Variants In The Il6 And Il1β Genes Either Alone Or In Combination With C282Y HFE Mutations Modify The Hepatic Iron Phenotype Of Patients With Nonalcoholic Fatty Liver Disease
The goal of this study was to investigate if IL6 and IL1β cytokine SNPs, alone or in combination with HFE gene mutations, can affect the grade and pattern of hepatic iron deposition and serum iron markers in the well characterized NASH CRN cohort.
Similar a Variants In The Il6 And Il1β Genes Either Alone Or In Combination With C282Y HFE Mutations Modify The Hepatic Iron Phenotype Of Patients With Nonalcoholic Fatty Liver Disease
Similar a Variants In The Il6 And Il1β Genes Either Alone Or In Combination With C282Y HFE Mutations Modify The Hepatic Iron Phenotype Of Patients With Nonalcoholic Fatty Liver Disease (12)
Variants In The Il6 And Il1β Genes Either Alone Or In Combination With C282Y HFE Mutations Modify The Hepatic Iron Phenotype Of Patients With Nonalcoholic Fatty Liver Disease
1. Variants In The IL6 And IL1B Genes, Either
Alone, Or In Combination With C282Y HFE
Mutations, Modify The Hepatic Iron
Phenotype Of Patients With NAFLD
JE Nelson, D Kleiner, KV Kowdley, for the
NASH Clinical Research Network
AS040
2. Aim
The goal of this study was to investigate if IL6 and IL1β
cytokine SNPs, alone or in combination with HFE gene
mutations, can affect the grade and/or pattern of
hepatic iron deposition and serum iron markers in the
well characterized NASH CRN cohort.
3. Background
• The iron regulatory hormone hepcidin is
regulated by both iron and inflammatory signals
including IL6 and IL1β cytokines.
• We have previously shown carriage of C282Y
HFE mutations in NAFLD patients is associated
with decreased hepcidin levels and increased
hepatocellular (HC) iron deposition in this
cohort.
4. • Genotyping performed in 787 adult (≥18 yrs) subjects
with biopsy proven NAFLD and hepatic iron staining
results.
• Serum hepcidin levels were determined by ELISA
immunoassay (Intrinsic LifeSciences).
• Stats: ordinal or linear regression adjusting for sex was
used to determine the association of each genotype
with ordinal or continuous variables.
• The effects of HFE mutations and the IL6 and IL1B
SNPs were investigated using regression analysis with
interaction terms.
Methods
5. TABLE 1. Single nucleotide polymorphism details
SNP ID
Common
Name SNP Type
HapMap
-CEU*
RAF
Study
RAF Location Model
rs1800795 IL6 -174G>C
promoter;
MEF site 0.47 0.41
chr. 7
22766645
G allele
recessive
rs10499563 IL6 -6331T>C
promoter;
Oct-1 binding site 0.19 0.21
chr. 7
22760488
C allele
dominant
rs2069849 IL6+4272C>T
coding;
synonymous, exon 5 0.01 0.02
chr. 7
22771156
T allele
dominant
rs1143627 IL1B -31T>C promoter 0.36 0.34
chr. 7
113594387
T allele
dominant
rs16944 IL1B -511C>T promoter 0.36 0.33
chr. 7
113594867
C allele
dominant
rs1143634 IL1B +3954C>T
coding;
synonymous, exon 5 0.21 0.24
chr. 7
113590390
T allele
recessive
RAF=Rare Allele Frequency in white, non-hispanics
*Utah residents with Northern and Western European ancestry from the CEPH collection
6. FIGURE 1. Effect of IL1B genotypes on HC iron stain grade
Values are mean ± SEM; p values from ordinal regression adjusting for sex
7. FIGURE 2. Effect of IL1B genotypes on hepcidin levels
Values are mean ± SD; p values from linear regression adjusting for sex
8.
9.
10. Conclusions
• The IL1B rs16944, rs1143627 and rs1143634 SNPs
impact iron regulation in NAFLD subjects.
• The IL6 -6331T>C loci modifies the effect of HFE C282Y
mutations upon iron regulation in NAFLD subjects,
possibly through a positive effect by IL6.
• In all genotypes there was a positive association
between serum hepcidin levels and markers of iron,
including iron stain grade suggesting serum hepcidin
levels in patients with NAFLD reflect the physiologic
response to body iron stores.
