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Bickler PE, Abouyannis M, Bhalla A, Lewin MR. Neuromuscular Weakness and Paralysis Produced by Snakebite Envenoming: Mechanisms and Proposed Standards for Clinical Assessment. Toxins (Basel) 2023; 15:49. [PMID: 36668869 PMCID: PMC9861841 DOI: 10.3390/toxins15010049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Revised: 11/23/2022] [Accepted: 12/10/2022] [Indexed: 01/11/2023] Open
Abstract
Respiratory and airway-protective muscle weakness caused by the blockade of neuromuscular transmission is a major cause of early mortality from snakebite envenoming (SBE). Once weakness is manifest, antivenom appears to be of limited effectiveness in improving neuromuscular function. Herein, we review the topic of venom-induced neuromuscular blockade and consider the utility of adopting clinical management methods originally developed for the safe use of neuromuscular blocking agents by anesthesiologists in operating rooms and critical care units. Failure to quantify neuromuscular weakness in SBE is predicted to cause the same significant morbidity that is associated with failure to do so in the context of using a clinical neuromuscular block in surgery and critical care. The quantitative monitoring of a neuromuscular block, and an understanding of its neurophysiological characteristics, enables an objective measurement of weakness that may otherwise be overlooked by traditional clinical examination at the bedside. This is important for the initial assessment and the monitoring of recovery from neurotoxic envenoming. Adopting these methods will also be critical to the conduct of future clinical trials of toxin-inhibiting drugs and antivenoms being tested for the reversal of venom-induced neuromuscular block.
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Affiliation(s)
- Philip E. Bickler
- Center for Exploration and Travel Health, California Academy of Science, San Francisco, CA 94118, USA
- Anesthesia and Perioperative Care, University of California at San Francisco, 513 Parnassus Ave, Medical Science Room S-257, San Francisco, CA 94143-0542, USA
| | - Michael Abouyannis
- Centre for Snakebite Research and Interventions, Liverpool School of Tropical Medicine, Liverpool L3 5QA, UK
| | - Ashish Bhalla
- Department of Internal Medicine, Postgraduate Institute of Medical Education and Research, Chandigarh 160012, India
| | - Matthew R. Lewin
- Center for Exploration and Travel Health, California Academy of Science, San Francisco, CA 94118, USA
- Ophirex, Inc., Corte Madera, CA 94925, USA
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2
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The Effect of Australian and Asian Commercial Antivenoms in Reversing the Post-Synaptic Neurotoxicity of O. hannah, N. naja and N. kaouthia Venoms In Vitro. Toxins (Basel) 2022; 14:toxins14040277. [PMID: 35448886 PMCID: PMC9024492 DOI: 10.3390/toxins14040277] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 04/08/2022] [Accepted: 04/11/2022] [Indexed: 01/23/2023] Open
Abstract
Despite antivenoms being the only established specific treatment for neuromuscular paralysis arising from snake envenoming, their ability to reverse the post-synaptic neurotoxicity in snake envenoming is poorly understood. We investigated the ability of five commercial antivenoms i.e., King cobra monovalent, Thai cobra monovalent, Thai neuro polyvalent, Indian polyvalent and Australian polyvalent antivenoms to reverse neurotoxicity induced by the venoms of King cobra (Ophiophagus hannah, 3 µg/mL), Indian cobra (Naja naja, 5 µg/mL) and Thai cobra (Naja kaouthia, 3 µg/mL) using the in vitro chick-biventer cervicis nerve–muscle preparation. All three venoms displayed post-synaptic neurotoxicity, which was prevented by all tested antivenoms (40 µL/mL) added to the bath prior to venom. All antivenoms partially reversed the established post-synaptic neuromuscular block after the addition of the three venoms during a 180 min observation period, but to varying degrees and at different rates. The neurotoxic effects of O. hannah venom recovered to a greater magnitude (based on twitch height restoration) and faster than the neurotoxicity of N. kaouthia venom, which recovered to a lower magnitude more slowly. The recovery of post-synaptic neurotoxicity by N. naja venom was hindered due to the likely presence of cytotoxins in the venom, which cause direct muscle damage. The observations made in this study provide further evidence that the commercial antivenoms are likely to actively reverse established α-neurotoxin-mediated neuromuscular paralysis in snake envenoming, and there is cross-neutralisation with different antivenoms.
