Rh(D) negative patients will not have anti-D in their plasma. Anti-D is not a naturally occurring antibody like those in the ABO blood group. An Rh(D) negative patient would have to be exposed to the antigen to create this antibody. This is called alloimmunization. Therefore we refer to anti-D as an allo-antibody, not naturally-occurring antibody. For example Rh(D) negative mothers are given antepartum rhogam to avoid alloimmunization from the Rh(D) positive baby during excessive fetomaternal hemorrhage. The rhogam basically tricks the moms immune system into not creating a true anti-D. Otherwise there will be future miscarriages with Rh(D) positive babies.
Oh dude, I appreciate the effort but I wish you'd collaborated with a transfusion specialist or scientist on this video. The reason you can give O positive in an emergency where Onegative stock needs to be conserved is because people don't form allo anti D until after they have been exposed to another person's red cells. This might be by a previous blood transfusion or pregnancy for example. If you give Opos to an Rh negative person in a trauma it is very likely they will form all anti D in the days to weeks after the emergency transfusion but atleast you got them through the first event and can manage the haemolysis of the donated red cells as it happens. With plasma and cryoprecipitate you can basically ignore Rh status of the donor as all donors are screened for the presence of anti D antibodies as part of the donation process. If they are positive for anti-D that plasma is sent for fractionation to become Rh D immunoglobulin for injecting D negative mothers after birth of Rh pos babies.
The reason blood bank gives O Neg vs O Pos in emergency situations is to conserve O Neg units for females of child bearing age and Rh Neg patients. We have to prevent Rh negative females from forming an immune Anti-D. Also, there is always a shortage of O Negative units. Males > 18 and females >50 years old a always get O Pos and females
Absolutely. Thanks for sharing the insight. Yeah O negative can be difficult to keep in supply in quantities needed and fortunately we have a lot of available options for people to get O pos and not really with much consequence in MTP.
