Blood pressure control in a Japanese population with chronic kidney disease: a baseline survey of a nationwide cohort

BACKGROUND

Hypertension is a key risk factor for adverse renal outcomes in chronic kidney disease (CKD), and strict blood pressure control is recommended to halt its progression. This study assessed blood pressure control in the Japanese CKD population.

METHODS

We used a nationwide database of 250,130 subjects (aged 20-88), including 45,845 CKD subjects (18.3%), participated in an annual health check, "The Specific Health Check and Guidance in Japan," and examined the relationship between CKD status and blood pressure. Blood pressures were measured in sitting position by trained staff, and target blood pressure for CKD subjects was defined as systolic (SBP)/diastolic blood pressure (DBP) <130/80 mm Hg.

RESULTS

In total population, CKD subjects had a higher prevalence of hypertension (58.0% vs. 41.8%, P < 0.001) and a higher proportion with antihypertensive medication (42.4% vs. 26.7%, P < 0.001), compared with non-CKD subjects. The proportion of subjects achieving target blood pressure was significantly lower among total CKD subjects than among total non-CKD subjects (34.6% vs. 43.8%, P ≤ 0.001). Among CKD subjects, these proportions were especially low in those with stage 4-5 (24.3-27.5%), those on antihypertensive medication (21.6%) and those with proteinuria ≥2± (21.3%). Logistic regression analysis showed that independent factors for high-blood pressure in CKD subjects were age, male gender, alcohol consumption, nonsmoking, diabetes, dyslipidemia, obesity, proteinuria, and antihypertensive medication.

CONCLUSIONS

Blood pressure control was inadequate in the majority of Japanese CKD subjects, despite antihypertensive treatment. More aggressive efforts to achieve target blood pressures among CKD subjects are recommended.

Positron annihilation in hydrogen-doped alkali-metal fullerides

Hydrogen-doped alkali-metal fullerides were studied by means of mass-analyzed thermal desorption and positron annihilation. The hydrogen desorption spectra reveal the inclusion of hydrogen in the fullerides as two types of components; one weakly adsorbed and the other strongly bound, probably as hydride ion. The positron lifetime spectra demonstrate that hydrogen-doping to alkali-metal fullerides increases a concentration of higher-order vacancy-type defects, through which more than 50% injected positrons decay with a lifetime of 0.42–0.71 ns.

Anti-tumor necrosis factor therapy in patients with difficult-to-treat lupus nephritis: a prospective series of nine patients

OBJECTIVE

To clarify the efficacy and safety of anti-TNF-alpha therapy for intractable lupus nephritis.

METHODS

In nine patients with systemic erythematosus who presented with lupus nephritis resistant to steroids and immunosuppressants, 200 mg/body of infliximab was drip-infused three times. No changes were made to other treatments for three months after the start of anti-TNF-alpha therapy, and urinary findings, renal function, serum complement, anti-DNA antibody, SLE activity, and adverse events were examined for six months after the start of anti-TNF-alpha therapy.

RESULTS

One of the nine patients developed pyelonephritis after the first infliximab injection and received no further injections. The remaining eight patients received 3 infliximab injections. Of the eight patients, urinary protein decreased after anti-TNF-alpha therapy in six patients, and the SLEDAI improved in five patients. Urinary findings and/or SLE activity improved in six patients. Of the patients whose urinary protein levels decreased after anti-TNF-alpha therapy, proteinuria recurred six months after anti-TNF-alpha therapy in one patient. After anti-TNF-alpha therapy, proteinuria and the SLEDAI improved significantly. With respect to adverse events, therapy was discontinued in one patient who developed pyelonephritis, and one patient developed decreased blood pressure due to infusion reactions. In one patient in whom the steroid dosage was increased due to poor response to anti-TNF-alpha therapy, brainstem infarction occurred four months later. In one patient, anti-DNA antibody levels increased after therapy, but none of the patients had decreased serum complement levels or increased SLE activity.

