Effect of Preservatives on IgG Aggregation, Complement-activating Effect and Hypotensive Activity of Horse Polyvalent Antivenom Used in Snakebite Envenomation (original) (raw)
Related papers
2009
We have evaluated for the first time the impact of a solvent/detergent (S/D) treatment on the quality and in vivo neutralization potency of horse-derived whole IgG antivenom used in the treatment of viperid snake bite envenoming in Central America. The S/D treatment by 1% tri (nbutyl) phosphate (TnBP) e 1% Triton X-45 at 22e25 C was applied either on starting plasma or on purified immunoglobulins. The S/D agents were removed from both fractions by extractions with oil. S/D-treated plasma was subjected to caprylic acid precipitation to purify the immunoglobulins. Products were formulated, sterile-filtered, and filled into 10-mL vials, stored at 5 AE 3 C, and subjected to routine quality controls, SDS-PAGE, determination of anti-Bothrops asper venom antibody titre by ELISA, in vivo B. asper venom-neutralization potency tests, and safety test, comparatively with an antivenom manufactured by caprylic acid fractionation without S/D treatment. Results indicate that these conditions of S/D treatment on purified immunoglobulin yielded an antivenom of high turbidity that induced weight loss in animals. In contrast, antivenom fractionated from the S/D-treated plasma had physico-chemical and biological characteristics indistinguishable from those of the non-S/D-treated antivenom. S/D treatment of horse plasma may be considered to increase the viral safety of antivenoms.
Toxicon, 2005
Early adverse reactions occur in a number of patients treated with heterologous antivenoms and have been associated with anticomplementary activity (ACA). In order to reduce the ACA of equine whole IgG antivenoms produced by caprylic acid fractionation, three different fractionation protocols were compared: (a) routine caprylic acid fractionation; (b) caprylic acid fractionation followed by b-propiolactone treatment; and (c) caprylic acid fractionation followed by ion-exchange chromatography using a quaternary ammonium membrane. The three protocols yielded products with similar physicochemical characteristics and anti-Bothrops asper venom antibody titers, except that ion-exchange purified antivenom had a lower protein concentration. Antivenoms fractionated by using b-propiolactone or filtration through quaternary ammonium membrane had a significantly reduced in vitro ACA. A preparation of caprylic acid-fractionated antivenom was heated in order to induce the formation of protein aggregates; however, its ACA was similar to non-heated antivenom. None of the antivenoms affected the hemolytic activity of serum complement in rabbits after a bolus intravenous administration. It is concluded that (a) b-propiolactone and quaternary ammonium membranes significantly reduce in vitro ACA of caprylic acid-fractionated equine antivenom, and (b) the validity of in vitro ACA as a predictor of EAR needs to be reexamined in clinical and experimental studies, since it may not adequately predict in vivo complement activation by antivenoms. q
2012
Low pH treatment improves the tolerance to intravenous infusion, the stability, and the viral safety of various therapeutic immunoglobulins G preparations, but has never been evaluated for horse plasmaderived antivenoms. We have studied the impact of low pH formulation on the quality, safety, stability, potency and viral inactivation of a whole IgG antivenom used to treat viperid snake bite envenoming. Horse plasma-derived whole immunoglobulins purified by caprylic acid were incubated for 24 h at low pH in the presence of 4% sorbitol, then sterile-filtered and stored liquid at 2e8 C. Appearance, aggregates, purity, safety tests in mice, venom antibody titre, and neutralization potency tests were controlled. Low pH treatment did not affect the physico-chemical characteristics, safety and potency of antivenom for at least 6 months of storage, but a major increase in aggregates was observed. In vitro antibody titre and in vivo neutralizing potency were maintained. There were ! 5.5 log inactivation of Herpes Simplex Virus-1, an enveloped virus, but no significant inactivation of the non-enveloped Poliovirus type 3. Low pH treatment appears feasible to improve the viral safety of antivenoms without affecting the neutralization potency. The possibility to formulate antivenoms at low pH requires further investigations to avoid formation of aggregates.
