The role of vitamin D in hematologic disease and stem cell transplantation

Retinoic acid signaling in development and differentiation commitment and its regulatory topology

Retinoic acid (RA), the derivative of vitamin A/retinol, is a signaling molecule with important implications in health and disease. It is a well-known developmental morphogen that functions mainly through the transcriptional activity of nuclear RA receptors (RARs) and, uncommonly, through other nuclear receptors, including peroxisome proliferator-activated receptors. Intracellular RA is under spatiotemporally fine-tuned regulation by synthesis and degradation processes catalyzed by retinaldehyde dehydrogenases and P450 family enzymes, respectively. In addition to dictating the transcription architecture, RA also impinges on cell functioning through non-genomic mechanisms independent of RAR transcriptional activity. Although RA-based differentiation therapy has achieved impressive success in the treatment of hematologic malignancies, RA also has pro-tumor activity. Here, we highlight the relevance of RA signaling in cell-fate determination, neurogenesis, visual function, inflammatory responses and gametogenesis commitment. Genetic and post-translational modifications of RAR are also discussed. A better understanding of RA signaling will foster the development of precision medicine to improve the defects caused by deregulated RA signaling.

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.

Embryonic vitamin D deficiency programs hematopoietic stem cells to induce type 2 diabetes

Environmental factors may alter the fetal genome to cause metabolic diseases. It is unknown whether embryonic immune cell programming impacts the risk of type 2 diabetes in later life. We demonstrate that transplantation of fetal hematopoietic stem cells (HSCs) made vitamin D deficient in utero induce diabetes in vitamin D-sufficient mice. Vitamin D deficiency epigenetically suppresses Jarid2 expression and activates the Mef2/PGC1a pathway in HSCs, which persists in recipient bone marrow, resulting in adipose macrophage infiltration. These macrophages secrete miR106-5p, which promotes adipose insulin resistance by repressing PIK3 catalytic and regulatory subunits and down-regulating AKT signaling. Vitamin D-deficient monocytes from human cord blood have comparable Jarid2/Mef2/PGC1a expression changes and secrete miR-106b-5p, causing adipocyte insulin resistance. These findings suggest that vitamin D deficiency during development has epigenetic consequences impacting the systemic metabolic milieu.

Vitamin requirements during stem cell transplantation: a systematic review

Patients undergoing stem cell transplantation (SCT) are at high risk of malnutrition during the acute post-transplantation period. This systematic review aimed to collate and analyse the evidence for vitamin requirements post-SCT. A systematic search of five databases was conducted to include studies published until March 2021. The review utilised the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) framework. Inclusion criteria consisted of adults undergoing SCT who received vitamin supplementation or had their vitamin levels monitored up to 100 days post-SCT. Studies with paediatric patients or those that looked at vitamin derivates such as folinic acid were excluded. Main outcomes included vitamin deficiency and relevant clinical outcomes. Eleven studies (n = 11) were eligible for inclusion with five rated as neutral quality and six as positive quality. Five studies focused on allogenic SCT, two on autologous SCT and the remaining included a mix of both. Eight studies monitored vitamins levels post-SCT, and seven studies provided vitamin supplementation. Three studies (one provided supplementation) found a high prevalence of vitamin D deficiency (23-60%) prior to SCT. Findings indicate an unclear association between vitamin deficiency and post-SCT complications including acute graft-versus-host-disease, oral mucositis, and mortality. The GRADE certainty of evidence across these outcomes was low or very low. It is unclear if supplementation is needed during SCT, though assessing vitamin D levels prior to transplant should be considered. Further large observational studies or randomised control trials are required to establish vitamin requirements and guide supplementation protocols during SCT.

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).

