Genetic variation in interleukin-7 is associated with a reduced erythropoietic response in Kenyan children infected with Plasmodium falciparum

Table 1 Demographic, clinical, and laboratory characteristics of the study participants

Characteristic	UM ( n = 718)	SMA (n = 165)	P-value
Sex
Male, n (%)	356 (49.6)	79 (47.7)	0.72 ^a
Female, n (%)	362 (50.4)	86 (52.3)	0.72 ^a
Age (months)	12.2 (7.3–18.4)	10.0 (6.3–16.7)	0.01 ^b
Axillary temperature (°C)	37.6 (36.8–38.1)	38.0 (37.0–38.4)	<0.02 ^b
Hemoglobin (g/dL)	7.8 (6.2–9.1)	4.3 (3.7–4.7)	<0.01 ^b
RBC count (× 10¹²/μL)	3.7 (2.8–4.5)	2.9 (2.2–4.1)	<0.01 ^b
RDW	20.3 (18.1–23.0)	20.7 (18.0–23.3)	0.48^b
MCHC	30.7 (29.6–32.3)	30.6 (29.5–32.3)	0.79 ^b
RPI	0.5 (0.3–1.1)	0.5 (0.29–0.98)	0.42^b
RPI <2.0, n (%)	605 (89.5)	136 (94.4)	0.07 ^a
WBC count (× 10³/μL)	11.9 (9.0–15.9)	12.7 (9.5–17.0)	0.08 ^b
Parasite density (per μL)	30,424.6 (7163.1-91,570.0)	24,180.0 (4605.7-71,849.7)	0.03 ^b
HDP (≥10,000 parasites/μL)	506 (70.7)	106 (64.2)	0.11
α-thalassemia, n (%)	130 (21.0)	24 (17.1)	0.42 ^a
G6PD deficiency, n (%)	25 (4.0)	5 (3.5)	0.45^a
Sickle cell trait, n (%)	102 (14.9)	21 (14.1)	0.62 ^a

^aData are median (interquartile range, IQR) or n (%). UM [uncomplicated malaria, non-severe malarial anemia (Hb ≥5.0 g/dL)] and SMA [severe malarial anemia (Hb<5.0 g/dL)]; both with any density parasitemia. RBC red blood cell, RDW red cell distribution width, MCHC mean corpuscular hemoglobin concentration, WBC white blood cell and HDP high density parasitemia. The reticulocyte production index (RPI) was calculated as follows: RPI=reticulocyte index (RI)/maturation factor (MF), where RI=(reticulocyte count [%] x hematocrit [Hct]/0.36) and MF=b+(m)(x), where b=1, m=0.05, and x=(average normal population Hct - patient’s Hct) [27]; α-thalassemia data are for homozygous individuals (α^-3.7); G6PD, glucose-6-phosphate dehydrogenase deficiency (G6PD)
^aStatistical significance was determined by Chi-square analysis
^bStatistical significance determined by Mann–Whitney U test. P-values ≤0.050 were considered significant, and are indicated in bold. n=Number

ISSN: 1471-2350