Atsuko Takagi

Triglyceride deposit cardiomyovasculopathy (TGCV) is a phenotype primarily reported in patients carrying genetic mutations in PNPLA2 encoding adipose triglyceride lipase (ATGL) which releases long chain fatty acid (LCFA) as a major energy source by the intracellular TG hydrolysis. These patients suffered from intractable heart failure requiring cardiac transplantation. Moreover, we identified TGCV patients without PNPLA2 mutations based on pathological and clinical studies. We provided the diagnostic criteria, in which TGCV with and without PNPLA2 mutations were designated as primary TGCV (P-TGCV) and idiopathic TGCV (I-TGCV), respectively. We hereby report clinical profiles of TGCV patients. Between 2014 and 2018, 7 P-TGCV and 18 I-TGCV Japanese patients have been registered in the International Registry. Patients with I-TGCV, of which etiologies and causes are not known yet, suffered from adult-onset severe heart disease, including heart failure and coronary artery disease, associated with a marked reduction in ATGL activity and myocardial washout rate of LCFA tracer, as similar to those with P-TGCV. The present first registry-based study showed that TGCV is an intractable, at least at the moment, and heterogeneous cardiovascular disorder.

We report a case of non-alcoholic steatohepatitis complicated with acute pancreatitis induced by hypertriglyceridemia in a young Japanese woman. A precise examination of the lipid profile showed decreased lipoprotein lipase (LPL) and hepatic triglyceride lipase activity levels, while the LPL mass was at the minimum level of the normal range.

Human LPL is a glycoprotein enzyme with a molecular mass of 61 kDa, and it plays a key role in regulating the triglyceride (TG) levels in circulation by hydrolyzing TGs in TG-rich lipoproteins at the first step in their metabolism. Homozygous or compound heterozygous LPL deficiency causes severe fasting hypertriglyceridemia. Heterozygous LPL deficiency usually results in a normolipidemic state, but this may cause mild hypertriglyceridemia if heterozygotes are exposed to factors, such as high alcohol intake and/or a hyperinsulinemic state. Severe fasting hypertriglyceridemia is mainly caused by abnormalities of the LPL gene, whereas there are some cases caused by gene defects relating to synthesis and transport of LPL such as LMF and GPIHBP1, and by an autoantibody to LPL acting as inhibitor of LPL.