Home About us Current issue Back issues Submission Instructions Advertise Contact Login   

Search Article 
  
Advanced search 
 
Saudi Journal of Kidney Diseases and Transplantation
Users online: 1340 Home Bookmark this page Print this page Email this page Small font sizeDefault font size Increase font size 
 


 
Table of Contents   
ORIGINAL ARTICLE  
Year : 2015  |  Volume : 26  |  Issue : 2  |  Page : 227-231
Albuminuria prediction of kidney function outcome in kidney transplant recipients


1 Department of Medicine, School of Medicine, University of Tabuk, Tabuk, Saudi Arabia
2 Department of Physiology, School of Medicine, University of Tabuk, Tabuk, Saudi Arabia

Click here for correspondence address and email

Date of Web Publication3-Mar-2015
 

   Abstract 

To investigate the association of albuminuria and kidney function outcome in kidney transplant recipients, we studied 161 kidney transplant recipients; 95 (59%) of them were males and the mean age of the patients was 46 ± 13 years (range 18-70 years). All the patients received allografts from living related kidney donors. The mean body mass index of the patients was 25 ± 4 kg/m 2 . Forty (25%) patients were diabetic and 72 (45%) patients were hypertensive. All the patients had glomerular filtration rate (iGFR) determination by ( 99m Tc-DTPA) clearance and albumiuria was assessed using the first voided morning urine samples. According to the results of albuminuria, the patients were subdivided into three groups: One group of 90 (56%) patients with normoalbuminuria (<30 mg albumin/g. creatinine), a second group of 52 (32%) patients with microalbuminuria (30-300 mg albumin/g. creatinine) and a third group of 19 (12%) patients with macroalbuminuria (>300 mg/g. creatinine). There was a significant increase in the time post transplantation in the patients with macroalbumiuria in comparison with microalbuminuria and normoalbuminuria (90 ± 28, 60 ± 22 and 18 ± 6 months, respectively), P <0.05. There was a significant decrease of iGFR in the macroalbumiuria group as compared with the microalbumiuria and normoalbuminuria groups (57 ± 24, 74 ± 20 and 74 ± 28 mL/min/1.73 m 2 , respectively), P <0.05. We conclude that there was an association between albuminuria and the status of the renal function in our transplant population, which may reflect renal injury due to proteinuria. Prospective studies are warranted to evaluate the effect of albuminuria on the prognosis of the kidney allografts.

How to cite this article:
El Minshawy O, El-Bassuoni E. Albuminuria prediction of kidney function outcome in kidney transplant recipients. Saudi J Kidney Dis Transpl 2015;26:227-31

How to cite this URL:
El Minshawy O, El-Bassuoni E. Albuminuria prediction of kidney function outcome in kidney transplant recipients. Saudi J Kidney Dis Transpl [serial online] 2015 [cited 2019 Oct 23];26:227-31. Available from: http://www.sjkdt.org/text.asp?2015/26/2/227/152397

   Introduction Top


Despite the improvement in both short- and long-term survival of renal allografts, many patients still experience progressive kidney dysfunction and graft failure. Data on the combined association of albuminuria and estimated glomerular filtration rate (eGFR) with renal transplant outcomes are limited. [1] Albuminuria is an important marker of allograft pathology and is associated with graft loss and cardiovascular disease. [2] The determinants of albuminuria in kidney transplant recipients are unlike those found in the general population. Acute rejection episodes occurred more commonly in kidney transplant recipients with microalbuminuria than in those with normalbuminuria, despite similar kidney function, suggesting that microalbuminuria may be a marker of sub-clinical renal lesions due to immunological etiology. [3]

The mechanisms of microalbuminuria in transplant patients are controversial, such as the intrarenal hemodynamic changes due to increased systemic blood pressure and capillary increased permeability at the glomerular level due to atherosclerotic vascular damage. [4] Experimental studies offer support to the concept that albuminuria is an indicator of endothelial dysfunction in the kidneys. [5]

Albuminuria is considered a marker for sub-clinical vascular damage that predisposes to future cardiovascular diseases and mortality. Lowering urinary albumin excretion reduces the risk of cardiovascular disease. [6] Furthermore, albuminuria might be a marker of decreased kidney function after kidney transplant, and measuring it may provide a prediction about the long-term renal outcome for kidney transplants. [7]

The aim of our study was to investigate the association of albuminuria with renal allograft function in transplant recipients.


