Heterophilic antibodies in sera from individuals without loxoscelism cross-react with phospholipase D from the venom of Loxosceles and Sicarius spiders

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)

Heterophilic antibodies in sera from individuals without loxoscelism cross-react with phospholipase D from the venom of Loxosceles and Sicarius spiders

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.

Antibody Status in Children with Steroid-Sensitive Nephrotic Syndrome

PURPOSE: The pathophysiology of hypogammaglobulinemia in nephrotic syndrome (NS) remains unknown. We evaluated the differences in the distribution of anti-bacterial antibodies and anti-viral antibodies, and those of immune antibodies and natural antibodies in steroid-sensitive NS. MATERIALS AND METHODS: We examined the antibody status of 18 children who had routine vaccinations. The levels of immnunoglobulin G (IgG), the IgG subclasses, and the antibodies induced by vaccinations such as diphtheria-pertussis-tetanus and measles-mumpsrubella were analyzed in children with steroid-sensitive NS. RESULTS: There was a positive correlation between the albumin and IgG values (r = 0.6, p < 0.01), and the four IgG subclasses were all evenly depressed in the nephrotic children during the acute stage of the disease. The antibodies induced by bacterial antigens were depressed and the seropositivity of anti-viral antibodies tended to be lower than those of age-matched control children during the acute stage. The depressed immune antibody status recovered rapidly in the remission stage of NS, despite corticosteroid treatment. CONCLUSIONS: IgG levels correlated positively with albumin levels, and all antibodies, including immune and natural antibodies, were depressed in the acute stage of NS. Our results suggest that hypogammaglobulinaemia in NS may be associated with intravascular homeostasis of oncotic pressure.

Natural antibodies in paracoccidioidomycosis

Recent attention has been focused on the natural antibodies as a component of natural immunity and as integral part of the idiotypic network. However, their functional role in different infections has rarely been studied. This work was undertaken to investigate the presence of natural antibodies in paracoccidioidomycosis (PCM). In addition, we analyzed anti-P. brasiliensis antibodies and their distribution in IgG subclasses in order to acquire better knowledge about the humoral immune response in this mycosis. Our findings show that the natural antibody response is not very much increased in PCM when compared with other parasite infections and this response is restricted to a few specificities, suggesting that P. brasiliensis moderately triggers CD5+ B cells. The anti-actin antibody was the main antibody specificity found in PCM. Specific antibodies to P. brasiliensis were mainly found in the IgG1 subclass in chronic patients of PCM.

Recente atenção tem sido dada aos anticorpos naturais como componentes da imunidade natural e como parte integrante da rede idiotípica. Todavia, seu papel funcional em diferentes infecções tem, raramente, sido estudado. O objetivo deste trabalho foi investigar a presença de anticorpos naturais na paracoccidioidomicose (PCM). Em adição, analisamos os anticorpos específicos anti-P. brasiliensis e sua distribuição em subclasses a fim de adquirir mais conhecimento sobre a resposta imune humoral nesta micose. Nossos achados mostram que a resposta de anticorpos naturais não é acentuada na PCM quando comparada com outras infecções por parasitas e, é restrita a poucas especificidades, sugerindo que o P. brasiliensis estimula moderadamente as células B CD5+. O anticorpo anti-actina foi a principal especificidade encontrada na PCM. Os anticorpos especificos para P. brasiliensis, nos pacientes crônicos, eram, principalmente, da subclasse IgG1.

A Study of the Anti-porcine Endothelial Immunoglobulin and Complement in the Sera of End-stage Renal Failure Patients and End- stage Liver Failure Patients / 대한이식학회지

PURPOSE: Shortage of donor organs is one of the major barriers of clinical organ transplantation. To overcome the shortage, a huge amount of research into xenotransplantation has been done worldwide. The major problem in xenotransplantation is hyperacute rejection, a rapid and violent rejection that damages the graft within minutes or hours. Hyperacute rejection is mediated by the components of natural immunity, most notably natural antibodies and complements. METHODS: The aim of this study is to explore the quantitative amounts of the natural antibodies and complements in the sera of patential recipients with respect to their diseases. The samples of blood from the 10 patients with end stage renal or liver disease were obtained for the assay of natural xenoreactive antibodies. Natural anti-porcine endothelial antibodies (IgM and IgG) were measured by ELISA with porcine aortic endothelial cells in culture as targets. Quantitative analysis of C3 was also done with the ELISA with porcine endothelial cell in culture. RESULTS: Optical densities measured with the ELISA for IgM or IgG natural antibodies in the blood from the different three groups (healthy volunteer, renal failure patients, and liver failure patients) to cultured porcine aortic endothelial cells were not statistically (P>0.05) different among the three groups. Moreover, those for complement (C3) to porcine endothelial cells were not statistically (P>0.05) different among the groups. CONCLUSION: Further efforts should be made toward modifying the technique for removal of specific natural antibodies and complements for the successful xenotransplantation regardless the disease entities of potential recipient candidates.