Mem Inst Oswaldo Cruz, Rio de Janeiro, VOLUME 115 | JUNE 2020
Increased platelet distribution width and reduced IL-2 and IL-12 are associated with thrombocytopenia in Plasmodium vivax malaria [ACCEPTED ARTICLES / PRELIMINARY VERSION]
1Programa de Pós-Graduação em Medicina Tropical, Universidade do Estado do Amazonas (UEA), Manaus, AM, Brasil
2Instituto de Pesquisa Clínica Carlos Borborema, Fundação de Medicina Tropical Dr. Heitor Vieira Dourado (FMT-HVD), Manaus, Amazonas, Brasil
3Diretoria de Ensino e Pesquisa, Fundação Hospitalar de Hematologia e Hemoterapia do Amazonas (HEMOAM), Manaus, AM, Brasil
4Programa de Pós-Graduação em Ciências Aplicadas à Hematologia, Universidade do Estado do Amazonas (UEA), Manaus, AM, Brasil
5Programa de Pós-Graduação em Imunologia Básica e Aplicada, Universidade Federal do Amazonas (UFAM), Manaus, AM, Brasil
6Instituto Leônidas & Maria Deane, Fundação Oswaldo Cruz, Manaus, Amazonas, Brasil
7Grupo Integrado de Pesquisas em Biomarcadores, Centro de Pesquisas René Rachou (CPqRR-FIOCRUZ/ MG), Belo Horizonte, Minas Gerais, Brasil
8Laboratório de Biologia e Imunologia de Doenças Infecciosas e Parasitárias, Instituto René Rachou, Fundação Oswaldo Cruz, Belo Horizonte, Minas Gerais, Brasil
9Faculdade de Medicina, Universidade Nilton Lins, Manaus, AM, Brasil
10Instituto de Biologia, Universidade Estadual de Campinas, SP, Brasil
BACKGROUND Thrombocytopenia in malaria involves platelet destruction and consumption; however, the cellular response underlying this phenomenon has still not been elucidated.
OBJECTIVE To find associations between platelet indices and unbalanced Th1/Th2/Th17 cytokines as a response to thrombocytopenia in Plasmodium vivax infected (Pv-MAL) patients.
METHODS Platelet counts and quantification of Th1/Th2/Th17 cytokine levels were compared in 77 patients with uncomplicated P. vivax malaria and 37 healthy donors from the same area (endemic control group, ENCG).
RESULTS Thrombocytopenia was the main manifestation in 55 patients but was not associated with parasitemia. The Pv-MAL patients showed increases in the mean platelet volume (MPV), which may be consistent with larger or mega platelets. Contrary to the findings regarding the endemic control group, MPV and platelet distribution width (PDW)did not show an inverse correlation, due the increase in the heterogeneity of platelet width. In addition, the Pv-MAL patients presented increased IL-1β and reduced IL-12p70 and IL-2 serum concentrations. Furthermore, the reduction of these cytokines was associated with PDW values.
CONCLUSIONS Our data demonstrate that an increase in MPV and the association between reductions of IL-2 and IL-12 and PDW values may be an immune response to thrombocytopenia in uncomplicated P.vivax malaria.