ABO blood group system A and B antigens, but contains anti-A and anti-B. The following year, his students Adriano Sturli and Alfred von Decastello discovered the fourth type (but not naming it, and simply referred to it as "no particular type”). In 1910, Ludwik Hirszfeld and Emil Freiherr von Dungern introduced the term 0 (null) for the group Landsteiner designated as C, and AB for the type discovered by Sturli and von Decastello. They were also the first to explain the genetic inheritance of the blood groups.) Czech serologist Jan Janský independently introduced blood type classification in 1907 in a local journal. He used
Blood transfusion by using blood type testing to identify a less scarce alternative. Jehovah's Witnesses object to blood transfusions due to their belief that blood is sacred. Although there are clinical situations where transfusion with red blood cells is the only clinically appropriate option, clinicians look at whether alternatives as feasible. This can be due to several reasons, such as patient safety, economic burden or scarcity of blood. Guidelines recommend blood transfusions should be reserved for patients with or at risk of cardiovascular instability due to the degree of their anaemia. In these cases parenteral iron is recommended. Thus far, there are