Transitional Medicine of Intractable Primary Dyslipidemias in Japan.

Transitional medicine refers to the seamless continuity of medical care for patients with childhood-onset diseases as they grow into adulthood. The transition of care must be seamless in medical treatment as the patients grow and in other medical aids such as subsidies for medical expenses in the health care system. Inappropriate transitional care, either medical or social, directly causes poorer prognosis for many early-onset diseases, including primary dyslipidemia caused by genetic abnormalities. Many primary dyslipidemias are designated as intractable diseases in the Japanese health care system for specific medical aids, as having no curative treatment and requiring enormous treatment costs for lipid management and prevention of complications. However, there are problems in transitional medicine for primary dyslipidemia in Japan. As for the medical treatment system, the diagnosis rate remains low due to the shortage of specialists, their insufficient link with generalists and other field specialists, and poor linkage between pediatricians and physicians for adults. In the medical care system, there is a mismatch of diagnostic criteria of primary dyslipidemias between children and adults for medical care expense subsidization, as between The Program for the Specific Pediatric Chronic Diseases and the Program for Designated Adult Intractable Diseases. This could lead some patients subsidized in their childhood to no longer be under the coverage of the aids after transition. This review intends to describe these issues in transitional medicine of primary dyslipidemia in Japan as a part of the efforts to resolve the problems by the Committee on Primary Dyslipidemia under the Research Program on Rare and Intractable Disease of the Ministry of Health, Labour and Welfare of Japan.

Guidelines for the Diagnosis and Treatment of Pediatric Familial Hypercholesterolemia 2022.

As atherosclerosis begins in childhood, early diagnosis and treatment of familial hypercholesterolemia (FH) is considered necessary. The basic diagnosis of pediatric FH (under 15 years of age) is based on hyper-low-density lipoprotein (LDL) cholesterolemia and a family history of FH; however, in this guideline, to reduce overlooked cases, "probable FH" was established. Once diagnosed with FH or probable FH, efforts should be made to promptly provide lifestyle guidance, including diet. It is also important to conduct an intrafamilial survey, to identify family members with the same condition. If the level of LDL-C remains above 180 mg/dL, drug therapy should be considered at the age of 10. The first-line drug should be statin. Evaluation of atherosclerosis should be started using non-invasive techniques, such as ultrasound. The management target level is an LDL-C level of less than 140 mg/dL. If a homozygous FH is suspected, consult a specialist and determine the response to pharmacotherapy with evaluating atherosclerosis. If the response is inadequate, initiate lipoprotein apheresis as soon as possible.

Universal Screening for Familial Hypercholesterolemia in Children in Kagawa, Japan.

AIM: Familial hypercholesterolemia (FH) is an underdiagnosed autosomal dominant genetic disorder characterized by high levels of plasma low-density lipoprotein cholesterol (LDL-C) from birth. This study aimed to assess the genetic identification of FH in children with high LDL-C levels who are identified in a universal pediatric FH screening in Kagawa, Japan. METHOD: In 2018 and 2019, 15,665 children aged 9 or 10 years underwent the universal lipid screening as part of the annual health checkups for the prevention of lifestyle-related diseases in the Kagawa prefecture. After excluding secondary hyper-LDL cholesterolemia at the local medical institutions, 67 children with LDL-C levels of ≥ 140 mg/dL underwent genetic testing to detect FH causative mutations at four designated hospitals. RESULTS: The LDL-C levels of 140 and 180 mg/dL in 15,665 children corresponded to the 96.3 and 99.7 percentile values, respectively. Among 67 children who underwent genetic testing, 41 had FH causative mutations (36 in the LDL-receptor, 4 in proprotein convertase subtilisin/kexin type 9, and 1 in apolipoprotein B). The area under the curve of receiver operating characteristic curve predicting the presence of FH causative mutation by LDL-C level was 0.705, and FH causative mutations were found in all children with LDL-C levels of ≥ 250 mg/dL. CONCLUSION: FH causative mutations were confirmed in almost 60% of the referred children, who were identified through the combination of the lipid universal screening as a part of the health checkup system and the exclusion of secondary hyper-LDL cholesterolemia at the local medical institutions.

Genetic Analysis of Japanese Children Clinically Diagnosed with Familial Hypercholesterolemia.

