Accidente Lonómico: Reporte de dos casos / Lonomic accident: Report of two cases

Resumen Introducción: dentro de los insectos del orden lepidóptero, la familia Saturniidae tiene más de 2.400 especies, allí se encuentran Hylesia y Lonomia. Objetivo: presentar dos casos de pacientes con accidente lonómico, el manejo y desenlace para reconocer la importancia de estos eventos en las regiones silvestres de la Orinoquia colombiana. Casos clínicos: paciente de 8 años proveniente de área rural quien refería contacto en región palmar de mano derecha con gusanos quién 48 horas después de dicho contacto presentó equimosis en extremidades, flictena sangrante en talón derecho, cefalea, escalofríos y artralgias, además se evidenciaron tiempos de coagulación prolongados. Paciente de 13 años de características similares a las del caso previamente descrito sin presentar manifestaciones clínicas, pero que presentaba tiempos de coagulación prolongados. Se consideró que cursaba con accidente lonómico por lo que se aplicaron 5 ampollas de suero antilonómico polivalente a cada una sin registrar reacciones adversas. En ambos casos cursaron con evolución clínica adecuada con disminución a rangos de seguridad de tiempos de coagulación. Conclusiones: el veneno lonómico actúa en la cascada de coagulación produciendo manifestaciones hemorrágicas de gravedad variable. El suero antilonómico es el único tratamiento eficaz, a pesar de estar disponible desde hace más de 20 años en Brasil hay un 5% de progresión a síndromes hemorrágicos severos y un 1.5 a 2% de mortalidad. A pesar de tener gran relevancia clínica en las Américas existe subregistro, es importante conocer sus manifestaciones y el manejo para así poder evitar complicaciones mortales.

Abstract Background: among the insects of the order Lepidoptera, the family Saturniidae has more than 2,400 species, there are Hylesia and Lonomia. Objective: to present two cases of patients with lonomic accident, the management and outcome to recognize the importance of these events in the wild regions of the Colombian orinoquia. Clinical case: an 8-year-old patient from a rural area who refers to contact in the palmar region of the right hand with worms for more than 48 hours, presents ecchymosis in the extremities, bleeding flictena in the right heel, headache, chills and arthralgias. Clotting times are performed which are prolonged. A 13-year-old patient who also referred contact without presenting clinical manifestations but presenting prolonged clotting times. They are considered to occur due to a lonomic accident, so 5 ampoules of polyvalent antilonomic serum are administered to each one without registering adverse reactions. They have an adequate clinical evolution with a decrease in the safe ranges of clotting times. Conclusions: the lonomic venom acts in the coagulation cascade producing hemorrhagic manifestations of variable severity. Antilonomic serum is the only effective treatment, despite being available for more than 20 years in Brazil, there is a 5% progression to severe hemorrhagic syndromes and 1.5 to 2% mortality. Despite being of great clinical relevance in the Americas, there is an underreporting, it is important to know its manifestations and management in order to avoid fatal complications.

Lonomia obliqua Venom Induces NF-κB Activation and a Pro-Inflammatory Profile in THP-1-Derived Macrophage.

Envenomation caused by contact with Lonomia obliqua bristles is characterized by pain, an intense systemic proinflammatory reaction and disturbances in the coagulation cascade that can cause severe clinical manifestations and death. However, the role of immune system components in these effects is still poorly understood. In this study, we evaluated the cytotoxic effect of L. obliqua venom on THP-1-derived macrophages and its ability to modulate inflammatory markers, as well as the cytokine and chemokine release profile. Our results show that L. obliqua venom is able to directly exert a potent pro-inflammatory reaction in macrophages, characterized by the activation of the NF-κB transcription factor pathway, the expression of CD80 and CD83, and the release of pro-inflammatory mediators such as TNF-α, IL-1ß, IL-6, IL-8 and CXCL10. These results suggest that macrophages can play an important role during the orchestration of the inflammatory response present in envenomation caused by Lonomia obliqua caterpillars.

Lonomia obliqua venom induces NF-κB activation and a pro-inflammatory profile in THP-1-derived macrophage

Envenomation caused by contact with Lonomia obliqua bristles is characterized by pain, an intense systemic proinflammatory reaction and disturbances in the coagulation cascade that can cause severe clinical manifestations and death. However, the role of immune system components in these effects is still poorly understood. In this study, we evaluated the cytotoxic effect of L. obliqua venom on THP-1-derived macrophages and its ability to modulate inflammatory markers, as well as the cytokine and chemokine release profile. Our results show that L. obliqua venom is able to directly exert a potent pro-inflammatory reaction in macrophages, characterized by the activation of the NF-κB transcription factor pathway, the expression of CD80 and CD83, and the release of pro-inflammatory mediators such as TNF-α, IL-1β, IL-6, IL-8 and CXCL10. These results suggest that macrophages can play an important role during the orchestration of the inflammatory response present in envenomation caused by Lonomia obliqua caterpillars.

Effects of Lonomia obliqua Venom on Vascular Smooth Muscle Cells: Contribution of NADPH Oxidase-Derived Reactive Oxygen Species.

