Page 302 - Clinical Hematology_ Theory _ Procedures ( PDFDrive )

286 PART 4 ■ Erythrocyte Disorders

TABLE 15.2 Megaloblastic Anemia Testing *

Basic Testing Level Follow -Up Testing Level Interpretation

Vitamin B 12 >400 pg/mL Not PA

>400 pg/mL if neurologic Serum methylmalo- May con rm B
12
symptoms nic acid (MMA) and de ciency

homocysteine

100–400 pg/mL Serum methylmalonic <0.4 µmol/L Not PA

acid (MMA)

≥0.4 µmol/L PA

Optional testing IF-blocking

antibody, parietal cell antibody,
IgG, and gastrin levels

<100 pg/mL Optional testing IF-blocking PA

antibody, parietal cell antibody,

IgG, and gastrin levels

Folate Low Folate de ciency

Low or normal RBC folate

* Presence of macrocytic red blood cells.

PA, pernicious anemia.

T mm S m m m . A

m B - m m . T LDH

IF m -

. A -IF m m m .

IF. A x m % I m , m m -

m . M - m . C

m ( %) . I m ( m B ) -

, m m - m .

. L -

m - Treatment and Monitoring Therapy

m m .

A , (HC ) T m m B

m , m m . m m j µ m

A HC B m . T m

TABLE 15.3 Vitamin B Assays Re ect Conditions
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Normal Reference De ciency

Assay Range Negative Balance Depleted Stores in Tissues Anemia

Serum cobalamin (pg/mL) 200–900 150–500 100–300 50–250 50–250

Serum MMA (µmol/L) <0.4 <0.4 <0.4 0.4–20 1–20

Hypersegmentation of None None None 1+ 2+

neutrophils

MCV (fL) 80–95 80–95 80–95 90–110 100–130

Hemoglobin (g/dL) 12–15 12–15 12–15 12–15 <12

MCV mean cell volume; MMA, methylmalonic acid; RBC, red blood cell
,