Patients’ baseline characteristics
A total of 60 patients were included in the study. 20 in the STS BID (treatment) group, 20 in the STS QD (treatment) group and 40 in the control group. The baseline characteristics of the patients, including age, sex, and IGA/EASI/SCORAD score at baseline, which were similar among the three groups (p >0.05) (Table 1).
Table 1 Demographic and clinical characteristics of the AD patients at baseline
Group
|
ST group
|
STS QD group
|
STS BID group
|
P
|
Number
|
20
|
20
|
20
|
|
Age
|
53.9 ± 11.3
|
44.8 ± 19.0
|
50.6 ± 17.9
|
0.552
|
Gender
|
|
|
|
-
|
Female
|
12 (60.0%)
|
14 (70.0%)
|
16 (80.0%)
|
|
Male
|
8 (40.0%)
|
6 (30.0%)
|
4 (20.0%)
|
|
IGA score
at baseline
|
|
|
|
0.284
|
2
|
2 (10.0%)
|
1 (5.0%)
|
0 (0.0%)
|
|
3
|
7 (35.0%)
|
4 (20.0%)
|
3 (15.0%)
|
|
4
|
11 (55.0%)
|
15 (75.0%)
|
17 (85.0%)
|
|
Abbreviations: AD, atopic dermatitis; EASI, Eczema Area and Severity Index; IGA, Investigator’s Global Assessment; SCORAD, Scoring of Atopic Dermatitis index.
Efficacy
The primary endpoint was assessed in our patients (Figure 1B). The proportion of patients receiving STSQD plus the standard of care who achieved EASI-50 and EASI75 after 1 week of treatment was significantly higher than the proportion in the control group who achieved EASI-50 (P =.025) and EASI75 (P=.037). However, the proportion of patients who achieved EASI50 and EASI75 with the STS BID group plus the standard of care was similar to that observed in the group that received 0.64 g of STS plus the standard of care (P =.028 of EASI50, P=.029 of EASI75). We also evaluated the time required to attain itching relief in each group as another criterion of efficacy. The results showed that the length of time required for itching relief to occur in the STSBID group (3.50±0.688) were significantly shorter than those in the STSQD group (4.90±1.119) and control group (5.595±1.731) (p<0.05) (Figure 1A), which suggests that STS may improve the efficacy of AD and shorten the course of treatment. In relevance to the change in the clinical severity of AD, the reduced values of the EASI and SCORAD scores were recorded. The mean SCORAD indices at baseline were 52.66±10.21 for the control group, 56.62±10.55 for the STSQD group and 53.71±10.34 for the STSBID group (Table 1). There was no statistically significant difference among the three groups (P>0.05). Comparing the mean SCORAD indices between the three groups at the date of discharge, the STSQD group exhibited a reduction of approximately 8.8±3.43, and the STSBID group exhibited a decrease of approximately 15.71±4.78 compared to the control group, with a reduction of 30.4±9.47 (P<0.05) (Figure 1C). The mean SCORAD indices were significantly lower in the STS group than in the control group. Similarly, the EASI score shows the same tendency. The EASI score at baseline in the three groups was 13.83±1.74 (control group), 14.11±1.75 (STS QD group), and 13.72±1.57 (STS BID group) (Table 1). The difference was not statistically significant. At the date of discharge, the STS BID group index was 4.43±1.84, with 7.88±2.07 in the STS QD group and 10.19±1.34 in the control group (Figure 1 D).
Clinical responses in biomarker concentrations
STS treatment was associated with significantly lower total IgE, eosinophil, IL-13, and IL-4 concentrations in the peripheral blood at the end of treatment than at baseline. At baseline, there was no significant difference in the mean concentration of total IgE between the three groups, with values of 1628.0±397.84 IU/mL in the STS BID group, 1571.2±267.613 IU/mL in the STS QD group and 1583.0±302.75 in the control group. Similarly, the mean blood eosinophil count at baseline was not significantly different, with 1.33±0.76 cells/μL in the STSBID group, 1.39±0.74 in the STSQD group and 1.35±0.66 cells/μL in the control group. At the date of discharge, we found that STS downregulated IgE and eosinophils significantly more than the control treatment. The mean concentration of total IgE was 656.20±388.281 IU/mL in the STSBID group, 998.80±264.468 IU/mL in the STSQD group and 1379.30±330.194 in the control group (P<0.05) (Figure 2A). The mean blood eosinophil count was 0.19±0.15/µL in the STSBID group, 0.89±0.59 in the STSQD group, and 1.18±0.73/µL in the control group (P<0.05) (Figure 2B). The data of IL-4 and IL-13 in the peripheral blood of each group before and after treatment were also collected, and the results showed that both cytokines presented an abnormal increasing trend in the AD patients of each group, and there was no statistically significant difference at baseline among the three groups (35.21±2.84 for control group vs. 34.62±2.91 for STS QD group vs. 35.09±2.09). After treatment, the reduction in IL-13 and IL-4 showed the same pattern as IgE and eosinophils. At the date of discharge, the concentrations of IL-13 in the STSBID group was 21.43±2.10, compared to 26.13±2.62 in the STSQD group and 30.25±2.80 in the control group (P<0.05) (Figure 2C). Similarly, STSBID downregulated IL-4 to 5.53±1.79, compared to 10.45±1.91 in the STSQD group and 30.25±2.80 in the control group (P<0.05) (Figure 2D).