   Materials and Methods Top


Our cross-sectional study included 161 kidney transplant recipients who survived for at least one year with functioning allografts. All the patients received allografts from living related kidney donors (LRRTs). The immunosuppressive treatment in 88% of the patients included prednisone 5-10 mg/day, a calcineurin inhibitor (cyclosporine or tacrolimus), and the antiproliferative agent mycophenolate mofetil (MMF), while the remaining 12% of the patients were on calcineurin-free protocols, which included prednisone 5-10 mg/day and MMF. One hundred and fifty-five (96%) patients received only one transplant, while six (4%) patients received two transplants. Forty (25%) patients were diabetic and 72 (45%) patients were hypertensive.

All kidney transplant recipients had glomerular filtration rate (iGFR) determination with ((99)m Tc-DTPA) clearance, as previously described. [8] The first voided morning urine samples were obtained on all the patients for the assessment of albuminuria by enzyme immunoassay and urinary creatinine (g/dL). [9] Venous blood was drained for laboratory assessment of blood urea nitrogen, creatinine, electrolytes, serum albumin, total cholesterol and triglycerides, using an automated clinical chemistry dimension ES and complete blood count using an automated cell coulter Sysmex NE.

Kidney transplant recipients were then subdivided into three groups: According to the results of albuminuria, the patients were subdivided into three groups: One group of 90 (56%) patients with normoalbuminuria (<30 mg albumin/g creatinine), a second group of 52 (32%) patients with microalbuminuria (30- 300 mg albumin/g. creatinine) and a third group of 19 (12%) patients with macroalbuminuria (>300 mg/g. creatinine).

Hypertension and blood pressure control was defined according to the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation and Treatment of High Blood Pressure (JNC 7 Report). [10] Dyslipidemia control was defined according to the Executive Summary of the Third Report of the National Cholesterol Education Program (NCEP) Expert Panel on Detection, Evaluation and Treatment of High Blood Cholesterol in Adults (Adult Treatment Panel III). [11]


   Statistical Analysis Top


Statistical analysis was performed by using commercially available statistical software (Minatab 15). Results for continuous variables are shown as the mean ± SD. The one-way ANOVA test was performed for quantitative comparison between groups. P-values <0.05 were considered to be significant.


   Results Top


[Table 1] shows the demographic and clinical characteristics of the study patients. Of the study patients, 95 (59%) patients were male, 88 (55%) patients were Egyptians and 73 (45%) patients were from the different Arab countries. The mean age of the patients was 46 ± 13 years (range 18-70 years). The mean body weight of the patients was 71 ± 8 kg, the body surface area was 1.8 ± 0.1 m 2 and the body mass index (BMI) was 25 ± 4 kg/m 2.
Table 1: Clinical and biochemical characteristics of all patients.

Click here to view


[Table 2] shows the comparison between the three sub-groups of the study patients. There was a significant increase in the time post transplantation in the patients with macroalbumiuria in comparison with microalbuminuria and normoalbuminuria (90 ± 28, 60 ± 22 and 18 ± 6 months, respectively), P <0.05. There was a significant decrease of iGFR in the macroalbumiuria group as compared with the microalbumiuria and normoalbuminuria groups (57 ± 24, 74 ± 20 and 74 ± 28 mL/ min/1.73 m 2 , respectively), P <0.05. There was no significant difference in iGFR between the controlled (12%) and the uncontrolled hypertensive patients.
Table 2: Clinical and biochemical characteristics of the three groups.

