The mechanisms of the chronic pain and depression comorbidity have gained significant attention in recent years. The complement system, widely involved in central nervous system diseases and mediating non-specific immune mechanisms in the body, remains incompletely understood in its involvement in the comorbidity mechanisms of chronic pain and depression. This review aims to consolidate the findings from recent studies on the complement system in chronic pain and depression, proposing that it may serve as a promising shared therapeutic target for both conditions. Complement proteins C1q, C3, C5, as well as their cleavage products C3a and C5a, along with the associated receptors C3aR, CR3, and C5aR, are believed to have significant implications in the comorbid mechanism. The primary potential mechanisms encompass the involvement of the complement cascade C1q/C3-CR3 in the activation of microglia and synaptic pruning in the amygdala and hippocampus, the role of complement cascade C3/C3a-C3aR in the interaction between astrocytes and microglia, leading to synaptic pruning, and the C3a-C3aR axis and C5a-C5aR axis to trigger inflammation within the central nervous system. We focus on studies on the role of the complement system in the comorbid mechanisms of chronic pain and depression.

The mechanisms of the chronic pain and depression comorbidity have gained significant attention in recent years. The complement system, widely involved in central nervous system diseases and mediating non-specific immune mechanisms in the body, remains incompletely understood in its involvement in the comorbidity mechanisms of chronic pain and depression. This review aims to consolidate the findings from recent studies on the complement system in chronic pain and depression, proposing that it may serve as a promising shared therapeutic target for both conditions. Complement proteins C1q, C3, C5, as well as their cleavage products C3a and C5a, along with the associated receptors C3aR, CR3, and C5aR, are believed to have significant implications in the comorbid mechanism. The primary potential mechanisms encompass the involvement of the complement cascade C1q/C3-CR3 in the activation of microglia and synaptic pruning in the amygdala and hippocampus, the role of complement cascade C3/C3a-C3aR in the interaction between astrocytes and microglia, leading to synaptic pruning, and the C3a-C3aR axis and C5a-C5aR axis to trigger inflammation within the central nervous system. We focus on studies on the role of the complement system in the comorbid mechanisms of chronic pain and depression.

The mechanisms of the chronic pain and depression comorbidity have gained significant attention in recent years. The complement system, widely involved in central nervous system diseases and mediating non-specific immune mechanisms in the body, remains incompletely understood in its involvement in the comorbidity mechanisms of chronic pain and depression. This review aims to consolidate the findings from recent studies on the complement system in chronic pain and depression, proposing that it may serve as a promising shared therapeutic target for both conditions. Complement proteins C1q, C3, C5, as well as their cleavage products C3a and C5a, along with the associated receptors C3aR, CR3, and C5aR, are believed to have significant implications in the comorbid mechanism. The primary potential mechanisms encompass the involvement of the complement cascade C1q/C3-CR3 in the activation of microglia and synaptic pruning in the amygdala and hippocampus, the role of complement cascade C3/C3a-C3aR in the interaction between astrocytes and microglia, leading to synaptic pruning, and the C3a-C3aR axis and C5a-C5aR axis to trigger inflammation within the central nervous system. We focus on studies on the role of the complement system in the comorbid mechanisms of chronic pain and depression.

Objective:To investigate the application and surgical effect of lobed anterolateral femoral chimeric perforator flap in repairing the complex soft tissue defects of limbs.Methods:Clinical materials of 52 cases with complex soft tissue defects of limbs were retrospectively reviewed from October 2013 to October 2020. Thirty-two males and 20 females were reviewed, and the age of them ranged from 6 to 65(mean 39) years old. The injuries include 17 cases of traffic accidents, 15 machine crush injuries, 12 engineering accidents, and 8 extensive resection of malignant tumors. The size of soft tissue defects ranged from 26.0 cm×10.0 cm to 35.0 cm×15.0 cm. Lobed anterolateral thigh chimeric perforator flaps or lobed Flow-through chimeric perforator flaps were designed according to the soft tissue defects and blood circulation of the distal extremities. Start from 8-month post-operation, upper limb function was assessed according to the Upper Limb Function Assessment Standard of Hand Surgery Branch of Chinese Medical Association and Disability of arm shoulder and hand(DASH) score scale, and Fugl-Meyer score system was used to evaluate the lower limb function. Long-term follow-up was conducted through WeChat video call and outpatient clinic evaluation.Results:All flaps survived. One patient with crush injury got delayed wound healing due to deep hemaetoma after surgery, and the rest were healed at the first stage. All the cases entered followed-up, ranged from 6 to 20(mean 8) months. The appearance of the flaps was satisfactory, and the color of the flaps has no significant difference compared with the recipient area. No recurrence of tumor was reported during the follow-up period. According to the Upper Limb Function Assessment Standard of Hand Surgery Branch of Chinese Medical Association, there were 21 excellent cases and 8 good cases, and the total excellent and good rate was 100%. The DASH score of upper limbs ranges from 11.5 to 45.1(mean 25.4±13.7), and the Fugl-Meyer score of lower limbs range from 18.6 to 31.8(mean 26.2±11.2) at the last follow-up.Conclusion:The complex soft tissue defect of limbs is a common complication caused by high-energy trauma, which is difficult to repair. The lobed anterolateral thigh chimeric perforator flap through a Decompose-Combine and arrange method for reconstruction, which is flexible in flap design. A variety of tissue flaps can be obtained by anastomosing only one group of blood vessels. It is an ideal choice for repairment of complex soft tissue defects of limbs.