Not so with HIV. Spread primarily through sexual contract or infected blood products, HIV turned out to be a relentless insurgent, ravaging the immune systems of most people who came in contact with it. Over time, by destroying the cells that direct the rest of the immune system (the helper T-cells or CD4 cells), HIV makes it harder and harder for an infected body to fight off certain cancers and infections. As the disease progresses, bacteria, viruses and other microbes that would rarely harm a healthy person can explode into severe, sometimes fatal, infections.

Technically, a diagnosis of HIV infection becomes an AIDS diagnosis only after blood tests show that an infected person has fewer than 200 helper T-cells per microlitre of blood. (Healthy adults usually have 1000 or more t-cells per microlitre of blood.) Without treatment, the number of CD4 cells drops over time, the patient becomes more and more immunosuppressed and develops severe infections. Many of the more than 35 million or so people worldwide now infected with HIV are so debilitated they can’t hold down a job or even do household chores. Some of them experience periods of intense, life-threatening illness followed by periods of normal functioning. But a very small number of patients with HIV show no outward evidence of infection at all, even 18 years or so after contracting the virus.

What does the future holds AIDS / HIV patients?

Protease inhibitors, a new class of anti-HIV drugs, have increased life expectancy and reduced illness episodes for many AIDS patients. Scientists are now trying to find out how long-term survivors are different and why they are protected. On other fronts, a flurry of research is focusing on creating the next generation of antiviral drugs, including ‘fusion inhibitors’ that cripple HIV’s ability to attach to and disable white blood cells. Although there are no absolute answers or solutions yet, the fervent desire to stop the rapid spread of HIV has shed much light on the secrets of the immune system – knowledge that is already helping to prolong life and promote health for all, not just those with HIV.

This immune-system disaster typically ravages the body in three main ways:
1. As a direct attack on an organ, such as the skin (which occurs in psoriasis, for example);
2. As a domino effect – for instance, when lupus causes inflammation in the kidneys that leads directly to kidney damage; and
3. As a response that starts in one spot, then spreads. The swellings of rheumatoid arthritis affects joints first but can move on to involve other tissues.

What allows the immune system to run amok in this way is quite a mystery. It seems that many factors from viruses, to certain drugs, to sunlight – may play a role. Heredity appears to be a strong influence, but, oddly when these disorders cluster in families, they can surface as different illnesses. A mother may have lupus; her daughter, juvenile diabetes; and her grandmother, rheumatoid arthritis. Although ‘auto-immune disease’ refers to more than 80 illnesses, only a few affect lots of people.

Among those that do are:
- Hashimoto’s thyroiditis
Continued attack by the immune system destroys the thyroid gland, an organ that helps control the body’s metabolism, leading to an underproduction of thyroid hormone. Luckily, the deficiency can be made up with medication.
- Graves’ disease
This is another auto-immune problem involving the thyroid, but this time, it has the opposite effect, with the gland producing too much of the thyroid hormone.
- Lupus
This disorder (the full name is systemic lupus erythematosus) can involve inflammation of the different tissues and organs, such as the joints, skin, kidneys and even the brain, in different people.
- Rheumatoid arthritis
This immune system attacks the tissue that lines and cushions the joints – most often in the knees, wrists and hands – causing scarring within the joint that eventually disables one in ten sufferers.
- Multiple sclerosis
A disorder in the which the immune system methodically destroys myelin, the coating that protects the nerve fibres of the eye, brain and spinal cord. For some reason, people who grow up in tropical climates are much less likely to suffer from this disease.

Women & Autoimmune Diseases

Scientists don’t know for certain why, but the vast majority of auto-immune diseases occur in women.
Below are the female to male ratios of autoimmune diseases:

• Hashimoto’s thyroiditis – 50:1
• Systemic lupus erythematosus – 9:1
• Antiphospholipid syndrome – 9:1
• Sjögren’s syndrome – 9:1
• Primary biliary cirrhosis – 9:1
• Autoimmune hepatitis – 8:1
• Graves’ disease – 7:1
• Rheumatoid arthritis – 4:1
• Scleroderma – 3:1
• Juvenile diabetes – 2:1
• Multiple scleroris – 2:1