Antibodies can be highly active and can attack RBCs and bind components of the complement system to cause massive hemolysis of the transfused blood.Patients should ideally receive their own blood or type-specific blood products to minimize the chance of a transfusion reaction. It is also possible to use the patients own blood for transfusion. This is called autologous blood transfusion, which is always compatible with the patient. The procedure of washing a patients own red blood cells goes as follows: The patients lost blood is collected and washed with a saline solution. The washing procedure yields concentrated washed red blood cells. The last step is reinfusing the packed red blood cells into the patient. There are multiple ways to wash red blood cells. The two main ways are centrifugation and filtration methods. This procedure can be performed with microfiltration devices like the Hemoclear filter. Risks can be further reduced by cross-matching blood, but this may be skipped when blood is required for an emergency. Cross-matching involves mixing a sample of the recipients serum with a sample of the donors red blood cells and checking if the mixture agglutinates, or forms clumps. If agglutination is not obvious by direct vision, blood bank technologist usually check for agglutination with a microscope. If agglutination occurs, that particular donors blood cannot be transfused to that particular recipient. In a blood bank it is vital that all blood specimens are correctly identified, so labelling has been standardized using a barcode system known as ISBT 128.
Group C blood is different in that it agglutinates with both A and B. This was the discovery of blood groups for which Landsteiner was awarded the Nobel Prize in Physiology or Medicine in 1930. (C was later renamed to O after the German Ohne, meaning without, or zero, or null.) Another group (later named AB) was discovered a year later by Landsteiners students Adriano Sturli and Alfred von Decastello without designating the name (simply referring it to as "no particular type"). Thus, after Landsteiner, three blood types were initially recognised, namely A, B, and C.Czech serologist Jan Janský was the first to recognise and designate four blood types in 1907 that he published in a local journal, using the Roman numerical I, II, III, and IV (corresponding to modern O, A, B, and AB respectively). Unknown to Janský, an American physician William L. Moss introduced almost identical classification in 1910; but his I and IV corresponding Janskýs IV and I. Moss came across Janskýs paper as his was being printed, mentioned it in a footnote. Thus the existence of two systems immediately created confusion and potential danger in medical practice. Mosss system was adopted in Britain, France, and the US, while Janskýs was preferred in most other European countries and some parts of the US. It was reported that "The practically universal use of the Moss classification at that time was completely and purposely cast aside. Therefore in place of bringing order out of chaos, chaos was increased in the larger cities."