New research published in Journal of Clinical and Translational Research identified vitamin D deficiency as a possible risk factor for the susceptibility of kidney transplant patients to transplant rejection.
Through recent research, the regulatory potential of vitamin D on the immune system and its link with autoimmune diseases has become clearer. Researchers are now becoming interested in if vitamin D plays a role in immuno-compromised organ transplant patients and the increased risk of acute cellular rejection (ACR).
ACR is when the transplanted tissue is rejected by the recipient’s immune system. It is a major complication after kidney transplantation. The long term graft success after treatment of ACR is not promising and remains a major risk factor for chronic transplant dysfunction.
Research to date on vitamin D and ACR has been limited to observational studies and the results have been inconsistent.
In a new study, scientists from Weill Cornell Medical College, New York, conducted a retrospective analysis of kidney transplant recipients, using the Endocrine Society Consensus guidelines which define vitamin D deficiency as a level lower than 20 ng/ml in order to reveal a potential relationship.
The researchers identified 1,211 kidney transplant recipients, of which 351 had circulating vitamin D levels measured within the first 30 days after transplantation was performed at Weill Cornell Medical Center in New York.
Furthermore, 133 patients who were vitamin D deficient were prescribed varying amounts of vitamin D2 or D3 supplements within the first 90 days by their physician.
The researchers wanted to investigate possible correlations between post-transplant vitamin D status, the incidence of ACR during the first year of transplantation, and kidney function after 1 year, using the incidence of biopsies to confirm ACR.
Here’s what the researchers found:
- 27 of the 351 patients developed ACR, and the incidence was significantly higher in those who were vitamin D deficient (P=0.04).
- Vitamin D deficiency was an independent risk factor for ACR (P=0.02).
- Vitamin D status was not associated with post-transplant viral infections or kidney function 12 months post-transplantation.
The researchers concluded:
“The findings from this study that vitamin D deficiency is associated with ACR and that supplementation with vitamin D may reduce this risk suggest that issues related to screening vitamin D levels in the post transplantation period and treatment in those found to be vitamin D deficit require evaluation in properly designed clinical trials.”
The research conducted shows an interesting correlation between vitamin D levels and increased risk of ACR in kidney transplant patients. However it is disappointing that no associations were found in regards to post-transplant diseases. One possible reason for this may be due to the small number of events occurring in this study cohort.
Continual research using consistent vitamin D supplement dosage in larger populations should help address the limitations of this study and may potentially inform future screening procedures and supplementation programs for kidney transplant recipients.