A prospective study of frequency and characteristics of cough during ACE inhibitor treatment.

Angiotensin converting enzyme (ACE) inhibitors are reportedly effective, and positively indicated in patients with chronic heart failure with decreased contractility, after myocardial infarction, after cerebrovascular disorders, and in those with chronic kidney disease. However, the biggest challenge to continuous use of ACE inhibitors is the adverse reaction of cough. Accordingly, in the present study, we investigated the present state and characteristics of ACE inhibitor-induced cough in patients with essential hypertension currently being treated with an ACE inhibitor for an average of 18 months, who could be regularly checked for cough. Subjects in this study were 176 patients overall (mean age 67 ± 11 years old), 90 men and 86 women. The adverse reaction of cough was observed in 20% of patients, and more frequently in women than in men. However, in 26 of the patients with cough, the cough either resolved naturally or completely disappeared while the treatment continued, after which patients could continue taking the medication. Specifically, ACE inhibitor treatment was eventually discontinued due to cough in 5.1% of patients. Cough occurred less frequently with concomitant calcium antagonists or diuretics than with ACE inhibitor monotherapy. Cough as an adverse reaction occurred at a low frequency when medication was taken at bedtime. We considered a number of measures to counteract cough, then in addition to starting the ACE inhibitor treatment as early as possible, it is important to devise ways for the ACE inhibitor treatment to be continued for as long as possible, through the adept use of these measures.

Effect of aldosterone breakthrough on albuminuria during treatment with a direct renin inhibitor and combined effect with a mineralocorticoid receptor antagonist.

We have reported observing aldosterone breakthrough in the course of relatively long-term treatment with renin-angiotensin (RA) system inhibitors, where the plasma aldosterone concentration (PAC) increased following an initial decrease. Aldosterone breakthrough has the potential to eliminate the organ-protective effects of RA system inhibitors. We therefore conducted a study in essential hypertensive patients to determine whether aldosterone breakthrough occurred during treatment with the direct renin inhibitor (DRI) aliskiren and to ascertain its clinical significance. The study included 40 essential hypertensive patients (18 men and 22 women) who had been treated for 12 months with aliskiren. Aliskiren significantly decreased blood pressure and plasma renin activity (PRA). The PAC was also decreased significantly at 3 and 6 months; however, the significant difference disappeared after 12 months. Aldosterone breakthrough was observed in 22 of the subjects (55%). Urinary albumin excretion differed depending on whether breakthrough occurred. For the subjects in whom aldosterone breakthrough was observed, eplerenone was added. A significant decrease in urinary albumin excretion was observed after 1 month, independent of changes in blood pressure. In conclusion, this study demonstrated that aldosterone breakthrough occurs in some patients undergoing DRI therapy. Aldosterone breakthrough affects the drug's ability to improve urinary albumin excretion, and combining a mineralocorticoid receptor antagonist with the DRI may be useful for decreasing urinary albumin excretion. When the objective is organ protection in hypertensive patients, a two-pronged approach using combination therapy to inhibit both the RA system and aldosterone may be highly effective.

A case of membranous nephropathy with primary biliary cirrhosis and cyclosporine-induced remission.

We report a case of membranous nephropathy with primary biliary cirrhosis (PBC). A 76-year-old Japanese man had been treated for PBC and was referred to our department because of acute severe proteinuria (10 g/day). Renal biopsy was performed and was compatible with a diagnosis of membranous nephropathy. The patient was treated with cyclosporine A (CsA; Neoral®), which was followed by normalization of liver function and partial remission of proteinuria (0.68 g/day) within six months without any significant side effects. This case suggests that CsA monotherapy is effective for the treatment of both liver dysfunction and membranous nephropathy associated with PBC.

Defective glycosylation of α-dystroglycan contributes to podocyte flattening.

In addition to skeletal muscle and the nervous system, α-dystroglycan is found in the podocyte basal membrane, stabilizing these cells on the glomerular basement membrane. Fukutin, named after the gene responsible for Fukuyama-type congenital muscular dystrophy, is a putative glycosyltransferase required for the post-translational modification of α-dystroglycan. Chimeric mice targeted for both alleles of fukutin develop severe muscular dystrophy; however, these mice do not have proteinuria. Despite the lack of a functional renal defect, we evaluated glomerular structure and found minor abnormalities in the chimeric mice by light microscopy. Electron microscopy revealed flattening of podocyte foot processes, the number of which was significantly lower in the chimeric compared to wild-type mice. A monoclonal antibody against the laminin-binding carbohydrate residues of α-dystroglycan did not detect α-dystroglycan glycosylation in the glomeruli by immunoblotting or immunohistochemistry. In contrast, expression of the core α-dystroglycan protein was preserved. There was no statistical difference in dystroglycan mRNA expression or in the amount of nephrin and α3-integrin protein in the chimeric compared to the wild-type mice as judged by immunohistochemistry and real-time RT-PCR. Thus, our results indicate that appropriate glycosylation of α-dystroglycan has an important role in the maintenance of podocyte architecture.

