heme/onc Flashcards

(60 cards)

1
Q

What are the sites of erythropoiesis

A

embryo –> yolk sac fetus during first trimester through birth –> liver fetus during second trimester through adulthood –> bone marrow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Describe chronology of hemoglobin switching

A

Embryonic Hb during 1st trimester from yolk sac: includes HbGower 1 [z2e2], [a2e2], and Hb Portland [z2g2].

Fetal Hb (HbF) is a2g2, predominant Hb during fetal life and newborn (75% at birth). Doesn’t bind to 2,3 dbg which makes it have higher affinity for O2.

Adult Hb (HbA) is a2b2 and minor form HbA2 a2d2 increase after birth. Majority is HbA by 6m.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

How are fetal RBCs different than adult RBCs

A
  • larger MCV
  • shorter life span 60-80d instead of 120
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

describe erythropoises in neonate

A

Epo production starts in liver initially and switches to kidney near birth. Erythropoeisis under control of neonate b/c epo doesn’t cross placenta. Higher production than adults because of relative hypoxia.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

When does physiologic anemia of infancy happen and how is it different from anemia of prematurity

A

Anemia of infancy happens at about 8-12w in term infants, at an average of Hb 11.

Anemia of prematurity is multifactorial and usually at 6w with Hb 7-10.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Describe hemolytic disease of the newborn

A

HDN is usually due to maternal IgG against D Ag on RBC crossing placenta. This is clinically significant usually only after 2nd pregnancy. It can also be against C, E, anti-Kell and anti-Duffy antigents.

Anti-Kell also impacts reticulocytes.

In contrast, it is not usually severe with ABO incompatibility, although ABO hemolytic anemia can happen during first pregnancy and is not more severe with subsequent pregnancies.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

how does RhoGAM work

A

RhoGAM is anti-D Ab. It is given to Rh- moms at 28w and 7w after delivery. It clears Rh+ fetal cells from maternal circulation before mother can make her own anti-D Ab.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Describe the different a thalassemias

A

There are four copies of a-globin gene on chr. 16.

more commonly in aa:

Deletion of 1 gene: silent carrier.

Deletion of 2 genes: a-thal trait. Mild anemia.

more commonly in asian:

Deletion of 3 genes: majority Hb B, and later in infancy HbH (b4)

Deletion of 4 genes: homozygous a-thal. mostly Hb Barts (g4)

HbH and HbBarts usually results in severe fetal anemia and hydrops.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Describe the types of B-Thallesemia

A

We have two copies of B-globin gene on Chr. 11. Gamma-globin in fetus prevents B-thal babies from being symptomatic as a fetus, usually mild symptoms at most in neonate.

Deletion of B-globin gene can results in silent carrier, B-thal trait, B- thal intermedia and B-thal major.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the genetic mutation that causes HbS

A

point mutation at position 6 in B chain replacing valine with glutamic acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is appropriate follow up for NBS for hemoglobinopathies?

A

Initial NBS is done using isoelectric focusing and high-performance liquid chromatography.

Anormal tests should be confirmed with Hb electrophoresis at 6 months.

HbS infants can benefit from PCN ppx, immunization against h. flu and s. pneumoniae.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are two major intrinsic RBC defects that cause non-immune mediated hemolysis?

A

1) Glucose 6 Phosphate Dehydrogenase (G6PD) Deficiency: G6PD supplies NADPH to reduce glutathione in RBC via hexose monophospate shunt/pentose phosphate pathway. Without this, during oxidative stress hemolysis occurs. X-linked recessive. More common in AA and Medidterranean descent. Difficult to diagnose during crisis because immature RBCs have higher levels of G6PD.
2) Pyruvate Kinase (PK) deficiency: PK is enzyme in glycolysis, if deficient RBC cannot produce enough energy –> hemolysis. Autosomal recessive.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are membrane protein defects causing non-immune hemolysis?

