Relationship between serum 25-hydroxyvitamin D and inflammatory cytokines in paediatric sickle cell disease

Investigation of serum level relationship of pro-inflammatory and anti-inflammatory cytokines with vitamin D among healthy Ghanaian population

BACKGROUND

The interplay between vitamin D status and inflammatory cytokines in a supposedly sufficient sunshine environment has not well been evaluated. The study sought to determine their association.

METHODS

This cross-sectional study involved 500 healthy adult blood donors from some selected hospitals in Ghana enrolled from June to November 2016. Venous blood samples were obtained from participants, 25(OH)D, TNF-alpha, IFN-gamma, and IL 10 were measured using enzyme linked immunosorbent assay (ELISA) technique. Serum levels of 25(OH)D < 20ng/ml were classified as being deficient or low.

RESULTS

The average age of the participants was 27.97 years. No statistically significant association was established between 25(OH) D status, mean age (p = 0.1693), and gender (p = 0.5461) of study participants. Similarly, the median 25(OH) D (p = 0.8392), IL-10 (p = 0.5355), TNF-alpha (p = 0.9740), and IFN-gamma (p = 0.6908) were not significantly different across gender. There was a significantly increased levels of TNF-alpha (p < 0.0001) and IFN-gamma (p < 0.0001) among participants with 25(OH) D deficiency compared to those without deficiency. Concurrently, participants with 25(OH)D deficiency had a significantly reduced levels of IL-10 (p < 0.0001) compared to those without 25 (OH) D deficiency. The most accurate biochemical markers for identifying 25 (OH) D deficiency were IFN-gamma (AUC = 0.879; p < 0.0001) followed by TNF-gamma (AUC = 0.849; p < 0.0001) and IL-10 (AUC = 0.707; p < 0.0001).

CONCLUSION

There was a significant association between vitamin D levels and pro-inflammatory cytokines (TNF-alpha, IFN-gamma) and anti-inflammatory cytokine (IL 10) among healthy Ghanaian populace.

Vitamin D deficiency in relation with the systemic and central inflammation during multiple sclerosis

Background

During the last decade, vitamin D (VitD) has become a topic of interest in immune regulation, especially in multiple sclerosis (MS) disease. Amongst the wide range of effects reported for this vitamin on the immune system, a regulatory role on cytokines production has been described. Our aim is to analyze the status of VitD and its correlation with the circulating inflammation and the intrathecal humoral response during MS.

Methods

We analyzed samples of 318 individuals: 108 MS patients and 210 controls. Determination of 25-(OH) VitD3 level in serum was made using electrochemiluminescence method. Circulating inflammatory cytokines (IL-6, IL-8, IL-10, TNF-a, IL12p70 and IL-1b) were investigated using Cytometer Bead Array Technology. The central humoral response was characterized using CSF isofocusing test and IgG Index calculation.

Results

As expected, mean value of VitD was significantly lower in MS group (26 nmol/L) than in control group (34.75 nmol/L) (p=0.002), with a severe deficiency in 67% of MS patients. Mean value of VitD was significantly lower in MS female patients. Regarding cytokines, mean value of TNFa was significantly higher in MS patients with oligoclonal bands of IgG in the CSF. IL6 was positively correlated with IgG level in serum of MS patients.

Conclusions

Our results support the association of VitD deficiency with MS, especially in female patients of our region. However, the vitamin level seems to not correlate with inflammatory cytokines nor with disability. Interestingly, TNFa and IL6 levels were correlated with the intrathecal synthesis of IgG and the circulating IgG level, respectively.

Anti-inflammatory cytokines in sickle cell disease

Sickle cell disease (SCD) is a well-studied monogenetic disease with an established chronic inflammatory component. The paradigm shift towards inflammation has made the pathophysiology of SCD even more complex. Studies have shown that an imbalance between the pro-inflammatory and anti-inflammatory cytokines in SCD exists; however, the reports are skewed toward the pro-inflammatory mediators. We enumerate recent in vitro and in vivo studies on anti-inflammatory cytokines in SCD patients, and discuss the biology of anti-inflammatory cytokines including the already reported IL-2, TGF-β, and IL-10 as well as the recently discovered IL-27, IL-35 and IL-37. This review will improve the understanding of the pathophysiology of SCD and aid in the search of new therapeutic options for patients with SCD.

