Expression of mast cell tryptase and immunoglobulin E is increased in cutaneous photodamage: implications for carcinogenesis

Figures & data

Figure 1. Immunohistochemical staining for (A) mast cell tryptase and (B) IgE on skin sections from the forearm sun-exposed skin. Note that there are several IgE⁺ cells with cell membrane-like circular staining (B). The micrographs were taken using a 40× objective.

Table 1. The numbers of tryptase⁺ and IgE⁺ cells in the photodamaged forearm and sun-protected upper arm skin.

	Tryptase^+cells/mm	IgE^+cells/mm²	Correlation between IgE^+ and tryptase^+ cells
All subjects
Upper arm (sun-protected)	N = 385 43.2 ± 23.4	N = 380 33.1 ± 17.0	0.932
Forearm (sun-exposed)	N = 385 51.4 ± 28.2	N = 380 39.4 ± 21.1	0.960
p Value	<.001	<.001	Upper arm <.001 Forearm <.001
Immunocompetent subjects
Upper arm	N = 310 44.1 ± 23.5	N = 306 33.9 ± 17.0	0.928
Forearm	N = 310 52.1 ± 29.1	N = 306 40.1 ± 21.7	0.958
p Value	<.001	<.001	Upper arm <.001 Forearm <.001
Immunosuppressed subjects
Upper arm	N = 7539.8 ± 22.6	N = 7430.1 ± 16.4	0.943
Forearm	N = 7548.5 ± 23.8	N = 7436.4 ± 17.8	0.966
p Value	.006	<.001	Upper arm <.001 Forearm <.001

Notes: The p values were calculated with paired samples t-test. The results have been presented with a mean ± standard deviation. The correlation was calculated with the Spearman correlation test. Significant p values have been marked in bold.

Table 2. Spearman correlation between the forearm/upper arm ratio of tryptase⁺ and IgE⁺ cells and different variables.

	Forearm/upper arm cell ratio				Forearm cells/mm²
	Tryptase (N = 385)		IgE (N = 380)		Tryptase (N = 385)		IgE (N = 380)
Variable	Correlation coefficient	p Value	Correlation coefficient	p Value	Correlation coefficient	p Value	Correlation coefficient	p Value
Age (years) N = 385	0.075	.143	0.103	.045	0.050	.332	0.098	.056
Gender N = 385	0.000	1.000	0.015	.775	0.046	.366	0.024	.643
BMI (kg/m²) N = 383	−0.048	.353	−0.068	.187	−0.109	.033	−0.093	.071
Immunosuppression N = 385	0.045	.380	0.039	.450	−0.030	.559	−0.054	.288
Fitzpatrick skin type N = 357	−0.043	.419	−0.093	.080	0.046	.384	0.020	.703
Fitzpatrick points N = 354	−0.015	.774	−0.044	.408	0.035	.512	0.008	.878
Alcohol usage N = 373	−0.025	.633	−0.034	.520	−0.076	.141	−0.062	.234
Indoor tanning N = 381	0.006	.911	0.005	.927	−0.013	.803	−0.002	.965
UV-light treatment N = 365	0.083	.113	0.079	.137	0.035	.505	0.031	.562
Lifetime sun exposure N = 378	−0.068	.185	−0.069	.183	−0.074	.152	−0.067	.193
Work related sun exposure N = 379	−0.026	.617	−0.023	.657	0.016	.752	0.020	.702
Lifetime sunburns N = 381	−0.026	.616	−0.029	.578	−0.050	.332	−0.050	.335
Tobacco pack years N = 365	0.046	.379	0.044	.400	0.069	.191	0.083	.114
PAASI-score N = 383	0.087	.089	0.088	.089	0.063	.218	0.081	.115
Facial photoaging score N = 384	0.069	.178	0.105	.041	0.034	.504	0.084	.101
Forearm photoaging score N = 384	0.082	.109	0.079	.126	0.092	.072	0.115	.025
Skin cancer risk class N = 385	−0.003	.953	0.024	.638	0.010	.846	0.036	.483
AK count N = 384	0.073	.152	0.083	.108	0.038	.456	0.085	.099
Mole count N = 382	−0.026	.617	−0.031	.549	0.076	.139	0.054	.295
Skin tumor count N = 384	0.073	.155	0.071	.168	0.100	.051	0.101	.049
Leukocyte count N = 381	0.066	.200	0.087	.092	−0.044	.387	−0.028	.589
Neutrophil count N = 374	0.042	.419	0.050	.336	−0.065	.209	−0.058	.261
Eosinophil count N = 371	0.016	.764	0.007	.894	0.031	.548	0.082	.116
Monocyte count N = 373	0.067	.199	0.101	.052	0.020	.696	0.044	.401
Lymphocyte count N = 373	0.030	.562	0.077	.142	0.026	.615	0.039	.453
Thrombocyte count N = 381	0.047	.356	0.060	.249	0.058	.257	0.058	.258
Hb N = 381	−0.013	.797	−0.012	.821	−0.030	.560	−0.026	.614

Note: Significant p values have been marked in bold.

Table 3. The logistic regression analysis and consequent odds ratios for subjects with a photodamage score 2–4 (N = 208) compared to control subjects with a score 0–1 (N = 176) in the forearm skin in all subjects.