A

1) Spherocytosis: AD defect in ankyrin. Dx: Spherocytes on smear, osmotic fragility test.
2) Elliptocytosis: AD mutation in a/b spectrin. Dx: ovalocytes. Milder anemia than spherocytosis.
3) Pyropoikilcytosis: mutations of a or b spectrin.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is Diamond - Blackfan Anemia

A

DBA is an AD bone marrow syndrome causing impaired erythropoises –> paucity of erythrocyte precursors, non-megaloblastic (vs b12/folate def) macrocytic anemia, reticulocytopenia, and assc with short stature, abnormal facies, abnormal (triphalangeal) thumbs and skeletal abnormalities. Mutations in genes that code ribosomal units.

pneumonics: diamond ring (finger — tri phalyngeal thumb), ‘black’fan - bone marrow is dark without any rbcs, ‘non-mega’loblastic –> congenital

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is Fanconis Anemia

A

Bone marrow syndrome, anemia +/- thrombocytopenia/leukopenia. Usually presents in late childhood. Due to BRCA2 mutation –> defect in DNA repair enzymes. Higher incidence of cancer. Inherited aplastic anemia, AR. Hypoplastic or absent thumb, radius bone abnormalities.

pneumonic: ‘fan’ –> brrr –> BRCA mutation / fan cuts off your thumb

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is Shwachman-Bodian-Diamond Syndrome?

A

Bone marrow failure syndrome. Neutropenia +/- anemia/thrombocytopenia. Assc with exocrine pancreatic insufficiency and skeletal abnormalities. Due to SBDS gene mutation on chr. 7.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is Pearson Syndrome?

A

Mitochondrial disease with anemia, exocrine pancreatic insufficicency, renal and hepatic failure.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is appropriate iron supplemenation to avoid iron deficiency anemia.

A

Term infants : On formula, no additional Fe needed. If >50% breast milk, 1mg/kg Fe starting at 4 months.

Preterm infants: 2mg/kg Fe starting at 1m.

Wait to give cow’s milk until 1 y/o –> not enough Fe.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what are symptoms of chronic kernicterus

A

dental dysplasia, hearing loss, choreoatheosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what are sypmtoms of acute bilirubin encephalopathy

A

hypertonia (opisthotonis/retrocollis), high pitched cry, fever, poor feeding. Preterm infants will have abornmal BAER.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

In hematopoiseis, what do lymphoid progenitors and myeloid progenitors become?

A

lymphoid: all lymphocytes including B cells, T cells and NK cells
myeloid: RBCs, platelets, and other WBCs including granulocytes, monocytes and macrophages

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

In NAIT, what is the most common platelet antigen involved

A

HPA-a1 (75%)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

how low do platelets get in NAIT and what is the typical course and treatment?

A

Can have severe thrombocytopenia (<50k), usually recovers after 3d b/c Ab wear off. 10% can have intercranial bleed.

Treat with anti-antigen platelets, or maternal washed platelets. Normal pooled platelets are fine too. Steroids and IVIG are optional.

There is a high recurrence rate in moms, treating prenatally with IVIG and steroids can help.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What are characteristic features of TAR?

