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Table 4 Loss of infected erythrocytes as a percentage of total erythrocyte loss, in participants inoculated with Pf3D7, PfK13 and P. vivax

From: Haematological response in experimental human Plasmodium falciparum and Plasmodium vivax malaria

Pf all (n = 267) Median (IQR) Pf 3D7 (n = 254)
Median (IQR)
Pf K13 (n = 15)
Median (IQR)
P. vivax (n = 46)
Median (IQR)
P-value
(3D7 vs K13) d
P-value
(Pf all vs P. vivax) d
Baseline RCC (× 1012/L) 5.0
(4.7–5.8)
5.0
(4.7–5.8)
5.1
(4.6–5.2)
5.0
(4.7–5.2)
0.58 0.57
Nadir RCC (× 1012/L) 4.5
(4.2–4.8)
4.5
(4.2–4.8)
4.4
(3.8–4.6)
4.4
(4.0–4.8)
0.07 0.31
Total RCC Loss (× 1012/L) 0.5
(0.3–0.7)
0.5
(0.3–0.6)
0.7
(0.6–0.8)
0.5
(0.4–0.6)
0.0005 0.57
Malaria-attributable RCC loss (× 1012/L) a 0.21
(0.04–0.36)
0.20
(0.04–0.33)
0.34
(0.12–0.50)
0.21
(0.04–0.33)
0.06 0.87
Malaria-attributable RCC loss/total RCC loss (%) b 42
(13–51)
40
(13–55)
49
(20–63)
42
(13–55)
0.29 0.46
Loss of pRBC/total malaria-attributable RBC loss (%) c 0.015
(0.006–0.060)
0.014
(0.005–0.039)
0.128
(0.068–0.616)
0.022
(0.008–0.082)
 < 0.0001 0.19
  1. n number of participants; IQR interquartile range
  2. aCalculated by subtracting the estimated phlebotomy-related RBC loss from the total RBC loss. For this calculation, the phlebotomy-related RBC loss was estimated by multiplying the participant’s baseline RCC (× 1012/L) by the estimated total phlebotomy blood volume (0.19L) from day of inoculation to the median day of haemoglobin nadir; bThe percentage contribution of the malaria-attributable erythrocytes losses from the total erythrocyte losses was determined by dividing the malaria-attributable losses by the erythrocyte losses and multiplying by 100 to generate a percentage; cThe loss of pRBCs was equal to the TPBPre, which was determined using the AUC of the 18S qPCR data from day 4 until the time of treatment. For P. falciparum, the TPBPre incorporated an adjustment to account for parasite sequestration, assumed to be an assumed approximately 25% at any given timepoint. This calculation assumed that each erythrocyte was singly infected, and that parasite replication did not continue following treatment; dMann–Whitney test of significance, not adjusted for multiple comparisons