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Test Code NEZPP Zinc Protoporphyrin, Blood

Useful For

Evaluating iron deficiency


Monitoring treatment and environmental intervention of chronic lead poisoning

Method Name


Reporting Name

Zinc Protoporphyrin, B

Specimen Type

Whole blood

Specimen Required

Patient Preparation:

High concentrations of gadolinium and iodine are known to interfere with most metals tests. If either gadolinium- or iodine-containing contrast media has been administered, a specimen should not be collected for 96 hours.


Metal Free B-D Tube (EDTA), 6 mL (T183)

Metal Free (Lead only) EDTA Tube, 3 mL (T615)

Microtainer (EDTA) Tube, 0.5 mL (T174)

If ordering the EDTA trace element Vacutainer tube from BD, order catalog #368381.


Preferred: Royal blue-top BD Vacutainer Plus with EDTA blood collection tube (T183)

Acceptable: Tan-top (lead only) BD Vacutainer Plus with EDTA blood collection tube (T615) or BD Microtainer with EDTA (T174) or royal blue-top Monoject trace element blood collection tube

Specimen Volume: 1 mL

Collection Instructions:

1. See Trace Metals Analysis Specimen Collection and Transport in Special Instructions for complete instructions.

2. Send specimen in original tube.

Specimen Minimum Volume

0.3 mL

Specimen Stability Information

Specimen Type Temperature Time
Whole blood Refrigerated 28 days

Reject Due To


Mild reject; Gross reject


Mild reject; Gross reject





Clinical Information

The porphyrins are intermediaries in the heme synthesis pathway. When iron is not available for heme synthesis (eg, iron deficiency), zinc protoporphyrin (ZPP) accumulates within RBCs. Lead inhibits several enzymes in the heme synthesis pathway and causes increased levels of RBC ZPP.


ZPP is a biological marker of lead toxicity and was previously used, in conjunction with blood lead assays, to screen for lead poisoning in children. However, because of poor sensitivity and specificity, ZPP is no longer recommended for lead screening in children. However, ZPP remains a useful tool for monitoring treatment of individuals with confirmed elevated lead levels.

Reference Values

<70 mcmol ZPP/mol heme


An elevated zinc protoporphyrin (ZPP) indicates impairment of the heme biosynthetic pathway.


Elevated ZPP levels in adults may indicate long-term (chronic) lead exposure or may be indicative of iron deficiency anemia or anemia of chronic disease.


High concentrations of gadolinium and iodine are known to interfere with most metals tests. If either gadolinium- or iodine-containing contrast media has been administered, it is suggested a specimen not be collected for 96 hours.

Method Description

Zinc protoporphyrin is measured on the Helena ProtoFluor-Z hematofluorometer using a multichannel front surface photofluorometer. When the sample is exposed to light, zinc protoporphyrin (ZPP) is excited and emits light. A second lens/filter system collects, filters, and focuses the light onto a photomultiplier tube (PMT). The PMT produces a current level in response to the light reaching it, which is proportional to the ZPP:heme ratio. During the reading, over 1,000 light-level readings are taken and averaged by the microcomputer and a value is displayed in mcmol ZPP/mol heme.(Instruction manual: Helena Laboratories ProtoFluor-Z Hematofluorometer 9/2013)

Day(s) and Time(s) Performed

Monday through Friday; 5 pm

Analytic Time

1 day

Specimen Retention Time

2 weeks

Performing Laboratory

Mayo Medical Laboratories in Rochester

Test Classification

This test has been modified from the manufacturer's instructions. Its performance characteristics were determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.

CPT Code Information


LOINC Code Information

Test ID Test Order Name Order LOINC Value
NEZPP Zinc Protoporphyrin, B 29763-0


Result ID Test Result Name Result LOINC Value
300009 Zinc Protoporphyrin, B 29763-0


1. Lead/Heavy Metals Reporting Form (T491) in Special Instructions

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