Envenomation caused by human contact with the caterpillar Lonomia is characterized by deleterious effects on coagulation and patency of blood vessels. The cellular effects induced by Lonomia obliqua venom highlights its capacity to activate endothelial cells, leading to a proinflammatory phenotype. Having more knowledge about the mechanisms involved in envenomation may contribute to better treatment. We aimed to evaluate the effects of Lonomia obliqua caterpillar bristle extract (LOCBE) on vascular smooth muscle cells (VSMC). We observed that LOCBE induced VSMC migration, which was preceded by alterations in actin cytoskeleton dynamics and Focal Adhesion Kinase activation. LOCBE also induced Extracellular Signal-Regulated Kinase (ERK) phosphorylation in VSMC, and the inhibition of this pathway impaired cell proliferation. Stimulation of VSMC with LOCBE triggered reactive oxygen species (ROS) production through the activation of NADPH oxidase. The rapid increase in these ROS further induced mitochondrial ROS production, however only NADPH oxidase-derived ROS were involved in ERK activation in VSMC. We that demonstrated the chemotactic and proliferative effects of LOCBE on VSMC were dependent on ROS production, mainly through NADPH oxidase. Together, the data show that Lonomia obliqua venom can interact with and activate VSMC. These effects rely on ROS production, suggesting new potential targets for treatment against vascular damage during envenomation.

Hemostatic disorders induced by skin contact with Lonomia obliqua (Lepidoptera, Saturniidae) caterpillars

ABSTRACT Patients envenomed by Lonomia sp caterpillars initially experience a mild burning pain, headache, nausea, vomiting, and skin and mucosal hemorrhages. Some patients can rapidly progress to a severe coagulopathy that presents as visceral or intracerebral hemorrhaging. We studied the hemostatic alterations that occurred in 14 patients who were envenomed by Lonomia obliqua in Southern Brazil and presented at the Hospital São Vicente de Paulo (Passo Fundo, RS), Brazil during the summers of 1993 and 1994 when Lonomia antivenom was not yet available for treatment. The patients were classified into to 4 clinical groups: 0 (two patients), I (eight patients), II (two patients), and III (two patients). The patients were admitted to the hospital between 4 hours and five days after contact with the caterpillars. In this study, the coagulation parameters of the patients were followed up for up to 172 hours after the accidents. The patients received no treatment with the exceptions of two patients who received blood transfusions and antifibrinolytic treatment. The observed abnormalities related to blood coagulation and fibrinolytic factors were similar regardless of the severity of the bleeding symptoms. These findings suggest that alterations in hemostatic parameters without thrombocytopenia are not predictors of the seriousness of such accidents. Thus, consumptive disorder and reactive fibrinolysis are not proportional to mild coagulopathy. Furthermore, these patients recovered. The hemostatic parameters of most of the patients normalized between 96 and 120 h after the accident.

The urticating apparatus in the caterpillar of Lonomia obliqua (Lepidoptera: Saturniidae).

The presence of specialized cells for venom production in the Lonomia obliqua caterpillar has long been a controversial topic. In this study, we identify a cell inside the spine that specializes in the production of toxins. Our histological study showed that this glandular cell was inserted at the subapical region of the spine, in a constricted region like a ring. This cell type was not observed in all spines of the scolus. The constricted region of the spine observed by scanning electron microscopy displayed a circular groove in which the apical portion of the spine fits perfectly; however, some spines in the same scolus lacked this groove. After breaking off the spine at the most apical region, a small drop of orange or green liquid was observed to flow from its tip. These secretions were analysed by MALDI-ToF and found to possess biochemically different compositions. The green secretion demonstrated greater similarity to the haemolymph of the caterpillar than the orange secretion. Based on our findings, the spines with a groove probably contain the venom glands and produce an orange secretion. However, it is also possible that both secretions play an important role in envenoming because all spines in contact with the skin of the accidental victim should break regardless of whether they are present in a groove.

Discovery of a new antiviral protein isolated Lonomia obliqua analysed by bioinformatics and real-time approaches.

This study presents a new recombinant protein that acts as a powerful antiviral (rAVLO-recombinant Antiviral protein of Lonomia obliqua). It was able to reduce the replication by 10(6) fold for herpes virus and by 10(4) fold for rubella virus. RT-PCR of viral RNA rAVLO treated infected cells also showed similar rate of inhibition in replication. The analysis of this protein by bioinformatics suggests that this protein is globular, secreted with a signal peptide and has the ability to bind to MHC class I. It was found that there are several protein binding sites with various HLA and a prevalence of α-helices in the N-terminal region (overall classified as a α/ß protein type). BLAST similarity sequence search for corresponding cDNA did not reveal a similar sequence in Genbank, suggesting that it is from a novel protein family. In this study we have observed that this recombinant protein and hemolymph has a potent antiviral action. This protein was produced in a baculovirus/Sf-9 system. Therefore, these analyses suggest that this novel polypeptide is a candidate as a broad spectrum antiviral.

Moléculas biologicamente ativas da hemolinfa de pupas de Lonomia obliqua

Os insetos formam um grupo grande e diverso de animais. Eles vivem em quase todos os ecossistemas do planeta e essa ampla distribuição tem estimulado a pesquisa por moléculas bioativas entre eles. Vários estudos têm sido realizados demonstrando a presença de substâncias farmacologicamente ativas na hemolinfa dos insetos. A Lonomia obliqua é um inseto de importância médica, pois na sua fase larval possui cerdas urticantes com toxina que causa efeitos hemorrágicos. O veneno da Lonomia é bastante estudado, sendo que muitos dos seus componentes foram isolados e caracterizados. Na hemolinfa da L. obliqua já foram identificadas algumas moléculas como a lonofibrase, que tem ação fibrinogenolítica, e uma proteína de alto peso molecular que estimula a produção de proteínas recombinantes...