Relationship between depression and serum immunosuppressive acid protein in patients with advanced digestive tract cancers

AIM: To explore the relationships among depression, the degree of immunosupressive acidic protein (IAP), and the percentage of CD3, CD4, CD8, and NK in elderly patients with advanced digestive tract cancers; and to determine the effects of antidepressant therapy.

METHODS: Forty-three elderly patients with advanced digestive tract cancers were randomly enrolled in the study and divided into two groups. The degree of depression was evaluated by the Zung self-rating depression scale (SDS). IAP was examined by simple agar diffusion. Immunological parameters such as the percentage of T-lymphocyte subsets and natural killer (NK) cells in peripheral blood were determined and compared between the two groups of patients by flow cytometry. Patients who were depressed according to the scores of the SDS took antidepressant therapy. After patients were assessed as normal, the immunological parameters were again determined.

RESULTS: The depression rate was 44%. SDS was positively correlated with the level of IAP (r = 0.549, P < 0.01), negatively correlated with the percentages of CD3 and CD4 (r = -0.163, P < 0.001 and r = -0.163, P < 0.001), and had no relationship with the percentages of NK or CD8 (r = 0.262, P > 0.05 and r = 0.611, P > 0.05). The two groups showed significant differences of IAP, CD3 and CD4 (IAP: 908.33 ± 275.75 mg/L vs 537.60 ± 282.64 mg/L, P < 0.01; CD3: 67.05 ± 13.12 vs 73.27 ± 8.03, P < 0.05; and CD4: 36.68 ± 11.29 vs 43.72 ± 9.16, P < 0.05) between the depressed and non-depressed groups. The change of IAP before and after antidepressant therapy was statistically significant (P < 0.01). The levels of CD3, CD4, CD8, and NK between the two groups showed no obvious changes (P > 0.05).

CONCLUSION: There is a high rate of depression in elderly patients with cancers of the digestive tract. Antidepressant treatment was found to improve immune function.