HIV Lifecycle
What receptor and coreceptor does HIV use to enter CD4⁺ T cells?
CD4 and either CCR5 or CXCR4
What CD4⁺ T-cell count is generally used as the threshold for AIDS when an AIDS-defining condition is absent?
<200 cells/µL
At what CD4 count and with which antibiotic do you prophylactically treat for Pneumocystis jirovecii?
CD4< 200 and with Bactrim
What is the mechanism of action of Maraviroc?
CCR5 antagonist (Entry Inhibitor)
What type of cell is implicated in Hodgkin Lymphoma?
Mature B cells
What HIV enzyme converts viral RNA into double-stranded DNA?
Reverse transcriptase
What does the phrase "CSF Escape" refer to when discussing the pathophysiology of HIV encephalopathy?
HIV RNA can be detectable in the CSF but undetectable in the blood
An HIV patient with a CD4 count of 40 develops fever, night sweats, weight loss, and diarrhea. Acid-fast organisms are found within macrophages. Which organism is most likely?
Mycobacterium avium complex (MAC)
What is the combination of drug classes used most often for ART?
2 NRTIs + 1 NNRTI or 1 PI or 1 INI
Which type of non-Hodgkin Lymphoma is associated with a t(14:18)?
Follicular Lymphoma
What proteins are encoded for by the gag gene?
p24 (capsid) and p17 (matrix)
HIV viral proteins can cause direct neurotoxicity. When discussing HIV myelopathy, what cell type are the viral proteins directly affecting?
Oligodendrocytes
An HIV patient with a CD4 count of 180 develops fever, dry cough, and progressive dyspnea. Chest imaging shows diffuse bilateral interstitial infiltrates. What is the most likely organism?
Pneumocystis jirovecii
What is the side effect specific to Efavirenz?
Vivid Dreams
What factor is overexpressed in Mantle Cell Lymphoma?
A patient has HIV that primarily infects macrophages and memory CD4⁺ T cells early in infection. Which coreceptor is most likely being used?
CCR5
What are the three AIDS-defining cancers?
Kaposi Sarcoma, Cervical Cancer, and non-Hodgkin Lymphoma
An HIV patient with a CD4 count of 70 develops headache, fever, and multiple ring-enhancing lesions in the brain, particularly involving the basal ganglia. What is the most likely diagnosis?
Toxoplasmosis
Mutation to the pol gene can provide resistance to which two classes of antiretrovirals?
Protease Inhibitors and NRTIs
A histology slide shows "clear spaces interspersed with debris-laden reactive histiocytes, consistent with a starry sky pattern." What type of lymphoma is this most consistent with?
Burkitt Lymphoma
What mutation would confer resistance to the M tropic HIV strain?
homozygous CCR5 deletion
An untreated HIV patient develops fever, weight loss, lymphadenopathy, and a CD4 count of 80 cells/µL. Biopsy shows spindle-shaped cells forming vascular channels containing extravasated RBCs. What viral infection is driving this lesion?
HHV-8, causing Kaposi sarcoma
A biopsy from an immunocompromised patient shows numerous small, narrow-based budding yeast forms within macrophages. Which fungal organism is most likely responsible?
Histoplasma capsulatum
An HIV patient is started on abacavir. Before treatment, what genetic test should be performed to reduce the risk of a severe hypersensitivity reaction?
HLA-B*5701
An HIV patient develops headaches and focal neurologic deficits. Imaging shows a solitary enhancing lesion in the brain. Biopsy reveals a B-cell lymphoma associated with EBV. What is the diagnosis?
Primary CNS lymphoma