AIDS and HIV Infection

views updated May 29 2018

AIDS and HIV Infection

What Are AIDS and HIV?

How Common Is HIV Infection?

How Is HIV/AIDS Spread?

What Are the Signs and Symptoms of HIV/AIDS?

How Is HIV/AIDS Diagnosed?

How Is HIV/AIDS Treated?

Can HIV/AIDS Cause Other Medical Complications?

How Can HIV/AIDS Be Prevented?

Resources

HIV, or human immunodeficiency (HYOO-mun ih-myoo-no-dih-FIH-shen-see) virus, is a virus that can weaken the body’s immune system*. Infection with HIV causes a life-threatening illness called AIDS, or acquired immunodeficiency syndrome.

*immune system: is the system of the body composed of specialized cells and the substances they produce that helps protect the body against disease-causing germs.

KEYWORDS

for searching the Internet and other reference sources

Highly active antiretroviral therapy (HAART)

Immunodeficiency

Opportunistic infections

Protease inhibitors

Retroviruses

Sexually transmitted diseases

T-lymphocytes

What Are AIDS and HIV?

AIDS is the disease caused by human immunodeficiency virus type 1, or HIV-1 (usually referred to as HIV). HIV belongs to the retrovirus family, a group of viruses that have the ability to use cells’ machinery to replicate (make more copies of the infecting virus).

HIV attacks the immune system by damaging or killing a specific type of white blood cell in the body called a T-lymphocyte (LIM-fo-site), also called a CD4+ or T-helper cell. T-lymphocytes help the immune system perform its important task of fighting disease in the body caused by invading germs. As a result of HIV infection, the immune system becomes weakened and the body has trouble battling certain infections caused by bacteria, viruses, parasites, and fungi. Many of these infections are highly unusual in people with healthy immune systems. They are called opportunistic infections because they take advantage of a weakened immune system. People with HIV disease not only are more likely to contract these infections, they are more likely to have them repeatedly and to become much more sick from them.

Infection with HIV takes about 10 years to develop into full-blown AIDS. During most of this period, people usually look and feel healthy

The HIV virus attacks T-helper cells, or CD4+ cells, by fitting itself into the cell like a key in a lock. Once it has invaded, it can use its own RNA as a template to make copies of itself, multiplying and traveling through the body. This process destroys the body’s own T cells over time; as the T-cell count falls, the body’s resistance to germs and disease declines.

and are not aware that they are infected unless they are tested for the virus. Currently, experts think that, untreated, people with HIV infection eventually will develop AIDS unless they die first of other causes. Medications for HIV infection improved greatly in the 1990s, and the life expectancy of people receiving proper treatment has been extended dramatically. However, none of these medicines actually cure the infection.

Worldwide, about one-third of people with HIV/AIDS are between 15 and 24 years of age. Teens and young adults are at particular risk because they are more likely to have unprotected sex.

AIDS was first described in the United States in 1981, after many gay men in San Francisco and New York City became ill from an unknown infectious cause. In 1985, it became clear that a retrovirus causes AIDS.

How Common Is HIV Infection?

In some areas of the world, such as in sub-Saharan Africa, rates of HIV infection are extremely high and continue to rise rapidly. Worldwide, it is estimated that 42 million people are living with HIV/AIDS. In 2002 alone, 5 million people became infected with HIV, and more than 3 million died from AIDS. Many infected people live in impoverished areas where medicines and other treatments are not available or affordable.

In the United States, HIV infection is less common. According to the U.S. Centers for Disease Control and Prevention (CDC), by the end of 2001 a total of about 816,000 cases of AIDS had been reported and about 468,000 deaths had been attributed to AIDS since the disease was first recognized. More than 9,000 children in the United States under the age of 13 are living with AIDS. The infection is spreading most rapidly among people of African ancestry and people of Latino ancestry, especially among young men. As with other sexually transmitted diseases (STDs), teens and young adults are at higher risk for contracting HIV infection because they are more likely to have unprotected sex. Approximately one-third of people worldwide with HIV or AIDS are 15 to 24 years old.

