Role of Monokine Induced by Interferon Gamma in Discrimination and Prognosis of Patients With Chagas' Disease and Idiopathic Dilated Cardiomyopathy

Measurement of multiple cytokines for discrimination and risk stratification in patients with Chagas' disease and idiopathic dilated cardiomyopathy

Chagas' disease (CD), caused by the hemoflagellate protozoan, Trypanosoma cruzi, is endemic in most countries of Latin America. Heart failure (HF) is often a late manifestation of chronic CD, and is associated with high morbidity and mortality. Inflammatory processes mediated by cytokines play a key role in the pathogenesis and progression of CD. Keeping in view the inflammatory nature of CD, this study investigated the possible role of 21 different inflammatory cytokines as biomarkers for prediction and prognosis of CD. The plasma concentration of these cytokines was measured in a group of patients with CD (n = 94), and then compared with those measured in patients with dilated cardiomyopathy (DCM) from idiopathic causes (n = 48), and with control subjects (n = 25). Monovariately, plasma levels of cytokines such as stem cell growth factor beta (SCGF beta), hepatocyte growth factor (HGF), monokine induced by interferon gamma (CXCL9), and macrophage inhibitory factor (MIF) were significantly increased in CD patients with advanced HF compared to control group. None of the cytokines could demonstrate any prognostic potency in CD patients, and only MIF and stromal derived factor-1 alpha (CXCL12) showed significance in predicting mortality and necessity for heart transplant in DCM patients. However, multivariate analysis prognosticated a large proportion of CD and DCM patients. In CD patients, HGF and Interleukin-12p40 (IL-12p40) together separated 81.9% of 3-year survivors from the deceased, while in DCM patients, CXCL12, stem cell factor (SCF), and CXCL9 together discriminated 77.1% of survivors from the deceased. The significant increase in plasma concentrations of cytokines such as HGF and CXCL9 in CD patients, and the ability of these cytokines to prognosticate a large proportion of CD and DCM patients multivariately, encourages further studies to clarify the diagnostic and prognostic potential of cytokines in such patients.

Potential Effects of CXCL9 and CCL20 on Cardiac Fibrosis in Patients with Myocardial Infarction and Isoproterenol-Treated Rats

The chemokines CXCL9 and CCL20 have been reported to be associated with ventricular dysfunction. This study was aimed to investigate the effects of CXCL9/CCL20 on cardiac fibrosis following myocardial infarction (MI). Blood samples of patients with MI were obtained to determine the serum CXCL9, CCL20, tumor necrosis factor-α (TNF-α), and transforming growth factor-β (TGF-β). The expression of CXCL9 and CCL20 in hypoxia-incubated H9c2 cells and TNF-α/TGF-β-activated peripheral blood mononuclear cells (PBMCs) were examined. The experimental MI of rats was produced by the intraperitoneal injection of isoproterenol (ISO) (85 mg/kg/day) for two consecutive days. The growth and migration of CXCL9/CCL20-incubated cardiac fibroblasts in vitro were evaluated. TNF-α/TGF-β-activated PBMCs showed an enhanced expression of CXCL9 and CCL20, while hypoxic H9c2 cells did not. Patients with MI had significantly enhanced levels of serum TGF-β and CXCL9 compared to healthy subjects. ISO-treated rats had increased serum CXCL9 levels and marked cardiac fibrosis compared to control rats. The trend of increased serum CCL20 in patients with MI and ISO-treated rats was not significant. CXCL9-incubated cardiac fibroblasts showed enhanced proliferation and migration. The findings of this study suggest that an enhanced expression of CXCL9 following MI might play a role in post-MI cardiac fibrosis by activating cardiac fibroblasts.