FDA-Approved Drug Screening for Compounds That Facilitate Hematopoietic Stem and Progenitor Cells (HSPCs) Expansion in Zebrafish

Hematopoietic stem cells (HSCs) are a specialized subset of cells with self-renewal and multilineage differentiation potency, which are essential for their function in bone marrow or umbilical cord blood transplantation to treat blood disorders. Expanding the hematopoietic stem and progenitor cells (HSPCs) ex vivo is essential to understand the HSPCs-based therapies potency. Here, we established a screening system in zebrafish by adopting an FDA-approved drug library to identify candidates that could facilitate HSPC expansion. To date, we have screened 171 drugs of 7 categories, including antibacterial, antineoplastic, glucocorticoid, NSAIDS, vitamins, antidepressant, and antipsychotic drugs. We found 21 drugs that contributed to HSPCs expansion, 32 drugs’ administration caused HSPCs diminishment and 118 drugs’ treatment elicited no effect on HSPCs amplification. Among these drugs, we further investigated the vitamin drugs ergocalciferol and panthenol, taking advantage of their acceptability, limited side-effects, and easy delivery. These two drugs, in particular, efficiently expanded the HSPCs pool in a dose-dependent manner. Their application even mitigated the compromised hematopoiesis in an ikzf1^−/− mutant. Taken together, our study implied that the larval zebrafish is a suitable model for drug repurposing of effective molecules (especially those already approved for clinical use) that can facilitate HSPCs expansion.

Current practice in nutrition after allogeneic hematopoietic stem cell transplantation - Results from a survey among hematopoietic stem cell transplant centers

BACKGROUND

Allogeneic hematopoietic stem cell transplantation (alloHSCT) is frequently associated with impaired oral intake and malnutrition, which potentially increases morbidity and mortality. Therefore, nutrition is one of the major challenges in the post-transplant period.

METHODS

To document the current clinical approach in nutritional treatment, we designed a questionnaire concerning the current practice in nutrition after alloHSCT and distributed it to German speaking centers performing alloHSCT in Germany, Austria and Switzerland between November 2018 and March 2020. Twenty-eight (39%) of 72 contacted centers completed the survey, 23 from Germany, two from Austria and three from Switzerland, representing 50% of alloHSCT activity within the participating countries in 2018.

RESULTS

All centers reported having nutritional guidelines for patients undergoing alloHSCT, whereby 86% (n = 24) provided a low-microbial diet during the neutropenic phase. The criteria to start parenteral nutrition (PN) directly after alloHSCT seemed to be consistent, 75% (n = 21) of the corresponding centers started PN if the oral nutritional intake or the bodyweight dropped below a certain limit. In the setting of intestinal graft-versus-host disease (GvHD) the current practice appeared to be more heterogenous. About 64% (n = 18) of the centers followed a special diet, added food stepwise modulated by GvHD symptoms, while only four centers regularly stopped oral intake completely (intestinal GvHD grade >1). Half of the centers (54%, n = 15) applied a lactose-free diet, followed by 43% (n = 12) which provided fat- and 18% (n = 5) gluten-free food in patients with intestinal GvHD. Supplementation of micronutrients in acute intestinal GvHD patients was performed by 54% (n = 15) of the centers, whereas vitamin D (89%, n = 25) and vitamin B₁₂ (68%, n = 19) was added regularly independently of the presence of GvHD. Only 5 (18%) participating centers ever observed a food-associated infection during hospitalization, whereas food-associated infections were reported to occur more often in the outpatient setting (64%, n = 18).

CONCLUSION

The survey documented a general consensus about the need for nutritional guidelines for patients undergoing alloHSCT. However, the nutritional treatment in clinical practice (i.e. lactose-, gluten- or fat-free in intestinal GvHD) as well as the use of food supplements was very heterogeneous. In line with current general recommendations the centers seemed to focus on safe food handling practice rather than providing a strict neutropenic diet. More high-quality data are required to provide evidence-based nutrition to patients during and after alloHSCT.

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.

Reduced survival after autologous stem cell transplantation in myeloma and lymphoma patients with low vitamin D serum levels

High-dose chemotherapy (HDCT) with autologous stem cell transplantation (ASCT) is applied for consolidation in myeloma and relapsing lymphoma patients. Vitamin D (VitD) exerts effects during hematopoietic stem cell proliferation, differentiation and interactions with the immune system. VitD deficiency is frequent in patients with hematological malignancies, but its prognostic relevance after ASCT remains unclear. We investigated the effect of VitD serum levels in patients with lymphomas and myeloma at ASCT on progression-free (PFS) and overall survival (OS). The cohort (n = 183) was divided into two groups: 81 (44%) had VitD levels >52 nmol/L and 102 (56%) ≤52 nmol/L at ASCT. VitD levels >52 nmol/L were associated with better PFS (P = 0.0194) and OS (P = 0.011). Similarly, when evaluating myeloma patients alone, patients with lower VitD levels (≤52 nmol/L) had inferior PFS (P = 0.0412) and OS (P = 0.049). Finally, the multivariate analysis was consistent that varying VitD levels were significantly associated with OS (P = 0.0167), also when stratifying patients in groups with VitD levels > versus ≤52 nmol/L (P = 0.0421). Our data suggest that reduced serum VitD levels in myeloma and lymphoma patients undergoing HDCT/ASCT are associated with inferior outcome. Optimizing VitD levels before ASCT may be warranted.

