Landsteiner's rule is applicable to which blood group system?

Landsteiner's rule states that individuals with a particular blood type will naturally produce antibodies against the antigens they do not possess. This principle is clearly applicable to the ABO blood group system. For example, a person with blood type A has A antigens on their red blood cells and will produce antibodies against B antigens (anti-B antibodies). Similarly, individuals with blood type B have B antigens and produce anti-A antibodies. Blood type O, which lacks both A and B antigens, produces both anti-A and anti-B antibodies. This characteristic is fundamental to blood compatibility and transfusion practices, emphasizing the importance of Landsteiner's rule in understanding ABO blood group reactions.

In contrast, other blood group systems such as Rh, Kell, and Duffy do not follow the same pattern as outlined by Landsteiner's rule. These systems may involve more complex interactions and may not necessarily result in the predictable production of antibodies against non-self antigens in the same direct manner as ABO antigens.