The Association between Standardized Serum 25-Hydroxyvitamin D Concentration and Risk of Anemia: A Population-Based Cross-Sectional Study

The relationship between standardized serum 25-hydroxyvitamin D (25(OH)D) concentration and incident anemia in the United States (U.S.) is unclear. The purpose of our study was to examine the association between serum 25(OH)D and anemia risk. We performed a cross-sectional analysis of the U.S. population participating in the National Health and Nutrition Examination Survey (NHANES) between 2001 and 2018. A generalized linear model and restricted cubic spline (RCS) plot curve were constructed to assess the relationship between serum 25(OH)D concentration and anemia incidence. Additionally, the association between serum 25(OH)D concentration and red blood cell (RBC) count and hemoglobin (HB) levels was investigated using generalized additive models with smooth functions. Subgroup analysis also was performed. A total of 29933 individuals were included in our research. After adjusting for known confounding variables, compared with the lowest quartile, the odds ratios (ORs) with 95% confidence intervals (CIs) for association of serum 25(OH)D with anemia across the second, third, and fourth quartiles were 0.735 (0.651, 0.829), 0.527 (0.461, 0.602), and 0.696 (0.611, 0.792), respectively. Serum 25(OH)D concentration was associated with anemia risk in a U-shaped pattern, as shown by an RCS plot (P for nonlinearity <0.001). In addition, RBC count and Hb levels initially increased and then decreased as serum 25(OH)D levels increased. Serum 25(OH)D concentration and risk of anemia are associated with a U-shaped curve in the U.S. general population. Serum 25(OH)D concentration in the range 59.7-70.3 nmol/l was associated with anemia incidence <1. Therefore, the risk of anemia can be reduced by close monitoring and appropriate vitamin D supplementation.

Vitamin D Supplementation: Association With Serum Cytokines in Pediatric Hematopoietic Stem Cell Transplantation

Vitamin D deficiency is prevalent in pediatric patients presenting for hematopoietic stem cell transplantation (HSCT) and has been linked to poor clinical outcomes. Using the data from a randomized control trial, in this paper we explore the effects of vitamin D supplementation on circulating cytokine levels during pediatric HSCT (www.clinicaltrials.gov as NCT03176849). A total of 41 children, 20 received Stoss therapy and 21 children received standard of care vitamin D supplementation. Levels of 25(OH)D and 20 cytokines were assessed at baseline and day +30. Significantly (P < 0.05) higher levels of mostly proinflammatory cytokines, FGF, GCSF, TNFα, IL-2, IL-6, IP10 were detected pre-transplant for patients with low compared to those with normal vitamin D levels. In sex stratified models that compare changes in cytokines between Stoss vs. standard of care, females in the Stoss group show greater changes in mostly pro -inflammatory cytokines- IP-10 (P = 0.0047), MIG (P = 0.009), and RANTES (P = 0.0047), IL-2R (P = 0.07) and IL-6(P = 0.069). Despite a small sample size, these findings suggest vitamin D deficiency affects the pre-transplant cytokine milieu and higher doses of vitamin D (Stoss therapy) appears to influence proinflammatory cytokine responses in a sex specific manner during pediatric HSCT. Larger clinical trials are warranted to validate these results.

Interleukin 6 as a marker of severe bacterial infection in children with sickle cell disease and fever: a case-control study

Background

Etiological diagnosis of fever in children with sickle cell disease (SCD) is often challenging. The aim of this study was to analyze the pattern of inflammatory biomarkers in SCD febrile children and controls, in order to determine predictors of severe bacterial infection (SBI).

Methods

A prospective, case–control study was carried out during 3 years, including patients younger than 18 years with SCD and fever (cases) and asymptomatic steady-state SCD children (controls). Clinical characteristics and laboratory parameters, including 10 serum proinflammatory cytokines (IL-1β, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12p70, IL-17a, IFN-γ and TNF-α) and comparisons among study subgroups were analyzed.

Results

A total of 137 patients (79 cases and 58 controls) were included in the study; 78.5% males, median age 4.1 (1.7–7.5) years. Four cases were diagnosed with SBI, 41 viral infection (VI), 33 no proven infection (NPI) and 1 bacterial-viral coinfection (the latter excluded from the subanalyses). IL-6 was significantly higher in patients with SBI than in patients with VI or NPI (163 vs 0.7 vs 0.7 pg/ml, p < 0.001), and undetectable in all controls. The rest of the cytokines analyzed did not show any significant difference. The optimal cut-off value of IL-6 for the diagnosis of SBI was 125 pg/mL, with high PPV and NPV (PPV of 100% for a prevalence rate of 5, 10 and 15% and NPV of 98.7%, 97.3% and 95.8% for those prevalences rates, respectively).