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.

Prevalence of vitamin D deficiency in the pregnant women: an observational study in Shanghai, China

Background

Maternal vitamin D deficiency has been a worldwide concern in recent years. However the epidemiological data of vitamin D deficiency among large group of Chinese pregnant women is limited. This study is to evaluate the prevalence of vitamin D deficiency among pregnant women in Shanghai, China and to analyze the association of vitamin D status with some pregnancy outcomes (gestational diabetes and low birth weight).

Methods

A total of 34,417 pregnant women in Shanghai were included in this study from January 2014 to December 2017, and the serum 25-hydroxyvitamin D [25(OH)D] concentrations were measured at 16th week of gestation by electrochemiluminescence assay. Seventy five grams of glucose was used to conduct oral glucose tolerance test during 24-28th week of gestational in all enrolled persons and the birth weight of newborns was recorded.

Results

The median serum 25(OH) D concentration in the pregnant women during 4 years was 42.87 nmol/L (32.88–51.90 nmol/L). 9.9% of the population were severe vitamin D deficient [25(OH)D < 25 nmol/L], 60.1% were deficient [25 nmol/L ≤ 25(OH)D < 50 nmol/L], 28.4% were insufficient [50 nmol/L ≤ 25(OH)D < 75 nmol/L] and only 1.6% of the enrolled population reached the level of adequate [25(OH)D ≥ 75 nmol/L]. Serum 25(OH) D concentrations showed significant difference among seasons with the highest level in winter and the lowest level in summer. Women with advanced maternal age were more likely to have better vitamin D status compared with younger women. The 25(OH) D levels were significantly different among 2014–2017. The year of 2017 had the highest 25(OH) D level with the median serum concentration reaching 47.80 nmol/L (41.00–55.00 nmol/L), while the lowest appeared in 2016 which has median 25(OH) D concentration at 38.87 nmol/L (28.76–49.97 nmol/L). No relations were found between the 25(OH) D status and the rate of gestational diabetes or low birth weight of newborns.

Conclusion

Pregnant women in Shanghai were generally deficient in vitamin D status and the level of vitamin D was related to season and age. No evidence showed vitamin D deficiency in pregnant women contributes to the rate of gestational diabetes or low birth weight of newborns in this study. These results suggest that most of the pregnant women may need vitamin D supplementation to achieve adequate vitamin D level.

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.

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.

Additive Effects of VDBP and 1,25(OH)2D3 on the Viability and Apoptosis of Rheumatoid Arthritis Synovial Fibroblasts

AIM

This study is to investigate the additive effect of Vitamin D-binding protein (VDBP) and 1,25(OH)2D3 on the viability and apoptosis of synovial cells from patients with rheumatoid arthritis (RA).

METHODS

Synovial tissues and synovial fluid of patients with RA and osteoarthritis (OA) were collected. The expression of VDBP was analyzed with immunohistochemistry and ELISA. CCK-8 assay was applied to detect cell viability. Flow cytometry was used to analyze cell cycle and apoptosis.

RESULTS

Immunohistochemical results showed that the expression of VDBP in the synovium of RA patients was significantly lower than that of OA (P<0.05). Similarly, ELISA results presented a lower expression of VDBP in the synovial fluid of RA patients. The results of CCK-8 assay showed that both 1,25(OH)2D3 and VDBP significantly inhibited the viability of rheumatoid arthritis synovial fibroblasts (RASF) (P<0.05). The treatment with 1,25(OH)2D3+VDBP led to more significantly inhibited viability of RASF, compared with 1,25(OH)2D3 alone (P<0.05). The results of flow cytometry showed that 1,25(OH)2D3 and VDBP both promoted the apoptosis of RASF (P<0.05) and 1,25(OH)2D3+VDBP led to a higher proportion of RASF apoptosis, compared with 1,25(OH)2D3 alone (P<0.05). However, 1,25(OH)2D3 and VDBP had no significant effect on the cell cycle of RASF. Additionally, 1,25(OH)2D3 promoted the expression of VDBP in RASF, but not concentration-dependently.

