Mayo Test Catalog, (Sorted By Test Name) - Mayo Medical ...

PPFR
28116
PPFWE
31891
to normalize the PT in 1:1 mixing suggests presence of an inhibitor (eg, specific factor inhibitor,
lupus-like anticoagulant or antiphospholipid antibody, non-specific inhibitor). 2) Typically the addition of
patient plasma of 1/10 or 2/10 volume of normal plasma shortens the prolonged PT, at least halfway
toward the upper normal range, when there is a deficiency of 1 or more relevant coagulation factors.
Inhibition is implied by failure to significantly shorten the PT. 3) Additional coagulation testing may be
needed to define the cause of an unexplained prolonged PT (eg, other clotting time tests, coagulation
factor assays, testing for presence of a lupus-like anticoagulant). Mixing studies and such additional
testing may be included in consultative testing ("Coagulation Consultation").
Reference Values:
PROTHROMBIN TIME
9.5-13.8 seconds
INR
0.8-1.2
The INR is used only for patients on stable oral anticoagulant therapy. It makes no significant
contribution to the diagnosis or treatment of patients whose PT is prolonged for other reasons.
Protoporphyrins, Fractionation, Reflex
Reference Values:
Only orderable as part of a reflex test. For further information see PEE/88886 Porphyrin Evaluation,
Erythrocytes.
Protoporphyrins, Fractionation, Washed Erythrocytes
Clinical Information: Zinc-complexed protoporphyrin can be increased in erythrocytes in
association with: -Iron deficiency anemia (the most common cause of elevated zinc protoporphyrin)
-Chronic intoxication by heavy metals (ie, lead) or various organic chemicals -Hepatoerythropoietic
porphyria Noncomplexed (free) protoporphyrin is increased disproportionately in erythrocytes in cases
of erythropoietic protoporphyria. The following algorithms are available in Special Instructions:
-Porphyria (Acute) Testing Algorithm -Porphyria (Cutaneous) Testing Algorithm
Useful For: Establishing a biochemical diagnosis of erythropoietic protoporphyria Differential
diagnosis of chronic intoxication from exposure to a variety of causes including heavy metals and
chemicals Differential diagnosis in some cases of iron-deficiency anemia There are 2 test options:
whole blood (PPFE/8739 Protoporphyrins, Fractionation, Whole Blood) and washed RBCs
(PPFWE/31891 Protoporphyrins, Fractionation, Washed Erythrocytes). The whole blood option is
easiest for clients but requires that the specimen arrive at Mayo Medical Laboratories within 72 hours of
draw. When this cannot be ensured, washed RBCs should be submitted.
Interpretation: Values of zinc-complexed protoporphyrin >60 mcg/dL suggest iron deficiency
anemia or may indicate chronic intoxication by heavy metals or organic chemicals. A predominance of
noncomplexed (free) protoporphyrin indicates a diagnosis of erythropoietic protoporphyria.
Reference Values:
FREE PROTOPORPHYRIN