Dynamics of lymphocyte subsets in children living in an area polluted by polychlorinated biphenyls

Figures & data

Table 1  Characteristics of study cohort consisting of 362 mother-infant pairs in two districts, Michalovce (n = 301) and Svidnik/Stropkov (n = 61).

	Michalovce		Svidnik/Stropkov		Total
	n	%	n	%	n	%
Maternal age
≤ 19	18	4.9	5	1.3	23	6.3
20–29	213	58.8	42	11.6	255	70.4
≥ 30	70	19.3	14	3.8	84	23.2
Sex of child
Male	149	41.1	32	8.8	181	50.0
Female	152	41.9	29	8.0	181	50.0
Ethnicity
Slovakian/other Eastern European	246	67.9	51	14.0	297	82.0
Romani	55	15.1	10	2.7	65	17.9
Maternal smoking
No	234	64.6	56	15.4	290	80.1
Yes	56	15.4	5	1.3	61	16.8
Missing	11	3.03	0	0	11	3.0
Parity
0	131	36.1	30	8.2	161	44.4
1	92	25.4	15	4.1	107	29.5
2	56	15.4	10	2.7	66	18.2
3	16	4.4	6	1.6	22	6.0
4	5	1.3	0	0	5	1.3
Missing	1	0.2	0	0	1	0.2
Breastfeeding
Yes	281	77.6	58	16.0	339	93.6
No	15	4.1	0	0	15	4.1
Missing	5	1.3	3	0.8	8	2.2

n = number of participants.

Table 2  The maternal and birth characteristics of the study group.

Variable	Mean	SD	Median	Minimum	Maximum
Gestational age (weeks)	39.68	1.21	40.00	33.00	42.00
Maternal age (years)	26.19	5.01	26.00	18.00	43.00
Birth weight (grams)	3314.80	506.35	3340.00	1660.00	4740.00

Table 3  Total main lymphocyte subpopulations in cord, 6- and 16-months blood samples from Michalovce and Svidnik/Stropkov districts.

	Major lymphocyte sub-populations
	Cord blood				6-month-old children				16-month-old children
	Mean	Median	5^th Percentile	95^th Percentile	Mean	Median	5^th Percentile	95^th Percentile	Mean	Median	5^th Percentile	95^th Percentile
CD3^+ T-lymphocytes	61.7	63.3	37.3	79.8	64.5	64.7	51.0	76.5	64.3	65.5	48.3	76.1
CD4^+ T-lymphocytes	45.2	45.8	26.3	62.2	43.9	43	31.5	57.5	40.8	41.2	25.2	54.5
CD8^+ T-lymphocytes	14.2	14.0	5.8	24.4	17.5	17.1	8.9	28.0	18.6	18.4	9.9	28.5
CD19^+ B-lymphocytes	16.6	15.4	7.7	28.9	27.4	27.4	12.0	39.9	26.3	26.0	15.3	40.5
CD3^−CD(56 + 16)^+ NK cells	12.0	8.9	2.8	35.1	6.2	5.0	1.3	16.3	6.7	4.7	1.4	22.1
HLADR^+CD19^+ activated cells	16.2	15.2	7.1	28.4	27.2	27.4	15.2	40.4	26.1	25.6	11.8	39.5

Table 4  CD marker correlation between samples of blood from children in the total study cohort.

	CB « 6M	6M « 16M	16M « CB
CD19^+, B-lymphocytes	0.285**	0.390**	0.186**
HLADR^+CD19^+, Activated B-lymphocytes	0.281**	0.380**	0.184**
CD3^−CD(56 + 16)^+, Natural Killer cells	0.203**	0.261**	0.098*
CD3^+, CD3^+ T-lymphocytes	0.180**	0.348**	0.197**
CD3^+CD8^+, CD8^+ T-lymphocytes	0.229**	0.363**	0.215**
CD3^+CD4^+, CD4^+ T-lymphocytes	0.251**	0.352**	0.233**

* p < 0.05; ** p < 0.01.

CB, cord blood; 6M, 6-month-old child; 16M, 16-month-old child.

Figure 1  Dynamics of the lymphocyte subsets in children in the Svidnik/Stropkov and Michalovce regions. The immunophenotyping was performed by multi-color analysis of blood samples collected form children at birth (cord blood), and again at 6- and 16-months-of-age. Populations of CD3⁺, CD3⁺CD4⁺, and CD3⁺CD8⁺ T-lymphocytes, CD19⁺ B-lymphocytes, HLADR⁺CD19⁺ activated B-lymphocytes, and CD3⁻CD(56 + 16)⁺ NK cells in each sample were analyzed. Flow cytometric analysis was performed on a Cytomics FC 500 (Beckman Coulter). Statistical analysis was performed using an SPSS System. p-Values reflect comparisons made to cord blood levels. Data shown are as mean of percentage (± SEM).

