Increased incidence of chronic GvHD and CMV disease in patients with vitamin D deficiency before allogeneic stem cell transplantation

The Role of Vitamin D in Hematopoietic Stem Cell Transplantation: Implications for Graft-versus-Host Disease-A Narrative Review

INTRODUCTION/AIM

Vitamin D plays a crucial role in immune modulation, which may influence the development of graft-versus-host disease (GvHD) in patients undergoing hematopoietic stem cell transplantation (HSCT). This study aims to evaluate the impact of vitamin D levels and supplementation on the incidence of GvHD in HSCT patients.

METHODS

A narrative review was conducted across PubMed/Medline, Cochrane Library, CINAHL, and Embase databases.

RESULTS

The reviewed studies indicated widespread vitamin D deficiency among HSCT patients, with baseline levels ranging from 12.8 to 29.2 ng/mL. Supplementation protocols varied significantly, with dosages ranging from 1000 IU/day to 60,000 IU/week. Post-supplementation levels improved in some studies. Studies exploring the relationship between vitamin D and GvHD showed mixed results. Lower baseline vitamin D levels were associated with an increased risk of acute GvHD in some studies, while others found no significant correlation. However, a significant association between low levels of vitamin D and the incidence of chronic GvHD was observed.

CONCLUSION

Vitamin D deficiency is prevalent in HSCT patients and may influence the risk of developing chronic GvHD. Future research should focus on larger and more rigorous studies to determine the optimal role of vitamin D as an adjuvant therapy in the context of HSCT.

A Review of the Evidence for Tryptophan and the Kynurenine Pathway as a Regulator of Stem Cell Niches in Health and Disease

Stem cells are ubiquitously found in various tissues and organs in the body, and underpin the body's ability to repair itself following injury or disease initiation, though repair can sometimes be compromised. Understanding how stem cells are produced, and functional signaling systems between different niches is critical to understanding the potential use of stem cells in regenerative medicine. In this context, this review considers kynurenine pathway (KP) metabolism in multipotent adult progenitor cells, embryonic, haematopoietic, neural, cancer, cardiac and induced pluripotent stem cells, endothelial progenitor cells, and mesenchymal stromal cells. The KP is the major enzymatic pathway for sequentially catabolising the essential amino acid tryptophan (TRP), resulting in key metabolites including kynurenine, kynurenic acid, and quinolinic acid (QUIN). QUIN metabolism transitions into the adjoining de novo pathway for nicotinamide adenine dinucleotide (NAD) production, a critical cofactor in many fundamental cellular biochemical pathways. How stem cells uptake and utilise TRP varies between different species and stem cell types, because of their expression of transporters and responses to inflammatory cytokines. Several KP metabolites are physiologically active, with either beneficial or detrimental outcomes, and evidence of this is presented relating to several stem cell types, which is important as they may exert a significant impact on surrounding differentiated cells, particularly if they metabolise or secrete metabolites differently. Interferon-gamma (IFN-γ) in mesenchymal stromal cells, for instance, highly upregulates rate-limiting enzyme indoleamine-2,3-dioxygenase (IDO-1), initiating TRP depletion and production of metabolites including kynurenine/kynurenic acid, known agonists of the Aryl hydrocarbon receptor (AhR) transcription factor. AhR transcriptionally regulates an immunosuppressive phenotype, making them attractive for regenerative therapy. We also draw attention to important gaps in knowledge for future studies, which will underpin future application for stem cell-based cellular therapies or optimising drugs which can modulate the KP in innate stem cell populations, for disease treatment.

Variability of contribution of 1,25 (OH)2D3 (vitamin D) level to hematopoietic stem cell transplantation outcome

BACKGROUND

The impact of vitamin D status on the outcome of allogeneic hematopoietic stem cell transplantation (HSCT) has recently been the focus of interest with a lot of controversy. In this study we aimed to evaluate the impact of pre-transplant vit. D level on the outcome of HSCT.

METHODS

In this study, we evaluated the impact of vitamin D level on the risk of development of graft versus host disease (GVHD) and survival after HSCT. The study included 97 patients who received allogeneic HSCT from an identical sibling. Serum vitamin D level was measured before conditioning using ELIZA. Student t-test, Mann-Whitney U test, ANOVA F-test and Kruskal-Wallis H tests were used to determine significance of difference for quantitative data. Pearson correlation, Spearman correlation and Chi-square test were used to determine correlations and associations. Kaplan-Meier and Log rank (Mantel-Cox) tests were used for analysis of survival. P value ≤ 0.05 was considered significant.

RESULTS

Vitamin D level showed a range of 18.24-84.6 with a mean of 38.14 ± 9.73 and a median of 36.26 ng/ml. Two patients had vitamin D level <20 and 17 had a level <30 ng/ml. Acute GVHD occurred in 33 (34 %) and chronic GVHD in 29 (29.9 %) patients. Vitamin D level had no impact on frequency or severity of GVHD; either did it impact survival. This might be attributable to the relatively normal level in the majority of our patients on account of the sunny weather of Egypt. This might also be a potential explanation for the inconsistency of the different studies with variable levels of vitamin D.

CONCLUSIONS

The current study failed to demonstrate an impact of pre-transplant vitamin D level on the outcome of HSCT. This might be attributed to the low prevalence of vitamin D deficiency in our population on account of our almost always sunny weather. The marked variability in the level of vitamin D that is considered sufficient interferes with objective comparison between studies; a consensus on what is considered sufficient, insufficient, or deficient is essential.

Relevance of vitamin D in patients undergoing HLA matched allogeneic stem cell transplant for acute leukemia

BACKGROUND

In hematopoietic stem cell transplant (HSCT), vitamin D deficiency has been variably associated with increased complications, primarily graft versus host disease (GvHD), with a potential impact on survival. Results from various studies however, have not been consistent. This analysis was conducted to study the impact of peri-transplant vitamin D levels on transplant outcomes in patients with acute leukemia (AL) who underwent HLA matched (related/unrelated) HSCT.

METHODS

This was a single center retrospective study. Patients of AL including Acute Lymphoblastic Leukemia (ALL), Acute Myeloid Leukemia (AML) or Mixed Phenotypic Acute Leukemia (MPAL) who underwent fully matched or 9/10 transplants (related/unrelated) between 2008 and 2019 were included. Vitamin D deficiency was defined as serum 25-hydroxy vitamin D3 levels ≤20 ng/ml. Those with deficiency received replacement with oral vitamin D at a dose of 60,000 IU weekly for 8 weeks followed by maintenance with daily vitamin D (800 IU/day). Vitamin D levels were repeated at 4 months from start of replacement. For patients who received correction, repeat levels >20 ng/ml were considered replete. Based on vitamin D levels in the peri-transplant period (within 120 days of transplant), patients were categorised as either vitamin D replete (> 20 ng/ml) or deplete (≤ 20 ng/ml). Peri-transplant vitamin D status was correlated with transplant outcomes.

RESULTS

Of the 133 patients included, 31 were deplete (median vitamin D 15.0 ng/ml) and 102 were replete (median vitamin D 34 ng/ml) at time of transplant. Both groups were matched for age, diagnosis, EBMT score and disease risk index (DRI). There were no differences in time to neutrophil or platelet engraftment, CMV reactivation, acute GvHD (aGvHD) or chronic GvHD (cGvHD) between the two groups. Relapse rate, Progression Free Survival (PFS) and Overall Survival (OS) were also comparable between the 2 groups.

