Hope this helps....

I could find no connection between HIV and autoimmune disease...since they are the opposite of each other. For HIV testing.....
[There are several types of tests associated with HIV disease. Some test for antibodies that the body makes in response to the virus, some test for levels of a protein (called p24) found in the virus, some test for the actual number of copies of the virus per milliliter of blood (called viral load testing), some test for levels of immune cells called CD4 cells that are attacked by HIV, and some test for whether patients are resistant to anti-HIV drugs. ]
About Autoimmune disorders:
Autoimmune disorders fall into two general types: those that damage many organs (systemic autoimmune diseases), and those where only a single organ or tissue is directly damaged by the autoimmune process (localized). Some of the most common types of autoimmune disorders include:
Systemic Autoimmune Diseases Localized Autoimmune Diseases
Rheumatoid arthritis (joints; less commonly lung, skin)
Type 1 Diabetes Mellitus (pancreas islets)
Lupus [Systemic Lupus Erythematosus] (skin, joints, kidneys, heart, brain, red blood cells, other)
Hashimoto’s thyroiditis, Graves’ disease (thyroid)
Scleroderma (skin, intestine, less commonly lung)
Celiac disease, Crohn's disease, Ulcerative colitis (GI tract)
Sjogren’s syndrome (salivary glands, tear glands, joints)
Multiple sclerosis*, Guillain-Barre syndrome (brain)
Goodpasture’s syndrome (lungs, kidneys)
Addison’s disease (adrenal)
Wegener’s granulomatosis (sinuses, lungs, kidneys)
Primary biliary sclerosis, Sclerosing cholangitis, Autoimmune hepatitis (liver)
95%-98% of patients with SLE will have a positive ANA test, but the majority of people with a positive ANA test do not have SLE. A positive ANA test can be found in many conditions, including Sjogren's Syndrome, scleroderma, rheumatoid arthritis, & mixed connective tissue disease. Many normal healthy people will also have a positive ANA test. Therefore a positive ANA test, on it's own, does not mean that person has lupus.
Because of this, the physician has to look very carefully at the titer (number) & pattern of the ANA test. The titer shows how many times the technician had to mix fluid from the patient's blood to get a sample free of ANAs. Thus a titer of 1:640 shows a greater concentration of ANA than 1:320 or 1:160, since it took 640 dilutions of the plasma before ANA was no longer detected. The apparent great difference between various titers can be misleading. Since each dilution involves doubling the amount of test fluid, it is not surprising that titers increase rapidly. In fact, the difference between titers of 1:160 & 1:320 is only a single dilution. And it doesn't necessarily represent a major difference in disease activity.
ANA titers go up & down during the course of the disease, & may or may not reflect disease activity. Therefore it is not always possible to tell from the titer how severe a person's lupus is.