Kawasaki disease triggered by parvovirus infection: an atypical case report of two siblings.

BACKGROUND: There are reports of the familial occurrence of Kawasaki disease but only a few reports described Kawasaki disease in siblings. However, the familial cases were not simultaneous. In these patients the idea of infective agents as trigger must be considered. CASE PRESENTATION: We describe two siblings with atypical presentations of Kawasaki disease; the sister was first diagnosed as having parvovirus infection with anemia and the brother was diagnosed as having myocarditis. The first patient was a 9-month-old Caucasian girl with fever, conjunctivitis, rash, and pharyngitis, and later she had cervical adenopathy, diarrhea and vomiting, leukocytosis, and anemia, which were explained by positive immunoglobulin M against parvovirus. However, coronary artery lesions with aneurysms were documented at day 26 after fever onset. An infusion of intravenous immunoglobulin and high doses of steroids were not efficacious to resolve the coronary lesions. She was treated with anakinra, despite a laboratory test not showing inflammation, with prompt and progressive improvement of coronary lesions. Her 7-year-old Caucasian brother presented vomiting and fever at the same time as she was unwell, which spontaneously resolved after 4 days. Four days later, he again presented with fever with abdominal pain, associated with tachypnea, stasis at the pulmonary bases, tachycardia, gallop rhythm, hypotension, secondary anuria, and hepatomegaly. An echocardiogram revealed a severe hypokinesia, with a severe reduction of the ejection fraction (20%). He had an increase of immunoglobulin M anti-parvovirus, tested for the index case of his sister, confirming the suspicion of viral myocarditis. He received dopamine, dobutamine, furosemide plus steroids, with a progressive increase of the ejection fraction to 50%. However, evaluating his sister's history, the brother showed a myocardial dysfunction secondary to Kawasaki shock syndrome. CONCLUSIONS: We report on familial Kawasaki disease in two siblings which had the same infectious trigger (a documented parvovirus infection). The brother was diagnosed as having post-viral myocarditis. However, in view of the two different and simultaneous evolutions, the girl showed Kawasaki disease with late coronary artery lesions and aneurysms, whereas the brother showed Kawasaki shock syndrome with myocardial dysfunction. We stress the effectiveness of anakinra in non-responder Kawasaki disease and the efficacy on coronary aneurysms.

Interplay between lysosomal, mitochondrial and death receptor pathways during manganese-induced apoptosis in glial cells.

Manganese (Mn) is an essential trace metal which plays a critical role in brain physiology by acting as a cofactor for several enzymes. However, upon overexposure, Mn preferentially accumulates within the basal ganglia leading to the development of a Parkinsonism known as Manganism. Data from our group have proved that Mn induces oxidative stress-mediated apoptosis in astrocytoma C6 cells. In the present study we described how cathepsins impact on different steps of each apoptotic cascade. Evidence obtained demonstrated that Mn generates lysosomal membrane permeabilization (LMP) and cathepsin release. Both cathepsins B (Ca-074 Me) and D (Pepstatin A) inhibitors as well as Bafilomycin A1 prevented caspases-3, -7, -8 and -9 activation, FasL upregulation, Bid cleavage, Δφm disruption and cytochrome c release. Results from in vivo studies showed that intrastriatal Mn injection increased cathepsin D levels from corpus striatum and substantia nigra pars compacta. Our results point to LMP and lysosomal cathepsins as key mediators in the apoptotic process triggered by Mn. These findings highlight the relevance of targeting the lysosomal pathway for Manganism therapy.

The autophagic- lysosomal pathway determines the fate of glial cells under manganese- induced oxidative stress conditions.

Manganese (Mn) overexposure is frequently associated with the development of a neurodegenerative disorder known as Manganism. The Mn-mediated generation of reactive oxygen species (ROS) promotes cellular damage, finally leading to apoptotic cell death in rat astrocytoma C6 cells. In this scenario, the autophagic pathway could play an important role in preventing cytotoxicity. In the present study, we found that Mn induced an increase in the amount and total volume of acidic vesicular organelles (AVOs), a process usually related to the activation of the autophagic pathway. Particularly, the generation of enlarged AVOs was a ROS- dependent event. In this report we demonstrated for the first time that Mn induces autophagy in glial cells. This conclusion emerged from the results obtained employing a battery of autophagy markers: a) the increase in LC3-II expression levels, b) the formation of autophagic vesicles labeled with monodansylcadaverine (MDC) or LC3 and, c) the increase in Beclin 1/ Bcl-2 and Beclin 1/ Bcl-X(L) ratio. Autophagy inhibition employing 3-MA and mAtg5(K130R) resulted in decreased cell viability indicating that this event plays a protective role in Mn- induced cell death. In addition, mitophagy was demonstrated by an increase in LC3 and TOM-20 colocalization. On the other hand, we proposed the occurrence of lysosomal membrane permeabilization (LMP) based in the fact that cathepsins B and D activities are essential for cell death. Both cathepsin B inhibitor (Ca-074 Me) or cathepsin D inhibitor (Pepstatin A) completely prevented Mn- induced cytotoxicity. In addition, low dose of Bafilomycin A1 showed a similar effect, a finding that adds evidence about the lysosomal role in Mn cytotoxicity. Finally, in vivo experiments demonstrated that Mn induces injury and alters LC3 expression levels in rat striatal astrocytes. In summary, our results demonstrated that autophagy is activated to counteract the harmful effect caused by Mn. These data is valuable to be considered in future research concerning Manganism therapies.

Mechanostructure and composition of highly reproducible decellularized liver matrices.

Despite the increasing number of papers on decellularized scaffolds, there is little consensus on the optimum method of decellularizing biological tissue such that the micro-architecture and protein content of the matrix are conserved as far as possible. Focusing on the liver, the aim of this study was therefore to develop a method for the production of well-characterized and reproducible matrices that best preserves the structure and composition of the native extra cellular matrix (ECM). Given the importance of matrix stiffness in regulating cell response, the mechanical properties of the decellularized tissue were also considered. The testing and analysis framework is based on the characterization of decellularized and untreated samples in the same reproducible initial state (i.e., the equilibrium swollen state). Decellularized ECM (dECM) were characterized using biochemical, histological, mechanical and structural analyses to identify the best procedure to ensure complete cell removal while preserving most of the native ECM structure and composition. Using this method, sterile decellularized porcine ECM with highly conserved intra-lobular micro-structure and protein content were obtained in a consistent and reproducible manner using the equilibrium swollen state of tissue or matrix as a reference. A significant reduction in the compressive elastic modulus was observed for liver dECM with respect to native tissue, suggesting a re-examination of design parameters for ECM-mimicking scaffolds for engineering tissues in vitro.