A Strategy for Efficient Preparation of Genus-Specific Diagnostic Antibodies for Snakebites

Abstract

As said by former United Nations Secretary-General Kofi Annan, “Snakebite is the most important tropical disease you’ve never heard of.” Listed as a priority neglected tropical disease by the World Health Organization, snakebite envenoming (SBE) kills in excess of 125,000 people per year. However, due to the complexity and overlap of snake venom compositions, few reliable venom diagnostic methods for genus-/species-specific identification, which is crucial for successful SBE therapy, are available. Here, we develop a strategy to select and prepare genus-specific snake venom antibodies, which allows rapid and efficient clinical diagnosis of snakebite. Multi-omics approaches are used to choose candidate antigens from snake venoms and identify genus-specific antigenic epitope peptide fragments (GSAEPs) with ideal immunogenicity, specificity, and spatial accessibility. Double-antibody sandwich ELISA kit was established by matching a polyclonal antibody against a natural antigen and a monoclonal antibody that was prepared by natural protein as antigen and can specifically target the GSAEPs. The kit shows the ability to accurately identify venoms from similar genera of Trimeresurus and Protobothrops with a detection limit of 6.25 ng/ml on the snake venoms and a little cross-reaction, thus proving high feasibility and applicability.

Case Report: Management of an Uncommon Crotaline Snakebite (Ovophis makazayazaya)

“…1 There are similar clinical manifestations present in bites from these closely related species of snakebites. 13 This information is helpful to clinicians with limited knowledge of particular snake species to manage snakebites. For example, an O. convictus bite causes tissue swelling, pain, ecchymosis, thrombocytopenia, and consumptive coagulopathy, for which treatment with antivenom for Trimeresurus albolabris (green pit viper) was suggested.…”

“…Therefore, the bivalent antivenom for T. s. stejnegeri and P. mucrosquamatus was used for patient treatment, assuming a similar immunoreactivity and possible para-specific effect of the green pit viper T. s. stejnegeri antivenom against the Ovophis venom. 13 Antivenom administration was decided by the treating physicians. For managing the two common crotaline snakebites from T. s. stejnegeri and P. mucrosquamatus, the standard protocol is to administer 2, 4, and 8 vials for swelling grades 2 (swelling involving a whole hand or foot), 3 (swelling from the hand to the forearm or from the foot to the leg), and 4 (swelling extending to the whole arm, thigh, or the area above) following a distal limb bite, [7][8][9] respectively, based on the assumption that serum venom levels correlate with swelling grades, 18,19 and based on clinical observations that antivenom administration increases with swelling grades.…”

Antivenom availability, delays and use in Australia

“…This appeared to be an excellent approach, allowing a smaller and potentially safer dose of antivenom containing antibodies specific for the snake type. Outside of Australia, many perceived this to be a superior approach and various venom detection assay systems were subsequently developed in some countries ( Liu et al, 2018 ; Long et al, 2021 ; Maduwage et al, 2020 ). Others recognised that there were issues with snake venom detection, particularly enzyme immunoassays, which do not always differentiate venoms of related snakes, because of non-specific reactions and cross-reactivity ( Minton, 1987 ).…”

Challenges and Opportunities in Clinical Diagnostic Routine of Envenomation Using Blood Plasma Proteomics

“…The purification of antibodies from these preparations can compromise the reliability of the number and type of toxins detected, since detection will be dependent on the presence of antibodies that recognize a particular toxin. Therefore, we believe that the study of the production of genus-specific antibodies for venomous animals is indispensable and can be obtained through various techniques of immunization of animals [ 88 , 89 ].…”