The impact of vitamin D deficiency on immune T cells in asthmatic children: a case-control study

Figures & data

Table 1 Patients’ characteristics

Characteristic	Data
Number of subjects	39
Sex
Male	(68.4%)
Body weight (kg)	32.7 (26–45)
Age	9.8 (6–16)
Positive skin tests results	68.4%
FVC (%)	88.38 (58–112)
FEV1 (%)	92.74 (53–120)
FEV1/FVC	0.9 (0.79–1)
Passive smoking	47.3%
Severity
Mild persistent	60.5%
Moderate persistent	36.8%
Severe persistent	2.7%

Abbreviations: FEV₁, forced expiratory volume in 1 second; FVC, forced vital capacity.

Table 2 Comparison of vitamin D levels in asthmatic patients and controls

Vitamin D levels	Patients	Controls
Deficient (<20 ng/mL)	17	0
Insufficient (20–29 ng/mL)	16	6
Sufficient (≥30 ng/mL)	6	24

Notes: Fisher test, P = 0.000; Chi squared test for linear trend = 30.303, P = 0.000.

Figure 1 Vitamin D concentrations of asthmatic patients.

Notes: Box and whiskers plots of vitamin D concentrations of normal controls (n = 30) and asthmatic patients (n = 39). The medians are indicated by a line inside each box, the 25th and 75th percentiles are indicated by the box limits, and the lower and upper error bars represent the 10th and 90th percentiles, respectively. The mean values were compared and the P values are indicated in the figure. Moderate asthmatics expressed lower vitamin D levels than mild asthmatics did. Mann–Whitney rank sum tests assessed the difference between mild and moderate asthmatic patients.

Figure 2 Correlation between vitamin D level and serum IL-6 (A) and serum IL-17 (B) using, Pearson’s correlation coefficient.

Notes: Significant positive correlation was observed for serum IL-17 level (r = 0.617; P = 0.0001). No correlation was found between serum IL-6 vitamin D levels (r = 0.068; P = 0.677).
Abbreviation: IL, interleukin.

Figure 3 Intracellular Th1 and Th2 cytokines. (A–D) Box and whiskers plot of (A) percentage of interferon-gamma (IFN-γ) producing cells; (B) percentage of IL-4 producing cells; and (C) the ratio of Th1/Th2 cytokine (interferon-gamma [IFN-γ] and IL-4) determined by Fast Immune Cytokine System for normal controls (n = 30) and asthmatic patients (n = 39). The medians are indicated by a line inside each box, the 25th and 75th percentiles are indicated by the box limits, and the lower and upper error bars represent the 10th and 90th percentiles, respectively. The mean values were compared and the P values are indicated at the figure. (D) Correlation between Th1/Th2 ratio and vitamin D levels in asthmatic patients using Pearson’s correlation coefficient.

Note: Mann–Whitney rank sum test assessed the differences between controls and patients.
Abbreviation: IL, interleukin.

Figure 4 Intracellular Type 1 regulatory T (Tr1) cells (IL-10) and Th17 (IL-17) cytokines CD4⁺ production.

Notes: Box and whiskers plot of Tr1-producing cells/Th17-producing cells ratio in asthmatic patients and healthy children. Tr1 and Th17 cytokine were determined by fast immune cytokine system from normal controls (n = 30) and asthmatic patients (n = 39). The medians are indicated by a line inside each box, the 25th and 75th percentiles are indicated by the box limits, and the lower and upper error bars represent the 10th and 90th percentiles, respectively. The mean values were compared and the P values are indicated.

Figure 5 CD25⁺Foxp3⁺ Treg in the CD4⁺ T cell compartment. Box and whiskers plot of percentage of CD25⁺Foxp3⁺ Treg in the CD4⁺ T cells (A). The medians are indicated by a line inside each box, the 25th and 75th percentiles are indicated by the box limits, and the lower and upper error bars represent the 10th and 90th percentiles, respectively. Correlation between CD25⁺Foxp3⁺ Treg cells and vitamin D levels in asthmatic patients using Pearson’s correlation coefficient (B).

Note: Mann–Whitney rank sum test assessed the differences between controls and patients.