Correlation analysis of depressive symptoms and immune function indicators in patients with malignant melanoma

Table 1 Comparison of patient baseline characteristics, n (%)/mean ± SD

Characteristic	Total (n = 202)	Non-depression group (n = 89)	Depression group (n = 113)	χ2/t value	P value
Demographic characteristics
Age (years)	57.3 ± 13.8	55.8 ± 14.2	58.4 ± 13.5	-1.32	0.188
Gender
Male	117 (57.9)	49 (55.1)	68 (60.2)	0.68	0.410
Female	85 (42.1)	40 (44.9)	45 (39.8)
Education level
Middle school and below	76 (37.6)	27 (30.3)	49 (43.4)	8.42	0.038
High school/technical school	89 (44.1)	42 (47.2)	47 (41.6)
College and above	37 (18.3)	20 (22.5)	17 (15.0)
Marital status
Married	154 (76.2)	72 (80.9)	82 (72.6)	2.15	0.143
Single/divorced/widowed	48 (23.8)	17 (19.1)	31 (27.4)
Employment status
Employed	98 (48.5)	50 (56.2)	48 (42.5)	6.78	0.034
Retired	67 (33.2)	28 (31.5)	39 (34.5)
Unemployed/jobless	37 (18.3)	11 (12.4)	26 (23.0)
Disease characteristics
Pathological type
Superficial spreading	126 (62.4)	59 (66.3)	67 (59.3)	4.89	0.180
Nodular	51 (25.2)	19 (21.3)	32 (28.3)
Acral lentiginous	18 (8.9)	8 (9.0)	10 (8.8)
Others	7 (3.5)	3 (3.4)	4 (3.5)
TNM stage
Stage I	45 (22.3)	26 (29.2)	19 (16.8)	7.89	0.048
Stage II	78 (38.6)	36 (40.4)	42 (37.2)
Stage III	58 (28.7)	21 (23.6)	37 (32.7)
Stage IV	21 (10.4)	6 (6.7)	15 (13.3)
Breslow thickness (mm)	3.8 ± 2.6	3.2 ± 2.3	4.3 ± 2.8	-2.86	0.005
Ulceration
Present	89 (44.1)	32 (36.0)	57 (50.4)	4.92	0.027
Absent	113 (55.9)	57 (64.0)	56 (49.6)
Lymph node metastasis
Present	79 (39.1)	27 (30.3)	52 (46.0)	8.95	0.003
Absent	123 (60.9)	62 (69.7)	61 (54.0)
General condition
BMI (kg/m2)	23.7 ± 4.2	24.1 ± 3.8	23.4 ± 4.5	1.12	0.264
ECOG score
0 points	78 (38.6)	43 (48.3)	35 (31.0)	12.86	0.002
1 point	89 (44.1)	38 (42.7)	51 (45.1)
2 points	35 (17.3)	8 (9.0)	27 (23.9)
Comorbidities
Hypertension	68 (33.7)	26 (29.2)	42 (37.2)	3.68	0.159
Diabetes	32 (15.8)	12 (13.5)	20 (17.7)
Coronary heart disease	21 (10.4)	7 (7.9)	14 (12.4)
Others	15 (7.4)	6 (6.7)	9 (8.0)
None	66 (32.7)	38 (42.7)	28 (24.8)

TNM: Tumor-node-metastasis; BMI: Body mass index; ECOG: Eastern Cooperative Oncology Group.

Table 2 Comparison of Depressive Symptom Assessment Scale total scores, mean ± SD

Scale	Total (n = 202)	Non-depression group (n = 89)	Depression group (n = 113)	Z/t value	P value
PHQ-9 total score [M (Q1, Q3)]	7.0 (3.0, 12.0)	2.0 (1.0, 4.0)	11.0 (8.0, 15.0)	-12.84	< 0.001
PSQI total score [M (Q1, Q3)]	8.5 (5.0, 12.0)	6.0 (4.0, 8.0)	11.0 (8.0, 14.0)	-8.67	< 0.001
FSS total score	4.2 ± 1.8	3.1 ± 1.4	5.1 ± 1.6	-9.15	< 0.001
PSS-10 total score	18.6 ± 7.3	14.2 ± 5.8	22.1 ± 6.9	-8.42	< 0.001

PHQ-9: Patient Health Questionnaire-9; PSQI: Pittsburgh Sleep Quality Index; FSS: Fatigue Severity Scale; PSS: Perceived Stress Scale.