CONCLUSION

The incidence of vitamin D deficiency was high in our patient cohort. Patients who were vitamin D deficient at the time of transplant did not have inferior outcomes, suggesting a limited role of vitamin D in influencing transplant outcomes.

Loading dose vitamin D3 improves vitamin D insufficiency in adults undergoing hematopoietic stem cell transplantation: A randomized controlled trial

Allogeneic hematopoietic stem cell transplant (aHSCT) patients are well known to be at high risk of vitamin D (vit D) deficiency. This study assessed whether a loading dose (100,000 IU) of vitamin D3 pre-aHSCT could effectively achieve and maintain sufficient post-transplant vit D levels (serum total 25 hydroxy vitamin D (25(OH)D) ≥ 75nmol/L). Dual-energy X-ray absorptiometry (DXA) was also conducted for bone health evaluation. 74 patients were enrolled and randomly assigned, in a 1:1 ratio, either to the high vit D group (single loading dose (100,000 IU) plus 2,000 IU vit D3 daily) or the control group (2,000 IU vit D3 daily). Vit D levels were measured at three time points (baseline, day 30 and day 100 post-aHSCT). At baseline, fewer than 50% patients had a sufficient 25(OH)D (control: 42.9%; high vit D: 43.6%). The proportion of patients with sufficient 25(OH)D (nmol/L) was increased at day 30 and day 100, with a trend of higher proportion in the high vit D group at day 30 (high vit D vs. control: 89.7% vs. 74.3%, p = 0.08). The increased 25(OH)D was significantly higher in the high vit D group at day 30 (high vit D vs. control: 29±25.2 vs. 14 ±21.9, p = 0.01). Insufficient vit D level before transplant (baseline) was an independent risk factor for vit D insufficiency (serum 25(OH)D < 75nmol/L) post-aHSCT (OR = 4.16, p = 0.03). DXA suggested significant bone loss for total hip in both groups, and in the femoral neck for the control group only. In conclusion, single loading dose vitamin D3 significantly increased total 25(OH)D levels at day 30 post-transplant, and the intervention was especially beneficial for patients with baseline vit D insufficiency. We acknowledge that the primary outcome at day 100 post-aHSCT indicating superiority of loading dose versus daily dose supplementation was not met.

From support to therapy: rethinking the role of nutrition in acute graft-versus-host disease

Allogeneic Hematopoietic stem cell transplantation (HSCT) offers a potential cure for patients with hematologic malignancies. Unfortunately, graft-versus-host disease (GVHD) remains a major obstacle to the greater success of this treatment. Despite intensive research efforts over the past several decades, GVHD is still a major cause of morbidity and mortality in patients receiving allogeneic HSCT. The genetic disparity between donor and recipient is the primary factor that dictates the extent of alloimmune response and the severity of acute GVHD (aGVHD). However, some nongenetic factors are also actively involved in GVHD pathogenesis. Thus, identifying host factors that can be readily modified to reduce GVHD risk is of important clinical significance. We are particularly interested in the potential role of nutrition, as a nongenetic factor, in the etiology and management of aGVHD. In this article, we summarize recent findings regarding how different routes of nutritional support and various dietary factors affect aGVHD. Since diet is one of the most important factors that shape gut microbiota, we also provide evidence for a potential link between certain nutrients and gut microbiota in recipients of allogeneic HSCT. We propose a shifting role of nutrition from support to therapy in GVHD by targeting gut microbiota.

Effect of Vitamin D on Graft-versus-Host Disease

The different cell subsets of the immune system express the vitamin D receptor (VDR). Through the VDR, vitamin D exerts different functions that influence immune responses, as previously shown in different preclinical models. Based on this background, retrospective studies explored the impacts of vitamin D levels on the outcomes of patients undergoing allogeneic hematopoietic stem-cell transplantation, showing that vitamin D deficiency is related to an increased risk of complications, especially graft-versus-host disease. These results were confirmed in a prospective cohort trial, although further studies are required to confirm this data. In addition, the role of vitamin D on the treatment of hematologic malignancies was also explored. Considering this dual effect on both the immune systems and tumor cells of patients with hematologic malignancies, vitamin D might be useful in this setting to decrease both graft-versus-host disease and relapse rates.

Anti-Thymocyte Globulin Treatment Augments 1,25-Dihydroxyvitamin D3 Serum Levels in Patients Undergoing Hematopoietic Stem Cell Transplantation

Application of anti-thymocyte globulin (ATG) is a widely used strategy for the prevention of graft-versus-host disease (GvHD). As vitamin D3 serum levels are also discussed to affect hematopoietic stem cell transplantation (HSCT) outcome and GvHD development, we analysed a possible interplay between ATG treatment and serum levels of 25-hydroxyvitamin D3 and 1,25-dihydroxyvitamin D3 in 4 HSCT cohorts with different vitamin D3 supplementation. ATG is significantly associated with higher serum level of 1,25-dihydroxyvitamin D3 around HSCT (day -2 to 7, peri-transplant), however only in patients with adequate levels of its precursor 25-hydroxyvitamin D3. ATG exposure had no impact on overall survival in patients supplemented with high dose vitamin D3, but was associated with higher risk of one-year treatment-related mortality (log rank test p=0.041) in patients with no/low vitamin D3 supplementation. However, the difference failed to reach significance applying a Cox-model regression without and with adjustment for baseline risk factors (unadjusted P=0,058, adjusted p=0,139). To shed some light on underlying mechanisms, we investigated the impact of ATG on 1,25-Dihydroxyvitamin D3 production by human dendritic cells (DCs) in vitro. ATG increased gene expression of CYP27B1, the enzyme responsible for the conversion of 25-hydroxyvitamin D3 into 1,25-dihydroxyvitamin D3, which was accompanied by higher 1,25-dihydroxyvitamin D3 levels in ATG-treated DC culture supernatants. Our data demonstrate a cooperative effect of 25-hydroxyvitamin D3 and ATG in the regulation of 1,25-dihydroxyvitamin D3 production. This finding may be of importance in the context of HSCT, where early high levels of 1,25-dihydroxyvitamin D3 levels have been shown to be predictive for lower transplant related mortality and suggest that vitamin D3 supplementation may especially be important in patients receiving ATG for GvHD prophylaxis.

Impact of vitamin D level at diagnosis and transplantation on the prognosis of hematological malignancy: a meta-analysis

Vitamin D deficiency impairs prognosis in many types of cancer; however, its significance in each subtype of hematological malignancies is unclear. In addition, data on the association between pretransplant vitamin D levels and outcomes of hematopoietic stem cell transplantation (HSCT) are inconsistent. This systematic review and meta-analysis aimed to elucidate the impact of vitamin D levels at diagnosis or pre-HSCT on the prognosis of hematological malignancies. Thirty articles and abstracts were extracted from PubMed, Embase, and Cochrane Library databases and conference proceedings. Fixed and random effect models were used to analyze primary outcomes: overall survival (OS) and progression-free survival (PFS). Lower vitamin D level was significantly associated with poorer OS and PFS in myeloid malignancies (hazard ratio [HR], 1.39; 95% confidence interval [CI], 1.06-1.82 and HR, 2.03; 95% CI, 1.23-3.32, respectively) and lymphoid malignancies (HR, 2.07; 95% CI, 1.79-2.40 and HR, 1.91; 95% CI, 1.61-2.25, respectively), as well as outcomes for several lymphoma subtypes individually. Furthermore, a lower pretransplant vitamin D level was associated with poorer OS in autologous and allogeneic HSCT (HR, 1.65; 95% CI, 1.04-2.61 and HR, 1.50; 95% CI, 1.03-2.18, respectively). Despite the relatively small number of studies evaluated, these data suggest the importance of vitamin D status in outcomes of hematological malignancies (PROSPERO registration number: CRD42020205821).

