Blood transfusion is essential in both planned and emergency medical interventions. It will therefore come as no surprise that blood donors help and save tens of millions of lives every year. Although there are accounts of the successful transfusion of blood before the 20th century, these early attempts at blood transfusion often resulted in the death of the patient. It was not until the beginning of the twentieth century when Karl Landsteiner first discovered human blood groups (the ABO system), and the adverse effects associated with mixing blood from incompatible donors and recipients, that blood transfusion started to become safer. Karl Landsteiner, along with Alexander Wiener, went on to discover Rhesus blood groups, which together with the ABO system are still used today to check the compatibility of donor blood and recipients. So it is appropriate that the birthday of Karl Landsteiner is also World Blood Donor Day, which serves to raise awareness of the need for safe blood and blood products and to thank voluntary blood donors.
Further developments in the 20th century improved the quality and availability of blood and blood products, for example with the introduction of the now familiar plastic blood bags which replaced less durable glass bottles, and the development of suitable preservatives such as anticoagulants. So that the donated blood is more suited to specific patient populations, blood is often separated into various components such as red blood cells, plasma and platelets. In fact, with appropriate medical devices, the separation of desired blood components can be carried out during the blood donation process itself, and as described for example in WO/2014/144138, medical devices integrated into blood donation chairs may make the blood donation process easier, especially in mobile settings. Further, as separation of blood components often increases the number of transfusable units from a single donation, and as unharvested components can be returned to the donor, the donor may be able to donate more frequently.
Safety too has come a long way since the start of the 20th century. As well as determining the ABO and Rhesus groupings, donated blood and blood products are tested for transmissible pathogens. Nevertheless, in rare cases, blood transfusion can still transmit infection or cause an adverse immune reaction in the recipient. Therefore, there is interest in stripping donated blood of undesirable components, for example as described in WO/2020/034042 to create "universal blood". In addition, the development of quicker, more accurate and cheaper testing will also help, and may disproportionately benefit low-to-middle income countries where widespread robust testing is often not available.
Shortages in blood supplies, along with the small risks associated with blood transfusion, have also fuelled the development of blood substitutes. This includes the latest generation of artificial blood, containing engineered constituents capable of gas exchange in a similar way to haemoglobin in red blood cells, for example based on work described in WO/2018/167469. Further, there has been much interest in the "holy grail" of generating unlimited quantities of blood products by converting and expanding blood stem cells.
Innovation that helps contribute to the global demand for safe blood is likely to come from many fields, and the patent system is of course one way that such innovation can be encouraged and rewarded. However, at least for now, blood donors continue to be essential for effective health care systems. So if you can, do consider regularly donating blood.
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