AIM: This study aimed to elucidate the gene and lipid profiles of children clinically diagnosed with familial hypercholesterolemia (FH). METHODS: A total of 21 dyslipidemia-related Mendelian genes, including FH causative genes (LDLR, APOB, and PCSK9) and LDL-altering genes (APOE, LDLRAP1, and ABCG5/8), were sequenced in 33 Japanese children (mean age, 9.7±4.2 years) with FH from 29 families. RESULTS: Fifteen children (45.5%) with pathogenic variants in LDLR (eight different heterozygous variants) and one child (3.0%) with the PCSK9 variant were found. Among 17 patients without FH causative gene variants, 3 children had variants in LDL-altering genes, an APOE variant and two ABCG8 variants. The mean serum total cholesterol (280 vs 246 mg/dL), LDL-cholesterol (LDL-C, 217 vs 177 mg/dL), and non-HDL cholesterol (228 vs 188 mg/dL) levels were significantly higher in the pathogenic variant-positive group than in the variant-negative group. In the variant-positive group, 81.3% of patients had LDL-C levels ≥ 180 mg/dL but 35.3% in the variant-negative group. The mean LDL-C level was significantly lower in children with missense variants, especially with the p.Leu568Val variant, than in children with other variants in LDLR, whereas the LDL-altering variants had similar effects on the increase in serum LDL-C to LDLR p.Leu568Val. CONCLUSION: Approximately half of the children clinically diagnosed with FH had pathogenic variants in FH causative genes. The serum LDL-C levels tend to be high in FH children with pathogenic variations, and the levels are by the types of variants. Genetic analysis is useful; however, further study on FH without any variants is required.

Distribution of serum adiponectin isoforms in pediatric patients with steroid-sensitive nephrotic syndrome.

BACKGROUND: Serum adiponectin circulates in three multimeric isoforms: high-molecular-weight (HMW), middle-molecular-weight (MMW), and low-molecular-weight (LMW) isoforms. Potential change in the circulating adiponectin levels in patients with nephrotic syndrome (NS) remain unknown. This study aimed to assess the levels of total adiponectin and the distribution of its isoforms in pediatric patients with NS. METHODS: We sequentially measured total adiponectin and each adiponectin isoform levels at the onset of NS, initial remission, and during the remission period of the disease in 31 NS patients. We also calculated the ratios of HMW (%HMW), MMW (%MMW), and LMW (%LMW) to total adiponectin incuding 51 control subjects. RESULTS: The median of total serum adiponectin levels in patients were 36.7, 36.7, and 20.2 µg/mL at the onset, at initial remission, and during the remission period of NS, respectively. These values were significantly higher than those in control subjects. The median values of %HMW, %MMW, and %LMW values were 56.9/27.0/14.1 at the onset, 62.0/21.8/13.4 at the initial remission, and 58.1/21.7/17.5 at during the remission period of NS, respectively. Compared with control subjects, %HMW at initial remission and %MMW at the onset were high, and the %LMW values at the onset and at initial remission were low. CONCLUSIONS: In patients with NS, total serum adiponectin levels increase at the onset of the disease, and the ratio of adiponectin isoforms changes during the course of the disease. Further studies are needed to delineate the mechanisms between proteinuria and adiponectin isoforms change.

Homozygous Familial Hypercholesterolemia.

Familial hypercholesterolemia (FH) is an inherited disorder with retarded clearance of plasma LDL caused by mutations of the genes involved in the LDL receptor-mediated pathway and most of them exhibit autosomal dominant inheritance. Homozygotes of FH (HoFH) may have plasma LDL-C levels, which are at least twice as high as those of heterozygous FH (HeFH) and therefore four times higher than normal levels. Prevalence of HoFH had been estimated as 1 in 1,000,000 before but more recent genetic analysis surveys predict 1 in 170,000 to 300,000. Since LDL receptor activity is severely impaired, HoFH patients do not or very poorly respond to medications to enhance activity, such as statins, and have a poorer prognosis compared to HeFH. HoFH should therefore be clinically distinguished from HeFH. Thorough family studies and genetic analysis are recommended for their accurate diagnosis.Fatal cardiovascular complications could develop even in the first decade of life for HoFH, so aggressive lipid-lowering therapy should be initiated as early as possible. Direct removal of plasma LDL by lipoprotein apheresis has been the principal measure for these patients. However, this treatment alone may not achieve stable LDL-C target levels and combination with drugs should be considered. The lipid-lowering effects of statins and PCSK9 inhibitors substantially vary depending on the remaining LDL receptor activity of individual patients. On the other hand, the action an MTP inhibitor is independent of LDL receptor activity, and it is effective in most HoFH cases.This review summarizes the key clinical issues of HoFH as well as insurance coverage available under the Japanese public healthcare system.

