CD4+/CD8+ ratio

The CD4+/CD8+ ratio measures the ratio of T helper cells to cytotoxic T cells. A reduced CD4+/CD8+ ratio is associated with reduced resistance to infection.[1] Patients with tuberculosis show a reduced CD4+/CD8+ ratio.[1]

A declining CD4+/CD8+ ratio is associated with ageing, and is an indicator of immunosenescence.[2][3] A study of elderly humans showed the highest expansion of cytotoxic T cells among those with cytomegalovirus.[3]

HIV infection leads to low levels of CD4+ T cells (lowering the CD4+/CD8+ ratio) through a number of mechanisms, including pyroptosis of abortively infected T cells,[4] apoptosis of uninfected bystander cells,[5] direct viral killing of infected cells, and killing of infected CD4+ T cells by CD8 cytotoxic lymphocytes that recognize infected cells.[6] When CD4+ T cell numbers decline below a critical level, cell-mediated immunity is lost, and the body becomes progressively more susceptible to opportunistic infections.

See also

References

  1. 1 2 Yin Y, Qin J, Dai Y, Zeng F, Pei H, Wang J (2015). "The CD4+/CD8+ Ratio in Pulmonary Tuberculosis: Systematic and Meta-Analysis Article". IRANIAN JOURNAL OF PUBLIC HEALTH. 44 (2): 185–193. PMC 4401876Freely accessible. PMID 25905052.
  2. ↑ Serrano-Villar S, Moreno S, Fuentes-Ferrer M, Sánchez-Marcos C, Avila M, Sainz T, de Villar NG, Fernández-Cruz A, Estrada V (2014). "The CD4:CD8 ratio is associated with markers of age-associated disease in virally suppressed HIV-infected patients with immunological recovery". HIV Medicine. 15 (1): 40–49. doi:10.1111/hiv.12081. PMID 24007533.
  3. 1 2 Hadrup SR, Strindhall J, Køllgaard T, Seremet T, Johansson B, Pawelec G, thor Straten P, Wikby A (2006). "Longitudinal studies of clonally expanded CD8 T cells reveal a repertoire shrinkage predicting mortality and an increased number of dysfunctional cytomegalovirus-specific T cells in the very elderly". Journal of Immunology. 176 (4): 2645–2653. doi:10.1111/hiv.12081. PMID 16456027.
  4. ↑ Doitsh, Gilad; Galloway, Nicole L. K.; Geng, Xin; Yang, Zhiyuan; Monroe, Kathryn M.; Zepeda, Orlando; Hunt, Peter W.; Hatano, Hiroyu; Sowinski, Stefanie; Muñoz-Arias, Isa; Greene, Warner C. (2014). "Cell death by pyroptosis drives CD4 T-cell depletion in HIV-1 infection.". Nature. 505 (7484): 509–514. doi:10.1038/nature12940. PMC 4047036Freely accessible. PMID 24356306.
  5. ↑ Garg H, Mohl J, Joshi A (Nov 9, 2012). "HIV-1 induced bystander apoptosis". Viruses. 4 (11): 3020–43. doi:10.3390/v4113020. PMC 3509682Freely accessible. PMID 23202514.
  6. ↑ Kumar, Vinay (2012). Robbins Basic Pathology (9th ed.). p. 147. ISBN 9781455737871.


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