A

Thrombocytopenia that resolves in a year, due to maturation defect in megakaryocyte progenitors. Unlike fanconis, thumbs are normal. Radii are absent. High risk of ICH.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Which factors are affected in Hemophilia? What marker will be elevated? What are the patients at risk for?
F VIII (A) and F IX (B/christmas). Both are X linked recessive. Prolonged PTT. Factor levels will be decreased, that is definitive diagnostic test. 1/3 can have clinically significant bleeding in neonatal period including ICH.
26
What is the most common inherited bleeding disorder?
VW disease is rarely diagnosed in neonatal period b/c VW levels are elevated in neonate. Treat with VW containing F VIII concentrate. DDAVP contraindicated in neonates due to risk of hyponatremia.
27
How does Vit K deficiency present and how is it diagnosed?
Can be early (24h), classic (upto 1w) or late (most commonly presents as ICH. PT is prolonged. Vit K needed to make F II, VII, IX, and X. Patients who are exclusively breastfed and who do not get Vit K IM are at risk.
28
How and why does neonatal purpura fulminans present?
It is due to deficiency of protein C and protein S (anticoagulation factors that are vitamin K dependent and produced by the liver). Assc with GBS bacteremia. Presents as purpura. Treat with FFP.
29
Wilms Tumor/nephroblastoma: benign/malignant clinical features diagnosis treatment/outcome
Malignant (Congenital mesoblastic nephroma is most common renal tumor in neonates, benign) Renal Mass. hematuria, htn, resection/nephrectomy, 80% of patients are diagnosed between 1 and 5 years of age. On ultrasonography, the tumor appears as a smooth, well-delineated mass of uniform texture. Assc with Beckwith-Wiedmann excellent prognosis most common intra-abdominal tumor of childhood genes on the 11th and 16th chromosomes.
30
Cardiac rhabdomyomas: benign/malignant clinical features diagnosis treatment/outcome
benign cardiac masses (mc in ventricles or septum), association with TS, arise in utero from cardiac striated muscle natural course is regression. If very large, surgical resection, brain MRI and genetic testing for TS observation, regression, f/u for TS
31
neuroblastoma: benign/malignant clinical features diagnosis treatment/outcome
malignant (mc malignant neonatal tumor, 2nd most common neonatal tumor after teratoma) adrenal mass, hepatomegaly, blue skin nodules, stage IV-S (s = special, spontaneous regression) common in neonates biopsy to stage, urine hva/vma, MIBG scan to evaluate for mets. N-MYC amplification in unfavorable. observation, good prognosis, spontaneous resolution from neural crest cells. most commonly in adrenal glands or along sympathetic chain. abdomen. spread to liver and skin, also bone marrow, bone, lung, cns.
32
hemangiomas: benign/malignant clinical features diagnosis treatment/outcome
benign varied, associateions with internal hemangiomas if large \> 5cm or \> 5# perform additional imaging including liver. Assc w/ PHACES syndrome: posterior fossa malformation/hemangioma/arterial-aortic abnormalities/cardiac defects/eye abnormalities/sternal cleft-supraumbilical raphe syndrome normally regresses, proponalol is 1st line, sirolimus (rapamycin) is an mTOR inhibitor, also promising against massive hemangiomas
33
teratoma: benign/malignant clinical features diagnosis treatment/outcome
90% benign midline mass, usually sacrococcygeal\>mediatstinum. Most common neonatal tumor. afb and b-hcg in immature termatomas or with germ cell components surgical resection, good outcome
34
langerhans cell histiocytosis (macrophages): benign/malignant clinical features diagnosis treatment/outcome
malignant scaly ezcematous rash, lytic bone lesions, birbreck granules (tennis racket shaped organelles) biopsy, cell stain positive for cd1a or cd207, may get DI if multisystem disease, need chemo (steroids, vinblastine), otherwise obs/ressection, BRAF inhibitor therapy
35
transient abnormal myelopoises (TAM) ## Footnote benign/malignant clinical features diagnosis treatment/outcome
formerly known as TMD (transient myeloproliferative disorder) malignant but transient symptoms similar to leukemia but only see in tri 21 elevated wbc, leukemia cutis (skin nodules with leukemia cells) observer, increased 25% lifetime risk of AML
