Vitamin D Levels After Kidney Transplantation and the Risk of Cytomegalovirus Infection

Prevalence of vitamin D deficiency and impact on clinical outcomes after kidney transplantation: a systematic review and meta-analysis

CONTEXT

The prevalence of vitamin D deficiency (VDD) and its impact on clinical outcomes after kidney transplant (KT) remain poorly defined.

OBJECTIVES

We conducted a meta-analysis to evaluate the impact of early VDD on clinical outcomes after KT.

DATA SOURCES

Electronic databases (PubMed, Embase, Web of Science, and The Cochrane Library) were systematically searched for eligible publications up to April 30, 2020.

DATA EXTRACTION

Relative risk was presented as hazard ratios (HRs) or odds ratios (ORs) and 95%CIs for dichotomous outcomes. Mean difference (MD) and 95%CIs were presented for continuous outcomes.

RESULTS

A total of 28 studies (13 prospective and 15 retrospective) were included. VDD was common early after KT, with a prevalence of 52% (95%CI: 41%-64%) at transplant, 34% (95%CI: 17%-51%) at 3 months, and 23% (95%CI: 10%-35%) at 6 months. Early VDD was associated with higher mortality rate after KT (HR, 1.56; 95%CI: 1.32-1.84; P < 0.001). In addition, early VDD led to higher risk of bacterial infection (OR, 1.82; 95%CI: 1.40-2.36; P < 0.001), BK polyomavirus infection (OR, 2.11, 95%CI: 1.23-3.61; P = 0.006), and cytomegalovirus infection (OR, 1.69; 95%CI: 1.24-2.31; P = 0.001). Early VDD increased the risk of acute rejection as well (HR, 2.28; 95%CI: 1.57-3.30; P < 0.001). Recipients with early VDD had lower estimated glomerular filtration rates (mean difference: -5.06; 95%CI: -7.28 to 2.83 mL/min; P < 0.001). Sensitivity analyses showed good stability of the pooled results.

CONCLUSION

VDD was common early after KT and associated with higher risk of death and adverse outcomes.

Vitamin D Receptor and Vitamin D Binding Protein Gene Polymorphisms Are Associated with Renal Allograft Outcome

Vitamin D deficiency has adverse effects on renal allograft outcomes, and polymorphisms of genes encoding vitamin D-binding protein (VDBP) and vitamin D receptor (VDR) are defined to play a role in these conditions. The goal of the current investigation was to evaluate the connection between those polymorphisms with acute rejection, viral infection history, and recipients’ vitamin D status. In this study, 115 kidney transplant recipients and 100 healthy individuals were included. VDR polymorphisms including FokI (rs2228570), Apal (rs7975232), BsmI (rs1544410), as well as VDBP (rs7040) polymorphisms were studied using high resolution melting (PCR-HRM) analysis among the studied groups. The frequency of G allele in Apal rs7975232 polymorphism in the kidney transplant recipients was 0.63 times lower than healthy individuals (p = 0.026). Further, the G allele frequency in VDBP rs7040 polymorphism was significantly lower in patients with allograft rejection (p = 0.002). Considering the incidence of viral infection, significant differences were identified between the frequencies of VDR FokI (OR = 2.035; 95% CI 1.06–2.89, p = 0.030) and VDBP rs7040 (OR = 0.40; 95% CI 0.24–0.67, p < 0.001) T alleles in the studied groups. Moreover, the VDBP rs7040 GG genotype distribution was low in the recipients with a history of viral infection (p = 0.004). VDR (FokI) and VDBP (rs7040) alleles and their genotype distribution are significantly associated with allograft outcomes including allograft rejection and viral infection in the studied population.

Association of vitamin D status with liver and kidney disease: A systematic review of clinical trials, and cross-sectional and cohort studies

Abstract. Background: Vitamin D deficiency (VDD) is a major public health problem. There are few comprehensive systematic reviews about the relationship between Vitamin D status and liver and renal disease in Iran.

