Human Immunodeficiency Virus (HIV) is a lentivirus which is the subgroup of retroviruses. It causes AIDS (Acquired Immune Deficiency Syndrome), disease which is the crash of immune system. HIV depresses the CD4+ T Lympocytes which are responsible for immune system activity and in this way, the body becomes susceptible to other virutic infections which the body can defend itself under normal immune condutions. These are; tuberclosis, diarrhea, meningitis, pneumonia and in some cases, cancer. Total HIV Antibodies represent all types of antibodies (IG M ,Ig G) and additionally antibodies to p24 antigens of the virus. HIV I+II test, also known as Elisa test, should also be performed on the 90 th day, after contamination, in order to leave no doubts about the antibodies detectibility.
If there is a doubt of contamination, early diagnose is valuable. Therefore, there are some early diagnostic parameters.These are; HIV RNA PCR test and p24 Antigens. HIV RNA PCR test is positive within 9 days after contamination. In fact, this is the DNA of the active virus. In 28 days, the sensitivity of the test becomes %98-100. It is the Polymerase Chain Reaction genetic test, based on the production of the copies of HIV Virus RNA.
Another early test is p 24 Antigen test which is a spesific protein found in the virus itself. The p 24 antigen reaches its peak level in 2-6 weeks after the suspected contamination. After the antibodies start to fight with the virus, p 24 declines gradually.
Interpretation:Positive Anti HIV result means that the patient has been infected with the virus at least 4-6 weeks ago because there should be adequate time for the immune system to build antibodies. This test measures the antibodies produced in response to HIV virus. Positive p24 test means that the person has had the acute infection approximately 2-6 weeks and is trying to fight the virus with increasing antibody synthesis. Positive HIV RNA test is the definite actively contamination approximately in 9-10 days. Posiible contamination day may be discussed with the patient to decide about which test or tests should be performed for diagnosis.
Sample: Arm vein plasma-EDTA
Working day: Thursday
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