Since 1987 the AIDS Memorial Quilt (shown here on display in Washington, D.C.) has underscored the devastating impact of the disease. Each of the more than 44,000 panels memorializes the life of someone who has died of AIDS. Paul Margolies

How Is HIV/AIDS Spread?

HIV/AIDS is contagious from person to person. People can spread the virus before they have developed any symptoms and are unaware they are infected. The HIV virus spreads in certain body fluids, including blood, semen*, breast milk, vaginal* fluid, and any other body fluid that contains blood. HIV can spread in the following ways:

*semen: (SEE-men) is the sperm-containing whitish fluid produced by the male reproductive tract.

*vaginal: (VAH-jih-nul) refers to the canal in a woman that leads from the uterus to the outside of the body.

through vaginal, anal, or oral sexual intercourse
by sharing needles to inject intravenous* (IV) drugs

*intravenous: (in-tra-VEE-nus) means within or through a vein. For example, medications, fluid, or other substances can be given through a needle or soft tube inserted through the skin’s surface directly into a vein.

from mother to child in the womb
during childbirth or breast-feeding
from any blood-to-blood contact with someone who is infected, such as, in very rare cases, contact with an open wound (though the virus cannot be transmitted unless the skin of both people is broken).

Because it can be difficult to see small breaks in the skin such as hangnails, doctors advise caution when coming into contact with any cut or wound on someone infected with HIV. Medical personnel are at risk of contracting HIV infection through accidental injuries with medical instruments (especially needles and scalpels) that have been contaminated with the blood of an HIV-infected patient.

The Origin of Aids

Evidence suggests that AIDS likely originated in Africa from a virus called simian immunodeficiency virus (SIV) found in monkeys. People probably became infected with SIV from a particular type of chimpanzee when they hunted the chimpanzees for food. Once the virus was in humans, it may have mutated (changed) into the virus known as HIV.

Sharing living space or items such as eating utensils or clothes does not transmit the virus. Neither does casual contact—doing things like hugging or shaking hands—so there is no need to avoid this type of contact with someone who has HIV. Blood donations and blood products in the United States have been screened for HIV since 1985, and today the blood supply is considered safe. The risk of becoming infected through blood transfusions* is extremely low.

*transfusions: (trans-FYOO-zhunz) are procedures in which blood or certain parts of blood, such as specific cells, are given to a person who needs them because of illness or blood loss.

What Are the Signs and Symptoms of HIV/AIDS?

Before a person has developed signs of AIDS, it is impossible to tell whether someone is infected with HIV by just looking at that person. People usually develop an illness with symptoms like those of the flu a few weeks after becoming infected with the virus. They may have a fever, a sore throat, muscle aches, and, sometimes, a measles-like rash. This illness usually goes away after a couple of weeks, and other symptoms may not appear for 5 to 15 years. The incubation (ing-kyoo-BAY-shun) period, or amount of time after infection before symptoms appear, varies from person to person.

In 1984, at the onset of the AIDS epidemic, Ryan White became infected with the HIV virus through a blood transfusion. His spirited fight to educate the public about the disease and to end prejudice against people with AIDS ended with his death in 1990 at the age of eighteen. Corbis Corporation (New York)

When symptoms do appear, they might include dry cough, sweating excessively at night, rapid weight loss, recurring fever, pneumonia, white spots or patches on the tongue or throat, headache, persistent diarrhea (dye-uh-REE-uh), memory loss, depression, extreme tiredness, skin rashes, and swollen lymph nodes*.

*lymph: (LIMF) nodes are small, bean-shaped masses of tissue that contain immune system cells that fight harmful microorganisms. Lymph nodes may swell during infections.

How Is HIV/AIDS Diagnosed?

In order to diagnose HIV infection, doctors perform a blood test to look for antibodies* to the virus. This test may not show signs of infection until several months after infection occurs. Other tests can detect the presence of the virus in the blood directly. The most common of these uses a technique called the polymerase (pah-LIM-er-ace) chain reaction (PCR). Special cultures* of the blood for HIV or a measurement of p24 antigen (AN-tih-jen), a part of the virus’s coat, are available but are used less frequently.

