The story of how a worm turned into a bringer of med­i­cal mir­a­cles Worm blood could save lives, help trans­plant pa­tients

Kuwait Times - - HEALTH & SCIENCE -

For cen­turies, the only use hu­mans found for the lug­worm-dark pink, slimy and ined­i­ble-was on the end of a fish hook. But the in­ver­te­brates' un­ap­pre­ci­ated sta­tus is about to change. Their blood, say French re­searchers, has an ex­tra­or­di­nary abil­ity to load up with life-giv­ing oxy­gen. Har­ness­ing it for hu­man needs could trans­form medicine, pro­vid­ing a blood sub­sti­tute that could save lives, speed re­cov­ery af­ter surgery and help trans­plant pa­tients, they say.

"The he­mo­glo­bin of the lug­worm can trans­port 40 times more oxy­gen from the lungs to tis­sues than hu­man he­mo­glo­bin," says Gre­gory Ray­mond, a bi­ol­o­gist at Aquas­tream, a fish­farm­ing fa­cil­ity on the Brit­tany coast­line. "It also has the ad­van­tage of be­ing com­pat­i­ble with all blood types." Ray­mond and his team, which spe­cial­izes in fish egg pro­duc­tion, joined forces with biotech firm He­ma­rina in 2015 in the hope of se­cur­ing a re­li­able means of lug­worm pro­duc­tion.

The fa­cil­ity now churns out more than 1.3 mil­lion of the crea­tures each year, each pro­vid­ing tiny amounts of the pre­cious he­mo­glo­bin. "We started ba­si­cally from zero. Since the worm had never been stud­ied, all pa­ram­e­ters needed in­vent­ing from scratch, from feed­ing to wa­ter tem­per­a­ture," says pro­ject re­searcher Gwen Her­ault. Med­i­cal in­ter­est in the lug­worm-Areni­cola ma­rina-dates back to 2003, when the out­break of mad-cow dis­ease in Europe and the world­wide HIV epi­demic be­gan to af­fect blood sup­plies.

The prob­lem was that an­i­mal he­mo­glo­bin's, as a sub­sti­tute for the hu­man equiv­a­lent, can cause al­ler­gic re­ac­tion, po­ten­tially dam­ag­ing the kid­neys. In lug­worms, though, he­mo­glo­bin dis­solves in the blood and is not con­tained within red blood cells as in hu­mans-in other words, blood type is not an is­sue­and its struc­ture is al­most the same as hu­man he­mo­glo­bin. In 2006, the worm's po­ten­tial was val­i­dated in a ma­jor study. Sci­en­tists at Roscoff, close to Plomeur, ex­tracted and pu­ri­fied he­mo­glo­bin from lo­cal-caught lug­worms and tested it on lab mice.

The ro­dents were fine and showed no sign of the im­mune re­sponse that dogged other an­i­mal sub­sti­tutes. If proven safe for hu­mans, the re­searchers said, the worms' oxy­gen-rich blood could tackle sep­tic shock-a crash in blood pres­sure that can cause fa­tal mul­ti­ple or­gan fail­ure-and help to con­serve or­gans for trans­plan­ta­tion. Clin­i­cal tri­als of the blood prod­uct be­gan in 2015. Lug­worm he­mo­glo­bin was used last year in 10 hu­man kid­ney trans­plants at a hospi­tal in the west­ern French city of Brest and 60 pa­tients are cur­rently en­rolled in tests of the blood prod­uct across France.

Male or fe­male?

The se­crets of lug­worm he­mo­glo­bin lie in its abil­ity to sur­vive in ex­treme con­di­tions, bur­row­ing into sand at the edges of the tide. The worm grows to about 25 cen­time­ters in length and has sev­eral bushy ex­ter­nal gills along its body. At high tide, sub­merged in wa­ter, the worm builds up stocks of oxy­gen that, as­ton­ish­ingly, al­low it to sur­vive more than eight hours out of the wa­ter at low tide. Any­one who has walked along a sandy beach at low tide will see ev­i­dence of lug­worms, from the tiny coiled casts of sand they throw up from their bur­row, 10 cms be­low the sur­face. But, apart from an­glers who dig up the crea­tures for bait, lug­worms are rarely seen-and breed­ing them is a novel chal­lenge. "The main dif­fi­culty is work­ing with a small an­i­mal that lives its life hid­den," ex­plained Ray­mond. Aquas­tream strug­gled at first with ba­sic rear­ing prob­lem­sin­clud­ing how to tell a male lug­worm from a fe­male. Af­ter nine months of test­ing, "50 per­cent of adult worms sur­vived and a good deal of them pro­duced eggs," said Her­ault.

The lar­vae start out around 1mm in length and the worms are trans­ported to He­ma­rina's test­ing site once they reach 5mm.Aquas­tream di­rec­tor Nathalie Le Rouilly said that her firm's col­lab­o­ra­tion with He­ma­rina could pro­vide the world of med­i­cal science with a sus­tain­able sup­ply of the worms. "There is nowhere else in France or the world that has the ca­pac­ity to pro­duce lug­worms in a con­trolled en­vi­ron­ment to en­sure a sup­ply of their he­mo­glo­bin," she says.

Sci­en­tists are ex­cited by the po­ten­tial of lug­worm he­mo­glo­bin-al­though they also point to a rig­or­ous test­ing pro­ce­dure be­fore the mol­e­cule can be cer­ti­fied as safe and ef­fec­tive for hu­mans. "The prop­er­ties of ex­tra­cel­lu­lar he­mo­glo­bin ex­tracted from the lug­worm could help pro­tect skin grafts, pro­mote bone re­gen­er­a­tion and lead to univer­sal blood," says Ray­mond. If this vi­sion turns real, lug­worm blood may also al­low donor or­gans to live longer out­side the bodies, po­ten­tially help­ing thou­sands of re­cip­i­ents each year. And, one day, freeze-dried lug­worm blood could be a cru­cial backup for stan­dard blood sup­plies-a boon in com­bat zones or dis­as­ters. — AFP

TOKYO: A hump­head wrasse, trans­ported from Ja­pan's south­ern is­land of Ok­i­nawa, swims with other trop­i­cal salt­wa­ter fish on dis­play in a tank for the Sony Aquar­ium 2017 ex­hi­bi­tion in Tokyo. — AFP

PLOEMEUR: An em­ployee of Aquas­tream com­pany presents a marine worm, in Ploemeur, west­ern France. — AFP pho­tos

PLOEMEUR: An em­ployee of Aquas­tream com­pany looks at marine worms through a mi­cro­scope, in Ploemeur, west­ern France.

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