Acute Rheumatic Fever and Poststreptococcal Reactive Arthritis

Persistent Valvular Regurgitation After Acute Rheumatic Fever: Early Predictors of Long Term Outcomes in a Pediatric Retrospective Cohort

Describe the echocardiographic evolution of valvular regurgitation in patients with rheumatic carditis (RC) and to establish which features may predict long-term outcome, in the absence of acute rheumatic fever (ARF) relapse. Retrospective cohort study. 123 patients with confirmed RC, diagnosed at Turin Children's Hospital between 2010 and 2019. We reviewed the echocardiographic images recorded at diagnosis, after 6-8 weeks, after 6 months, then yearly, to assess which predictors at diagnosis are associated with the degree of improvement at 6 months. Secondly, we tested which variables predict the regression of pathological regurgitation of mitral (MV) or aortic valve (AV) during follow-up. At onset, 90.2% patients had MV regurgitation while 42.3% had AV involvement. 115 (93.5%) patients were treated with steroids and 70.8% experienced a downgrading of RC after 6 months. Steroids were associated with better outcomes at six months (p = 0.01). During follow-up (median 56.1 months), MV improved in 58.6% patients, AV in 46.2%. At multivariate analysis, erythrocyte sedimentation rate (ESR) was positively associated with regression of MV regurgitation (OR 1.02, p = 0.02), while higher degree of carditis at onset was negatively associated (OR 0.04, p < 0.01). Conversely, regression of AV regurgitation was more frequent in patients with bi-valvular involvement (OR 20.5, p = 0.03) and in absence of murmur at onset (OR 0.04, p = 0.01). This study indicates that valvular regurgitation improves overtime if there are no ARF recurrences during follow-up, especially when the MV is involved and in patients treated with steroids.

Acute rheumatic fever associated with tenosynovitis and a unique cytokine profile

Acute rheumatic fever (ARF), caused by group A β-hemolytic streptococcus infection, is characterized by inflammation affecting several organs. There are few reports on magnetic resonance imaging (MRI) findings in patients with ARF. An 8-year-old Japanese boy presented with a prolonged fever of unknown cause and swelling of his right hand. MRI of his hand revealed tenosynovitis. Migratory arthritis and erythema marginatum appeared following the hand swelling. We diagnosed him as having ARF based on the clinical course and serological testing for group A β-hemolytic streptococcus. His serum interleukin-18 levels were lower than those typically seen in cases of systemic juvenile idiopathic arthritis (sJIA). After treatment with naproxen, his symptoms improved immediately. In conclusion, MRI findings of tenosynovitis may be useful for the diagnosis of not only sJIA but also ARF in patients presenting with a fever of unknown origin. Subsequently, the diagnosis of ARF can be confirmed with specific serological tests. Serum interleukin-18 levels may be helpful in the differential diagnosis of ARF and sJIA. Although ARF is rare in developed countries, including Japan, early diagnosis and appropriate treatment are important to prevent rheumatic heart disease.