Benign Hematology Flashcards
Time frame of delayed hemolytic transfusion reaction (DHTR)?
5-10 days
What happens to reticulocytes in a DHTR? Is COOMBS positive or negative?
decreased, positive
3 features of acute hyperhemolysis
- destruction of recipient and donor RBC
- low retics
- negative COOMBS
Treatment for pure red cell aplasia from parvovirus?
supportive. may require IVIg. typically resolves in few days to weeks
Parvovirus binds to _ antigen on RBC to cause RBC lysis.
P antigen
RBC antigens features?
1. Kell
2. Duffy
3. Kidd
4. Rh
- determine ABO type and is MC target for autoimmune and alloimmune lysis
- Malarial Plasmodium receptor target
- on membrane of RBC and kidney; urea transporter
- serves as ammonium transporter
MC cause of OM in sickle cell pts?
salmonella. (staph aureus in general pop)
Why is meperidine CI in SCD?
causes seizures
Asplenia vaccine recommendations?
- Neisseria meningitidis
- Strep pneumoniae
- Haemophilus infuenza
- seasonal flu and hep B
Preferred iron formulation in pregnancy?
Iron sucrose (venofer) and sodium ferric gluconate (ferrlecit)
What is methemoglobin (Hb M)?
Methemoglobin is a form of hemoglobin that has been oxidized, changing its heme iron configuration from the ferrous (Fe2+) to the ferric (Fe3+) state. Unlike normal hemoglobin, methemoglobin does not bind oxygen and as a result cannot deliver oxygen to the tissues.
Normal arterial pO2 and cyanosis?
methemoglobinemia with Hb M >10%. when > 40% seizures, coma, death. treat with methylene blue and supplemental O2
Gel type in electrophoresis that can distinguish between HbA2 vs HbC; HbS vs HbD; HbF vs HbA
Citric agar
FDA approved pill for hemolytic anemia from pyruvate kinase def?
Mitapivat (pyrukynd)
Phosphoglycerate kinase deficiency inheritance and gene affected?
X-linked recessive; PGK1 gene
Spleen regresses after blood transfusion?
splenic sequestration crisis
Voxelotor?
increases affinity of hb for oxygen, preventing polymerization and sickling of RBCs in SCD
Crizanlizumab
Ab against P-selectin to prevent sickle cell crisis frequency
SC disease specific presentation?
proliferative retinopathy; milder crisis
Betibeglogene autotemcel (beti-cel)?
gene therapy for transfusion dependent b-thal transduced by lentiviral vector via HCST, 89% pts achieve transfusion independence
Abnormal folding of which protein leads to Southeast Asia ovalocytosis (RBC appear as stomatocytic elliptocytosis)?
Band 3
MC coombs pattern for warm AIHA? cold agglutinin disease?
warm IgG+, C3+
cold ag disease IgG-, C3+
RBC antigen inplicated in cold agglutinin disease?
i Ag
Tx for cold agglutinin disease with severe life-threatening hemolysis?
plasmapheresis or IVIG (both have transient effect)