*antibodies: (AN-tih-bah-deez) are protein molecules produced by the body’s immune system to help fight specific infections caused by microorganisms, such as bacteria and viruses.

*cultures: (KUL-churz) are tests in which a sample of fluid or tissue from the body is placed in a dish containing material that supports the growth of certain organisms. Typically, within a few days the organisms will grow and can be identified.

A diagnosis of AIDS is made when a person who is infected with HIV develops certain infections or conditions associated with the disease that indicate a weakening of the immune system. AIDS is also diagnosed when the number of CD4+ T-cells in the body drops below a certain level. The level or “count” of these cells can be measured by taking a blood sample.

About one in four infants born to mothers infected with HIV will be infected with the virus if the mother does not receive treatment during her pregnancy, and the baby after birth, to prevent spread of HIV to the infant. Sometimes infants who are not infected test positive for HIV antibodies in their blood for more than a year because antibodies were passed to the baby through the placenta* from the mother. Other tests must be done to help determine whether an infant is truly infected.

*placenta: (pluh-SEN-ta) is an organ that provides nutrients and oxygen to a developing baby; it is located within the womb during pregnancy.

How Is HIV/AIDS Treated?

Receiving treatment as early as possible, before the start of symptoms, increases a person’s chances of staying healthier and living longer with HIV infection. Advances in treatment have greatly improved the quality of life, and prolonged life, for many people living with HIV and AIDS. Since the 1980s, various types of medications have been developed to treat AIDS. All of these drugs work by interfering with the replication cycle of HIV; they block the action of certain enzymes* that the virus needs in order to make copies of itself. Taking these medicines slows the spread of HIV in a person’s body, delaying the onset of AIDS. The class of drugs called protease (PRO-tee-aze) inhibitors (the enzyme that the drug blocks is known as a protease) has proven to be especially effective. These drugs and others are most often used in combinations of three to five medications in a treatment known as highly active anti-retroviral (an-tie-REH-tro-vy-rul) therapy (HAART). Other medicines also are used to treat or prevent the opportunistic infections associated with HIV infection. The amount of HIV in the body, called the viral load, is followed with regular blood tests to see how well treatment is working. CD4+ (T-helper) cell counts are followed as well. Over time, the virus can develop resistance to the drugs used to fight it and treatment may have to be changed, so research and development of new medicines is essential.

*enzymes: (EN-zimes) are proteins that help speed up a chemical reaction in a cell or organism.

Taking all medications exactly as they are prescribed is crucial because it can help keep resistance to the medicines from developing. Maintaining general good health, getting enough rest, eating a nutritious diet, not smoking or taking drugs, and visiting the doctor for regular checkups are also important parts of treatment.

Currently there is no cure for HIV and AIDS, so once someone becomes infected that person is infected for life. Experts believe that people with AIDS eventually will die from it, unless death from another cause occurs sooner.

Can HIV/AIDS Cause Other Medical Complications?

Complications include AIDS-related opportunistic infections; invasive bacterial infection; certain cancers such as non-Hodgkin’s lymphoma, Kaposi’s (kuh-POE-zees) sarcoma, and cervical* cancer; pneumonia; and AIDS dementia (dih-MEN-sha), in which there is impairment of thinking, memory, and concentration. HIV-infected people who use IV drugs are at increased risk for hepatitis* C infection, which can lead to severe liver damage and death. People with AIDS also are more likely to develop more severe symptoms and complications from other infections such as syphilis* and tuberculosis*.

*cervical: refers to the cervix (SIRviks), the lower, narrow end of the uterus that opens into the vagina.

*hepatitis: (heh-puh-TIE-tis) is an inflammation of the liver. Hepatitis can be caused by viruses, bacteria, and a number of other noninfectious medical conditions.

*syphilis: (SIH-fih-lis) is a sexually transmitted disease that, if untreated, can lead to serious lifelong problems throughout the body, including blindness and paralysis.

*tuberculosis: (too-ber-kyoo-LOsis) is a bacterial infection that primarily attacks the lungs but can spread to other parts of the body.

How Can HIV/AIDS Be Prevented?