Table 5  Coefficients and standard errors in models predicting immunophenotyping markers in samples of blood from children from Michalovce and Svidnik/Stropkov.

	Models predicting percentage of:
	CD19^+			CD3^+			CD4^+			CD8^+			CD3^−CD(16 + 56)^+			HLADR^+CD19^+
	B	SE	Sig.	B	SE	Sig.	B	SE	Sig.	B	SE	Sig.	B	SE	Sig.	B	SE	Sig.
Cord blood
District
Svidnik/Stropkov	2.485	1.016	p < 0.050	2.033	2.093	0.332	−0.360	1.836	0.845	2.820	0.890	p < 0.010	−5.727	1.576	p < 0.001	2.491	1.019	p < 0.050
vs Michalovce
Gender: F vs M	−0.100	0.689	0.895	−0.401	1.400	0.775	−1.080	1.228	0.380	1.405	0.595	p < 0.050	−0.434	1.054	0.681	−0.071	0.682	0.917
Parity	1.168	0.780	0.135	−5.880	1.587	p < 0.001	−4.271	1.393	p < 0.010	−2.052	0.675	p < 0.010	4.128	1.196	p < 0.001	1.366	0.776	0.079
Age of mother	0.102	0.069	0.143	0.107	0.140	0.446	0.102	0.123	0.409	0.054	0.060	0.365	−0.085	0.106	0.423	0.139	0.068	p < 0.050
Season
Spring vs summer	−1.184	0.868	0.174	3.593	1.761	p < 0.050	3.381	1.545	p < 0.050	−0.152	0.749	0.840	−1.922	1.327	0.148	−1.119	0.858	0.193
Summer vs autumn	0.451	0.899	0.617	2.227	1.839	0.227	1.674	1.613	0.300	−0.146	0.782	0.852	−1.779	1.385	0.200	0.745	0.895	0.406
Summer vs winter	0.510	1.214	0.675	1.220	2.458	0.620	1.410	2.156	0.514	−0.948	1.046	0.365	−1.229	1.851	0.507	0.466	1.202	0.698
6-month-old children
District
Svidnik/Stropkov	2.549	1.128	p < 0.050	−0.095	1.145	0.934	−0.982	1.212	0.418	0.966	0.827	0.244	−3.267	0.723	p < 0.001	2.811	1.137	p < 0.050
vs Michalovce
Gender: F vs M	1.101	0.836	0.189	−0.935	0.841	0.267	−2.017	0.890	p < 0.050	0.777	0.607	0.202	−0.137	0.531	0.797	0.841	0.835	0.315
Birth weight	−0.002	0.001	p < 0.050	0.003	0.001	p < 0.001	0.003	0.001	p < 0.001	0.000	0.001	0.507	−0.001	0.001	0.207	−0.002	0.001	p < 0.050
Mother education
HS vs HSG	0.597	0.899	0.507	−1.809	0.905	p < 0.050	−0.602	0.958	0.530	−0.931	0.653	0.155	0.209	0.572	0.715	0.604	0.895	0.500
Pregnancy smoke
Non vs smokers	−1.811	1.194	0.130	1.261	1.202	0.295	0.221	1.272	0.862	1.007	0.868	0.247	−0.219	0.759	0.773	−1.866	1.198	0.120
Breast feeding	−0.684	2.005	0.733	−0.122	2.036	0.952	1.381	2.156	0.522	−1.537	1.471	0.297	0.821	1.287	0.524	−0.783	2.024	0.699
16-month-old children
District
Svidnik/Stropkov	3.971	1.229	p < 0.001	3.859	1.310	p < 0.010	1.031	1.367	0.452	1.395	0.905	0.124	−6.396	0.993	p < 0.001	3.803	1.196	p < 0.010
vs Michalovce
Gender: F vs M	−0.365	0.896	0.684	0.029	0.944	0.975	−1.754	0.986	0.076	1.800	0.653	p < 0.010	−0.160	0.716	0.823	−0.464	0.862	0.591
Birth weight	0.000	0.001	0.727	0.001	0.001	0.231	0.002	0.001	0.056	−0.001	0.001	0.135	0.000	0.001	0.626	0.000	0.001	0.970
Mother education
HS vs HSG	1.542	0.962	0.110	−2.117	1.011	p < 0.050	−3.020	1.055	p < 0.010	1.194	0.700	0.089	0.468	0.767	0.542	1.683	0.923	0.069
Pregnancy smoke
Non vs smokers	−2.723	1.269	p < 0.050	0.373	1.337	0.780	−1.088	1.395	0.436	1.736	0.924	0.061	1.334	1.014	0.189	−2.308	1.220	0.060
Breast feeding	−3.026	2.089	0.149	0.155	2.232	0.945	2.841	2.330	0.224	−2.425	1.542	0.117	0.493	1.693	0.771	−2.997	2.038	0.142

SE, standard error; B, coefficients; HSG, high school with graduation; HS, high school without graduation.