Urinary early kidney injury molecules in children with beta-thalassemia major

Figures & data

Table 1. Demographic and biochemical characteristics of the patients and the control group.

	Thalassemia Group (n = 52)	Controls (n = 29)	p
Age, years	9.1 ± 4.4 (8.0; 3.0–17.0)	8.8 ± 4.0 (8.0; 3.0–17.0)	NS
Height, cm	124.2 ± 22.9 (128.0; 75.0–159.0)	125.5 ± 20.3 (122.0; 92.0–159.0)	NS
Weight, kg	30.3 ± 12.2 (28.0; 10.0–60.0)	29.6 ± 13.5 (25.0; 13.0–56.0)	NS
Serum glucose (mg/dL)	93.5 ± 13.4 (92.5; 64.0–134.0)	95.2 ± 10.5 (95.0; 76.0–110.0)	NS
Serum urea (mg/dL)	26.9 ± 7.2 (26.5; 8.0–40.0)	27.3 ± 7.9 (21.0; 8.0–36.0)	NS
Serum creatinine (mg/dL)	0.47 ± 0.10 (0.46; 0.30–0.80)	0.50 ± 0.08 (0.50; 0.38–0.70)	NS
eGFR (ml/min/1.73 m^2)	121 ± 29 (119; 71–189)	116 ± 18 (120; 92–157)	NS
Serum sodium (mEq/L)	137.3 ± 2.5 (137.0; 131.0–143.0)	137.7 ± 2.1 (138.0; 134.0–142.0)	NS
Serum potassium (mEq/L)	4.2 ± 0.28 (4.2; 3.6–5.1)	4.1 ± 0.42 (4.0; 3.5–5.1)	NS
Serum calcium (mg/dL)	9.3 ± 0.5 (9.4; 8.2–10.2)	9.4 ± 0.62 (9.4; 8.5–10.5)	NS
Serum phosphate (mg/dL)	3.5 ± 0.6 (3.5; 2.5–4.9)	3.4 ± 0.5 (3.5; 2.5–4.3)	NS

Notes: Data presented are [mean, (median; minimum-maximum)]; eGFR, estimated glomerular filtration rate; NS: Not significant.

Table 2. Hematological characteristics of β-TM children and healthy controls [mean, (median; minimum–maximum)].

	Thalassemia group (n = 52)	Control group (n = 29)	p
Hemoglobin (g/100 mL)	8.2 ± 1.5 (8.5; 5.1–11.5)	11.8 ± 1.1 (11.5; 10.7–14.1)	<0.001
Hematocrit (%)	23.7 ± 4.7 (23.5; 12.9–33.6)	36.7 ± 3.3 (36.1; 30.8–44.1)	<0.001
RBC (×10^6 cells/µL)	3.19 ± 0.76 (3.12; 1.65–5.20)	4.79 ± 0.40 (4.78; 4.12–5.36)	<0.001
Platelet count (×10^3 cells/µL)	390 ± 208 (349; 115–1235)	308 ± 95 (346; 149–429)	NS
Ferritin (ng/mL)	2552 ± 1413 (1988; 859–6826)	78 ± 33 (82; 19–143)	<0.001

Notes: β-TM, β-thalassemia major; RBC: Red blood count; NS: Not significant.

Table 3. Urinary electrolytes, uric acid, and protein–creatinine ratios of the patients and the controls [mean, (median; minimum–maximum)].

	Thalassemia (n = 52)	Controls (n = 29)	p
UNa/Cr	2.28 ± 1.85 (2.13; 0.27–11.88)	1.97 ± 1.08 (1.78; 0.17–4.51)	NS
UK/Cr	1.11 ± 0.72 (0.97; 0.07–4.00)	0.94 ± 0.58 (0.84; 0.30–3.04)	NS
UCa/Cr	0.12 ± 0.04 (0.12; 0.02–0.42)	0.11 ± 0.09 (0.06; 0.02–0.21)	NS
UP/Cr	0.58 ± 0.36 (0.46; 0.12–1.42)	0.69 ± 0.41 (0.63; 0.12–1.77)	NS
UMg/Cr	0.13 ± 0.04 (0.12; 0.05–0.25)	0.13 ± 0.06 (0.12; 0.04–0.25)	NS
UProtein/Cr	0.13 ± 0.09 (0.10; 0.04–0.47)	0.07 ± 0.04 (0.06; 0.03–0.20)	<0.001
UUric acid/Cr	0.55 ± 0.29 (0.50; 0.10–1.42)	0.44 ± 0.29 (0.32; 0.13–1.12)	NS

Notes: U, Urinary; Cr, Creatinine; Na, Sodium; K, Potassium; Ca, Calcium; P, Phosphorus; Mg, Magnesium; NS, Not significant.

Table 4. Urinary novel early biomarkers–creatinine ratios of the β-thalassemia major and the control groups [mean, (median; minimum–maximum)].

	Thalassemia group (n = 52)	Controls (n = 29)	p
UNAG/Cr	0.48 ± 0.58 (0.28; 0.09–2.85)	0.23 ± 0.16 (0.19; 0.04–0.61)	0.026
UNGAL/Cr	22.1 ± 18.5 (14.4; 5.8–91.0)	11.5 ± 6.17 (10.7; 0.92–22.8)	0.010
UKİM1/Cr	0.062 ± 0.049 (0.045; 0.01–0.23)	0.044 ± 0.018 (0.036; 0.02–0.08)	NS
UL-FABP/Cr	0.133 ± 0.105 (0.102; 0.030–0.460)	0.126 ± 0.080 (0.119; 0.030–0.350)	NS

Notes: U_NAG/Cr, urinary N-acetyl-beta-d-glucosaminidase to creatinine; U_NGAL/Cr, urinary neutrophil gelatinase associated lipocalin to creatinine; U_KIM-1/Cr, urinary kidney injury molecule-1 to creatinine; U_L-FABP/Cr, urinary liver-type fatty acid binding protein to creatinine; NS, Not significant.

Table 5. Spearman’s correlation coefficients in β-thalassemia major group of urinary novel early biomarkers with other variables.

Variables		UNAG/Cr	UNGAL/Cr	UKIM-1/Cr	UL-FABP/Cr
UNAG/Cr	r		0.772	0.809	0.707
	p		<0.001	<0.001	<0.001
UNGAL/Cr	r			0.882	0.716
	p			<0.001	<0.001
UKIM-1/Cr	r				0.751
	p				<0.001
UK/Cr	r	NS	0.316	0.318	NS
	p		0.039	0.031
UCa/Cr	r	0.606	0.558	0.612	0.528
	p	<0.001	<0.001	<0.001	<0.001
UNa/Cr	r	0.409	0.338	0.434	0.364
	p	0.008	0.027	0.003	0.018
UUric acid/Cr	r	0.412	0.423	0.418	0.310
	p	0.007	0.005	0.004	0.046

Notes: U_NAG/Cr, urinary N-acetyl-beta-d-glucosaminidase to creatinine; U_NGAL/Cr, urinary neutrophil gelatinase associated lipocalin to creatinine; U_KIM-1/Cr; urinary kidney injury molecule-1 to creatinine; U_L-FABP/Cr, urinary liver-type fatty acid binding protein to creatinine; NS, Not significant.