Toxicon, 2008
The effect of Bothrops antivenom on blocking the disturbances induced by Bothrops jararaca venom in leukocyte-endothelial interactions (LEI) at the microcirculation of the cremaster muscle in mice was evaluated using intravital microscopy. Our findings showed that an i.v. injection of Bothrops antivenom, per se, induced changes in LEI, similar to those induced by an s.c. injection of B. jararaca venom, and that Bothrops antivenom can also induce ephemeral symptoms, such as tremor and dyspnea in mice. These effects were mostly due to phenol used in Bothrops antivenom as a preservative, since animals injected i.v. with a phenol solution, but not with phenol-free Bothrops antivenom, presented those effects on LEI, and also tremor and dyspnea. In addition, phenol-free antivenom abrogated venom-induced changes in LEI parameters. The present data demonstrate that Bothrops antivenom contains antibodies that neutralize toxins of B. jararaca venom that impair LEI, and suggest that the phenol used as a preservative in it can originate some undesired effects.
2014
Context. Therapy for snakebites relies on the application of antivenoms, which may be produced with different immunogenic mixtures of venom and possess different pharmaceutical characteristics. For these reasons, immunological cross-reactivity and heterologous neutralization were analyzed relative to the protein content of three antivenoms used in the Americas. Methods. The antivenoms studied were composed of equine F(ab ′ ) 2 fragments from animals immunized with Crotalinae venoms. The antivenoms were tested against venoms of seven pit viper species from Argentina, seven from Mexico, one from Costa Rica, and one from Colombia. Results . Immunoblotting showed high cross-reactivity of all major protein bands with all the antivenoms tested. ELISA results also showed high cross-reactivity among the different venoms and antivenoms, and a high heterologous neutralization was observed. The results can be interpreted in different ways depending on whether the reactivity is considered in terms of the volume of antivenom used or by the amount of protein contained in this volume of antivenom. The antivenoms with high immunochemical reactivity and neutralizing capacity were those with higher protein content per vial; but when doses were adjusted by protein content, antivenoms of apparently lower neutralizing capacity and immunochemical reactivity showed at least similar potency and reactivity although volumetrically at higher doses. Conclusion. Protein content relative to neutralization potency of different products must be taken into account when antivenoms are compared, in addition to the volume required for therapeutic effect. These results show the importance of obtaining high-affi nity and high-avidity antibodies to achieve good neutralization using low protein concentration and low-volume antivenoms.
Toxicon, 1988
alternative in vitro method for testing the potency of the polyvalent antivenom produced in Costa Rica. Toxicon 26, 411-413, 1988 . -The ability of several batches of polyvalent antivenom to neutralize indirect hemolytic activity of Bothrops riper venom was studied using a sensitive plate test . All samples of antivenom tested effectively neutralized this activity . A highly significant correlation was observed between neutralization of indirect hemolytis and neutralization of lethal activity . This simple and sensitive in vitro test could be used to monitor antibody levels in horses immunized to produce polyvalent antivenom .
The neutralization efficacy of expired polyvalent antivenoms: An alternative option
Toxicon, 2019
The expense of production and distribution of snakebite antivenom, as well as its relatively infrequent use, has caused antivenom to be increasingly difficult to obtain and ultimately producing an alarming global shortage. Unused, expired antivenom may represent a significant, untapped resource to ameliorate this crisis. This study examines the efficacy of expired antivenom over time using in vitro, whole blood clotting, and platelet function statistics. Representatives from three years for four different global brands of polyvalent antivenom were chosen and tested against their corresponding venoms as well as other venoms that could display cross-reactivity. These antivenoms include Wyeth Polyvalent (
Biologicals, 2010
Administration of antivenoms to treat snakebite envenomings has the potential risk of inducing early adverse reactions. The mechanisms involved in these reactions are unclear. In this study, polyspecific antivenom consisting of whole IgG purified from equine plasma by caprylic acid precipitation was administered intravenously to non-envenomed horses (n ¼ 47) and cows (n ¼ 20) at a dose of 0.4 mL/kg. It has been reported that, in humans, this formulation (administered at a dose of 0.4 mL/kg) induces mild noticeable early adverse reactions, such as fever, vomiting, diarrhea, urticaria, generalized rash, tachypnea or tachycardia, in about 15e20% of the patients. Unexpectedly, none of the animals receiving antivenom in our study showed any evidence of early adverse reaction. Moreover, no late adverse reactions, i.e. serum sickness, were observed during 40 days after antivenom administration. Unlike studies performed in envenomed humans, our present results were obtained in a group of non-envenomed individuals. It is concluded that, in addition to the physicochemical characteristics of the formulation, other unknown factors must determine the occurrence of adverse reactions in snakebite envenomed humans treated with equine-derived antivenoms.