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The extravascular compartment of the bone marrow: a niche for Plasmodium falciparum gametocyte maturation?

Farfour E, Charlotte F, Settegrana C, Miyara M, Buffet P - Malar. J. (2012)

Bottom Line: Plasmodium falciparum immature gametocytes accumulate in the bone marrow, but their exact location in this tissue remains unclear.A majority (89%) of immature stages II to IV gametocytes and a minority (29%) of mature stage V gametocytes were observed in extravascular spaces.These observations represent a valuable step towards understanding sequestration patterns of P. falciparum gametocytes and may ultimately lead to novel transmission-blocking interventions.

View Article: PubMed Central - HTML - PubMed

Affiliation: Laboratoire de parasitologie-mycologie, Assistance publique hôpitaux de Paris, Groupe Hospitalier Pitié-Salpêtrière, 47 Boulevard de l'Hôpital, 75651 Paris Cedex 13, France.

ABSTRACT

Background: Plasmodium falciparum immature gametocytes accumulate in the bone marrow, but their exact location in this tissue remains unclear.

Methods: The stage and deposition pattern of gametocytes was analysed on histological sections of a bone marrow sample collected in a patient with subacute P. falciparum malaria.

Results: A majority (89%) of immature stages II to IV gametocytes and a minority (29%) of mature stage V gametocytes were observed in extravascular spaces.

Discussion and conclusion: These observations represent a valuable step towards understanding sequestration patterns of P. falciparum gametocytes and may ultimately lead to novel transmission-blocking interventions.

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Related in: MedlinePlus

Gametocyte staging on Giemsa-stained smears (cytology, reference method) and on HES-stained sections (histology) from the same bone marrow biopsy sample described in this report. Leaf-shaped forms, hemi-ellipsoid forms, forms with at least one sharp extremity, and crescent forms with two rounded extremities, a concave and a convex border were counted as stage II, III, IV and V, respectively (columns II-V). A form with finely distributed pigment, but not falling into any of the previous categories, was categorized as undetermined stage (column U). Counting results appear on Table 1.
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Figure 1: Gametocyte staging on Giemsa-stained smears (cytology, reference method) and on HES-stained sections (histology) from the same bone marrow biopsy sample described in this report. Leaf-shaped forms, hemi-ellipsoid forms, forms with at least one sharp extremity, and crescent forms with two rounded extremities, a concave and a convex border were counted as stage II, III, IV and V, respectively (columns II-V). A form with finely distributed pigment, but not falling into any of the previous categories, was categorized as undetermined stage (column U). Counting results appear on Table 1.

Mentions: Stained histological sections of the bone marrow showed gametocytes at different maturation stages and numerous macrophages containing blood cells or malaria pigment. Gametocytes were readily identified and staged based on their oval or elongated shape and finely distributed pigment (Figure 1). Only 29% (4/14) of stage V gametocytes were in extravascular spaces (Table 1), the majority being in intravascular spaces (Figure 2C). By contrast, 89% (87/98) of immature stage II-IV gametocytes were observed in extravascular spaces (Table 1, Figure 2) in immediate contact with erythroblasts (Figure 2B), adipocytes (Figure 2A) or other nucleated cells (Figure 2B). Several gametocytes did not co-localize with CD34-positive vascular structures (Figure 2D) or CD68-positive cells (Figure 2E).


The extravascular compartment of the bone marrow: a niche for Plasmodium falciparum gametocyte maturation?

Farfour E, Charlotte F, Settegrana C, Miyara M, Buffet P - Malar. J. (2012)

Gametocyte staging on Giemsa-stained smears (cytology, reference method) and on HES-stained sections (histology) from the same bone marrow biopsy sample described in this report. Leaf-shaped forms, hemi-ellipsoid forms, forms with at least one sharp extremity, and crescent forms with two rounded extremities, a concave and a convex border were counted as stage II, III, IV and V, respectively (columns II-V). A form with finely distributed pigment, but not falling into any of the previous categories, was categorized as undetermined stage (column U). Counting results appear on Table 1.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3472181&req=5

Figure 1: Gametocyte staging on Giemsa-stained smears (cytology, reference method) and on HES-stained sections (histology) from the same bone marrow biopsy sample described in this report. Leaf-shaped forms, hemi-ellipsoid forms, forms with at least one sharp extremity, and crescent forms with two rounded extremities, a concave and a convex border were counted as stage II, III, IV and V, respectively (columns II-V). A form with finely distributed pigment, but not falling into any of the previous categories, was categorized as undetermined stage (column U). Counting results appear on Table 1.
Mentions: Stained histological sections of the bone marrow showed gametocytes at different maturation stages and numerous macrophages containing blood cells or malaria pigment. Gametocytes were readily identified and staged based on their oval or elongated shape and finely distributed pigment (Figure 1). Only 29% (4/14) of stage V gametocytes were in extravascular spaces (Table 1), the majority being in intravascular spaces (Figure 2C). By contrast, 89% (87/98) of immature stage II-IV gametocytes were observed in extravascular spaces (Table 1, Figure 2) in immediate contact with erythroblasts (Figure 2B), adipocytes (Figure 2A) or other nucleated cells (Figure 2B). Several gametocytes did not co-localize with CD34-positive vascular structures (Figure 2D) or CD68-positive cells (Figure 2E).

Bottom Line: Plasmodium falciparum immature gametocytes accumulate in the bone marrow, but their exact location in this tissue remains unclear.A majority (89%) of immature stages II to IV gametocytes and a minority (29%) of mature stage V gametocytes were observed in extravascular spaces.These observations represent a valuable step towards understanding sequestration patterns of P. falciparum gametocytes and may ultimately lead to novel transmission-blocking interventions.

View Article: PubMed Central - HTML - PubMed

Affiliation: Laboratoire de parasitologie-mycologie, Assistance publique hôpitaux de Paris, Groupe Hospitalier Pitié-Salpêtrière, 47 Boulevard de l'Hôpital, 75651 Paris Cedex 13, France.

ABSTRACT

Background: Plasmodium falciparum immature gametocytes accumulate in the bone marrow, but their exact location in this tissue remains unclear.

Methods: The stage and deposition pattern of gametocytes was analysed on histological sections of a bone marrow sample collected in a patient with subacute P. falciparum malaria.

Results: A majority (89%) of immature stages II to IV gametocytes and a minority (29%) of mature stage V gametocytes were observed in extravascular spaces.

Discussion and conclusion: These observations represent a valuable step towards understanding sequestration patterns of P. falciparum gametocytes and may ultimately lead to novel transmission-blocking interventions.

Show MeSH
Related in: MedlinePlus