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Development of a sensitive enzyme immunoassay for measuring taipan venom in serum.
Toxicon 2010; 55(8):1510-8T

Abstract

The detection and measurement of snake venom in blood is important for confirming snake identification, determining when sufficient antivenom has been given, detecting recurrence of envenoming, and in forensic investigation. Venom enzyme immunoassays (EIA) have had persistent problems with poor sensitivity and high background absorbance leading to false positive results. This is particularly problematic with Australasian snakes where small amounts of highly potent venom are injected, resulting in low concentrations being associated with severe clinical effects. We aimed to develop a venom EIA with a limit of detection (LoD) sufficient to accurately distinguish mild envenoming from background absorbance at picogram concentrations of venom in blood. Serum samples were obtained from patients with taipan bites (Oxyuranus spp.) before and after antivenom, and from rats given known venom doses. A sandwich EIA was developed using biotinylated rabbit anti-snake venom antibodies for detection. For low venom concentrations (i.e. <1 ng/mL) the assay was done before and after addition of antivenom to the sample (antivenom difference method). The LoD was 0.15 ng/mL for the standard assay and 0.1 ng/mL for the antivenom difference method. In 11 pre-antivenom samples the median venom concentration was 10 ng/mL (Range: 0.3-3212 ng/mL). In four patients with incomplete venom-induced consumption coagulopathy the median venom concentration was 2.4 ng/mL compared to 30 ng/mL in seven patients with complete venom-induced consumption coagulopathy. No venom was detected in any post-antivenom sample and the median antivenom dose prior to this first post-antivenom sample was 1.5 vials (1-3 vials), including 7 patients administered only 1 vial. In rats the assay distinguished a 3-fold difference in venom dose administered and there was small inter-individual variability. There was small but measurable cross-reactivity with black snake (Pseudechis), tiger snake (Notechis) and rough-scale snake (Tropidechis carinatus) venoms with the assay for low venom concentrations (<1 ng/mL). The use of biotinylation and the antivenom difference method in venom EIA produces a highly sensitive assay that will be useful for determining antivenom dose, forensic and clinical diagnosis.

Authors+Show Affiliations

Emergency Department, Gold Coast Hospital, Queensland, Australia.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

20223258

Citation

Kulawickrama, S, et al. "Development of a Sensitive Enzyme Immunoassay for Measuring Taipan Venom in Serum." Toxicon : Official Journal of the International Society On Toxinology, vol. 55, no. 8, 2010, pp. 1510-8.
Kulawickrama S, O'Leary MA, Hodgson WC, et al. Development of a sensitive enzyme immunoassay for measuring taipan venom in serum. Toxicon. 2010;55(8):1510-8.
Kulawickrama, S., O'Leary, M. A., Hodgson, W. C., Brown, S. G., Jacoby, T., Davern, K., & Isbister, G. K. (2010). Development of a sensitive enzyme immunoassay for measuring taipan venom in serum. Toxicon : Official Journal of the International Society On Toxinology, 55(8), pp. 1510-8. doi:10.1016/j.toxicon.2010.03.003.
Kulawickrama S, et al. Development of a Sensitive Enzyme Immunoassay for Measuring Taipan Venom in Serum. Toxicon. 2010;55(8):1510-8. PubMed PMID: 20223258.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Development of a sensitive enzyme immunoassay for measuring taipan venom in serum. AU - Kulawickrama,S, AU - O'Leary,M A, AU - Hodgson,W C, AU - Brown,S G A, AU - Jacoby,T, AU - Davern,K, AU - Isbister,G K, Y1 - 2010/03/16/ PY - 2010/01/26/received PY - 2010/02/27/revised PY - 2010/03/03/accepted PY - 2010/3/13/entrez PY - 2010/3/13/pubmed PY - 2010/7/22/medline SP - 1510 EP - 8 JF - Toxicon : official journal of the International Society on Toxinology JO - Toxicon VL - 55 IS - 8 N2 - The detection and measurement of snake venom in blood is important for confirming snake identification, determining when sufficient antivenom has been given, detecting recurrence of envenoming, and in forensic investigation. Venom enzyme immunoassays (EIA) have had persistent problems with poor sensitivity and high background absorbance leading to false positive results. This is particularly problematic with Australasian snakes where small amounts of highly potent venom are injected, resulting in low concentrations being associated with severe clinical effects. We aimed to develop a venom EIA with a limit of detection (LoD) sufficient to accurately distinguish mild envenoming from background absorbance at picogram concentrations of venom in blood. Serum samples were obtained from patients with taipan bites (Oxyuranus spp.) before and after antivenom, and from rats given known venom doses. A sandwich EIA was developed using biotinylated rabbit anti-snake venom antibodies for detection. For low venom concentrations (i.e. <1 ng/mL) the assay was done before and after addition of antivenom to the sample (antivenom difference method). The LoD was 0.15 ng/mL for the standard assay and 0.1 ng/mL for the antivenom difference method. In 11 pre-antivenom samples the median venom concentration was 10 ng/mL (Range: 0.3-3212 ng/mL). In four patients with incomplete venom-induced consumption coagulopathy the median venom concentration was 2.4 ng/mL compared to 30 ng/mL in seven patients with complete venom-induced consumption coagulopathy. No venom was detected in any post-antivenom sample and the median antivenom dose prior to this first post-antivenom sample was 1.5 vials (1-3 vials), including 7 patients administered only 1 vial. In rats the assay distinguished a 3-fold difference in venom dose administered and there was small inter-individual variability. There was small but measurable cross-reactivity with black snake (Pseudechis), tiger snake (Notechis) and rough-scale snake (Tropidechis carinatus) venoms with the assay for low venom concentrations (<1 ng/mL). The use of biotinylation and the antivenom difference method in venom EIA produces a highly sensitive assay that will be useful for determining antivenom dose, forensic and clinical diagnosis. SN - 1879-3150 UR - https://www.unboundmedicine.com/medline/citation/20223258/Development_of_a_sensitive_enzyme_immunoassay_for_measuring_taipan_venom_in_serum_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0041-0101(10)00103-0 DB - PRIME DP - Unbound Medicine ER -