Variable	Missing values (number)	Univariate odds ratio	95% confidence interval	p Value	Multivariate odds ratio	95% confidence interval	p Value
Age  <Median 66  ≥Median 66	0	Ref.,17.139	4.544–11.216	<.001	7.051	4.187–11.874	<.001
Gender  Male  Female	0	Ref.,10.665	0.944–0.996	.048	1.072	0.604–1.906	.811
BMI	2	1.011	0.972–1.053	.580	1.006	0.956–1.059	.818
Immunosuppression  No  Yes	0	Ref.,10.602	0.362–1.000	.050	0.635	0.337–1.197	.161
Indoor tanning  Never  30 times  31–100 times	4	Ref.,10.792 0.594	0.486–1.292 0.242–1.456	.351 .255	1.173 1.225	0.616–2.234 0.404–3.715	.627 .719
Lifetime sun exposure  Rarely  Occasionally  Often  Very often	7	Ref.,11.135 1.192 0.831	0.695–1.997 0.661–2.149 0.417–1.656	.661 .559 .598	1.919 1.349 1.055	0.943–3.904 0.634–2.869 0.422–2.635	.072 .437 .909
Work related sun exposure  Outdoor  Indoor  Mixed  Outdoor/indoor	6	Ref.,10.382 0.597	0.170–0.858 0.250–1.429	.020 .247	0.497 0.808	0.188–1.312 0.294–2.221	.158 .680
Lifetime sunburns  Seldom  Occasionally  Often	4	Ref.,10.676 0.780	0.432–1.181 0.444–1.371	.102 .388	0.799 0.824	0.445–1.433 0.388–1.751	.451 .615
Any smoking history  No  Yes	5	Ref.,11.685	1.119–2.537	.012	1.253	0.738–2.127	.403
Skin cancer risk class  Mild  Moderate  High	0	Ref.,11.800 3.203	1.129–2.869 1.733–5.920	.013 <.001	1.192 1.598	0.664–2.139 0.943–4.232	.556 .071
Tryptase cells/mm^2 Upper arm	0	1.002	0.994–1.011	.611	0.985	0.946–1.025	.443
Tryptase cells/mm^2 Forearm	0	1.009	1.001–1.016	.024	1.027	0.975–1.081	.316
IgE cells/mm^2 Upper arm	0	1.006	0.994–1.018	.332	1.024	0.964–1.089	.440
IgE cells/mm^2 Forearm	0	1.014	1.004–1.024	.007	0.976	0.976–0.908	.500
IgE/tryptase ratio Forearm	0	2.613	0.858–7.957	.091	2.418	0.397–14.721	.338
Forearm/upper arm ratio of tryptase	0	1.044	0.916–1.190	.520	0.862	0.657–1.131	.283
Forearm/upper arm ratio of IgE	0	1.210	0.951–1.540	.121	1.234	0.564–2.698	.599

Notes: Significant p values have been marked in bold. Photodamage score: 0 = no, 1 = mild, 2 = moderate, 3 = severe with actinic keratosis, 4 = very severe with actinic keratoses.

Table 4. Comparison of tryptase⁺ and IgE⁺ cells between atopic and non-atopic subjects.

Variables	Non-atopy			Atopy			Atopy vs. non-atopy Upper arm	Atopy vs. non-atopy Forearm
	Upper arm	Forearm	p Value	Upper arm	Forearm	p Value	p Value	p Value
All subjects
Tryptase^+ mast cells/mm²	N = 243 44.5 ± 24.0	N = 243 54.1 ± 30.1	<.001	N = 134 41.4 ± 22.7	N = 13447.7 ± 24.1	.004	.216	.034
IgE^+ mast cells/mm²	N = 240 33.6 ± 17.2	N = 240 41.0 ± 22.8	<.001	N = 132 33.0 ± 16.8	N = 132 37.2 ± 17.6	.008	.745	.108
IgE/tryptase	N = 240 0.8 ± 0.3	N = 240 0.8 ± 0.2	.574	N = 132 0.9 ± 0.3	N = 132 0.8 ± 0.2	.085	.107	.331
Immunocompetent subjects
Tryptase^+ mast cells/mm²	N = 195 45.2 ± 24.4	N = 195 54.4 ± 31.7	<.001	N = 110 42.2 ± 22.3	N = 110 48.9 ± 24.0	.007	.329	.088
IgE^+ mast cells/mm²	N = 193 34.0 ± 17.5	N = 193 41.4 ± 23.8	<.001	N = 108 34.0 ± 16.6	N = 108 38.3 ± 17.7	.017	.996	.232
IgE/tryptase	N = 193 0.8 ± 0.3	N = 193 0.8 ± 0.2	.513	N = 108 0.9 ± 0.2	N = 108 0.8 ± 0.2	.114	.308	.380
Immunosuppressed subjects
Tryptase^+ mast cells/mm²	N = 48 42.0 ± 21.7	N = 48 52.8 ± 22.9	.017	N = 24 37.7 ± 24.6	N = 24 42.0 ± 24.0	.329	.378	.068
IgE^+ mast cells/mm²	N = 47 31.7 ± 16.0	N = 47 39.3 ± 18.1	.018	N = 24 28.6 ± 17.5	N = 24 32.3 ± 16.6	.225	.398	.097
IgE/tryptase	N = 47 0.8 ± 0.2	N = 47 0.8 ± 0.2	.887	N = 24 0.9 ± 0.6	N = 24 0.8 ± 0.1	.390	.154	.722

Notes: The p values were calculated with paired samples t-test in atopy and non-atopy subgroups. The comparison between atopic and non-atopic subjects was made with independent samples t-test. The results have been presented with mean ± SD (standard deviation). Significant values have been marked in bold.

Data availability statement

The research data is available from the corresponding author upon separate request.