Ultra-High Dose Vitamin D in Pediatric Hematopoietic Stem Cell Transplantation: A Nonrandomized Controlled Trial

Vitamin D is essential for bone health and has immunomodulatory properties. Most pediatric patients are vitamin D insufficient (<30 ng/mL) before hematopoietic stem cell transplantation (HSCT). Standard supplementation strategies fail to achieve vitamin D sufficiency in the acute post-transplantation period, and there are scarce data to support optimal vitamin D supplementation in this patient population. This study aimed to evaluate whether a single, oral, weight-based ultra-high dose of vitamin D (Stoss dosing) was more effective than standard supplementation to achieve pre-HSCT vitamin D sufficiency and reduce the incidence of HSCT-related complications (acute graft-versus-host disease, veno-occlusive disease, and/or transplant-associated thrombotic microangiopathy) that are associated with immune-mediated endothelial damage. Secondary endpoints examined the immunomodulatory properties of vitamin D. We conducted a nonrandomized controlled clinical trial of Stoss-dosed vitamin D in pediatric patients receiving HSCT. The study prospectively enrolled 33 patients, 29 of whom successfully received Stoss-dosed vitamin D and were compared to 136 patients in a historical control. Patient characteristics were compared using Fisher's exact test or t-test. The one-sided Fisher's exact test was used for cohort comparison of the primary endpoints. Logistic regression was used to examine the association between patient-specific factors and total 25-hydroxy vitamin D (25-OHD) levels and the compiled HSCT complications. In the Stoss cohort, 97% (n = 28/29) of patients achieved pre-HSCT vitamin D sufficiency compared to 67% (n = 10/15) of patients in the historical control who were on standard supplementation at the time the total 25-OHD level was assessed (P = .013). The mean total 25-OHD level in the Stoss cohort was significantly higher than patients in the historical control who received standard supplementation (72.2 ng/mL versus 35.8 ng/mL, P < .001). Nine patients in the Stoss cohort maintained vitamin D sufficiency throughout the first 100 days after HSCT, and the remaining 19 patients maintained sufficiency for a median of 63 days (range 6-105 days) from the Stoss dose. Patients receiving Stoss-dosed vitamin D developed a lower combined incidence of HSCT-related complications than the historical control (25% [n = 7/28] versus 42% [n = 57/136], P = .055). After Stoss dosing, immunophenotyping studies found a significant decrease in subsets of CD8+ T cells and mononuclear cells (P = .040 and.013, respectively), and, in a subset of cells, larger decreases in phosphoprotein expression were seen with greater increases in total 25-OHD levels. Inflammatory cytokines did not change significantly after Stoss dosing. Stoss dosing is therefore a safe and effective approach to maintain vitamin D sufficiency in the immediate post-HSCT period and may be associated with decreased HSCT-related complications. Randomized studies are warranted to further investigate the efficacy of Stoss-dosed vitamin D to improve bone health and reduce complications in pediatric patients receiving HSCT.

Stoss therapy is safe for treatment of vitamin D deficiency in pediatric patients undergoing HSCT

Vitamin D deficiency remains common among pediatric patients undergoing hematopoietic stem cell transplant (HSCT) despite both aggressive and standard of care strategies. This study examined the safety and efficacy of single high-dose oral vitamin D therapy (Stoss therapy) for treatment of vitamin D deficiency in HSCT recipients. Patients ages 1-21 years presenting for HSCT were randomized to receive either Stoss regimen plus weekly/daily supplementation or standard of care, per US Endocrine Society guidelines. Among the total 48 subjects, 22 (46%) were randomized to Stoss and 26 (54%) to control arms. Baseline 25-hydroxyvitamin D (25-OHD) levels were insufficient/deficient in total of 34 (71%) patients, without difference between treatment groups. The Stoss regimen was well tolerated and no toxicity was observed. At Day +30, mean 25-OHD levels were significantly higher (P = 0.04) with Stoss (42.3 ± 12 μg/l) compared to controls (35.6 ± 14.3 μg/l), and a higher proportion of Stoss patients had adequate vitamin D levels than controls (85% vs 65%). Stoss therapy is a safe and efficacious treatment option for vitamin D deficiency in children undergoing HSCT and may achieve sufficient levels more rapidly than standard of care. This trial was registered at www.clinicaltrials.gov as NCT03176849.

Vitamin D Deficiency, Osteoporosis and Effect on Autoimmune Diseases and Hematopoiesis: A Review

Vitamin D (VD) is essential for bone homeostasis, but it is also involved in pleiotropic effects on various organs and tissues. In adults, VD deficiency can cause or exacerbate osteoporosis and induce osteomalacia. However, every tissue and cell in the body has a VD receptor, including the brain, heart, stomach, pancreas, skin, gonads, and immune cells, and a deficiency may modify the function of these organs. Thus, the wide-ranging actions of VD help to explain why a reduction in VD amount has been correlated with numerous chronic diseases. In fact, VD deficiency increases the risk of osteoporosis and several other diseases and complications characterized by impaired bone metabolisms, such as autoimmune diseases, inflammatory bowel diseases, allergy, endocrinological diseases, hematological malignancies, and bone marrow transplantation. This review aims to investigate the link between VD deficiency, osteoporosis, and its concomitant diseases. Further epidemiological and mechanistic studies are necessary in order to ascertain the real role of hypovitaminosis in causing the reported diseases; however, adequate vitamin supplementation and restoration of metabolic normality could be useful for better management of these pathologies.

Pre-transplantation plasma vitamin D levels and acute graft-versus-host disease after myeloablative hematopoietic cell transplantation in adults

BACKGROUND

The association between vitamin D and acute graft-versus-host disease (GvHD) remains controversial, especially for patients receiving myeloablative conditioning.

METHODS

We measured pre-transplantation plasma vitamin D (25-hydroxyvitamin D₃ + D₂) levels by competitive electrochemiluminescence in plasma samples from 116 adult patients who underwent a myeloablative allogeneic transplantation at Rigshospitalet, Copenhagen between July 2015 and August 2018.

RESULTS

The median (Q1, Q3) pre-transplantation plasma vitamin D level was 64 (47, 85) nmol/L (normal range: 50-160 nmol/L). Vitamin D insufficiency (<50 nmol/L) and moderate deficiency (<25 nmol/L) were observed in 29% and 8% of patients, respectively. No patients had a severe deficiency (<12 nmol/L). Pre-transplantation vitamin D levels were slightly higher in patients who later developed grade II-IV acute GvHD (mean difference: 8.1 nmol/L), but the 95% confidence interval [CI] encompassed clinically insignificant differences (CI: -2.2, 19.2 nmol/L). From multivariable logistic regression, we found that a patient with a pre-transplantation vitamin D level of 85 nmol/L (Q3) had 1.5 times higher odds of grade II-IV acute GvHD than a patient with a level of 47 nmol/L (Q1; CI of odds ratio: 0.84, 2.7; adjusted for patient age, donor type, use of anti-thymocyte globulin, and use of 12 Gy total-body irradiation). Patients with pre-transplantation vitamin D insufficiency (N = 34) had a cumulative incidence of grade II-IV acute GvHD similar to that of patients with vitamin D sufficiency (26% [CI: 11%, 42%] versus 35% [CI: 25%, 46%], respectively).

