Case 30: 2yo - Sickle cell disease, hemolytic anemia Flashcards
4yo child previously healthy (no meds), recently came back 2w ago from Pakistan –> fevers (up to 102F), chills for 3d, very tired over last 24h.
Hgb 8.5
WBC 8.2
Plt 410
- Had been dehyrated, given fluid bolus
- Given Tylenol for the fevers
- Mildly jaundiced (scleral icterus)
- brown urine every time he has a fever (tea colored): chills - fever - brown urine ==> then clears until next fever.
Negative Fhx
Vitals unremarkable
Physical exam - no rash, hepatosplenomegaly, abd masses, no fixed nodes
what tests do you want next?
- CBC = Hgb, WBC, Plt, MCV
- Reticulocyte count («1% production problem v. »_space;1% destruction problem = hemolysis) ==> can falsely elevate MCV
- ferritin (can be elevated with illness)
- haptoglobin
- peripheral blood smear
- UA
- Direct Coombs (DAT) = to determine if autoimmune or not
- Hgb electrophoresis (if DAT negative)
==> ultimately DAT+ for C3 (no IgG)
+send out for Donath landsteiner test
paroxysmal cold hemoglobinuria
MCV lower limit of normal
70+age
Anemia in a kid with URI. is this normal?
not “normal” – but likely due to viral cause of destruction of >/=1 cell line
4yo with fever, anemia, and rash
Diffdx: parvo – b/c everyone destroys RBCs with this
in a kid with iron deficiency anemia, what is the first sign?
1) increased RDW >16%
2) decrease in Hgb, MCV
autoimmune hemolytic anemia labs
- CBC = low Hgb, nml WBC, high Plt, nml MCV
- Reticulocyte count»_space;1% destruction problem = hemolysis
-ferritin (can be elevated with illness)
- haptoglobin <31 (low d/t loss increasing binding of iron ==> hemolysis)
-peripheral blood smear = spherocytes, helmet cells / schistocytes
-UA = 1.03 / pH 65 / 2+ heme / no protein, no RBCs, no WBCs
==> intravascular hemolysis (b/c + heme, - RBCs) rather than renal issue
-Direct Coombs (DAT): 3+ == positive; IgG or C3
diffdx:
non-autoimmune hemolytic anemia
1) hemoglobinopathy (congenital hemolytic anemia)
2) membranopathy == hereditary spherocytosis, hereditary ellipticocytosis
3) RBC enzyme deficiency == G6PD deficiency, pyruvate kinase deficiency
4) paroxysmal nocturnal hemolytic anemia = membrane deficiency in CD55/CD59, with hyper-attachment of C5 (complement)
TTP
Adam13 mutation == cleaves high
congenital == does not make enzyme Adam13
autoimmune == make antibody against Adam13
diffdx for spontaneous thromboses
paroxysmal nocturnal hemolytic anemia
Factor 5 lyden
diffdx:
autoimmune hemolytic anemia (positive Coombs)
IgG +/- C3 == warm auto-Ab
C3 +, IgG -
1) cold agglutinin (IgM+, cold agglutinin titer HIGH) == hemolyze at cold temperatures. Attaches to antigen “I”
2) paroxysmal cold hemoglobinuria (IgG+ in cold environment [periphery body], then hemolyze in warm environment [central body]. Attaches to antigen “P” ==> Fever (with cold extremities = IgG+ in extremities) –> the spread throughout ==> HEMOLYZE
how to treat warm v. cold agglutinin hemolytic anemia
warm agglutinin
1) cross-match ==> find the least incompatible unit of blood
2) Steroids
cold agglutinin - either cold / paroxysmal cold ==> want to keep warm so that they don’t hemolyze
1) KEEP WARM - no cold fluids, foods
2) TRANFUSE with WARM BLOOD
+/- steroids in PCH
conditions associated with cold agglutinins
EBV
Mycoplasma
Hep C
how to diagnose paroxysmal cold hemoglobinuria
Donath Landsteinertest = serum (with IgG) + non-patient RBCs at 4 C –> 37C
what hereditary blood disorders protect against Malaria
G6PD deficiency
sickle cell disease/trait
thalassemia
define: malaria belt
mediterranean == beta thalassemia
Middle East == beta thalassemia
Africa
south east asia == alpha thalassemia
what can precipitate paroxysmal cold hemoglobinuria?
Viral illness ==> causing fever ==> causing MASSIVE hemolysis over his baseline level of hemolysis ==> tea- or brown-colored urine
complications of hemolytic anemia
+/- giving more blood in autoimmune hemolytic anemia
Fulminant real failure
prevention
- fluid boluses
- 2* MIVF
reticulocyte production index (RPI)
reticulocyte production index (RPI)
RPI = retic% * (pt Hct / nml Hct)
RPI = retic% * (pt Hct / 45)
sickle cell disease (SCD)
- pathophysiology:
- signs and symptoms
- labs / findings
- pathophysiology [AUTOSOMAL RECESSIVE] substitution of valine FOR glutamic acid in Hgb molecule ==> formation of Hgb polymers that becomes deoxycgenated ==> “sickling” of RBCs
==> increased adherence, block blood flow in microvasculature ==> local tissue hypoxia, pain, tissue damage
==> induced hemolysis of RBCs ==> chronic anemia ==> increased reticulocyte count - signs and sxs
- anemia
- jaundice = increased breakdown of RBCs
- pain and swelling in extremities
- fatigue, need to sleep more
1) splenic enlargement (@2-3yo), then splenic fibrosis (@4-5yo)
2) jaundice == d/t RBC hemolysis
3) signs of stroke - CBC: leukocytosis, thrombocytosis @ stress
describe the Hgb type ad what the pattern means:
F
predominant hgb at birth
describe the Hgb type ad what the pattern means:
A
normal adult hemoglobin
describe the Hgb type ad what the pattern means:
FAS
Baby carries one normal, one abnormal (S) allele
==> benign sickle cell trait
describe the Hgb type ad what the pattern means:
FAC
Baby carries one normal, one abnormal (S) allele
==> benign Hgb C trait
describe the Hgb type ad what the pattern means:
FS
BOTH alleles have mutation for Hgb S
==> sickle cell disease
- splenomegaly in childhood; splenic fibrosis in teens
describe the Hgb type ad what the pattern means:
FSA
sickle cell beta thalassemia
1 globin gene has mutation for S
other globin gene has mutation for B-thalassemia == no Hgb or dysfunctional Hgb
==> sickling disorder, milder v. sickle cell disease
(treated similarly to sickle cell disease - FS)
- can have splenomegaly into teens