Objective Prokaryotic system was used to induce expression and purification of human leukocyto antigen-G1（HLA-G1） protein and to investigate the effect of HLA-G1 on expression of interleukin-10 （IL-10）in hunman B lymphocytes， to study the B cell-mediated immune tolerance mechanism of HLA-G1 in kidney transplantation recipients. Methods We used the prokaryotic expression system to express the HLA-G1 protein and purified it. Human peripheral blood mononuclear cells（PBMCs） were co-cultured with HLA-G1 after Western Blot. Then we detected the expression of IL-10 in B lymphocytes by flow cytometry. Results Results of sodium dodecyl sulfate-polyacrylamide gel（SDS-PAGE） and Western Blot showed that the molecular weight of the purified protein was about 38.2 kDa which was in accord with that of HLA-G1 protein. The expression of IL-10 in B lymphocytes after co-culture with HLA-G1 significantly increased， and the rate of IL-10 on B lymphocytes were 0.1%，0.36%，0.57% and 0.73%， respectively， dependent on the concentration of HLA-G1（concentration gradient： 0，50，100 and 200 ng/ml）. Conclusion We used the prokaryotic expression system to express HLA-G1 protein and purified it. The purity was above 95%. HLA-G1 protein induced the expression of IL-10 in B lymphocytes in a concentration dependent manner after co-culture with human PBMC， which suggested that HLA-G1 might play an important role in the establishment of immune tolerance in kidney transplantation.

Objective Prokaryotic system was used to induce expression and purification of human leukocyto antigen-G1（HLA-G1） protein and to investigate the effect of HLA-G1 on expression of interleukin-10 （IL-10）in hunman B lymphocytes， to study the B cell-mediated immune tolerance mechanism of HLA-G1 in kidney transplantation recipients. Methods We used the prokaryotic expression system to express the HLA-G1 protein and purified it. Human peripheral blood mononuclear cells（PBMCs） were co-cultured with HLA-G1 after Western Blot. Then we detected the expression of IL-10 in B lymphocytes by flow cytometry. Results Results of sodium dodecyl sulfate-polyacrylamide gel（SDS-PAGE） and Western Blot showed that the molecular weight of the purified protein was about 38.2 kDa which was in accord with that of HLA-G1 protein. The expression of IL-10 in B lymphocytes after co-culture with HLA-G1 significantly increased， and the rate of IL-10 on B lymphocytes were 0.1%，0.36%，0.57% and 0.73%， respectively， dependent on the concentration of HLA-G1（concentration gradient： 0，50，100 and 200 ng/ml）. Conclusion We used the prokaryotic expression system to express HLA-G1 protein and purified it. The purity was above 95%. HLA-G1 protein induced the expression of IL-10 in B lymphocytes in a concentration dependent manner after co-culture with human PBMC， which suggested that HLA-G1 might play an important role in the establishment of immune tolerance in kidney transplantation.

Objective To investigate the relationship between the average fluorescence intensity and the type of donor-specific antibody （DSA）detected by monoclonal antibody in the sensitized patients before renal transplantation and the early anti-mediated rejection. Methods We retrospectively analyzed the data of 30 sensitized renal transplantation patients from 2012 January to 2014 January in Tianjin First Center hospital. We detected preoperative donor specific antibody using a Luminex platform and analyzed the clinical impact of antibody type and the mean fluorescence intensity（MFI） to early postoperative antibody mediated rejection （AMR）. Results Twenty-two patients had pretransplant DSA， and there were 9 cases of type Ⅰ positive, 7 cases of type Ⅱ positive，6 cases had class Ⅰ and Ⅱ，10 cases （45.5%） had antibody mediated rejection. Comparison AMR positive group with AMR negative group， class Ⅰ DSA MFI and class Ⅰ strong positive DSA （MFI ≥ 8 000） had significant difference （P ＜ 0.05） between the two groups， but the levels of PRA and class Ⅱ DSA had no significant difference （all P ＞ 0.05）. In 7 patients with class Ⅰ strong positive DSA，6 patients （85.7%） had AMR， but in8 cases with class Ⅰ moderate positive DSA （1 000 ＜ MFI ＜ 8 000），2 cases （25%） had AMR， there were statistical difference （P ＜ 0.05）. Preoperative class Ⅰ strong positive DSA had a positive predictive value of 85.7% and a negative predictive value of 75%， and the sensitivity and specificity of AMR was 75% and 85.7%，respectively. Conclusion Preoperative avoidance of strongly positive class Ⅰ DSA can increase the chance of renal transplantation in sensitized patients and reduce the incidence of early postoperative AMR. Preoperative patientspecific antibody stratification analysis can increase the chance of renal transplantation in sensitized patients.

Objective To investigate the clinical effect of ex vivo ureteroscopic holmium laser lithotripsy combined with Lifeport perfusion on donation after citizen's death（DCD） donor kidney with calculi. Methods The calculi in DCD donor kidneys, were treated with ureteroscopic holmium laser lithotripsy, including 5 cases of right kidney stones and 5 cases of left kidney stones . Crushed stone surgery throughout the kidney placed in the ice kidney preservation solution，low pressure, low temperature washing, holmium laser power was 1.2 ~ 1.6 J / 15 ~ 20 Hz. After lithotripsy, all kidneys were preserved by Lifeport mechanical perfusion , and then renal transplantation was performed. The donor's renal ureter was routinely matched to the recipient's bladder and the 6 F D-J tube was left. Results One patient had delayed recovery of renal function. All patients underwented cystoscopy at 4 weeks after operation for pulling out D-J tube. Patients were followed up for 3 to 22 months. No hydronephrosis was found in the color Doppler ultrasonography. Two patients encountered stone recurrence in graft kidney after one year of transplatation with stable kidney function. Conclusion Ex vivo ureteroscopic holmium laser lithotrpsy combined with Lifeport perfusion treatment of calculi in DCD donor kidneys is an effective method to expand the donor kidney pool, and the clinical curative effect is good.

Objective To investigate diagnostic methods and principles of treatment of acute antibodymediated rejection （AAMR） after kidney transplantation. Methods To analyze the clinical diagnosis and treatment of AAMR in 4 cases of renal transplantation Results Two patients with panel reaction antibody（PRA） positive and 2 patients with PRA negative before transplantation received kidney transplantation，3 patients received kidneys from donors after citizen's death（DCD） and 1 patient from his mother， PRA level， donor special antibody（DSA） and pathology of biopsy of transplanted kidneys were diagnosed as AAMR，2 cases of renal function returned to normal, while others failed to escape from hemodialysis after treatment of AAMR including plasmapheresis， bortezomib for injection， intravenous immunogloblin. Conclusion Renal transplantation after AAMR rejection is one of the leading causes of transplanted renal dysfunction, early diagnosis and treatment is the key to improve the prognosis.