Acute-phase reactions, including cytokines, in patients bitten by Bothrops and Crotalus snakes in Brazil

Thirty-one patients bitten by venomous snakes in Botucatu area (State of Säo Paulo - Brazil), sixteen by Bothrops spp. and fifteen by Crotalus durissus terrificus, were studied. The group comprised twenty-nine males and two females, ranging from fourteen to sixty-three years of age (mean 33 ñ 15.Leukocytosis with neutrophilia and lymphopenia, increase of mucoproteins and C reactive protein, decrease of total serum protein and albumin, were observed on the first day after the accident. In addition, increased serum levels of the cytokines IL-6 and IL-8, but not of IL-1 beta and TNF-alpha, were observed. The alterations were generally more intense in patients bitten by Crotalus durissus terrificus than by Bothrops spp. It is concluded that these snakebite envenomations closely resemble an acute trauma, inducing a typical acute-phase response.

Immunoenzymatic quantitation of antibodies to Bothrops asper myotoxins after polyvalent antivenom administration in mice

Two quantitative enzyme-ummunoassays (EIA) for Bothrops asper myotoxin and anti-myotoxin antibodies, respectively, were utilized to study their in vivo distribution in mice (Swiss, 18 to 20 g). After polyvalent antivenom (0.4 ml) administration by the iv route, there was an immediated peak in plasma anti-myotoxin antibodies which declined rapidly during the first hour, and then decreased more gradually. Anti-myotoxin antibodies were detected in muscular tissue (gastrocnemius) following iv injection of antivenom. After im injection of antivenom (0.4 ml), a slow and steady increase in plasma anmti-myotoxin levels was observed, with a peak at 24 h. Mice that received antivenom (0.4 ml) by the iv or im route 15 min after im injection of B. asper venom (100 ug) had lower levels of plasma anti-myotoxin antibodies than controls injected with antivenom only, suggesting that at least a fraction of the antibodies combines with myotoxins in vivo. Myotoxin was not detected in plasma at any time after venom injection by the im (100 ug) or ip (40 ug) route. Following iv injection of 50 ug of purified myotoxin II, all plasma samples were also negative, at a detection limit of 10 ng/ml. It was demonstrated that myotoxin II binds to mouse erythrocytes in vitro, a fact that could partially explain its rapid in vivo disappearance from plasma. The present results on the distribution of anti-myotoxin antibodies in vivo are in agreement with previous experimental studies reporting the poor neutralization of myotoxicity induced by B. asper venom when antivenom is injected im, in comparison to iv injection

Neutralization of coral snake Micrurus nigrocinctus venom by a monovalent antivenom

The neutralizing ability of a monovalent anti-Micrurus nigrocinctus (coral snake) antivenom produced in Costa Rica was tested against the letal, myotoxic and phospholipase A, activities of homologous venom. In addition, immunodiffusion and Western blot analyses were performed. in experiments where venom and antivenom were incubated prior to the test, antivenom was effective in neutralizing lethal, myotoxic and phospholipase A2, activities, with Effective Doses 50% of 2700 *l antivenom/mg venom, 1840 *l antivenom/mg venom, and 3630 *l antivenom, respectively. When coral snake antivenom was administered different times after coral snake venom injection, neutralization of lethality was achieved ehen antivenom was injected iv immediately and 15 min after venom. In contrast, lethaly was not reduced when antivenom was administered by the route. Only partial neutralization of myotoxixity was observed even when antivenom was injected iv immediately after envenomation. Immunodiffusion and immunoblot analyses demonstrated the presence of antibodies in antivenom against several, but not all, venom components

South American snake venom proteins antigenically related to bothrops asper myotoxins

1. the presence of proteins antigenically related to Bothrops asper myotoxins in various snake venoms, mainly from South America, was investigated by using poluclonal and monoclonal antibodies. 2. Myotoxin-like components were detected in the bothrops venoms from South america, and in the venoms of Crotalus atrox (North america), Trimerusurus flavoviridis (Japan), and Micrurus alleni (Costa Rica). 3. Cross-reactive components detected in several Bothrops venoms show a common subunit of 15-16 LDa by sodium dodcyl sulphate-polyacrylamide gel electrophoresis, although significant charge variations are evident by immunoelectrophoresis. 4. It is concluded that proteins antigenically related to B. asper nyotoxins are relatively common in the genus Bothrops and, in the light of findings discussed, are likely to posses myotoxic activity