Genotypic and phenotypic features in homozygous familial hypercholesterolemia caused by proprotein convertase subtilisin/kexin type 9 (PCSK9) gain-of-function mutation.

BACKGROUNDS: Familial hypercholesterolemia (FH) is an autosomal dominant disease characterized by hypercholesterolemia, tendon xanthomas, and premature coronary heart disease. FH is caused by mutations of "FH genes," which include the LDL-receptor (LDLR), apolipoprotein B-100 (APOB) or proprotein convertase subtilisin/kexin type 9 (PCSK9). We evaluated the usefulness of FH gene analysis for diagnosing homozygous FH (homo-FH), particularly in cases caused by gain-of-function (g-o-f) mutations in PCSK9 (PCSK9 E32K). OBJECTIVES: To evaluate the frequency of homo-FH caused by PCSK9 E32K compared with FH due to other genetic causes and to report the phenotypic features of homo-FH caused by PCSK9 E32K. METHODS: Genomic DNA was prepared from white blood cells, and LDLR and PCSK9 mutations were identified using the Invader assay method. RESULTS: Of the 1055 hetero-FH patients, 62 patients (5.9%) carried the PCSK9 E32K mutation, while in the 82 alleles of 41 homo-FH patients, 13 (15.9%) had double mutations of LDLR allele and PCSK9 E32K mutation. Mean plasma total cholesterol (TC) (9.93 ± 2.95 mmol/L, mean ± SD) in true homo-FH cases with PCSK9 E32K or double hetero-FH cases with PCSK9 E32K and LDLR mutations were significantly lower than those in true homo-FH (18.06 ± 4.96 mmol/L) and compound heterozygous cases with LDLR mutations (14.84 ± 1.62 mmol/L). Mean plasma TC concentrations in the 59 hetero-FH cases with PCSK9 E32K (7.21 ± 1.55 mmol/L) were significantly lower than those (8.94 ± 1.53 mmol/L) in the hetero-FH by LDLR mutations. CONCLUSIONS: FH caused by PCSK9 g-o-f mutations is relatively common in Japan and causes a mild type of homo- and hetero-FH compared with FH caused by LDLR mutations.

Impact of severe earthquake on the occurrence of acute coronary syndrome and stroke in a rural area of Japan.

BACKGROUND: Although acute coronary syndrome (ACS) and stroke are known to increase after earthquake, few data exist regarding the effect of earthquake on these cardiovascular events in rural areas. METHODS AND RESULTS: The Noto Peninsula earthquake with a magnitude of 6.9 occurred at 9:45 a.m. on 25 March 2007. The first case of ACS occurred approximately 15 min later, whereas cerebral hemorrhage (CH) occurred 72 h after the onset of earthquake. During the 35 days after earthquake, among 49 patients who were attended by local ambulance, 5 patients with ACS (10.2%) and 8 with CH (16.3%) were documented and 4 died. The total number of both ACS and CH cases was greater than the averages for the same period of the past 3 years in this area (2.0 vs 5 and 2.3 vs 8, P<0.01). Interestingly, the most cases of ACS had occurred within 7 days after earthquake and for CH not until 35 days later. CONCLUSIONS: Even in rural areas a severe earthquake results in increased incidence of ACS and CH, which can occur at different times after the event, although the effects of other environmental factors should be further investigated.

Risk evaluation of coronary heart disease and cerebrovascular disease by the Japan Atherosclerosis Society Guidelines 2002 using the cohort of the Holicos-PAT study.

Our purpose in this study was to evaluate the new JAS guidelines as a risk assessment tool in Japanese patients with hypercholesterolemia, using the cohort of the Holicos-PAT study. The Holicos-PAT study was designed as a prospective observational study. 2039 patients were followed with or without pravastatin for 5 years. We assessed coronary heart disease (CHD) and cerebrovascular disease (CVD) risks by the patient categories described in the JAS guidelines. In the Holicos-PAT study, the primary endpoints were CHD, and the secondary endpoints were CVD and total mortality. CHD event includes onset and worsening of angina pectoris, performing CABG or PTCA, non-fatal and fatal myocardial infarction, and death from CHD including heart death and sudden death. CVD events are onset or recurrence of cerebral infarction, onset of cerebral hemorrhage, and death from cerebral infarction or hemorrhage. The event rates were calculated by the person-years method, and the differences in event rates between category groups were analyzed by chi-square test. The event rates of CHD in Category A, B1, B2, B3, B4 and C, were 1.1, 4.0, 2.8, 5.7, 18.2 and 38.8 per 1,000 person-years. The rates of CHD events in the higher risk category groups, Category B4 group (p = 0.004 in whole patients) and C group (p < 0.001 in whole patients), were significantly higher than that in the combined category groups A + B1 + B2. The event rates of CVD in Category A, B1, B2, B3, B4 and C, were 2.1, 1.8, 1.8, 0.6, 10.8 and 6.4 per 1,000 person-years. The event rates of CHD in men were significantly higher than those in women, in categories B4 (p < 0.001) and C (p < 0.001). From these results, each category classified by accumulation of risk factors, showed increasing event rates of CHD and CVD. The categories in the JAS guidelines are useful to assess CHD and CVD risk in Japanese patients with hypercholesterolemia. However, the risk evaluation by the JAS guideline categories may underestimate the risk in men and overestimate it in women.

