IMMUNODEFICIENCY 1.2 Flashcards
ASSESSMENT AND DIAGNOSTIC METHODS-MEDICAL MANAGEMENT
ASSESSMENT AND DIAGNOSTIC METHODS
- Enzyme immunoassay (EIA)
- Western Blot
- Viral Load Test
- OraSure Saliva Test
- OraQuick Rapid HIV-1 antibody test
ASSESSMENT AND DIAGNOSTIC METHOD:
- Formerly enzyme-linked immunosorbent assay [ELISA]
- One of the most commonly used tests to screen for HIV antibodies. This test detects antibodies that the body produces in response to HIV infection
Enzyme Immunoassay (EIA)
ASSESSMENT AND DIAGNOSTIC METHOD:
- A blood sample is taken from the individual, and the test is performed in a laboratory. The test uses antigens from HIV to capture any antibodies present in the blood.
- If the test detects antibodies, it produces a positive result.
- However, because this is a screening test, any positive result must be confirmed by a more specific test, such as the Western blot assay.
Enzyme Immunoassay (EIA)
ASSESSMENT AND DIAGNOSTIC METHOD:
FALSE POSITIVE RESULT OF Enzyme Immunoassay (EIA)
- Cross-Reactivity
- Recent Vaccination
- Technical Errors
- Biological Factors
ASSESSMENT AND DIAGNOSTIC METHOD:
FALSE NEGATIVE RESULT OF Enzyme Immunoassay (EIA)
- Window Period
- Test Sensitivity
- Genetic Variants of HIV
FALSE POSITIVE RESULT:
Improper handling, contamination, or incorrect interpretation of the test results
Technical Errors
FALSE POSITIVE RESULT:
Can sometimes react with antibodies produced in response to other infections or conditions such as autoimmune disorders or other viral infections (EBV)
Cross-Reactivity
FALSE POSITIVE RESULT:
Rarely, individuals may naturally produce proteins that mimic HIV antibodies
Biological Factors
FALSE POSITIVE RESULT:
Can sometimes trigger the production of antibodies that cross-react with HIV antigens
Recent Vaccination
FALSE NEGATIVE RESULT:
The time between initial HIV infection and the point when the body produces enough antibodies to be detected by the EIA.
Window Period
FALSE NEGATIVE RESULT:
Antibody levels are very low in cases of early HIV infection and advanced HIV infection.
Test Sensitivity
ASSESSMENT AND DIAGNOSTIC METHODS:
- The confirmatory test for HIV.
- It is more specific than the EIA and is used to confirm the presence of HIV antibodies after a positive EIA test.
Western Blot
FALSE NEGATIVE RESULT:
Incorrect sample handling, dilution errors
Technical Errors
FALSE NEGATIVE RESULT:
While rare, certain genetic variants of HIV might not be detected by the antigens used in the standard EIA
Genetic Variants of HIV
ASSESSMENT AND DIAGNOSTIC METHODS:
Target Amplification Methods of Viral Load Test
- Polymerase Chain Reaction (PCR)
- Branched DNA (bDNA) Test
ASSESSMENT AND DIAGNOSTIC METHODS:
- The test separates viral proteins by size using gel electrophoresis, and these proteins are then transferred to a membrane where they are exposed to the patient’s serum.
- If HIV antibodies are present, they will bind to the viral proteins, confirming the infection.
Western Blot
ASSESSMENT AND DIAGNOSTIC METHODS:
The test is highly specific and is used to avoid false positives that might occur with the EIA.
Western Blot
Interpretation: A positive Western blot test confirms an HIV infection.
ASSESSMENT AND DIAGNOSTIC METHODS:
- Viral load tests measure the amount of HIV RNA in the blood, rather than antibodies.
- These tests are often used to monitor the effectiveness of antiretroviral therapy (ART) and to determine the stage of the infection.
Viral Load Test
Target Amplification Methods of Viral Load Test
Detects HIV RNA by amplifying small amounts of viral RNA to detectable levels.
Polymerase Chain Reaction (PCR)
Target Amplification Methods of Viral Load Test
Measures the amount of HIV RNA in a sample using a signal amplification method.