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Huynh TM, Silva A, Isbister GK, Hodgson WC. Isolation and Pharmacological Characterization of α-Elapitoxin-Oh3a, a Long-Chain Post-Synaptic Neurotoxin From King Cobra ( Ophiophagus hannah) Venom. Front Pharmacol 2022; 13:815069. [PMID: 35341214 PMCID: PMC8942764 DOI: 10.3389/fphar.2022.815069] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Accepted: 01/31/2022] [Indexed: 11/13/2022] Open
Abstract
The King Cobra (Ophiophagus hannah) is the world's largest venomous snake and has a widespread geographical distribution throughout Southeast Asia. Despite proteomic studies indicating the presence of postsynaptic neurotoxins in O. hannah venom, there are few pharmacological investigations of these toxins. We isolated and characterized α-elapitoxin-Oh3a (α-EPTX-Oh3a; 7,938 Da), a long-chain postsynaptic neurotoxin, which constitutes 5% of O. hannah venom. α-EPTX-Oh3a (100-300 nM) caused concentration-dependent inhibition of indirect twitches and inhibited contractile responses of tissues to exogenous acetylcholine and carbachol, in the chick biventer cervicis nerve-muscle preparation. The prior incubation of tissues with Thai Red Cross Society King Cobra antivenom (1 ml/0.8 mg) prevented the in vitro neurotoxic effects of α-EPTX-Oh3a (100 nM). The addition of Thai Red Cross Society King Cobra antivenom (1 ml/0.8 mg), at the t90 time point partially reversed the in vitro neurotoxicity of α-EPTX-Oh3a (100 nM). Repeatedly washing the tissue did not allow significant recovery from the in vitro neurotoxic effects of α-EPTX-Oh3a (100 nM). α-EPTX-Oh3a demonstrated pseudo-irreversible antagonism of concentration-response curves to carbachol, with a pA2 of 8.99. De novo sequencing of α-EPTX-Oh3a showed a long-chain postsynaptic neurotoxin with 72 amino acids, sharing 100% sequence identity with Long neurotoxin OH-55. In conclusion, the antivenom is useful for reversing the clinically important long-chain α-neurotoxin-mediated neuromuscular paralysis.
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Affiliation(s)
- Tam M Huynh
- Monash Venom Group, Department of Pharmacology, Biomedical Discovery Institute, Monash University, Clayton, VIC, Australia
| | - Anjana Silva
- Monash Venom Group, Department of Pharmacology, Biomedical Discovery Institute, Monash University, Clayton, VIC, Australia.,Department of Parasitology, Faculty of Medicine and Allied Sciences, Rajarata University of Sri Lanka, Anuradhapura, Sri Lanka
| | - Geoffrey K Isbister
- Monash Venom Group, Department of Pharmacology, Biomedical Discovery Institute, Monash University, Clayton, VIC, Australia.,Clinical Toxicology Research Group, University of Newcastle, Newcastle, NSW, Australia
| | - Wayne C Hodgson
- Monash Venom Group, Department of Pharmacology, Biomedical Discovery Institute, Monash University, Clayton, VIC, Australia
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4
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Current research into snake antivenoms, their mechanisms of action and applications. Biochem Soc Trans 2021; 48:537-546. [PMID: 32196542 DOI: 10.1042/bst20190739] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Revised: 02/26/2020] [Accepted: 02/27/2020] [Indexed: 01/11/2023]
Abstract
Snakebite is a major public health issue in the rural tropics. Antivenom is the only specific treatment currently available. We review the history, mechanism of action and current developments in snake antivenoms. In the late nineteenth century, snake antivenoms were first developed by raising hyperimmune serum in animals, such as horses, against snake venoms. Hyperimmune serum was then purified to produce whole immunoglobulin G (IgG) antivenoms. IgG was then fractionated to produce F(ab) and F(ab')2 antivenoms to reduce adverse reactions and increase efficacy. Current commercial antivenoms are polyclonal mixtures of antibodies or their fractions raised against all toxin antigens in a venom(s), irrespective of clinical importance. Over the last few decades there have been small incremental improvements in antivenoms, to make them safer and more effective. A number of recent developments in biotechnology and toxinology have contributed to this. Proteomics and transcriptomics have been applied to venom toxin composition (venomics), improving our understanding of medically important toxins. In addition, it has become possible to identify toxins that contain epitopes recognized by antivenom molecules (antivenomics). Integration of the toxinological profile of a venom and its composition to identify medically relevant toxins improved this. Furthermore, camelid, humanized and fully human monoclonal antibodies and their fractions, as well as enzyme inhibitors have been experimentally developed against venom toxins. Translation of such technology into commercial antivenoms requires overcoming the high costs, limited knowledge of venom and antivenom pharmacology, and lack of reliable animal models. Addressing such should be the focus of antivenom research.
