The role of anaemia in oxidative and genotoxic damage in transfused β-thalassaemic patients

Figures & data

Table 1. Biochemical and haematological parameters, blood and iron intake per year, cardiac and hepatic MRIT2* in the patient cohort.

	Mean ± SD	Minimum–Maximum	Confidence −95.0%	Confidence +95.0%	Skewness	Kurtosis	p Shapiro–Wilk
Serum ferritin, ng/ml	1217.9 ± 1350.8	73.0–6882.2	898.1	1537.6	2.19	5.16	0.00
Serum iron, µg/dl	244.8 ± 64.5	89.0–424.0	229.5	260.1	0.30	0.55	0.37
Transferrin, mg/dl	174.4 ± 41.9	110.1–339.0	164.2	184.6	1.83	4.87	0.00
%TSAT^a	101.5 ± 24.8	44.0–158.0	95.4	107.5	−0.09	−0.27	0.76
Pre-transfusion Hb, g/dl	9.90 ± 0.65	8.10–11.10	9.74	10.05	−0.50	−0.26	0.04
CRP, mg/l	4.76 ± 7.75	0.10–52.00	2.84	6.68	4.40	22.77	0.00
ESR, mm	20.15 ± 16.40	2.0–89.0	15.38	24.91	1.78	5.34	0.00
Reticulocytes, %	2.81 ± 4.84	0.00–28.20	1.34	4.28	3.83	17.82	0.00
Cardiac MRI T2^b, ms	27.36 ± 12.82	5.00–53.00	23.90	30.83	−0.21	−1.00	0.04
Hepatic MRI T2^c, ms	11.11 ± 8.70	0.70–33.00	8.75	13.46	0.73	−0.28	0.00
Total RBCs transfused, ml/kg/year	130.9 ± 28.6	70.3–202.2	124.0	137.8	0.22	−0.29	0.41
Iron intake, mg/kg/year	141.4 ± 30.9	75.9–218.4	133.9	148.8	0.22	−0.29	0.41

^a%TSAT was calculated according: http://www.emocromatosi.it/test.asp.

^bCardiac iron overload was defined by MRI T2*global values as: mild (14–20 ms), moderate (10–14 ms) or severe (<10 ms).

^cHepatic iron overload was defined by MRI T2* values as: mild (6.3–2.7 ms), moderate (2.6–1.4 ms) or severe (<1.4 ms).

Figure 1. Results of bivariate analysis by Mann–Whitney test to compare lymphocytic oxidative damage and genotoxic effect in patient cohort and health controls. (a) ROS as assessed in function of DCF emission values (p = 0.0001). (b) 8-oxo-dG as assessed in function of emission values of Avidin-FITC emission values (p < 0.0001). (c) Oxidative DNA damage to Comet assay evaluated by %TDNA (p = 0.01). (d) MNi frequency (p = 0.027). (e) NDI used as markers of proliferative activity (p = 0.001).

Table 2. Oxidative and genotoxic damage in patients grouped according the levels of Hb (g/dl).

Variables	Hb < 10 Retic. % 2.8 (1.7–6.9) N°51	Hb ≥10 Retic. % 0.42 (0.2–1.3) N°54	p
ROS	38.7 (19.6–63.3)	24.0 (16.8–54.6)	0.018
8-oxo-dG	34.3 (19.6–45.9)	26.6 (19.4–38.1)	0.042
MNi	21.0 (13.0–26.0)	13 (8–16)	0.0005
MNed	20 (13–24)	13 (9–17)	0.0008
NDI	2.0 (1.7–2.2)	2.28 (1.9–2.5)	0.026
Apoptotic + Necrotic cells	42 (31–56)	34 (21–43)	0.038
TDNA%	18.0 (10.3–29.7)	8.3 (5.8–10.0)	0.001

The values are reported as median and in the brackets is reported the interquartile interval.

Table 3. Multiple regression analysis for oxidative and genotoxic effects.

Covariates	ROS	8-Oxi-dG	MNi	NDI	Necrotic and apoptotic cells	TDNA%25th	TDNA%50th	TDNA%75th
^a	0.348 (0.047)	0.402 (0.046)	0.381 (0.005)	0.419 (0.001)	0.494 (0.045)	0.688 (0.0003)	0.368 (0.007)	0.317 (0.024)
Age					0.516 (0.003)
Hb	−0.468 (0.045)	−0.457 (0.048)	−0.533 (0.001)	0.328 (0.03)		−0.371 (0.01)	−0.337 (0.036)	−0.449 (0.045)
Ferritin
Serum iron					0.358 (0.041)
Cardiac siderosis					−0.350 (0.047)
Hepatic siderosis				−0.296 (0.041)	−0.383 (0.043)

For each covariate are reported β value and, in the bracket, p value.

^aR² adjusted obtained by a priori model.