Bilateral sterile subdural effusion in Kawasaki disease-A case report.

Kawasaki disease is an acute febrile condition that causes a self-limiting medium vessel systemic vasculitis and whose pathophysiological pathways are still not completely understood. Coronary arteries are the most affected, but inflammation can develop in all medium-sized arteries, with various organs and tissues being involved. Kawasaki disease-related neurological involvement varies in terms of clinical expression and severity. Herein, we describe an unusual neurological complication of Kawasaki disease in a 5-year-old girl. The progression of the disease was biphasic. Kawasaki disease was diagnosed on the 8th day after symptoms onset and treated by intravenous immunoglobulins, with prompt clinical regression but a less favorable biological response (persistent inflammation with hypoalbuminemia). Two weeks later, headaches and lethargy developed, and a bilateral subdural collection was identified on cerebral imaging. Subsequently, her progress was uneventful, with no residual coronary abnormalities and complete resorption of the subdural collection. Bilateral subdural collection, exceptionally reported, could be discussed as a clinical expression of systemic inflammatory vasculitis that characterizes Kawasaki disease.

Polyclonal expansion of TCR Vbeta 21.3+ CD4+ and CD8+ T cells is a hallmark of Multisystem Inflammatory Syndrome in Children.

Multiple Inflammatory Syndrome in Children (MIS-C) is a delayed and severe complication of SARS-CoV-2 infection that strikes previously healthy children. As MIS-C combines clinical features of Kawasaki disease and Toxic Shock Syndrome (TSS), we aimed to compare the immunological profile of pediatric patients with these different conditions. We analyzed blood cytokine expression, and the T cell repertoire and phenotype in 36 MIS-C cases, which were compared to 16 KD, 58 TSS, and 42 COVID-19 cases. We observed an increase of serum inflammatory cytokines (IL-6, IL-10, IL-18, TNF-α, IFNγ, CD25s, MCP1, IL-1RA) in MIS-C, TSS and KD, contrasting with low expression of HLA-DR in monocytes. We detected a specific expansion of activated T cells expressing the Vß21.3 T cell receptor ß chain variable region in both CD4 and CD8 subsets in 75% of MIS-C patients and not in any patient with TSS, KD, or acute COVID-19; this correlated with the cytokine storm detected. The T cell repertoire returned to baseline within weeks after MIS-C resolution. Vß21.3+ T cells from MIS-C patients expressed high levels of HLA-DR, CD38 and CX3CR1 but had weak responses to SARS-CoV-2 peptides in vitro. Consistently, the T cell expansion was not associated with specific classical HLA alleles. Thus, our data suggested that MIS-C is characterized by a polyclonal Vß21.3 T cell expansion not directed against SARS-CoV-2 antigenic peptides, which is not seen in KD, TSS and acute COVID-19.

Case report: Staphylococcus aureus endocarditis in 2 premature newborns.

RATIONALE: Neonatal infectious endocarditis (IE) in a healthy heart is rare. The infectious agents most frequently found in newborns are Staphylococcus aureus and fungi. Infection at the site of central intravenous catheter is generally thought to be the cause of this pathology. PATIENT CONCERNS: We present 2 cases of premature newborns whose condition is evolving positively. They presented S aureus endocarditis during their first week of life. DIAGNOSIS: Modified Duke diagnostic criteria-from clinical, echocardiogram and microbiological findings-based on those used for adults, can be used for children and newborns, but the very low prevalence of neonatal IE often delays diagnosis. Diagnosis on the basis of transthoracic heart ultrasound requires an extension report, given the very high embolic risk. INTERVENTION: In the large majority of cases, long-term antibiotic therapy efficaciously treats the infection, although sometimes surgery is necessary. These 2 newborns needed only antibiotic therapy. OUTCOME: Despite the various complications, especially embolic, these 2 children are followed and are doing well. LESSONS: Long-term pediatric heart monitoring combined with prophylactic antibiotics are essential, according to the European Society of Cardiology guidelines.

First Case of Q Fever Endocarditis Involving the Melody® Transcatheter Pulmonary Valve in an Afebrile Child.

In this article we report the first case of Q fever endocarditis in a 13 years old child with a percutaneous pulmonary Melody® valve. The patient had a new onset of Melody valve dysfunction associated with the combination of hepatosplenomegaly and pancytopenia but was afebrile. Although blood cultures were negative, we have further investigated in the direction of infective endocarditis by performing PCR detection and the serology of C. burnetii which were positive. A combination antibiotic therapy with doxycycline and hydroxychloroquine was started with good clinical evolution. Our case emphasizes the fact that any Melody valvular dysfuntion should be considered as a potential infective endocarditis despite the absence of typical bacterial features.