CONCLUSION

VDBP is reduced in the synovial tissue and synovial fluid of RA patients and can inhibit viability of RASF and promote the apoptosis of RASF. The 1,25(OH)2D3 can upregulate the expression of VDBP in RASF. Additionally, VDBP can enhance the effects of 1,25(OH)2D3 on viability and apoptosis of RASF.

Vitamin D: is it important in haematopoietic stem cell transplantation? A review

Vitamin D has effects on several body systems, from well-established role in bone metabolism to emerging effects on the immune system. Increasing evidence supports an immunomodulatory effect including inhibition of the pro-inflammatory lymphocyte subsets while enhancing their anti-inflammatory counterpart, in favour of a more tolerogenic status. Vitamin D deficiency is increasingly recognised in association with autoimmune and inflammatory diseases, also with evidence from the field of asthma where vitamin D supplementation may overcome steroid resistance. In the HSCT setting, vitamin D deficiency has been variably associated with increased complications, including graft-versus-host disease (GvHD), with a potential impact on survival outcomes. In this review we provide an overview and critical appraisal of the current literature of the role of vitamin D (and its deficiency) in relation to immunity in both allogeneic and autologous HSCT settings. We conclude that the evidence base is mixed, but a greater understanding of the role of vitamin D in relation to immune reconstitution following HSCT is warranted. Given its potential benefits, its inexpensive cost and favourable side effect profile, consideration of vitamin D levels and its supplementation could be easily incorporated into prospective studies in GvHD, including clinical trials of novel therapeutics, supportive care and biomarkers.

Vitamin D and its receptor polymorphisms: New possible prognostic biomarkers in leukemias

Several factors such as chromosomal translocations, gene mutations, and polymorphisms are involved in the pathogenesis of leukemia/lymphoma. Recently, the role of vitamin D (VD) and vitamin D receptor (VDR) polymorphisms in hematologic malignancies has been considered. In this review, we examine the possible role of VD levels, as well as VDR polymorphisms as prognostic biomarkers in leukemia/lymphoma. Relevant English language literature were searched and retrieved from Google Scholar search engine (1985-2017). The following keywords were used: vitamin D, vitamin D receptor, leukemia, lymphoma, and polymorphism. Increased serum levels of VD in patients with leukemia are associated with a better prognosis. However, low VD levels are associated with a poor prognosis, and VDR polymorphisms in various leukemias can have prognostic value. VD biomarker can be regarded as a potential prognostic factor for a number of leukemias, including acute myeloblastic leukemia (AML), chronic lymphoblastic leukemia (CLL), and diffuse large B-cell lymphoma (DLBCL). There is a significant relationship between different polymorphisms of VDR (including Taq I and Fok I) with several leukemia types such as ALL and AML, which may have prognostic value.

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.

Variability of contribution of vitamin D receptor gene polymorphisms to outcome of HLA-matched sibling allogeneic bone marrow transplantation

Graft-versus-host disease (GVHD) remains one of the major complications of hematopoietic stem cell transplantation (HSCT). Several etiological factors were investigated. Among these, vitamin D and hence its receptor (VDR) gene polymorphisms have gained much interest; however, the results are still controversial. Using PCR-RFLP, we genotyped VDR polymorphisms FokI (rs10735810), ApaI (rs7975232), and Taq1 (rs731236) in 80 patient/donor pairs according to DNA availability. No association was encountered between VDR polymorphisms and GVHD. Neither was there any impact on survival. Only grade II-IV acute GVHD was associated with inferior overall (p = .01), but not disease-free survival. The controversy between our results and the literature may be attributed to marked variability in the relative distribution of VDR genotypes in different populations. Also different environmental factors, including exposure to sun, may ensure vitamin D sufficiency nullifying the impact of VDR polymorphisms.