Branched DNA (bDNA) Test
ASSESSMENT AND DIAGNOSTIC METHODS
Low or undetectable levels suggest effective suppression of the virus
Viral Load Test
Interpretation: High viral load levels indicate active viral replication and a higher risk of disease progression.
ASSESSMENT AND DIAGNOSTIC METHODS
- A non-invasive method that uses a saliva sample to detect HIV antibodies.
- It is useful for individuals who are reluctant to provide a blood sample.
OraSure Saliva Test
ASSESSMENT AND DIAGNOSTIC METHODS
A special collection device is used to obtain a saliva sample from the gums and inner cheek. The sample is then tested in a laboratory.
OraSure Saliva Test
Interpretation: A positive result indicates the presence of HIV antibodies and should be confirmed with a blood-based test, such as the Western blot.
ASSESSMENT AND DIAGNOSTIC METHODS
A rapid point-of-care test that provides results within 20-40 minutes. It can be performed using a blood sample or an oral fluid sample.
OraQuick Rapid HIV-1 antibody test
ASSESSMENT AND DIAGNOSTIC METHODS
For the oral test, the device is swabbed along the gums, and the sample is placed in a solution. For the blood test, a small blood sample is taken from the finger.
OraQuick Rapid HIV-1 antibody test
ASSESSMENT AND DIAGNOSTIC METHODS
The rapid test is widely used for its convenience, especially in settings where quick results are needed.
OraQuick Rapid HIV-1 antibody test
Interpretation: A positive result on the OraQuick test should be confirmed with a follow-up laboratory test.
MEDICAL MANAGEMENTS FOR AIDS
- Antiretroviral Therapy (ART)
- Treatment of Opportunistic Infection
MEDICAL MANAGEMENTS FOR AIDS:
A combination of medications that target the HIV.
ITS GOAL INCLUDES:
* To reduce the viral load in the body to undetectable levels
* To maintain or increase the number of CD4+ T cells
* To prevent the progression of HIV to AIDS
* To manage or prevent opportunistic infections and complications.
Antiretroviral Therapy (ART)
Examples of Opportunistic Infection
- Pneumocystis Pneumonia
- Mycobacterium Avium Complex
- Cryptococcal Meningitis
- CMV Retinitis
- Other Infections:
- - Herpes simplex or herpes zoster
- - Esophageal or oral candidiasis
CMV Retinitis:
Adverse reaction to Ganciclovir:
Severe Neutropenia
- Treatment of choice for Pneumocystis Pneumonia (PCP)
- Adjunctive corticosteroids should be started as early as possible (and certainly within 72 hours).
Trimethoprim-sulfamethoxazole (TMP-SMZ)
MEDICAL MANAGEMENT:
- A synthetic analog of somatostatin
- Shown to be effective in managing chronic severe diarrhea
Octreotide acetate (Sandostatin)
Antidiarrheal Therapy
CMV Retinitis:
Adverse reactions to Foscarnet:
- Nephrotoxicity
- Electrolyte imbalances -life threatening.
MEDICAL MANAGEMENT:
Treatment Goals:
* reduce symptoms by decreasing the size of the skin lesions
* reduce discomfort associated with edema and ulcerations
* control symptoms associated with mucosal or visceral involvement.
Chemotherapy
Kaposi’s Sarcoma
MEDICAL MANAGEMENT:
Radiation therapy is effective as a palliative measure; alphainterferon can lead to tumor regression and improved immune system function.
Chemotherapy
Kaposi’s Sarcoma
MEDICAL MANAGEMENT:
Treatment of depression involves psychotherapy integrated with pharmacotherapy antidepressants and possibly a psychostimulant
Antidepressant Therapy
MEDICAL MANAGEMENT:
For patients with severe depression who do not respond to pharmacologic interventions.
Electroconvulsive therapy
MEDICAL MANAGEMENT:
- Calorie counts should be obtained to evaluate nutritional status and initiate appropriate therapy for patients experiencing unexplained weight loss.
- Appetite stimulants can be used in patients with AIDS related anorexia.
- Oral supplements may be used to supplement diets that are deficient in calories and protein.
Nutrition Therapy
What kind of diet should a patient with diarrhea consume?
A diet low in fat, lactose, insoluble fiber, and caffeine and high in soluble fiber