Conclusion

We found that IL-6 (with a cut-off value of 125 pg/ml) was an optimal marker for SBI in this cohort of febrile SCD children, with high PPV and NPV. Therefore, given its rapid elevation, IL-6 may be useful to early discriminate SCD children at risk of SBI, in order to guide their management.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-021-06470-4.

A Potential Role of Vitamin D on Platelet Leukocyte Aggregation and Pathological Events in Sepsis: An Updated Review

Vitamin D deficiency and sepsis are both significant global health problems. Insufficient vitamin D is considered to be a pathogenically relevant factor of sepsis-related deaths; however, a causal relationship has not yet been demonstrated. Recently, vitamin D has been an exciting field of research owing to the identification of vitamin D receptors on many extra skeletal tissues and cells, suggesting an unexpected role on body physiology, beyond its effects on bone homeostasis. However, while the role of vitamin D on bone health is widely understood and has been successfully translated into clinical applications and public health policies, recent evidence supporting its role in other physiological and pathological processes has not been fully established. In sepsis, there is an induction of local intracellular vitamin D activity by most immune cells, including lymphocytes, macrophages, neutrophils, and dendritic cells, as well as vascular endothelial cells, to ensure efficient clearance of infective microorganisms and mediate anti-inflammatory and tolerogenic effects. The literature suggests an association between low vitamin D levels and sepsis, but clinical trials have yielded contradictory results. A greater understanding of this role may improve disease management. This article reviews the available knowledge regarding vitamin D in immune function, emerging literature regarding the association between its deficiency and sepsis, as well as presenting its potential effect on platelet leukocyte aggregations (PLAs), a significant pathology in sepsis. It also summarizes clinical trials involving vitamin D supplementation during critical illness and sepsis and addresses the impact of relevant factors of sepsis pathogenesis on the efficacy of vitamin D supplementation, which could contribute to the reported inconsistencies. Looking ahead, further studies are required to uncover the possible modulatory relationship between vitamin D and sepsis to define better cut-offs for its levels, proper timing of its administration, and the optimum dosage for best management.

Nutritional perspectives on sickle cell disease in Africa: a systematic review

BACKGROUND

Sickle cell disease (SCD) is an inherited blood disorder that predominantly affects individuals in sub-Saharan Africa. However, research that elucidates links between SCD pathophysiology and nutritional status in African patients is lacking. This systematic review aimed to assess the landscape of studies in sub-Saharan Africa that focused on nutritional aspects of SCD, and highlights gaps in knowledge that could inform priority-setting for future research.

METHODS

The study was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. Inclusion criteria comprised original, peer-reviewed research published between January 1995 and November 2020 involving individuals in Africa with any phenotypic variant of SCD and at least one nutritional status outcome. Nutritional status outcomes were defined as those that assessed dietary intakes, growth/anthropometry, or nutritional biomarkers. Databases used were Ovid Embase, Medline, Biosis and Web of Science.

RESULTS

The search returned 526 articles, of which 76 were included in the final analyses. Most investigations (67%) were conducted in Nigeria. Studies were categorized into one of three main categories: descriptive studies of anthropometric characteristics (49%), descriptive studies of macro- or micronutrient status (41%), and interventional studies (11%). Findings consistently included growth impairment, especially among children and adolescents from sub-Saharan Africa. Studies assessing macro- and micronutrients generally had small sample sizes and were exploratory in nature. Only four randomized trials were identified, which measured the impact of lime juice, long-chain fatty acids supplementation, ready-to-use supplementary food (RUSF), and oral arginine on health outcomes.

CONCLUSIONS

The findings reveal a moderate number of descriptive studies, most with small sample sizes, that focused on various aspects of nutrition and SCD in African patients. There was a stark dearth of interventional studies that could be used to inform evidence-based changes in clinical practice. Findings from the investigations were generally consistent with data from other regional settings, describing a significant risk of growth faltering and malnutrition among individuals with SCD. There is an unmet need for clinical research to better understand the potential benefits of nutrition-related interventions for patients with SCD in sub-Saharan Africa to promote optimal growth and improve health outcomes.

