Alterations in Alterations in ImmunityImmunity

HIV/AIDSHIV/AIDS

HIV/AIDS

An infection caused by the human immunodeficiency virus (HIV)

Acquired immune deficiency syndrome (AIDS) represents the end stage of a continuum of HIV infection & its sequelae

HIV/AIDS

Human immunodeficiency viral particles are seen at medium magnification in this electron micrograph. Note the central core and the outer envelope.

HIV/AIDS

A human immunodeficiency viral particle is seen budding from the infected cell surface at the top, with a complete viral particle at bottom in this high magnification electron micrograph.

HIV/AIDS

The life cycle of human immunodeficiency virus is diagrammed here. Note that the reverse transcriptase enzyme makes an HIV proviral DNA that is incorporated into the host cell.

HIV/AIDS

Human immunodeficiency virus, once it enters the body, is carried to the lymphoid tissues where both CD4+ T-lymphocytes as well as follicular dendritic cells can become infected, as shown in this diagram.

Human immunodeficiency virus is shown crossing the mucosa of the genital tract to infect CD4+ T-lymphocytes. A Langerhans cell in the epithelium is shown in red in this diagram.

The life cycle of HIV shown with the points at which pharmacologic agents may block viral maturation, including points for inhibition of reverse transcriptase, integrase, TAT transcription, and protease, in this diagram.

Diagnostic Tests

ELISA Western Blot CD4 cells CD4:CD8 Viral load CBC

– RBCs– WBCs– Plts

Clinical Manifestations & Complications of AIDS

AIDS/HIV Disease: Signs and Symptoms

Shortness of breath Cough, fever Night sweats, fatigue Nausea, vomiting Weight loss Lymphadenopathy Diarrhea Pain, discomfort

Visual changes Headache Memory loss,

confusion Seizures Personality changes Dry skin, rashes,

lesions

Pneumocystis Carinii (PCP)

Pneumocystis Carinii

The appearance of Pneumocystis carinii grossly in lung is shown here. Note that this is an extensive pneumonia.

Pneumocystis Carinii

In rare cases, Pneumocystis carinii pneumonia may produce cavitary change, as shown here grossly in lung.

Cytomegalovirus (CMV)

CMV infection has no characteristic gross appearance in any organ, but it can be manifested in a variety of ways. Here is cecal ulceration.

CMV Retinitis/Wasting Syndrome

Kaposi’s Sarcoma

Kaposi’s Sarcoma & Cellulitis

Kaposi's sarcoma typically produces one or more reddish purple nodules on the skin, as seen here grossly.

Visceral involvement with Kaposi's sarcoma in AIDS is common. Here are multiple reddish nodules seen over the gastric mucosa.

Here are multiple reddish irregular masses in the liver.

Fungal Infections

Candida infections are common with AIDS, but most often appear as oral thrush, which is a nuisance but not life-threatening. Disseminated infections are uncommon, but here is a rare Candida pneumonia, which resembles a bacterial bronchopneumonia.

Candidiasis

MAC Mycobacterium avium

complex (MAC) may produce grossly visible granulomas, as seen here in the spleen. However, often there is organ enlargement, but no visible granulomas.

Mycobacterium avium complex (MAC) may produce a grossly visible yellowish-tan cut surface, as seen here in these mesenteric lymph nodes, because the mycobacteria are so numerous.

Toxoplasmosis

Toxoplasma gondii is a protozoan parasite that most often leads to infection of the brain with AIDS. The lesions are usually multiple and have the appearance of abscesses. Less commonly, T gondii infection is disseminated to other organs.

Toxoplasma gondii infection is most often manifested in the central nervous system. Multiple abscesses that are ring-enhancing with CT scans can be seen. Older abscesses can organize, as shown here grossly in brain.

Hodgkin’s Lymphoma in AIDS

Cut sections of this enlarged lymph node involved with high-grade non-Hodgkin's lymphoma in AIDS reveal a "strawberry sundae" appearance with swirls and globs of red in white. This can also be seen with extra-nodal AIDS lymphomas.

Malignant Lymphoma in AIDS

Malignant lymphoma is typically extranodal in AIDS. Seen here in small intestine are two mass lesions on the mucosal surface.

Key Management Areas

Prevent infection Pain management Nutritional support

– ↑ protein/calories– Watch fats!

Control diarrhea

Key Management Areas

Safety– Assistive devices– Home environment– Smoking

Psychosocial support– Coping– Caregiver strain– Social isolation– Disturbed thought

processes

Key Management Areas

Early detection and treatment of opportunistic diseases & symptoms– Respiratory– GI– CNS

Prevent Transmission– Risk factors

Drug Therapy

Treatment of opportunistic infections Antiretroviral Agents [Zidovudine (AZT,

Retrovir)]

– Inhibits viral replication– Combination therapy used– Many side effects– Complex protocols– Does not work for everyone