New aspects of posttransplant nephrotic syndrome: clinicopathologic correlations with outcomes

Proteinuria 1 year after renal transplantation is associated with impaired graft survival in children

BACKGROUND

Proteinuria is a common manifestation of chronic kidney disease (CKD), and there is a high incidence of CDK and its complications following renal transplantation. However, little data are available on the association between proteinuria and graft/patient survival in the paediatric transplant population. The primary aim of this study was to investigate the associations between posttransplant proteinuria and graft/patient survival in children after renal transplantation.

METHODS

In this retrospective study, we screened all 91 children receiving renal allografts at a single institution between 1997 and 2007. The inclusion criteria were a functioning graft at 1 year posttransplant, data availability and no recurrence of focal-segmental glomerulosclerosis. The final cohort included 75 patients. Proteinuria was considered to be pathologic if the urinary protein/creatinine ratio was >30 mg/mmol. Donor and recipient characteristics, data on proteinuria, estimated glomerular filtration rate (eGFR) and rejection episodes were analysed. The most recent of the biopsies performed during the follow-up after 1 year posttransplant were analysed separately in the proteinuric group and the non-proteinuric group.

RESULTS

Proteinuria at 1-year posttransplant was pathologic in 35 % of patients. The 5-year graft survival rate was significantly lower in the proteinuric group than in the non-proteinuric group (77 vs. 100 %; p < 0.001). Proteinuria at 1 year posttransplant was associated with reduced long-term graft survival independent of other risk factors, including decreased eGFR or episodes of acute corticosensitive and corticoresistant rejection. The most frequent histologic finding in the proteinuric group was chronic rejection. There was no significant difference in the 5-year patient survival rate between the proteinuric group and the non-proteinuric group.

CONCLUSION

This study emphasizes the importance of proteinuria as a prognostic factor of renal allograft survival in children.

Posttransplantation glomerulonephritis: risk factors associated with kidney allograft loss

AIM OF THE STUDY

Chronic glomerulonephritis (GN) is reported as a common cause of late kidney allograft loss. The aim of this study was to identify risk factors associated with kidney allograft loss in the course of posttransplantation GN.

PATIENTS AND METHODS

The study analyzed 75 kidney allograft recipients with biopsy-confirmed posttransplantation GN, including 27 cases of immunoglobulin (Ig)A nephropathy (IgAN), 30 of membranous GN (MGN), 6 of mesangiocapillary GN (MCGN); and 12 of focal segmental GN (FSGS). The risk factors for kidney allograft loss, defined as dialysis reintroduction after GN onset, were identified through are historical cohort study.

CLINICAL FINDINGS

After the onset of posttransplantation GN, the median time to dialysis introduction was 46 months. The risk factors for kidney allograft loss were as follows: male gender (hazard ratio [HR] = 1.92; 95% confidence intervall [CI] 1.0-3.70; P = .052), initial unsatisfactory kidney function (HR = 1.86 per 1 mg/dL serum creatinine increment; 95% CI 1.0-3.46; P < .05), graft dysfunction at diagnosis (HR = 1.65 per 1 mg/dL serum creatinine increment; 95% CI 1.32-2.07; P < .001), nephrotic syndrome (HR = 2.3; 95% CI 1.13-4.99; P < .05) late-onset GN (HR = 1.1 per each additional year of observation, 95% CI 1.0-1.21; P < .05), and MPGN as a type of GN. Enhanced immunosuppression increased and ACEI and/or statin treatment decreased the risk of return to dialysis, respectively: HR = 1.56, 95% CI 0.76-3.18, P = .22; HR = 0.39, 95% CI 0.16-0.98, P = .0037; and HR = 0.367, 95% CI 0.15-0.88, P = .025.

CONCLUSIONS

Identification of risk factors can help discover patients who will have a faster progression to kidney allograft loss due to GN. In posttransplantation GN, statins and/or ACEI should be prescribed, if there are no contraindications.

Prognostic factors associated with poor graft outcomes in renal recipients with post-transplant glomerulonephritis

BACKGROUND

Little data are available concerning post-transplantation glomerulonephritis (PTx-GN) and its prognostic factors associated with graft outcomes.

METHODS

We retrospectively evaluated patients with de novo and recurrent PTx-GN to identify the factors associated with their negative impact on graft and patient outcomes. PTx-GN was diagnosed in 55 patients, wherein 17 (31%) had recurrent glomerulonephritis (GN) and 16 (29%) had de novo.

RESULTS

Our enrolled population consisted of 34 +/- 13.7-yr-old male patients (72%), on hemodialysis for a median of 18 months (0-204) and mainly grafted from living donors (76%). The median onset time of proteinuria and hematuria was 50 d (10-2160) and 30 d (4-1170), respectively. One-yr graft survival rates after PTx-GN diagnosis was 64%. The most frequent de novo GN was membranous GN (26%), while focal segmental glomerulosclerosis was the most frequent recurrent GN (41%), with a very early onset (median of three months). One-yr graft survival was better in the recurrent disease than in the de novo patients, 76% vs. 55% (p = 0.24). The best predictor factors that correlated with graft survival were: proteinuria <3.5 g [relative risk (RR) = 0.24, p = 0.017], serum creatinine below 2.0 mg/dL (RR = 0.06, p = 0.016) at the time of biopsy and the use of angiotensin-converting enzyme inhibitors (ACEI) (RR = 0.12, p = 0.005). The use of ACEI markedly improved one-yr graft survival rates (92% vs. 47%, p < 0.001).

CONCLUSION

PTx-GN has a strong negative impact on kidney graft survival. De novo GN appears to have a poorer prognosis than the recurrent type. Patients who used ACEI showed a better survival rate in the follow-up.

Therapeutic plasma exchange as a nephrological procedure: A single-center experience

In the United States, therapeutic plasma exchange (TPE) is both performed and requested by a wide range of services, often on an empiric basis (before a diagnosis is established). Whether empiric therapy is beneficial has not been established. Patients were identified from an electronic procedure log that included those patients who received plasmapheresis at Walter Reed Army Medical Center from 1996 to 2003. The clinical indications, referring service, and outcomes (including deaths) that occurred were tabulated. Between March 1997 and August 2003, 568 TPE treatments were performed in 54 patients. The majority of the diagnoses were either neurologic (48%) or hematologic (37%). Thirty-three patients (61%) received TPE for a Category I indication. Twelve cases were performed empirically (without an established diagnosis) at the request of the referring service, most (7) performed for presumed thrombotic thrombocytopenic purpura (TTP). Almost 80% of patients required central venous catheters for treatment. Twelve patients (22%) experienced a major complication including death, and six patients (11%) died. Of the patients who died, 5 (83%) were treated empirically versus one death (17%) among patients not treated empirically, P < 0.001 by Chi Square. Only one of the seven patients treated empirically for TTP died, however. In logistic regression analysis, empiric treatment was the only factor independently associated with death, adjusted odds ratio, 34.2, 95% CI, 3.4, 334.8, P = 0.003. The most common indication for TPE was neurological disease, which also accounted for the highest proportion of complications. With the exception of presumed TTP, performing TPE in the absence of a confirmed diagnosis was not beneficial.