Table 3 Comparison of cellular immune indicators, mean ± SD

Indicator	Non-depression group (n = 89)	Depression group (n = 113)	t/Z value	P value
CD3+ cell count (cells/μL)	1486 ± 428	1267 ± 396	3.68	< 0.001
CD3+ cell percentage (%)	68.2 ± 9.8	64.7 ± 11.2	2.31	0.022
CD4+ cell count (cells/μL)	894 ± 287	736 ± 253	4.02	< 0.001
CD4+ cell percentage (%)	40.8 ± 7.6	37.2 ± 8.4	3.14	0.002
CD8+ cell count (cells/μL)	542 ± 198	486 ± 176	2.09	0.038
CD8+ cell percentage (%)	24.7 ± 6.2	25.8 ± 7.1	-1.15	0.252
CD4+/CD8+ ratio	1.72 ± 0.48	1.51 ± 0.52	2.94	0.004
NK cell count (cells/μL)	387 ± 142	325 ± 128	3.24	0.001
NK cell percentage (%)	17.8 ± 6.4	15.2 ± 5.9	2.98	0.003
B cell count (cells/μL)	248 ± 89	221 ± 76	2.27	0.024
B cell percentage (%)	11.3 ± 4.2	10.6 ± 3.8	1.23	0.220

NK: Natural killer.

Table 4 Comparison of humoral immune indicators, mean ± SD

Indicator	Non-depression group (n = 89)	Depression group (n = 113)	t value	P value
IgG (g/L)	12.8 ± 3.2	11.9 ± 3.6	1.83	0.069
IgA (g/L)	2.4 ± 0.8	2.2 ± 0.9	1.65	0.101
IgM (g/L)	1.3 ± 0.4	1.2 ± 0.5	1.48	0.141
Complement C3 (g/L)	1.18 ± 0.26	1.09 ± 0.31	2.18	0.030
Complement C4 (g/L)	0.28 ± 0.09	0.25 ± 0.08	2.41	0.017

IgG: Immunoglobulin G; IgA: Immunoglobulin A; IgM: Immunoglobulin M.

Table 5 Comparison of inflammatory and immune-related cytokines, mean ± SD

Indicator	Non-depression group (n = 89)	Depression group (n = 113)	t/Z value	P value
IL-6 (pg/mL), M (Q1, Q3)	4.2 (2.8, 7.1)	8.6 (5.3, 14.2)	-6.74	< 0.001
TNF-α (pg/mL), M (Q1, Q3)	12.4 (8.7, 18.3)	19.8 (14.2, 28.6)	-5.89	< 0.001
IL-10 (pg/mL)	8.3 ± 3.6	6.7 ± 3.2	3.26	0.001
IFN-γ (pg/mL)	15.8 ± 7.2	12.4 ± 6.8	3.42	0.001
CRP (mg/L), M (Q1, Q3)	5.8 (2.1, 12.4)	12.7 (6.8, 23.5)	-4.96	< 0.001
ESR (mm/hour), M (Q1, Q3)	28 (18, 42)	38 (25, 58)	-3.84	< 0.001

IL-6: Interleukin-6; TNF-α: Tumor necrosis factor-α; IL-10: Interleukin-10; IFN-γ: Interferon-γ; CRP: C-reactive protein; ESR: Erythrocyte sedimentation rate.

