Heme & Onc

Question 0

Causes of hypochromic, microcytic anemia:

Answer 0

1: Fe deficiency (blood loss, malnutrition or pregnancy)

2. Thalassemias (alpha, beta)
3. Sideroblastic anemia (problem w/ porphyrin ring)
   a) hereditary: x-linked, d-ALA sythase mut for heme synth
   b) reversible: (from toxicity) Lead, EtOH, isoniazid

Question 1

Alpha vs. beta thalassemia

Answer 1

Alpha thal: 3 or 4 gene deletion (4 genes contribute) => hydrops fetalis
*Asians: cis mut; African: trans mut.
Beta thal: point mutation @ splice or promoter site (2 genes). +HbA2
*esp. mediterraneans. onset ~6 wks after birth

Question 2

Signs of Lead poisoning (“LEAD”)

Answer 2

• Lead lines (on gingivae & long bone metaphyses)
• Encephalopathy
• Abdominal colic & sideroblastic Anemia
• wrist and foot Drop (neuro, & Bx changes)
  also: basophilic stippling of RBCs on smear

Question 3

Causes of megaloblastic, macrocytic anemia

Answer 3

(megaloblastic bc impaired DNA synth => nucleus maturation delayed)

1. folate (B6) def.
   * high homocysteine level
2. Cobalamin (B12) def. (ie: pernicious anemia)
   * high homocysteine AND methylmalonic acid
3. orotic aciduria

Question 4

Case:
Woman with SLE and hypercoagulability.
why? what lab abnormalities?

Answer 4

“Anti-Phospholipid Ab syndrome” = auto-immune hypercoagulability due to autoimmune disease mediators (lupus anticoagulant or anti-cardiolipin Ab)
* prolonged baseline aPTT
=> venous/arterial thrombosis, or frequent fetal loss

Question 5

Why bone lysis with multiple myeloma?

Answer 5

Neoplastic cells release IL-1 & IL-6 => bone reabsorption

IL-1 stimulates osteoclasts