36
leukemia benign/malignant clinical features diagnosis treatment/outcome
aml \> all malignant skin nodules, hsm, bruising/bleeding elevated wbc, anemia, thromboctopenia chemo. very poor prognosis.
37
is unconjungated bilirubin hydrophobic or hydrophilic?
Unconjugated bili is hydrophobic. It binds to albumin in plasma. It can cross the placenta.
38
Which enzyme converts heme into biliverdin?
Heme oxygenase
39
Which enzyme converts biliverdin into bilirubin?
Bilrubin reductase
40
What does glucuronyl transferase do?
UDPGT catalyzes binding of glucuronic acid to bilirubin, making it water soluble so it can be excreted in bili and making it harder to get absorbed intestinally.
41
What does beta glucuronidase do
Deconjugates bilirubin --\> then gets reabsorbed in intestine. AKA enterohepatic circulation.
42
which form of bilirubin crosses over the placenta
Unconjugated bilirubin (hydrophobic). Conjugated bili and biliverdin do not cross.
43
1 g of Hgb gives how much bilirubin?
35 mg of bilirubin
44
What are sources of bilirubin?
~80% RBC, the rest is from myoglobin, cytochromes, catalase, peroxidase, free heme, early RBC in marrow
45
What is a direct measurement of hemolysis?
ETCO (carbon monoxide) - 1:1 for Heme break down
46
What does tin mesoporphyrin do?
inhibit heme oxygenase
47
what does bilirubin get converted into by natural gut flora?
urobilinogen to be excreted
48
What MCHC and MCHC:MCV is indicative of hereditary spherocytosis
MCVC \>/= 36, MCHC:MCV \>/= 0.36
49
What are two factors in hyperbilirubinemia that are associated with lower iq?
positive DAT and length of exposure to high levels (matter of days)
50
What is ligandin?
ligandin is a carrier protein that helps transport bilirubin-albumin complex into hepatocyte for conjugation.
51
what is a risk factor of exchange transfusion?
hypocalcemia from the citrate in PRBC
52
In kernicterus, how is IQ effected?
usually normal IQ. Can have renal tubular necrosis, pancreatic necrosis and SNHL, dental dysplasia, abnormal upward gaze and intestinal necrosis.
53
what is the normal blue light range for phototherapy
420-290 Um
54
what is the configuration of lumirubin
converted from 4z-15z to E configuration
55
when does breast milk jaundice vs breast feeding jaundice happen?
BM jaundice is after 7 days of life, due to extra b glucuroindase. Breast feeding jaundice is in first 3-5 days due to dehydration.
56
Kinds of common Liver tumor
the most common neonatal liver tumor is infantile hemangioma, accounting for approximately 60% of cases. Mildly elevated afp, endothelial glut 1+. usually regress. Mesenchymal hamartoma is second in prevalence, accounting for approximately 23% of cases. usually has cysts lined with bile duct epithelium. primary hepatoblastoma is third, accounting for approximately 17% of cases. Most commonly presents in childhood. assc with BWS, aicardi, familial adenomatous polyposis coli, tri 18
57
Describe G6PD: impacted population, presentation, pathopysiology
Disproportionately impacts african american babies. Presents as hemolytic jaundice, may jaundice may be due to poor conjugation. Can be induced by nitrofurantoin, fava beans. X linked.
58
What is Gilbert Syndrome
Gilbert syndrome is associated with impaired bilirubin uptake and impaired UDP-glucuronosyl transferase conjugation of bilirubin. Elevated uncojugated hyperbilirubinemia.
59
What is pyruvate kinase deficiency?
the second most common enzymatic cause of neonatal hyperbilirubinemia and hemolytic anemia Pyruvate kinase is a glycolytic enzyme responsible for conversion of 2-phosphoenolpyruvate to pyruvate and production of ATP. If activity is reduced because of insufficient protein or inadequate functioning, energy is not available to maintain water and potassium content; the red blood cells become rigid and lyse as they travel through the spleen and reticuloendothelial organs.
60
what is hgb M
in methemoglobinemia, Fe 2+ (ferrous) is oxidized to Ferric 3+ and unable to reversibly bind oxygen --\> when methemoglobin leves \> 10%. HbM --\> doesn't bind o2 well. remaining Hb bind tightly to o2 and dont release o2 well. Methemoglobinemia I: cyctochrome b5 reductase (methemoglobin reductase) absent in RBC Meth. II: meth reductase absent in all cells, most severe. No ability to reduce Fe3+