Serum vitamin B12: 55 pg/ml (260-935); erythrocyte folate; 467 ng/ml (WNL)
Vitamin B12 deficiency:
Vitamin B12 deficiency:
Clinical:
Highly variable clinical presentation
Wide range of symptoms affecting various organ systems or asymptomatic
Common symptom related to anemia
Neurologic manifestations (demyelonization, followed by axonal degeneration, and neuronal death)
Blood Smear Morphology
Many oval macrocytes, occasional rnicrocytes, fragmented red blood cells, and teardrop forms.
Howell-Jolly bodies, basophilic stippling and nucleated red blood cells are often present.
Hypersegmentation of neutrophils (six or more lobes in one or more neutrophils).
Bone Marrow Morphology
Hypercellular, with erythroid precursors predominating.
Megaloblastic maturation, many mitotic figures
The granulocyte precursors : nuclear/cytoplasmic asynchrony
Megakaryocytes: large and hypersegmented
Serum Vitamin BI2, Serum Folate, and Red Cell Folate Determinations
The serum vitamin B12 level is a useful measure of vit B12 stores and is decreased in
anemias secondary to vit B12 deficiency. Decreased serum folate levels are typically
found in patients with megaloblastic anemia secondary to folate deficiency. However, RBC
folate quantitation is more reliable since serum folate levels fluctuate considerably with recent diet.
Decreased red cell folate concentration more accurately reflects tissue stores.
Serum Methylmalonic Acid and Homocysteine
Serum methylmalonic acid and homoocysteine are very sensitive for detecting intracellular vitamin BI2
Normal levels rule out a deficiency.
More specific for detecting vitamin B12 deficiency states than low serum B12 levels, which can be
decreased without evidence of deficiency.
Limitation: elevations in serum methylmalonic acid also seen in patients with renal dysfunction.. Serum
TESTS TO DETERMINE PATHOGENESIS OF VITAMIN 612 DEFICIENCY
A. Schilling Test
B. Serum Intrinsic Factor and Parietal Cell Antibodies
Highly variable clinical presentation
Wide range of symptoms affecting various organ systems or asymptomatic
Common symptom related to anemia
Neurologic manifestations (demyelonization, followed by axonal degeneration, and neuronal death)
Blood Smear Morphology
Many oval macrocytes, occasional rnicrocytes, fragmented red blood cells, and teardrop forms.
Howell-Jolly bodies, basophilic stippling and nucleated red blood cells are often present.
Hypersegmentation of neutrophils (six or more lobes in one or more neutrophils).
Bone Marrow Morphology
Hypercellular, with erythroid precursors predominating.
Megaloblastic maturation, many mitotic figures
The granulocyte precursors : nuclear/cytoplasmic asynchrony
Megakaryocytes: large and hypersegmented
Serum Vitamin BI2, Serum Folate, and Red Cell Folate Determinations
The serum vitamin B12 level is a useful measure of vit B12 stores and is decreased in
anemias secondary to vit B12 deficiency. Decreased serum folate levels are typically
found in patients with megaloblastic anemia secondary to folate deficiency. However, RBC
folate quantitation is more reliable since serum folate levels fluctuate considerably with recent diet.
Decreased red cell folate concentration more accurately reflects tissue stores.
Serum Methylmalonic Acid and Homocysteine
Serum methylmalonic acid and homoocysteine are very sensitive for detecting intracellular vitamin BI2
Normal levels rule out a deficiency.
More specific for detecting vitamin B12 deficiency states than low serum B12 levels, which can be
decreased without evidence of deficiency.
Limitation: elevations in serum methylmalonic acid also seen in patients with renal dysfunction.. Serum
TESTS TO DETERMINE PATHOGENESIS OF VITAMIN 612 DEFICIENCY
A. Schilling Test
B. Serum Intrinsic Factor and Parietal Cell Antibodies
Causes of Macrocytosis:
Megaloblastic anemia
Liver disease
Alcoholism
Reticulocytosis
Hypothyroidism
Arsenic or chlordane intoxication
Congenital dyserythropoietic anemia
Aplastic anemia
Myelodysplastic syndromes
Myeloproliferative disorders
Myeloid leukemias
Chemotherapy
Megaloblastic anemia
Liver disease
Alcoholism
Reticulocytosis
Hypothyroidism
Arsenic or chlordane intoxication
Congenital dyserythropoietic anemia
Aplastic anemia
Myelodysplastic syndromes
Myeloproliferative disorders
Myeloid leukemias
Chemotherapy