A Collaborative Study to Establish the Second Korean National Reference Standard for Snake Venom

Abstract

In 2015, a candidate for the second national reference standard (NRS) of Gloydius snake venom was produced to replace the first NRS of Gloydius snake venom. In the present study, the potencies of the candidate were determined by a collaborative study, and the qualification of the candidate was estimated. The potencies of the candidate were determined by measuring the murine lethal titers and lapine hemorrhagic titers of venom against the regional working reference standard (RWRS) for antivenom using the methods described in the previous report for the first NRS of Gloydius snake venom. Three Korean facilities contributed data from a total of 30 independent assays. Subsequently, two foreign national control research laboratories contributed to this collaborative study. The results were calculated using the Reed-Muench method for lethality and determined using a mixed-effects model for hemorrhage. The general common potencies of the lethal and hemorrhagic titers were obtained from the results of the 30 tests performed at three Korean facilities. The results are expressed in micrograms for 1 test dose (TD) with a 95% confidence interval as follows: a lethal titer of 90.13 μg/TD (95% confidence interval = 87.39~92.86 μg) and a hemorrhagic titer of 10.80 μg/TD (95% confidence interval = 10.46~11.14 μg). In addition, the candidate preparation showed good quality evaluation according to the results of the quality estimation of the candidate and is judged to be suitable to serve as the Korean NRS for snake venom. In conclusion, the second NRS of Gloydius snake venom was established in this study and will be used for national quality control, including a national lot release test of Korean antivenom products.

Standardization of the first Korean national reference standard for snake (Gloydius brevicaudus) antivenom

“…Regional reference standard materials also could be used when countries within a region share a similar distribution of venomous snakes [13]. The candidate for the first NRS for Gloydius snake antivenom assessed for quality in this study was raised against the venom of Gloydius brevicaudus, which was used for establishment of the second NRS for snake venom [12]. This species is widely distributed throughout Korea.…”

“…The real-time stability tests were performed at Korea Vaccine Co., Ltd. where the candidate vials in triplicate were maintained at − 20°C for 0, 3, 6, 9, and 12 months. The control limits for monitoring the stabilities of potencies were set up in the range of 80-120% of the general common potencies, complying with the quality standard of other blood derived products [12]. The lower control limits (LCLs) were 2480 U/ml in the anti-lethal titer and 2400 U/ml in the anti-hemorrhagic titer.…”

“…011201) established regionally in Japan, China, and Korea [10] using the Korean national reference standard (NRS) for Gloydius snake venom as the test snake venom, which was established individually in 2004 [11]. In 2017, the second NRS for Gloydius snake venom was established to replace the first NRS for Gloydius snake venom [12]. In connection with the second NRS for Gloydius snake venom, a candidate for the reference standard for Gloydius snake antivenom was produced for the first time as the Korean national reference in 2017.…”

Adverse Reactions after Administration of Antivenom in Korea

“…One unit of antivenom is an anti-lethal or anti-hemorrhagic titer that neutralizes one test dose of venom. The lethal and hemorrhagic titer of the national reference standard of Gloydius snake venom is 90.13 μg and 10.80 μg per 1 test dose, respectively [ 47 ]. One vial of Kovax ® antivenom contains more than 6000 anti-lethal and anti-hemorrhagic units, respectively.…”