HIV destroys our immune system, mainly one specific part of it — the T-helper Lymphocyte (a type of white blood cell; also called a CD4 or T4 cell). During the first few months after getting infected with the virus, there’s lots of activity within the immune system, but this settles down — see Acute (Primary) HIV. From then on, bit by bit, HIV destroys these CD4 cells. The body produces new ones, but the destruction occurs just a little quicker.
As a ballpark generalization, a person without HIV has about 1,000 CD4 cells per microliter of blood. Some of us only have 700, others 1,300. On the average, HIV destroys 80-100 per year (sometimes more, sometimes fewer). Everything discussed below assumes a person is not receiving HIV Treatment.
The CD4 cells hold all sorts of strange bacteria, viruses, and parasites in check. There are harmful germs we have within us since early childhood, which never because problems, because our immune system contains them. But when we’ve lost enough CD4 cells, these germs can break free, and cause terrible illnesses called Opportunistic Infections (see AIDS). This takes an average of 8 years since getting infected with HIV (maybe more, maybe less).
These 8 years are called the “Asymptomatic Period,” because most persons don’t have any symptoms. But some do. As a ballpark generalization, we gauge a patient’s risk by their CD4 count, as follows:
- >500 CD4 cells — no risk of illness (Hepatitis B & C can be more aggressive, and there are certain things that some people with HIV get which have nothing to do with CD4 counts; see below).
- 350-500 CD4 cells — still no real risk, see above.
- 200-350 CD4 cells — risks of some symptoms, and some diseases (a few of them bad) which people without HIV can also get. No real risk of AIDS-related opportunistic infections (or maybe a very rare risk)
- <200 CD4 cells — real risk of AIDS-related opportunistic infections, often curable (see AIDS)
- <50 CD4 cells — risk of incurable AIDS-related opportunistic infections (so patients die)
The types of symptoms people get during this “Asymptomatic” period before AIDS fall into 2 categories: 1) Some can happen regardless of CD4 count, and do not indicate the immune system is getting weaker; and 2) Symptoms which are not Opportunistic Conditions, but which do indicate the immune system is losing its strength. They usually occur when the CD4 count falls below 350. If we find any of these in a person without known HIV, we order the test.
1. Symptoms during HIV infection that do not mean the immune system is getting weaker:
- Lymphadenopathy (swollen glands), not just around the front of the neck or tonsils, but in the back of the neck, behind the ear, back of the head, armpits, and elbows. Syphilis & other infections can cause the same thing, but a person should certainly get an HIV test.
- Low platelet count on a CBC blood test, even if not dangerously low
- High globulins on a routine blood test
- Very low HDL-cholesterol (like under 25)
- Shingles (Herpes Zoster, not the STD Herpes)
2. Symptoms and conditions, usually <350 CD4 cells, which do indicate a weakening immune system:
- Fevers and night sweats (unexplained
- Weight loss
- Chronic diarrhea (with no other cause)
- Lots of Yeast Infections in the vagina or tip of the penis (test for HIV & also Diabetes)
- White patches on red base in the mouth (not on the tongue) — yeast infection (Thrush)
- Purple spots, like bruises, but sort of lumpy, on skin or mouth (Kaposi’s Sarcoma)
- Pneumonia or Sinusitis caused by bacteria, more than 2 times in a year
- Invasive Cervical Cancer (found on a Pap test)
- Non-Hodgkin’s Lymphoma (a serious blood cancer)
- Reactivation of TB (if you already have the germ inside you)
- Rarely, an Opportunistic Infection (AIDS)
All of the above either get better, and/or can be prevented, with HIV Treatment.
In the mid-2000’s, we used to hold off on giving treatment until the CD4 count dropped to near 350, because there wasn’t risk of getting sick before that. But now we realize that just having HIV inside you isn’t good for the body. The immune system actively tries to fight it, and the chemicals that pour out during this are bad for the heart, the kidneys, and may contribute to causing cancer. Studies suggest that simply living with untreated HIV may be as dangerous as cigarette smoking.
See our other topics Overview of HIV, Acute (Primary) HIV, AIDS, and HIV Treatment.