Genetic and environmental determinants of variation of soluble adhesion molecules

Evaluation of Endothelial Cell Adhesion Molecules and Anti-C1q Antibody in Discriminating between Active and Non-Active Systemic Lupus Erythematosus

BACKGROUND

Detecting the active state of systemic lupus erythematosus (SLE) is important but challenging. This study aimed to determine the diagnostic accuracy of serum endothelial cell adhesion molecules (ICAM-1 and VCAM-1) and anti-C1q antibody in discriminating between active and non-active SLE.

METHODS

Using SELENA-SLE disease activity index (SLEDAI), 95 SLE patients (45 active and 50 non-active) were assessed. A score above five was considered indicative of active SLE. The blood samples were tested for serum ICAM-1, VCAM-1 and anti-C1q antibody using enzyme-linked immunosorbent assay (ELISA).

RESULTS

The levels of serum VCAM-1 and anti-C1q antibody were significantly higher in active SLE patients. Both VCAM-1 and anti-C1q were able to discriminate between active and non-active SLE (p-value < 0.001 and 0.005, respectively). From the receiver operating characteristic curves (ROCs) constructed, the optimal cut-off values for VCAM-1 and anti-C1q antibody in discriminating between active and non-active SLE were 30.5 ng/mL (69.0% sensitivity, 60.0% specificity, PPV 58.5%, NPV 66.7%) and 7.86 U/mL (75.6% sensitivity, 80% specificity, PPV 77.3%, NPV 78.4%), respectively. However, serum ICAM-1 level was unable to discriminate between the two groups (p-value = 0.193).

CONCLUSION

Anti-C1q antibody demonstrated the best diagnostic accuracy in discriminating between active and non-active SLE patients.

Contribution of body composition components and soft-tissue biochemical factors to genetic variation of body mass index (BMI) in an ethnically homogeneous population

OBJECTIVES

Elevated BMI results from an excess of not only fat mass (FM) but also fat-free soft tissue mass (FFM). Both components of body soft tissue, FM, and FFM, are now considered as active endocrine organs. The major aim of this study was to explore the genetic architecture of BMI, considering genetic variations of its major soft tissue components, and the main biochemical factors associated with their corresponding metabolism: leptin, adiponectin, E-selectin, and insulin-like growth factor binding protein, IGFBP-1.

METHODS

A total of 1,502 apparently healthy individuals (783 men, 719 women) from 359 ethnically homogeneous families were assessed anthropometrically for body composition. Model-based quantitative genetic analyses were implemented to reveal genetic and shared environmental factors affecting the variation and covariation of the studied phenotypes.

RESULTS

We found that inter-individual variation in BMI is strongly correlated with both body composition components (r > 0.92, P < 0.001). These correlations are caused by shared genetic and environmental factors that were interpreted to be a direct result of the intimate genetic and environmental correlations between FM and FFM. The latter were also significantly correlated with leptin, E-selectin, and IGFBP-1. However, whereas leptin displayed both genetic and environmental correlations with both FM and FFM, their correlations with E-selectin were caused only by common genes, and with IGFBP-1-only by a shared environment.

CONCLUSIONS

This study clearly suggests that FM and FFM contributed almost equally to BMI variation, and provides evidence that this contribution is caused by common genetic as well as shared environmental and metabolic factors.

Association of variation at the ABO locus with circulating levels of soluble intercellular adhesion molecule-1, soluble P-selectin, and soluble E-selectin: a meta-analysis

BACKGROUND

Circulating levels of soluble intercellular adhesion molecule-1, soluble P-selectin, and soluble E-selectin have been associated with variation at the ABO locus. To evaluate these associations and the effect sizes, we performed a meta-analysis with new and previous reported data for polymorphism rs579459.

METHODS AND RESULTS

Compared with major allele homozygotes, heterozygotes and minor allele homozygotes had 4.6% (95% CI, 3.4%-5.8%, P=7.3 × 10(-14)) and 7.2% (95% CI, 4.7%-9.7%, P=1.5 × 10(-8)), respectively, lower soluble intercellular adhesion molecule-1 levels (n=33 671). An allele dose-dependent association also was observed for soluble P-selectin (n=4921) with heterozygotes and minor allele homozygotes having 11.5% (95% CI, 7.2%-15.8%, P=1.7 × 10(-7)) and 18.6% (95% CI, 9.1%-28.1%, P=1.2 × 10(-4)), respectively, lower levels than in major allele homozygotes. A larger effect size, again consistent with an additive genetic model, was seen for soluble E-selectin (n=2860) whose level was 25.6% (95% CI, 19.0%-32.2%, P=2.1 × 10(-14)) lower in heterozygotes and 43.3% (95% CI, 36.9%-49.3%, P=4.3 × 10(-42)) lower in minor allele homozygotes than in major allele homozygotes.

CONCLUSIONS

The data support the association of variation at the ABO locus with soluble intercellular adhesion molecule-1, soluble P-selectin, and soluble E-selectin levels.

Genome-wide association identifies the ABO blood group as a major locus associated with serum levels of soluble E-selectin

BACKGROUND

Elevated serum soluble E-selectin levels have been associated with a number of diseases. Although E-selectin levels are heritable, little is known about the specific genetic factors involved. E-selectin levels have been associated with the ABO blood group phenotype.

METHODS AND RESULTS

We performed a high-resolution genome-wide association study of serum soluble E-selectin levels in 685 white individuals with type 1 diabetes from the Diabetes Control and Complications Trial (DCCT)/Epidemiology of Diabetes Intervention and Complications (EDIC) study to identify major loci influencing levels. Highly significant evidence for association (P=10(-29)) was observed for rs579459 near the ABO blood group gene, accounting for 19% of the variance in E-selectin levels. Levels of E-selectin were higher in O/O than O/A heterozygotes, which were likewise higher than A/A genotypes. Analysis of subgroups of A alleles reveals heterogeneity in the association, and even after this was accounted for, an intron 1 SNP remained significantly associated. We replicate the ABO association in nondiabetic individuals.

CONCLUSIONS

ABO is a major locus for serum soluble E-selectin levels. We excluded population stratification, fine-mapped the association to sub-A alleles, and also document association with additional variation in the ABO region.