Risk factors associated with Pneumocystis jirovecii pneumonia in juvenile myositis in North America.

OBJECTIVES: Pneumocystis jirovecii pneumonia (PJP) is associated with significant morbidity and mortality in adult myositis patients; however, there are few studies examining PJP in juvenile myositis [juvenile idiopathic inflammatory myopathy (JIIM)]. The purpose of this study was to determine the risk factors and clinical phenotypes associated with PJP in JIIM. METHODS: An research electronic data capture (REDCap) questionnaire regarding myositis features, disease course, medications and PJP infection characteristics was completed by treating physicians for 13 JIIM patients who developed PJP (PJP+) from the USA and Canada. Myositis features and medications were compared with 147 JIIM patients without PJP (PJP-) from similar geographic regions who enrolled in National Institutes of Health natural history studies. RESULTS: PJP+ patients were more often of Asian ancestry than PJP- patients [odds ratio (OR) 8.7; 95% CI 1.3, 57.9]. Anti- melanoma differentiation associated protein 5 (MDA5) autoantibodies (OR 12.5; 95% CI 3.0, 52.4), digital infarcts (OR 43.8; 95% CI 4.2, 460.2), skin ulcerations (OR 12.0; 95% CI 3.5, 41.2) and interstitial lung disease (OR 10.6; 95% CI 2.1, 53.9) were more frequent in PJP+ patients. Before PJP diagnosis, patients more frequently received pulse steroids, rituximab and more immunosuppressive therapy compared with PJP- patients. Seven PJP+ patients were admitted to the intensive care unit and four patients died due to PJP or its complications. CONCLUSIONS: PJP is a severe infection in JIIM that can be associated with mortality. Having PJP was associated with more immunosuppressive therapy, anti-MDA5 autoantibodies, Asian race and certain clinical features, including digital infarcts, cutaneous ulcerations and interstitial lung disease. Prophylaxis for PJP should be considered in juvenile myositis patients with these features.

Neurological Complications of Rheumatic Disease.

Rheumatic disease represents a broad spectrum of systemic conditions manifested by multisystem involvement and mediated by autoimmunity and inflammation. Their neurological complications may occur at any point in the disease process and are diagnostically challenging. For years central nervous system (CNS) was considered as a system uniquely protected from effects of the immune system because of the blood-brain barrier. Indeed, under physiological conditions immune access to CNS is tightly regulated. Over the past decade, new scientific discoveries highlighted pathways by which immune and neurological systems interact, including a variety of mechanisms controlling permeability of blood-brain barrier, and specific roles that CD4+ and CD8+ T-lymphocytes play in initiation of specific adaptive immune response to neural specific antigens. This leads to release of proinflammatory cytokines (interleukin 1, interleukin 6, and tumor necrosis factor alpha). In addition, B-cells involved in CNS inflammation produce antibodies against membrane bound and soluble antigens. This article describes specific neurological manifestations of the most common autoimmune rheumatic disorders.