New treatment for one of world’s deadliest snakebites created using human blood

Cocktail of antibodies created to neutralise venom could be safer and more effective than current therapies, scientists say

Widely regarded as one of the world’s deadliest snakes, a bite from a black mamba once meant certain death or a complicated and expensive treatment derived from horses blood.

But using substances extracted from human blood samples, scientists have been able to treat mice infected with its deadly venom.

As a result they are now hoping that they will be able to create a new treatment to neutralise various types of snakebite and save thousands of lives.

Around 5 million people every year are bitten by snakes resulting in up to 150,000 fatalities. Others are left permanently disabled.

As most of those take place in poorer parts of the world, pharmaceutical companies are less likely to invest in treatment for them.

Setting out to improve this situation professor Andreas Hougaard Laustsen and his international research team decided to start with the deadly black mamba.

Feared by residents of the African savannah, the creature produces a potent venom which affects the human nervous system and can kill within hours.

Although they can be treated with antivenoms, those currently in use are typically derived from the blood of horses, which have previously been made “hyperimmunised” by injecting them with small amounts of venom.

This produces antibodies in their blood that can be extracted and used to combat the effects of the venom in humans.

We hope that this will pave the way for bringing a therapy to many of the snakebite victims living in impoverished regions in the developing world who have been neglected for so many years

Professor Andreas Hougaard Laustsen

While these treatments work, they are expensive and come with a variety of side effects including so-called “serum sickness” and allergic reactions.

Professor Laustsen who is based at the Technical University of Denmark, reasoned that better results could be achieved using human antibodies.

Rather than injecting humans with snake venom to produce the correct antibodies – a technique that has been attempted by various enthusiastic amateurs – the scientists developed a lab-based alternative.

After scanning a “library” containing human antibody genes collected from blood cells, they then screened the antibodies for ones capable of fighting mamba toxins.

Once they had identified the correct genes, they inserted them into cells that were turned into tiny factories to churn out large amounts of the antibodies.

"The leap forward in our experiments is that we used a biotechnological method to find and then propagate human antibodies in the laboratory to enable use in the treatment of experimental black mamba envenoming,” said Prof Laustsen after results of the study were published in the journal Nature Communications.

“The method we employed can be used to discover human antibodies in the lab by simulating of the human immune system, so we can avoid injecting patients with snake venom to raise antibodies by immunisation.”

The antibodies that resulted from this process were then mixed into a cocktail that was administered to mice, a treatment that halted the neurotoxic effects of mamba venom. The researchers said that while these results are promising, it will likely be years before they are widely applied to treat snakebites.

“Before clinical testing of the antivenom on humans will make sense, it is relevant to develop more antibodies for the antivenom to give it a broader spectrum against several types of snake venom," Prof Laustsen said.

His team nonetheless hope that having done this they can assemble a treatment that can be given by doctors to treat a wide range of bites, even when the identity of the snake is unknown.

Professor Laustsen said these results demonstrated that antivenoms can be made safer, and the team suggested that with development their technique could be a cheaper option for developing countries.

“We also hope that this will pave the way for bringing a therapy to many of the snakebite victims living in impoverished regions in the developing world who have been neglected for so many years,” he added.