HIV-1 Antigen and HIV-1 / HIV-2 Antibody (Human Immunodeficiency Virus) with Reflex to HIV-1/HIV-2 Antibody Differentiation

Brief Description

Specimens will be screened by using a CMIA test for the qualitative detection of HIV-1 p24 antigen, and IgM and IgG antibodies to HIV-1 and/or HIV-2.
Any repeatedly reactive CMIA specimen will be tested with the Geenius assay that differentiates antibodies to Human Immunodeficiency Virus Types 1 and 2 (HIV-1/HIV-2).
If the Geenius Interpretation is Negative, HIV-1 Indeterminate, HIV-2 Indeterminate, or HIV Indeterminate, the specimen will be sent out for an HIV nucleic acid test (NAT) if specimen requirements are met.
This multi-test algorithm is recommended by the Centers for Disease Control and Prevention (CDC) and has been adopted by the Clinical Laboratory Standards Institute (CLSI) for the diagnosis of HIV.
This test is not intended for use in screening blood or plasma donors. This test has not been FDA approved for children less than 2 years of age or for cadaveric specimens.

Laboratory Unit



Chemiluminescent Microparticle Immunoassay (CMIA) / Immunochromatographic

Specimen Collection

One 6 mL red top vacutainer tube or EDTA, heparin, serum separator (SST)


6 mL of whole blood or 1.5 mL of serum or plasma at 2-8° C
Store specimens at refrigerator temperature (2-8° C) prior to shipment.
Specimens should be sent daily or next working day.
Transport in MSPHL shipping containers at room temperature.

Acceptable Specimen Type(s)

Serum, plasma

Test Request Form(s)

Possible Results

CMIA:  Reactive, Non-Reactive, Unsatisfactory
Geenius Interpretation: HIV-1 Positive, Negative, HIV-1 Indeterminate, HIV Positive (Untypable), HIV-2 Positive, HIV-2 Indeterminate, HIV Indeterminate, HIV-2 Positive with HIV-1 cross reactivity, Unsatisfactory

Unacceptable Conditions

No Name on Specimen
Name on Specimen Does Not Match Name on Request Form
Quantity Not Sufficient
Grossly Hemolyzed
In Transit for More Than 10 Days

Interfering Substances

Hemolysis and bacterial contamination

Result Reported

1-3 days after receipt of specimen



CPT Codes

87389 HIV-1 Ag/HIV-1 and HIV-2 Ab; if reflexed, add HIV-1 and HIV-2 Antibody Differentiation 86701 and 86702


HIV Ag/Ab Combo: 56888-1, Geenius: 80203-3 (HIV-1 Ab: 68961-2, HIV-2 Ab: 81641-3)

Additional Information

Testing alone cannot be used to diagnose AIDS, which is a clinical syndrome. The diagnosis of AIDS must be established clinically. A nonreactive result does not exclude the possibility of exposure to or infection with HIV-1 and/or HIV-2. Nonreactive results may be because antigen and antibody levels are below the limit of detection of this assay.