I. Indications

  1. Low-cost clinic-based Iron Deficiency screening
  2. Lead Poisoning screening

II. Physiology

  1. Protoporphyrin converted to heme by ferrocheletase
  2. Lead inhibits ferrocheletase
    1. Protoporphyrin accumulates (ferrocheletase absent)
  3. Iron Deficiency results in impaired heme synthesis
    1. Protoporphyrin accumulates

III. Technique

  1. Hematofluorimeter measures Protoporphyrin

IV. Efficacy

  1. Iron Deficiency Anemia
    1. Identifies cases of Iron Deficiency prior to Anemia
    2. Non-specific test (see causes for increase below)
    3. Misses some cases of Iron Deficiency Anemia
      1. Perform concurrently with Hemoglobin
    4. Similar to Transferrin Saturation
      1. Marks similar timing in Iron Deficiency
  2. Lead Poisoning
    1. Correlated with blood lead level
    2. See normal values below

V. Interpretation

  1. Normal range: 16 - 65 ug/dl (adults)
  2. Overt Iron Deficiency Anemia: Protoporphyrin >100
  3. Lead levels correlated with Protoporphyrin
    1. Protoporphyrin 79: Blood lead level 29
    2. Protoporphyrin 147: Blood lead level 49
    3. Protoporphyrin 255: Blood lead level 79

VI. Increased

  1. Iron Deficiency Anemia
  2. Lead Poisoning
  3. Sideroblastic Anemia
  4. Chronic disease
  5. Hemolytic Anemia
  6. Erythropoietic protoporphyria

VII. References

  1. Bakerman (1984) Interpretive Lab Data, p. 449
  2. Kazal (2002) Am Fam Physician 66(7):1217-27 [PubMed] (or open in [QxMD Read])

Images: Related links to external sites (from Google)

Ontology: Protoporphyrins (C0033733)

Definition (MSH) Porphyrins with four methyl, two vinyl, and two propionic acid side chains attached to the pyrrole rings. Protoporphyrin IX occurs in hemoglobin, myoglobin, and most of the cytochromes.
Concepts Organic Chemical (T109) , Biologically Active Substance(T123)
MSH D011524
SnomedCT 51866008
English Protoporphyrins, 3,7,12,17-Tetramethyl-8,13-divinyl-2,18-porphinedipropionic Acid, protoporphyrins, PROTOPORPHYRIN, Protoporphyrins [Chemical/Ingredient], protoporphyrin, Protoporphyrin, Protoporphyrin (substance)
Swedish Protoporfyriner
Czech protoporfyriny
Finnish Protoporfyriinit
French Ooporphyrines, Protoporphyrines
Polish Protoporfiryny
Spanish protoporfirina (sustancia), protoporfirina, Protoporfirinas
German Protoporphyrine
Italian Protoporfirine
Portuguese Protoporfirinas

Ontology: Protoporphyrin.free (C0807523)

Concepts Clinical Attribute (T201)
English Protoporphyrin.free