Effect of carbocysteine on cough reflex to capsaicin in asthmatic patients.

AIMS: Cough, one of the main symptoms of bronchial asthma, is a chronic airway inflammatory disease with functionally damaged bronchial epithelium. Recently, we established an animal model with cough hypersensitivity after antigen challenge and clearly showed the protective effect of carbocysteine in this model. This study was designed to investigate the clinical effect of carbocysteine for cough sensitivity in patients with bronchial asthma. METHODS: The effects of the two orally active mucoregulatory drugs, carbocysteine and ambroxol hydrochloride, on cough response to inhaled capsaicin were examined in 14 patients with stable asthma. Capsaicin cough threshold, defined as the lowest concentration of capsaicin eliciting five or more coughs, was measured as an index of airway cough sensitivity. RESULTS: Geometric mean values of the cough threshold at run-in (baseline) and after 4 weeks' treatment of placebo, 1500 mg day-1 of carbocysteine and 45 mg day-1 of ambroxol hydrochloride were 12.8 micro M (95% confidence interval [CI] 5.5, 29.6), 11.0 micro M (95% CI 4.4, 27.5), 21.0 micro M (95% CI 8.8, 50.2) and 11.6 micro M (95% CI 5.8, 23.3), respectively. The cough threshold for carbocysteine was significantly greater than those of ambroxol hydrochloride (P = 0.047) and placebo (P = 0.047), respectively. CONCLUSIONS: These findings indicate that carbocysteine administration may be a novel therapeutic option for asthmatic patients, especially with cough variant asthma.

Thromboxane antagonism and cough in chronic bronchitis.

BACKGROUND: The increased eicosanoid synthesis has been suggested as the underlying mechanism of chronic productive cough in patients with chronic bronchitis. METHOD: The effects of the orally active thromboxane A2 (TxA2) receptor antagonist seratrodast and the cysteinyl leukotrienes (cLTs) receptor antagonist pranlukast on cough response to inhaled capsaicin were examined in sixteen patients with stable chronic bronchitis. Capsaicin cough threshold, defined as the lowest concentration of capsaicin eliciting five or more coughs, was measured as an index of airway cough sensitivity. RESULTS: The cough threshold was significantly increased compared with placebo after four-week treatment with seratrodast, but not after treatment with pranlukast. CONCLUSIONS: TxA2, but not cLTs, may be a possible modulator augmenting airway cough sensitivity in chronic bronchitis. Thromboxane antagonism may be considered to be one of the therapeutic options for the treatment of chronic productive cough.

Long-term treatment with pitavastatin (NK-104), a new HMG-CoA reductase inhibitor, of patients with heterozygous familial hypercholesterolemia.

The clinical efficacy and safety of pitavastatin (NK-104), a novel HMG-CoA reductase inhibitor, during long-term treatment, were examined in 25 patients (male/female=11/14, mean age=53+/-13 (mean+/-SD) years) with heterozygous familial hypercholesterolemia (FH). After a period on placebo of >4 weeks, 2 mg/day of pitavastatin was administered for 8 weeks, and the dose was increased to 4 mg/day for up to 104 weeks. Total cholesterol (TC) decreased by 31% from the initial value of 340+/-57 to 237+/-40 mg/dl (P<0.0001) at week 8. During treatment with the higher dose, TC decreased even further to 212+/-35 mg/dl at week 12; it decreased by 37% from the initial value (P<0.0001). Similarly, the baseline low-density lipoprotein (LDL)-cholesterol (LDL-C) decreased by 41% at week 8, and by 49% at week 12, from 267+/-61 mg/dl at baseline. These findings indicate a dose-dependent effect of the drug on TC and LDL-C concentrations. To examine whether the levels of circulating matrix metalloproteinases (MMPs) and their endogenous inhibitors (tissue inhibitors of metalloproteinases: TIMPs) are altered during lipid-lowering therapy, we also measured their plasma levels. The mean levels of MMP-2 and -3 were significantly increased. No significant alteration was found in MMP-9, TIMP-1 and -2 levels. As for the safety of pitavastatin, adverse reactions were observed in one case (4%) of subjective and objective symptoms. The effects of pitavastatin on TC and LDL-C were stable during long treatment of patients with heterozygous FH.