Aldosterone-induced kidney injury is mediated by NFκB activation.

BACKGROUND: Aldosterone induces inflammation and fibrosis in the kidney, while nuclear factor κB (NFκB) plays key roles in inflammation mediated by various cytokines. Here, we determined the roles of NFκB activation in aldosterone-induced kidney injury. METHODS: We used unilaterally nephrectomized rats with or without continuous aldosterone infusion and 0.9% saline as drinking water for 3 weeks. IMD-1041, an IKKß inhibitor, and spironolactone were orally administered to inhibit NFκB and mineralocorticoid receptor, respectively. RESULTS: The aldosterone-infused rats exhibited severe kidney injury, hypertension, and increased expression of pro-inflammatory and fibrotic proteins, osteopontin, fibrinogen, collagen type I, and PAI-1. Western blotting confirmed NFκB activation by aldosterone by the increased amount of p65 in the nuclear fraction of the kidney, and oral IMD-1041 prevented the kidney injury and lessened the increase in pro-inflammatory and fibrotic proteins without significant changes in blood pressures. In addition, changes in angiotensin-converting enzyme 2 (ACE2), which has been found to act as a protective factor in various kidney injury models, were examined. Immunofluorescence studies revealed the presence of ACE2 in the brush-border membrane of the proximal convoluted tubules and markedly blunted ACE2 staining in aldosterone-infused rats. The decrease in amount of ACE2 protein was confirmed by Western blotting, and IMD-1041 also prevented the decrease in ACE2. The administration of spironolactone also abolished the effects of aldosterone. CONCLUSION: Our results suggest that aldosterone induces kidney injury via activation of NFκB and mineralocorticoid receptor, and that decreased ACE2 expression may play an important role in aldosterone-induced kidney injury.

Plasma adiponectin: a predictor of coronary heart disease in hemodialysis patients--a Japanese prospective eight-year study.

BACKGROUND/AIM: Plasma adiponectin may play a protective role in the pathogenesis of cardiovascular disease in hemodialysis (HD) patients. We examined the effect of plasma adiponectin levels on the prognosis of the HD patients. METHODS: 68 HD patients (male:female = 38:30) were subjected to plasma adiponectin measurement in 1998 and followed up over 8 years. RESULTS: Plasma adiponectin concentrations differed between male and female patients (9.3 vs. 15.7 microg/ml). The plasma adiponectin concentration as a whole was positively correlated with serum high-density lipoprotein cholesterol and negatively with serum creatinine and waist circumference. During an 8-year follow-up, the cardiac events occurred in 7 of 38 men and in 10 of 30 women. Cox's proportional hazard model analysis in a stepwise manner revealed that coronary heart disease (CHD) was associated with intact parathyroid hormone concentration, age, and the presence of diabetes in men whereas plasma adiponectin concentration was the most powerful single predictor in women. The impact of the plasma adiponectin concentration was strengthened by Kaplan-Meier survival analysis. In the group with a lower plasma adiponectin concentration, CHD events were significantly increased in men (p = 0.043) and in women (p = 0.007). CONCLUSION: Plasma adiponectin concentration may predict CHD outcomes in HD patients.

Spironolactone in combination with cilazapril ameliorates proteinuria and renal interstitial fibrosis in rats with anti-Thy-1 irreversible nephritis.

Blockade of the renin-angiotensin system has been established as a treatment for heart failure with hypertension and left ventricular hypertrophy, and for progressive kidney diseases. The present study was conducted to examine whether spironolactone, a mineralocorticoid receptor antagonist, alone or in combination with cilazapril, an angiotensin converting enzyme (ACE) inhibitor, ameliorates proteinuria and renal lesions in an immune-initiated progressive nephritis model. Wistar rats were uninephrectomized 7 days before injection of anti-Thy-1 monoclonal antibody 1-22-3 to induce progressive glomerulonephritis. The nephritic rats were untreated or treated with spironolactone (400 mg/kg body weight/day), cilazapril (1 mg/kg body weight/day), or both for 10 weeks. Proteinuria was increased in the untreated rats 1 week after nephritis induction and was maintained throughout the experiment. Compared with the untreated animals (212.9+/-49.2 mg/day), proteinuria was significantly reduced in the spironolactone-treated group (62.0+/-4.0 mg/day, p=0.0046) and the cilazapril-treated group (71.8+/-26.0 mg/day, p=0.0048) on day 70 after antibody injection. Further reduction of proteinuria (42.4+/-4.5 mg/day, p=0.0019 vs. the untreated group) and less renal cortex interstitial fibrotic change (fibrosis score: 142.0+/-18.4 vs. 80.3+/-18.5 in the untreated group, p=0.0123) were detected in the spironolactone plus cilazapril-treated group. Blood pressure did not differ among the three treatment groups. In conclusion, spironolactone ameliorates proteinuria to the same degree as cilazapril, and concomitant use of spironolactone and an ACE inhibitor further suppresses renal disease progression. These data suggest that concomitant treatment with spironolactone and an ACE inhibitor has beneficial effects on immune-initiated progressive kidney disease.