Diagnosis and Management of Sitosterolemia 2021.

Sitosterolemia is an inherited metabolic disorder characterized by increased levels of plant sterols, such as sitosterol. This disease is caused by loss-of-function genetic mutations in ATP-binding cassette (ABC) subfamily G member 5 or member 8 (ABCG5 or ABCG8, respectively), both of which play important roles in selective excretion of plant sterols from the liver and intestine, leading to failure to prevent absorption of food plant sterols. This disorder has been considered to be extremely rare. However, accumulated clinical data as well as genetics suggest the possibility of a much higher prevalence. Its clinical manifestations resemble those observed in patients with familial hypercholesterolemia (FH), including tendon xanthomas, hyper LDL-cholesterolemia, and premature coronary atherosclerosis. We provide an overview of this recessive genetic disease, diagnostic as well as therapeutic tips, and the latest diagnostic criteria in Japan.

Guidelines for Diagnosis and Treatment of Familial Hypercholesterolemia 2017.

Statement1. Familial hypercholesterolemia (FH) is an autosomal hereditary disease with the 3 major clinical features of hyper-LDL-cholesterolemia, premature coronary artery disease and tendon and skin xanthomas. As there is a considerably high risk of coronary artery disease (CAD), in addition to early diagnosis and intensive treatment, family screening (cascade screening) is required (Recommendation level A) 2. For a diagnosis of FH, at least 2 of the following criteria should be satisfied:① LDL-C ≥180 mg/dL, ② Tendon/skin xanthomas, ③ History of FH or premature CAD within 2nd degree blood relatives (Recommendation level A) 3. Intensive lipid-lowering therapy is necessary for the treatment of FH. First-line drug should be statins. (Recommendation level A, Evidence level 3) 4. Screening for CAD as well as asymptomatic atherosclerosis should be conducted periodically in FH patients. (Recommendation level A) 5. For homozygous FH, consider LDL apheresis and treatment with PCSK9 inhibitors or MTP inhibitors. (Recommendation level A) 6. For severe forms of heterozygous FH who have resistant to drug therapy, consider PCSK9 inhibitors and LDL apheresis. (Recommendation level A) 7. Refer FH homozygotes as well as heterozygotes who are resistant to drug therapy, who are children or are pregnant or have the desire to bear children to a specialist. (Recommendation level A).

Guidance for Pediatric Familial Hypercholesterolemia 2017.

This paper describes consensus statement by Joint Working Group by Japan Pediatric Society and Japan Atherosclerosis Society for Making Guidance of Pediatric Familial Hypercholesterolemia (FH) in order to improve prognosis of FH.FH is a common genetic disease caused by mutations in genes related to low density lipoprotein (LDL) receptor pathway. Because patients with FH have high LDL cholesterol (LDL-C) levels from the birth, atherosclerosis begins and develops during childhood which determines the prognosis. Therefore, in order to reduce their lifetime risk for cardiovascular disease, patients with FH need to be diagnosed as early as possible and appropriate treatment should be started.Diagnosis of pediatric heterozygous FH patients is made by LDL-C ≥140 mg/dL, and family history of FH or premature CAD. When the diagnosis is made, they need to improve their lifestyle including diet and exercise which sometimes are not enough to reduce LDL-C levels. For pediatric FH aged ≥10 years, pharmacotherapy needs to be considered if the LDL-C level is persistently above 180 mg/dL. Statins are the first line drugs starting from the lowest dose and are increased if necessary. The target LDL-C level should ideally be ＜140 mg/dL. Assessment of atherosclerosis is mainly performed by noninvasive methods such as ultrasound.For homozygous FH patients, the diagnosis is made by existence of skin xanthomas or tendon xanthomas from infancy, and untreated LDL-C levels are approximately twice those of heterozygous FH parents. The responsiveness to pharmacotherapy should be ascertained promptly and if the effect of treatment is not enough, LDL apheresis needs to be immediately initiated.

A novel de novo germline mutation Glu40Lys in AKT3 causes megalencephaly with growth hormone deficiency.

