title: High levels of T lymphocyte activation in Leishmania-HIV-1 co-infected individuals despite low HIV viral load.
abstract: BACKGROUND
  Concomitant infections may influence HIV progression by causing chronic activation leading to decline in T-cell function. In the Americas, visceral (AVL) and tegumentary leishmaniasis (ATL) have emerged as important opportunistic infections in HIV-AIDS patients and both of those diseases have been implicated as potentially important co-factors in disease progression. We investigated whether leishmaniasis increases lymphocyte activation in HIV-1 co-infected patients. This might contribute to impaired cellular immune function.
  
  
  METHODS
  To address this issue we analyzed CD4+ T absolute counts and the proportion of CD8+ T cells expressing CD38 in Leishmania/HIV co-infected patients that recovered after anti-leishmanial therapy.
  
  
  RESULTS
  We found that, despite clinical remission of leishmaniasis, AVL co-infected patients presented a more severe immunossupression as suggested by CD4+ T cell counts under 200 cells/mm3, differing from ATL/HIV-AIDS cases that tends to show higher lymphocytes levels (over 350 cells/mm3). Furthermore, five out of nine, AVL/HIV-AIDS presented low CD4+ T cell counts in spite of low or undetectable viral load. Expression of CD38 on CD8+ T lymphocytes was significantly higher in AVL or ATL/HIV-AIDS cases compared to HIV/AIDS patients without leishmaniasis or healthy subjects.
  
  
  CONCLUSIONS
  Leishmania infection can increase the degree of immune system activation in individuals concomitantly infected with HIV. In addition, AVL/HIV-AIDS patients can present low CD4+ T cell counts and higher proportion of activated T lymphocytes even when HIV viral load is suppressed under HAART. This fact can cause a misinterpretation of these laboratorial markers in co-infected patients.
authors.affiliation: Laboratório Interdisciplinar de Pesquisas Médicas, Instituto Oswaldo Cruz -FIOCRUZ, Av, Brasil 4365, Rio de Janeiro CEP 21040-360, Brazil.
authors.forename: Joanna R
authors.initials: JR
authors.lastname: Santos-Oliveira
authors.forename: Carmem B W
authors.initials: CB
authors.lastname: Giacoia-Gripp
authors.forename: Priscilla
authors.initials: P
authors.lastname: Alexandrino de Oliveira
authors.forename: Valdir S
authors.initials: VS
authors.lastname: Amato
authors.forename: Jose Ângelo L
authors.initials: JÂ
authors.lastname: Lindoso
authors.forename: Hiro
authors.initials: H
authors.lastname: Goto
authors.forename: Manoel P
authors.initials: MP
authors.lastname: Oliveira-Neto
authors.forename: Marise S
authors.initials: MS
authors.lastname: Mattos
authors.forename: Beatriz
authors.initials: B
authors.lastname: Grinsztejn
authors.forename: Mariza G
authors.initials: MG
authors.lastname: Morgado
authors.forename: Alda M
authors.initials: AM
authors.lastname: Da-Cruz
mesh_terms: D051997:ADP-ribosyl Cyclase 1 / Q000032:analysis; D000328:Adult; D000569:Americas; D018791:CD4 Lymphocyte Count; D016516:CD4-CD8 Ratio; D018414:CD8-Positive T-Lymphocytes / Q000737:chemistry; D005260:Female; D015658:HIV Infections / Q000150:complications* / Q000276:immunology* / Q000821:virology; D015497:HIV-1; D006801:Humans; D007896:Leishmaniasis / Q000150:complications* / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D013601:T-Lymphocytes / Q000276:immunology*; D019562:Viral Load
chemical_list: D051997:ADP-ribosyl Cyclase 1