Chemokine CCL18 predicts intraventricular hemorrhage in very preterm infants

Figures & data

Table I. Characteristics of the study group (n = 163).

Variable
HCA^a	64 (40.3)^b
Antenatal steroid^a	140 (85.9)
Vaginal delivery^a	47 (28.8)
Gestational age (week)^c	29.1 (23.3–31.9)
Birth-weight (g)^c	1170 (370–2295)
ELGAN^a	49 (30.1)
Male^a	85 (52.1)
RDS^a	105 (64.4)
PDA^a	44 (27.0)
IVH
Grade I^a	45 (27.6)
Grade II^a	10 (6.1)
Grade III^a	8 (4.9)
Grade IV^a	5 (3.1)
Early IVH (n = 160)
Grade I^a	18 (11.0)
Grade II^a	7 (4.3)
Grade III^a	1 (0.6)
Grade IV^a	4 (2.5)

^aData are given as frequency; n (%).

^bA total number of placentas examined (n = 159), 4 missing cases.

^cData are given as median (minimum–maximum).

ELGAN = extremely low gestational age new-born; HCA = histologic chorioamnionitis; IVH = intraventricular hemorrhage; PDA = patent ductus arteriosus; RDS = respiratory distress syndrome.

Table II. Differences of clinical factors in univariate analyses between two outcome groups.

Factor	IVH grade II–IV (n=23)	No IVH or IVH grade I (n=140)	P-value^a
HCA^b	13 (56.5)	51 (37.5)	0.085^c
Funisitis^b	6 (26.1)	27 (19.9)	0.495^c
Pre-eclampsia^13	5 (21.7)	37 (26.4)	0.634^c
Antenatal steroid^b	18 (78.3)	122 (87.1)	0.257^c
Vaginal delivery^b	9 (39.1)	38 (27.1)	0.240^c
GA (wk)^d	27.7 (25.1–28.9)	29.6 (27.9–30.9)	<0.0001^e
SGA^b	4 (17.4)	34 (24.3)	0.600^f
5 min Apgar score^d	6 (5–7)	7 (6–8)	0.023^e
First 12 h, CRIB score^d	9.00 (3–11)	2 (1–5)	<0.0001^e
First 24 h, lowest mean BP (mmHg)^d	21 (16–24)	27 (23–31)	<0.0001^e
First 24 h, highest paCO2 (kPa)^d	6.5 (5.7–7.6)	6.1 (5.2–7.1)	0.117^e
RDS^b	23 (100)	82 (58.6)	<0.0001^f
PDA^b	15 (65.2)	29 (20.7)	<0.0001^c
CCL18 (FU)^d	4060 (3078–5866)	6471 (4796–7670)	0.002^e

^aP < 0.05 was considered as significant.

^bData are given as frequency; n (%).

^cPearson chi-square test.

^dData are given as median (25th–75th percentiles).

^eMann-Whitney U test.

^fFisher's exact test.

BP = blood pressure; CCL18 = chemokine (C-C motif) ligand 18; CRIB = clinical risk index for babies; FU = fluorescence units; GA=gestational age; HCA = histologic chorioamnionitis; IVH = intraventricular hemorrhage; PDA=patent ductus arteriosus; RDS = respiratory distress syndrome; SGA = small for gestational age.

Figure 1. Receiver operating characteristic (ROC) curve showing the cord blood concentration of CCL18 in prediction of the risk of intraventricular hemorrhage grade II–IV. Low level of CCL18 in cord blood (cut-off value 4969 fluorescence units) predicted IVH in very preterm infants with a sensitivity of 74% and a specificity of 73% (area under ROC curve 0.72, P=0.002).

Table III. A multiple logistic regression model shows independent risk factors of IVH grade II–IV.

Predictor	Odds ratio (95% confidence interval)	P-value^a
CCL18	7.7 (2.2–27.0)	0.001
Low mean BP	4.6 (1.3–16.5)	0.019

Covariates: CCL18 < 4969 FU, gestational age < 28 weeks, 5 min Apgar score < 7, clinical risk index for babies > 4, lowest mean blood pressure (BP) < 25 mmHg, respiratory distress syndrome, patent ductus arteriosus.

^aP < 0.05 was considered as significant.

Table IV. A multiple logistic regression model shows independent risk factors of early IVH grade II–IV.

Predictor	Odds ratio (95% confidence interval)	P-value^a
CCL18	14.5 (2.4–88.2)	0.004
GM-CSF	7.7 (1.4–41.2)	0.017
Low mean BP	11.2 (1.8–70.5)	0.01

Covariates: CCL18 < 4969 FU, GM-CSF < 596 FU, IL-8 > 5847 FU, gestational age < 28 week, histologic chorioamnionitis, 5 min Apgar score < 7, clinical risk index for babies score > 4, lowest mean blood pressure (BP) < 25 mmHg, respiratory distress syndrome, patent ductus arteriosus.

^aP < 0.05 was considered as significant.

Table V. Analysis of plasma concentrations of CCL18 (pg/mL) from very preterm infants with IVH grade II–IV and no IVH or IVH grade I using enzyme-linked immunosorbent assay.

	IVH grade II-IV			No IVH or IVH grade I
Postnatal age	Mean (SD)	Median	n	Mean (SD)	Median	n	P value^a
Day 0, cord blood	4177 (860)	4181	12	6011 (1866)	5684	11	0.01
Day 1	7957 (2160)	7670	12	9751 (2918)	10292	11	0.077
Day 7	10645 (10525)	7072	12	13176 (10525)	10964	11	0.123

Both in the IVH grade II–IV group and no IVH or IVH grade I groups, CCL18 concentrations increased from day 0 to day 1 (P < 0.05, paired t test).

^at test (equal variances not assumed).

Figure 2. Immunohistochemical localization of CCR3 in the brain. Representative brain samples from preterm (A–F) and term (G–J) infants from different gestational weeks as indicated were stained with anti-CCR3 antibodies. Panel A shows the positive staining in the germinal matrix. Big black arrows indicate the staining in the ependymal cells, small black arrows in the endothelium of the capillaries, small open arrows in the neurons of the hippocampus, and big open arrows in the choroid plexus. Panels G and H represent samples from an infant with long-term asphyxia with remarkable capillary proliferation and an intense CCR3 staining of the endothelia. Panels I and J represent samples from an infant who died from an acute asphyxia. Original magnification in all figures is ×200.