Methods: We systemically searched the following databases: Web of Science; PubMed; Cochrane Library; Scopus; Science Direct; Google Scholar and two Iranian databases (Scientific Information Database (SID) and IranMedex) up until November 2017 to identify all randomized control trials (RCTs), case control, cross-sectional and cohort studies investigating the association between vitamin D and any form of liver or kidney disease.

Results: Vitamin D insufficiency, or deficiency (VDD), is highly prevalent in Iran, reports varying between 44.4% in Isfahan to 98% in Gorgan. There is also a high prevalence of VDD among patients with liver or kidney disease, and the administration of vitamin D supplements may have beneficial effects on lipid profile, blood glucose, liver function and fatty liver disease, and bone health. Low serum vitamin D levels are related with abnormalities in these laboratory and clinical parameters.

Conclusion: VDD is prevalent in patients with chronic liver or renal disease in Iran. There appear to be several beneficial effects of vitamin D supplementation in vitamin D deficient patients with liver or kidney disease.

Vitamin D Deficiency or Supplementation and the Risk of Human Herpesvirus Infections or Reactivation: A Systematic Review and Meta-analysis

BACKGROUND

Vitamin D may protect against respiratory virus infections, but any association with herpesviruses is unclear.

METHODS

We undertook a systematic review of vitamin D deficiency or supplementation and the risk of 8 human herpesviruses. Six databases and 4 gray literature databases were searched for relevant cohort studies, case-control studies, and clinical trials.

RESULTS

Ten studies were included, all conducted among immunosuppressed patients. There was no evidence that vitamin D deficiency is associated with cytomegalovirus (CMV) disease (pooled risk ratio, 1.06; 95% CI, 0.66-1.7), herpes zoster after transplantation (1 study), or HHV-8 among HIV patients (1 study). Vitamin D supplementation may decrease herpes zoster among hemodialysis patients (1 study) or CMV disease after renal transplantation (1 study), but supplementation was not associated with reduced EBV viral load among multiple sclerosis patients (1 study).

CONCLUSIONS

Any association between vitamin D and herpesviruses remains inconclusive. Further studies in the general population are needed.

Association between 25(OH) vitamin D and graft survival in renal transplanted children

BACKGROUND

In children, vitamin D deficiency is common after renal transplantation. Besides promoting bone and muscle development, vitamin D has immunomodulatory effects, which could protect kidney allografts. The purpose of this study was to assess the association between vitamin D status and the occurrence of renal rejection.

METHODS

We studied a retrospective cohort of 123 children, who were transplanted at a single institution between September 2008 and April 2019. Patients did not receive vitamin D supplementation systematically. In addition, factors influencing vitamin D status were analyzed using univariate and multivariate analyses.

RESULTS

Median 25-hydroxy-vitamin D (25-OH-D) concentration was close to reference values at the time of transplantation (30 ng/mL (min-max 5-100)), but rapidly decreased within the first 3 months to 19 ng/mL (min-max 3-91) (P < .001). The overall acute rejection rate was 7%. The clinical rejection rate (5% vs 9%), subclinical rejection (12% vs 36%), and borderline changes (21% vs 28%) were not statistically different during the follow-up between the 3-month 25-OH-D < 20 ng/mL and 3-month 25-OH-D > 20 ng/mL groups. There was a correlation between the 25-OH-D levels and PTH concentration at 3 months (r = -.2491, P = .01), but no correlation between the 3-month 25-OH-D and the season of the year (F = 0.19, P = .90; F = 1.34, P = .27, respectively). Multivariate analyses revealed that age and mGFR at 3 months, were independent predictors of mGFR at 12 months.

CONCLUSION

Our data show that vitamin D deficiency can develop rapidly after transplantation; vitamin D levels at 3 months are not associated with lower mGFR or a higher rejection rate at 1 year in children as opposed to adult recipients.

