Interleukin-6 blockade raises LDL via reduced catabolism rather than via increased synthesis: a cytokine-specific mechanism for cholesterol changes in rheumatoid …
J Robertson, D Porter, N Sattar, CJ Packard… - Annals of the …, 2017 - ard.bmj.com
J Robertson, D Porter, N Sattar, CJ Packard, M Caslake, I McInnes, D McCarey
Annals of the rheumatic diseases, 2017•ard.bmj.comObjectives Patients with rheumatoid arthritis (RA) have reduced serum low-density
lipoprotein cholesterol (LDL-c), which increases following therapeutic IL-6 blockade. We
aimed to define the metabolic pathways underlying these lipid changes. Methods In the
KALIBRA study, lipoprotein kinetic studies were performed on 11 patients with severe active
RA at baseline and following three intravenous infusions of the IL-6R blocker tocilizumab.
The primary outcome measure was the fractional catabolic rate (FCR) of LDL. Results …
lipoprotein cholesterol (LDL-c), which increases following therapeutic IL-6 blockade. We
aimed to define the metabolic pathways underlying these lipid changes. Methods In the
KALIBRA study, lipoprotein kinetic studies were performed on 11 patients with severe active
RA at baseline and following three intravenous infusions of the IL-6R blocker tocilizumab.
The primary outcome measure was the fractional catabolic rate (FCR) of LDL. Results …
Objectives
Patients with rheumatoid arthritis (RA) have reduced serum low-density lipoprotein cholesterol (LDL-c), which increases following therapeutic IL-6 blockade. We aimed to define the metabolic pathways underlying these lipid changes.
Methods
In the KALIBRA study, lipoprotein kinetic studies were performed on 11 patients with severe active RA at baseline and following three intravenous infusions of the IL-6R blocker tocilizumab. The primary outcome measure was the fractional catabolic rate (FCR) of LDL.
Results
Serum total cholesterol (4.8 vs 5.7 mmol/L, p=0.003), LDL-c (2.9 vs 3.4 mmol/L, p=0.014) and high-density lipoprotein cholesterol (1.23 vs 1.52 mmol/L, p=0.006) increased following tocilizumab therapy. The LDL FCR fell from a state of hypercatabolism to a value approximating that of the normal population (0.53 vs 0.27 pools/day, p=0.006). Changes in FCR correlated tightly with changes in serum LDL-c and C-reactive protein but not Clinical Disease Activity Index.
Conclusions
Patients with RA have low serum LDL-c due to hypercatabolism of LDL particles. IL-6 blockade normalises this catabolism in a manner associating with the acute phase response (and thus hepatic IL-6 signalling) but not with RA disease activity as measured clinically. We demonstrate that IL-6 is one of the key drivers of inflammation-driven dyslipidaemia.
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