Chronic graft loss and death in patients with post-transplant malignancy in living kidney transplantation: a competing risk analysis

Longitudinal Serum Creatinine Levels in Relation to Graft Loss Following Renal Transplantation: Robust Joint Modeling of Longitudinal Measurements and Survival Time Data

BACKGROUND

Chronic kidney disease (CKD) is a major public health problem that may lead to end-stage renal disease (ESRD). Renal transplantation has become the treatment modality of choice for the majority of patients with ESRD. It is therefore necessary to monitor the disease progression of patients who have undergone renal transplantation. In order to monitor the disease progression, the continuous assessment of kidney function over time is considered.

OBJECTIVES

This study aimed to investigate the etiological role of recipient characteristics in serum creatinine changes within the follow-up period and in relation to the graft failure risk, as well as to evaluate whether or not the serum creatinine level represents an indicator of graft failure following renal transplantation.

METHODS

This retrospective cohort study was conducted at the department of nephrology, Baqiyatallah Hospital, Baqiyatallah University of Medical Sciences, between April 2005 and December 2008. The study involved 413 renal transplantation patients. The primary outcomes were the determination of the serum creatinine levels at each attendance and the time to graft failure. Robust joint modeling of the longitudinal measurements (serum creatinine level) and time-to-event data (time to graft failure) were used for the analysis in the presence of outliers in the serum creatinine levels. The data analysis was implemented in WinBUGS 1.4.3.

RESULTS

There was a positive association between the serum creatinine level and graft failure (HR = 5.13, P < 0.001). A one unit increase in the serum creatinine level suggests an increased risk of graft failure of up to 5.13 times. The serum creatinine level significantly decreased over time (95% CI: (-1.58, -1.08)). The recipient's age was negatively associated with the serum creatinine level (95% CI: (-0.02, -0.001)).

CONCLUSIONS

Graft failure is more likely to occur in patients with higher serum creatinine levels.

Longitudinal Assessment of Serum Creatinine Levels on Graft Survival After Renal Transplantation: Joint Modeling Approach

Background

Chronic kidney disease (CKD) is a major public health problem. The eventual outcome of CKD is end-stage renal disease (ESRD). Early diagnosis and proper management play an important role in preventing CKD progression to ESRD. Dialysis and kidney transplantation are the only treatment options available for patients suffering from ESRD.

Objectives

This study was designed to investigate the etiological role of recipient and donor characteristics on serum creatinine changes within the follow-up period, graft failure risk, and the impact of longitudinal serum creatinine levels on graft survival after renal transplantation.

Patients and Methods

This study was carried out at the department of nephrology, Baqiyatallah hospital, Baqiyatallah University, Tehran, Iran, between April 2005 and December 2008. During that time period, 461 patients who had undergone renal transplantation were entered in the current study. Time to graft loss and serum creatinine levels at each visit were the primary data gathered for the study. A joint modeling of survival and longitudinal nonsurvival data was used to assess the association between the two processes and investigate the influential factors.

Results

Median follow-up time was 6.80 months. A linear decreasing trend in serum creatinine level over time was found (P < 0.001). The results showed a positive correlation between serum creatinine levels and risk of graft failure (P < 0.001).

Conclusions

The major finding of this study is that one unit increase in serum creatinine level suggests an increased risk of graft failure of up to four times.

Changes in Exfoliative Cell of Oral Mucosa in Kidney Transplant Patients

OBJECTIVES

The aim of this study was to investigate quantitative cytologic changes in oral mucosal smears collected from kidney transplant patients by modern stereologic methods.

METHODS

We enrolled 32 kidney transplant patients. Smears were obtained from the buccal mucosa transplant patients before and 12 months after kidney transplantation. Smears from each individual were stained using the Papanicolaou method and were analyzed using a stereological method.

RESULTS

Statistically, the nuclear volumes and cytoplasmic volumes in the cells of buccal mucosa were markedly higher after kidney transplantation (P < .05). There was a decreased positive cell density in the oral epithelial cells after kidney transplantation compared with before renal transplantation (P < .05).

CONCLUSIONS

These findings suggest that there are alterations in the oral epithelial cells after kidney transplantation, which are detectable by microscopy and cytomorphometry.