To D or not to D: vitamin D in hematopoietic cell transplantation

Vitamin D plays an essential role in bone health, immune tolerance, and immune modulation. Autologous and allogeneic hematopoietic cell transplantation (HCT) recipients are at increased risk of vitamin D deficiency, which may increase risks of bone loss and fracture, graft-versus-host disease (GVHD), and relapse, and can delay hematologic and immune recovery following HCT. Growing evidence indicates that vitamin D may have a role as an immunomodulator, and supplementation during HCT may decrease the risk of GVHD, infection, relapse, and mortality. In this paper, we review the role of vitamin D and its association with HCT outcomes and discuss prevention and treatment of vitamin D deficiency after HCT in adult recipients. We review the role of monitoring of vitamin D levels pre- and post-HCT and its supplementation in appropriate patients. We also review the use of bone densitometry prior to HCT and in long-term follow-up and the treatment of osteoporosis in this high-risk population.

Vitamin D Receptor Activity, Vitamin D Status, and Development of De-novo Donor-specific Antibody after Renal Transplantation

Introduction:

Vitamin D has immunomodulatory properties and could have a role in allograft outcome.

Methods:

Fifty-two chronic kidney disease patients going for transplantation were studied for vitamin-D receptor (VDR) activity, 25(OH)D, estimated glomerular filtration rate (e-GFR), and de-novo donor-specific antibody (d-DSA).

Results:

Vitamin D deficiency was seen in 25% of recipients before transplant (26.09 ± 12.19 ng/ml), in 48.1% at 6 months posttransplant (23.36 ± 15.11 ng/ml). VDR activity before the transplant was 15.41 ± 31.41 ng/ml, which was similar to control group (13.24 ± 9.78 ng/ml), and after transplantation showed an increase at 3 months to 21.91 ± 38.80 ng/ml and at 6 months to 26.03 ± 53.90 ng/ml. d-DSA developed in 27.3% and 6.7% patients of vitamin D-deficient patients (levels <31 ng/ml) and non-deficient (levels ≥20 ng/ml) patients respectively (P < 0.042). Low VDR activity at 3 months posttransplant was associated with significantly higher d-DSA positivity (33.3%) as compared to the group with normal VDR activity where d-DSA developed only in 5.9% of patients (P < 0.009). Patients with vitamin D levels <20 ng/ml and the group with low VDR activity at 3 months had significantly less e-GFR at 1 year after transplant.

Conclusion:

d-DSA was associated with vitamin D deficiency and low VDR activity with decreased graft GFR at 12 months posttransplant.

The Current Status of Cytomegalovirus (CMV) Prevalence in the MENA Region: A Systematic Review

Human cytomegalovirus (CMV) is a highly prevalent herpesvirus worldwide. According to the Centers for Disease Control and Prevention (CDC) and the World Health Organization (WHO), CMV infects people of all ages, and by the age of five, approximately one-third of children in the United States are infected. Although the infection is generally asymptomatic, it can cause severe disease in immunocompromised patients, transplant and transfusion recipients, as well as newborn neonates. The objective of this study is to systematically review published literature on CMV in the MENA region to estimate its incidence in the region and describe its epidemiological and clinical significance. The literature was searched through four scientific databases: PubMed, Scopus, Science Direct, and Web of Science. A total of 72 studies from 11 countries satisfied the inclusion criteria, covering a period from 1988-2019. The CMV IgG seroprevalence ranged from 8.7%-99.2% (SD = 38.95%). CMV incidence in these countries ranged between 1.22% and 77% in transplant and transfusion recipients, with an increase in incidence with advanced age. However, the incidence rate was unclear for congenital CMV due to the variability of the reporting. This review highlights the need for more robust and well-designed studies to better estimate CMV incidence in the MENA region, standardize diagnostic criteria, and consider prophylactic and pre-emptive treatments to limit the morbidity and mortality of the disease.