Issue |
Ann. Parasitol. Hum. Comp.
Volume 68, Number 4, 1993
|
|
---|---|---|
Page(s) | 169 - 175 | |
DOI | https://doi.org/10.1051/parasite/1993684169 | |
Published online | 12 August 2016 |
Mémoire
Falciparum malaria in naturally infected human patients: IV-Ultrastructural changes in peripheral white blood cells
Paludisme à P. falciparum. IV-Altérations ultrastructurales des globules blancs périphériques
Department of Pathology, College of Medicine, King Saud University, Abha PO Box 641, Saudi Arabia.
Accepted: 23 February 1993
Ultrastructure of white blood cells (WBC) were studied in peripheral venous blood from Saudi patients with acute falciparum malaria (AFM) and compared with their counterparts in same patients 2 weeks after chloroquine treatment and full recovery. A counting system was incorporated to determine the rate of abnormal to normal cell type in plastic thick sections during the course of the disease. Neutrophilia, monocytosis, eosinopenia and lymphocytosis were associated with various ultrastructural abnormalities including: (1) Knobby phagocytic polymorphnuclear neutrophils (PMN) and promyelocytes, and PMN with highly vacuolated cytoplasm. (2) Irregularly outlined electron-dense nuclei in non-functional monocytes. (3) Unusual distribution of nuclear chromatin in resting B-lymphocytes, while others possess highly vacuolated cytoplasm and knobby surfaces. (4) Absence of granules in granular lymphocytes containing the known diagnostic paratubular crystalline arrays. (5) Plasmablasts containing electron-dense granules and swollen mitochondria. These abnormalities were suggested to be due to the high level of parasitaemia producing some toxic soluble products. They may also be attributed to alteration of bone marrow macrophages as a sequence of their interaction with soluble parasite products or their phagocytic parasitized red cells and debris released during the rupture of schizonts. This study showed that the number of abnormal WBC increases in patients with high level of parasitaemia; plasmablasts have the lowest rate of abnormalities, while monocytes have the highest; old patients present with lower degree of parasitaemia than young patients due to a less mature immune system; and the AFM may have independent effects on the structure of human WBC.
Résumé
L’ultrastructure des globules blancs est étudiée dans le sang veineux périphérique chez des malades d’Arabie Saoudite atteints de paludisme aigu à falciparum. Elle est comparée à celle des globules blancs chez les mêmes malades deux semaines après traitement à la chloroquine et guérison totale.
Des comptages ont été réalisés sur coupes semi-fines pour déterminer le pourcentage d’anomalies cellulaires pendant le cours de la maladie. Neutrophilie, monocytose, éosinopénie et lymphocytose étaient associées à diverses anomalies ultrastructurales : 1) protubérances de l’enveloppe évoquant des knobs chez les promyélocytes, parfois associées à un cytoplasme très vacuolisé chez les polynucléaires neutrophiles ; 2) contour nucléaire irrégulièrement dense chez les monocytes non fonctionnels ; 3) distribution anormale de la chromatine nucléaire dans certains lymphocytes B au repos, tandis que d’autres ont un cytoplasme vacuolisé et une surface rugueuse ; 4) absence de granules chez les lymphocytes granuleux contenant les structures cristallines paratubulaires ; 5) granules denses et mitochondries gonflées dans les plasmoblastes.
Cette étude montre que, le nombre de globules blancs anormaux augmente chez les patients ayant de fortes parasitémies, les monocytes ont plus d’anomalies que les plasmoblastes, les malades âgés ont une parasitémie plus faible que les jeunes ce qui est dû à un système immunitaire plus mûr, et que, les effets du paludisme aigu à falciparum sur les globules blancs peuvent être sous la dépendance de mécanismes variés.
Key words: Falciparum malaria / Peripheral blood / White cells / Ultrastructural changes
Mots clés : Paludisme à falciparum / Sang périphérique / Globules blancs / Altérations ultrastructurales
© Masson, Paris 1993, transferred to Société Française de Parasitologie
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