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.

Chronic Thrombocytopenia as the Initial Manifestation of STIM1-Related Disorders.

Pediatric thrombocytopenia has a wide differential diagnosis, and recently, genetic testing to identify its etiology has become more common. We present a case of a 16-year-old boy with a history of chronic moderate thrombocytopenia, who later developed constitutional symptoms and bilateral hand edema with cold exposure. Laboratory evaluation revealed evidence both of inflammation and elevated muscle enzymes. These abnormalities persisted over months. His thrombocytopenia was determined to be immune mediated. Imaging revealed lymphadenopathy and asplenia, and a muscle biopsy was consistent with tubular aggregate myopathy. Ophthalmology evaluation noted photosensitivity, pupillary miosis, and iris hypoplasia. Genetic testing demonstrated a pathogenic variant in STIM1 consistent with autosomal dominant Stormorken syndrome. Our case is novel because of the overlap of phenotypes ascribed to both gain-of-function and loss-of-function pathogenic variants in STIM1, thereby blurring the distinctions between these previously described syndromes. Pediatricians should consider checking muscle enzymes when patients present with thrombocytopenia and arthralgia, myalgia, and/or muscle weakness. Our case highlights the importance of both multidisciplinary care and genetic testing in cases of chronic unexplained thrombocytopenia. By understanding the underlying genetic mechanism to a patient's thrombocytopenia, providers are better equipped to make more precise medical management recommendations.

Patient characteristics associated with response to NSAID monotherapy in children with systemic juvenile idiopathic arthritis.

BACKGROUND: Systemic juvenile idiopathic arthritis (sJIA) is an auto-inflammatory disease characterized by fever, arthritis, and ≥1 of rash, generalized lymphadenopathy, hepato/splenomegaly, and serositis. Non-steroidal anti-inflammatory drugs (NSAIDs) are among the initial treatments of sJIA, but there is currently no evidence indicating which children should undergo a trial of NSAID monotherapy and which should not. Our objective is to identify presentation characteristics which are associated with response and lack of response to a trial of NSAID monotherapy. METHODS: This is a retrospective single-center cohort study of children diagnosed with sJIA from 2000 to 2014. Patient demographics and disease characteristics were investigated to identify predictors of response to NSAID monotherapy. RESULTS: Eighty-seven children were newly diagnosed with sJIA 2000-2014. Thirteen of the 51 children who received NSAID monotherapy achieved clinically inactive disease (CID) without other medications. Age at presentation (≤8 years old), initial joint count (≤5), and C-reactive protein (CRP) (≤13 mg/dL) at diagnosis were associated with achievement of CID on NSAIDs alone. Physicians were less likely to trial NSAID monotherapy if the patient had either serositis or macrophage activation syndrome (MAS) at diagnosis. Ultimate achievement of CID and time to CID were not significantly affected by whether the patient received a trial of NSAID monotherapy. CONCLUSIONS: While a subset of children with sJIA can achieve CID with NSAID monotherapy, we recommend against a trial in patients who are >8 years old, with >5 joints involved, or with CRP > 13 mg/dL. Patients who undergo a trial of NSAID monotherapy should follow up within 2-4 weeks to evaluate for possible need for drug escalation. Clinical trials are necessary to confirm these findings.