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Silva A, Maduwage K, Buckley NA, Lalloo DG, de Silva HJ, Isbister GK. Antivenom for snake venom-induced neuromuscular paralysis. Hippokratia 2017. [DOI: 10.1002/14651858.cd012604] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Anjana Silva
- Monash University; Department of Pharmacology; Victoria Australia
| | - Kalana Maduwage
- Faculty of Medicine, University of Peradeniya; Department of Biochemistry; Peradeniya Sri Lanka 24000
| | - Nick A Buckley
- University of Sydney; Department of Pharmacology; Blackburn Building D06 Sydney Medical School Camperdown NSW Australia 2006
| | - David G Lalloo
- Liverpool School of Tropical Medicine; Clinical Research Group; Pembroke Place Liverpool Merseyside UK L3 5QA
| | - H Janaka de Silva
- University of Kelaniya; Department of Medicine; PO Box 6 Ragama Sri Lanka
| | - Geoffrey K Isbister
- University of Newcastle; School of Medicine and Public Health; Edith St Waratah New South Wales Australia 2298
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Herrera M, de Cássia de O Collaço R, Villalta M, Segura Á, Vargas M, Wright CE, Paiva OK, Matainaho T, Jensen SD, León G, Williams DJ, Rodrigues-Simioni L, Gutiérrez JM. Neutralization of the neuromuscular inhibition of venom and taipoxin from the taipan (Oxyuranus scutellatus) by F(ab')2 and whole IgG antivenoms. Toxicol Lett 2015; 241:175-83. [PMID: 26621539 DOI: 10.1016/j.toxlet.2015.11.020] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Revised: 11/05/2015] [Accepted: 11/21/2015] [Indexed: 11/25/2022]
Abstract
The neuromuscular junction activity of Oxyuranus scutellatus venom and its presynaptic neurotoxin, taipoxin, and their neutralization by two antivenoms were examined in mouse phrenic nerve-diaphragm preparations. The action of taipoxin was also studied at 21°C. The efficacy of the antivenoms was also assessed in an in vivo mouse model. Both antivenoms were effective in neutralizing the neuromuscular blocking activity in preincubation-type experiments. In experiments involving independent addition of venom and antivenoms, neutralization depended on the time interval between venom addition and antivenom application. When taipoxin was incubated for 5, 10 or 20min at 21°C, and antivenom added and temperature increased to 37°C, neutralization was achieved only when the toxin was incubated for 5 or 10min. The neutralization by the two antivenoms in an in vivo model showed that both whole IgG and F(ab')2 antivenoms were effective in neutralizing lethality. Our findings highlight the very rapid action of taipan venom at the nerve terminal, and the poor capacity of antivenoms to revert neurotoxicity as the time interval between venom or taipoxin application and antivenom addition increased. Additionally the disparity between molecular masses of the active substances of the two antivenoms did not result in differences in neutralization.