1,25-OH2 vitamin D3 and AKT-inhibition increase glucocorticoid induced apoptosis in a model of T-cell acute lymphoblastic leukemia (ALL)

In acute lymphoblastic leukemia (ALL), steroid resistance and hypovitaminosis D are both associated with a poor prognosis. We show that methylprednisolone, calcitriol and the AKT-inhibitor MK-2206 have a synergistic effect on the apoptosis of steroid resistant T-ALL cells. Compared to methylprednisolone monotherapy, calcitriol increases methylprednisolone induced apoptosis dose-dependently (1.37-1.92-fold; p < 0.05). Pre-incubation with calcitriol increases the apoptotic effect of MK-2206 even further (3.6-fold; p < 0.05). It also potentiates synergism between MK-2206 and methylprednisolone (vehicle control 38% vs. calcitriol 58%, p < 0.01). The combination of calcitriol and AKT inhibition should be investigated further as treatment options for steroid resistance in T-ALL.

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.

Hodgkin Lymphoma has a seasonal pattern of incidence and mortality that depends on latitude

Seasonal variations in incidence and mortality after a Hodgkin lymphoma (HL) diagnosis have been previously described with partly conflicting results. The goal of this analysis is to provide a comprehensive analysis of these seasonal variations. In total, 41,405 HL cases diagnosed between 1973 and 2012 in the 18 Surveillance, Epidemiology, and End Results registries were included. Cosinor analysis and Cox proportional-hazards models were employed to analyze seasonality of incidence and mortality, respectively. HL shows a sinusoid seasonal incidence pattern (p < 0.001). Estimated incidence in March is 15.4% [95%-CI: 10.8-20.0] higher than in September. This sinusoid pattern is more pronounced at higher latitudes (p = 0.023). The risk of dying within the first three years after a HL diagnosis in winter is significantly increased compared to a HL diagnosis in summer at higher latitudes (HR = 1.082 [95%-CI: 1.009-1.161], p = 0.027). Furthermore, increasing northern latitude increases the additional mortality risk conferred by a diagnosis in winter (pinteraction0.033). The seasonality patterns presented here provide epidemiological evidence that Vitamin D might play a protective role in HL. Further evidence on the direct association between Vitamin D levels and the clinical course of HL needs to be collected to advance the understanding of the role of Vitamin D in HL.

Pretransplant Vitamin D Deficiency Is Associated With Higher Relapse Rates in Patients Allografted for Myeloid Malignancies

Purpose Vitamin D (VitD) deficiency is common in patients with hematologic malignancies undergoing allogeneic transplantation (alloSCT), but its prognostic relevance is unclear. Patients and Methods The impact of pretransplant VitD status on overall survival, relapse mortality, and nonrelapse mortality was investigated retrospectively in a cohort of 492 patients undergoing alloSCT at our center from 2002 to 2013. VitD deficiency was defined as a serum level of 25-hydroxyvitamin D3 < 20 ng/mL (equivalent to < 50 nM) before alloSCT and was assessed using accredited laboratory methods and a standard chemiluminescent immunoassay. Results were validated in an independent cohort of 398 patients diagnosed with myeloid malignancies. Results A total of 396 (80%) and 348 (87%) patients had VitD deficiency before alloSCT in the training and validation cohort, respectively. In the training cohort, VitD deficiency was significantly associated with inferior overall survival (hazard ratio [HR], 1.78; P = .007) in multivariable analysis. This was due to a higher risk of relapse (HR, 1.96; P = .006) rather than nonrelapse mortality. A significant association of pretransplant VitD deficiency with higher relapse rates was observed only in patients diagnosed with myeloid (HR, 2.55; P = .014) but not with lymphatic diseases (HR, 1.60; P = .147). A similar impact of pretransplant VitD deficiency on relapse risk in myeloid diseases was also observed in an independent patient cohort (HR, 2.60; P = .017). Validation of the effect of VitD deficiency on relapse in patients with myeloid malignancies was successful. Conclusion Pretransplant VitD deficiency was associated with a higher risk of relapse in patients allografted for myeloid malignancies. Prospective studies on VitD status and correction of VitD deficiency in the setting of alloSCT are highly warranted.

