Módulo 2 – Curso pós-graduado – VIH e Envelhecimento

Non-AIDS Defining Cancers Among HIV Infected People

The epidemiology of non-AIDS defining cancers among HIV infected patients

Autor: Prof. Doutor Julian Falutz, MD, FRCP (McGill University Hospital Center, Montreal, Canada)

Immunosuppression, morbidity and mortality

Immunosenescence is a physiological age-related functional decline in both the adaptive and the innate immune system, which have known negative effects in the older population in terms of morbidity and mortality. The key biological elements of immunosenescence include:

  • A progressive decline in naïve T-cells within the entire T-cell subset (CD3+);
  • An accumulation of terminally differentiated T-cells with impaired memory and cytotoxic functions (both CD4+ and CD8+ CD28and CD57+ T-cells), thus corresponding to an immune senescent phenotype;
  • An increased inflammatory cytokine secretion leading to a chronic inflammatory state;
  • Shortened telomeres;
  • The chronic exposure to viral infections, particularly CMV.

Treated HIV patients 40-50 years old present accelerated immunosenescence similar to the physiologic phenome- na in HIV-negative people older than 80 years, at T-cell level, namely, decreased naïve T-cell, hyporesponsiveness, less proliferative capacity, and replicative senescence26. The factors which contribute to an accelerated state of immunosenescence in treated HIV patients may include:

  • Chronic inflammatory stimulus: T-cell activation markers are the same in younger HIV patients as in older HIV-negative controls;
  • Thymic dysfunction: thymic atrophy occurs very early in HIV patients, leading to disrupted thymic environment for normal T-cell differentiation and decreased release of mature T-cells;
  • Telomere dysfunction: shortened telomeres are a marker of replicative senescence associated with decreased survival, and similar to those of HIV-negative elderly subjects27. In ad- dition, treated HIV patients have telomere lengths in CD8+/ CD28cells much shorter than that of an age related HIV negative cohort, but similar to that of HIV negative individuals 30-40 years older28.

Hence, accelerated immunosenescence in treated HIV patients may be evidence of an accelerated aging phenotype, as opposed to the accentuated phenotype.

Logo MSD Termos de utilização | Política de Privacidade | Sobre a MSD Copyright © 2018 Todos os direitos reservados. Merck Sharp & Dohme Corp.,uma subsidiária da Merck & Co., Inc. Kenilworth, NJ, USA, conhecida fora dos EUA e Canadá como MSD. Os conteúdos disponibilizados nesta página Web são informação de carácter geral e não substituem em nenhum caso as consultas, tratamentos ou as recomendações do seu médico. INFC-1273571-0000 11/2018