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Affiliation(s)
- María Herrera
- Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José, Costa Rica
| | - Rita de Cássia de O Collaço
- Department of Pharmacology, Faculty of Medical Sciences, State University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Mauren Villalta
- Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José, Costa Rica
| | - Álvaro Segura
- Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José, Costa Rica
| | - Mariángela Vargas
- Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José, Costa Rica
| | - Christine E Wright
- Australian Venom Research Unit, Department of Pharmacology and Therapeutics, University of Melbourne, Parkville, Victoria, Australia
| | - Owen K Paiva
- Charles Campbell Toxinology Centre, School of Medicine & Health Sciences, University of Papua New Guinea, Port Moresby, Papua New Guinea
| | - Teatulohi Matainaho
- Charles Campbell Toxinology Centre, School of Medicine & Health Sciences, University of Papua New Guinea, Port Moresby, Papua New Guinea
| | - Simon D Jensen
- Australian Venom Research Unit, Department of Pharmacology and Therapeutics, University of Melbourne, Parkville, Victoria, Australia; Charles Campbell Toxinology Centre, School of Medicine & Health Sciences, University of Papua New Guinea, Port Moresby, Papua New Guinea
| | - Guillermo León
- Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José, Costa Rica
| | - David J Williams
- Australian Venom Research Unit, Department of Pharmacology and Therapeutics, University of Melbourne, Parkville, Victoria, Australia; Charles Campbell Toxinology Centre, School of Medicine & Health Sciences, University of Papua New Guinea, Port Moresby, Papua New Guinea
| | - Léa Rodrigues-Simioni
- Department of Pharmacology, Faculty of Medical Sciences, State University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - José María Gutiérrez
- Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José, Costa Rica.
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Engineering venom's toxin-neutralizing antibody fragments and its therapeutic potential. Toxins (Basel) 2014; 6:2541-67. [PMID: 25153256 PMCID: PMC4147596 DOI: 10.3390/toxins6082541] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2014] [Revised: 07/16/2014] [Accepted: 08/04/2014] [Indexed: 11/24/2022] Open
Abstract
Serum therapy remains the only specific treatment against envenoming, but anti-venoms are still prepared by fragmentation of polyclonal antibodies isolated from hyper-immunized horse serum. Most of these anti-venoms are considered to be efficient, but their production is tedious, and their use may be associated with adverse effects. Recombinant antibodies and smaller functional units are now emerging as credible alternatives and constitute a source of still unexploited biomolecules capable of neutralizing venoms. This review will be a walk through the technologies that have recently been applied leading to novel antibody formats with better properties in terms of homogeneity, specific activity and possible safety.
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8
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Harris JB, Scott-Davey T. Secreted phospholipases A2 of snake venoms: effects on the peripheral neuromuscular system with comments on the role of phospholipases A2 in disorders of the CNS and their uses in industry. Toxins (Basel) 2013; 5:2533-71. [PMID: 24351716 PMCID: PMC3873700 DOI: 10.3390/toxins5122533] [Citation(s) in RCA: 104] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2013] [Revised: 12/02/2013] [Accepted: 12/10/2013] [Indexed: 01/02/2023] Open
Abstract
Neuro- and myotoxicological signs and symptoms are significant clinical features of envenoming snakebites in many parts of the world. The toxins primarily responsible for the neuro and myotoxicity fall into one of two categories--those that bind to and block the post-synaptic acetylcholine receptors (AChR) at the neuromuscular junction and neurotoxic phospholipases A2 (PLAs) that bind to and hydrolyse membrane phospholipids of the motor nerve terminal (and, in most cases, the plasma membrane of skeletal muscle) to cause degeneration of the nerve terminal and skeletal muscle. This review provides an introduction to the biochemical properties of secreted sPLA2s in the venoms of many dangerous snakes and a detailed discussion of their role in the initiation of the neurologically important consequences of snakebite. The rationale behind the experimental studies on the pharmacology and toxicology of the venoms and isolated PLAs in the venoms is discussed, with particular reference to the way these studies allow one to understand the biological basis of the clinical syndrome. The review also introduces the involvement of PLAs in inflammatory and degenerative disorders of the central nervous system (CNS) and their commercial use in the food industry. It concludes with an introduction to the problems associated with the use of antivenoms in the treatment of neuro-myotoxic snakebite and the search for alternative treatments.
