The life-saving role of blood transfusions in treating blood disorders

The National Blood Week has just ended so I thought it an appropriate moment to reflect upon the central and often under-appreciated life-saving role transfusion plays in the management of aplastic anaemia and so many other blood disorders. Nobody really likes having to receive transfusions so no wonder they are not always given the respect they deserve. There is also the awareness that transfusions potentially have risks that careful and precise processes in collection and delivery are in place to minimise. The publicity given to the Government inquiry into infected blood and blood products particularly since 1970, must also cause worry even for some who received blood transfusions only in more recent times. In this brief note I want to give you my personal as well as professional view on the fantastic work the four NHS Blood Transfusion Services of the UK do in providing the life-giving products volunteers donate and the way in which these products are delivered as safely to patients. Of necessity my comments relate to the service in England.

How transfusions evolved over time 

The earliest blood transfusion in England is usually attributed to a Cornishman working in Oxford in the 17^thcentury, Richard Lower (I was a very junior doctor on a ward in the Radcliffe Infirmary named after him). It is not quite clear whether this donation, given directly from a donor’s vein to the recipient’s, was a first successful transfusion. Not much progress was made until the beginning of the 20^thcentury when the ABO blood groups were identified by an Austrian scientist Karl Landsteiner and their significance in avoiding the often fatal reactions to random donations became apparent. By the end of the First World War, at the beginning of which there was little or no transfusion service,  the first primitive blood banks were established using bottled donations mainly thanks to the effort of an American physician, Oswald Robertson, who was sent to advise and work with at a British Army Casualty Clearing Station. After that War donors were mainly identified in families in a service run by the Red Cross. Perhaps the most influential step in providing the amazing and safe service we have now was the foresight of a Camberwell assistant librarian working as a Red Cross volunteer, Percy Oliver, who established the totally altruistic, anonymous, unremunerated volunteer donation system we have now.

It began with milk bottles

Between the wars, basic blood transfusion services were managed regionally or by hospitals themselves but the impending conflict led Janet Vaughan, a haematologist at the Postgraduate Medical School, Hammersmith Hospital to set up on her own initiative a “National” transfusion service in London using modified milk bottles for banking the donations.  Dame Janet, as she became,  was the founding head of the Department of Haematology at Hammersmith Hospital before she became Principle of Somerville College Oxford and her legacy of an  outstanding blood transfusion unit  in the Department was a major contribution enabling us in 1971 to set up a transplant unit specialising in bone marrow failure diseases and so to the founding of the Marrow Environment Fund , the forerunner of the AAT.

In 1946, just as the NHS was about to come into being, the various blood collecting centres were brought together under the National Blood Service banner but remained firmly regionally based  until 1991 when the regions in England were united under central direction, a move associated with a great deal of controversy such that the government of the time established a sort of independent referee group called the National Blood Users Group (NBUG), of which I was the first chairman. Inevitably the NBUG was perceived in some quarters as a tool of the government so I’m not sure how much good we did in helping bring about what ultimately became a truly excellent National Blood Transfusion Service, a Service which continues to evolve, again often with some excitements as rationalisation leads to rearrangement of roles for individual collecting/processing centres. The NBUG has gone on to be an important group advising on the proper use of blood products, especially for surgical and emergency use.

Two technical innovations revolutionised the way in which blood was collected. One was the introduction of the familiar plastic blood bags of today in place of the glass successors of the milk bottles. The other was the collection of special products, particularly platelets, by apheresis which means that significant numbers can be collected from one donor without the need to pool donations. The technique has of course also greatly improved the way in which stem cells may be collected for transplants, reducing (but not completely replacing) the need for the somewhat cumbersome process of bone marrow collection.

Collecting bone marrow 

Successful bone marrow transplantation for aplastic anaemia and leukaemia was achieved in Seattle, USA, in 1968 by Donnall Thomas and his team using the newly identified tissue matching methods. The potential had been recognised in many other centres including the Westminster Hospital, London, where I was lucky enough to be a clinical student at the time.