Comparison of two vitamin D supplementation strategies in children with sickle cell disease: a randomized controlled trial

Previously, we showed that nearly 70% of children followed in our sickle cell disease (SCD) clinic were vitamin D- deficient and had low vitamin intake with poor use of supplements. We compared the change in serum 25-hydroxyvitamin D [25(OH)D], safety and clinical impact of two vitamin D supplementation regimens in children with SCD. Children (5-17 years, all genotypes) were randomized to a single bolus of vitamin D₃ (300 000 IU; n = 18) or placebo (n = 20). All children received a prescription for daily 1 000 IU vitamin D₃ . Serum 25(OH)D and calcium, urinary calcium/creatinine ratio, musculoskeletal pain, quality of life, haematology and bone markers were assessed at baseline and three months post intervention. Bolus administration led to a greater rise in 25(OH)D levels from baseline compared to placebo (20 ± 16 nmol/l vs. 2 ± 19 nmol/l; P = 0·003) and correction of vitamin D deficiency. No hypercalcaemia nor hypercalciuria occurred during the study, but more children in the bolus group experienced gastrointestinal symptoms within the first month (P = 0·04). There were no differences between groups for other outcomes. The use of a high-dose vitamin D bolus combined with daily 1 000 IU vitamin D₃ was more efficient in raising 25(OH)D levels than daily supplementation alone in children with SCD.

The COVID-19 Pandemic: Does Our Early Life Environment, Life Trajectory and Socioeconomic Status Determine Disease Susceptibility and Severity?

A poor socioeconomic environment and social adversity are fundamental determinants of human life span, well-being and health. Previous influenza pandemics showed that socioeconomic factors may determine both disease detection rates and overall outcomes, and preliminary data from the ongoing coronavirus disease (COVID-19) pandemic suggests that this is still true. Over the past years it has become clear that early-life adversity (ELA) plays a critical role biasing the immune system towards a pro-inflammatory and senescent phenotype many years later. Cytotoxic T-lymphocytes (CTL) appear to be particularly sensitive to the early life social environment. As we understand more about the immune response to SARS-CoV-2 it appears that a functional CTL (CD8+) response is required to clear the infection and COVID-19 severity is increased as the CD8+ response becomes somehow diminished or exhausted. This raises the hypothesis that the ELA-induced pro-inflammatory and senescent phenotype may play a role in determining the clinical course of COVID-19, and the convergence of ELA-induced senescence and COVID-19 induced exhaustion represents the worst-case scenario with the least effective T-cell response. If the correct data is collected, it may be possible to separate the early life elements that have made people particularly vulnerable to COVID-19 many years later. This will, naturally, then help us identify those that are most at risk from developing the severest forms of COVID-19. In order to do this, we need to recognize socioeconomic and early-life factors as genuine medically and clinically relevant data that urgently need to be collected. Finally, many biological samples have been collected in the ongoing studies. The mechanisms linking the early life environment with a defined later-life phenotype are starting to be elucidated, and perhaps hold the key to understanding inequalities and differences in the severity of COVID-19.

Association between pre-chemotherapy serum levels of vitamin D and clinicopathologic findings in gastric cancer

BACKGROUND

To examine the serum levels of vitamin D in newly diagnosed gastric cancer (GC) patients compared with normal subjects and any possible association with prognostic variables.

METHODS

One-hundred subjects (50 GC and 50 controls) were enrolled and serum vitamin D levels were assessed using ELISA. Based on two definitions, vitamin D was classified as a sufficient level (≥30 ng/dL) and optimal level (25-80 ng/dL). The χ²and unpaired t-test was used for data analysis with a significance level of 0.05.

RESULTS

The mean serum levels of vitamin D in patients and controls were 26.86 (±14.6) and 31.72 (±13.4), respectively (P=0.09). The prevalence of vitamin D insufficiency and deficiency was higher in GC cases than controls (P=0.045 if sufficient level ≥30 and P=0.065 if sufficient level ≥25). According to histological grade analysis, grade 3 patients (poorly differentiated) were found with significantly lower vitamin D concentrations in serum than grade 1 and 2 subjects (22.25 vs 33.29 ng/dL, P=0.021). No significant differences were observed between the two groups in pathological tumor-node-metastasis (pTNM) stages, distant metastasis, and location of the tumor.

CONCLUSION

Higher prevalence of vitamin D insufficiency and deficiency in GC patients may reflect its role in malignancy; however, further studies are needed to confirm this relationship and any possible benefits to the patients.