Role of Vitamin A/Retinoic Acid in Regulation of Embryonic and Adult Hematopoiesis

Vitamin A is an essential micronutrient throughout life. Its physiologically active metabolite retinoic acid (RA), acting through nuclear retinoic acid receptors (RARs), is a potent regulator of patterning during embryonic development, as well as being necessary for adult tissue homeostasis. Vitamin A deficiency during pregnancy increases risk of maternal night blindness and anemia and may be a cause of congenital malformations. Childhood Vitamin A deficiency can cause xerophthalmia, lower resistance to infection and increased risk of mortality. RA signaling appears to be essential for expression of genes involved in developmental hematopoiesis, regulating the endothelial/blood cells balance in the yolk sac, promoting the hemogenic program in the aorta-gonad-mesonephros area and stimulating eryrthropoiesis in fetal liver by activating the expression of erythropoietin. In adults, RA signaling regulates differentiation of granulocytes and enhances erythropoiesis. Vitamin A may facilitate iron absorption and metabolism to prevent anemia and plays a key role in mucosal immune responses, modulating the function of regulatory T cells. Furthermore, defective RA/RARα signaling is involved in the pathogenesis of acute promyelocytic leukemia due to a failure in differentiation of promyelocytes. This review focuses on the different roles played by vitamin A/RA signaling in physiological and pathological mouse hematopoiesis duddurring both, embryonic and adult life, and the consequences of vitamin A deficiency for the blood system.

Revisiting nutritional support for allogeneic hematologic stem cell transplantation-a systematic review

In 2009, the American Society of Parenteral and Enteral Nutrition and its European counterpart (Euopean Society for Parenteral and Enteral Nutrition) published guidelines regarding nutritional support of patients with hematologic stem cell transplantation. Our aim was to do an up-to-date literature review regarding benefit of nutritional interventions and treatment recommendations. We searched MEDLINE, EMBASE and Cochrane Library for interventional and observational clinical studies. We extracted data based on a predefined case report form and assessed bias. Out of 459 potential abstracts, 13 studies of mostly moderate quality with a total of 18 167 patients were included. Two very large trials reported negative associations of malnutrition and survival, transplant-related mortality and relapse risk. Some trials found enteral nutrition (EN) to be as effective as parenteral nutrition (PN) with lower complication rates. In addition, EN was associated with better survival, less acute GvHD and faster neutrophil recovery. A neutropenic diet was not superior regarding overall survival, but in contrast resulted in higher infection risk. Current moderate quality studies show negative associations of malnutrition and clinical outcomes, with EN being superior to PN. There was no benefit of neutropenic diets. Large, randomized controlled studies are needed to better understand optimal nutritional support in this patient population.

A Functional Bioluminescent Zebrafish Screen for Enhancing Hematopoietic Cell Homing

To discover small molecules that modulate hematopoietic cell homing after adoptive transfer, we created a transgenic zebrafish expressing firefly luciferase downstream of the ubiquitin promoter (ubi:luc) to serve as a hematopoietic donor. Bioluminescence imaging (BLI) was used to detect and follow ubi:luc hematopoietic cells that homed to the marrow as early as 1 day post-transplant. BLI was able to detect the biological effect of prostaglandin E₂ on early homing/engraftment of donor hematopoietic cells. This system was utilized in a functional screen of small molecules to enhance homing/engraftment. We discovered a phytosterol, ergosterol, that could increase hematopoietic cell homing in zebrafish and mice. In addition, ergosterol increased CXCR4 expression and promoted expansion of Lin⁻SCA-1⁺KIT⁺ cells in vitro. We have demonstrated the utility of in vivo BLI to non-invasively monitor donor hematopoietic cell activity in adult zebrafish as a functional screen for mediators of cellular homing.

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Bioluminescent imaging (BLI) can track engrafting hematopoietic cells

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BLI can be used for screening of enhancers of hematopoietic cell homing

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Using BLI, ergosterol was found to increase hematopoietic cell homing

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Ergosterol affects hematopoietic progenitor migration, growth, and viability in vitro

Could Vitamin D Analogues Be Used to Target Leukemia Stem Cells?

