Cancer Screening of Renal Transplant Patients Undergoing Long-Term Immunosuppressive Therapy

OBJECTIVE

With this study we aimed to research the effects of immunosuppressive drugs, their cumulative doses, and viral infections on development of malign tumors in patients who have undergone treatment for 5 years.

METHODS

We examined 100 patients who underwent renal transplantation from 2004 to 2009. Patients had mycophenolate mofetil and steroid in addition to cyclosporine, sirolimus, or tacrolimus as immunosuppressive treatment. For malignancy screening, physical examination, radiologic and endoscopic screening were done, and immunosuppressive drugs and their cumulative doses, age, sex, body mass index (BMI), dialysis history, and viral infection history were investigated.

RESULTS

The mean age of patients was 42.03 ± 11.30 years. There were 1 colon cancer patient, 1 retroperitoneal liposarcoma, 1 renal oncocytoma, 3 Kaposi sarcoma patients treated with cyclosporine; in those treated with Tac there were 1 basal cell carcinoma, 1 Kaposi sarcoma, 2 thyroid carcinoma, 1 breast carcinoma, 1 bladder carcinoma, 1 renal cell carcinoma, and 1 colon carcinoma patients. The mean age of patients having carcinoma was statistically significant compared with those without cancer (P < .01). The prednisolone cumulative dose was significantly higher in carcinoma patients than in patients without carcinoma (P < .01).

RESULTS

The use of long-term chronic immunosuppressive therapy may increase the development of cancer. The risk of carcinoma increases with increasing drug dose and time period of the immunosuppressive drug. There was not a negative effect on cancer prevalence in patients with cyclosporine or tacrolimus. But the cumulative dose of steroids significantly increased malignancy occurence.

The impact of C4d staining as a humoral injury marker

PURPOSE

Acute and chronic humoral injuries in renal transplant recipients are the main reasons for graft rejection and failure. Histological and clinical characteristics of humoral rejection and symptoms are variable and not always helpful for differential diagnosis. Clinical monitoring of the allograft, an elevated serum panel-reactive antibody (PRA), and the presence of donor-specific antibody (DSA) during immune monitoring as well as C4d staining of biopsy material can establish the differential diagnosis. Even without a cellular component, humoral rejection reaction is serious because the target tissue is the graft endothelium. Because the kidney graft has a rich vascular structure this attack causes permanent injury to the kidney in the long term. Graft dysfunction in this setting is usually more severe, requiring dialysis therapy, compared with acute cellular reactions. Positive C4d staining of peritubular capillaries in biopsy material represent a hallmark of complement-dependent cytotoxicity, supporting the diagnosis of humoral rejection. We analyzed C4d staining as a hallmark of humoral rejection.

METHODS

From 2009 to 2011, we analyzed the relationship between pathological findings of C4d immunohistochemistry staining and the clinical outcomes of 45 kidney transplant recipients who underwent a kidney biopsy because of graft dysfunction due to possible humoral rejection.

RESULTS

Biopsy specimens of 15 patients stained C4d positive; the remaining 30 showed negative results. Intravenous steroids, PP + IVIG with or without antithymocyte globulin (ATG), was administered for treatment. Sixty six percent (n = 10) of patients were C4d positive with 16% (n = 5) of those showing C4d-negative biopsy results, losing their grafts, and returning to hemodialysis.

CONCLUSIONS

C4d staining refractory humoral rejection injury was related to poor graft outcomes.

Flow cytometric detection of anti-AB antibody titers in blood group O recipients of blood group A2 donor kidneys

AIM

ABO-incompatible kidney transplantation has been accepted for end-stage renal failure patients who have no ready opportunity for a deceased or living donor. Antibody titration for ABO-incompatible renal transplantation is not only difficult but also lacks conformity among laboratories. Herein we analyzed 20 living related renal transplant couples to detect recipient anti-A2 antibody using flow cytometric analysis.

MATERIALS AND METHODS

Patients were admitted to our center for renal transplantation between January 1999 and December 2010. All but four of them had undergone a previous renal transplantation from an ABO-compatible donor but experienced graft failure. All donor blood groups were subtyped by our blood bank using a lectin-based dilution assay. To detect recipient anti-A2 antibody titers we used a tube hemagglutination method. A/B antibody titer analysis by flow cytometry incubated serially diluted serum samples with donor erythrocytes. Each analysis was repeated three times over a 2-week period using an older and the last sera simultaneously.

RESULTS

The 13 male and 7 female patients showed our overall mean age of 32 ± 12 years. All patients had panel-reactive antibody levels below 15%. The level of flow cytometric antibody titers did not vary upon repeated analysis (P = .01). When compared with the tube method there was a discrepancy of the level at which the antibody titer became negative.

DISCUSSION

Flow cytometric antibody titration is a practical and rapid technique to determine the amount of anti-A2 antibody in renal recipients.