The Effect of Vitamin D3 Supplementation on Hepcidin, Iron, and IL-6 Responses after a 100 km Ultra-Marathon

Deficiencies in iron and vitamin D are frequently observed in athletes. Therefore, we examined whether different baseline vitamin D₃ levels have any impact on post-exercise serum hepcidin, IL-6 and iron responses in ultra-marathon runners. In this randomized control trial, the subjects (20 male, amateur runners, mean age 40.75 ± 7.15 years) were divided into two groups: experimental (VD) and control (CON). The VD group received vitamin D₃ (10,000 UI/day) and the CON group received a placebo for two weeks before the run. Venous blood samples were collected on three occasions-before the run, after the 100 km ultra-marathon and 12 h after the run-to measure iron metabolism indicators, hepcidin, and IL-6 concentration. After two weeks of supplementation, the intervention group demonstrated a higher level of serum 25(OH)D than the CON group (27.82 ± 5.8 ng/mL vs. 20.41 ± 4.67 ng/mL; p < 0.05). There were no differences between the groups before and after the run in the circulating hepcidin and IL-6 levels. The decrease in iron concentration immediately after the 100-km ultra-marathon was smaller in the VD group than CON (p < 0.05). These data show that various vitamin D₃ status can affect the post-exercise metabolism of serum iron.

The association between vitamin D deficiency and hospitalization outcomes in pediatric patients with sickle cell disease

BACKGROUND

While there is a known association between low vitamin D levels and increased chronic pain in patients with Sickle Cell Disease (SCD), there are no reported studies evaluating the relationship of vitamin D levels and hospitalization outcomes in this population. The aim of this study was to assess this relationship with hospitalization outcomes defined as the number of emergency room (ER) visits, hospital admissions for pain crisis, and length of hospital stay.

DESIGN

A retrospective chart review of all pediatric patients with SCD (1-21 years old) was performed from January 2015 to January 2016 in an urban-based hospital setting (n = 134). Those with at least one reported Vitamin D level who maintained follow up during the time studied were enrolled (n = 90). Patient hospitalizations rates were compared between vitamin D deficiency (<20 ng/ml) and sufficiency (>20 ng/ml).

RESULTS

Patients with both SCD and vitamin D deficiency were more likely to have at least one Emergency Room visit (p < 0.01), at least one admission for pain crisis (p < 0.01), and a longer length of admission (p < 0.0001) when compared to patients with SCD and sufficient vitamin D levels.

CONCLUSION

There is a significant association between vitamin D levels of <20 ng/ml and the number of ER visits, hospital admissions for pain crisis, and length of stay in patients with SCD. Further research is required to assess if correcting vitamin D levels may improve hospitalization outcomes in this population.

Low Vitamin D Serum Level Is Associated with HDL-C Dyslipidemia and Increased Serum Thrombomodulin Levels of Insulin-Resistant Individuals

BACKGROUND

Insulin-resistant individuals are known to have dyslipidemia and are predicted to be at high risk of cardiovascular events. Vitamin D deficiency was shown to be associated with dyslipidemia; however, the type of dyslipidemia associated with vitamin D deficiency in insulin-resistant individuals is not determined. Furthermore, there is evidence linking insulin resistance with low-grade inflammation suggesting levels of pro-inflammatory cytokines to be increased in insulin-resistant states.

OBJECTIVE

This study was performed to evaluate the impact of vitamin D deficiency, defined as serum level of 25(OH)D below 20 ng/mL, on lipid profile and inflammatory markers such as interleukin (IL-6) and IL-8, as well as soluble thrombomodulin (TM) in the serum of insulin-resistant individuals.

METHODS

A total of 4114 individuals had simultaneous serum 25(OH)D, insulin, and lipid panel testing during 2013 as part of the United Arab Emirates National Diabetes and Lifestyle (UAEDIAB) study. Multivariate logistic regression analysis was used to assess the association between serum level of 25(OH)D and lipid profile in insulin-sensitive versus -resistant individuals. The lipid panel was stratified into high total cholesterol (TC: >6.2 mmol/L), high low-density lipoprotein-cholesterol (LDL-C: >2.59 mmol/L), high triglycerides (TG: >2.3 mmol/L), and low high-density lipoprotein-cholesterol (HDL-C: <1.55 mmol/L) dyslipidemia. Furthermore, the immunomodulatory and vasculoprotective effects of 25(OH)D were assessed by measuring the levels of IL-6, IL-8, and soluble TM in serum using ELISA.