Click here to view


On further analysis of the normoalbumiuria group, we found iGFR <60 mL/min/1.73 m 2 in 58 patients and iGFR >60 mL/min/1.73 m 2 in 32 patients. There was a significant difference in serum albumin, hemoglobin and hematocrit as well as time post-transplant between both sub-groups. Moreover, there was a significant increase in time post-transplant in iGFR <60 mL/min/1.73 m 2 in 29 patients with microalbumiuria and iGFR >60 mL/min/1.73 m 2 in 23 individuals with microalbuminuria (70 ± 14 vs. 40 ± 10 months). The same finding was found in the macroalbumiuria group as the time post-transplant was significantly higher (95 ± 21 months) in patients with iGFR <60 mL/min/1.73 m 2 (13 patients) in comparison with 150 ± 17 months in patients with iGFR >60 mL/min/1.73 m 2 (six patients).


   Discussion Top


In our study, we found a significant difference between iGFR in macroalbuminuria versus microalbuminuria and normoalbuminuria kidney transplant groups. On further analysis, this difference was related to post-transplant time. This variation between the current study and other studies is probably due to difference in the age, duration of hypertension and coexistent renal disease in the study populations.

Perticone et al [12] concluded that albuminuria may contribute to renal impairment independently of inflammation and hemodynamic endothelial dysfunction in hypertensive subjects. Differences in the occurrence of microalbuminuria are, therefore, attributable to differing patient characteristics, urine sample collection and types of tests for proteinuria. [13] According to the recently modified renal disease guidelines [Kidney Disease outcome Quality Initiative (K/DOQI)/Kidney Disease: Improving Global Outcomes (KDIGO], [14] it is advisable to measure urinary albumin. In our study, we may extend the statement to recommend measuring albumniuria in the kidney transplant recipients.

Variation in the prevalence of microalbuminuria between the current study and that reported in other studies is mostly due to differences in the selection criteria, i.e. the severity of proteinuria, time post-transplant, age and race, besides the techniques used for the detection of albuminuria.

Damsgaard et al [15] reported a relatively high prevalence of microalbuminuria in a group of 216 elderly hypertensive patients, while Bigazzi and Bianchi [16] reported a high prevalence of microalbuminuria (40%) in a group of 123 unselected patients with essential hypertension. These results are in agreement with the results of our current study.

We conclude that there was an association between albuminuria and the status of the renal function in our transplant population, which may reflect renal injury due to proteinuria. Prospective studies are warranted to evaluate the effect of albuminuria on the prognosis of the kidney allografts.

Conflict of interest: None declared.

Dr. Osama El Minshawy and Dr. Eman El-Bassuoni are both on sabbatical leave from El-Minia University School of Medicine, El-Minia, Egypt.

 
   References Top

1.
Hernández D, Pérez G, Marrero D, et al. Early association of low-grade albuminuria and allograft dysfunction predicts renal transplant outcomes. Transplantation 2012;93:297-303.  Back to cited text no. 1
    
2.
Akbari A, White CA, Shahbazi N, Booth RA, Hiremath S, Knoll GA. Spot urine protein measurements: Are these accurate in kidney transplant recipients? Transplantation 2012;94: 389-95.  Back to cited text no. 2
    
3.
Halimi JM, al-Najjar A, Buchler M, et al. Microalbuminuria in hypertensive, non-proteinuric renal transplant recipients: Role of previous acute rejection episodes and sodium intake. Transplant Proc 2002;34:801-2.  Back to cited text no. 3
    
4.
Erley CM, Risler T. Microalbuminuria in primary hypertension: Is it a marker of glomerular damage? Nephrol Dial Transplant 1994;9:1713-5.  Back to cited text no. 4
    
