Heart, rheumatism and autoimmunity: an old intriguing link

Effectiveness and safety of low dose Rituximab as remission-maintenance treatment for patients with refractory idiopathic inflammatory myopathies: results of a retrospective study from a monocentric cohort

OBJECTIVE

Our aim was to assess efficacy and safety of Rituximab (RTX) in patients with refractory Idiopathic inflammatory myopathies (IIM) from a monocentric cohort. Thereafter, we evaluated the efficacy of a low-dose RTX regimen as a remission-maintenance therapy.

METHODS

We retrospectively evaluated a cohort of patients affected with IIM treated with RTX. All patients were refractory to glucocorticoids (GC) and at least one immunosuppressant. Two infusions of 1 g two weeks apart were considered as standard cycle of RTX, a single dose of 1 g every six months was deemed as a low-dose RTX regimen. Complete and partial response were defined according to physician's judgment, laboratory and radiological features.

RESULTS

Thirty-six patients affected with IIM were enrolled. Eighteen patients (50%) required the use of RTX for muscular involvement, 6 (16.7%) for interstitial lung disease (ILD), 12 (33.3%) for both myositis and ILD. We observed complete response to RTX in 25 patients (69.4%), partial response in 7 (19.4%) and no response in 4 (11.1%), with an overall response of 88.8% (partial and complete response). From the subgroup of twenty-five patients that achieved a complete response, six were treated with a low dose maintenance therapy maintaining a complete response to RTX. Twenty-six patients who achieved a complete or partial response were able to decrease the mean daily GC dose. Infections were the major adverse events detected in our study.

CONCLUSIONS

RTX shows favorable outcomes in refractory patients with IIM. A low-dose regimen of RTX appears to be effective in maintaining remission after induction with standard dose. Key Points • The precise pathogenic mechanism of idiopathic inflammatory myopathies (IIM) remains elusive; however, a growing body of data support the autoimmune hypothesis. In this context, rituximab, a B cell-depleting agent, has emerged as a second-line therapeutic option in IIM. • Several studies have assessed It its effectiveness in refractory IIM patients. • Limited information exists on the use of Rituximab as maintenance therapy in patients who have achieved remission following induction therapy with Rituximab.

Acute Coronary Syndromes in Antiphospholipid Syndrome-above Suspicion: A Systematic Review

Antiphospholipid syndrome(APS) is an autoimmune disorder characterized clinically by vascular thrombosis and/or pregnancy morbidity, associated with persistently elevated titers of antiphospholipid antibodies on at least two measurements over 12 weeks apart. In this study, we conducted a systematic review of the literature utilizing the Pubmed platform, in order to acquire clinical information about acute coronary syndromes in patients with APS. The obtained articles were reviewed in order to register the clinical characteristics, the rate of occurrence, the prognosis and the therapeutic approach of these patients. APS should be considered in young patients with acute myocardial infarction, even in patients with normal coronary arteries. The pharmaceutical approach is mainly based on the vitamin K antagonists, and in certain occasions aspirin, without any definite guidelines on the subject. Further randomized clinical trials are imperative for a better understanding of the particular characteristics of this group of patients, so that a more complete therapeutic approach to be obtained.

Coxsackievirus-induced myocarditis in mice: a model of autoimmune disease for studying immunotoxicity

Excellent animal models are available for virus-induced and autoimmune heart disease that are remarkably similar to human disease. Developing good animal models for heart disease is crucial because cardiovascular disease is now the leading cause of death in the United States and is estimated to be the leading cause of death in the world by the year 2020. A significant proportion of heart disease in Western populations is associated with inflammation. Myocarditis, or inflammation of the heart muscle, is the major cause of sudden death in young adults. Although most individuals recover from acute myocarditis, genetically susceptible individuals may go on to develop chronic myocarditis and dilated cardiomyopathy (DCM) resulting in congestive heart failure. In this article, we describe a model of autoimmune myocarditis and DCM induced by inoculation with heart-passaged coxsackievirus B3 (CVB3). Intraperitoneal inoculation of susceptible mice with CVB3 induces acute cardiac inflammation from days 7 to 14 postinfection (pi) that progresses to chronic myocarditis and DCM from day 28 to at least 56 pi. The model of CVB3-induced myocarditis presented here allows dissection of the contribution of viral infection and xenobiotics on immune dysregulation and inflammation in the heart. An improved understanding of the interaction between environmental exposures and the development of heart disease represents a clear challenge for immunotoxicologists.

Cardiac manifestations in the antiphospholipid syndrome

Experimental evidence reveals that aPL are not only markers of APS, but also may play a causative role in the development of vascular thrombosis and pregnancy morbidity. The pathogenic mechanisms of aPL seem to be heterogeneous, including endothelial cell activation, the direct inhibition of the activated protein C pathway, abnormalities in platelet function, and in complement activation. aPLs induce proadhesive, proinflammatory, and procoagulant molecules that provide a persuasive explanation for induction of thrombosis in APS. Cardiac manifestations in APS include valve abnormalities (valve thickening and vegetations), occlusive arterial disease (atherosclerosis and myocardial infarction), intracardiac emboli, ventricular dysfunction, and pulmonary hypertension. aPL may be associated with accelerated atherosclerosis in APS patients. Valve disease is the most important and most common cardiac manifestation of APS. The precise mechanism by which valves become deformed is not yet fully known.