7 - Obs - Red Blood Cell Isoimmunisation Flashcards
definition - RBCI occurs when ? mounts ? response against ? on ? RBCs that are entering ? circulation. Resulting with ? that cross the ? and cause fetal RBC ?
mother immune antigens fetal maternal Abs placenta destruction
Blood Groups
Blood classified according to ??? and ? genotype
Most signif ? is D gene. D dom to d, only indiv who are ?? or ?? express the D antigen and are D Rh ?ve. ‘dd’ indiv are D Rh ?ve, and their immune system will ? D antigen as ? if exposed
ABO Rh isoimmunization DD Dd \+ - recognize foreign
Sensitisation
Small amounts of fetal ? cross placenta to ? circ during ?
pregs, esp at ?. If fetus is D Rh +ve and mother D Rh –ve, mother will ? ? ? creating anti-D ?.
blood maternal uncomplx delivery mount immune response Abs
Haemolysis
Immunity is ?, if mother’s immune system again exposed to ?, large no’s Abs ? created, cross ? and bind to ? RBCs – destroy in the fetal ?-endothelial ?. Can cause ?
anaemia and death, called Rhesus haemolytic disease. Other antigens can have similar effects: anti-? and anti-?, esp after ?.
permanent antigen rapidly placenta fetal reticulo-endothelial system haemolytic c Kell transfusion
Potential events that cause sensitisation of maternal blood to fetal blood antigens….
- ??? or ???? after miscarriage
- ? pregnacny
- ? bleeding <12 weeks or if ?
- External ? ?
- Invasive ? procedure eg amniocentesis or ? ? sampling
- ? death
- delivery
TOP or ERPC ectopic vaginal heavy cephalic version uterine chorionic villus sampling intrauterine
Prevention: Using Anti-D
Prod of ? Anti-D prevented by admin of ? anti-D to ?. Mops up ? RBCs by binding their ?, preventing ? by maternal immune system. If both parents known Rh ?ve, fetus must also be Rh –ve so ?. Anti-D still given if the partner known to be Rh –ve due to possibility of non-?. Anti-D pointless if maternal anti-D is already present from prev ?.
maternal exogenous mother fetal antigens recognition - unaffected paternity sensitisation
Prevention of Rhesus disease.
Antenatal - Anti-D given to all Rh ?ve women at ?weeks. Also given within ?h of any ? event
Postnatal - Neonates ? ? checked and if Rh ?ve, anti-D given to ? within 72h of ? - Kleihauer test assesses no of ? cells in maternal circ, done within ?h of birth to detect larger ? haemorrhages needing larger doses of ? to mop up. Anti-D not given if fetus Rh?ve.
- 28 72 sensitising blood group \+ mother delivery feto 2 fetomaternal Anti-D -
