RESUMO
AIM: To develop and validate an algorithm to rapidly distinguish transient synovitis (TS) of the hip from differential diagnoses without additional tests. METHODS: This retrospective cohort study included all children admitted for non-traumatic limping in the emergency department at Lille University-Hospital between 2016 and 2020. The gold standard was a definitive diagnosis at follow-up visit. All variables associated with acute limping in children were analysed in univariate and multivariable analyses. An algorithm was then developed using recursive partitioning and validated internally on a subset of patients. RESULTS: There were 995 patients included (mean age 5.3 years; males 63%); 337 had a TS including 210 confirmed at follow-up visit and 354 another diagnosis. After multivariable analysis, the relevant variables for distinguishing between TS and differential diagnoses were: age 3-10 years, absence of fever, absence of local inflammation, sudden onset of limping on awakening. An algorithm combining these variables was developed (n = 297) and validated internally (n = 175) for children >12 months with limping for ≤10 days, with a specificity of 98.2% and a positive likelihood ratio of 19.6. No serious differential diagnoses were missed. CONCLUSION: Use of this algorithm enables the diagnosis of TS without additional tests and without missing serious differential diagnoses.
Assuntos
Algoritmos , Sinovite , Humanos , Masculino , Pré-Escolar , Sinovite/diagnóstico , Estudos Retrospectivos , Feminino , Criança , Lactente , Articulação do Quadril , Diagnóstico Diferencial , Estudos de CoortesRESUMO
Heterozygous missense mutations in coatomer protein subunit α, COPA, cause a syndrome overlapping clinically with type I IFN-mediated disease due to gain-of-function in STING, a key adaptor of IFN signaling. Recently, increased levels of IFN-stimulated genes (ISGs) were described in COPA syndrome. However, the link between COPA mutations and IFN signaling is unknown. We observed elevated levels of ISGs and IFN-α in blood of symptomatic COPA patients. In vitro, both overexpression of mutant COPA and silencing of COPA induced STING-dependent IFN signaling. We detected an interaction between COPA and STING, and mutant COPA was associated with an accumulation of ER-resident STING at the Golgi. Given the known role of the coatomer protein complex I, we speculate that loss of COPA function leads to enhanced type I IFN signaling due to a failure of Golgi-to-ER STING retrieval. These data highlight the importance of the ER-Golgi axis in the control of autoinflammation and inform therapeutic strategies in COPA syndrome.