1. Immunological Aspects

1. Immunological Aspects

In recent years, numerous domestic experimental studies have suggested that methods of strengthening the spleen and tonifying the kidneys can improve the body’s immune function. Strengthening the spleen primarily enhances non-specific immunity, while tonifying the kidneys mainly improves specific immunity. Non-specific immunity refers to defense mechanisms that act without selectivity, such as the skin-mucosal barrier, blood-brain barrier, blood-fetal barrier, reticuloendothelial system, and phagocytic activity of neutrophils. Specific immunity, on the other hand, is highly targeted, only acting against corresponding pathogens, and its function is carried out by immune-active T cells and antibodies present in body fluids that correspond to antigens.

The spleen and stomach occupy the central position; the “Wei Qi” that the human body relies on for defensive functions originates from food and water and is produced in the spleen and stomach. Therefore, the strength of spleen and stomach function directly affects the rise and fall of Wei Qi. The “Ling Shu·Ben Cang Pian” states: “Wei Qi is what warms the flesh and muscles, fills the skin, makes the pores and skin soft, and controls opening and closing.” It also says: “When Wei Qi is balanced, the flesh and muscles are relaxed, the skin is smooth, and the pores and skin are tightly closed.” This shows that Wei Qi is an important factor in clearing foreign pathogens from peripheral tissues such as muscles, skin, and mucous membranes, and plays a role in maintaining the skin-mucosal barrier. When Wei Qi vigorously fights off invading pathogens, the intense struggle between the two leads to disease. The “Su Wen·Mao Lun” says: “Wherever Wei Qi resides, it combines with evil qi to cause illness.” This phenomenon is very similar to the phagocytic action of the reticuloendothelial system. Sometimes Wei Qi can even surround invading “evil qi,” causing local abscesses, just as the “Su Wen·Feng Lun” says: “Wind qi enters the meridians together with the sun, spreads among the flesh and muscles, interacts with Wei Qi, and since the pathway is blocked, the muscles become swollen and develop sores.” This illustrates how similar Wei Qi is to the phagocytic action of neutrophils in immunology. Wei Qi’s role is not limited to skin, flesh, and pores; it also protects internal organs. The “Ling Shu·Wei Qi Xing Pian” says: “It starts in the yin, often flows from the Shaoyin foot to the heart, then to the lungs, then to the spleen, and finally returns to the kidneys, completing a cycle.” This shows that Wei Qi can circulate through various organ meridians, much like the dispersed reticuloendothelial system and the systemic fluid circulation throughout the body. The above discussion demonstrates that Wei Qi has a function similar to non-specific immunity in modern immunology; however, the primary factor determining the rise and fall of Wei Qi is the strength of spleen and stomach function. Traditional Chinese medicine’s use of Bu Zhong Yi Qi Tang to strengthen spleen and stomach function, thereby preventing colds, is a clinical application of this view. Recent domestic experiments have shown that Bu Zhong Yi Qi Tang can indeed improve protein metabolism in tumor-bearing organisms and increase non-specific immunity. The Isotope Laboratory of the Beijing Tuberculosis Research Institute injected animals intravenously with ^131^ iodinated plasma protein colloidal solution and measured the clearance rate in the blood as an indicator of the reticuloendothelial system’s phagocytic function, finding that spleen-strengthening herbs like Dangshen, Baizhu, and Huangqi enhance the reticuloendothelial system’s phagocytic ability, whereas control group herbs like Shashen, Baihe, Beimu, and Huangqin, which nourish yin and clear heat, do not have this effect. The Tumor Group of the Beijing Institute of Traditional Chinese Medicine found that Dangshen increases the number of white blood cells in peripheral blood; Jiang Tingliang injected rabbits with extracts of this herb, increasing the proportion of neutrophils in the peripheral blood. These experiments suggest that spleen-strengthening herbs like Dangshen can enhance the defensive function of white blood cells and boost non-specific immunity. The Guang’anmen Hospital of the Chinese Academy of Traditional Chinese Medicine measured the phagocytic function of macrophages in 89 patients with malignant tumors, finding that their phagocytic rates were significantly lower than normal. Among them, five cervical cancer patients showed a significant increase in macrophage phagocytic function after receiving spleen-strengthening treatment. The above data show that spleen-strengthening methods can indeed enhance the defensive efficiency of macrophages, neutrophils, and the reticuloendothelial system, providing experimental evidence for the view that strengthening the spleen can regulate non-specific immunity.

The kidney is the foundation of innate vitality and the source of life. The “Su Wen·Sheng Qi Tong Tian Lun” says: “When yin is balanced and yang is concealed, the spirit is healthy,” and also: “When yin and yang are separated, vital essence is extinguished,” indicating that balance between yin and yang is a prerequisite for maintaining a normal ecological state. The root of yin and yang is the kidney, hence the terms “original yin” and “original yang.” Imbalance in kidney qi is often the key factor causing overall imbalance between yin and yang. Modern immunology believes that the functions of T cells dependent on the thymus and B cells independent of the thymus are the main components of specific immunity, and the precursors of these two types of cells are stem cells located in the bone marrow. The “Su Wen·Yin Yang Ying Xiang Da Lun” says: “The kidney produces bone marrow,” thus inferring that the transformation of bone marrow stem cells into T cells and B cells is closely related to the kidney. Therefore, by regulating kidney yin and kidney yang, it is hoped that the body’s specific immune response can be improved. The Shanghai Cancer Research Institute used crude fetal alpha-globulin as an antigen to immunize rabbits, inducing an immune response, then divided them into groups fed kidney-yin-tonifying drugs and kidney-yang-tonifying drugs, measuring antibody levels. The results showed that kidney-yang-tonifying drugs could accelerate antibody formation, while kidney-yin-tonifying drugs could prolong antibody survival, indicating that kidney-tonifying therapy can improve specific humoral immunity. The Department of Traditional Chinese Medicine at the Affiliated Hospital of Guangzhou Medical College conducted rose flower tests on patients with chronic bronchitis of kidney-deficiency type to measure their specific cellular immunity, finding that the ratio of T cells in these patients was generally low. After administering kidney-tonifying traditional Chinese medicines, the ratio of T cells gradually increased, and clinical symptoms also improved accordingly. According to the Chronic Bronchitis Office of the Henan Health Bureau, measuring the IgA content in the sputum of chronic bronchitis patients from the perspective of specific humoral immunity revealed that after treatment with kidney-tonifying drugs such as rabbit placenta, the IgA content in the patients’ sputum tended to increase. The First Outpatient Clinic of the Chengdu Military Region administered serum IgG and IgA tests to more than 50 patients with chronic bronchitis of kidney-deficiency type, finding that their values were all below normal. After applying warming and kidney-yang-tonifying medications via navel patches, these indicators all increased to varying degrees. The above data show that kidney-tonifying methods can enhance the conversion of T cells into lymphoblasts and promote the release of lymphokines, strengthening the function of immunoglobulins in body fluids, thus providing experimental evidence for the argument that “kidney qi” possesses specific immune function.