Researchers are working to develop a vaccine* for AIDS. Until one is available, the best means of prevention is avoiding contact with the bodily fluids of someone who is infected. This means:

*vaccine: (vak-SEEN) is a preparation of killed or weakened germs, or a part of a germ or product it produces, given to prevent or lessen the severity of the disease that can result if a person is exposed to the germ itself. Use of vaccines for this purpose is called immunization.

avoiding sexual contact; this is the only certain way of preventing HIV infection from heterosexual or homosexual sexual contact
practicing safer sex (using a latex condom properly every time for vaginal, anal, or oral sex), which reduces but does not eliminate the risk of HIV infection; other forms of birth control such as birth control pills offer no protection against the HIV virus
avoiding IV drug use and never sharing needles for drugs, steroids, medications, tattooing, or body piercing.

For pregnant women infected with HIV, taking antiretroviral drugs during pregnancy and delivering the infant by cesarean section can greatly reduce the risk of a woman passing the infection to her baby. When

Understanding Opportunistic Infections

The opportunistic infections associated with HIV disease can affect every system in the body, such as:

Pneumocystis carinii (nu-mo-SIS-tis kah-RIH-nee-eye) pneumonia (PCP): pneumonia caused by an organism that has both parasite and fungus properties. It leads to fever, cough, and trouble breathing and can spread to the liver, spleen, and bone marrow. Untreated, the infection causes death.
Cryptosporidiosis (krip-toh-spo-rid-e-O-sis) and isosporiasis (eye-so-spuh-RYE-uh-sis): intestinal infections caused by parasites that can cause diarrhea, fever, and stomach cramps.
Cytomegalovirus (sye-tuh-meh-guh-lo-VY-rus): member of the herpesvirus family. Can cause severe infections in people with weakened immune systems. In people with HIV, it can cause an eye infection that may lead to blindness.
Histoplasmosis (his-toh-plaz-MO-sis): a fungal infection that usually begins in the lungs and causes symptoms such as fever and cough. In people with HIV infection, it can spread throughout the body and lead to problems such as nausea (NAW-zee-uh) and vomiting, joint pain, rash, and sores on the skin.
Cryptococcal meningitis (krip-toh-KAH-kul mehnin-JY-tis): an infection of the membranes lining the brain and spinal cord caused by a fungus-like organism found in soil. It can cause fever, vomiting, and hallucinations, and can eventually lead to coma or death.
Cerebral toxoplasmosis (suh-REE-brul tox-oplaz-MO-sis): an infection caused by an organism that affects the brain, heart, lungs, and other vital organs. It can cause headaches, blurred vision, seizures, and brain damage in people with HIV infection.
Disseminated mycobacterium avium (my-ko-bak-TEER-e-um A-vee-um) complex (MAC): an infection caused by bacteria found in food, water, and soil. Though these germs usually do not make people sick, in those with weakened immune systems they can cause lung disease, fever, night sweats, weight loss, and diarrhea.

treatment is given to both mother and infant, the risk of HIV transmission drops by about 75 percent. Doctors also advise that HIV-infected mothers feed their infants formula to prevent passing the virus through breast milk.

See also

Hepatitis, Infectious

Immune Deficiencies

Pneumonia

Sexually Transmitted Diseases

Syphilis

Tuberculosis

Resources

Organizations

American Foundation for AIDS Research, 120 Wall Street, 13th Floor, New York, NY 10005. The American Foundation for AIDS Research is a nonprofit organization dedicated to AIDS research, prevention, and education.

Telephone 800-392-6327 http://www.amfar.org

U.S. Centers for Disease Control and Prevention (CDC), 1600 Clifton Road, Atlanta, GA 30333. The CDC is the U.S. government authority for information about infectious and other diseases. It provides information about HIV and AIDS at its website. It also offers the National AIDS Hotline, which provides confidential information and referrals 24 hours a day.