CONCLUSIONS

Our data did not support an association between pre-transplantation vitamin D levels or vitamin D insufficiency and acute GvHD in adult patients receiving myeloablative conditioning.

Cytomegalovirus Infection Downregulates Vitamin D Receptor in Patients Undergoing Hematopoietic Stem Cell Transplantation

BACKGROUND

Allogeneic hematopoietic stem cell transplantation (HSCT) is a potentially curative option for patients with hematologic diseases but is associated with high mortality and morbidity. Cytomegalovirus (CMV) infection is common in HSCT patients and modulates vitamin D metabolism in vitro. We aimed at validating CMV-associated vitamin D metabolism in vivo in HSCT.

METHODS

Patients treated for significant CMV viremia after HSCT were evaluated for CMV load before, during, and after antiviral treatment. RNA was isolated from whole-blood samples to test for regulation of key components of the vitamin D receptor (VDR) pathway during different phases of CMV viremia.

RESULTS

CMV viremia developed a mean time of 102 (±34) d post-HSCT. Maximum levels of CMV-DNA reached a mean of 5668 (±7257) copies/mL. VDR expression was downregulated to a mean of 64.3% (±42.5%) relative to the VDR expression pre-CMV viremia (P = 0.035) and lagged in recovery following antiviral treatment. Toll-like receptor (TLR) 2 mRNA was upregulated to 225.4% during CMV viremia relative to the expression pre-CMV viremia (P = 0.012) but not TLR6/7/8 and the TLR-adaptor protein MyD88. Levels of 25-OH vitamin D were reduced in all viremic patients (48.0 ± 4.8 versus 25.1 ± 3.7 ng/mL) and were even lower after periods of CMV viremia compared with the control group (48.3 ± 3.5 versus 17.8 ± 1.8 ng/mL; P = 0.008).

CONCLUSIONS

CMV viremia is associated with significant dysregulation of vitamin D metabolism in HSCT patients.

Vitamin D has no impact on outcomes after HSCT in children-A retrospective study

Vitamin D not only plays an important role in bone metabolism but is also involved in multiple immune-mediated processes in the body which may be adversely affected in those with low levels. Most pediatric studies evaluating the association of vitamin D in patients undergoing allogeneic HSCT are single-center studies. We present the results of retrospective study at 5 centers across the United States in pediatric patients undergoing allogeneic HSCT. (VDD) and (VDI) were defined by vitamin D levels of <20 ng/ml and 21-30 ng/ml, respectively. The mean vitamin D levels pre-HSCT, day +30, and +100 were suggestive of VDI, but normalized thereafter. We compared the transplant characteristics and outcomes in 233 patients with VDD and VDI and those with normal levels and found no statistical difference in neutrophil or platelet engraftment, infections (viral, bacterial, or fungal) post-HSCT, length of hospital stay during HSCT, graft failure, acute or chronic GvHD, survival at day +100 and 1 year, or relapse of primary malignancy. We conclude that VDI or deficiency does not affect any of the common transplant variables after allogeneic HSCT in children. There is a need of a large multicenter prospective study to evaluate its role further.

1,25-dihydroxyvitamin-D3 but not the clinically applied marker 25-hydroxyvitamin-D3 predicts survival after stem cell transplantation

The serum level of 25-hydroxyvitamin-D3 is accepted as marker for a person’s vitamin D status but its role for the outcome of allogeneic hematopoietic stem cell transplantation (HSCT) is controversially discussed. The impact of 1,25-dihydroxyvitamin-D3 on HSCT outcome, however, has never been studied. In a discovery cohort of 143 HSCT patients we repeatedly (day −16 to 100) measured 1,25-dihydroxyvitamin-D3 and in comparison the well-established marker for serum vitamin D status 25-hydroxyvitamin-D3. Only lower 1,25-dihydroxyvitamin-D3 levels around HSCT (day −2 to 7, peritransplant) were significantly associated with higher 1-year treatment-related mortality (TRM) risk (Mann–Whitney U test, P = 0.001). This was confirmed by Cox-model regression without and with adjustment for baseline risk factors and severe acute Graft-versus-Host disease (aGvHD; unadjusted P = 0.001, adjusted P = 0.005). The optimal threshold for 1,25-dihydroxyvitamin-D3 to identify patients at high risk was 139.5 pM. Also in three replication cohorts consisting of altogether 365 patients 1,25-dihydroxyvitamin-D3 levels below 139.5 pM had a 3.3-fold increased risk of TRM independent of severe aGvHD compared to patients above 139.5 pM (Cox-model unadjusted P < 0.0005, adjusted P = 0.001). Our data highlight peritransplant 1,25-dihydroxyvitamin-D3 levels but not the commonly monitored 25-hydroxyvitamin-D3 levels as potent predictor of 1-year TRM and suggest to monitor both vitamin D metabolites in HSCT patients.

Vitamin D deficiency is not associated with graft versus host disease after hematopoietic stem cell transplantation: A meta-analysis

OBJECTIVE

Vitamin D status plays an important role in immunoregulation, and a deficiency is believed to be related to Graft Versus Host Disease (GVHD) in patients after hematopoietic stem cell transplantation (HSCT). We aim to study the association between vitamin D deficiency and GVHD after HSCT.

METHODS

A literature search was conducted utilizing MEDLINE, EMBASE, and The Cochrane Library Database from inception to July 2019. Eligible studies were required to¹ be clinical trials or observational studies (cohort, case-control, or cross-sectional studies);² provide data to calculate the odds ratios (OR) of GVHD in HSCT patients with vitamin D deficiency. Two reviewers independently extracted the data and assessed the risk of bias. Pooled odds ratios (OR) with 95% confidence interval (CI) were estimated using random-effects meta-analysis through the Comprehensive Meta-Analysis 3.3 software.

RESULTS

In total, 8 observational studies consisting of 1335 HSCT patients were enrolled in this systematic review. Overall, there was no significant association between vitamin D deficiency and acute GVHD (OR = 1.06, 95% CI 0.74-1.53, P > 0.05). There was no significant association between vitamin D deficiency and chronic GVHD (OR = 1.75, 95% CI 0.72-4.26, P > 0.05). Funnel plots and Egger regression asymmetry test were performed and showed no publication bias.

CONCLUSION

There is not a statistically significant association between vitamin D deficiency and neither acute nor chronic GVHD.

Vitamin D intake is associated with decreased risk of immune checkpoint inhibitor-induced colitis

BACKGROUND

There is a lack of predictive markers informing on the risk of colitis in patients treated with immune checkpoint inhibitors (ICIs). The aim of this study was to identify potential factors associated with development of ICI colitis.

METHODS

We performed a retrospective analysis of melanoma patients at Dana-Farber Cancer Institute who received PD-1, CTLA-4, or combination ICIs between May 2011 to October 2017. Clinical and laboratory characteristics associated with pathologically confirmed ICI colitis were evaluated using multivariable logistic regression analyses. External confirmation was performed on an independent cohort from Massachusetts General Hospital.

RESULTS

The discovery cohort included 213 patients of whom 37 developed ICI colitis (17%). Vitamin D use was recorded in 66/213 patients (31%) before starting ICIs. In multivariable regression analysis, vitamin D use conferred significantly reduced odds of developing ICI colitis (OR 0.35, 95% CI 0.1-0.9). These results were also demonstrated in the confirmatory cohort (OR 0.46, 95% CI 0.2-0.9) of 169 patients of whom 49 developed ICI colitis (29%). Pre-treatment neutrophil-to-lymphocyte ratio (NLR) ≥5 predicted reduced odds of colitis (OR 0.34, 95% CI 0.1-0.9) only in the discovery cohort.

