dc.contributor.author | Anyona SB, SB | |
dc.contributor.author | Schrier, SL | |
dc.contributor.author | Gichuki, CW | |
dc.contributor.author | Waitumbi, JN | |
dc.date.accessioned | 2018-01-17T12:46:55Z | |
dc.date.available | 2018-01-17T12:46:55Z | |
dc.date.issued | 2006-07-31 | |
dc.identifier.citation | Anyona, S. B., Schrier, S. L., Gichuki, C. W., & Waitumbi, J. N. (2006). Pitting of malaria parasites and spherocyte formation. Malaria Journal, 5, 64. http://doi.org/10.1186/1475-2875-5-64 | en_US |
dc.identifier.uri | https://repository.maseno.ac.ke/handle/123456789/127 | |
dc.description.abstract | BACKGROUND:
A high prevalence of spherocytes was detected in blood smears of children enrolled in a case control study conducted in the malaria holoendemic Lake Victoria basin. It was speculated that the spherocytes reflect intraerythrocytic removal of malarial parasites with a concurrent removal of RBC membrane through a process analogous to pitting of intraerythrocytic inclusion bodies. Pitting and re-circulation of RBCs devoid of malaria parasites could be a host mechanism for parasite clearance while minimizing the anaemia that would occur were the entire parasitized RBC removed. The prior demonstration of RBCs containing ring-infected erythrocyte surface antigen (pf 155 or RESA) but no intracellular parasites, support the idea of pitting.
METHODS:
An in vitro model was developed to examine the phenomenon of pitting and spherocyte formation in Plasmodium falciparum infected RBCs (iRBC) co-incubated with human macrophages. In vivo application of this model was evaluated using blood specimens from patients attending Kisumu Ditrict Hospital. RBCs were probed with anti-RESA monoclonal antibody and a DNA stain (propidium iodide). Flow cytometry and fluorescent microscopy was used to compare RBCs containing both the antigen and the parasites to those that were only RESA positive.
RESULTS:
Co-incubation of iRBC and tumor necrosis factor-alpha activated macrophages led to pitting (14% +/- 1.31% macrophages with engulfed trophozoites) as opposed to erythrophagocytosis (5.33% +/- 0.95%) (P < 0.01). Following the interaction, 26.9% +/- 8.1% of the RBCs were spherocytes as determined by flow cytometric reduction in eosin-5-maleimide binding which detects RBC membrane band 3. The median of patient RBCs with pitted parasites (RESA+, PI-) was more than 3 times (95,275/muL) that of RESA+, PI+ RBCs (28,365/muL) (P < 0.01). RBCs with pitted parasites showed other morphological abnormalities, including spherocyte formation.
CONCLUSION:
It is proposed that in malaria holoendemic areas where prevalence of asexual stage parasites approaches 100% in children, RBCs with pitted parasites are re-circulated and pitting may produce spherocytes. | en_US |
dc.language.iso | en | en_US |
dc.publisher | Pub Med Central | en_US |
dc.title | Pitting of malaria parasites and spherocyte formation | en_US |
dc.type | Article | en_US |