Hematological and select immunological disorders Flashcards
True/false: Symptoms of anemia seldom occur unless hemoglobin levels decrease to less than 10 g/dL
True
Anemia diagnostic testing
First line test → CBC
- Note hemoglobin, hematocrit, and RBC values
- What is the RBC size (MCV)
- Microcytic (low MCV) → impaired hemoglobin synthesis
- Ex: IDA, thalassemia
- Will also have low MCH and MCHC
- Macrocytic (high MCV) → impaired RNA and DNA synthesis
- Ex: folic acid and vitamin b12
- Normochromic (MCH) and normal MCHC
- Normocytic
- Ex: acute blood loss, anemia of chronic disease
- What is the hemoglobin content (color) of the cell (MCH or MCHC)
- What is the RDW (RBC distribution width)
- Degree of variation in RBC size
- What is the % of reticulocytes
- Body attempts to create new cells (reticulocytes) in anemia
- Microcytic (low MCV) → impaired hemoglobin synthesis
What is the RBC size?
- Microcytic vs normocytic vs macrocytic
Microcytic → MCV less than 80
Normocytic → MCV 80-96
Macrocytic → MCV greater than 96
What is the RBCs hemoglobin content (MCH and MCHC)?
- Normochromic vs hypochromic
Normochromic → MCHC 31-37
Hypochromic → MCHC less than 31 (pale)
- Microcytic and hypo chromic go together
Common causes of iron deficiency anemia (IDA)
Chronic blood loss
- Occult GI blood loss (oozing gastritis or malignancy) in males
- Heavy menstrual flow in women
Iron deficiency anemia (IDA) diagnostic testing
- Low to normal hemoglobin, hematocrit, RBC count
- RDW >15% (increasing variation)
- Low serum iron level
- Elevated TIBC
- if more transferrin is available for binding, TIBC increases reflecting iron deficiency
- Iron saturation <15%
- Low serum ferritin level
IDA treatment
- Iron supplementation (ferrous gluconate or sulfate), 50-60 mg
- Avoid enteric coated supplements
- Twice daily, no sooner than ever 6 hours, for 3-6 months
- Taken on empty stomach
- Ascorbic acid (vitamin C) enhances iron absorption
- Taken at same time as iron supplement
What medications decrease iron absorption?
- Antacids - separate use by 2+ hours
- Caffeine - separate use by 2+ hours
- Levodopa - separate meds by as much time as possible
- Histamine-2 receptor antagonist
- PPI
Iron supplementation will effect absorption of which medication classes?
- Fluoroquinolones - separate by 6+ hours
- Levodopa
- ACE inhibitors - separate use by 2+ hours
- Tetracyclines - separate by 3-4+ hours
- Levothyroxine - take levothyroxine 2+ hours before or 4 hours after iron dose
Lab evaluation during IDA resolution
- Reticulocytes at 1-2 weeks to ensure marrow response
- Hemoglobin at 6 weeks to 2 months to ensure recovery
- Ferritin at 2 months after measure of normal hemoglobin (or 4 months after initiation of iron therapy)
Normocytic (MCV 80-96), normochromic anemia with normal RDW
- Most common etiology?
Acute blood loss, anemia of chronic disease
Microcytic (MCV <80), hypo chromic anemia with elevated RDW
- Most common etiology
IDA
Microcytic (MCV <80), hypo chromic anemia with normal RDW
- Most common etiology
Alpha or beta thalassemia
Macrocytic (MCV >96), normochromic anemia with elevated RDW
- Most common etiology
- Vitamin b12 deficiency
- Pernicious anemia
- Folate deficiency
What is thalassemia?
Genetically based blood condition wherein the body makes an abnormal hemoglobin form (alpha and beta)
- Consider genetic testing if thal minor or thal trait
What are the two forms of macrocytic anemia?
- Vitamin b12 deficiency
- Folic acid deficiency
Folic acid deficiency anemia diagnostic testing
Macrocytic, normochromic anemia with elevated RDW
- Serum folic acid and vitamin b12
- Can follow up with serum homocysteine (elevated for both) and MMA (elevated in vitamin b12 deficiency only)
Folic acid deficiency anemia treatment and management
- Folate rich diet
- Supplementation (1 mg/day)
- If planning to become pregnant, 0.4 mg/day for 3 months before conception
- If history of previous neural tube defect, increase to 4 mg/day for 3 months and continue through first 12 weeks of pregnancy
True/false: The term ‘pernicious anemia’ is usually given to vitamin b12 deficiency secondary to lack of intrinsic factor
True - When vitamin b12 is ingested orally, it binds with intrinsic factor (glycoprotein produced by gastric parietal cells)
What two medications can limit dietary vitamin b12 absorption?
PPIs and metformin
Pernicious anemia clinical presentation
Slowly progressive with vague signs and symptoms
- Weakness
- Sore tongue with absent papillae
- Anorexia with unintended weight loss
- GI disturbance
Vitamin b12 anemia clinical presentation
Neuropathy
- Paresthesia
- Weakness
- Clumsiness
- Unsteady gait
- New onset MS change (forgetfulness)
- Hypoactive DTR
- Tachycardia
Vitamin b12 anemia diagnostic testing
Macrocytic, normochromic anemia with elevated RDW
- Low serum cobalamin (b12)
- Folic acid deficiency
Vitamin b12 anemia treatment and management
- Parenteral vitamin b12 preferred over oral
- Will be needed for the rest of the patient’s life
- Monitor for drug interactions
- Can start empiric supplementation with either b12 or folic acid if unsure which is cause
What medications can effect vitamin b12 absorption?
- Colchicine
- Potassium supplements
- Ascorbic acid (vitamin C)
- PPI
Anemia of chronic disease diagnostic testing
Diagnosis of exclusion
- Serum iron, transferrin, reticulocyte count, ferritin (for IDA)
Anemia of chronic disease treatment and management
- Treatment of underlying inflammatory disease
- In chronic kidney disease (eGFR <45), erythropoietin production is reduced
- Epoetin alfa SQ or IV
- Iron therapy
Anaphylaxis clinical presentation
- Acute onset of reaction with involvement of skin, mucosal tissue, or both and at least one of the following:
- Respiratory compromise
- Reduced BP
- Symptoms of end organ dysfunction
- 2+ of the following occur rapidly after exposure to a likely allergen:
- Involvement of skin/mucosal tissue
- Respiratory compromise
- Reduced BP or associated symptoms
- Persistent GI symptoms
- Reduced BP after exposure to a known allergen
