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Test Code PIPA Pipecolic Acid, Serum

Reporting Name

Pipecolic Acid, S

Useful For

Differentiating between disorders of peroxisomal biogenesis (eg, Zellweger syndrome) and disorders with loss of a single peroxisomal function

 

Detecting abnormal elevations of pipecolic acid in serum

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Specimen Type

Serum


Necessary Information


Patient's age is required.



Specimen Required


Patient Preparation: Fasting 12 hours or more. (Collect specimens from infants and small children just before next feeding)

Supplies: Sarstedt Aliquot Tube, 5 mL (T914)

Collection Container/Tube:

Preferred: Serum gel

Acceptable: Red top

Submission Container/Tube: Plastic vial

Specimen Volume: 1.5 mL

Collection Instructions: Centrifuge and aliquot serum into plastic vial.


Specimen Minimum Volume

1 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Serum Frozen (preferred) 94 days
  Refrigerated  14 days

Reference Values

<6 months: ≤6.0 nmol/mL

6 months-<1 year: ≤5.9 nmol/mL

1-17 years: ≤4.3 nmol/mL

≥18 years: ≤7.4 nmol/mL

Day(s) Performed

Tuesday

Test Classification

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

CPT Code Information

82542

LOINC Code Information

Test ID Test Order Name Order LOINC Value
PIPA Pipecolic Acid, S 32334-5

 

Result ID Test Result Name Result LOINC Value
81326 Pipecolic Acid, S 32334-5
29962 Interpretation 59462-2
29964 Reviewed By 18771-6

Genetics Test Information

In the newborn period, pipecolic acid levels are more likely to be abnormal in urine than in plasma or serum. Abnormal levels of pipecolic acid should be interpreted together with the results of other biochemical markers of peroxisomal disorders, such as plasma C22-C26 very long-chain fatty acids, phytanic acid, pristanic acid, red blood cell plasmalogens, and bile acid intermediates.

Clinical Information

Pipecolic acid (PA) is an intermediate of lysine metabolism and is oxidized in the peroxisomes by the enzyme L-pipecolate oxidase. In peroxisome biogenesis disorders (eg, Zellweger syndrome), the activity of this enzyme is lost, resulting in an increase in pipecolic acid levels. In contrast, in peroxisomal disorders involving single enzyme deficiencies such as D-bifunctional protein deficiency, PA is not elevated; therefore, PA analysis is useful for differentiating between these 2 groups of disorders.

 

Increased pipecolic acid levels may also be seen in alpha-aminoadipic semialdehyde dehydrogenase deficiency (pyridoxine-dependent epilepsy), hyperlysinemia types 1 and 2, and defects in proline metabolism.

 

Theoretically, a defect in L-pipecolate oxidase can exist, and several cases of hyperpipecolic acidemia have been reported, but a specific enzyme deficiency has not been described in any of the patients.

Interpretation

Elevated pipecolic acid levels are seen in disorders of peroxisomal biogenesis; normal levels are seen in disorders with loss of a single peroxisomal function.

 

Abnormal levels of pipecolic acid should be interpreted together with the results of other biochemical markers of peroxisomal disorders, such as plasma C22-C26 very long-chain fatty acids, phytanic acid, and pristanic acid (POX / Fatty Acid Profile, Peroxisomal [C22-C26], Serum); red blood cell plasmalogens (PGRBC / Plasmalogens, Blood); and bile acid intermediates (BAIPD / Bile Acids for Peroxisomal Disorders, Serum).

Report Available

3 to 9 days

Specimen Retention Time

1 month

Reject Due To

Gross hemolysis OK
Gross lipemia OK
Gross icterus OK

Method Name

Gas Chromatography Mass Spectrometry (GC-MS)

Testing Algorithm

For more information see Epilepsy: Unexplained Refractory and/or Familial Testing Algorithm