Kidney Week

Abstract: TH-PO175

Phosphate levels: Early Determining Factors and Influence in Long Term Graft Outcome in a Cohort of Renal Transplanted Patients

Session Information

• Transplantation: Cardiovascular and Metabolic Diseases
  October 25, 2018 | Location: Exhibit Hall, San Diego Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Transplantation

• 1802 Transplantation: Clinical

Authors

• Alfieri, Carlo M., Fondazione IRCCS Ca' Granda Ospedale Policlinico Milan, Milan, Italy

Carlo M. Alfieri,

• Gandolfo, Maria Teresa, Fondazione IRCCS Ca' Granda Ospedale Policlinico Milan, Milan, Italy

Maria Teresa Gandolfo,

• Cresseri, Donata, Fondazione IRCCS Ca' Granda Ospedale Policlinico Milan, Milan, Italy

Donata Cresseri,

• Campise, Mariarosaria, Fondazione IRCCS Ca' Granda Ospedale Policlinico Milan, Milan, Italy

Mariarosaria Campise,

• Binda, Valentina, Fondazione IRCCS Ca' Granda Ospedale Policlinico Milan, Milan, Italy

Valentina Binda,

• Ikehata, Masami, Fondazione IRCCS Ca' Granda Ospedale Policlinico Milan, Milan, Italy

Masami Ikehata,

• Tripodi, Federica, Fondazione IRCCS Ca' Granda Ospedale Policlinico Milan, Milan, Italy

Federica Tripodi,

• Tangredi, Marianna, Fondazione IRCCS Ca' Granda Ospedale Policlinico Milan, Milan, Italy

Marianna Tangredi,

• Malvica, Silvia, Fondazione IRCCS Ca' Granda Ospedale Policlinico Milan, Milan, Italy

Silvia Malvica,

• Messa, Piergiorgio, Fondazione IRCCS Ca' Granda Ospedale Policlinico Milan, Milan, Italy

Piergiorgio Messa,

Background

Renal transplantation (RTx) only partially corrects certain metabolic alterations, especially in mineral metabolism (MM). We aim to examine the effect of RTx during the 1^st year of RTx on P levels, exploring the factors related and influencing P levels after 1 month (T1) and 12 months (T2) of RTx. The impact on long term graft outcome of 1^st year average P levels (P-avr) will also be explored.

Methods

In 132 RTx pts (age: 48[37;58] yrs – 87 males), up to the 476 transplanted in our unit between 2006 and 2015, clinical parameters, blood and urinary samples were collected at T1 and T2. In addition, in all the patients intact FGF23 (iFGF23) was tested at T1 and T2. Median follow up (FU) was 5[3-9] yrs.

Results

84% percent of patients received a kidney from a deceased donor; 68% and 23% of patients were treated with haemodialysis and peritoneal dialysis before RTx. Dialysis vintage was 49[27-64] mths. Cold ischemia time was 13[11-16]h. MM parameters at T1 were: Ca 9.7[9.3-10.2]mg/dL, iPTH 68[42-114]pg/mL, ALP 94[72-127]U/L, 25OHVitD 12[8-17]ng/mL. Between T1 and T2, an increase of P levels was noted (T1:2.3[1.9-2.8]mg/dL – T2 3.1[2.7-3.6] mg/dL, p<0.001). iFGF23 was reduced (T1: 80[6-1360] pg/mL– T2 62[14-489] pg/mL, p=0.01). P-avr was 2.7[2.3-3.1]mg/dL. Thirty-five percent and 11% of patients were treated with active and native vitamin D during the first year of RTx.
In multivariate analysis, T1-iFGF-23, T2-ALP and T2-Ca resulted the most influencing parameters of T1-P, T2-P and P-av (p=0.009, p=0.03 and p=0.002 resp.). No relationship between T2-P and T2-iFGF23 as like as between P-av and renal function was found. No influence of immunosuppressive therapy was found.
During FU, 8 patients restarted dialysis (D+). D+ were different to those patients with functioning graft only for higher T2-PTH (p=0.01) and P-av (p<0.0001). In Cox and ROC curve analysis, P-av was the best predicting and discriminatory factor for graft loss (Cox: p<0.0001; ROC: AUC 0.71±0.10– p=0.04).

Conclusion

Our data confirm that RTx has an impact to MM from the beginning, and that P levels are influenced by different factors at T1 and T2. However, independently to renal function, P-av might influence long-term graft outcome.