CONCLUSIONS

This is the first study to report that among patients treated with ICIs, vitamin D intake is associated with reduced risk for ICI colitis. This finding is consistent with prior reports of prophylactic use of vitamin D in ulcerative colitis and graft-versus-host-disease. This observation should be validated prospectively in future studies.

Insights Into the Role of Vitamin D as a Biomarker in Stem Cell Transplantation

Vitamin D was discovered 100 years ago and since then multiple studies have consistently proved its effect on bone health and mineral metabolism. Further research has also explored its so-called "non-classical" biological effects, encompassing immune regulation and control of cell proliferation and differentiation. Vitamin D downregulates pro-inflammatory immune cells and subsequently their cytokine production, while enhancing the anti-inflammatory subsets, thus mediating inflammation and fostering a more tolerogenic environment. Its biological action is exerted through the vitamin D receptor, a nuclear receptor that mediates gene transcription and is expressed in most cells from the innate and adaptive immunity. Owing to its immune-modulatory properties, its role in cancer pathophysiology, hematology disorders and stem cell transplantation has also been investigated. Vitamin D deficiency causes immune imbalance and cytokine dysregulation, contributing to some autoimmune diseases. In the hematopoietic stem cell transplant setting this could lead to complications such as acute and chronic graft-versus-host disease, ultimately impacting transplant outcomes. Other factors have also been linked to this, including specific polymorphisms of the vitamin D receptor in both stem cell donors and recipients. Nevertheless, studies thus far have shown conflicting results and the use of vitamin D or its receptor as biomarkers has not been validated yet, therefore there are no evidence-based consensus guidelines to guide clinicians in their day-to-day practice. To gain more insight in this topic, we have reviewed the existent literature and gathered the current evidence. This is an overview of the role of serum vitamin D and its receptor as biomarkers for clinical outcomes in patients undergoing hematopoietic stem cell transplantation. Further prospective studies with larger cohorts are warranted to validate the viability of using serum vitamin D, and its receptor, as biomarkers in potential stem cell donors and patients, to identify those at risk of post-transplant complications and enable early therapeutic interventions.

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.

Controversial Effects of Vitamin D and Related Genes on Viral Infections, Pathogenesis, and Treatment Outcomes

Vitamin D (VD) plays an essential role in mineral homeostasis and bone remodeling. A number of different VD-related genes (VDRG) are required for the metabolic activation of VD and the subsequent induction of its target genes. They include a set of genes that encode for VD-binding protein, metabolic enzymes, and the VD receptor. In addition to its well-characterized skeletal function, the immunoregulatory activities of VD and the related polymorphisms of VDRG have been reported and linked to its therapeutic and preventive actions for the control of several viral diseases. However, in regards to their roles in the progression of viral diseases, inconsistent and, in some cases, contradictory results also exist. To resolve this discrepancy, I conducted an extensive literature search by using relevant keywords on the PubMed website. Based on the volume of hit papers related to a certain viral infection, I summarized and compared the effects of VD and VDRG polymorphism on the infection, pathogenesis, and treatment outcomes of clinically important viral diseases. They include viral hepatitis, respiratory viral infections, acquired immunodeficiency syndrome (AIDS), and other viral diseases, which are caused by herpesviruses, dengue virus, rotavirus, and human papillomavirus. This review will provide the most current information on the nutritional and clinical utilization of VD and VDRG in the management of the key viral diseases. This information should be valuable not only to nutritionists but also to clinicians who wish to provide evidence-based recommendations on the use of VD to virally infected patients.

Brazilian Nutritional Consensus in Hematopoietic Stem Cell Transplantation: Graft- versus -host disease

The Brazilian Consensus on Nutrition in Hematopoietic Stem Cell Transplantation: Graft- versus -host disease was approved by Sociedade Brasileira de Transplante de Medula Óssea , with the participation of 26 Brazilian hematopoietic stem cell transplantation centers. It describes the main nutritional protocols in cases of Graft- versus -host disease, the main complication of hematopoietic stem cell transplantation.

Brazilian Nutritional Consensus in Hematopoietic Stem Cell Transplantation: Adults

The nutritional status of patients submitted to hematopoietic stem cell transplant is considered an independent risk factor, which may influence on quality of life and tolerance to the proposed treatment. The impairment of nutritional status during hematopoietic stem cell transplant occurs mainly due to the adverse effects resulting from conditioning to which the patient is subjected. Therefore, adequate nutritional evaluation and follow-up during hematopoietic stem cell transplant are essential. To emphasize the importance of nutritional status and body composition during treatment, as well as the main characteristics related to the nutritional assessment of the patient, the Brazilian Consensus on Nutrition in Hematopoietic Stem Cell Transplant: Adults was prepared, aiming to standardize and update Nutritional Therapy in this area. Dietitians, nutrition physicians and hematologists from 15 Brazilian centers thar are references in hematopoietic stem cell transplant took part.

Oral calcitriol in hematopoietic recovery and survival after autologous stem cell transplantation: a randomized clinical trial

BACKGROUND

Calcitriol, the active metabolite of vitamin D, is an essential regulator in the hematopoiesis and immunity. However, knowledge revealing its influence on the immune and hematologic reconstitution after hematopoietic stem cell transplantation (HSCT) in clinical trials is very limited.

OBJECTIVES

The effects of calcitriol on short-term and long-term hematopoietic recovery, relapse-free survival (RFS) and overall survival (OS) in multiple myeloma, Hodgkin's and non-Hodgkin's lymphoma following autologous peripheral blood HSCT were assessed.

METHODS

Eighty patients (age: 18-68 years) in complete remission were allocated 1:1 to two groups by balanced block randomization. Calcitriol 0.25 μg or placebo capsule was administered three times daily from transplantation to day 30. Absolute neutrophil count (ANC), absolute lymphocyte count (ALC), and platelet count (PC) were determined daily from transplantation to day 30. White blood cell count (WBC), PC, and hemoglobin concentration (HC) of days 180 and 365 were extracted from clinic files. A thorough examination for oral mucositis (OM) was completed daily during hospital stay. Adverse drug reactions (ADRs) as well as two-year RFS and OS were evaluated.

RESULTS

Median time to ANC engraftment (≥0.5 × 103/μl: 10.0 vs. 11.0 days; P = 0.98) and PC engraftment (≥20.0 × 103/μl: both 14.0 days; P = 0.58) was similar between groups. However, the median time to ALC recovery was significantly shorter in the calcitriol group (≥0.5 × 103/μl: 13.0 vs. 20.0 days; P < 0.001). Moreover, ALC recovery rates on day 15 (≥0.5 × 103/μl: 82.1% vs. 42.5%; P < 0.001) and on day 30 (≥1.0 × 103/μl: 91.7% vs. 57.5%; P = 0.001) was significantly higher with calcitriol. WBC, PC, and HC on days 180 and 365 were not significantly different between groups. None of the OM indices were modulated by calcitriol. All the ADRs were non-serious and mild, possibly or unlikely related to the intervention. In a median of 29 months follow-up, RFS was significantly better in the calcitriol group (77.0%, SE = 7.0% vs. 59.0%, SE = 8.0%; P = 0.03), albeit the OS was not affected (87.0%, SE = 5.0% vs. 92.0%, SE = 4.0%; P = 0.72).

CONCLUSION

Calcitriol could improve ALC recovery and RFS as a safe option post-HSCT. Graphical abstract Oral calcitriol 0.25 µg three times daily from transplantation to day 30 improved lymphocytes recovery and two-year relapse-free survival as a safe option in 80 patients of autologous hematopoietic stem cell transplantation in comparison with placebo.

