AIDS and the early stages of HIV infection are diseases of the immune system caused by the human immunodeficiency virus or HIV-2. This virus is responsible for infecting and destroying the T-helper lymphocytes (CD4 cells). This destruction, in turn, affects the ability of the body to produce antibodies and suppresses cellular immune responses, leading to disorders and infections by many opportunistic infectious agents. The average time from HIV infection to development of full-blown AIDS is approximately 10 years. The clinical manifestations of the infection also can vary from an initially mild illness to an acute state. Those at high risk for the disease include male homosexuals, hemophiliacs, recipients of blood or blood products before 1985, and IV drug users who share needles. Heterosexual transmission of the virus is on the rise.³⁴

After the virus has been acquired, antigens are detectable in the blood serum as early as 2 weeks, and they remain for 2 to 4 months. At this time, antibodies appear. Late in the disease, antigens reappear and antibodies decrease, indicating a poor prognosis. The most common tests to screen for HIV-1 virus antibodies are the EIA, also known as the enzyme-linked immunosorbent assay (ELISA), and the immunofluorescence assay. The test is repeated if the results are positive or borderline. Repeat testing after a positive value requires confirmation by the Western immunoblot (WIB) assay, which has the ability to identify antibodies to at least nine different epitopes of HIV-1. Antigen testing in the early stages of HIV-1 infections before antibodies are detected can be undertaken to monitor clients for progression of the disease and response to therapy. It is also useful to diagnose HIV-1 infection in infants when maternal antibodies are passively transferred and diagnosis based on serologic testing is difficult.³⁵

• Negative for HIV antigen by antigen capture assay during initial infectious state and in advanced state of the disease
• Negative for HIV antibodies by antibody detection methods, EIA, and immunofluorescence assay
• Negative for confirmation test for HIV antibodies by WIB

• Negative results can occur in infected individuals because of lack of antibody formation early in the disease and in late stages because of loss of ability to produce antibodies.
• Inaccurate results can occur with the use of test kits that contain proteins if an individual has been exposed to the media used in the kits.
• Cross-reactive antibodies directed to antigenic determinants found in nonpathogenic retroviruses can result in inaccurate positive results.³⁶
• Children who become infected before birth through an infected mother can have inaccurate negative results.
• Corticosteroids can affect lymphocyte subset test results.
• Protease inhibitors can inhibit replication of infected cells and cell-to-cell spread of HIV.

• Detection of the core p24 protein and antibodies to the identified protein in the diagnosis and staging or progression of infections in AIDS
• Confirmation of positive test results obtained by EIA to ensure accurate results
• Determination of the extent of CD4 (T-helper lymphocytes) cell decreases in relation to normal or increased levels of CD8 (T-suppressor) cells to predict immunodeficiency state
• Prediction of exacerbation of the disease by increased protein ₂-microglobulin, indicating destruction of lymphocytes and macrophages
• Assistance in the diagnosis of AIDS in the presence of opportunistic infections determined by culture and microorganism identification
• Screening of those in high-risk groups for the development of AIDS
• Screening of blood donors by blood banks before obtaining blood donations
• Screening of blood before using for transfusion or preparation of blood products

Nursing Care Before the Procedure

Client preparation is the same as for any study involving the collection of a peripheral blood sample (see Appendix I).

• Obtain a history regarding possible contact with the virus such as sexual practices, drug abuse with needle sharing, transfusion with contaminated blood products, or presence of pregnancy (virus could be transmitted to the infant). Inform the client of confidentiality and legal requirements regarding the test performance and test results.

A venipuncture is performed and the sample collected in a red-topped (antigen or antibody) or lavender-topped (lymphocyte or microglobulin) tube, depending on the tests to be performed. Appropriate apparel (gloves and mask) and precautions for blood-borne pathogens are carried out when obtaining and caring for the blood samples (see Appendix III).

Nursing Care After the Procedure

Care and assessment after the procedure are the same as for any study involving the collection of a peripheral blood sample.

• Abnormal values: Note and report positive test results. Inform client of the most current information regarding medications, economic and social assistance, and possible psychological counseling services. Instruct client in adequate nutritional and fluid intake. Provide a sensitive, nonjudgmental, and caring environment for the client.
• Disease transmission: Instruct client in precautions to take during sexual activity; advise to avoid sharing needles during drug use and to avoid donating blood. Provide care using standard precautions and observing transmission-based isolation procedures for blood-borne pathogens.
• Medicolegal aspects: Observe regulations for confidentiality in reporting test results, such as use of computer or telephone. Maintain confidentiality of records containing test results. Carry out state regulation regarding the reporting of positive results. Provide a form for physician to sign regarding any risks associated with testing and obtain a signed informed permission request before the test. Contact Centers for Disease Control and Prevention (CDC) for the latest guidelines on reporting HIV status and appropriate follow-up and counseling.