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Affiliation(s)
- John B. Harris
- Medical Toxicology Centre and Institute of Neurosciences, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Tracey Scott-Davey
- Experimental Scientific Officer, Electron Microscopy Unit, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, UK; E-Mail:
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9
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Abstract
Snakebite is classified by the WHO as a neglected tropical disease. Envenoming is a significant public health problem in tropical and subtropical regions. Neurotoxicity is a key feature of some envenomings, and there are many unanswered questions regarding this manifestation. Acute neuromuscular weakness with respiratory involvement is the most clinically important neurotoxic effect. Data is limited on the many other acute neurotoxic manifestations, and especially delayed neurotoxicity. Symptom evolution and recovery, patterns of weakness, respiratory involvement, and response to antivenom and acetyl cholinesterase inhibitors are variable, and seem to depend on the snake species, type of neurotoxicity, and geographical variations. Recent data have challenged the traditional concepts of neurotoxicity in snake envenoming, and highlight the rich diversity of snake neurotoxins. A uniform system of classification of the pattern of neuromuscular weakness and models for predicting type of toxicity and development of respiratory weakness are still lacking, and would greatly aid clinical decision making and future research. This review attempts to update the reader on the current state of knowledge regarding this important issue.
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Affiliation(s)
- Udaya K. Ranawaka
- Faculty of Medicine, University of Kelaniya, Ragama, Sri Lanka
- * E-mail:
| | - David G. Lalloo
- Liverpool School of Tropical Medicine, Liverpool, United Kingdom
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Abstract
Snake bite is a common and frequently devastating environmental and occupational disease, especially in rural areas of tropical developing countries. Its public health importance has been largely ignored by medical science. Snake venoms are rich in protein and peptide toxins that have specificity for a wide range of tissue receptors, making them clinically challenging and scientifically fascinating, especially for drug design. Although the full burden of human suffering attributable to snake bite remains obscure, hundreds of thousands of people are known to be envenomed and tens of thousands are killed or maimed by snakes every year. Preventive efforts should be aimed towards education of affected communities to use proper footwear and to reduce the risk of contact with snakes to a minimum through understanding of snakes' behaviour. To treat envenoming, the production and clinical use of antivenom must be improved. Increased collaboration between clinicians, epidemiologists, and laboratory toxinologists should enhance the understanding and treatment of envenoming.
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Affiliation(s)
- David A Warrell
- Nuffield Department of Clinical Medicine, University of Oxford, John Radcliffe Hospital, Oxford, UK.
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Prasarnpun S, Walsh J, Awad SS, Harris JB. Envenoming bites by kraits: the biological basis of treatment-resistant neuromuscular paralysis. ACTA ACUST UNITED AC 2005; 128:2987-96. [PMID: 16195243 DOI: 10.1093/brain/awh642] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Beta-bungarotoxin, a neurotoxic phospholipase A2 is a major fraction of the venom of kraits. The toxin was inoculated into one hind limb of young adult rats. The inoculated hind limb was paralysed within 3 h, and remained paralysed for 2 days. The paralysis was associated with the loss of synaptic vesicles from motor nerve terminal boutons, a decline in immunoreactivity of synaptophysin, SNAP-25 and syntaxin, a loss of muscle mass and the upregulation of NaV(1.5) mRNA and protein. Between 3 and 6 h after the inoculation of toxin, some nerve terminal boutons exhibited clear signs of degeneration. Others appeared to be in the process of withdrawing from the synaptic cleft and some boutons were fully enwrapped in terminal Schwann cell processes. By 12 h all muscle fibres were denervated. Re-innervation began at 3 days with the appearance of regenerating nerve terminals, a return of neuromuscular function in some muscles and a progressive increase in the immunoreactivity of synaptophysin, SNAP-25 and syntaxin. Full recovery occurred at 7 days. The data were compared with recently published clinical data on envenoming bites by kraits and by extrapolation we suggest that the acute, reversible denervation caused by beta-bungarotoxin is a credible explanation for the clinically important, profound treatment-resistant neuromuscular paralysis seen in human subjects bitten by these animals.
