High levels of CD4^sup +^ CTLA-4^sup +^ Treg cells and CCR5 density in HIV-1-infected patients with visceral leishmaniasis

• Published in: European journal of clinical microbiology & infectious diseases Vol. 34; no. 2; p. 267
• Main Authors: Vallejo, A, Abad-fernández, M, Moreno, S, Moreno, A, Pérez-elías, M J, Dronda, F, Casado, J L
• Format: Journal Article
• Language: English
• Published: Heidelberg Springer Nature B.V 01.02.2015
• Subjects: Immunology; Infections; Infectious diseases; Lymphocytes; Parasitic diseases; Pathogens; Vector-borne diseases; Madrid Spain; Spain
• ISSN: 0934-9723; 1435-4373
• DOI: 10.1007/s10096-014-2229-1

Visceral leishmaniasis (VL) in HIV-1-infected patients has been associated with poor immunological recovery and frequent disease relapses. The aim of this study was to analyse the role of T cell populations, Treg cells and CCR5 density in patients with VL compared to HIV-1-infected patients without leishmaniasis. A cross-sectional study of nine Leishmania-HIV-1-coinfected (LH) patients with VL receiving suppressive cART for at least 1 year were compared to 16 HIV-1-infected patients with non-immunological response (NIR, CD4 count below 250 cells/mm^sup 3^) and 26 HIV-1-infected patients with immunological response (IR, CD4 count above 500 cells/mm^sup 3^) without leishmaniasis. LH patients had a deep depletion of naïve T cells (p=0.002), despite similar levels of effector T cells compared to NIR patients. CD4 Treg cells were similar compared to NIR patients, but higher compared to IR patients (p<0.001). Interestingly, CD4 Treg CTLA-4^sup +^ cells were higher in LH patients compared to either NIR or IR patients (p=0.022 and p<0.001, respectively), and the CD4 Treg/TEM ratio was similar to NIR patients, but higher compared to IR patients (p=0.017). CCR5^sup +^ T cell levels were higher compared to IR patients (p<0.001), while CCR5 density on T cells were higher compared to both NIR and IR patients (p<0.005 in both cases). Higher levels of CD4^sup +^ CTLA-4^sup +^ Treg cells and CCR5 density on CD8^sup +^ T cells are strongly associated with VL in HIV-1-infected patients. Also, these patients have a poor immunological profile that might explain the persistence and relapse of the pathogen.