Germline or somatic gain-of-function mutations in the v-akt murine thymoma viral oncogene homolog 3 (AKT3) have been reported to cause syndromic megalencephaly. We describe a novel germline mutation, p.Glu40Lys, in AKT3. Phenotypically, the patient presented with megalencephaly with hypotonia, apparent connective tissue laxity, and growth hormone (GH) deficiency. To our knowledge, this is the first instance of a patient with megalencephaly with GH deficiency, harboring a germline de novo mutation in AKT3. © 2017 Wiley Periodicals, Inc.

Evaluation of Hip/HeightP Ratio as an Index for Adiposity and Metabolic Complications in Obese Children: Comparison with Waist-related Indices.

AIM: To investigate whether body adiposity index (BAI; hip/height1.5-18), pediatric BAI (BAIp; hip/height0.8 - 38), and other hip/heightP ratios are useful in obese children. METHOD: Ninety obese Japanese children, 55 boys and 35 girls, who visited our University Clinic, were enrolled. The age was 9.92±2.6 (mean±SD) years, and the percentage overweight (POW) was 51.6±18.8%. We set the power value of the hip/heightP 0, 0.5, 0.8, 1, 1.5, and 2 and studied the association with overweight indices, biochemical data, and fat area measured by computed tomography. Waist, waist/height ratio, and waist/hip ratio were also evaluated. RESULTS: Hip/height and hip/height0.8 (BAIp) were more closely correlated with POW, body mass index percentile, and percentage body fat than hip/height1.5 (BAI). The correlation coefficient of hip/height with POW (r =0.855) was the highest among the studied hip/heightP indices. The approximate line to predict POW was 411×hip/height-207. The waist/height was also highly correlated with POW (r=0.879). Hip and hip/height0.5 were more closely correlated with visceral fat area than hip/height, BAIp, and hip/height1.5. Hip and hip/height0.5 were significantly correlated with insulin. Only hip was also significantly associated with dyslipidemia. All hip/heightP indices were not significantly correlated with alanine aminotransferase (ALT). Waist was significantly correlated with serum lipids, ALT, and insulin. CONCLUSION: Hip/height and BAIp are better markers for overweight (adiposity) in obese children than BAI. However, hip/height, BAIp, and BAI are not useful to predict metabolic complications. Waist appears to be the best index for obese children overall at this time.

AICAR Attenuates TNFα-Induced Inappropriate Secretion of Monocyte Chemoattractant Protein-1 and Adiponectin in 3T3-L1 Adipocytes.

AIM: The increase in monocyte chemoattractant protein-1 (MCP-1) and the decrease in adiponectin production from hypertrophic adipocytes are associated with adipose tissue inflammation and its metabolic complications. The aim of this study was to determine whether 5-aminoimidazole-4-carboxamide 1-ß-D-ribofuranoside (AICAR), an adenosine monophosphate-activated protein kinase (AMPK) activator, modulates these adipocytokine productions in tumor necrosis factor-α (TNFα)-treated adipocytes. METHODS: AICAR and/or other reagents were added to the culture medium, and then, TNFα was added to fully differentiated 3T3-L1 adipocytes. The MCP-1 and adiponectin production in the culture supernatant was measured by ELISA. AMPK, phosphatidylinositol 3-kinase (PI3K), and nuclear factor-κB (NF-κB) activities were also assayed. RESULTS: Treatment with TNFα increased MCP-1 and decreased adiponectin secretion dose-dependently in the 3T3-L1 adipocytes, and AICAR significantly inhibited these TNFα-mediated changes. Interestingly, metformin, another AMPK activator, did not have such effects on these adipocytokines. Both the AMPK and PI3K systems in the cells were significantly activated by the AICAR treatment, but the effects of AICAR on adipocytokines were not weakened by the addition of dorsomorphin, an AMPK inhibitor, or LY294002, a PI3K inhibitor. Pyrrolidine dithiocarbamate (PDTC), an NF-κB inhibitor, showed protective effects similar to those as AICAR. AICAR, but not metformin, significantly inhibited the TNFα-stimulated activation of NF-κB, and dorsomorphin did not change AICAR's effect. CONCLUSION: AICAR attenuates the TNFα-induced secretion of MCP-1 and adiponectin in 3T3-L1 adipocytes. The observed effects of AICAR seem to be mainly due to the inhibition of NF-κB activation rather than the activation of the AMPK pathway, at least in TNFα-treated adipocytes.