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Hemolytic anemia, Hereditary spherocytosis and G6PD deficiency
1. HEMOLYTIC ANEMIA–
Hereditary spherocytosis and
G6PD deficiency
Dr. Kalpana Malla
MD Pediatrics
Manipal Teaching Hospital
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12. ETIOLOGY
• Usually AD . Rarely AR
• 25% have no F/H. New mutations
• Northern Europe most common
• Also seen in SE Asia incl. India, Nepal
13. RBC CYTOSKELETON
• “Vertical” and “horizontal” interactions b/w
proteins and lipids
• Lipid bilayer skeleton
• Spectrin and Ankyrin : major components
• Spectrin has α and β chains
• Protein 3 also present
• Deficiency in either of the 3 causes problem in
the “vertical” interactions
14. MOLECULAR PATHOPHYSIOLOGY
Deficiency in spectrin, ankyrin, protein 3
Lipid bilayer skeleton uncoupling
Membrane loss in the form of microvesicles
Surface area deficiency
Spherocytosis
Impaired passage through splenic cord
Sequestration
15.
16. VARIOUS PRESENTATIONS
• Hemolytic d/s of newborn
• Hemolytic crisis : most common form
• Aplastic crisis
• Megaloblastic crisis
• HS in pregnancy
18. HS IN NEONATES
• Hemolytic d/s of newborn
• Prolonged neonatal jaundice
• May require PT/ exchange transf.
• Anemia progressing to CCF
• Hydrops fetalis (rare)
• Palpable spleen
• Investigate parents
19. HEMOLYTIC CRISIS
• Pptd by viral inf : Infectious
mononucleosis
• Exercise induced
• Anemia,jaundice
• Vomiting, abd pain, tender spleen
• May happen also during recovery phase
of aplastic crisis
20. APLASTIC CRISIS
• Less common, more serious
• Parvovirus B19
• Fever, chills
• Vomiting, diarrhea, myalgias
• Slapped cheek apearance
• Foll this - sudden pallor, jaundice,
weakness
21. PATHOGENESIS OF APLASTIC CRISIS
• Parvovirus affects erythropoetic precursors -> arrests
cell cycle in G2 phase -> apoptosis.
• Also transient neutropenia, thrombocytopenia
(pancytopenia)
• BM: giant pronormoblasts (hallmark)
• Unused iron levels increase in serum
• Hematocrit and retic count falls
• Self limiting process. Self recovery after sometime
22. MEGALOBLASTIC CRISIS
• Due to a secondary folate deficiency
• In patients recovering from aplastic crisis
• Hence supplement 1mg/day of F.A. to
children with HS
23. COMPLICATIONS
• Gall stones : young adults/ adolescence .
• Gout, Leg ulcers
• Chronic erythematous dermatitis of legs
• Extramedullary hematopoesis
• Hematologic malignancies : multiple
myeloma, leukemia, hepatoma
• Heart disease: CCF, cardiomyopathy
25. INVESTIGATIONS
• BM: erythroid hyperplasia
• Decreased haptoglobin
• Incubated Osmotic fragility test (deprive
RBC off glucose overnight): increased
fragility to hypotonic saline
• Autohemolysis: spont cell breakdown
after incubation for 48 hrs at 37C.
Normally <4%, In HS >10-15%
• Molecular and genetic analysis
26.
27. OSMOTIC FRAGILITY
100
80
% Hemolysis
60
40
20
0
0.3 0.4 0.5 0.6
NaCl (% of normal saline)
Normal HS
28. Other conditions associated with
spherocytes on PS:
• Auto-immune hemolytic anemia
• Burns
• Wilson’s disease
• Chemical injury
• Infections
• HDN due to anti-A
29. Treatment:
• If Hb > 10 gm/dl and retics < 10%- no Rx
• If severe anemia, poor growth, aplastic
crises and age < 2 yrs- transfusion
• If Hb < 10 gm/dl and retics > 10 % or
massive spleen- splenectomy
• Folic acid- 1 mg/day
30. TREATMENT
• Splenectomy
• Folic acid 1 mg/day
• Blood transfusion SOS
• Cholecystectomy for gall stones
34. • Two clinical syndromes:
- Episodic / induced hemolytic A
- Spontaneous chronic non-
spherocytic hemolytic A
• Inheritance of abnormal alleles of
gene responsible for synthesis of
G6PD molecules
35. ETIOLOGY
• X-Linked recessive
• Evolutionary advantage of resistance
to falciparum malaria
• 90 mutations of G6PD gene
• Normal enzyme : G6PD B+
• Variant: G6PD A+ (African-American)
G6PD A -
36. • Synthesis of G6PD determined by
X chromosome
• Usually only males affected
• Heterozygous females
(intermediate enzyme activity)
usually not symptomatic…unless
random inactivation of normal X
chromosome (rarely) Lyon’s
hypothesis
37. FUNCTION OF G6PD
• Regenerates NADPH, allowing regeneration
of glutathione
• Protects against oxidative stress
• Lack of G6PD leads to hemolysis during
oxidative stress- infection, medication, fava
beans
• Oxidative stress leads to Heinz body
formation, extravascular hemolysis
41. TYPES
• Type 1: mild (G6PD A-): Afro- americans
• Type 2: moderately severe (G6PD B- and
G6PD Canton): SE Asia, Mediterranean
• Type 3: chronic: North America and
Europe
OR
• Episodic hemolytic anemia
• Spontaneous chronic nonspherocytic
hemolytic anemia
42. CLINICAL FEATURES
Exposure to drug
24-48 hr
• Severe progressive anemia, cardiac failure
and jaundice
• Favism: hemolysis after ingestion of fava
beans
43. TYPE 1
• Mildest form (enzymes 8-15 % of normal)
• Episodic form
• Sensitive to strong oxidants
• Usual doses of aspirin and Co-trimox well
tolerated
• Young RBC have high conc of enzyme ->
hence no neonatal jaundice
• Hemolysis doesn’t continue after intial
hemolysis as ageing G6PD cells dead and
young ones have enzyme
44. TYPE 2
• Moderately severe
• Episodic form
• Fava exposure + oxidants
• Neonatal Jaundice present
• Hemolysis continuous with continuous
administration of drug
• Assoc with viral hepatitis – severe
jaundice
• Encephalopathy sometimes
45. TYPE 3
• Chronic type
• Spontaneous, without any ppt factor
• If ppt factor given -> severe hemolysis with
hemoglobinuria
• Severe neonatal jaundice -> kernicterus
• Hemolysis after febrile episode
• Enzyme level very very low
49. WHY?
• During acute hemolysis- all deficient cells
have been hemolysed
• Young cells will be in circulation
• Young surviving cells may have normal levels
of the enzyme
• Hence falsely normal during acute episode
• Assess 2-4 months later
• Deficient G6PD levels will be evident
• Usually affected have <10% of normal level
50. TREATMENT
• Avoid the oxidants
• Blood transfusion
• Sodium bicarbonate to alkalinise urine in
severe Hburia… or else acid hematin ppt in
renal tubules
51. Thank you
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Medical Post [ www.themedicalpost.net ]