CONCLUSION

In intractable lupus nephritis, anti-TNF-alpha therapy improved urinary protein levels and SLE activity. Although adverse events must be monitored cautiously, it may be possible to use anti-TNF-alpha therapy as a third-line treatment.

Expression profiling of genes related to asthma exacerbations

BACKGROUND

Asthma is a chronic airway inflammatory disease; however, the molecular mechanisms that underlie asthma exacerbation are only partially understood.

OBJECTIVE

To identify gene expression signatures that reflect the acute exacerbation of asthma, we examined the differential expression of genes during asthma exacerbation and stable condition by using microarray analysis.

METHODS

The subjects were mite-sensitive asthmatic children and non-asthmatic control children. The children were divided into four groups (AE: asthma exacerbation, n=12; SA: stable asthma, n=11; IC: infected control, n=6; and NC: non-infected control, n=5). Total RNA was extracted from peripheral blood mononuclear cells and subjected to microarray analysis with Illumina Human Ref8 BeadChip arrays. Welch's t-test was performed to identify genes whose expression was altered during asthma exacerbation. Quantitative real-time RT-PCR was performed on samples collected from 43 asthmatic children and 11 control children to verify the microarray results.

RESULTS

The expression of 137/16 genes was significantly up/down-regulated during asthma exacerbation assessed by microarray analysis. Of the genes, 62 were also differentially expressed during upper respiratory infection. Many of the asthma exacerbation related genes were involved in defence responses and responses to external stimuli, but these associations disappeared after excluding the infection-related genes. Quantitative real-time RT-PCR confirmed that the genes related (S100A8 and GAS6) and unrelated to infections (CD200 and RBP7) were differentially expressed during asthma exacerbation (P<0.01).

CONCLUSIONS

Previously unidentified immune responses during asthma exacerbation may provide further clarification of the molecular mechanisms underlying asthma.

Involvement of REG Ialpha protein in the regeneration of ductal epithelial cells in the minor salivary glands of patients with Sjögren's syndrome

The regenerating gene (Reg) was originally isolated from regenerating rat pancreatic islets and revealed recently to constitute a multi-gene family in humans. REG Ialpha protein is known to be overexpressed not only in various human inflammatory diseases but also in various experimental models of inflammation in animal tissues. However, its involvement in pathophysiology of the minor salivary gland (MSG) is not clear. We investigated REG Ialpha expression in the MSG of patients with primary Sjögren's syndrome (SS) and assessed its role in ductal epithelial cell proliferation in such tissues. Lip biopsy specimens were obtained from 40 patients with primary SS and examined using immunohistochemistry for REG Ialpha protein, Ki67 and single-strand DNA (ssDNA). The relationships among clinicopathological factors and expression of REG Ialpha protein, Ki67 and ssDNA in the MSG were then analysed. REG Ialpha protein was expressed rarely in ductal epithelial cells of the normal MSG but was apparently overexpressed in those of patients with SS. The labelling indices for both Ki67 and ssDNA in the ductal cells of the MSGs were significantly higher in SS patients than in controls. Moreover, these labelling indices were significantly higher in REG Ialpha-positive than in negative SS patients. REG Ialpha protein may play a role in the regeneration of ductal epithelial cells in the MSGs of patients with SS.

