Hereditary spherocytosis: Difference between revisions
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== | ==Background== | ||
*Hereditary | *Hereditary hemolytic anemia due to defect in RBC cell membrane (mainly spectrin, ankyrin) | ||
**75% Autosomal Dominant, 25% Autosomal Recessive | **75% Autosomal Dominant, 25% Autosomal Recessive | ||
===Pathophysiology=== | |||
==Pathophysiology== | |||
*Deficient/Nonfunctional RBC cell membrane proteins that connect the cell membrane skeleton to the lipid bilayer | *Deficient/Nonfunctional RBC cell membrane proteins that connect the cell membrane skeleton to the lipid bilayer | ||
==Clinical Features== | |||
*Classic triad: [[anemia]], [[jaundice]], splenomegaly | |||
== | ===Mild=== | ||
* | *No anemia, normal retic count, little or no jaundice/splenomegaly | ||
*No RBC transfusions | |||
*Dx’d later in life | |||
===Moderate=== | |||
*Anemic, elevated retic, elevated bili, maybe splenomegaly | |||
*May require RBC transfusions | |||
*Dx’d in infancy or early childhood | |||
===Severe=== | |||
*Marked [[hemolytic anemia|hemolysis]], [[anemia]], [[hyperbilirubinemia]], splenomegaly | |||
*Require regular RBC transfusions | |||
*Dx’d in infancy | |||
==Differential Diagnosis== | |||
{{Hemolytic anemia DDX}} | |||
== | ==Evaluation== | ||
*Low | *Low hemoglobin, elevated retic count, spherocytes on peripheral smear | ||
*Elevated MCHC (RBC membrane leaky causing RBC dehydration) | *Elevated MCHC (RBC membrane leaky causing RBC dehydration) | ||
*Osmotic fragility test, AGLT, EMA binding test, cryohemolysis | *Osmotic fragility test, AGLT, EMA binding test, cryohemolysis | ||
**One study showed AGLT + EMA binding test identified all HS | **One study showed AGLT + EMA binding test identified all HS patients | ||
*Negative Coombs test | *Negative Coombs test | ||
==Management== | |||
*[[Folic acid]] | |||
*[[pRBC]] transfusion | |||
== | |||
*Folic acid | |||
* | |||
*EPO | *EPO | ||
*Splenectomy | *[[Splenectomy]] | ||
**As late as possible, preferably >6 yo | **As late as possible, preferably >6 yo | ||
**Post-op need encapsulated bacteria | **Post-op need encapsulated bacteria prophylaxis: Strep Pneumo, H Influenza, Neiserria Meningitidis | ||
**Possible higher risk of arterial/venous thrombosis in HS after splenectomy | **Possible higher risk of arterial/venous thrombosis in HS after splenectomy | ||
*Hematopoietic cell transplant (most agree risks outweigh benefits) | *Hematopoietic cell transplant (most agree risks outweigh benefits) | ||
==Complications== | |||
*[[Cholelithiasis]] secondary to intravascular hemolysis causing development of bilirubin gallstones | |||
*Pseudohyperkalemia: K+ leaks out of RBCs after blood draw | |||
==See Also== | ==See Also== | ||
[[Category:Heme/Onc]] | [[Category:Heme/Onc]] | ||
Latest revision as of 14:58, 1 September 2019
Background
- Hereditary hemolytic anemia due to defect in RBC cell membrane (mainly spectrin, ankyrin)
- 75% Autosomal Dominant, 25% Autosomal Recessive
Pathophysiology
- Deficient/Nonfunctional RBC cell membrane proteins that connect the cell membrane skeleton to the lipid bilayer
Clinical Features
Mild
- No anemia, normal retic count, little or no jaundice/splenomegaly
- No RBC transfusions
- Dx’d later in life
Moderate
- Anemic, elevated retic, elevated bili, maybe splenomegaly
- May require RBC transfusions
- Dx’d in infancy or early childhood
Severe
- Marked hemolysis, anemia, hyperbilirubinemia, splenomegaly
- Require regular RBC transfusions
- Dx’d in infancy
Differential Diagnosis
Microangiopathic Hemolytic Anemia (MAHA)
- Disseminated Intravascular Coagulation (DIC)
- Thrombotic Thrombocytopenic Purpura (TTP)
- Hemolytic Uremic Syndrome (HUS)
- HELLP syndrome
- Heparin-Induced Thrombocytopenia (HIT)
- Hereditary spherocytosis
- Paroxysmal nocturnal hemoglobinuria (PNH)
- Malignant hypertension
- Scleroderma
- Antiphospholipid Syndrome (APS)
- Other medical causes: malignancy, renal allograft rejection, vasculitides like polyarteritis nodosa and Wegener's granulomatosis
- Drugs: chemotherapy; Clopidogrel (Plavix) associated with TTP
- Nonvascular causes: prosthetic valve (more common with mechanical, more common at aortic valve), LVAD, TIPS, coil embolization, patched AV shunt, AVM
Evaluation
- Low hemoglobin, elevated retic count, spherocytes on peripheral smear
- Elevated MCHC (RBC membrane leaky causing RBC dehydration)
- Osmotic fragility test, AGLT, EMA binding test, cryohemolysis
- One study showed AGLT + EMA binding test identified all HS patients
- Negative Coombs test
Management
- Folic acid
- pRBC transfusion
- EPO
- Splenectomy
- As late as possible, preferably >6 yo
- Post-op need encapsulated bacteria prophylaxis: Strep Pneumo, H Influenza, Neiserria Meningitidis
- Possible higher risk of arterial/venous thrombosis in HS after splenectomy
- Hematopoietic cell transplant (most agree risks outweigh benefits)
Complications
- Cholelithiasis secondary to intravascular hemolysis causing development of bilirubin gallstones
- Pseudohyperkalemia: K+ leaks out of RBCs after blood draw