Correlations between major depressive disorder, splenic morphology and immunity

Abstract

To explore the symptoms, course and severity of depressive disorder and the morphological changes of spleen and immune-related mechanism. We recruited patients with first-episode or recurrent major depressive disorder（MDD）(patient group) and healthy controls (normal group) matched in age and gender. All subjects’ plasma MICB (pg/ml), ULBP1 (ng/ml) and splenic volume (cm3) were measured at baseline. The patient group was randomly assigned to receive (S)-ketamine (study group) and non-(S)-ketamine (control group), and the above indexes were collected again on the 4th weekend after administration. At baseline, the MICB and splenic volume in patient group were significantly higher than those in normal group. There appears a positive correlation between MICB and splenic volume in the patient group. After administration of (S)-ketamine, the higher splenic volume and MICB decreased. The results indicate that the pathogenesis of MDD may involve abnormal changes in MICB expression and splenic morphology. (S)-ketamine may ameliorate the inflammation and enhance splenic function to relieve MDD symptoms.