The incidence of chronic kidneydisease has  increased markedly  in recent years, with these serious complications, especially in the terminal stage, requiring treatment with dialysis and kidney transplantation (1). The latter, made from a living donor, remains the ideal treatment for IRCT;  It offers a better quality of life for patients (2).  S he realization from a living donor is based on strict and well-defined selection criteria,   which concern both the donor and the recipient. One of the main criteria is the  evaluation of the glomerular filtration rate (GFR) before donation, this is done by different evaluation methods from one country to another: GFR measurement methods,  isotopic methods and  GFR estimation methods by specific equations (4,5).  In our country, the only transplant that is done is from a  living donor, hence the interest  of   a good evaluation of the donor (2,3). The eGFR is calculated by the MDRD and CKD-EPICr equations according to the habits of the transplant teams without having a clear idea of the superiority of one over the other. The objective  of our study is the evaluation of GFR in pre- and post-donation donors, using cystatin C and the equations CKDEPIcyst and CKDEPICr-cyst.

Cystatin C (cyst C) has been known since 1961. The two techniques for the determination of cystatin C are: immuno-nephelometry and immuno-turbidimetry. The sample can be stored for at least 48 hours at room temperature, 7 days at + 4 ° C and several months or even several years at - 80 C °. Several cycles (3-10) of freeze-thaw can be done. Blood is collected on either heparin or EDTA(6,7,8,9,10).

Recent guidelines from KDIGO 2012(11) suggest the use of cyst C to validate CKD in patients considered as such on the basis of a GFR < 60>

Problematic:

The eGFR before authorizing donation requires a rigorous assessment, to allow the donor to be selected safely. Recommendations suggest measuring GFR by reference methods or measuring by isotopic method. The unavailability of these techniques and the practical difficulty of their realization, have led to the development of other methods such as the online calculator. In our country, we use creatinine equations, but these equations are still insufficient. Lack of access to the above methods; which led us to use other equations based on the combination of creatinine and cystatin C. The objective of our study is the usefulness  of  hepatitis C in the evaluation of GFR by the mixed CKD-PPE equation in living donors before  donation and after kidney donation, to select the donor in the absence of reference measurement methods.

It is a  prospective follow-up, longitudinal,  descriptive and analytical, multicenter study involving three nephrology  teams  . We recruited 55 couples (55  donors and 55 recipients), then we excluded 04 recipients because of their ages, note that: The sample size is calculated: n = P (1-P) X (Z/d) 2.P: prevalence: 1,025%. Z: 1.96 with an alfa risk of 5%. D: accuracy: 3%.n: 43.3. 

After rigorous interrogation and clinical examination. eGFR was calculated using equations (MDRD, CKD-EPICr, CKD-EPICyst and CKD-EPICr-cyst) using an online calculator   "06 GFR equations" before  donation, 3 months and 6 months after donation.

Results:

In our study (Table 01) we have 55 donors, among them 53.6% women, the average age is: 47.8±11.78 years, the average BMI is 25.56±2.94 kg/m² and donors are classified according to age with a Cut-off: 40 years:  

30 donors (representing 75% of donors over 40 years of age) have a BMI between 25-29.9 kg/m² donation they are overweight.

 3 donors out of 55 have a BMI >30 kg/m² considered obese, two of them are over 40 years old 

The different means of the eGFR calculated by the 04 equations (MDRD; CKDEPICr, CKDEPIcyst, CKDEPICr-cyst) which are: 103.67±28.2;101.15±18.77;99.58±21.25 and 98.07±19.53 respectively. By the ANOVA test: there is no significant difference between the means of GFR by the 04 equations before donation.52 donors out of 55 are normo tense and 03 hypertensive donors balanced under monotherapy without visceral impact, which represents 5.4% of all donors.

The mean cystatin C prior to donation was: 0.81±0.21mg/l (Table 01).  There is a significant difference between the pre-donation means of creatinine and cystatin C by sex, the hourshad  higher means of creatinine  and cystatin C  than women respectively: 7.13±1.91 and 8.52±1.70 with a P Less-than sign 0.01 and cystatin C values 0.92±0.19 and 0.71±0.18 with a P Less-than sign0.01. There is no significant difference by age, hypertension, and microalbuminuria.

With regard to the eGFR averages calculated by the different equations: there is a highly significant difference between the age-specific eGFR averages for a cut-off: 40 years calculated by CKD-EPICr-cyst and CKD-EPIcyst, donors aged less than 40 years had higher averages compared to donors over 40 years of age with a P of 0.002. While the eGFR averages  that are calculated by MDRD there is no significant difference. Also there is a significant difference between eGFR averages by sex

Table 01:

Table No.:02

The determination of cystatin C and the use of mixed CKDEPIis essential for the proper assessment of GFR. This equation is able to assess GFR in  the closest way to actual GFR because it is based on two endogenous markers. It recovered 08 donors out of 18 who were rejected for donation by the MDRD without any nephrological biological or radiological abnormalities. The CKD-PPE Cr-cyst equation has proven its effectiveness in readjusting the GFR assessment by the MDRD equation for a donation threshold (Cut-off: 90 ml.mn.1.73m²). It acceptedmore donors than MDRD, with good quality graft and remaining kidney function in the donor

Collaborators:

Kidney transplant teams in 03 kidney transplant centers at 03 hospitals:

Nephrology department at their t,Pr RAYANE, and Mazari at the University Hospital of Nafisa Hamoud (Ex Parnet): nephrologists, general practitioners The vascular surgeons of the vascular surgery department of the EHS of Maouche Mohand Amokrane..The renal transplant team of the nephrology department of the Central Hospital of the Army headed by Professor BOULAHIA and all the medical and paramedical staff, as well as the urological surgeons and vascular surgeons at their head Pr GAACHI. Thekidney transplant team of the CHU Batna: at their head Pr BOUGROURA and Pr Missoum with the entire medical team: general practitioners and nephrologists.As well as the surgical team headed by Professor Chaouche, and Professor Ourlent.

There is a correlation between the GFR calculated by MDRD and CKD mixed PPE (R=0, 6, P<0 R²=0.409)>

The concordance between the different equations of the calculation of GFR before donation in donors, calculated by the two equations MDRD and mixed ckdepi: