ABSTRACT
Loxoscelism is a severe human envenomation caused by Loxosceles spider venom. To the best of our knowledge, no study has evaluated the presence of antibodies against Loxosceles venom in loxoscelism patients without treatment with antivenom immunotherapy. We perform a comparative analysis for the presence of antibodies capable of recognizing Loxosceles venom in a group of patients diagnosed with loxoscelism and in a group of people without loxoscelism. Methods The detection of L. laeta venom, Sicarius venom and recombinant phospholipases D from Loxosceles (PLDs) in sera from people with loxoscelism (Group 1) and from healthy people with no history of loxoscelism (Group 2) was evaluated using immuno-dot blot, indirect ELISA, and Western blot. Results We found naturally heterophilic antibodies (IgG-type) in people without contact with Loxosceles spiders or any clinical history of loxoscelism. Either serum pools or single sera from Group 1 and Group 2 analyzed by dot blot tested positive for L. laeta venom. Indirect ELISA for venom recognition showed titles of 1:320 for Group 1 sera and 1:160 for Group 2 sera. Total IgG quantification showed no difference in sera from both groups. Pooled sera and purified IgG from sera of both groups revealed venom proteins between 25 and 32 kDa and the recombinant phospholipase D isoform 1 (rLlPLD1), specifically. Moreover, heterophile antibodies cross-react with PLDs from other Loxosceles species and the venom of Sicarius spider. Conclusions People without contact with the spider venom produced heterophilic antibodies capable of generating a cross-reaction against the venom of L. laeta and Sicarius spiders. Their presence and possible interference should be considered in the development of immunoassays for Loxosceles venom detection.(AU)
Subject(s)
Humans , Male , Female , Adolescent , Adult , Middle Aged , Phospholipase D/isolation & purification , Spider Venoms/toxicity , Antibodies, Heterophile/blood , Antivenins/therapeutic use , Enzyme-Linked Immunosorbent Assay/methods , Immunoblotting/methodsABSTRACT
Background Loxoscelism is a severe human envenomation caused by Loxosceles spider venom. To the best of our knowledge, no study has evaluated the presence of antibodies against Loxosceles venom in loxoscelism patients without treatment with antivenom immunotherapy. We perform a comparative analysis for the presence of antibodies capable of recognizing Loxosceles venom in a group of patients diagnosed with loxoscelism and in a group of people without loxoscelism. Methods The detection of L. laeta venom, Sicarius venom and recombinant phospholipases D from Loxosceles (PLDs) in sera from people with loxoscelism (Group 1) and from healthy people with no history of loxoscelism (Group 2) was evaluated using immuno-dot blot, indirect ELISA, and Western blot. Results We found naturally heterophilic antibodies (IgG-type) in people without contact with Loxosceles spiders or any clinical history of loxoscelism. Either serum pools or single sera from Group 1 and Group 2 analyzed by dot blot tested positive for L. laeta venom. Indirect ELISA for venom recognition showed titles of 1:320 for Group 1 sera and 1:160 for Group 2 sera. Total IgG quantification showed no difference in sera from both groups. Pooled sera and purified IgG from sera of both groups revealed venom proteins between 25 and 32 kDa and the recombinant phospholipase D isoform 1 (rLlPLD1), specifically. Moreover, heterophile antibodies cross-react with PLDs from other Loxosceles species and the venom of Sicarius spider. Conclusions People without contact with the spider venom produced heterophilic antibodies capable of generating a cross-reaction against the venom of L. laeta and Sicarius spiders. Their presence and possible interference should be considered in the development of immunoassays for Loxosceles venom detection.
Subject(s)
Antibodies, Heterophile/analysis , Phospholipase D/immunology , Spider Venoms/immunology , Spider Bites/complicationsABSTRACT
Spiders of the genus Loxosceles have a wide world distribution. In Chile, the brown recluse spider Loxosceles laeta, commonly called the "corner spider", is one of the species which causes the clinical syndrome known as loxoscelism, poisoning by the accidental bite of this arachnid. Loxoscelism is characterized by dermonecrotic lesions (cutaneous loxoscelism), which in more severe cases (systemic loxoscelism) may be accompanied by intravascular hemolysis of erythrocytes and renal insufficiency with a high associated mortality. Treatment requires the precocious application of anti-venom, along with complementary measures based on the use of antihistamines, corticoids and antibiotics. The diagnosis, which currently is eminently clinical, should be accompanied by the identification of the spider when possible, due to the lack of diagnostic methods of rapid response applicable at the level of emergency clinics. The introduction of new tools based on recombinant proteins of highly immunogenic components present in the venom is a recently explored alternative. Preventive methods based on avoidance of contact with the spider continue to be the principal mechanism to avoid an endemic pathology with high risk of death in our region. The objective of this revision is to bring up to date fundamental aspects of loxoscelism, especially its epidemiology, diagnosis and clinical treatment.
Las arañas del género Laxosceles, tienen una amplia distribución mundial. En Chile, Laxosceles laeta (comúnmente conocida como araña de los rincones) es una de las especies causante del cuadro clínico conocido como loxoscelismo, envenenamiento por la mordedura de este arácnido por accidente. El loxoscelismo se caracteriza por lesiones dermonecróticas (loxoscelismo cutáneo), que en los casos más graves (loxoscelismo sistemáticos), se puede acompañar con hemólisis intravascular de los eritrocitos e insuficiencia renal con elevada mortalidad asociada. El tratamiento requiere la aplicación precoz del antisuero, junto a mediadas complementarias basada con el uso del antihistamínicos, corticoides y antibióticos. El diagnóstico, en la actualidad eminentemente clínico, debe ser acompañado por la identificación de los ejemplares, cuando es posible, ante la falta de métodos diagnóstico de respuesta precoz aplicable a nivel asistencial de urgencia. La introducción de nuevas herramientas basadas en proteínas recombinantes de componentes altamente inmunogénicos presentes en el veneno, es una alternativa explorada recientemente. Las medidas de prevención basadas en evitar el contacto con la araña, sigue siendo los principales mecanismos para evitar una patología endémica y con elevado riesgo de muerte en nuestra región. El objetivo de la presente revisión es actualizar aspectos fundamentales del loxoscelismo, especialmente sobre su epidemiología, clínica, diagnóstico y tratamiento.
Subject(s)
Humans , Spider Bites/diagnosis , Spider Bites/physiopathology , Spider Bites/therapy , Spider Bites/epidemiologyABSTRACT
Background: Loxoscelism is a severe reaction to the bite of the spider Loxosceles laeta. In recent years, a paint with repellent properties has been promoted in the commerce. However, there are no reports of experiments evaluating its effectiveness. Aim: To evaluate experimentally the repellent properties of a paint against Loxosceles laeta. Material and methods: Males, females and nymphs of L laeta were deposited in cockpits that allow the free displacement of the spider. Half of the cockpit was covered with repellent paint. Daily observations during one week, determined how frequently the spiders occupied the space covered with repellent paint. The experiments were run in triplicate. Results: No statisticaldifferences in the occupancy of spaces covered with repellent paint or not covered with it were observed for nymphs (87% and 67%, respectively), males (72% and 77%, respectively) orfemales (91% and 84%, respectively). Conclusions: The tested paint does not have a repellent action against the spider Loxosceles laeta.