) infection and to evaluate the effect of immune reconstitution on these markers.

METHODS

Patients with advanced HIV infection without arthritis were enrolled. CD4+ T lymphocyte counts (CD4), anti-CCP, and RF were determined before initiating antiretroviral therapy (ART) and repeated after 6 months. Results were compared to those of healthy controls. Patients were followed for the development of RA for 1 year.

RESULTS

Sixty patients and 26 controls were studied. Six-month followup results were available on 49 patients. Mean (SD) levels of anti-CCP were higher in patients with HIV compared to controls: respectively, 9.50 (11.41) versus 0.80 (1.32) units (p < 0.001). Mean (SD) levels decreased to 4.85 (8.12) units (p = 0.006) after 6 months of ART (HIV-infected group). Fifteen percent of patients initially tested positive for anti-CCP, 4% after 6 months versus no controls (p = 0.031). Forty-seven percent of patients initially tested positive for RF, 18% after 6 months versus 8% of controls (p < 0.001). Decreases in RF and anti-CCP after ART were accompanied by increased mean (SD) CD4: from 129 (56) to 278 (140) cells/mm(3) (p < 0.001). Anti-CCP and RF positivity was not associated with the development of RA.

CONCLUSION

Increased titers of anti-CCP and RF occur in advanced HIV infection. Although more specific than RF, before immune reconstitution, anti-CCP is an unreliable diagnostic marker for RA and does not necessarily predict future RA. After immune reconstitution, the specificity of anti-CCP approaches that of a control group.