RESULTS

More than half of the 4114 individuals were insulin resistant (n=2760, 67%) and around one-fifth of them were vitamin D-deficient (n=796, 19%). After adjusting for age, gender, body mass index, smoking, ethnicity, and educational level, the only dyslipidemia associated with vitamin D-deficient-insulin-resistant individuals (OR 2.09 [95]; P=0.009) was lower HDL-C. Furthermore, deficient 25(OH)D individuals with low HDL-C levels had higher circulatory IL-6 and IL-8 levels, and higher serum soluble TM compared to individuals with sufficient 25(OH)D and normal lipid profiles (median, IL-6 pg/mL 0.82 vs 1.71, P=0.001; median, IL-8 pg/mL 51.31 vs 145.6, P=0.003; and median, soluble TM ng/mL 5.19 vs 7.38, P<0.0001; in sufficient vs deficient groups, respectively).

CONCLUSION

The results of our study showed that in insulin-resistant individuals, vitamin D deficiency status is associated with HDL-C dyslipidemia and higher serum inflammatory and endothelial damage markers.

Thrombospondin-1 and Vitamin D in Children With Sickle Cell Anemia

BACKGROUND

Thrombospondin-1 (TSP-1) and 25-hydroxyvitamin D (25-OHD) play significant roles in the pathogenesis of sickle cell anemia (SCA). TSP-1 enhances cellular adhesion/inflammation, hence contributing to vaso-occlusive crisis (VOC); vitamin D, in contrast, retards inflammation and may lower rate of pain episodes. We determined serum levels of TSP-1 and 25-OHD in Nigerian children with SCA and their matched hemoglobin AA controls; and assess the relationship between the 2 biomarkers.

METHODS

In total 90 children (32 SCA in steady state, 30 SCA in VOC, and 28 HbAA controls) were studied. Serum TSP-1 and 25-OHD levels were measured with ELISA and HPLC, respectively.

RESULTS

The mean TSP-1 of children with VOC was significantly higher than those in steady state (P=0.022) and HbAA controls (P<0.001). Similarly, the mean TSP-1 of those in steady state was higher than the controls (P=0.007). However, mean serum 25-OHD of the children with VOC was significantly lower than those in steady state (28.9±8.2 ng/mL vs. 37.1±12.3 ng/mL, P =0.004). There was a significant inverse correlation between TSP-1 and 25-OHD among the VOC subgroup, r=-0.57, P=0.001. The mean TSP-1 of the 28 children with SCA who had suboptimal vitamin D (213.5±118.6 ng/mL) was higher than 144.2±58.7 ng/mL of the 34 SCA who had normal serum vitamin D, P=0.008.

CONCLUSIONS

Children with SCA, especially those with VOC, had high serum TSP-1 and low 25-OHD. Also, an inverse relationship exist between serum 25-OHD and TSP-1 in children with VOC. These findings provide basis for further studies into the regulation of TSP-1 by vitamin D.

Sickle cell disease: Hemostatic and inflammatory changes, and their interrelation

Sickle cell disease, the most common genetic blood disorder in the world, has high clinical variability, negatively impacts quality of life and contributes to early mortality. Sickled erythrocytes cause blood flow obstruction, hemolysis, and several hemostatic changes that promote coagulation. These events, in turn, induce chronic inflammation, characterized by elevated plasma levels of pro-inflammatory markers, which aggravates the already unfavorable state of the circulatory system. Empirical evidence indicates that the hemostatic and inflammatory systems continuously interact with each other and thereby further propagate the hypercoagulability and inflammatory conditions. In this review article, we discuss the pathophysiological aspects of sickle cell disease and the hemostatic and inflammatory changes that underlie its pathogenesis.

Measuring success: utility of biomarkers in sickle cell disease clinical trials and care

Progress in the care of sickle cell disease (SCD) has been hampered by the extreme complexity of the SCD phenotype despite its monogenic inheritance. While epidemiological studies have identified clinical biomarkers of disease severity, with a few exceptions, these have not been routinely incorporated in clinical care algorithms. Furthermore, existing biomarkers have been poorly apt at providing objective parameters to diagnose sickle cell crisis, the hallmark, acute complication of SCD. The repercussions of these diagnostic limitations are reflected in suboptimal care and scarcity of adequate outcome measures for clinical research. Recent progress in molecular and imaging diagnostics has heralded a new era of personalized medicine in SCD. Precision medicine strategies are particularly timely, since molecular therapeutics are finally on the horizon. This chapter will summarize the existing evidence and promising data on biomarkers for clinical care and research in SCD.

