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Test ID ACASM Pernicious Anemia Cascade, Serum

Useful For

Diagnosis of pernicious anemia


Diagnosis of vitamin B12 deficiency-associated neuropathy

Special Instructions

Method Name

Immunoenzymatic Assay

Reporting Name

Pernicious Anemia Cascade

Specimen Type


Ordering Guidance

Ask patients if they have received a vitamin B12 injection or radiolabeled vitamin B12 injection within the last 2 weeks. Patient results will not reflect deficiency or malabsorption after recent B12 injection. If patient has received such an injection within the past 2 weeks, this test should not be ordered.

Specimen Required

Patient Preparation:

1. This test should not be performed on patients who have received a vitamin B12 injection or radiolabeled vitamin B12 injection within the previous 2 weeks.

2. Patient should be fasting for 8 hours.

3. If medically feasible, proton pump inhibitor (omeprazole, lansoprazole, dexlansoprazole, esomeprazole, pantoprazole, and rabeprazole) therapy should be discontinued 1 week before measurement of serum gastrin levels.

4. Drugs that interfere with gastrointestinal motility (eg, opioids) should be discontinued for at least 2 weeks before serum gastrin testing.


Preferred: Red top

Acceptable: Serum gel

Specimen Volume: 4 mL

Collection Instructions:

1. Divide specimen into 3 plastic vials, 1 containing 1 mL (label as PAGAS), 1 containing 1.5 mL (label as PAMMA), and 1 containing 1.5 mL (label as B12PA).

2. Band specimens together.

Specimen Minimum Volume

2.3 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Serum Frozen (preferred) 30 days
  Refrigerated  24 hours

Reference Values

180-914 ng/L

Day(s) Performed

Monday through Saturday

Performing Laboratory

Mayo Clinic Laboratories in Rochester

CPT Code Information

82607-Vitamin B12 assay

82941-Gastrin (if appropriate)

83921-MMA (if appropriate)

86340-IFBA (if appropriate)

LOINC Code Information

Test ID Test Order Name Order LOINC Value
ACASM Pernicious Anemia Cascade 2132-9


Result ID Test Result Name Result LOINC Value
B12PA Vitamin B12 Assay, S 2132-9

Test Classification

This test was developed, and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the US Food and Drug Administration.

Reflex Tests

Test ID Reporting Name Available Separately Always Performed
IFBPA Intrinsic Factor Blocking Ab, S Yes, (order IFBA) No
MMAPA Methylmalonic Acid, QN, S Yes, (order MMAS) No
GASTR Gastrin, S Yes, (order GAST) No

Testing Algorithm

If the vitamin B12 concentration is less than 150 ng/L, then the intrinsic factor blocking antibody (IFBA) test is performed at an additional charge.

If IFBA result is negative or indeterminate, then the gastrin test is performed at an additional charge.

If the vitamin B12 concentration is 150 to 400 ng/L, then the methylmalonic acid (MMA) test is performed at an additional charge.

If the MMA result is greater than 0.40 nmol/mL, then the IFBA test is performed at an additional charge.


For more information, see Vitamin B12 Deficiency Evaluation.

Report Available

Same day/1 to 4 days

NY State Approved



If not ordering electronically, complete, print, and send a Benign Hematology Test Request Form (T755) with the specimen.