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. Author manuscript; available in PMC: 2014 Sep 26.
Published in final edited form as: Sci Transl Med. 2014 Jul 9;6(244):244re5. doi: 10.1126/scitranslmed.3008882

Fig. 1. Enrichment of developing gametocytes in the human bone marrow.

Fig. 1

(A) Detection of parasites and gametocytes across tissues. Parasite antigens (pLDH for all parasites and Pfs16 for gametocytes) were visualized with alkaline phosphatase and Fast Red substrate, and nuclei were labeled with blue hematoxylin stain. Shown are representative images of Pfs16-labeled gametocytes in the spleen, bone marrow, and brain, and of multiple pLDH-labeled sequestering parasites in the brain microvasculature. (B and C) Quantification of parasite and gametocyte load across tissues. Numbers of pLDH-positive (left axis) and Pfs16-positive (right axis) parasites were quantified per 100 high-power fields (hpf) for each organ for 6 or 10 patients (those marked with +). Dots indicate the parasite load (one dot per patient), with bars for mean and SD across patients. Gametocyte fractions (C) were calculated as a ratio of Pfs16-positive parasites to pLDH-positive parasites in 100 high-power fields from each sample, for each tissue in which at least 10 pLDH parasites were observed. Dots indicate gametocyte fraction in each patient, with bars for median and interquartile range across patients. Asterisk above graph indicates significant difference by Fisher’s exact test using categories of <33% and >33% gametocyte fraction and comparing the top five organs. (D) Distribution of time to death compared with gametocyte fraction. The time (hours) from admission to death for all patients from which the bone marrow gametocyte fraction was calculated in this study, plotted by those cases with gametocyte fractions below and above 33%. (E) Gametocyte-stage distribution across tissues by qRT-PCR. Transcript copy number for early developing (stage I/II, PF14_0748), mid developing (stage III/IV, Pfs4845), and late developing and mature gametocytes (stage IV/V, Pfs25) and the constitutive marker PF08_0085 in tissue homogenates, normalized by RNA input. RNA from five organs was analyzed from five patients. Dots indicate transcript copy number in each patient, with bars for mean and SE. (F) Summary of the autopsy cases and experimental methods used in this study. IHC, immunohistochemistry.