Retrospective Cohort Study
Copyright ©The Author(s) 2022. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Transplant. Sep 18, 2022; 12(9): 299-309
Published online Sep 18, 2022. doi: 10.5500/wjt.v12.i9.299
Vitamin D deficiency may predispose patients to increased risk of kidney transplant rejection
Semih Buyukdemirci, Ebru Gok Oguz, Sanem Guler Cimen, Hatice Sahin, Sertac Cimen, Mehmet Deniz Ayli
Semih Buyukdemirci, Department of Internal Medicine, Sağlık Bilimleri Universitesi, Ankara 65000, Altındağ, Turkey
Ebru Gok Oguz, Hatice Sahin, Mehmet Deniz Ayli, Department of Nephrology, Sağlık Bilimleri Universitesi, Ankara 65000, Altındağ, Turkey
Sanem Guler Cimen, Department of General Surgery, Sağlık Bilimleri Universitesi, Ankara 65000, Altındağ, Turkey
Sertac Cimen, Department of Urology, Sağlık Bilimleri Universitesi, Ankara 65000, Altındağ, Turkey
Author contributions: This study was conducted at Ankara Diskapi Research and Training Hospital, affiliated with the Health Sciences University of Turkey; the Departments of Internal Medicine, Nephrology, Urology, and General Surgery were involved in conducting the study; Oguz EG and Ayli MD designed the research; Buyukdemirci S and Cimen SG performed the research; Sahin H collected the data; Cimen S analyzed the data; Cimen SG wrote the paper.
Institutional review board statement: The study protocol was approved by the hospital’s ethical review committee (06.08.2018-no. 53/20) and was carried out in accordance with the Declaration of Helsinki and the Declaration of Istanbul.
Informed consent statement: All the patients provided written informed consent.
Conflict-of-interest statement: All the authors report no relevant conflicts of interest for this article.
Data sharing statement: We opt not to share our data, however if required for research purposes contact to the corresponding author is recommended.
STROBE statement: The authors have read the STROBE Statement-checklist of items, and the manuscript was prepared and revised according to the STROBE Statement-checklist of items.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:
Corresponding author: Sanem Guler Cimen, Doctor, FEBS, Adjunct Associate Professor, Department of General Surgery, Sağlık Bilimleri Universitesi, Güvenlik Caddesi No 87/6, Ankara 65000, Altındağ, Turkey.
Received: April 29, 2022
Peer-review started: April 29, 2022
First decision: May 12, 2022
Revised: June 1, 2022
Accepted: September 8, 2022
Article in press: September 8, 2022
Published online: September 18, 2022
Research background

Vitamin D deficiency is commonly diagnosed in patients with kidney transplantation. Deficiency rate remains high despite replacement therapies as per the Kidney Disease Improving Global Outcomes guidelines.

Research motivation

Vitamin D has immunomodulatory effects and vitamin D receptors can be found in various types of cells including T cells and dendritic cells. Its deficiency may predispose transplant recipients to rejection and chronic allograft nephropathy (CAN).

Research objectives

This study determined the association between the serum 25 (OH) vitamin D, biopsy-proven allograft rejection, and CAN rates.

Research methods

Retrospective clinical study involving adult kidney transplant recipients requiring graft biopsy due to declined function, hematuria, and proteinuria.

Research results

Vitamin D level was 9.7 ± 3.4 ng/mL in the rejection group vs 14.7 ± 7.2 in the non-rejection group; this difference was statistically significant (P = 0.003). In univariate regression analysis of risk factors affecting rejection, sex, serum vitamin D, phosphorus and albumin were found to have impact (P = 0.027, P = 0.007, P = 0.023, P = 0.008). In multivariate regression analysis, the same factors did not affect rejection.

Research conclusions

The serum 25 (OH) vitamin D level in kidney transplant recipients remained low. Although low serum vitamin D level emerged as a risk factor for rejection in univariate analysis, this finding was not confirmed by multivariate analysis. Prospective studies are required to appreciate the effect of serum vitamin D levels on allograft rejection.

Research perspectives

Kidney transplantation is the best treatment option for patients with terminal kidney failure. Successful transplantation prolongs longevity and significantly improves the quality of life. However, the long term success of kidney transplantation depends on preventing the chronic allograft dysfunction. Chronic allograft dysfunction is secondary to various immunological, infectious and drug related insults to the graft. Its prevention depends on close clinical follow-up and optimization of controllable variables, such as serum vitamin D levels.