Within the other end of the age spectrum, and as discussed earlier, neonates and young children are generally considered poor responders to RBC antigens. discuss some practical approaches to prevent alloimmunization in individuals who may be prone to alloantibody development. process, a responder is definitely defined as any individual who has become alloimmunized to at least one non-ABO antigen. This selective model also indicates the living of a distinct group of individuals incapable of responding to non-ABO antigens despite repeated RBC exposures (a group typically dubbed non-responders). An alternative model posits that there is no specific selectivity and that virtually all individuals are capable of becoming alloimmunized to at least one non-ABO antigen upon exposure. Consequently, with this second model, responders are typically viewed as individuals who exuberantly develop alloantibodies following transfusion, sometimes after very few antigenic exposures. Are either of these models or meanings completely adequate to match alloimmunization patterns reported in the medical literature? You will find certainly data to support the notion that only selected subsets of individuals are capable of responding to non-ABO antigens. For instance, there are several studies which demonstrate that human being leukocyte antigen (HLA) class II restriction is an important determinant of whether individuals can present antigens such as K, Jka, and Fya (this will become discussed in greater detail later with this paper). There are also reports indicating groups of individuals who by no means appear to develop RBC alloantibodies despite hundreds of exposures. Consequently, at least for some antigens, a selective responder model seems appropriate. However, this definition does not seem to be readily relevant to all antigens. As an example, large numbers of Rh(D)-negative individuals (in some cases upwards of 85C90% of subjects) have been noted to develop anti-D following exposure. Moreover, both clinical studies and anecdotal observations suggest that within groups of alloimmunized individuals SAG hydrochloride you will find folks who are multiply alloimmunized, sometimes developing C more than 5 alloantibodies. As such, these second option observations lend some credence to the idea that: i) selectivity may not apply to every blood group antigen and ii) you will find subsets of individuals even within the alloimmunized organizations whose ability for developing alloantibodies may surpass even that of a typical responder. Rabbit Polyclonal to ZC3H8 Given the above considerations, the ideal definition of a responder is likely one which incorporates aspects of both of the earlier frameworks (and is somewhat more expansive in its terminology). As shown in figure ?number1,1, we propose a hypothetical magic size that categorizes transfused individuals in one of three ways: i) non-responders (we.e., individuals who by no means develop any alloantibodies despite repeated exposures); ii) responders (i.e., individuals who develop 1 alloantibody with one or more exposures), and iii) hyper-responders (i.e., individuals who develop 1 alloantibody with one or more exposures). At present, we believe that there are some clinical data assisting such a model SAG hydrochloride system. Below, we will more thoroughly review SAG hydrochloride the studies which led to our creation of this model structure. Nonetheless, it will be important for the transfusion medicine community to continue to perform studies to more fully validate the ideas above, particularly concerning the living of a hyperresponder human population. Open in a separate windowpane Fig. 1 A proposed model for defining the responder phenotype. Red bag icons symbolize RBC transfusions. Y represents alloantibodies; different colours symbolize alloantibodies with different specificities. Incidence of Minor RBC Antigen Alloimmunization in Various Clinical Scenarios With this section,.