Telephone 800-342-2437 http://www.cdc.gov

Websites

HIVInSite, from the University of California, San Francisco, offers in-depth information about HIV disease, including http://whatudo.org, a site written just for adolescents in easy-to-understand language. http://hivinsite.ucsf.edu/InSite

KidsHealth.org. KidsHealth is a website created by the medical experts of the Nemours Foundation and is devoted to issues of children’s health. It contains articles on a variety of health topics, including HIV and AIDS. http://www.KidsHealth.org

Complete Human Diseases and Conditions

AIDS-Related Cancers

views updated Jun 11 2018

AIDS-related cancers

Definition

The AIDS-related cancers are a group of cancers that occur more frequently in persons with human immunodeficiency virus (HIV) infection than in the general population. The most common form of AIDS-related cancer, Kaposi's sarcoma (KS), was one of the first indications of the AIDS epidemic in the early 1980s. While the number of new cases of KS has been declining in recent years, the number of AIDS-related lymphomas has been increasing at a rate of 2% to 3% each year.

Description

In order to understand the causes and treatment of AIDS-related cancers, it is useful to begin with a basic description of HIV infection. AIDS, or acquired immunodeficiency syndrome, is a disease of the immune system that is caused by HIV. HIV is a retrovirus, a single-stranded virus containing ribonucleic acid (RNA) and an enzyme called reverse transcriptase. This enzyme enables the retrovirus to make its genetic material part of the DNA in the cells that it invades. HIV selectively infects and destroys certain subtypes of white blood cells called CD4 cells, which are an important part of the body's immune system. As an infected person's number of CD4 cells drops, he or she is at risk of developing opportunistic infections, disorders of the nervous system, or an AIDS-related cancer. HIV is transmitted through blood or blood products that enter the bloodstream— most commonly through sexual contact or contaminated hypodermic needles.

Kaposi's sarcoma

Kaposi's sarcoma is the most common type of cancer related to HIV infection. About 20% of patients diagnosed with AIDS will eventually develop KS. There are two other major subtypes of KS—so-called classic KS and African KS—with different causes that are not yet well understood. AIDS-related KS (also called epidemic KS) is characterized by purplish or brownish lesions (areas of diseased or injured tissue) on the skin, in the mouth, or in the internal organs. The lesions may take the form of small patches or lumps (nodular lesions), large patches that grow downward under the skin (infiltrating lesions), or lumpy swellings in the lymph nodes. Unlike other cancers that typically develop in one organ or area of the body, KS often appears simultaneously in many different parts of the body. It may be the first indication that the patient has AIDS.

Non-Hodgkin's lymphoma

Lymphomas are cancers of the immune system that develop when white blood cells called lymphocytes begin to grow and multiply abnormally. The increased numbers of lymphocytes cause the lymph nodes, the organs that produce these white blood cells, to swell and form large lumps that can be felt. Lymphomas are divided into two large categories: those that are related to Hodgkin's disease (HD), and non-Hodgkin's lymphoma (NHL). HD can be differentiated from NHL by the presence of Reed-Sternberg cells in the lymphatic tissue; these cells are not found in any other type of cancer.

Non-Hodgkin's lymphoma, or NHL, occurs more often than Hodgkin's disease; about 50, 000 new cases are diagnosed annually in the United States. They may involve the spleen, liver, bone marrow, or digestive tract as well as the lymph nodes. Three important types of NHL are related to AIDS:

Primary central nervous system lymphomas (PCNSL). This type accounts for about 20% of NHL cancers found in AIDS patients, but only 1% to 2% of NHL cancers in patients not infected by HIV. Lymphomas of this type start in the brain or the spinal cord. Their symptoms include headaches, paralysis, seizures, and changes in the patient's mental condition. Patients diagnosed with PCNSL are more likely to suffer from advanced HIV infection than patients with other types of NHL.
Systemic lymphomas. These are also called peripheral lymphomas. They begin in the lymph nodes or other parts of the lymphatic system and may spread throughout the body. Burkitt's lymphoma (BL) is a type of systemic lymphoma that is one thousand times more common in AIDS patients than in the general population.
Primary effusion lymphomas, also called body cavity-based lymphomas (BCBL). This type of NHL is relatively rare, but seems to be related to infection by human herpesvirus 8 (HHV-8) in addition to HIV.

