Returning to haemodialysis after kidney allograft failure: a survival study with propensity score matching.

BACKGROUND: Patients who return to dialysis after kidney allograft failure (KAF) are classically considered to have lower survival rates than their transplant-naïve incident dialysis counterparts. However, this observation in previous comparisons could be due to poor matching between the two populations. METHODS: To compare survival rates between patients who returned to haemodialysis (HD) after KAF versus transplant-naïve incident HD patients, we performed a retrospective study using the EuCliD® database (European Clinical Database) that collects data from Fresenius Medical Care (FMC) outpatient HD facilities in Spain. Propensity score matching (PSM) was performed to homogenize both populations. RESULTS: This study included 5216 patients from 65 different FMC clinics between 2009 and 2014. Naïve incident HD patients were mostly male, older, comorbid and more commonly had catheters as vascular access. During the study follow-up, 3915 patients exited, of whom 1534 died. The mean survival time for the entire cohort was 4.86 years [95% confidence interval (CI) 4.78-4.94]. Univariate Cox analysis indicated higher mortality risk among transplant-naïve incident HD patients [hazard ratio (HR) 1.728; 95% CI 1.35-2.21; P < 0.001). However, this difference was no longer significant after multivariate adjustment. After applying PSM to minimize the bias due to indication issue, we obtained an adjusted population composed of 480 naïve and 240 KAF patients. The results analysing the PSM-adjusted cohort confirmed similar survival in both cohorts (log-rank, 3.34; P = 0.068; HR 1.382; 95% CI 0.97-1.95; P = 0.069). CONCLUSIONS: When comparing properly matched patient groups, patients who return to HD after KAF present similar survival than survival than transplant-naïve incident patients.

Antiphospholipid antibodies after renal transplantation and cardiovascular disease.

BACKGROUND: The aim was to assess the presence of pre- or post-transplant serum antiphospholipid antibodies (APA) and its association with the development of cardiovascular disease (CVD) in renal transplantation. METHODS: We studied 138 patients transplanted with a cadaver kidney graft between 1990 and 1998 and with a graft functioning for longer than one yr. One pre-transplant sample and another obtained after transplantation from our serum bank were analyzed. The ELISA used were set up in our laboratory, following established international guidelines, and results were confirmed in three different runs. RESULTS: 23.9% and 31.2% of patients had pre- and post-transplant positive titers of APA, respectively. 16% developed those antibodies de novo after transplantation. Post-transplant CVD was observed in 20.3% of patients but they were not associated with the production of APA in the whole population studied. However, multivariate analysis demonstrated an increased risk (RR 2.27; p = 0.02) for CVD when APA were produced after acute rejection. CONCLUSIONS: The presence of serum APA alone was not an independent risk factor for CVD after kidney transplantation. Nonetheless, in kidney recipients who produced APA de novo after acute rejection, the control of cardiovascular risk factors must be intensified.

Modulation of autoantibody production by mycophenolate mofetil: effects on the development of SLE in (NZB x NZW)F1 mice.

BACKGROUND: Mycophenolate mofetil (MMF) has been successfully used to improve or prevent the development of systemic lupus erythematosus (SLE) in both humans and in several lupus-prone mice. In the present study, we evaluated mechanisms through which MMF may exert its therapeutic effect on the development of systemic autoimmunity. METHODS: (NZBxNZW)F(1) female mice were continuously treated with 100 mg/kg/day (high dose) or 30 mg/kg/day (low dose) MMF beginning at 3 months of age. The development of an autoimmune syndrome was evaluated by measuring immunoglobulin (Ig) isotypes of autoantibodies and their levels, as well as by evaluating immunopathological kidney abnormalities and mortality curves. RESULTS: At both doses, MMF efficiently modulated the development of SLE. Although the higher dose of MMF directly inhibited the production of autoantibodies, 30 mg/kg/day MMF promoted qualitative but not quantitative changes in autoantibodies in (NZB x NZW)F(1) female mice. These qualitative changes were manifested as a selective reduction in total or antigen-specific IgG2a antibody levels. CONCLUSIONS: The mechanisms through which MMF controls the development of SLE in (NZB x NZW)F(1) females is highly dependent upon immunosuppressor dose. Interestingly, lower dose MMF selectively reduced IgG2a antibody levels, suggesting that this dose may modulate T(H1) CD4+ activity.

Significance of age in the survival of diabetic patients after kidney transplantation.

BACKGROUND: In recent years acceptance of diabetic patients for renal replacement therapy has increased. Renal transplantation for Type I diabetic patients is widely accepted but the appropriate treatment for Type II diabetic patients is still a matter of dispute. Our study was done to determine whether the age of Type II diabetic patients constituted an additional risk factor. METHODS: We analyzed the outcome of renal transplantation in 56 diabetic patients, 31 Type I and 25 Type II diabetics (we excluded any who had combined kidney-pancreas transplants). We compared them with 51 non-diabetic patients who were transplanted because of end-stage renal failure due to nephrosclerosis and age-matched to type II diabetic patients. We assessed the one- and three-year patient and graft survival, the quality of renal function, the main complications and causes of mortality. RESULTS: The overall one- and three-year patient survival was 69% and 60% in Type II patients; 73% and 69% in Type I diabetes patients and 88% and 80% in patients with nephrosclerosis. The overall one- and three-year actuarial graft survival was 50% and 38% in patients with Type II disease and 58% and 50% in Type I diabetes, and 76% and 64% in nephrosclerosis. The main cause of graft loss in all groups was death (with functioning kidney) due to infections and cardiovascular complications. CONCLUSIONS: Diabetes itself is the most important variable in patients who have poor results after kidney transplantation. Increasing age increases slightly the risk for poor graft and patient survival. Both groups of diabetic patients have poorer results than controls but in this comparison age was an independent factor.