The Impact Of Immunosuppressive Therapy In Bone Metabolism After Renal Transplantation

In21st century, the organ transplantation has become an effective method for the treatment of end-stage of kidney, liver, heart, and lung diseases. With the increase in the number of all types of transplantation, the survival time, survival rates of the transplant patients are also rising, and the longest survival time of the patients after renal transplantation had reached40years. The gradual increase in the survival rates of the transplant patients year by year is closely associated to the applications of the postoperative immunosuppressants. After renal transplantation, the recipients are bound to be exposed to large doses of immunosuppressant drugs, these durgs weaken the rejection of transplanted organs to promote the long-term survival time of recipients but also produce toxic effects to bones to make many patients get osteoporosis and fractures. Bone disease after renal transplantation, as a common long-term complication after renal transplantation, has reduced both the postoperative life quality and survival time of the transplant patients, worthy of our attention.Objective:Through the collection of the biochemical markers such as blood calcium (Ca), phosphorus (P), bone metabolism indicators (bone formation indicators-osteocalcin in BPG, bone resorption indicators-deoxypyridinoline (DPD) in urine), as well as bone-mineral density (BMD) test results, the postoperative changes in bone metabolism were analyzed quantitatively, so as to identify the change law of bone metabolism, and finally providing a reference basis for the prevention and treatment of the bone disease after renal transplantation.Methods:Through the collection of clinical information of patients, especially the survive time and drug use after transplantation,, based on the self-control,4observation points were established according to the different time points, including preoperative time (postoperative1month should be calculated in the preoperative range), postoperative half year, postoperative1year, postoperative2years. The blood samples, urine samples of the patients were collected, then the former were centrifuged to separate the serum, the serum and urine were stored in a ultra-low temperature refrigerator. The samples were submitted to laboratory after the completion of the collection of40cases of samples, so as to determine their biochemical markers such as blood calcium (Ca), phosphorus (P), bone metabolism indicators (bone formation indicators-osteocalcin in BPG, bone resorption indicators-deoxypyridinoline (DPD) in urine), and the BMDs of the lumbar1-4(L1-4), the left femoral necks (FN) and Ward’s triangle of the subjects were also determined by the dual-energy X-ray absorptiometry. A quantitative analysis was performed based on the data obtained from the determination on the samples collected from clinical patients, so as to explore the trends and characteristics of the bone metabolism in every group of patients.Results:In this study, the changes of Ca, P in the serum of the recipients at four observation points had no significant differences, but the bone metabolism indicators osteocalcin in BPG and DPD in urine increased (p<0.05or p<0.01), and they showed increasing trends with the increase of the treatment time; the determination for the BMDs of all parts of bones showed the BMDs decreased in postoperative1year of immunosuppressive treatment, and the BMDs of L1-4, FN and Ward’s triangle in postoperative half year also had significant difference with those before treatment.(p<0.05orp<0.01).Conclusion:After renal transplantation, the recipients are bound to be exposed to large doses of immunosuppressant drugs, these durgs produce toxic effects to bones, so the rapid losses of bone mass and the fractures caused by osteoporosis fractures were common seen in the postoperative1year, in early stage of postoperative bone mass loss, these phenomena are related to the increase of the bone formation indicators and the increase of bone resorption indicators, and also have a certain of relationship with the biochemical uncoupling in bone remodeling. Because the bone diseases often appear before the transplantation, the recipients who are ready to receive bone grafts should be tested for BMD, bone metabolism indicator, and be performed the related biochemical tests, so as to early detect the abnormal bone metabolism of osteoporosis, and early control to correct the loss of bone mass. And the recipients should be immediately received medication after transplantation in order to prevent bone loss and fractures.