Acquired immunodeficiency syndrome/AIDS: Progressive weakening of cell mediated (T-cell) immunity, AIDS heightens susceptibility to opportunistic infections and unusual cancers. Diagnosis rests on correlation of the patient's history and clinical features rather than on laboratory criteria. The time between probable exposure to the causative human immunodeficiency virus (HIV) and diagnosis averages 1 to 3 years. Incubation time for children appears to be shorter.
Studies shows more than 75% of AIDS patients die within 2 years of diagnosis. Some patients, though, have AIDS-related complex (ARC). In this condition, the patient's signs and symptoms suggest AIDS and laboratory tests reveal HIV antibodies. However, no opportunistic infections or neoplasms exist.
Clinical profile differ between adults and children with AIDS. For instance, pediatric patients rarely develop Kaposi's sarcoma, B-cell lymphoma, or acute mononucleosis-like symptoms. Children with AIDS usually don't develop hepatitis B or peripheral lymphopenia.
Pediatric AIDS patients do, however, experience problems that are uncommon or milder in affected adults. These include hypergammaglobulinemia, lymphoid interstitial pneumonitis, serious bacterial infection, and progressive neurologic disease caused by CNS infection. Pediatric patients may also have dysmorphic facial features. They may exhibit a normal ratio of T-helper to T-suppressor cells, although they will have fewer T-helper cells than normal.
Causes: The retrovirus HIV causes AIDS. This virus appears in body fluids, such as blood and semen. Modes of transmission include sexual contact, especially associated with trauma to the rectal or vaginal mucosa; transfusion of contaminated blood or blood products; and use of contaminated needles. The virus can also be transmitted perinatally from mother to fetus.
Risk factors include multiple sexual contacts with homosexual and bisexual men, heterosexual contact with someone who has AIDS or is at risk for it, present or past abuse of I.V. drugs, and transfusions of blood or blood products, Multiple sex partners increases the risk of AIDS. Prenatal an perinatal exposure to AIDS also increases the risk of AIDS in infants. Breast feeding if the mother has AIDS or is at risk of it.
Symptoms vary widely. Nonspecific ones often precede complications
and may include:
Patient may be asymptomatic until abrupt onset of complications, such as opportunistic infections, HIV encephalopathy, and Kaposi's sarcoma (see below)
A child with AIDS may exhibit dysmorphic features.
Diagnostic tests: two HIV antibody tests detect antibodies to the virus responsible for AIDS: the enzyme-linked immunosorbent assay (ELISA) and the Western blot assay.
NOTE: A positive result indicates previous exposure to the virus and means the patient may be contagious and capable of transmitting the virus; it doesn't mean that he has or will get ARC or AIDS.
An antigen test, known as the HIVAGEN test, can detect antigens to HIV (HIV p24 core protein) as early as 2 weeks after infection. Patients who test positive for HIV antibodies and carry the antigen may be more apt to develop AIDS than patients who carry antibodies only. The presence of HIV antigen along with HIV antibody indicated that the virus is actively replicating.
Currently no cure exists for AIDS. However, researchers continue to explore methods to arrest growth of HIV or to restore lost immune function.
Kaposi's Sarcoma: is characterized by purple or blue patches, plaques, or nodular skin lesions that spread widely in patients with AIDS. The lesions occur most commonly in the skin, oral mucosa, lymph nodes, GI tract, lungs, and visceral organs. Although they seldom drain or bleed, the lesions can cause other problems. GI lesions are associated with diarrhea, nausea, anorexia, and weight loss. Lung lesions are associated with congestion and difficulty breathing. Lymphatic system lesions are associated with severe facial and extremity swelling with secondary pain.
Currently, many experimental protocols are being used to treat Kaposi's sarcoma.
Surgical incision may remove skin lesions, with no need for further treatment.
Local irradiation usually has proved effective when tumors require further treatment.
Chemotherapeutic agents, including doxorubicin, vinblastine, bleomycin, interferon, and interleukin-2, are also used with some success.
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