HIV-associated Hodgkin's disease

The symptoms of Hodgkin's disease include painless swelling of the lymph nodes of the neck, groin, and armpits; itching ; night sweats ; weight loss ; and fever . While one study has indicated that HIV-positive gay men have a higher risk of developing Hodgkin's disease as well as non-Hodgkins lymphomas, the Centers for Disease Control and Prevention (CDC) has not defined Hodgkin's disease as an AIDS-related cancer as of early 2001. Hodgkin's disease appears to occur more frequently in HIV-positive intravenous drug users, however, than in other persons with HIV infection.

Cervical and anal cancers

In women, cancer of the cervix (the lower end of the uterus or womb) is more likely to occur in HIV-infected individuals than in the general female population. About 60% of women with HIV infection are found to have some kind of abnormal tissue growth or cell formation in the cervix when a Pap test is performed. The human papilloma virus (HPV) is thought to be a co-factor in the development of cervical cancers. Papilloma viruses are a group of tumor-causing viruses that also cause genital warts. Cervical cancers develop more rapidly in HIV-positive than in HIV-negative women, are harder to cure, and are more likely to recur.

Cancers of the anus represent less than 1% to 2% of cancers of the large bowel. There are about 10, 000 cases of anal cancer annually in the United States. The high rates of occurrence of this type of cancer in gay men may be related more closely to the presence of HPV and to the practice of anal intercourse than to HIV infection by itself.

Other AIDS-associated cancers

Other cancers linked to HIV infection include testicular cancer , cancers of the mouth, and a type of cancer of the bone marrow called multiple myeloma . Some other cancers, including breast cancer , lung cancer, andmelanoma (a type of skin cancer), are thought to occur more frequently among people with AIDS even though they are not identified as AIDS-associated cancers in the strict sense.

Demographics

The demographic distribution of AIDS-related cancers varies somewhat depending on the type of cancer. Epidemic KS is about 10 times more common among gay men than among members of other groups at risk for AIDS (hemophiliacs, intravenous drug users, etc.); it affects men eight times as frequently as women. AIDS-related Hodgkin's disease occurs more frequently among intravenous drug users. By contrast, AIDS-related lymphomas occur with equal frequency in members of all risk groups—including the children of persons with HIV infection.

Causes

The most common types of AIDS-related cancers have been linked to oncogenic (tumor-causing) viruses:

Human herpesvirus 8 (HHV-8) is associated with KS and some of the less common types of AIDS-related lymphomas (ie. cancers of the lymphatic system).
Epstein-Barr virus (EBV) is associated with the more common types of AIDS-related lymphomas, particularly PCNSL and Burkitt's lymphoma.
Human papillomavirus (HPV) is associated with anal cancer and with cervical cancer in women.

Oncogenic viruses cause cancer by changing the genetic material inside tissue cells. When this genetic material is changed, the cells begin to grow and multiply uncontrollably. The abnormal tissue formed by this uncontrolled growth is called a tumor. A healthy human immune system has a greater ability to protect the body against oncogenic viruses and to stop or slow down tumor formation. Since the retrovirus that causes AIDS weakens the immune system, persons with AIDS are at greater risk of developing cancers caused by oncogenic viruses.

Some types of AIDS-related cancers, such as Burkitt's lymphoma, have been linked to changes in human chromosomes (translocations). In a translocation, a gene or group of genes moves from one chromosome to another. Burkitt's lymphoma is associated with exchanges of genetic material between chromosomes 8 and 14 or between chromosomes 2 and 22.

Special concerns

An important special concern for patients with AIDS-related cancers is the difficulty of combining cancer treatment—especially chemotherapy—with treatment for HIV infection. Since 1996, the standard treatment for AIDS is highly active antiretroviral therapy (HAART). HAART is a combination drug therapy involving three or four different medications. Because of the powerful side effects of these drugs, patients with AIDS-related cancers are usually put on low-dose chemotherapy for the cancer. The chemotherapy, however, increases the patient's risk of developing an AIDS-related infection, such as thrush or Pneumocystis carinii pneumonia (PCP).

