Transient hypertriglyceridemia of infancy

A risk factor for early wheezing in infants: rapid weight gain

Background

The aim of this study was to investigate the correlation between rapid weight gain and early wheezing.

Methods

This study screened 701 infants with lower respiratory tract infection who were no more than 4 months from Jan 1st to Dec 31st in 2018. According to weight-for-age Z-value (WAZ), these infants were divided into the considerably slow weight gain group (group I), the normal weight gain group (group II) and the excessively rapid weight gain group (group III), respectively. The clinical characteristics, weight growth speeds and serum lipid levels were analyzed, and multivariable Logistic model was conducted to select significant variables.

Results

Our results showed that male (OR = 1.841, 95%CI: 1.233–2.751), family wheezing (OR = 5.118, 95%CI: 2.118–12.365), age (OR = 1.273, 95%CI: 1.155–1.403), eczema (OR = 2.769, 95%CI: 1.793–4.275), respiratory syncytial virus (RSV) infection (OR = 1.790, 95%CI: 1.230–2.604), birth weight (OR = 1.746, 95%CI: 1.110–2.746) and total cholesterol (TC) (OR = 1.027, 95%CI: 1.019–1.036) and ΔWAZ (OR = 1.182, 95%CI: 1.022–1.368) were associated with early wheezing. Results indicated that serum TC (P = 0.018) and ΔWAZ (P = 0.023) were positive correlation with wheezing days.

Conclusion

Besides male, family wheezing, age, eczema, RSV infection, birth weight and TC, the rapid weight growth as a risk factor should be concerned in the early wheezing infants.

Lipemia retinalis in an infant treated for retinopathy of prematurity

Lipemia retinalis is an unusual ocular finding associated with hypertriglyceridemia. We report the case of an infant treated for retinopathy of prematurity who later developed lipemia retinalis, with triglyceride levels of 4736 mg/dl. There was a paradoxical worsening of hypertriglyceridemia with the use of medium chain triglyceride supplement. On discontinuing the supplement, the triglycerides level drastically dropped, and retinal vasculature returned to a normal hue.

On transient breastfeeding-related chylomicronaemia syndrome

This paper reports on two male infants with abnormally high levels of serum triacylglycerols (>15.00 mmol/l) and massive accumulation of chylomicrons. Pathological lipidograms were observed during breastfeeding only and were typical of a rare chylomicronaemia syndrome. Laboratory abnormalities were detected accidentally in the otherwise healthy infants. An unrecognized modulating factor in fresh mother's milk caused transitory decreased activity of hydrolytic complex for chylomicrons and very-low-density lipoproteins, probably due to a dysfunction of lipoprotein lipase. The normalization of lipidograms suggested that the catalytic activity of lipoprotein lipase rapidly recovered after weaning. Pathogenesis moved more towards an immune disorder, to the production of (auto)antibodies against a component of the lipolytic system. Mother's milk should be substituted with banked donor human milk, but this is not an unambiguous demand.

CONCLUSION

Fresh mother's milk caused a decrease in the activity of lipolytic enzyme (lipoprotein lipase). The massive hypertriacylglycerolaemia quickly disappeared after weaning. Two infants with this transient chylomicronaemia syndrome were asymptomatic.

New mutations in the lipoprotein lipase gene in a young boy with chylomicronaemia syndrome and in his family

The case is reported of a 4-y-old boy with chylomicronaemia syndrome, under treatment with a low-fat diet and medium-chain triglycerides. The clinical and biochemical characteristics of the patient and 11 members of his family were studied. Lipoprotein profile, lipoprotein lipase (LPL) mass and activity were evaluated. Nucleotide substitutions in LPL promoter and exons were screened. The proband presented with severe hypertriglyceridaemia (triglycerides = 13.25 mmol l(-1)) and non-detectable LPL activity and mass. The boy was a compound heterozygote for four molecular defects in the LPL gene, two of which have not been reported before (CGT764 CTT/Arg170 --> Leu; GGA1482 --> GGT/Gly409 --> Gly). Among the family members, the proband was the only one who carried two genetic variants that modify LPL amino acid composition.

CONCLUSION

The association of different alterations in the LPL gene could be a key factor in causing the severe phenotype observed. Moreover, treatment with a low-fat diet and medium-chain triglycerides failed to normalize the patient's hypertriglyceridaemia.

Two cases with transient lipoprotein lipase (LPL) activity impairment: evidence for the possible involvement of an LPL inhibitor

Two independent severe hypertriglyceridemic infants with transiently impaired lipoprotein lipase (LPL) activity were observed and the causes were explored. Both infants were female, born prematurely with low birth weight and developed hypertriglyceridemia (Fredrickson type V hyperlipidemia: high VLDL and low LDL/HDL) a few months after birth. While mass levels of their post-heparin plasma LPL and apoprotein C-II (apo C-II), a physiological activator of LPL, were normal, their post-heparin plasma LPL activities were remarkably impaired. Both of their mothers' post-heparin plasma LPL activities were slightly or moderately impaired as well, without a decrease in the LPL mass level. No mutations in the genes for LPL and apo C-II were detected in either patient. In an in vitro study with their serum at onset, we could not detect any distinct circulating inhibitors for LPL. There was no data supporting infection or autoimmune diseases, which might have an impact on LPL activity, during the follow-up period. Levels of their plasma triglyceride (TG) and total cholesterol (TC) were decreased quickly by a dietary intervention with medium-chain triglyceride (MCT) milk and kept normal even after stopping the intervention at around age 1 year. However, their low post-heparin LPL activity persisted and returned to normal at around age 2 years. Their low HDL cholesterol levels persisted even after recovery of the TG and TC levels, although lecithin:cholesterol acyltransferase (LCAT) and cholesterol-ester-transfer protein (CETP), two key enzymes of HDL metabolism, were normal throughout the course. The exact reasons why their post-heparin LPL activities were impaired for a certain period and why their HDL cholesterol levels have remained low are still unclear.

CONCLUSION

Transiently impaired LPL activity with no defect in LPL enzyme induced severe hypertriglyceridemia in infants. The transient occurrence of inhibitor(s) for LPL was proposed.