Study on the Relationship Between Bronchoalveolar Lavage Fluid Cell Count, Th1/Th2 Cytokines and Pulmonary Function in Patients with Cough Variant Asthma

Figures & data

Table 1 Baseline Table: Comparison of Three Groups of Basic Information

	Total Number of Cases (n=132)	Cough Group (n=36)	CA Group (n=39)	CVA Group (n=57)	P value
Gender					0.656
Male	54 (39.39)	15 (41.67)	18 (46.15)	21 (36.84)
Female	78 (59.01)	21 (58.33)	21 (53.85)	36 (63.16)
Age	40 (33, 52)	35 (32.5, 41.0)	39 (35.5, 51.00)	36.5 (31, 51.75)	0.491
IgE (IU/mL)	41.62 (16.52, 128.26)	15.14 (12.42, 35.77)	214 (55.67, 359.44)	33.84 (10.92, 126.70)	0.000
FEV1 (L)	2.66 (2.05, 3.20)	3.44 (2.47, 4.32)	1.87 (1.39, 2.87)	2.94 (2.64, 3.12)	0.000
FVC (L)	3.06 (2.64, 3.79)	3.89 (2.76, 5.15)	2.25 (2.03, 4.09)	3.48 (2.98, 3.72)	0.000
FEV1/FVC	1.02 (0.97, 1.06)	1.06 (1.02, 1.08)	0.89 (0.76, 1.02)	1.01 (0.99, 1.04)	0.000
FeNO (ppb)	21.50 (15.75, 39.00)	22 (16.00, 32.00)	40 (21.00, 45.50)	17 (12, 30.50)	0.000

Notes: Data are expressed as number of cases (percentage) or M (P25, P75). The differences between the three groups were compared using the chi-square test or Kruskal–Wallis test.

Abbreviations: CA, classical asthma; CVA, cough variant asthma; IgE, immunoglobulin E; FVC, forced vital capacity; FEV1, forced expiratory volume in 1s; FeNO, fractional exhaled nitric oxide; ppb, parts per billion.

Figure 1 Hematoxylin-eosin (HE) staining results of cell count in bronchoalveolar lavage fluid (A) H&E stained images of BALF specimens from patients with cough variant asthma (CVA), chronic cough and classical asthma (CA); (B) the number of macrophage counts, neutrophils, lymphocytes and eosinophils in BALF specimens, differences between the three groups were compared using Kruskal–Wallis test. ***P<0.001 is considered a significant difference compared to the chronic cough group, and ###P<0.001 shows a significant difference compared to the CA group.

Figure 2 Th1 cytokine interferon-γ (IFN-γ) and Th2 cytokines interleukin 4 (IL-4), IL-5, IL-13, IL-18, and IL-25 in bronchoalveolar lavage fluid measured by enzyme-linked immunosorbent assay (ELISA) from cough variant asthma (CVA), chronic cough and classical asthma (CA) patients. Differences between the three groups were compared using the Kruskal–Wallis test. **P<0.01, ***P<0.001 shows a significant difference compared to the chronic cough group, and #P<0.05, ##P<0.01 shows a significant difference compared to the typical asthma group.

Table 2 Relationship Between Cell Count and Pulmonary Function

	Macrophages		Lymphocytes		Neutrophils		Eosinophil
	R	P	R	P	R	P	R	P
IgE	−0.187	0.032	0.219	0.012	0.193	0.026	0.086	0.326
FEV1	0.247	0.004	−0.218	0.012	−0.259	0.003	−0.263	0.002
FVC	0.183	0.036	−0.164	0.061	−0.194	0.026	−0.207	0.017
FEV1/ FVC	0.238	0.006	−0.203	0.020	−0.268	0.002	−0.191	0.028
FeNO	−0.255	0.015	0.261	0.013	0.311	0.003	0.311	0.003

Notes: The correlation analysis between two variables was performed using Spearman correlation analysis, and P < 0.05 was considered as correlation between the two variables. The correlation coefficient R represents the strength of the correlation and takes values in the range of [−1, +1], the closer to −1 or +1, the stronger the correlation. A negative number represents a negative correlation, a positive number represents a positive correlation, and 0 means no correlation exists.

Abbreviations: IgE, immunoglobulin E; FVC, forced vital capacity; FEV1, forced expiratory volume in 1s; FeNO, fractional exhaled nitric oxide; ppb, parts per billion.

Table 3 Relationship Between Cytokines and Pulmonary Function

	IL-18		IFN-γ		IL-4		IL-5		IL-13		IL-25
	R	P	R	P	R	P	R	P	R	P	R	P
IgE	0.202	0.020	−0.176	0.044	0.189	0.030	0.211	0.015	0.195	0.025	0.167	0.056
FEV1	−0.256	0.003	0.237	0.006	−0.261	0.002	−0.282	0.001	−0.251	0.004	−0.232	0.007
FVC	−0.196	0.025	0.180	0.039	−0.201	0.021	−0.222	0.010	−0.196	0.024	−0.175	0.045
FEV1/ FVC	−0.269	0.002	0.262	0.002	−0.277	0.001	−0.262	0.002	−0.272	0.002	−0.253	0.003
FeNO	0.339	0.001	−0.334	0.001	0.336	0.001	0.335	0.001	0.308	0.003	0.340	0.001

Notes: The correlation analysis between two variables was performed using Spearman correlation analysis, and P < 0.05 was considered as correlation between the two variables. The correlation coefficient R represents the strength of the correlation and takes values in the range of [−1, +1], the closer to −1 or +1, the stronger the correlation. A negative number represents a negative correlation, a positive number represents a positive correlation, and 0 means no correlation exists.

Abbreviations: IgE, immunoglobulin E; FVC, forced vital capacity; FEV1, forced expiratory volume in 1s; FeNO, fractional exhaled nitric oxide; ppb, parts per billion.