SLE is a chronic autoimmune disease that can lead to organ damages. JSLE counts for 15-20% of all lupus [5]. It is usually diagnosed during adolescence and remains rare before the age of 5, with the average age of diagnosis being around 11 to 12 years [6]. The incidence of this disease varies between 0.36 and 0.60 per 100,000 children and its prevalence is estimated between 1 and 6 per 100,000 children with a higher frequency in non-Caucasian populations [1, 7].
The initial manifestations are variable with an insidious and progressive onset. Non-specific symptoms are fever, anorexia, weight loss and asthenia [2]. At the onset of the disease, only one organ may be affected, but systemic involvement is the usual presenting feature [1]. Joint, mucocutaneous, haematological and renal damages are the most frequent manifestations of JSLE [8].
Cardiac involvement was first described by Libman and Sacks in 1924. The frequency of cardiac manifestations varies from 4 to 78% according to literature [9, 10, 11, 12]. Most studies of the cardiac manifestations of SLE are reported in adult patients and describe various types of abnormalities affecting all the layers of the heart with a predilection for the pericardium [3]. Few reports have investigated cardiac manifestations of lupus in children. Guevara et al. found a point prevalence of cardiac abnormalities on the ECG and / or echocardiography in 32% of children with JSLE [13], while Harrison et al. report a 31% prevalence of cardiac involvement in a study of 93 cases of juvenile lupus [14]. A study comparing a pediatric cohort (n = 297) to an adult cohort (n = 6927) of early stage SLE showed an incidence and prevalence of the occurrence of pericarditis and myocarditis at least 4 times higher in the pediatric population compared to the adult one [15]. The classic damage is pericarditis, which is observed in a quarter to a third of JSLE’s cases and which counts for 83% of heart involvement, in some rare cases it could be fatal due to the risk of tamponade [3,12,14]. Valvular involvement (Libman-Sacks endocarditis) is exceptional and generally subclinical; it is often described with positive anti-phopholipid antibodies [9]. Coronary artery damage has also been reported; it can be secondary to lesions of coronary artery disease and / or atherosclerosis, of premature onset given to the inflammation and dyslipidemia. They expose to a high risk of mortality [3]. Few cases of myocardial infarction explained by coronary lesions of vasculitis or thrombosis in the context of antiphospholipid antibody syndrome have been reported in children [3, 13].
Cardiomyopathy is reported with an estimated prevalence of 10%. Its clinical expression in JSLE is most of the time silent. In the absence of early diagnosis and management, the progression can lead to a heart failure, that may be irreversible [3, 15, 16]. In a study from Thailand of 26 patients, global left ventricular dysfunction was found to be common in patients with active JSLE, possibly reflecting myocardial involvement [17]. In addition, a longitudinal study of 92 patients with JSLE who never had developed cardiac symptoms, showed a decrease in ventricular diastolic function over time, suggesting a cardiac morbidity linked to the disease [18]. This myocardial involvement can be related to a lupus flare, 3 anecdotal cases of SLE (2 adults and a 15-year-old adolescent) have been reported [19], similarly to the case we reported above. To definitely confirm the diagnosis of cardiomyopathy of lupus origin, hypertensive cardiomyopathy, toxicity due to hydroxychloroquine, viral, metabolic causes and atherosclerosis although rare in JSLE, must be excluded and the active disease must be proven by complement’s comsuption. Although the myocardial biopsy is considered as the gold standard for diagnostic confirmation, this aggressive test is performed exceptionally or even post-mortem [20]. Currently, cardiac MRI remains the best non-invasive test to confirm the presence of myocarditis in JSLE but does not allow its origin to be specified [21]. The outcome is usually satisfactory allowing an improvement after early initiation of immunosuppressive therapy combined with symptomatic measures of heart failure, as we have seen in our patient who had both pericarditis and cardiomyopathy. Inaugural pancarditis in JSLE has been reported, although the patient had recovered with corticosteroids, there is no clear recommendation for treating this condition [22].