Bone and hormonal status 10 years post-allogeneic bone marrow transplantation

Bone loss and endocrine dysfunction are potential late complications of allogeneic stem cell transplant (allo-SCT); however, scant information concerning the long-term effects in SCT adult patients is available. In the present study, we evaluated bone status, expressed as bone mineral density (BMD), and endocrine functions including PTH, TSH, free T4, testosterone, SHBG, FSH, LH, and IGF-1, in 20 adult leukemia patients >10 years after allo-SCT. A low BMD (Z score <-2.0) was observed in two patients; two patients had osteoporotic fractures, and two had a unilateral avascular necrosis of the femoral head. Elevated PTH was observed in 30% of patients, and 25-hydroxy vitamin D (25(OH)D) was low (<50 nmol/L) in 45% of the patients. The majority of the patients had thyroid tests within the reference range, while elevated FSH values were present in 8 of 12 males. We conclude that adult leukemia patients have relatively well-preserved BMD >10 years post-allo-SCT. Prophylactic treatment of osteoporosis should be individualized, but control of BMD is necessary for long-term follow-up. Control of PTH and vitamin D levels before and after allo-SCT is recommended, and vitamin D supplementation should be considered if indicated. Estrogen replacement therapy is a routine treatment in females, whereas gonadal function in males requires further investigation.

Managing Endocrine Disorders in Adults After Hematopoietic Stem Cell Transplantation

Hematopoietic stem cell transplantation (HSCT) has become a potentially curative therapy for an increasing number of malignant and non-malignant conditions. As survival rates continue to improve, the focus of patient care has shifted from managing not only immediate but also long-term complications. Endocrine disorders are among the most prevalent late effects following HSCT. Detecting and treating such conditions offer new challenges, as well as opportunities to reduce preventable morbidity and mortality associated with HSCT. Our objective is to summarize recent literature and describe practical approaches to screening for and managing endocrine-related late effects. We focus on dyslipidemia, diabetes, thyroid disorders, osteoporosis, and hypogonadism. Mechanisms, monitoring, and management recommendations for each disorder are outlined. Growing data on these disorders in the post-transplant setting highlight the need for future study and evidence-based guidelines.

Current Practice in Vitamin D Management in Allogeneic Hematopoietic Stem Cell Transplantation: A Survey by the Transplant Complications Working Party of the European Society for Blood and Marrow Transplantation

Beyond its impact on bone health, numerous studies have investigated the immune-regulatory properties of vitamin D and shown how its deficiency can affect outcomes in allogeneic hematopoietic stem cell transplantation (HSCT), particularly in acute or chronic graft-versus-host disease. This survey, carried out by the Transplant Complications Working Party of the European Society for Blood and Marrow Transplantation (EBMT), describes the current clinical practice discrepancies across the EBMT HSCT programs. We therefore recommend the development of evidence-based guidelines to standardize evaluation criteria and to harmonize the management of vitamin D deficiency in patients undergoing allogeneic HSCT.

Vitamin D Modifies the Incidence of Graft-versus-Host Disease after Allogeneic Stem Cell Transplantation Depending on the Vitamin D Receptor (VDR) Polymorphisms

PURPOSE

The biologically active metabolite of vitamin D3, 1,25-dihydroxyvitamin D3 (vit D), has immunoregulatory properties via binding vitamin D receptor (VDR). In a prospective trial, we previously reported a reduction in the incidence of chronic GvHD (cGvHD) among patients who received vit D after allogeneic stem cell transplantation (allo-HSCT; Clinical Trials.gov: NCT02600988). Here we analyze the role of patients and donors' VDR SNPs on the immunomodulatory effect of vit D.

PATIENTS AND METHODS

Patients undergoing allo-HSCT were included in a prospective phase I/II clinical trial (Alovita) in three consecutive cohorts: control (without vit D), low-dose (1,000 IU/day), and high-dose (5,000 IU/day) groups. Vit D was given from day -5 until +100 after transplant. Genotyping of four SNPs of the VDR gene, FokI, BsmI, ApaI, and TaqI, were performed using TaqMan SNP genotyping assays.

RESULTS

We observed a decrease in the incidence of overall cGvHD at 1 year after allo-HSCT depending on the use or not of vit D among patients with FokI CT genotype (22.5% vs 80%, P = 0.0004) and among those patients without BsmI/ApaI/TaqI ATC haplotype (22.2% vs 68.8%, P = 0.0005). In a multivariate analysis, FokI CT genotype significantly influenced the risk of cGvHD in patients treated with vit D as compared with the control group (HR 0.143, P _interaction < 0.001).

CONCLUSIONS

Our results show that the immunomodulatory effect of vit D depends on the VDR SNPs, and patients carrying the FokI CT genotype display the highest benefit from receiving vit D after allo-HSCT.

The Role of Micronutrients in Graft-VS.-Host Disease: Immunomodulatory Effects of Vitamins A and D

Graft-vs.-host disease (GVHD) remains a major obstacle to the success of allogeneic hematopoietic stem cell transplantation (HSCT). GVHD occurs because donor T cells in the allograft recognize the genetically disparate host as foreign and attack the transplant recipient's tissues. While genetic incompatibility between donor and recipient is the primary determinant for the extent of alloimmune response, GVHD incidence and severity are also influenced by non-genetic factors. Recent advances in immunology establish that environmental factors, including dietary micronutrients, contribute significantly to modulating various immune responses and may influence the susceptibility to autoimmune and inflammatory diseases of experimental animals and humans. Emerging clinical and preclinical evidence indicates that certain micronutrients may participate in regulating GVHD risk after allogeneic HSCT. In this review, we summarize recent advances in our understanding with respect to the potential role of micronutrients in the pathogenesis of acute and chronic GVHD, focusing on vitamins A and D.

Vitamin D: Effect on Haematopoiesis and Immune System and Clinical Applications

Vitamin D is a steroid-like hormone which acts by binding to vitamin D receptor (VDR). It plays a main role in the calcium homeostasis and metabolism. In addition, vitamin D display other important effects called “non-classical actions.” Among them, vitamin D regulates immune cells function and hematopoietic cells differentiation and proliferation. Based on these effects, it is currently being evaluated for the treatment of hematologic malignancies. In addition, vitamin D levels have been correlated with patients’ outcome after allogeneic stem cell transplantation, where it might regulate immune response and, accordingly, might influence the risk of graft-versus-host disease. Here, we present recent advances regarding its clinical applications both in the treatment of hematologic malignancies and in the transplant setting.

Characterization of monocyte subtypes regarding their phenotype and development in the context of graft-versus-host disease

Graft-versus-host disease (GvHD) is a major cause of morbidity and mortality after allogeneic hematopoietic cell transplantation (HCT). In this study, monocyte subtypes were characterized regarding cytokine expression pattern and development in the context of GvHD. Using inflammatory S100 proteins for monocyte stimulation, it could be demonstrated that intermediate monocytes are the main producers of inflammatory cytokines such as IL-6 and TNFα known to be involved in the development of Th17 cells pointing towards an inflammatory phenotype of this monocyte subtype. Furthermore, novel aspects regarding monocyte subtype development were found. Our data reveal that prednisolone promotes the induction of intermediate monocytes from classical monocytes which correlates with HSP70 expression levels. However, 1α,25-Dihydroxyvitamin D3 treatment results in the abrogation of the prednisolone-mediated induction of this inflammatory monocyte subset and low HSP70 expression levels. Treatment of classical monocytes with pifithrin-μ, a specific HSP70 inhibitor, also leads to an inhibited induction of intermediate monocytes in the presence of prednisolone. These data point towards a predominant role of HSP70 in the development of intermediate monocytes. Thus, HSP70 might be a promising target for GvHD therapy, especially in combination with glucocorticoids, in order to decrease intermediate monocyte subset levels.

