Hemat Flashcards
? ml blood has 1 mg iron
2ml blood = 1mg iron
Daily requirement = 1-2mg
Iron chelation drugs
- Deferoxamine (IV/SC)
- Deferiprone
- Deferasirox
Deferoxamine (aka Desferrioxamine)
- Deferoxamine
- IV/SC
- Prefer: Slow SC infusion over 8-12h
- SE: Local skin reactions, infection (Yersinia, Klebsiella), Growth retardation, skeletal abnormalities in children, hearing, visual problems
Deferiprone
- Deferiprone
- Oral
- 75mg/kg/day given tds
- Better cardiac function than Desferoxamine
- SE: Agranulocytosis (0.2/100 in 1y; CBC weekly at least in first 3 months), Arthropathy
- 1st line in thal major (but not in other transfusion dependent patient)
- Switch to Deferasirox if agranulocytosis
Deferasirox
- Deferasirox
- Oral, long half-life
- Once daily 20-30mg/kg
- SE: GI disturbance, reversible rise in creatinine
- CI in renal failure
Mx of thal major
- Confirm Dx with Hb pattern and thalassemia genotype; Screen family members
- Extend RBC Ag typing before transfusion to safeguard development of alloautoAb in future
- Check HBV, HCV, HIV before transfusion
- Give Rh C, c, E, e, Kell Ag compatible blood to minimize alloimmunization
- Aim pre-transfusional Hb at 9, Usual transufsion interval 3-4 wk
- Give WBC reduced, fresh packed cells
- Perform full pre-transfusion compatibility test and Ab screening before each transfusion
- Splenectomy only if Sx of splenomegaly or transfusion requirement >200ml/kg/yr as result of hypersplenism
Monitor iron overload
- Serum ferritin
- Monitor ferritin every 3m
- Iron chelation to keep ferritin <2500mg/L (preferably 1000)
- Persistent >2500 –> increased cardiac risk, mortality
- Ferritin monitoring often underestimates degree of iron overload in Thal intermediate
Tumor lysis syndrome
Hyper
-uric acid, K, phosphate, LDH
Hypo
-Ca
Tx
- Aggressive hydration (beware of fluid overload)
- Alkalinzation of urine (may worsen RFT due to Ca phosphate deposition)
- Allopurinol, Febuxostat (Xanthine oxidase inhibitor)
- Rasburicase (Recombinant urate oxidase in Aspergillus flavus, avoid in G6PD deficiency)
- Renal replacement therapy
- Monitor WBC, tumor size, fluid intake, urine output, body weight, electrolytes, RFT, LDH, pH, PT/APTT
LDH
A Lie
Lactate dehydrogenase
- Located in inner surface of cell membrane
- Converts lactate to pyruvate
- Anaerobic reaction
Bite cells
G6PD
aka Degmacyte
>=1 semicircular portions removed from the cell margin
Bites: due to removal of denatured Hb by MQ in the spleen
G6PD: uncontrolled oxidative stress causes Hb to denature and form Heinz bodies
Schistocyte
Fragmented part of RBC
In DIC, TTP, artificial heart halves
Hypersplenism 4 cardinal features
- Pancytopenia
- Hyperplastic BM
- Corrected by splenectomy
- Splenomegaly
Lab features of Hemolytic anemia
- Anemia - usu mild macrocytic, with reticulocytosis
- ↑Unconjugated bilirubin, LDH, methemalbumin
- ↓Serum haptoglobin
- Blood film
- Polychromasia
- Spherocytes (hereditary spherocytosis, immune hemolytic anemia)
- RBC fragmentation (microangiopathic hemolysis)
- RBC agglutination (cold agglutinin disease) - Direct antiglobulin test (Direct Coomb’s test) – positive in immune hemolytic anemia
AI hemolytic anemia
Warm (IgG), Cold (IgM)
- Both can be due to secondary cause
- Warm: Drug (e.g. Methyldopa), SLE, CLL
- Cold: infection e.g. Mycoplasma, IM, lymphoproliferative disorders
Tx of AIHA
- Transfusion if needed
- Folate supplement
- Decrease further hemolysis: steroid, avoid certain drugs, keep warm for cold hemagglutinin disease, splenectomy
- Treat underlying causes e.g. lymphoproliferative disorders
Dx of AIHA
- ↑Reticulocytes
- Blood film showing microspherocytes
- ↑Unconjugated bilirubin, LDH, methemalbumin
- ↓Haptoglobin
- Specific tests: Direct antiglobulin test (aka Direct Coombs’ test)
Aplastic anemia, clinical features
- Pancytopenia resulting from BM hypoplasia or aplasia
- Can be Congenital/Acquired (Acquired: Idiopathic/Secondary)
- Can be pure red cell aplasia, e.g. Diamond-Blackfan syndrome, or asso w/ large granular lymphocytosis
Clinical features
- Symptoms of pancytopenia
- No lymphadenopathy
- No hepatosplenomegaly
- Look for congenital physical abnormalities in young patients (inherited BM failure syndromes)
Etiology of Aplastic anemia
Idiopathic (70-80%)
- Pathogenesis (for idiopathic)
- Immune mediated T cell destruction of BM stem cells (IL-17 CD4, TH-17)
- Over-expression of HLA-DR2
- Polymorphism in perforin gene / TNF-alpha gene
- ∴Tx is by immunosuppressant
Congenital: Fanconi anemia, Shwachman-Diamond syndrome, Dyskeratosis congenita
Drugs: Gold, alcohol, diclofenac acid, indomethacin, chloramphenicol, anti-convulsants
Infection: Non-A/B/C hepatitis (Seronegative hepatitis)
Environmental: Benzene, pesticide
Tx of Aplastic anemia
- Supportive
- Cyclosporin A
- Anti-thymocyte globulin + Cyclosporin
- 1st line = Allogeneic HSCT (for young patients with matched sibling donors)
- Eltrombopag (high dose) – for relapse/refractory cases
Ix of Aplastic anemia
- CBC: Pancytopenia, macrocytic anemia (not as big as blasts), low reticulocyte
2, Blood film - AI markers
- Vit B12 and folate levels
- BM: Trephine biopsy to assess cellularity
- Specialized tests
- Ham tests/flow cytometry to rule out PNH (Paroxysmal Nocturnal Hemoglobinuria)
- Chromosome breakage with diepoxybutane (to screen for Fanconi anemia)