Can We Create Universal Blood?

In 1959 British Medical Journal reported on mysterious condition never seen before where several patients with type A blood showed signs blood type changing suddenly with red blood cells temporarily expressing B blood type antigen reversing to normal over time.

In 1972 detectives investigating dismembered body recovered from River Thames discovered forensic anomaly where one body part showed O type blood while different part submerged longer identified as B type blood creating apparent contradiction resolved by acquired B phenomenon.

Scientists realized common link between acquired B cases not genetic change nor accidental blood introduction but work of bacteria specifically certain bacterial enzymes cleaving or altering blood antigens turning one blood type into another revealing blood types not immovable.

Every two seconds someone in United States needs blood yet only 38 percent population eligible to give blood or platelets with less than 10 percent actually donating and only 7 percent having universal donor O negative blood creating severe shortage.

ABO blood group system determined by presence of antigens A and B carried on red blood cell surface where individuals possess type A B AB or O blood with O meaning neither A nor B antigens present only H antigen serving as blank base.

Rh or Rhesus system works similar to ABO where missing most important Rh antigens means negative blood type with Rh negative recipients only receiving Rh negative blood while Rh positive recipients accepting either creating eight common blood types combined with ABO.

O negative blood type does not produce incompatibility reaction in any eight common blood types making it universal donor extremely valuable in medical situations because sudden accidents lack time to assess patient blood type as they bleed out making O negative safe bet.

In 1982 scientists first experimented with turning A B or AB blood into O blood believing they could convert red blood cells by removing extra sugar chains with appropriate enzyme using alpha galactosidase derived from green coffee beans as only commercially available option.

Coffee bean alpha galactosidase came with several problems requiring low pH 5.7 for conversion not ideal for red blood cells preferring pH 7.4 plus huge enzyme amount required making process inefficient uneconomical and most significantly only cleaved B antigen not A.

Determined to find missing piece scientists 2007 began hunt for brand new enzyme looking where acquired B phenomenon alluded to world of microbes reasoning if gut or river bacteria could accidentally transform blood types right enzyme could be found among millions of microbes.

Although river bacteria enzyme could cleave A antigen it was wildly inefficient with A-cleaving enzyme 30 times less efficient than B-cleaving enzyme requiring 60 milligrams enzyme per unit red blood cells for A to O conversion versus only 2 milligrams for B to O.

Sixteen years after 2007 discovery scientists became armed with new technology metagenomic analysis allowing assessment of genetics of everything in sample at once looking for desired genes enabling screening 20,000 bacterial samples from human gut for efficient A-antigen cleaving enzyme.

When researchers tested two thousand samples at first nothing promising appeared but when they tested two resulting enzymes at once A antigen came right off as deacetylase and galactosaminidase from bacteria Flavonifractor plautii working together provided solution eluding scientists for decades.

High efficiency of Flavonifractor plautii enzymes means only tiny amounts needed as little as 1 milligram per unit red blood cells versus 60 needed in previous studies allowing cost-effective addition to already existing routines of blood collection processing and storage with major implications.

Typing blood could become obsolete and everyone who donates could become universal donor where people with more rare blood types will not wonder if right blood available to them with countless lives saved though more work needed ensuring complete antigen removal and no adverse effects.