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)
Tx of primary cold agglutinin disease with anemia and/or symptoms?
BR (bendamustine rituximab)
Tx Cold Agglutinin Disease with anemia requiring transfusion and/or severe symptoms?
Sutimlimab (monoclonal Ab against C1)
coombs pattern for paroxysmal cold hemoglobinuria (PCH)? Tx of acute episode?
IgG-, C3+
supportive, avoid cold. can offer steroids if dont respond in 1-2 weeks. rarely offer cyclophosphamide, rituxan, and azathioprine if persistent hemolysis
Mutations in hereditary spherocytosis?
SPT (spectrin), ANK (ankyrin), and SLC (band 3)
Definitive test for diagnosis of hereditary spherocytosis? Tx?
Eosin-5-maleimide (EMA); folic acid, pRBC and splenectomy
Inheritance pattern for Hereditary Eliptocytosis
AD
McLeod neuroacanthocytosis syndrome?
lack of kell Antigen. X-linked
auto rec disorder that interferes with absorption of fat-soluble vitamins (A, D, E, K)?
abetalipoproteinemia (acanthocytes)
neonatal jaundice; chronic non-immune, non-spherocytic, hemolytic anemia; iron overload
pyruvate kinase def
lead poinsoning leads to deficiency in?
pyrimidine-5-nucleotidase
metformin can lead to decrease absorption of Vit _?
B12 -> megaloblastic changes in BM, pancytopenia
GCSF can lead to ARDS via what mechanism?
sequestration of granulocytes in the pulmonary circulation
Tx for acquired methemoglobinemia with G6PD def?
ascorbic acid (Vit C)
MC cause of pure red cell aplasia in children?
TEC (transient erythroblastopenia of childhood) – healthy child suddenly develops anemia with low retics
Oral iron with fewer GI side effects?
Ferric maltol (non-salt formulation)
RBC with fish-mouth central pallor?
stomatocyte
Does cyanosis occur in carboxyhemoglobin or hemoglobin variant with high oxygen affinity?
NO
Osler-Weber Rendu syndrome (aka hereditary hemorrhagic telangiectasia HHT) has 4 main characteristics?
- recurrent nosebleeds
- multiple mucocutaneous telangiectasia
- visceral involvement
- first degree relative with HHT
Define mild, moderate and severe hemophilia A?
Mild: 5-50%
Mod: 1-5%, bleed after injury/surgery
Severe: <1% Factor VIII, spontaneous bleeding
Factor dosing in hemophilia A/B?
Factor 8: 1U/kg raises by 2%
Factor 9: 1U/kg raises by 1%
Goal during severe-life threatening bleed is 100% (Give 50U/kg of F8 or 100U/kg of F9).
Goal during joint bleed is 50% (Give 25U of F8 or 50U of F9)
Maintenance goal. Keep factor level >50%
Hemophilia A factor goal prior to surgery?
Goal for surgery is 80-100%, do not let drop below 50%.
Hemophilia A factor goal prior to surgery?
Goal for surgery is 60-80%
Ppx F8 dosing for hemophilia A?
20-30 U/kg three times per WEEK
goal > 1%
Benefits of emicizumab for Hemophilia A? MOA?
-SubQ
-weekly dosing
-no structural relationship to F8 therefore no inhibitor development
MOA: IgG4 Ab to F9a and F10, bridging these two factors and restoring the function of the mission activated FVIII.
*Cannot use in active bleeding
Tx for severe bleeding when high-titer factor VIII inhibitor (>5 bethesda units) is present?
activated PCC (prothrombin complex concentrate aka FEIBA) or recombinant human factor 7a, or recombinant porcine factor 8.
Most common coagulation factor deficiency in amyloid light-chain amyloidosis?
acquired factor X deficiency
Goal of VWF and F8 level at time of delivery and 3-5 days postpartum?
> 50
how do you differentiate between primary fibrinolysis and DIC?
DIC has elevated D-dimer
Tx for hereditary factor X deficiency?
Coagadex (factor X plasma derived concentrate)
Triad of aortic stenosis, intestinal angiodysplasia, and TYPE IIA vWD? Tx?
Heyde’s Syndrome. Valve replacement will resolve the anemia and vWD
What does FEIBA (factor eight inhibitor bypassing activity) contain?
prothrombin, factor 7, 9, 10
What does Kcentra (prothrombin complex concentrate PCC) contain?
Factor 2, 7, 9, 10 and protein C and S
Indication for rebinyn?
on-demand treatment and control of bleeding episodes, perioperative management of bleeding, and routine prophylaxis with hemophilia B
Ideal prophylactic treatment for hemophilia A that has least chance of developing inhibitor?
emicizumab > plasma-derived factor VIII containing vWF > everything else
Humate P dose prior to tooth extraction?
20-40U single infusion, goal>50%
Substance in synthetic cannabinoids that causes severe bleeding? MOA?
brodifacoum, potent vit K antagonist. give high doses of vit K for months considering half-life is 20 days
Humate P dose prior to surgery
40-60U load followed by :
minor surgery: 20-40U every 12-48hours x1-5 d
major surgery: 20-40U every 8-24 hours x7-14 days
Goal > 50%
preferred treatment for type 1C, 2, and 3 VWD?
Humate-P (intermediate-purity factor VIII prep that contains vWF)
Humate P dose for spont or traumatic bleed?
25U daily for 2-4d for goal>50%
best rapid treatment for uremic platelet bleed?A
DDAVP