Dose and time dependence of box jellyfish antivenom.

Athena Andreosso,Jamie E Seymour,Michael J Smout

doi:10.1186/1678-9199-20-34

Abstract

BackgroundThe effectiveness of the currently available box jellyfish (Chironex fleckeri) antivenom has been subject of debate for many years. To assess whether the box jellyfish antivenom has the ability to attenuate venom-induced damage at cellular level, the present study analyzed the dose and time dependence of the antivenom in a cell-based assay.MethodsDifferent doses of antivenom were added to venom and subsequently administered to cells and the cell index was measured using xCelligence Technology (ACEA Biosciences). Similarly, antivenom and venom were incubated over different time periods and cell survival measured as stated above. For both experiments, the cell index was plotted as a measure of cell survival against the dose or incubation time and significance was determined with the use of a one-way ANOVA with a LSD post hoc test.ResultsIncreasing concentrations of antivenom significantly augmented cell survival, with a concentration of approximately five times the currently recommended dose for human envenomation, causing the first significant increase in cell survival compared venom alone. Further, cell survival improved with increasing incubation time of venom and antivenom prior to addition to the cells, indicating that box jellyfish antivenom requires approximately 70 minutes to neutralize C. fleckeri venom.ConclusionThe presented results suggest that the currently recommended dose of antivenom requires adjustment, and more importantly, a human trial to test the effects of higher concentrations is also necessary. Further, antivenom has delayed neutralizing effects (i.e. after 70 minutes) which underlines the eminence of immediate and prolonged cardiopulmonary resuscitation in victims suffering from a C. fleckeri venom-induced cardiovascular collapse.

Highlights

The effectiveness of the currently available box jellyfish (Chironex fleckeri) antivenom has been subject of debate for many years
Since C. fleckeri venom is distributed through the vascular system, it potentially leads to rapid cardiovascular collapse
Venom extraction Adult specimens of C. fleckeri were collected near Napranum, Qld, Australia (12.6835° S, 141.8884° E) in November 2011; tentacles were removed and nematocysts were collected according to Bloom et al [13]

Summary

Introduction

The effectiveness of the currently available box jellyfish (Chironex fleckeri) antivenom has been subject of debate for many years. Chironex fleckeri envenomation victims are commonly given CSL antivenom via intramuscular injection and there are several reports of pain amelioration as well as successful recovery of severely envenomed patients following its administration [2,3]. The venom currently used for the serum production is obtained by an extraction method developed by Barnes [7] called “milking”. In this technique, jellyfish tentacles from C. fleckeri are placed on an amniotic membrane that is tensioned over a jar and through subsequent mechanical, chemical or sonic stimulation the nematocysts are prompted to deliver venom through the membrane into the collection jar [7]. Antivenom raised from antibodies against both, milked and native venom, was able to prevent cardiovascular collapse in rats [9]

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Discussion

Conclusion