HIV-1 RNA qualitative assay (for diagnosis) - blood plasma specimen

Collect

PREFERRED: PLASMA is the preferred specimen and Plasma Preparation Tubes (PPT clear tubes with K2 EDTA) are the preferred collection tubes. Other collection tubes containing K2 EDTA, K3 EDTA, Acid Citrate Dextrose (ACD), or sodium citrate may be used.

REMARK: SERUM is an acceptable alternative specimen.

Volume Required

4-6 ml; tube should be completely filled, if possible

Minimum Required

4-6 ml; tube should be completely filled, if possible

Transport

Room temperature

Stability

Whole blood, plasma or serum are stable at room temperature (up to 25 C) for 72 hours after draw.

Processing

Transport specimens to the Clinical Virology Laboratory as soon as possible after collection. Specimens are accepted Monday through Sunday. Whole blood, plasma or serum may be stored up to 72 hours from the time of draw at less than or equal to 25C (room temperature). Temperatures less than or equal to 30C are acceptable for 24 hours. Plasma or serum separated from the cells may be stored an additional 5 days at 2-8C (refrigerator temperature) and may be stored for longer periods of time at -70C before testing. Do not freeze the whole blood.

Unacceptable conditions

Clotted specimens, specimens collected in inappropriate blood draw tubes, and specimens that are not transported correctly.

Days Performed

Tuesday, Thursday

Reported

Same day

Reflex Testing

N/A

CPT

87535

Methodology

The Gen-Probe APTIMA HIV-1 RNA Qualitative Assay uses transcription-mediated amplification (TMA) to replicate highly conserved regions of the HIV-1 long terminal repeat (LTR) and POL genomic RNA.

Disease Information

Utility:

This is the first nucleic acid amplification test specifically approved by the Food & Drug Administration (FDA) for use as an aid in the diagnosis of HIV-1 infection, including acute or primary infection prior to or at the time of seroconversion. Indications for use of this assay include (a) screening of high-risk populations, (b) testing in the setting of known occupational health exposure, (c) testing patients with acute HIV-1 symptoms and known exposure, and (d) screening newborn babies born to infected mothers. This assay also can be used as a supplemental test for routine screening of all patients being tested for HIV-1 antibodies/antigen, and may be used to confirm HIV-1 infection in an individual whose specimen is repeatedly reactive for HIV-1 antibodies/antigen. The new test is extremely sensitive, and has detection rates of 98.5% for 30 RNA copies/ml, 82.6% for 10 copies/ml, 42.5% for 3 copies/ml, and 19.4% for 1 copy/ml. The test detects all major groups (M, N, and O) and subtypes of HIV-1, and can detect HIV-1 infection 12 days earlier than current antibody assays. NOTE: The new test should not be used in place of routine HIV antibody/antigen combo screening, but in conjunction with antibody/antigen combo assays. HIV antibody/antigen combo testing remains as the initial frontline diagnostic tool.

Interpretation

A positive test result indicates that HIV-1 RNA was detected. For a patient who is repeatedly reactive in our 4th generation antibody/antigen combo screening immunoassay and is positive in the HIV-1 RNA qualitative test, the individual is considered to have a confirmed infection with HIV-1. Presence of HIV-1 RNA in a patient who is repeatedly reactive in our 4th generation antibody/antigen combo screening immunoassay but negative or indeterminate by HIV-1 Western blot is also indicative of a confirmed acute or primary HIV-1 infection. A patient that is positive in the HIV-1 RNA qualitative assay but who has not been tested in a screening test for HIV antibodies/antigen should be further tested using a licensed test for HIV antibodies/antigen. A negative test result does not preclude the possibility of exposure to or infection with HIV-1. A specimen that is negative in the HIV-1 RNA qualitative assay and repeatedly reactive in our screening test for HIV antibodies/antigen should be tested by an HIV-1 Western blot to confirm the presence of HIV-1 antibodies. An equivocal test result indicates that the presence or absence of HIV-1 RNA in a specimen could not be verified. If clinically, indicated, a freshly collected specimen should be submitted for repeat HIV-1 RNA qualitative testing. An appropriate blood specimen may also be submitted for an HIV antibody/antigen combo screening test.

Reference Values

Negative or no HIV-1 RNA detected by molecular amplification (TMA)

Remarks

As of 15 May 2012, written informed consent for HIV testing is no longer required; documentation of verbal consent is adequate. Our hospital policies have been modified to conform with the revised Pennsylvania Act 148 (state statute that governs HIV testing) and the emphasis of the Commonwealth of Pennsylvania and Centers for Diseases Control and Prevention to provide routine HIV testing of individuals 13-65 years of age. This policy change applies to CHOP affiliated inpatient and outpatient care sites in Pennsylvania, New Jersey and Delaware. The new HIV-related policies can be found in the online Patient Care Manual. The patient or person consenting to the test must still be notified of the intent to test and be provided with HIV-related information. Two handouts are available in the Patient-Family Education Manual to provide information about HIV and HIV testing: "Understanding HIV: Testing and Prevention" and "HIV Testing is for Everyone". A competent minor, regardless of age, is permitted under Pennsylvania state law to consent to HIV testing and/or treatment services. Parental consent is not required. Otherwise, verbal consent can be obtained only from a biologic parent, an adoptive parent, legal guardian, or by a court order. Documentation in the medical record must show that verbal consent was obtained. Documentation of verbal consent for an HIV-related test can be accomplished through the Epic hospital computer system by selecting one of two certifications; either "I certify that the patient and/or personal representative have been given information about HIV testing and have verbally consented to the test" OR "I certify that HIV testing is required because of a life threatening medical condition or occupational exposure, and obtaining consent is not possible at this time".