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Test ID: ASB Arsenic, Blood

Reporting Name

Arsenic, B

Useful For

Detection of acute or very recent arsenic exposure

 

Monitoring the effectiveness of therapy

 

This test is not useful for evaluation of chronic arsenic exposure.

Clinical Information

Arsenic (As) exists in a number of toxic and nontoxic forms. The toxic forms are the inorganic species As(5+), also denoted as As(V), the more toxic As(3+), also known as As(III), and their partially detoxified metabolites, monomethylarsine (MMA) and dimethylarsine (DMA). Detoxification occurs in the liver as As(3+) is oxidized to As(5+) and then methylated to MMA and DMA. As a result of these detoxification steps, As(3+) and As(5+) are found in the urine shortly after ingestion, whereas MMA and DMA are the species that predominate more than 24 hours after ingestion.

 

Blood concentrations of arsenic are elevated for a short time after exposure, after which arsenic rapidly disappears into tissues because if its affinity for tissue proteins. The body treats arsenic like phosphate, incorporating it wherever phosphate would be incorporated. Arsenic "disappears" into the normal body pool of phosphate and is excreted at the same rate as phosphate (excretion half-life of 12 days). The half-life of inorganic arsenic in blood is 4 to 6 hours, and the half-life of the methylated metabolites is 20 to 30 hours. Abnormal blood arsenic concentrations (>12 ng/mL) indicate significant exposure, but will only be detected immediately after exposure. Arsenic is not likely to be detected in blood specimens drawn more than 2 days after exposure because it has become integrated into nonvascular tissues. Consequently, blood is not a good specimen to screen for arsenic, although periodic blood levels can be determined to follow the effectiveness of therapy. Urine is the preferred specimen for assessment of arsenic exposure.

 

A wide range of signs and symptoms may be seen in acute arsenic poisoning including headache, nausea, vomiting, diarrhea, abdominal pain, hypotension, fever, hemolysis, seizures, and mental status changes. Symptoms of chronic poisoning, also called arseniasis, are mostly insidious and nonspecific. The gastrointestinal tract, skin, and central nervous system are usually involved. Nausea, epigastric pain, colic (abdominal pain), diarrhea, and paresthesias of the hands and feet can occur.

Interpretation

Abnormal blood arsenic concentrations (>12 ng/mL) indicate significant exposure.

 

Absorbed arsenic is rapidly distributed into tissue storage sites with a blood half-life of <6 hours. Unless a blood specimen is drawn within 2 days of exposure, arsenic is not likely to be detected in a blood specimen.

Analytic Time

1 day

Day(s) and Time(s) Performed

Monday through Saturday; 2 p.m.

Clinical Reference

1. Hall M, Chen Y, Ahsan H, et al: Blood arsenic as a biomarker of arsenic exposure: results from a prospective study. Toxicology. 2006;225 (2-3):225-233

2. Strathmann FG, Blum LM: Toxic Elements. In: Rafai N, Horwath AR., Wittwer CT, eds. Tietz Textbook of Clinical Chemistry and Molecular Diagnostics 6th ed. Elsevier, 2018;chap 42

Method Name

Inductively Coupled Plasma-Mass Spectrometry (ICP-MS)

Specimen Type

Whole blood


Advisory Information


The preferred method of screening for arsenic exposure is measurement of urinary arsenic concentration. Order either ASFR / Arsenic Fractionation, 24 hour, Urine or ASFRU / Arsenic Fractionation, Random, Urine.



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.

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

Container/Tube: Royal blue-top (EDTA) plastic trace element blood collection tube

Specimen Volume: Full tube

Collection Instructions:

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

2. Send specimen in original collection tube.

Additional Information: If ordering the trace element blood collection tube from BD, order catalog #368381.


Specimen Minimum Volume

0.3 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Whole blood Refrigerated (preferred) 28 days
  Ambient  28 days
  Frozen  28 days

Reference Values

<13 ng/mL 

Reference values apply to all ages.

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 U.S. Food and Drug Administration.

CPT Code Information

82175

LOINC Code Information

Test ID Test Order Name Order LOINC Value
ASB Arsenic, B 5583-0

 

Result ID Test Result Name Result LOINC Value
32190 Arsenic, B 5583-0
Mayo Clinic Laboratories | Neurology Catalog Additional Information:

mml-Behavioral, mml-Neuromuscular