Single Ultra-High-Dose Cholecalciferol to Prevent Vitamin D Deficiency in Pediatric Hematopoietic Stem Cell Transplantation

Vitamin D deficiency is prevalent among childhood hematopoietic stem cell transplantation (HSCT) recipients and associated with inferior survival at 100 days after transplantation. Achieving and maintaining therapeutic vitamin D levels in HSCT recipients is extremely challenging in the first 3 to 6 months after transplantation due to poor compliance in the setting of mucositis and the concomitant use of critical transplantation drugs that interfere with vitamin D absorption. We sought to evaluate the safety and efficacy of a single, ultra-high-dose of vitamin D given before childhood HSCT to maintain levels in a therapeutic range during the peritransplantation period. Ten HSCT recipients with pretransplantation 25-OH vitamin D (25OHD) level <50 ng/mL and with no history of hypercalcemia, nephrolithiasis, or pathological fractures were enrolled on this pilot study. A single enteral vitamin D dose (maximum 600,000 IU) was administered to each patient based on weight and pretransplantation vitamin D level before the day of HSCT. Vitamin D levels between 30 and 150 ng/mL were considered therapeutic. All patients received close clinical observation and monitoring of 25OHD levels, calcium, phosphate, parathyroid hormone, urine calcium/creatinine ratio, and n-telopeptide for safety and efficacy assessment. The mean age of the study subjects was 5.8 ± 4.9 years, and the mean pretransplantation 25OHD level was 28.9 ± 13.1 ng/mL. All patients tolerated single, ultra-high-oral dose of vitamin D under direct medical supervision. No other oral vitamin D supplements were administered during the observation window of 8 weeks. Three of 10 patients received 400 IU/day of vitamin D in parenteral nutrition only for 5 days during the study window. A mean peak serum vitamin D level of 80.4 ± 28.6 ng/mL was reached at a median of 9 days after the vitamin D dose. All patients achieved a therapeutic vitamin D level of >30 ng/mL. Mean vitamin D levels were sustained at or above 30 ng/mL during the 8-week observation window. There were no electrolyte abnormalities attributed to the ultra-high-dose of vitamin D. Most patients had mildly elevated urine calcium/creatinine ratios during treatment, but none showed clinical or radiologic signs of nephrocalcinosis or nephrolithiasis. Our findings indicate that single ultra-high-oral dose vitamin D treatment given just before HSCT is safe and well tolerated in the immediate peritransplant period in children. Patients in our study were able to achieve and sustain therapeutic vitamin D levels throughout the critical period during which vitamin D insufficiency is associated with decreased overall survival. Larger prospective studies are needed to address the impact of single ultra-high-dose vitamin D treatment on HSCT outcomes.

Vitamin D deficiency in children with recurrent respiratory infections, with or without immunoglobulin deficiency

PURPOSE

The objective of this study was to evaluate thevitamin D concentration in patients with recurrent respiratory infections with or without immunoglobulin G, A or M (IgG, IgA, IgM) deficiency, and to find a correlation between the vitamin D concentration and the response to hepatitis B vaccination.

MATERIALS AND METHOD

The study involved 730 patients with recurrent respiratory infections. The concentration of 25-hydroxyvitamin D (25(OH)D), immunoglobulins G, A and M, anti-HBs was determined.

RESULTS

The tests showed that 11% of patients presented IgG levels below the age related reference values. Children with reduced IgG concentration were also found to have significantly lower vitamin D concentrations in comparison to children with normal IgG. Vitamin D deficiency was observed in schoolchildren between 7 and 18 years of age. No correlation was found between 25(OH)D concentration and Hbs antibody levels.

CONCLUSIONS

An investigation of a large group of patients who have recurrent infection found patients with IgG deficiency to whom special proceeding have to be performed: 1. Significantly lower vitamin D concentration observed in the group of children with IgG deficiency implicated in long-lasting monitoring of vitamin D level require adding to the practice guidelines for Central Europe 2013. 2. Intervention treatment with suitable doses of vitamin D to clarified metabolism of vitamin D has to be plan for children with IgG deficiency and significant lower vitamin D concentration.

Vitamin D deficiency and outcomes in pediatric hematopoietic stem cell transplantation

BACKGROUND

Pediatric patients undergoing hematopoietic stem cell transplantation (HSCT) are frequently diagnosed with vitamin D deficiency, which may impact outcomes.

OBJECTIVES

To estimate the prevalence of vitamin D deficiency and examine its association with short-term survival in pediatric HSCT patients.

METHODS

Patients undergoing HSCT at Phoenix Children's Hospital were retrospectively identified. Routine serum 25-hydroxyvitamin D measurements were described prior to transplant and at 100 days and 1-year post-HSCT. Associations of pre-HSCT vitamin D groups (i.e., normal ≥30 ng/ml, insufficient 20-29 ng/ml, and deficient <30 ng/ml) with demographics, clinical factors, and outcomes were examined using nonparametric tests and Cox proportional hazards analyses.

RESULTS

Among 72 study subjects, the median vitamin D pre-HSCT was 26 ng/ml (range: 19-34 ng/ml). Levels were insufficient and deficient in 25 (35%) and 20 (28%) patients, respectively, with only two (3%) patients on supplemental therapy pre-HSCT. Despite supplemental therapy provided to 46 (74%) subjects, insufficient/deficient rates did not significantly change between pre-HSCT and 100 days post-HSCT, but mean vitamin D levels significantly increased by 1-year post-HSCT (P = 0.01).Vitamin D pre-HSCT was not associated with the development of acute or chronic graft-versus-host disease (GVHD) or delayed engraftment. Overall 1-year survival was significantly lower for patients with deficient (65%) compared to normal (93%) pre-HSCT vitamin D (P = 0.001).

CONCLUSION

Suboptimal vitamin D levels are common in pediatric patients scheduled to receive HSCT and are associated with lower overall 1-year survival. Further study is warranted to delineate the mechanisms underlying the role of vitamin D in successful HSCT.

Developmental Vitamin D Availability Impacts Hematopoietic Stem Cell Production

Vitamin D insufficiency is a worldwide epidemic affecting billions of individuals, including pregnant women and children. Despite its high incidence, the impact of active vitamin D3 (1,25(OH)D3) on embryonic development beyond osteo-regulation remains largely undefined. Here, we demonstrate that 1,25(OH)D3 availability modulates zebrafish hematopoietic stem and progenitor cell (HSPC) production. Loss of Cyp27b1-mediated biosynthesis or vitamin D receptor (VDR) function by gene knockdown resulted in significantly reduced runx1 expression and Flk1+cMyb+ HSPC numbers. Selective modulation in vivo and in vitro in zebrafish indicated that vitamin D3 acts directly on HSPCs, independent of calcium regulation, to increase proliferation. Notably, ex vivo treatment of human HSPCs with 1,25(OH)D3 also enhanced hematopoietic colony numbers, illustrating conservation across species. Finally, gene expression and epistasis analysis indicated that CXCL8 (IL-8) was a functional target of vitamin D3-mediated HSPC regulation. Together, these findings highlight the relevance of developmental 1,25(OH)D3 availability for definitive hematopoiesis and suggest potential therapeutic utility in HSPC expansion.

