Clinical characteristics of platelet-mediated killing circulating parasite of major human malaria

Dewu Bi; Xiaodong Huang; Lü Lin; Xike Tang; Yuexi Lu; Zhenxu Lan; Shunda Luo; Jianyan Lin; Xiaocheng Luo

doi:10.1080/07853890.2023.2221453

Clinical characteristics of platelet-mediated killing circulating parasite of major human malaria

Ann Med. 2023 Dec;55(1):2221453. doi: 10.1080/07853890.2023.2221453.

Authors

Dewu Bi^{1

2}, Xiaodong Huang^{1

2}, Lü Lin^{1

2}, Xike Tang^{1

2}, Yuexi Lu^{1

2}, Zhenxu Lan^{1

2}, Shunda Luo^{1

2}, Jianyan Lin^{1

2}, Xiaocheng Luo^{1

2}

Affiliations

¹ The Fourth People's Hospital of Nanning, Nanning, China.
² Guangxi AIDS Clinical Treatment Center (Nanning), Nanning, China.

Abstract

Objective: Microscopy was used to characterize platelet-Plasmodium-infected erythrocyte interactions in patients infected with Plasmodium falciparum, Plasmodium vivax, Plasmodium ovale or Plasmodium malariae, and to investigate the relationship between platelet-associated parasite killing and parasite clearance.

Methods: Data from 244 malaria patients admitted to the Fourth People's Hospital of Nanning between 1 January 2011 and 30 September 2022, and 45 healthy controls, were collected prospectively and assessed retrospectively. Characteristics of platelet-erythrocyte interactions were visualized by microscopy, and blood cell count and clinical profiles of these participants were obtained from the electronic medical records. ANOVA, contingency tables and Cox proportional hazards regression models were used to do statistical analysis on the subgroups.

Results: Platelet enlargement and minor pseudopodia development were observed. Platelets were found directly attaching to parasitized erythrocytes by all Plasmodium species studied, especially mature stages, and lysis of parasitized erythrocytes was connected to platelet-mediated cytolysis. Platelet counts were correlated inversely with parasitaemia and duration of parasite clearance. Artemisinin combination therapy was more effective than artemisinin alone in clearing Plasmodium in patients with thrombocytopenia.

Conclusions: Platelet-parasitized erythrocytes cell-to-cell contacts initiated platelet-associated parasite killing and helped to limit Plasmodium infection in cases of human malaria. The weakening platelet-associated parasite killing effects could be counteracted by artemisinin combination therapy in patients with thrombocytopenia.

Keywords: Plasmodium; erythrocytes; malaria; parasite killing; platelets.

Plain language summary

HighlightsPlatelets directly attaching to parasitized erythrocytes.Platelets correlated inversely with parasitaemia and duration of parasite clearance.Artemisinin combination therapy was more effective than artemisinin alone.Weakening killing effects may counteract by artemisinin combination therapy.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Artemisinins*
Blood Platelets
Humans
Malaria* / drug therapy
Parasites*
Retrospective Studies
Thrombocytopenia*

Substances

artemisinin
Artemisinins

Grants and funding

This study was supported by the Key Research and Development Program of Nanning municipal Science and Technology Department [Grant Number 20193008], the Guangxi Zhuang Region Health Department [Grant Number Z20200979] and the Fourth People’s Hospital of Nanning Youth Foundation [Grant Number NNSY2021010].