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Synthetic llama antibodies soothe arthritis pain
Climate will suffer if predators are lost Fred Pearce
populations right the way down. And since plants – important carbon sinks – sit at the base of most food chains, any change at the top could affect the overall carbon cycle. Atwood and her team tested the idea in Canada and Costa Rica by temporarily removing fish and insect top predators from ponds, streams and tiny wet ecosystems associated with bromeliad plants. They then logged the impact on the local biomass, including its rate of decomposition – a process which produces emissions. They also monitored how much carbon dioxide was released into the atmosphere. A consistent pattern emerged: CO2 emissions typically grew
FLATTENED forests and melted permafrost boost greenhouse gas emissions – and now it seems the plight of nature’s top predators, too, will speed up the planet’s lurch towards a hotter climate. Mass extinctions of the big beasts of the jungles, grasslands and oceans could already be adding to emissions, according to a new study based on fieldwork in aquatic ecosystems. Equally, saving such species could keep greenhouse gases locked away, raising the possibility of conservationists claiming carbon credits for protecting charismatic predators. “It looks like predators in many types of ecosystems can play a big role in global climate change,” says “Something like removing Trisha Atwood of the University of British Columbia in Vancouver, sharks from the ocean could have a big impact Canada, who led the study. on greenhouse gases” The dramatic impact on ecosystems of losing top predators more than tenfold after the is well known. In the ensuing predators were removed (Nature “trophic cascade”, the animals they feast on proliferate, which in Geoscience, doi.org/kjm). Global climate models do not turn puts pressure on their prey, yet take such impacts into account. and so on. In this way, changes at the top of a food chain destabilise Atwood says the effects could be
Llama-inspired drug relieves arthritic pain ARTHRITIS may have met its match, in the form of the llama immune system. Antibodies similar to ones originally discovered in camels and llamas have helped to heal moderate to severe arthritis in a small trial. The antibodies have inspired the design of a drug, ALX-0061, that blocks a receptor for interleukin 6. This signalling molecule amplifies inflammation, leading to sore and 12 | NewScientist | 23 February 2013
swollen joints. The symptoms ease once the receptor is blocked. In the trial, 24 patients received one of three unchanging doses of ALX-0061 for six months. Another group received a placebo. Sixty-three per cent of those given the drug saw their symptoms practically vanish when measured using a standard metric, the DAS28 scale, which evaluates symptoms in 28 joints. This figure is more than twice the 30 per cent remission rate seen with the current “gold-standard” rival treatment Actemra (tocilizumab). Tocilizumab also targets interleukin 6, but it is based on a
Burrard-Lucas Photography
THIS WEEK
–Guardians of the carbon cycle–
major as freshwater emissions may be on a par with the influence of deforestation, which is thought to account for around 15 per cent of human-caused CO2 emissions. The effect will not always be to increase emissions, however: they may sometimes fall when top predators disappear, according to modelling Atwood carried out alongside the experiments. Either way, she says, the work shows that “something seemingly unrelated, like fishing all the trout from a pond or removing sharks from the ocean, could have big
consequences for greenhouse-gas dynamics”. Other studies hint at similar effects. Christopher Wilmers of the University of California, Santa Cruz, and colleagues showed last year that vanishing sea otters are linked with higher emissions from North American coastlines (Frontiers in Ecology and the Environment, doi.org/khz). With no otters to eat them, sea urchins thrive and gorge on kelp forests – often called the “rainforests of the oceans” – resulting in major CO2 releases. n
normal-sized mammalian antibody. The remission rate was even higher – 75 per cent – for the eight patients given one of the three doses: 3 milligrams per kilogram of body weight administered once every four weeks. “These data suggest that out of every 10 patients, seven to eight could experience rapid, durable responses to their symptoms,” says Josi Holz, the chief medical officer of Ablynx, in Ghent, Belgium, which released its results on 13 February. According to Ed Moses, CEO of Ablynx, it could be the tiny size of the molecule – one-fifth the usual size – that gives it the edge over existing
antibody-based treatments. “It potentially gives far faster and deeper penetration of diseased joints,” he says. Other researchers caution against over-optimism because the trial was short and small. “If the results are repeated in randomised, controlled, double-blinded studies, then they would be very impressive,” says David Scott, chief medical adviser to the UK’s National Rheumatoid Arthritis Society. To take ALX-0061 forward, Ablynx is now looking for a partner to help finance such a larger, decisive trial. Andy Coghlan n