Another special concern for patients with AIDS-related cancers is fear of rejection by friends and loved ones. Although the moral stigma attached to HIV infection is not as strong as it was at the beginning of the epidemic, some patients may still fear condemnation by others. Most hospitals have chaplains or spiritual counselors who can help patients with these concerns or put them in touch with someone from their own spiritual tradition.

Treatments

The different types of AIDS-related cancers have different treatment considerations.

Kaposi's sarcoma

KS differs from other solid tumors in that it lacks a stage or site of origin in which it can be cured. In addition, there is no relationship between the stage of KS and its response to treatment. Many doctors treat early KS with chemotherapy injections or treat localized lesions with radiation therapy rather than give the patient systemic chemotherapy. In 1999, the FDA approved alitretinoin (Panretin) gel as a topical treatment for KS. When systemic chemotherapy is used, the standard regimens are a combination of vinblastine (Velban) and vincristine (Oncovin) on a weekly schedule, or a combination of doxorubicin , bleomycin , and vincristine given every week. Surgery is not often used in the treatment of KS.

Non-Hodgkin's lymphoma

Patients with early, slow-growing forms of NHL are usually treated with radiation. The later stages of slow-growing non-Hodgkin's lymphomas may be treated with chemotherapy (single-agent or combination), or with a combination of radiation and chemotherapy. Common treatments for more aggressive AIDS-related lymphomas are the combination chemotherapy regimens known as CHOP (cyclophosphamide , doxorubicin, vincristine, and prednisone) or m-BACOD (intermediatedose methotrexate , bleomycin, doxorubicin, cyclophosphamide, vincristine, and dexamethasone ). In general, AIDS-related lymphomas are more aggressive than non-HIV-related lymphomas and do not respond as well to chemotherapy. PCNSL is usually treated with radiation therapy alone because most chemotherapy drugs cannot cross the blood-brain barrier and enter the central nervous system.

Newer forms of treatment for non-Hodgkin's lymphomas include bone marrow and stem cell transplants and immunotherapy with the use of monoclonal antibodies (MABs). MABs are antibodies produced by cloned mouse cells grown in a laboratory. They target cancer cells and bind to them, alerting cells of the immune system to destroy the abnormal cells. MABs are sometimes given together with chemotherapy.

HIV-associated Hodgkin's disease

HIV-associated Hodgkin's disease is usually treated with chemotherapy but does not respond as well to treatment as non-HIV-related Hodgkin's disease. Patients being treated with antiretroviral therapy may need to have it modified during a course of chemotherapy for Hodgkin's disease.

Cervical and anal cancers

Cervical and anal cancers are treated in the early stages with a combination of surgery and radiation. Larger or later-stage tumors are treated with chemotherapy (mitomycin or cisplatin and fluorouracil ) in addition to surgery and radiation treatment.

Alternative and complementary therapies

In the early years of the AIDS epidemic, a variety of alternative approaches were used to treat the internal forms of KS as well as the external skin lesions: homeopathic preparations of periwinkle, poke root (phytolacca), and mistletoe; a mixture of selenium, aloe vera gel, and silica; Chinese patent medicines; periodic three-to seven-day grape fasts as part of an overall vegetarian diet; and castor oil packs.

The only alternative treatment for KS that has been evaluated by the National Institutes of Health (NIH) is shark cartilage. Shark cartilage products are widely available in the United States as over-the-counter (OTC) preparations. The use of shark cartilage to treat KS derives from a popular belief that sharks and other cartilaginous fish (skates and rays) do not get cancer. This therapy, however, has not been proven to be effective.

Other alternative treatments for AIDS-related KS include:

Naturopathic remedies. High doses of vitamin C, zinc, echinacea, or goldenseal to improve immune function; or preparations of astragalis, osha root, or licorice to suppress the HIV virus.
Homeopathic remedies. These include a homeopathic preparation of cyclosporine and another made from a dilution of killed typhoid virus.
Ozone therapy.

With regard to other categories of AIDS-related cancers, there have been reports of using hydrazine sulfate or laetrile to treat AIDS-related lymphomas. Some researchers in Germany are investigating mistletoe extracts as a treatment for AIDS-related cancers in women.