Enhanced desensitization efficacy by liposomal conjugation of a specific antigen

Since liposomes are known as strong adjuvants, we attempted to use liposomes in immunotherapy as adjuvants, and to achieve desensitization in pre-sensitized mice. At first, we sensitized mice with intraperitoneal injection of model antigen, 100 microg ovalbumin (OVA), with Alum and treated them with liposome composed of distearoylphosphatidylcholine (DSPC) and cholesterol (2:1 as a molar ratio), which was coupled with a small amount of OVA (10 microg OVA in 400 nmol DSPC and 200 nmol cholesterol-liposome was injected into 20 g mouse). It is well known that antigen-specific immunotherapy increases IgG blocking antibodies and decreases in IgE antibodies. The treatment with i.v. injection of OVA-liposome at days 8, 10, and 12 after sensitization strongly suppressed OVA-specific IgE production without affecting IgG level after the boost (100 microg OVA with Alum). Moreover, the treatment with high-density OVA-liposome (10 microg OVA in 80 nmol DSPC and 40 nmol cholesterol-liposome/20 g mouse) not only strongly suppressed IgE levels but also reduced IgG production after the boost of OVA-sensitized mice suggesting the importance of liposomal characteristic in desensitization immunotherapy. Next we reduced the dose of OVA-liposome and the desensitization effect was also observed at the dose of as low as 1 microg OVA on OVA-liposome/mouse. On the contrary, free OVA did not affect the production of both IgG and IgE levels. Biodistribution study indicated that OVA-liposome was highly accumulated in spleen of OVA-sensitized mice compared to control liposome at 3 h after i.v. injection. These results suggest that the liposomal OVA effectively interacts with and desensitizes immune cells, therefore, liposomes coupling with a certain antigen may be effective in allergy immunotherapy.

ADAM33 polymorphisms are associated with asthma susceptibility in a Japanese population

BACKGROUND

Asthma is the most common chronic disorder in childhood, and asthma exacerbation is an important cause of childhood morbidity and hospitalization. Asthma is believed to be a complex disorder involving genetic and environmental factors, and several asthma susceptibility loci have been identified through genome-wide screening. A disintegrin and metalloprotease 33 (ADAM33) was the first asthma susceptibility gene to be discovered by positional cloning in 2002.

OBJECTIVE

The aim of the present study was to investigate whether single-nucleotide polymorphisms (SNPs) in ADAM33 are associated with childhood asthma in the Japanese population.

METHODS

Twenty-three ADAM33 SNPs were genotyped by fluorescence correlation spectroscopy with the use of DNA from 155 families (538 members) identified through children with atopic asthma. The transmission disequilibrium test (TDT) was performed for family-based association study.

RESULTS

TDT revealed that minor alleles of S+1, ST+4, and T2 SNPs were over-transmitted to asthma-affected offspring (P<0.05). According to the haplotype TDT, no haplotype of ADAM33 was transmitted preferentially to asthmatic offspring.

CONCLUSION

Our results confirm the involvement of ADAM33 in the development of childhood asthma among the Japanese.

Prevalence and risk factor analysis of microalbuminuria in Japanese general population: the Takahata study

Microalbuminuria, an indicator of glomerular injury, is associated with increased risk of progressive renal deterioration, cardiovascular disease, and mortality. However, the prevalence of microalbuminuria in Japanese general population is less certain. Thus, we examined the prevalence of microalbuminuria and its associated risk factors in Japan. Subjects of this cross-sectional study were asymptomatic individuals over 40 years in Takahata, Japan. Urine albumin-creatinine ratio was calculated from a single-spot urine specimen collected in the morning. Creatinine clearance (CCr) was obtained by Cockcroft-Gault equation. Multivariate logistic regression analysis was used to determine which risk factors (i.e., age, hypertension, diabetes, obesity, and salt intake) might predict the presence of microalbuminuria. A total of 2321 subjects (mean age, 64 years; men, 1034; women, 1287) were entered into the final analysis. Among them, the prevalence of microalbuminuria, macroalbuminuria, and proteinuria by dipstick test (> or = 1+) were 317 (13.7%), 39 (1.7%), and 103 (4.4%), respectively. Age, hypertension, and diabetes were independently associated with microalbuminuria in men. In addition to the classical risk factors detected in men, estimated 24-h urinary sodium excretion and uric acid were also independently associated with microalbuminuria in women. Among the 668 subjects with renal insufficiency (CCr <60 ml/min/1.73 m(2)), the prevalence of microalbuminuria and macroalbuminuria were 119 (17.8%) and 18 (2.7%), respectively. In conclusion, microalbuminuria is prevalent across all age groups and is associated with lifestyle-related risk factors in Japanese general population. However, there are a substantial number of subjects with renal insufficiency accompanying no microalbuminuria.