populations right the way down. And since plants – important carbon sinks – sit at the base of most food chains, any change at the top could affect the overall carbon cycle. Atwood and her team tested the idea in Canada and Costa Rica by temporarily removing fish and insect top predators from ponds, streams and tiny wet ecosystems associated with bromeliad plants. They then logged the impact on the local biomass, including its rate of decomposition – a process which produces emissions. They also monitored how much carbon dioxide was released into the atmosphere. A consistent pattern emerged: CO2 emissions typically grew
FLATTENED forests and melted permafrost boost greenhouse gas emissions – and now it seems the plight of nature’s top predators, too, will speed up the planet’s lurch towards a hotter climate. Mass extinctions of the big beasts of the jungles, grasslands and oceans could already be adding to emissions, according to a new study based on fieldwork in aquatic ecosystems. Equally, saving such species could keep greenhouse gases locked away, raising the possibility of conservationists claiming carbon credits for protecting charismatic predators. “It looks like predators in many types of ecosystems can play a big role in global climate change,” says “Something like removing Trisha Atwood of the University of British Columbia in Vancouver, sharks from the ocean could have a big impact Canada, who led the study. on greenhouse gases” The dramatic impact on ecosystems of losing top predators more than tenfold after the is well known. In the ensuing predators were removed (Nature “trophic cascade”, the animals they feast on proliferate, which in Geoscience, doi.org/kjm). Global climate models do not turn puts pressure on their prey, yet take such impacts into account. and so on. In this way, changes at the top of a food chain destabilise Atwood says the effects could be
Llama-inspired drug relieves arthritic pain ARTHRITIS may have met its match, in the form of the llama immune system. Antibodies similar to ones originally discovered in camels and llamas have helped to heal moderate to severe arthritis in a small trial. The antibodies have inspired the design of a drug, ALX-0061, that blocks a receptor for interleukin 6. This signalling molecule amplifies inflammation, leading to sore and 12 | NewScientist | 23 February 2013
swollen joints. The symptoms ease once the receptor is blocked. In the trial, 24 patients received one of three unchanging doses of ALX-0061 for six months. Another group received a placebo. Sixty-three per cent of those given the drug saw their symptoms practically vanish when measured using a standard metric, the DAS28 scale, which evaluates symptoms in 28 joints. This figure is more than twice the 30 per cent remission rate seen with the current “gold-standard” rival treatment Actemra (tocilizumab). Tocilizumab also targets interleukin 6, but it is based on a
Burrard-Lucas Photography
THIS WEEK
–Guardians of the carbon cycle–
major as freshwater emissions may be on a par with the influence of deforestation, which is thought to account for around 15 per cent of human-caused CO2 emissions. The effect will not always be to increase emissions, however: they may sometimes fall when top predators disappear, according to modelling Atwood carried out alongside the experiments. Either way, she says, the work shows that “something seemingly unrelated, like fishing all the trout from a pond or removing sharks from the ocean, could have big
consequences for greenhouse-gas dynamics”. Other studies hint at similar effects. Christopher Wilmers of the University of California, Santa Cruz, and colleagues showed last year that vanishing sea otters are linked with higher emissions from North American coastlines (Frontiers in Ecology and the Environment, doi.org/khz). With no otters to eat them, sea urchins thrive and gorge on kelp forests – often called the “rainforests of the oceans” – resulting in major CO2 releases. n
normal-sized mammalian antibody. The remission rate was even higher – 75 per cent – for the eight patients given one of the three doses: 3 milligrams per kilogram of body weight administered once every four weeks. “These data suggest that out of every 10 patients, seven to eight could experience rapid, durable responses to their symptoms,” says Josi Holz, the chief medical officer of Ablynx, in Ghent, Belgium, which released its results on 13 February. According to Ed Moses, CEO of Ablynx, it could be the tiny size of the molecule – one-fifth the usual size – that gives it the edge over existing
antibody-based treatments. “It potentially gives far faster and deeper penetration of diseased joints,” he says. Other researchers caution against over-optimism because the trial was short and small. “If the results are repeated in randomised, controlled, double-blinded studies, then they would be very impressive,” says David Scott, chief medical adviser to the UK’s National Rheumatoid Arthritis Society. To take ALX-0061 forward, Ablynx is now looking for a partner to help finance such a larger, decisive trial. Andy Coghlan n