Thymic Function Impacts the Peripheral CD4/CD8 Ratio of HIV-Infected Subjects

• Published in: Clinical infectious diseases Vol. 64; no. 2; pp. 152 - 158
• Main Authors: Rosado-Sánchez, I., Herrero-Fernández, I., Genebat, M., Ruiz-Mateos, E., Leal, M., Pacheco, Yolanda M.
• Format: Journal Article
• Language: English
• Published: United States Oxford University Press 15-01-2017
• Subjects: Adult; Antiretroviral Therapy, Highly Active; ARTICLES AND COMMENTARIES; Biomarkers; CD4 Lymphocyte Count; CD4-CD8 Ratio; Female; HIV; HIV Infections - blood; HIV Infections - drug therapy; HIV Infections - immunology; HIV Infections - virology; HIV-1 - immunology; Homeostasis; Human immunodeficiency virus; Humans; Immunophenotyping; Lentivirus; Lymphocytes; Male; Morbidity; Mortality; Organ Size; Phenotype; Proteins; Retroviridae; T-Lymphocyte Subsets - immunology; T-Lymphocyte Subsets - metabolism; Thymus Gland - anatomy & histology; Thymus Gland - diagnostic imaging; Thymus Gland - physiology; Tomography, X-Ray Computed; Treatment Outcome; Viral Load; delta-TRECs; antiretroviral naive; HIV; CD4/CD8 ratio; thymic function
• ISSN: 1058-4838; 1537-6591
• DOI: 10.1093/cid/ciw711

Background. The persistence of an inverted CD4/CD8 ratio has been extensively associated with the increased morbimortality of chronic human immunodeficiency virus (HIV)-infected subjects. Thymic function is crucial for the maintenance of T cell homeostasis. We explored the impact of thymic function on the CD4/CD8 ratio of HIV-infected subjects. Methods. In a cohort of 53 antiretroviral-naive HIV-infected subjects, the measure of thymic volume, as a representative marker for thymic function, was available at baseline and at 12, 24, and 48 weeks post antiretroviral treatment. Results. Baseline thymic volume was associated with the CD4/CD8 ratio (ρ = 0.413, P = .002), being this association highly dependent on the CD4 T cell levels. In subjects who achieved undetectable viral load after treatment (n = 33), a higher baseline thymic volume was associated with a higher increase in CD4 T cell counts and a decreasing trend in CD8 T cell counts during follow-up. Moreover, the baseline thymic volume was independently associated with the normalization of the CD4/CD8 ratio after 96 weeks of treatment (odds ratio, 95% confidence interval: 1.95 (1.07–3.55); P = .03). Conclusions. Our data indicate the relevance of the remaining thymic function before the start of treatment to the CD4/CD8 ratio of HIV-infected subjects and, hence, potentially, in their clinical progression.