Anemia Part II Flashcards
What are RBCs made from?
Iron, Folic Acid, Vitamin B12
RBC Measures
- Hgb, Hct, RBC: Low vs High
Hemoglobin: Low = anemia, High = polycythemia
Hematocrit: Low = anemia, High = polycythemia
RBC: Low = anemia, High = thalassemia
Absolute Reticulocyte Count
(RBC count x % reticulocytes)/100
< 100,000/microL reticulocytosis can be excluded
Classification of Anemia (3)
By onset
By pathophysiology (Hypoproliferative (RR<40,000) Proliferative (RR>100,000))
By morphology
Anemia Classification (causes)
- Micro
- Macro
- Normo
Micro –> almost always due to decreased hemoglobin production
Macro –> usually from a defect in the maturation of RBCs
Normo –> usually from decreased production or increased destruction of RBCs
Microcytic Anemias
(4)
Iron Deficiency
Anemia of Chronic Disease
Thalassemias
Sideroblastic Anemia
Macrocytic Anemias
- Megaloblastic (3)
Megaloblastic:
- Vitamin B12 deficiency
- Folate Deficiency
- Drug-related
Macrocytic Anemias
- Non-Megaloblastic (4)
- Hypothyroidism
- Liver Disease
- Alcoholism
- Myelodysplastic Syndromes
Normocytic Anemias
- Hemolytic (2 types; 3 subtypes)
Hemolytic
-
Intrinsic
- Membrane Defects
- Enzyme deficiencies
- Hemoglobinopathies -
Extrinsic
- Autoimmune (warm and cold antbody mediated)
- Alloimmune
- Nonimmune (splenomegaly, physical trauma, inefctions)
Normocytic Anemias
- Non-Hemolytic (4)
- Acute blood loss
- Aplastic anemia
- Anemia of chronic disease
- Chronic renal insufficiency
Macrocytic Anemia
- Causes (Name the main 3 of the 14 total)
BIG FAT RED CELLS
B- B12 malabsorption
I- Inherited
F-Folic acid deficiency
Anemia
- Objective Findings
Tachycardia, Tachypnea, Weight Loss
Pale Skin or Mucous Membranes, Nail Changes
Systolic Murmur (may be heard)
Vibratory Sense Loss (B12 deficiency)
Jaundice
Megaloblastic Anemia
- 3 key findings
MCV > 100 fL
Macroovalocytosis
Hypersegmented neutrophils (5+ lobes)
Vitamin B12
- Total Body Stores
- Daily Requirement
- Source
- Site of Absorption
- Complications (if deficient)
Total Body Stores: 2-5 mg
Daily Requirement: 1-3 mcg
Source: Animal sources only
Site of Absorption: Terminal Ileum
Complications (if deficient): Megaloblastic anemia, Neurologic Abnormalities
Folate (Folic Acid)
- Total Body Stores
- Daily Requirement
- Source
- Site of Absorption
- Complications (if deficient)
Total Body Stores: 5-10 mg
Daily Requirements: 50-100 mcg
Source: Animal products, Leafy Vegetables, Nuts, Beans, Fruit
Site of Absorption: Proximal jejunum
Complications (if deficient): Megaloblastic Anemia, Neural Tube Defects
How long does it take to become B12 deficient? Folate deficient?
B12 deficiency = 3-4 years
Folate = 3-4 months
Vitamin B12 (Cobalamin) Deficiency
- Causes
- Incidence
- Prevalence
- Causes interference in DNA synthesis (via methylmalonic acid to succinyl Coa and homocystine to methionine reactions)
- Incidence: women over 60 y/o
- Prevalence: highest in African and Asian countries
What is the most common cause fo Vitamin B12 deficiency?
What causes it?
Pernicious Anemia
-Due to autoantibodies against Intrinsic Factor or atrophy of the cells that produce it
Other Causes of B12 deficiency (6)
Diet (Vegans)
Malabsorption
- Gastrectomy
- Zollinger Ellison Syndrome
- Ileal Disease (Crohn’s)
- Drugs (Meformin, Prolonged PPIs for GERD/PUD)
- Fish tapeworm
B12 Deficiency
- Specific Symptoms
- PE Findings
- Neurologic –> Paresthesias, Atazia, Change in Mental Status
- PE Findings –> Decreased Position and Vibratory Sense, Disturbances of Vision, Taste, and Smell, Romberg’s Sign, Babinski’s Sign, Neuropathy
B12 Deficiency
- Diagnostic Labs (6)
- Need CBC and Retic Count
- Increased MCV
- Decreased Retic Count
- Low B12 level, High serum Methylmalonic Acid and Homocysteine levels (Normal B12 level is 160-1000 ng/L)
- Peripheral Blood Smear –> Macrocytic RBCs, Anisocytosis, Poikilocytosis, and Hypersegmented Neutrophils
- Bone Marrow may show megaloblasts, erythroid platelets
B12 Deficiency
- Treatments
- Responses
- FIND THE CAUSE
- B12 1000 mcg SC or IM weekly x1 month, then monthly
- Sublingual or oral B12 1-2 mg PO if not due to malabsorption
- Intranasal gel - ***Hypokalemia*** (watch for this)
Response: Bone marrow becomes normoblastic in 12 hours, Reticulocytosis in 3-5 days, Hgb normalizes in 2 months
B12 Deficiency
- Implications (3)
- Demyelination of the posterior spinal cord can occur, causing spastic ataxia and dementia
- Can lead to infertility in both men and women
- Can cause cervical smear abnormalities
***Post Gastrectomy Patients***
ALL total gastrectomy patients need B12 supplementation
10-15% of partial gastrectomy patients will develop deficiency
Pernicious Anemia
- What is it?
