Wallach's Interpretation of Diagnostic Tests: Pathways to Arriving at a Clinical Diagnosis (933 page)

Commonly Used Cluster of Differentiation (CD) Antigens

FOLATE, SERUM AND ERYTHROCYTES (RBCs)

   Definition

   Folate refers to all derivatives of folic acid. Folate is an essential vitamin present in a wide variety of foods such as dark leafy vegetables, citrus fruits, yeast, beans, eggs, and milk. Folate is vital to normal cell growth and DNA synthesis. A folate deficiency can lead to megaloblastic anemia and ultimately to severe neurologic problems. Folate levels in both serum and RBCs are used to assess folate status. The serum folate level is an indicator of recent folate intake. RBC folate is the best indicator of long-term folate stores. A low RBC folate value may indicate a prolonged folate deficiency. Other names: vitamin B
₉
.

   
Normal range:

   Serum folate: >6.5 ng/mL

   RBC folate: 280–903 ng/mL

   Use

   Evaluation of folate deficiency

   Interpretation

Increased In

   Blind loop syndrome