Increase of Intermediate Monocytes in Graft-versus-Host Disease: Correlation with MDR1+Th17.1 Levels and the Effect of Prednisolone and 1α,25-Dihydroxyvitamin D3

Graft-versus-host disease (GVHD) remains one of the major complications after allogeneic hematopoietic stem cell transplantation that is mainly treated with glucocorticoids such as prednisolone. In this study the influence of monocyte subpopulations, prednisolone, and 1α,25-dihydroxyvitamin D3 (1α,25-(OH)₂D3) on the induction of a proinflammatory subset of Th17 cells (MDR⁺Th17.1) characterized by CCR6⁺CXCR3^hiCCR4^loCCR10^-CD161⁺ and stable expression of the multidrug resistance protein type 1 (MDR1) was investigated. Our results demonstrate that intermediate monocytes are increased in patients with acute GVHD, promoting the induction of proinflammatory MDR1⁺Th17.1 cells. Furthermore, prednisolone induces the development of MDR1⁺Th17.1 cells, whereas 1α,25-(OH)₂D3 acts as an anti-inflammatory, leading to diminished percentages of proinflammatory MDR1⁺Th17.1 cells in the presence of prednisolone after stimulation with the TLR4-ligand S100A8/S100A9. Moreover, 1α,25-(OH)₂D3 decreased the expression level of the targets JAK2 and CD74, both associated with T cell activation, in monocytes. Thus, in steroid-resistant GVHD, 1α,25-(OH)₂D3 could be an important regulator in monocyte-induced development of proinflammatory MDR1⁺Th17.1 cells and might therefore be a potential therapeutic agent in combination with glucocorticoids for GVHD treatment.

Is autoimmunity the Achilles' heel of cancer immunotherapy?

The emergence of immuno-oncology as the first broadly successful strategy for metastatic cancer will require clinicians to integrate this new pillar of medicine with chemotherapy, radiation, and targeted small-molecule compounds. Of equal importance is gaining an understanding of the limitations and toxicities of immunotherapy. Immunotherapy was initially perceived to be a relatively less toxic approach to cancer treatment than other available therapies-and surely it is, when compared to those. However, as the use of immunotherapy becomes more common, especially as first- and second-line treatments, immunotoxicity and autoimmunity are emerging as the Achilles' heel of immunotherapy. In this Perspective, we discuss evidence that the occurrence of immunotoxicity bodes well for the patient, and describe mechanisms that might be related to the induction of autoimmunity. We then explore approaches to limit immunotoxicity, and discuss the future directions of research and reporting that are needed to diminish it.

Vitamin D levels and their associations with survival and major disease outcomes in a large cohort of patients with chronic graft-vs-host disease

AIM

To identify the factors associated with vitamin D status in patients with chronic graft-vs-host disease (cGVHD) and evaluate the association between serum vitamin D (25(OH)D) levels and cGVHD characteristics and clinical outcomes defined by the National Institutes of Health (NIH) criteria.

METHODS

310 cGVHD patients enrolled in the NIH cGVHD natural history study (clinicaltrials.gov: NCT00092235) were analyzed. Univariate analysis and multiple logistic regression were used to determine the associations between various parameters and 25(OH)D levels, dichotomized into categorical variables: ≤20 and >20 ng/mL, and as a continuous parameter. Multiple logistic regression was used to develop a predictive model for low vitamin D. Survival analysis and association between cGVHD outcomes and 25(OH)D as a continuous as well as categorical variable: ≤20 and >20 ng/mL; <50 and ≥50 ng/mL, and among three ordered categories: ≤20, 20-50, and ≥50 ng/mL, was performed.

RESULTS

69 patients (22.3%) had serum 25(OH)D ≤20 ng/mL. Univariate analysis showed that supplement intake, nutritional status (severely malnourished, moderately malnourished, well-nourished), race (African-American, other), and estimated creatinine clearance (eCCr) were associated with 25(OH)D levels. A predictive model was developed based on supplement intake, nutritional status, race, and eCCr, accurately predicting 77.9% of patients with 25(OH)D ≤20 and 65.2% of those with 25(OH)D >20 ng/mL. No association was found between vitamin D and major cGVHD characteristics, but patients with 25(OH)D ≤20 ng/mL had somewhat decreased survival.

CONCLUSION

Nutritional status and adequate supplementation are important to maintain 25(OH)D >20 ng/mL in cGVHD patients. Intervention studies and more research is needed to reveal the underlying mechanism of vitamin D metabolism in cGVHD setting.

Vitamin D Deficiency in Pediatric Hematopoietic Stem Cell Transplantation Patients Despite Both Standard and Aggressive Supplementation

We recently reported that more than 70% of pediatric and young adult patients had a vitamin D (VD) deficiency at the time of their hematopoietic stem cell transplantation (HSCT). Moreover, VD deficiency was associated with inferior survival at 100 days after transplantation. The goal of the present study was to evaluate the VD requirements needed to maintain an optimal VD level (30 to 60 ng/mL) during the first 3 months after transplantation using real-time VD monitoring and personalized VD supplementation. We examined 2 cohorts in this study: cohort 1, the "preintervention" cohort (n = 35), who were treated according to National Kidney Foundation guidelines for VD therapy, and cohort 2, the "intervention" cohort (n = 25) who were treated with high-dose VD with an aggressive dosage increase in those who remained VD-insufficient. Results from cohort 1 showed that despite aggressive monitoring and VD supplementation, therapeutic vitamin D levels were difficult to achieve and maintain in HSCT recipients during the early post-transplantation period. Only 43% of cohort 1 achieved a therapeutic VD level, leading to our intervention in cohort 2. Outcomes improved in cohort 2, but still only 64% of cohort 2 patients achieved a therapeutic VD level despite receiving >200 IU/kg/day of VD enterally. The median VD level in patients who did achieve sufficient levels was 40 ng/mL, with only 1 patient in each cohort achieving a supratherapeutic but nontoxic level. These data indicate that standard guidelines for VD replacement are inadequate in HSCT recipients, and further work is needed to define more appropriate dosing in this clinical setting.

Vitamin D, D-dimer, Interferon γ, and sCD14 Levels are Independently Associated with Immune Reconstitution Inflammatory Syndrome: A Prospective, International Study

To determine the immunological profile most important for IRIS prediction, we evaluated 20 baseline plasma biomarkers in Acquired Immunodeficiency Syndrome (AIDS) patients initiating antiretroviral therapy (ART). Patients were enrolled in a randomized, placebo-controlled ART initiation trial in South Africa and Mexico to test whether maraviroc could prevent IRIS. Participants were classified prospectively as having IRIS within 6 months of ART initiation. Twenty plasma biomarkers were measured at study enrollment for 267 participants. Biomarkers were tested for predicting IRIS with adjustment for covariates chosen through forward stepwise selection. Sixty-two participants developed IRIS and of these 19 were tuberculosis (TB)-IRIS. Baseline levels of vitamin D and higher d-dimer, interferon gamma (IFNγ), and sCD14 were independently associated with risk of IRIS in multivariate analyses. TB-IRIS cases exhibited a distinct biosignature from IRIS related to other pathogens, with increased levels of C-reactive protein (CRP), sCD14, IFNγ, and lower levels of Hb that could be captured by a composite risk score. Elevated markers of Type 1 T helper (Th1) response, monocyte activation, coagulation and low vitamin D were independently associated with IRIS risk. Interventions that decrease immune activation and increase vitamin D levels warrant further study.