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Affiliation(s)
- S Prasarnpun
- School of Neurology, Neurobiology and Psychiatry, Faculty of Medical Sciences, University of Newcastle upon Tyne, UK
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Gutiérrez JM, León G, Lomonte B. Pharmacokinetic-pharmacodynamic relationships of immunoglobulin therapy for envenomation. Clin Pharmacokinet 2004; 42:721-41. [PMID: 12846594 DOI: 10.2165/00003088-200342080-00002] [Citation(s) in RCA: 142] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Parenteral administration of horse- and sheep-derived antivenoms constitutes the cornerstone in the therapy of envenomations induced by animal bites and stings. Depending on the type of neutralising molecule, antivenoms are made of: (i) whole IgG molecules (150 kDa), (ii) F(ab')(2) immunoglobulin fragments (100 kDa) or (iii) Fab immunoglobulin fragments (50 kDa). Because of their variable molecular mass, these three types of antivenoms have different pharmacokinetic profiles. Fab fragments have the largest volume of distribution and readily reach extravascular compartments. They are catabolised mainly by the kidney, having a more rapid clearance than F(ab')(2) fragments and IgG. On the other hand, IgG molecules have a lower volume of distribution and a longer elimination half-life, showing the highest cycling through the interstitial spaces in the body. IgG elimination occurs mainly by extrarenal mechanisms. F(ab')(2) fragments display a pharmacokinetic profile intermediate between those of Fab fragments and IgG molecules. Such diverse pharmacokinetic properties have implications for the pharmacodynamics of these immunobiologicals, since a pronounced mismatch has been described between the pharmacokinetics of venoms and antivenoms. Some venoms, such as those of scorpions and elapid snakes, are rich in low-molecular-mass neurotoxins of high diffusibility and large volume of distribution that reach their tissue targets rapidly after injection. In contrast, venoms rich in high-molecular-mass toxins, such as those of viperid snakes, have a pharmacokinetic profile characterised by a rapid initial absorption followed by a slow absorption process from the site of venom injection. Such delayed absorption has been linked with recurrence of envenomation when antibody levels in blood decrease. This heterogeneity in pharmacokinetics and mechanism of action of venom components requires a detailed analysis of each venom-antivenom system in order to determine the most appropriate type of neutralising molecule for each particular venom. Besides having a high affinity for toxicologically relevant venom components, an ideal antivenom should possess a volume of distribution as similar as possible to that of the toxins being neutralised. Moreover, high levels of neutralising antibodies should remain in blood for a relatively prolonged time to assure neutralisation of toxins reaching the bloodstream later in the course of envenomation, and to promote redistribution of toxins from extravascular compartments to blood. Additional studies are required on different venoms and antivenoms in order to further understand the pharmacokinetic-pharmacodynamic relationships of antibodies and their fragments and to optimise the immunotherapy of envenomations.
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Affiliation(s)
- José María Gutiérrez
- Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José, Costa Rica.
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Jones RG, Lee L, Landon J. The effects of specific antibody fragments on the 'irreversible' neurotoxicity induced by Brown snake (Pseudonaja) venom. Br J Pharmacol 1999; 126:581-4. [PMID: 10188967 PMCID: PMC1565833 DOI: 10.1038/sj.bjp.0702286] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Brown snake (Pseudonaja) venom has been reported to produce 'irreversible' post synaptic neurotoxicity (Harris & Maltin, 1981; Barnett et al., 1980). A murine phrenic nerve/diaphragm preparation was used to study the neurotoxic effects of this venom and pre- and post-synaptic components were distinguished by varying the temperature and frequency of nerve stimulation. There were no myotoxic effects and the neurotoxicity proved irreversible by washing alone. The effects of a new Fab based ovine antivenom have been investigated and proved able to produce a complete, rapid (< 1 h) reversal of the neurotoxicity induced by Brown snake venom. A reversal was also possible when the antivenom addition was delayed for a further 60 min. We believe that this is the first time such a reversal has been shown.