Acute chest syndrome in sickle cell anaemia: higher serum levels of interleukin-8 and highly sensitive C-reactive proteins are associated with impaired lung function

BACKGROUND

Sickle cell anaemia (SCA) is a chronic inflammatory disorder with multiple organ manifestations including acute and long-term pulmonary dysfunction.

AIMS/OBJECTIVES

To assess lung function of children with SCA and determine the possible role of acute chest syndrome (ACS), serum inflammatory cytokines, highly sensitive C-reactive protein (hs-CRP), leucocytes and 25-hydroxyvitamin D on the development of impaired lung function.

SUBJECTS AND METHODS

Lung function of 76 children with SCA was determined by spirometer and classified into normal or impaired. Sociodemographic, clinical, haematological, biochemical and immunological data of the two groups were compared by univariate and multivariate analyses.

RESULTS

Fifty (65.8%) patients had impaired lung function, comprising of 30.3%, 3.9% and 31.6% with restrictive, obstructive and mixed disease patterns, respectively. Children with previous ACS were 3.6 times more likely to have impaired lung function than those without ACS (82.1% vs 56.3%, p = 0.02, OR 3.6, 95% CI 1.2-10.8). Interleukin (IL)-8 and hs-CRP were significantly higher in patients with impaired lung function (p = 0.02 and <0.001, respectively). Using logistic regression, previous ACS (OR 5.8, 95% CI 1.1-5.8, p = 0.03) and higher serum IL-8 levels (OR 3.0, 95% CI 1.0-8.0, p = 0.02) independently predicted the presence of abnormal lung function.

CONCLUSIONS

Lung dysfunction, predominantly restrictive pattern, is common in SCA and is associated with previous ACS and alterations in immunological markers, especially serum IL-8 and hs-CRP.

ABBREVIATIONS

ACS: acute chest syndrome; CBT: chronic blood transfusion; ELISA: enzyme-linked immunosorbent assay; FEV₁: forced expiratory volume in 1 s; FVC: forced vital capacity; HPLC: high-density liquid chromatography; hs-CRP: highly sensitive C-reactive proteins; HU: hydroxyurea; IL: Interleukin; PEFR: peak expiratory flow rate; SEM: standard error of the mean; TLC: total lung capacity; 25-OHD: 25-hydroxyvitamin D; VOC: vaso-occlusive crisis; WGH: Wesley Guild Hospital.

Vitamin D Deficiency and Its Association with Inflammatory Markers, Lipid Profile and Regulatory T-cells in Pediatric Sickle Cell Disease Patients

We investigated vitamin D deficiency in pediatric sickle cell disease patients and its association with selected bone, lipid and inflammatory parameters. The study included 64 patients (33 SS and 31 SB) and 21 carriers (AS). Blood was obtained to assess levels of vitamin D, WBC, CRP, Ca, P, ALP, PTH, triglyceride, total cholesterol, LDL, VLDL, HDL, IL-2, IL-12, TNF-α, IL-4, IL-6, IL-10 and regulatory T cells. The patients were grouped according to their genotype (SS, SB) and vitamin D status (low or normal). Carriers were also grouped as low or normal vitamin D. Laboratory findings were similar between low and normal Vit D groups in SS, SB and AS genotypes except a lower IL-12 in SB-low vitamin D compared SB-normal vitamin D group. Acute chest syndrome was more frequent in SS-low Vit D (63%) compared to SS-normal Vit D (25%), SB-low Vit D (21%) and SB-normal Vit D (33%) (P = 0.045). Both SS and SB with low vitamin D had higher VLDL (P = 0.006 and P = 0.022), TNF-α (P = 0.001) and regulatory T cells (P = 0.000) compared to AS-low vitamin D. Both SS and SB with normal vitamin D had higher levels of regulatory T cells (P = 0.000) compared to AS-normal vitamin D. Vit D was not a modifier of selected inflammation, bone and lipid parameters in sickle cell disease. Acute chest syndrome was comparably more frequent in SS-low vitamin D. Increase of regulatory T cells in the patients was a result of chronic inflammation in sickle cell disease.