title: Occurrence of Leishmania donovani parasitemia in plasma of infected hamsters.
abstract: Intracardiac transfusion of plasma, mononuclear cell fraction and blood of infected hamster donors induced visceral leishmaniasis in normal hamster receptors. At the moment of transfusion, the donors already showed all the typical signs of the disease: ascites, cachexia, as well as splenomegaly and a high parasite load in the spleen and liver. All transfused hamsters developed typical visceral leishmaniasis between 90 and 120 days, indicating that all blood products were infectious. Transfusion of the mononuclear cell fraction induced the highest values of parasitic load (spleen, 766 Leishman Donovan Units (LDU); liver, 2650 LDU), splenomegaly and hepatomegaly (spleen-liver/body relative weight: 1.130 and 6.870, respectively). Animals that received the plasma fraction also developed visceral leishmaniasis, showing similar parasitic load (spleen, 107 LDU; liver, 220 LDU) and spleen-liver/body relative weight (1.005 and 6.35, respectively) than those transfused with whole blood. The finding of typical Leishmania donovani infection in animals transfused with plasma demonstrates the possibility of the extracellular location of parasites, free in this blood fraction deprived of red and white blood cells. Fluorescence-assisted cell sorter analysis (FACS) of plasma showed the presence of particles corresponding in size to amastigotes, which fluoresced strongly with the serum of a patient with Kala-azar (73%), but not with normal serum.
authors.affiliation: Instituto de Microbiologia, 'Professor Paulo de Góes', Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro (UFRJ), Cidade Universitária, Ilha do Fundão, Caixa Postal 68040, CEP 21941-590, Rio de Janeiro, Brazil.
authors.forename: E
authors.initials: E
authors.lastname: Paraguai de Souza
authors.forename: A P
authors.initials: AP
authors.lastname: Esteves Pereira
authors.forename: F C
authors.initials: FC
authors.lastname: Machado
authors.forename: M F
authors.initials: MF
authors.lastname: Melo
authors.forename: T
authors.initials: T
authors.lastname: Souto-Padrón
authors.forename: M
authors.initials: M
authors.lastname: Palatnik
authors.forename: C B
authors.initials: CB
authors.lastname: Palatnik-de-Sousa
mesh_terms: D000818:Animals; D000953:Antigens, Protozoan / Q000032:analysis; D016913:Blood Component Transfusion; D001803:Blood Transfusion; D006224:Cricetinae; D004195:Disease Models, Animal; D005260:Female; D005455:Fluorescent Antibody Technique; D007106:Immune Sera; D007893:Leishmania donovani / Q000276:immunology / Q000302:isolation & purification; D007898:Leishmaniasis, Visceral / Q000469:parasitology / Q000635:transmission*; D010949:Plasma / Q000469:parasitology*
chemical_list: D000953:Antigens, Protozoan; D007106:Immune Sera