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Affiliation(s)
- R G Jones
- Department of Chemical Pathology, The Medical College of St. Bartholomew's Hospital, London
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14
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Abstract
Using the ELISA we have shown that in rats subcutaneously injected with Tityus serrulatus scorpion venom there is a fast absorption rate, a fast and high distribution of venom to tissues, a great affinity of the venom for the tissues and a slow elimination half-life. Because of these experimental data, i.v. immunotherapy should be given to patients stung by scorpions as soon as possible after hospital admission. The severity of scorpion envenoming is related to plasma venom concentration (ELISA). The high levels of plasma scorpion venom antigens (ELISA) were cleared 1 h after the infusion of antivenom (5-30 ml of Fab2 fragment) and high concentrations of circulating antivenom persisted for at least 24 h, confirming the efficacy of immunotherapy to neutralise circulating venom. Some symptoms (e.g. local pain and vomiting) decreased 1 h after the starting of immunotherapy, whereas the other symptoms disappeared from 12-48 h later. Using our tripartite approach of treating scorpion envenoming (symptomatic measures, support of vital functions and serotherapy), the mortality rate was very low (0.28%).
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Affiliation(s)
- N A Rezende
- Departamento de Clínica Médica, Faculdade de Medicina, UFMG, Belo Horizonte, Brazil
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15
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Abstract
A century after the discovery of antivenom and despite real progress undertaken in its manufacture, its use remains largely empirical. Recent studies of pharmacokinetics of envenoming permitted improved understanding of immunotherapy. Improved purification of the antivenom by using immunoglobulin fragments has lead to increased tolerance and efficiency of antivenom. The respective advantages and disadvantages of F(ab')2 and F(ab) are discussed in relation to neutralising efficacy and clearance from the circulation. Although the time during which the action of antivenom remains beneficial after the bite is unknown, the superiority of intravenous administration has now been proved. Although immunisation procedures and purification and use of IgG fragments can be improved using modern technology, the future of immunotherapy seems promising. It is vital that therapeutic protocols should be rigidly adhered to in order to optimise immunotherapy. The use of vaccination has yet to be explored.
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Jones D, Sawicki G, Wozniak M. Sequence, structure, and expression of a wasp venom protein with a negatively charged signal peptide and a novel repeating internal structure. J Biol Chem 1992. [DOI: 10.1016/s0021-9258(18)42121-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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Harris JB, Blain PG. Introduction to the toxicology of muscle. BAILLIERE'S CLINICAL ENDOCRINOLOGY AND METABOLISM 1990; 4:665-86. [PMID: 2268230 DOI: 10.1016/s0950-351x(05)80071-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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18
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Harris JB. Snake venoms in science and clinical medicine. 3. Neuropharmacological aspects of the activity of snake venoms. Trans R Soc Trop Med Hyg 1989; 83:745-7. [PMID: 2617644 DOI: 10.1016/0035-9203(89)90313-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Neuromuscular weakness is a common feature of snake bite. The toxins responsible for weakness either block neuromuscular transmission or they are myotoxic and damage skeletal muscle. In this article the major classes of toxins responsible for causing neuromuscular weakness are described. It is shown how a detailed knowledge of the biochemical and pharmacological properties of the toxins is essential if the clinical problems associated with bites by many species are to be properly understood. It is also shown that such an understanding allows apparent discrepancies between 'laboratory' and 'clinical' findings to be resolved.
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Affiliation(s)
- J B Harris
- School of Neurosciences, University of Newcastle, UK
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Danse JM, Kempf J. Preparation and characterization of monoclonal antibodies against beta-bungarotoxin and its A- and B-chains. Toxicon 1989; 27:1011-9. [PMID: 2799834 DOI: 10.1016/0041-0101(89)90152-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Splenocytes from Balb/c mice immunized with beta-bungarotoxin, a protein neurotoxin that exhibits phospholipase A2 activity, were fused with SP2/0 murine myeloma cells. Eighty-seven stable hybridoma cell lines were established which secrete monoclonal antibodies of the subclass IgG1 and K light chain and react with intact neurotoxin. Some antibodies were further analyzed. These recognize at least two immuno-dominant regions located on the A- and B-chains of the toxin, and the native toxin but show no crossreactivity with a protein homologous to chain A (porcine pancreas phospholipase A2) nor to chain B (toxin 1 from Dendroaspis polylepis). Two monoclonal antibodies inhibit phospholipase A2 activity of the neurotoxin but only one partially neutralizes its biological activity when injected together with the toxin, delaying the time of death.
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Affiliation(s)
- J M Danse
- INSERM U-184, Institut de Chimie Biologique, Faculté de Médecine, Strasbourg, France
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