5.
Perticone F, Maio R, Tripepe G, Sciacqua A, Mallamaci F, Zoccali C. Microalbuminuria, endothelial dysfunctionand inflammation in primary hypertension. J Nephrol 2007;20 Suppl 12:S56-62.  Back to cited text no. 5
    
6.
Uchida J, Machida Y, Iwai T, et al. Low-grade albuminuria reduction with angiotensin II type 1 receptor blocker in renal transplant recipients. J Nephrol 2011;24:515-21.  Back to cited text no. 6
    
7.
Nauta FL, Bakker SJ, van Oeveren W, et al. Albuminuria, proteinuria, and novel urine biomarkers as predictors of long-term allograft outcomes in kidney transplant recipients. Am J Kidney Dis 2011;57:733-43.  Back to cited text no. 7
    
8.
El-Minshawy O, Saber R, Osman A. 24 Hour creatinine clearance is unreliable for estimation of GFR in different stages of chronic kidney disease. Saudi J Kidney Dis Transpl 2010;21: 686-93.  Back to cited text no. 8
[PUBMED]  Medknow Journal  
9.
Magnotti RA, Stephens GW, Ragers RK, Resa A. Microplate measurement of urinary albumin and creatinie. Clin Chem 1989;35:1371-5.  Back to cited text no. 9
    
10.
Chobanian AV, Bakris GL, Black HR, et al; National Heart, Lung, and Blood Institute Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure; National High Blood Pressure Education Program Coordinating Committee. The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure: The JNC 7 report. JAMA 2003;289:2560-72.  Back to cited text no. 10
    
11.
National Cholesterol Education Program (NCEP) Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (Adult Treatment Panel III): Third Report of the National Cholesterol Education Program (NCEP) Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (Adult Treatment Panel III) final report. Circulation 2002;106: 3143-421.  Back to cited text no. 11
    
12.
Perticone F, Maio R, Tripepe G, Sciacqua A, Mallamaci F, Zoccali C. Microalbuminuria, endothelial dysfunction and inflammation in primary hypertension. J Nephrol 2007;20 Suppl 12:S56-62.  Back to cited text no. 12
    
13.
Pontremoli R, Sofia A, Ravera M, et al. Prevalence and clinical correlates of microalbuminuria in essential hypertension: The MAGIC Study. Microalbuminuria: A Genoa Investigation on Complications. Hypertension 1997;30: 1135-43.  Back to cited text no. 13
    
14.
Levey AS, Eckardt KU, Tsukamoto Y, et al. Definition and classification of chronic kidney disease: A position statement from Kidney Disease: Improving Global Outcomes (KDIGO). Kidney Int 2005;67:2089-100.  Back to cited text no. 14
    
15.
Damsgaard EM, Froland A, Jorgensen OD, Mogensen CE. Microalbuminuria as predictor of increased mortality in elderly people. Br Med J 1990;300:297-300.  Back to cited text no. 15
    
16.
Bigazzi R, Bianchi S. Microalbuminuria as a marker of cardiovascular and renal disease in essential hypertension. Nephrol Dial Transplant 1995;10 Suppl 6:10-4.  Back to cited text no. 16
    

Top
Correspondence Address:
Dr. Osama El Minshawy
Department of Medicine/Nephrology, School of Medicine, University of Tabuk, Tabuk
Saudi Arabia
Login to access the Email id


DOI: 10.4103/1319-2442.152397

PMID: 25758867

Rights and Permissions



 
 
    Tables

  [Table 1], [Table 2]



 

Top
   
 
 
    Similar in PUBMED
    Search Pubmed for
    Search in Google Scholar for
    Email Alert *
    Add to My List *
* Registration required (free)  
 


 
    Abstract
   Introduction
    Materials and Me...
   Statistical Analysis
   Results
   Discussion
    References
    Article Tables
 

 Article Access Statistics
    Viewed2833    
    Printed32    
    Emailed0    
    PDF Downloaded507    
    Comments [Add]    

Recommend this journal