Highly HLA Sensitized Kidney Transplant Patients in a Transplant Center

Malignancy Diseases in Kidney Transplantation, Clinical Outcomes, Patient, and Allograft Survival: A Case-Control Study

BACKGROUND

Malignancy is a well-known complication in patients after kidney transplantation (KT), but its effect on posttransplant outcomes, allograft, and patient survival remains unexplored. The aim of this study is to report the impact of the comorbidity on clinical outcome, function, and failure of an allograft kidney.

METHODS

This case-control study included 101 KT patients. Twenty-six patients who developed cancer (CA) were assigned to the case group and 75 to the control group. Statistical analysis was performed using logistic regression models, and graft survival was analyzed using the Kaplan-Meier curve.

RESULTS

Non-melanoma skin CA was the most common malignancy, accounting for almost 60% of cases, followed by stomach CA, prostate CA, and lymphoproliferative diseases (7.70% each). Difference in graft and patient survival was not significant between the two groups (P > .05). A tumor in nonfunctioning in the first nonfunctioning KT was identified in 1 KT patient with a second allograft and by anatomopathological was detect Fuhrman grade II renal cell carcinoma. This KT patient was in good clinical condition with serum creatinine level of 1.5 mg/dL.

CONCLUSIONS

No association was observed between CA development and risk factors, including family history and smoking habit, and no differences in allograft and patient survival were found. Nevertheless, in our data, CA in KT patients occurred early after transplantation. Renal cell carcinoma in allograft failure was identified in a patient; that suggested that nephrectomy of kidney failure must be performed to avoid patient allosensitization and neoplasia. Thus, we suggest continuous screening of malignancy diseases for KT patients.

Disparity in the access to kidney transplantation for sensitized patients in the state of Sao Paulo-Brazil

Highly sensitized (HS) patients accumulate on deceased donor kidney transplantation (DDKT) waitlists worldwide due to matching difficulty and inequity of allocation policies. Current situation of HS patients on KT waitlist in Brazil has not been published. All patients enrolled on the KT waitlist of the State of São Paulo from 2002 to 2017 were retrospectively assessed. Patients were divided into eight groups according to their degree of sensitization, PRA of 0%, >0-40%, >40-80%, >80-85%, >85-90%, >90-95%, >95-98% and > 98%. Cumulative incidence curves for transplantation or mortality/removal from waitlist were estimated by competing risk. Among 50,249 waitlisted candidates, 1247 prioritized, 2467 with age < 18 or > 75 years and 4152 submitted to living-donor KT were excluded from the analysis, remaining 42,383 patients. There were 29,664(70%) PRA 0%, 5611(13.2%) PRA > 0-40%, 3442(8.2%) PRA > 40-80%, 507(1.2%) PRA > 80-85%, 564(1.3%) PRA > 85-90%, 825(1.9%) PRA >90-95%, 859(2%) PRA > 95-98% and 911(2.2%) PRA > 98%. There was a progressive increase in the need of prioritization, waiting time for KT or on waitlist and time on dialysis as PRA increased (p < 0.001). Probability of DDKT clearly increased as PRA decreased so that PRA 0% candidates were much more likely to be transplanted compared to PRA > 98% patients(HR:13.02, p < 0.001). Waiting list mortality/removal was higher among PRA > 0-40%(HR1.05,p = 0.03), PRA > 90-95%(HR:1.10,p = 0.05), PRA > 95-98%(HR:1.26,p < 0.001) and PRA > 98%(HR:1.09,p = 0.05) patients compared to PRA zero candidates. HS patients in Sao Paulo-Brazil required greater prioritization due to lack of venous access, longer dialysis and waitlist times, lower probability of DDKT and higher rates of waitlist mortality/removal. We confirmed the disparity of access to KT among HS patients in Sao Paulo-Brazil, indicating the need of new strategies that optimize transplantation for this subcategory of patients.

Investigation of Anti-HLA Antibodies of Highly Sensitized Patients by Single Antigen Bead and C1q Tests

PURPOSE

The single antigen bead (SAB) test contributes to conventional cellular and solid phase crossmatch tests in renal transplantation. However, the determination of anti-HLA antibodies of the patients may not reflect the pathologic features of these antibodies. Highly sensitized patients produce antibodies against a number of HLAs; therefore, their transplantation chance decreases. In this study, we aimed to evaluate SAB and C1q test results of highly sensitized patients.

METHOD

In this study, 33 end-stage renal failure patients with >80% panel reactive antibody were included. Of the patients, 58% (n = 19) were female, and 42% (n = 14) were male. The mean age was 46.2 ± 12.4. All of the serum samples were inactivated by heat before use. SAB and C1q tests were performed according to the manufacturer's instructions.

RESULTS

We obtained statistically significant results between the positive bead counts and raw mean fluorescence intensity (MFI) values of 2 tests (P < .01 for class I and II). There was a statistically significant difference between the 2 tests in terms HLA-A, -C, -DR, and -DP MFI values, whereas HLA-B and -DQ MFI values were similar for the 2 tests.

CONCLUSION

The difference of raw MFI values between the 2 tests may be due to the fact that the C1q test detects only IgG1 and IgG3 antibodies, whereas the SAB test can detect all IgG subtypes. We considered that anti-HLA-B and -DQ antibodies have high complement-fixing features; these antibodies should be investigated selectively due to the similarity of anti-HLA-B and -DQ antibody MFI values in the 2 tests.