- Results
- Most common
- Highly associated with
- Increased incidence of
- Average age of onset
- What is it? –> Hereditary Autoimmune disorder-immune-mediated atrophy of gastric parietal cells
- Results –> Absent gastric acid/intrinsic factor
- Most common –> among Northern Europeans/African Americans
- Highly associated with –> Autoimmune Disorders
- Increased incidence of –> Intestinal Type Gastric Cancer/Gastric Carcinoid Tumors
- Average age of onset –> 60 years old
Pernicious Anemia
- Diagnostic Labs
Parietal cell and Intrinsic Factor antibody positive (90% and 70%)
Serum Gastrin level is high; Serum Pepsinogen 1 level is low (90%)
Gastric biopsy shows atrpohy of all layers of the body and fundus with absence of parietal and chief cells and replacement by mucous cells
Subclinical B12 Deficiency
- What is it?
- Elevated?
- Treatment
- Borderline Serum B12 level
- Elevated homocysteine or methylmalonic acid levels
- No clear guidelines for treatment
- MVI with B12 is not sufficient
- 500-1000 mcg daily is lowest dose sufficient to correct
***Basically treated as if they have B12 deficiency***
Folate Deficiency Anemia
- Main Causes (5)
- Inadequate Dietary Intake –> Alcoholism, Elderly
- Increased needs –> pregnancy, lactation, prematurity, hemolytic anemia, exfoliative dermiatitis, RA, Crohn’s, Dialysis patients
- Malabsorption –> Celiac disease, IBS
- Drugs –> Methotrexate, Trimethoprim, Dilantin, OCPs
- Liver Disease
Folace Deficiency Anemia
- Signs/Symptoms
- Objective Findings
- Similar to B12 deficiency, but no neurologic abnormalities
- Fatigue, weight loss, lightheadedness, abdominal pain
- Neural Tube Defects (pregnant women) - Objective Findings –> Pallor, Glossitis, Jaundice
Folate Deficiency
- Diagnostic Labs
- Low Hgb with macrocytosis
- Low serum (2-15 mcg/L) and RBC folate level
- Peripheral smear –> Hypersegmented neutrophils
- High homocysteine levels
- Normal or low B12 level
- Normal methylmalonic acid
Folate Deficiency
- Treatment
- Consume foods rich in folate
- Supplement Folate (1-5 mg/day) orally
- Correction may take up to 8 weeks, common to continue longer
Aplastic Anemia
- Causes
- Results
- Bone marrow failure caused by suppression or injury to stem cells
- Bone marrow fails to produce mature blood cells - Pancytopenia results
Aplastic Anemia
- Causes (most common)
- Autoimmune: Idopathic, SLE
Congenital
Chemotherapy, Radiotherapy
Toxins
Drugs
Posti-viral Hepatitis
Pregnancy
Paroxysmal Nocturnal Hemoglobinuria
Aplastic Anemia
- Symptoms (3)
- PE Findings (3)
Symptoms:
- Weakness/Fatigue (Anemia)
- Bacterial/Fungal Infections (Neutropenia)
- Mucosal/Skin Bleeding/Petechiae (Thrombocytoepnia)
PE Findings:
- Pallor, Petechiae, Purpura
- HSM (in advanced disease) Hepatosplenomegaly
- ***Lymphadenopathy and bone pain should NOT BE PRESENT***
(This is actually suggestive of CANCER)
Aplastic Anemia
- Diagnostic Labs
Pancytopenia (more severe = worse prognosis)
Bone Marrow Biopsy –> Will appear hypocellular (hardly any cells present)
Aplastic Anemia
- Treatment (Mild vs Severe)
Mild –> Supportive Care
(Not too many transfusions to avoid sensitizing potential transplant candidates)
Severe –> Bone Marrow Transplant
What lab findings help you differentiate between Vitamin B12 Deficiency and Folate Deficiency?
Serum Folate:
B12 Deficiency –> Normal
Folate Deficiency –> Low
Methylmalonic Acid:
B12 Deficiency –> High
Folate Deficiency –> Normal