Complementary therapies are used in the treatment of AIDS-related cancers to help patients keep up their will to live; to cope with such side effects as depression , nausea caused by chemotherapy, concerns about disfigurement, and fear of rejection; and to gain comfort from supportive social groups. Specific complementary approaches that have been recommended for cancer patients include acupuncture, creative visualization, pet therapy, meditation, prayer, yoga, Reiki, aromatherapy, and some herbal remedies (St. John's wort for depression, peppermint or spearmint tea for nausea).

Clinical trials

As of early 2001, 39 clinical trials of treatments for AIDS-related lymphomas, 13 trials of treatment for KS, and 13 trials of treatments for PCNSL were being conducted in the United States. Thalidomide , a drug that made headlines in the 1960s for its role in causing birth defects, was shown to be effective in treating KS in July 2000. It is undergoing further study as of 2001.

See Also Immunologic therapies

Resources

BOOKS

Dollinger, Malin, Ernest H. Rosenbaum, and Greg Cable. Cancer Therapy. Kansas City, MO: Andrews and McMeel, 1994.

"Hematology and Oncology." Section 11 in The Merck Manual of Diagnosis and Therapy, edited by Mark H. Beers and Robert Berkow. Whitehouse Station, NJ: Merck Research Laboratories, 1999.

The Burton Goldberg Group. Alternative Medicine: The Definitive Guide. Fife, WA: Future Medicine Publishing, Inc., 1995.

PERIODICALS

San Francisco AIDS Foundation. Bulletin of Experimental Treatments for AIDS.

ORGANIZATIONS

AIDS Clinical Trials Group (ACTG). c/o William Duncan, Ph.D., National Institutes of Health. 6003 Executive Boulevard, Room 2A07, Bethesda, MD 20892.

American Cancer Society (ACS). 1599 Clifton Road, NE, Atlanta, GA 30329. (404) 320-3333 or (800) ACS-2345. Fax: (404) 329-7530. <http://www.cancer.org>.

National Cancer Institute, Office of Cancer Communications.31 Center Drive, MSC 2580, Bethesda, MD 20892-2580. (800) 4-CANCER. TTY: (800) 332-8615. <http://www.nci.nih.gov>.

National Institutes of Health National Center for Complementary and Alternative Medicine (NCCAM) Clearinghouse. PO Box 8218, Silver Spring, MD 20907-8218. (888) 644-6226. TTY/TDY: (888) 644-6226. Fax: (301) 495-4957. <http://nccam.nih.gov>.

San Francisco AIDS Foundation (SFAF). 995 Market Street, #200, San Francisco, CA 94103. (415) 487-3000 or (800) 367-AIDS. Fax: (415) 487-3009. <http://www.sfaf.org>.

OTHER

<http://www.hivchannel.com>.

<http://www.oncologychannel.com>.

The Body: An AIDS and HIV Information Resource. <http://www.thebody.com>.

WEB SITES WITH INFORMATION IN SPANISH

Cancer Care. <http://www.cancercareinc.org>.

New York Online Access to Health (NOAH). <http://www.noah.cuny.edu>.

Rebecca J. Frey, Ph.D.

KEY TERMS

Blood-brain barrier

—A layer of tightly packed cells in the small blood vessels in the brain that prevent many medications and other substances from entering the brain.

Burkitt's lymphoma

—A subtype of non-Hodgkin's lymphoma that is one thousand times more common in AIDS patients than in the general population.

Highly active antiretroviral therapy (HAART)

—A combination drug therapy for AIDS, usually consisting of three or more medications.

Human herpesvirus (HHV)

—A family of viruses that contain DNA and cause a number of diseases, including chickenpox, shingles, and genital herpes.

Human papilloma virus (HPV)

—A type of tumor-causing virus that causes genital warts and is associated with AIDS-related cervical cancers in women.

Kaposi's sarcoma (KS)

—The most common type of AIDS-related cancer. KS is characterized by purplish or brownish spots on the skin and may spread to the internal organs.

Lymphatic system

—The system of glands, tissues, and vessels in the body that produces lymphocytes and circulates them through the body in a clear, yellowish fluid called lymph.