Human immunodeficiency virus (HIV)
Hung N. Winn, Frank A. Chervenak, Roberto Romero in Clinical Maternal-Fetal Medicine Online, 2021
HIV belongs to the family of human retroviruses (Retroviridae) and the subfamily of lentiviruses. HIV-1 is the predominant cause of HIV disease in the world. HIV-2, which can also cause AIDS, is closely related to simian immunodeficiency virus and is largely confined to West Africa, although occasional cases occur worldwide. The HIV virion is an icosahedral structure containing numerous external spikes formed by the two major envelope proteins, the external gp120, and the transmembrane gp41. The virion attaches via gp120 to cells expressing the CD4 molecule, which acts as the cell receptor for the virus. The CD4 molecule is expressed mainly in a subset of T lymphocytes responsible for helper function in the immune system, but can also be found on the surface of monocytes/macrophages and dendritic/Langerhans cells (13). A conformational change then occurs in the gp120 molecule, allowing it to bind to one of two cellular coreceptors (CCR5 or CXCR4). Binding is followed by insertion of viral gp41 into the CD4 cell, resulting in membrane fusion followed by release of the viral core into the cell cytoplasm.
The thiols glutathione, cysteine, and homocysteine in human immunodeficiency virus (HIV) infection
Ronald R. Watson in NUTRIENTS and FOODS in AIDS, 2017
Infection with human immunodeficiency virus type 1 (hereafter referred to as HIV) results in a progressive impairment of immune function, ultimately leading to opportunistic infections and malignancies of the acquired immunodeficiency syndrome (AIDS). The fundamental immunologic abnormality is a progressive impairment of the number and functions of CD4+ lymphocytes. Because the CD4+ lymphocytes are important immune regulatory cells, various immune functions are affected. In recent years, several reports have suggested that impaired antioxidant defense plays a role in the immunopathogenesis of HIV infection.1–5 Several investigators have suggested that clinical trials with antioxidants, in particular with glutathione replenishing drugs, should be carried out.6–9
AIDS and other acquired immunodeficiencies
Gabriel Virella in Medical Immunology, 2019
Eventually the CD4 T-cell count declines and symptomatic disease emerges. During the early symptomatic phase, CDC category B, constitutional symptoms including fevers, night sweats, fatigue, chronic diarrhea, and headache are common. Clinical symptoms of oral candidiasis, herpes zoster (shingles), thrombocytopenia, pelvic and rectal abscesses, and peripheral neuropathy are among the conditions seen during this disease stage. CD4 counts are generally in the 200–500 cells/μL range. During asymptomatic HIV infection coinfections such as syphilis, hepatitis B, and tuberculosis can accelerate HIV progression. Similarly, HIV infection often results in reactivation of latent tuberculosis. Coinfection with human papillomaviruses (HPVs) and increased risk for the development of cervical and anal carcinoma is common.
U.S. Hospitalization rates and reasons stratified by age among persons with HIV 2014–15
Published in AIDS Care, 2020
Julia Fleming, Stephen A. Berry, Richard D. Moore, Ank Nijhawan, Charurut Somboonwit, Laura Cheever, Kelly A. Gebo
We analyzed several covariates thought to be associated with hospitalization rate. Subjects’ age was categorized as 18–29, 30–39, 40–49, 50–59, and ≥ 60 years, as of July 1st of each study year. Sex was defined as male or female; other/unknown sex (3) was excluded from the study population due to small numbers. Race and ethnicity were categorized as non-Hispanic black (“black”), non-Hispanic white (“white”), Hispanic, and other/unknown. The racial groups Asian/Pacific Islander and American Indian comprised few subjects (644 and 68, respectively) were combined into the “other” category because of small numbers. Self-reported primary HIV risk transmission factor was defined as heterosexual contact (HET), men who have sex with men (MSM), persons who inject drugs (PWID), and other/unknown. Those with both sexual and PWID risk factors were categorized as PWID. Those with both MSM and heterosexual contact were categorized as MSM. CD4 count was categorized as ≤50 cells/mm3, 51–200 cells/mm3, 201–350 cells/mm3, and >350 cells/mm3. HIV-1 RNA was categorized as suppressed (HIV-1 RNA ≤ 200 copies/mL) and not suppressed (HIV-1 RNA >200 copies/mL). Health care coverage was categorized as public (Medicaid, Medicare, or both), private, uninsured/Ryan White HIV/AIDS Program. For CD4, HIV-1 RNA, and health care coverage, the first measurements of each calendar year were used.
Changes of peripheral lymphocyte subset in patients with SARS-CoV-2 infection during the whole course of disease
Published in Expert Review of Respiratory Medicine, 2021
CD4+ T lymphocyte cells <200/ul is a recognized threshold for people living with HIV to be prone to various opportunistic infections. In this study, the relation of levels of pro-inflammatory biomarkers and CD4+ T lymphocyte counts is shown in Table 3. The levels of CRP, IL-6 and TNF-α in COVID-19 patients had CD4+ T lymphocyte cells <200/ul was higher than in those had CD4+ T lymphocyte cells ≥200/ul (67.1 ± 5.7 vs 18.8 ± 2.1 mg/l, P < 0.001; 121.46 ± 51.09 vs 45.13 ± 30.74 pg/ml, P = 0.035; 1.01 ± 0.37 vs 0.55 ± 0.18 pg/ml, P = 0.033). However, there were no statistically significant differences in IFN-γ, IL-2, IL-4 and IL-10 between COVID-19 patients who had CD4+ T lymphocyte cells <200/ul and those who had CD4+ T lymphocyte cells ≥200/ul.
Antiretroviral treatment for HIV infection: Swedish recommendations 2019
Published in Infectious Diseases, 2020
Jaran Eriksen, Christina Carlander, Jan Albert, Leo Flamholc, Magnus Gisslén, Lars Navér, Veronica Svedhem, Aylin Yilmaz, Anders Sönnerborg
The CD4 count provides a measure of the degree of immunodeficiency and in immunodeficient patients they should be followed 2–4 times/year until stable and normal levels are achieved. In stable patients monitoring once yearly is sufficient. The CD4 count is the most important indicator for the risk of developing opportunistic infections and tumours (evidence level 2a). CD4 counts are also used to complement plasma HIV RNA levels to evaluate the effect of treatment. Both the absolute count and percentage of CD4 cells are important for assessing the immunodeficiency and treatment effect. Usually, the absolute number and percentage correlate well. The percentage can be especially useful in situations with unexpectedly high or low absolute CD4 counts, where the suspected reason is unrelated to the HIV infection.
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