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
La determinación de tiroglobulina sérica se emplea, sobre todo, como marcador tumoral en el seguimiento posoperatorio de pacientes con cáncer diferenciado del tiroides. Lamentablemente, los métodos de tiroglobulina sérica presentan gran variabilidad en sus cualidades analíticas y padecen problemas técnicos que repercuten sobre la utilidad clínica de esta prueba. Para cuantificar tiroglobulina sérica se emplean 2 tecnologías diferentes: los iniciales radioinmunoensayos competitivos y los mßs recientes métodos inmunométricos no competitivos. Estos últimos son más propensos a sufrir las interferencias provocadas por la presencia de autoanticuerpos tiroglobulina y anticuerpos heterofílicos, a pesar de brindar los beneficios técnicos relativos al uso de reactivos no isotópicos, menor volumen de muestra, tiempos de incubación más cortos, así como mejor sensibilidad y facilidad de automatización. Resulta esencial que los clínicos conozcan y comprendan las limitaciones técnicas inherentes a la determinación de tiroglobulina sérica y su repercusión sobre la utilidad clínica de esta, con la finalidad de hacer un uso efectivo y eficiente de esta prueba en el seguimiento posoperatorio de pacientes con cáncer diferenciado del tiroides(AU)
The serum thyroglobulin assessment is used mainly as tumor marker during the postoperative follow-up of patients presenting with thyroid differentiated cancer. Progressively, the serum thyroglobulin methods have much variability in its analytical qualities and also have technical problems affecting on the technical usefulness of this test. To quantify the serum thyroglobulin we used two different technologies: the initial competitive radioimmunoassays and the most recent non competitive inmunometrical methods. These latter are more prone to have interferences provoked by presence of thyroglobulin antibodies and heterophilic antibodies despite to offer technical beneficial relative to use of non-isotopic reagents, a lower sample volume, shorter incubation times, as well as a better sensitivity and feasibility of automation. It is essential that clinicians know and understand the technical limitations inherent of serum thyroglobulin assessment and its repercussion on its clinical usefulness to an effective and efficient use of this test during the postoperative follow-up of patients presenting thyroid differential cancer(AU)