3.1. Demographic and serum S100B/cytokines levels of GAD cases and HC
We analyzed the data of 108 GAD cases and 123 HC. There was no significant difference in the male/female ratio and age between GAD subjects and HC.
The baseline serum S100B and IL-1β, IL-2 levels of GAD cases were lower than HC significantly (P<0.001), the serum IL-4 levels of GAD cases were higher than HC (P<0.001), while IL-10 had no significant difference between two groups (P=0.215)(see Table 1 ).
The correlation of serum S100B and IL-1β, IL-2, IL-4, IL-10 levels in GAD cases with age was (r = -0.065, P = 0.505), (r = -0.147, P = 0.128), (r = -0.056, P = 0.568),(r = 0.013, P = 0.893), (r = -0.113, P = 0.244) respectively.
Table 1. Demographic and clinical characteristics of GAD and HC
Characteristics
|
GAD (n = 108)
|
HC (n = 123)
|
Statistics
|
χ2/t
|
P value
|
Sex (male/female)
|
30/78
|
40/83
|
0.612
|
0.434
|
Age (years)
|
49.6 ± 11.3
|
47.5 ± 8.4
|
1.567
|
0.119
|
HAMA scores
|
22.5±3.1
|
NA
|
|
|
HAMD scores
|
9.6 ± 2.9
|
NA
|
|
|
Illness duration(month)
|
24.4±37.5
|
NA
|
|
|
S100B(pg/ml)
|
330.3 ± 79.9
|
421.8 ± 123.0
|
6.785
|
<0.001
|
IL-1β(pg/ml)
|
35.5 ± 11.3
|
56.1 ± 15.0
|
11.883
|
<0.001
|
IL-2(pg/ml)
|
34.7 ± 8.7
|
57.0 ± 16.3
|
13.214
|
<0.001
|
IL-4(pg/ml)
|
63.7 ± 21.4
|
46.7 ± 10.6
|
7.474
|
<0.001
|
IL-10(pg/ml)
|
42.6 ± 9.4
|
41.0 ± 10.6
|
1.242
|
0.215
|
GAD:generalized anxiety disorder, HC:healthy controls, HAMA: Hamilton Anxiety Rating Scale, HAMD: Hamilton Depression Rating Scale
3.2. The single diagnosis value of S100B, IL-1β, IL-2, IL-4, IL-10 in GAD
3.2.1 The ROC value of S100B, IL-1β, IL-2, IL-4, IL-10 in GAD
The ROC area of S100B, IL-1β, IL-2 and IL-4 in diagnosis of GAD was (0.740 ± 0.032) , (0.900 ± 0.021) , (0.920 ± 0.018) and (0.696 ± 0.037) , all of them suggested a good predicting value (P < 0.001) , while the ROC area of IL-10 was (0.544 ± 0.038) (P = 0.251). (see Figure 1,2)
3.2.2 The sensitivity, specificity, Yorden index and Kappa value of S100B , IL-1β and IL-2 in the diagnosis of GAD
Based on the ROC curve, the sensitivity, specificity, Yorden index and Kappa value of S100B and IL-1β, IL-2 were calculated, define 375pg/ml, 41pg/ml and 43pg/ml as cut point of S100B, IL-1β and IL-2 respectively, the sensitivity and specificity of IL-1β and IL-2 were all above 80%, the details of sensitivity, specificity, Yorden index and Kappa value of S100B , IL-1β and IL-2 see Table 2, all of these indexes suggested a good diagnosis value (P < 0.001).
Table 2 The sensitivity, specificity, Yorden index and Kappa value of S100B , IL-1β and IL-2
|
Sensitivity(%)
|
Specificity(%)
|
Yorden index
|
Kappa value
|
S100B
|
73.1
|
61.0
|
0.341
|
0.338
|
IL-1β
|
80.6
|
86.2
|
0.668
|
0.669
|
IL-2
|
85.2
|
80.5
|
0.657
|
0.653
|
3.3 The combination diagnosis value of S100B and IL-1β, IL-2, IL-4 in GAD
Based on the single diagnosis value of S100B, IL-1β, IL-2, IL-4, IL-10, S100B, IL-1β, IL-2 and IL-4 were included in the combination diagnosis of GAD. The combination ROC area of S100B, IL-1β , IL-2 and IL-4 was (0.985 ± 0.006), the combination ROC area of S100B, IL-2 and IL-4 was (0.983 ± 0.006), the combination ROC area of S100B, IL-1β and IL-2 was (0.945 ± 0.014), the combination ROC area of S100B, IL-1β and IL-4 was (0.940 ± 0.015). The combination ROC of IL-2 and IL-4 was (0.974 ± 0.009), the combination ROC of IL-1β and IL-2 was (0.940 ± 0.015), the combination ROC of S100B and IL-2 was (0.932 ± 0.017), the combination ROC of IL-1β and IL-4 was (0.926 ± 0.018), the combination ROC of S100B and IL-1β was (0.913 ± 0.020), all of them suggested a good predicting value (P < 0.001) .(see Figure 3)
3.4 Relationship between serum S100B and cytokines (IL-1β, IL-2, IL-2, IL-10) and clinical features (HAMA scores, illness duration)
The serum S100B and IL-1β, IL-2, IL-4, IL-10 was (330.3±79.9), (35.5±11.3), (34.7±8.7), (63.7±21.4), (42.6±9.4) respectively, the correlation between serum S100B and IL-1β, IL-2, IL-4, IL-10 was (r = 0.175, P = 0.070), (r = 0.237, P = 0.014), (r = 0.261, P = 0.006),(r = 0.055, P = 0.589) respectively.
The serum S100B and HAMA scores, illness duration was (330.3 ±79.9), (22.5±3.1), (24.4±37.5), respectively, the correlation between serum S100B and HAMA scores, illness duration was (r = -.386, P <0.001),(r = 0.080, P = 0.410) respectively.