Table 6 Comparison of routine blood and biochemical indicators, mean ± SD

Indicator	Non-depression group (n = 89)	Depression group (n = 113)	t/Z value	P value
White blood cell count (× 109/L)	6.8 ± 2.1	7.4 ± 2.5	-1.83	0.069
Lymphocyte count (× 109/L)	1.9 ± 0.6	1.6 ± 0.5	3.89	< 0.001
Neutrophil count (× 109/L)	4.2 ± 1.8	5.1 ± 2.2	-3.15	0.002
NLR [M (Q1, Q3)]	2.1 (1.5, 3.2)	3.1 (2.1, 4.8)	-4.67	< 0.001
PLR [M (Q1, Q3)]	142 (108, 189)	168 (128, 235)	-3.21	0.001
Hemoglobin (g/L)	125 ± 18	119 ± 21	2.14	0.034
Platelet count (× 109/L)	268 ± 82	279 ± 96	-0.87	0.385
Albumin (g/L)	38.6 ± 5.2	36.1 ± 6.1	3.08	0.002
Prealbumin (g/L)	0.24 ± 0.08	0.21 ± 0.07	2.79	0.006
Total protein (g/L)	69.8 ± 7.3	67.4 ± 8.6	2.15	0.033

NLR: Neutrophil-to-lymphocyte ratio; PLR: Platelet-to-lymphocyte ratio.

Table 7 Correlation analysis of Patient Health Questionnaire-9 scores and immune function indicators

Indicator	Correlation coefficient (r)	P value	Correlation type
CD3+ cell count	-0.312	< 0.001	Spearman
CD4+ cell count	-0.367	< 0.001	Spearman
CD4+/CD8+ ratio	-0.289	< 0.001	Pearson
NK cell count	-0.298	< 0.001	Pearson
Complement C3	-0.245	0.001	Pearson
Complement C4	-0.263	< 0.001	Pearson
IL-6	0.456	< 0.001	Spearman
TNF-α	0.398	< 0.001	Spearman
IL-10	-0.287	< 0.001	Pearson
IFN-γ	-0.324	< 0.001	Pearson
CRP	0.372	< 0.001	Spearman
ESR	0.335	< 0.001	Spearman
NLR	0.418	< 0.001	Spearman
Lymphocyte count	-0.356	< 0.001	Pearson
Albumin	-0.294	< 0.001	Pearson

NK: Natural killer; IL-6: Interleukin-6; TNF-α: Tumor necrosis factor-α; IL-10: Interleukin-10; IFN-γ: Interferon-γ; CRP: C-reactive protein; ESR: Erythrocyte sedimentation rate; NLR: Neutrophil-to-lymphocyte ratio.

Table 8 Multiple linear regression analysis of factors affecting depressive symptoms

Variable	B	Standard error	β	t value	P value	95%CI
Constant	15.867	3.245	-	4.89	< 0.001	9.468-22.266
IL-6 (ln transformed)	2.186	0.324	0.365	6.75	< 0.001	1.547-2.825
CD4+ cell count	-0.008	0.002	-0.234	-4.12	< 0.001	-0.012 to -0.004
TNM stage	1.247	0.386	0.178	3.23	0.001	0.486-2.008
NLR (ln transformed)	1.834	0.567	0.198	3.24	0.001	0.716-2.952
Albumin	-0.156	0.078	-0.124	-2.00	0.047	-0.310 to -0.002

Model goodness of fit: R² = 0.524, adjusted R² = 0.512, F = 43.02, P < 0.001; variance inflation factor all < 3.0, no multicollinearity. IL-6: Interleukin-6; TNM: Tumor-node-metastasis; NLR: Neutrophil-to-lymphocyte ratio; CI: Confidence interval.

Table 9 Receiver operating characteristic curve analysis of immune indicators for predicting depressive symptoms

Indicator	AUC	95%CI	P value	Optimal cutoff value	Sensitivity	Specificity	Youden index
IL-6 (pg/mL)	0.782	0.719-0.844	< 0.001	6.35	71.7	75.3	0.470
CD4+ cell count (cells/μL)	0.731	0.664-0.798	< 0.001	798	69.0	70.8	0.398
NLR	0.698	0.627-0.769	< 0.001	2.65	66.4	67.4	0.338
TNF-α (pg/mL)	0.682	0.609-0.754	< 0.001	16.8	63.7	68.5	0.322
CRP (mg/L)	0.671	0.598-0.744	< 0.001	8.9	61.9	66.3	0.282

AUC: Area under the curve; CI: Confidence interval; IL-6: Interleukin-6; NLR: Neutrophil-to-lymphocyte ratio; TNF-α: Tumor necrosis factor-α; CRP: C-reactive protein.