Leukemic stem cells (LSCs) are defined as cells that possess the ability to self-renew and give rise to the differentiated cancer cells that comprise the tumor. These LSCs seem to show chemo-resistance and radio-resistance leading to the failure of conventional cancer therapies. Current therapies are directed at the fast growing tumor mass leaving the LSC fraction untouched. Eliminating LSCs, the root of cancer origin and recurrence, is considered to be a hopeful approach to improve survival or even to cure cancer patients. In order to achieve this, the characterization of LSCs is a prerequisite in order to develop LSC-based therapies to eliminate them. Here we review if vitamin D analogues may allow an avenue to target the LSCs.

The Effect of Bone Marrow Mesenchymal Stem Cells on Vitamin D3 Induced Monocytic Differentiation of U937 Cells

PURPOSE

Mesenchymal stem cells (MSCs) are key components of the hematopoietic stem cells (HSCs) niche. They control the process of hematopoiesis by secreting regulatory cytokines, growth factors and expression of important cell adhesion molecules for cell-tocell interactions. In this research, we have investigated the effect of bone marrow derived MSCs on monocytic differentiation of U937 cells line.

METHODS

U937 cells were cultured in both direct co-culture with MSCs and MSCs conditioned medium (C.M) driven. This study used 1,25-dihydroxyvitamin D3(VitD3) as inductor of monocytic differentiation and U937 cells treated with VitD3 morphology was examined by Wright Giemsa staining. CD14 monocytic differentiation marker was measured by flow cytometry and monocytic gene expression was assessed by real time polymerase chain reaction (RT PCR).

RESULTS

The results of flow cytometric analysis showed that CD14 expression of U937 increased. The higher effect of MSCs co-culture on CD14 expression in U937 cells was observed, compared to the conditioned medium. Among ten monocytic related genes which were screened that was observed increase in 5 genes in which CXCR4 and CSF2RA showed significant increase.

CONCLUSION

The results obtained show that MSCs have supportive effect on the monocytic differentiation of U937 cells. However, a distinct mechanism of that remains unclear.

The Effect of Bone Marrow Mesenchymal Stem Cells on Vitamin D3 Induced Monocytic Differentiation of U937 Cells

PURPOSE

Mesenchymal stem cells (MSCs) are key components of the hematopoietic stem cells (HSCs) niche. They control the process of hematopoiesis by secreting regulatory cytokines, growth factors and expression of important cell adhesion molecules for cell-tocell interactions. In this research, we have investigated the effect of bone marrow derived MSCs on monocytic differentiation of U937 cells line.

METHODS

U937 cells were cultured in both direct co-culture with MSCs and MSCs conditioned medium (C.M) driven. This study used 1,25-dihydroxyvitamin D3(VitD3) as inductor of monocytic differentiation and U937 cells treated with VitD3 morphology was examined by Wright Giemsa staining. CD14 monocytic differentiation marker was measured by flow cytometry and monocytic gene expression was assessed by real time polymerase chain reaction (RT PCR).

RESULTS

The results of flow cytometric analysis showed that CD14 expression of U937 increased. The higher effect of MSCs co-culture on CD14 expression in U937 cells was observed, compared to the conditioned medium. Among ten monocytic related genes which were screened that was observed increase in 5 genes in which CXCR4 and CSF2RA showed significant increase.

CONCLUSION

The results obtained show that MSCs have supportive effect on the monocytic differentiation of U937 cells. However, a distinct mechanism of that remains unclear.

The Potential of Vitamin D-Regulated Intracellular Signaling Pathways as Targets for Myeloid Leukemia Therapy

The current standard regimens for the treatment of acute myeloid leukemia (AML) are curative in less than half of patients; therefore, there is a great need for innovative new approaches to this problem. One approach is to target new treatments to the pathways that are instrumental to cell growth and survival with drugs that are less harmful to normal cells than to neoplastic cells. In this review, we focus on the MAPK family of signaling pathways and those that are known to, or potentially can, interact with MAPKs, such as PI3K/AKT/FOXO and JAK/STAT. We exemplify the recent studies in this field with specific relevance to vitamin D and its derivatives, since they have featured prominently in recent scientific literature as having anti-cancer properties. Since microRNAs also are known to be regulated by activated vitamin D, this is also briefly discussed here, as are the implications of the emerging acquisition of transcriptosome data and potentiation of the biological effects of vitamin D by other compounds. While there are ongoing clinical trials of various compounds that affect signaling pathways, more studies are needed to establish the clinical utility of vitamin D in the treatment of cancer.