At the Westminster Children’s Hospital, a child, Anthony Nolan, was admitted with a rare blood disorder for which no matched relative donor was available. His mother Shirley together with Dr David James from the Westminster Hospital set up, in 1974, the Charity which bears his name today to create a registry of volunteer bone marrow donors. In 1977 the first unrelated transplants for aplastic anaemia in the UK using donors found by the Anthony Nolan Trust were carried out in the Hammersmith unit. (The amazing globalization of the Anthony Nolan initiative requires another chapter.) The National Blood Transfusion Service joined the Anthony Nolan Trust in registering volunteer donors and the collection of cord blood donations. In 2005 the blood transfusion and transplant services were brought together in England as the NHS Blood and Transplant (NHSBT) with responsibilities for encouraging and processing donations of blood, organs and stem cells.

Are blood transfusions safe?

In this potted history of blood transfusion service, I have yet to mention the safety of blood transfusion. From the earliest days it was known that diseases could be transmitted by blood transfusion and donors were screened for known risks as well as being asked not to donate if they might have been exposed to infectious diseases or malaria.  Nowadays there is a huge battery of tests which screen out potential infectious risks and provide meticulous identification of the donor blood group systems. Tragedies occurred in the past when unrecognised or unidentifiable agents entered the service, most dramatically and tragically AIDS before it was known that a virus, HIV< was the cause. The disaster struck most widely in people who received blood products from multiple pooled donations where blood from one infected donation contaminated the whole batch which was then used for many recipients. This was a special sadness for the haemophiliac community. Of course, once HIV was identifiable all donations were screened as is the case for the various hepatitis viruses and a host of rarer possible disorders. Traceability and record keeping are two essentials of the blood transfusion service and every donation can be identified if a problem arises. Any reactions, including near misses and trivial febrile reactions are now sent to an organisation, set up by the Royal College of Pathologists in 1996 and reporting to the MHRA, called Serious Hazards of Transfusion (SHOT) which publishes an annual report. In the most recent reports two definite cases of transmission of rare hepatitis viruses were identified both in severely immunocompromised patients who received large quantities of blood product from a recently infected donor. In another recipient, a single donation from the same infected donation produced no problem because the amount of virus transmitted was too low.

Over two and a half million blood products are transfused every year in England, so it is reasonable to state that the risk of virus infected blood is less than 1 in a million and probably less, thanks to the vigilance of the NHSBT.

Numerically greater risks come from human error in the form of transfusion of wrong blood for the patient, blood at the wrong time (too much or too late) and very rarely infection of the collected blood. Well recognized but rare reactions do occur as a result of antibodies or unidentified antigens in the donation.

In summary, the risk of receiving virus infected blood nowadays is vanishingly small (though some transmissions occurred from blood given many years ago where the virus lurks on in the recipient for decades or more). Great vigilance is needed to avoid mistakes in the giving of blood – it would be sensible for recipients to know if possible their own blood groups and to check what they are receiving (not all transfusions have to be of the recipient’s group, for example group O Rhesus negative is very valuable because it may almost be considered a universal product).  The remaining reactions result mostly from immune reactions related to minor blood group or tissue antigens. These are identifiable on red cells but much more difficult to find on platelets and on these the culprit may be more closely linked to tissue antigens than the  blood group antigens, hence the need for tissue (HLA) matched platelets for recipients with repeated reactions. The frequency of both HLA and blood group antigens varies between different ethnic communities and whilst the mainly Caucasian panels of the bone marrow registries and the donor pools of the blood transfusion service provide donors for the great majority of Caucasian recipients they may find it harder to find a perfect match for other groups. The NHS BT service is running a big campaign (The Blood Donation Forum) to encourage donations from all ethnic groups to meet this challenge, a campaign the AAT strongly supports.

Looking back I realise what an amazing progress has been made during my professional life in the provision of blood and blood products, from the days when we gave blood transfusions from glass bottles via rubber tubing and doctor sharpened needles - to the wonderful array of products available now, collected in safe and controlled conditions, and given through disposable and (reasonably!) comfortable access methods.

This must be one of great advances over the 70 years since the founding of the NHS to have benefited so very many thousands of  people safely and efficiently. It was certainly central to my own work in aplastic anaemia and stem cell transplantation. So, thanks to all donors and the patience of the patients!

Prof Ted Gordon-Smith

June 2019