Ryota Ikee

Weekly Averaged Blood Pressure Is More Important than a Single-Point Blood Pressure Measurement in the Risk Stratification of Dialysis Patients

BACKGROUND AND OBJECTIVES With regard to monitoring blood pressure in hemodialysis patients, it is important to define clearly the time point at which the blood pressure is measured, because the blood pressure of hemodialysis patients varies with each hemodialysis session as a result of loss of excess fluid. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS Using weekly averaged blood pressure, 96 hemodialysis patients were studied prospectively for 35 mo. All patients were followed up for cardiovascular events or death from all causes. RESULTS Pulse weekly averaged blood pressure and age at enrollment were significantly higher and parathyroid hormone level was significantly lower in patients with cardiovascular events compared with those without cardiovascular events; however, none of the components of pre- or postdialysis blood pressure was significantly different between patients with and without cardiovascular events. Pulse weekly averaged blood pressure, prepulse pressure, age, and human atrial natriuretic peptide were significantly higher in patients who died than in survivors. Kaplan-Meier method with a log-rank test demonstrated that survival free rate from cardiovascular events and that of all-cause mortality in patients with pulse weekly averaged blood pressure > or =70 mmHg were significantly lower than those in the remaining patients. CONCLUSIONS One-point measurement of blood pressure is insufficient to evaluate hypertension and prognosis of hemodialysis patients, and weekly averaged blood pressure is a useful marker because of averaging fluctuations of blood pressure during 1 wk. Among components of weekly averaged blood pressure, pulse weekly averaged blood pressure could be a good prognostic marker of the incidence of both cardiovascular events and all-cause mortality in hemodialysis patients.

Coronary Artery Calcification, ADMA, and Insulin Resistance in CKD Patients

BACKGROUND AND OBJECTIVES It is known that coronary artery calcification (CAC) develops in chronic kidney disease (CKD) before initiation of renal replacement therapy, and factors associated with CKD mineral and bone disorders (CKD-MBDs) are involved. However, little information is available about any association between plasma levels of asymmetric dimethylarginine (ADMA), insulin resistance, and CAC. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS A total of 111 CKD patients (79 men, 32 women; glomerular filtration rate [GFR] median, 33.7 ml/min per 1.73 m(2)), free of cardiovascular disease, were consecutively recruited along with 30 age-matched healthy subjects. Coronary artery calcification scores (CACS) were measured by multidetector-row CT according to Agatston score. RESULTS In CKD patients, CACS was distributed widely from 0 to 2901, while in age-matched, healthy control subjects (n = 30), CACS showed a range from 0 to 307. GFR had a significant negative correlation with CACS. Plasma ADMA levels were negatively correlated with GFR and positively correlated with CACS. When CACS was divided into quartiles (<50, n = 56; 50 to 300, n = 24; 300 to 600, n = 14; >600, n = 17), the patients with CACS >600 had significantly higher values of HOMA-IR, plasma ADMA levels, and fibrinogen along with serum levels of phosphorus, compared with those in patients having CACS <50. Multivariate regression analysis determined HOMA-IR as an independent contributing factor to CACS. CONCLUSIONS CAC becomes more prevalent and severe with a decline in GFR, and plasma ADMA levels and insulin resistance, independent of factors associated with CKD-MBD, are correlated with CAC.

Impact of coronary artery calcification in hemodialysis patients: Risk factors and associations with prognosis.

The risk factors of coronary artery calcification (CAC) and the impact of CAC on cardiovascular events, cardiovascular deaths, and all‐cause deaths in hemodialysis (HD) patients have not been fully elucidated. We examined the CAC score (CACS) in 74 HD patients using electron‐beam computed tomography. Fifty‐six patients underwent a second electron‐beam computed tomography after a 15‐month interval to evaluate CAC progression. We evaluated (1) the risk factors for CAC and its progression and (2) the impact of CAC on the prognosis. In the cross‐sectional study, HD vintage and high‐sensitive C‐reactive protein (hsCRP) were the independent risk factors for CAC. In the prospective cohort study, delta CACS (progression of CAC) was significantly correlated with hsCRP, fibrinogen, and serum calcium level in the univariate analysis. Stepwise multiple regression analysis revealed that only hsCRP was the independent risk factor for CAC progression in HD patients. Kaplan‐Meier survival analysis revealed that cardiovascular events (P<0.0001), cardiovascular deaths (P=0.039), and all‐cause deaths (P=0.026) were significantly associated with CACS. In conclusion, CAC had significantly progressed in HD patients during the 15‐month observation period. Microinflammation was the only independent risk factor for CAC progression in HD patients. The advanced CAC was a significant prognostic factor in HD patients, i.e., which was strongly associated with future cardiovascular events, cardiovascular deaths, and all‐cause deaths.

Fractalkine and its receptor, CX3CR1, upregulation in streptozotocin-induced diabetic kidneys.

Background: Fractalkine is induced on activated endothelial cells and promotes strong adhesion of T cells and monocytes via its receptor CX3CR1. In kidney, fractalkine expression might be induced by high shear stress and play an important role in prolonged glomerular diseases. We examined whether fractalkine and CX3CR1 upregulation are found in streptozotocin-induced diabetic kidneys. Methods: Diabetic rats were randomized to receive an angiotensin-converting enzyme inhibitor (temocapril), aminoguanidine or no treatment. Reverse transcription-competitive polymerase chain reaction, Western blot analysis and immunohistochemistry were used. Results: At 4 weeks, fractalkine and CX3CR1 mRNA expression in diabetic kidneys increased compared with that in controls. Fractalkine staining in diabetic kidneys was clearly detected, along with glomerular capillary lumen and peritubular capillaries. A few CX3CR1 positive cell infiltration in diabetic glomeruli were found. Treatment with temocapril or aminoguanidine did not affect these changes. At 8 weeks, fractalkine and CX3CR1 mRNA expression in untreated diabetic kidneys markedly increased compared with that in controls. Membrane-anchored fractalkine protein expression in untreated diabetic rats also increased. The increased expression was suppressed by the treatment with temocapril and aminoguanidine. Increased CX3CR1-positive cell infiltration in diabetic glomeruli was also inhibited by both treatments. Some CX3CR1-positive cells were ED3 positive. Conclusions: Fractalkine and CX3CR1 upregulation were demonstrated in an early stage of diabetic kidney. These upregulation, as well as urinary albumin excretion, were suppressed by treatments with temocapril and aminoguanidine for 8 weeks. These findings suggest that fractalkine expression and CX3CR1-positive cell infiltration in diabetic kidneys might play an important role for progression of diabetic nephropathy.

Involvement of Transglutaminase-2 in Pathological Changes in Renal Disease

Background: Transglutaminase (Tg)-2 is shown to be related to renal fibrosis. However, its roles in human kidney disease have not been fully studied. Methods: Using immunohistochemistry, we examined Tg-2 expression in renal biopsy specimens from 22 patients with IgA nephropathy (IgAN) and correlated the intensity of Tg-2 staining with clinical and histopathological parameters. We compared the distribution and intensity of Tg-2 staining with those of transforming growth factor (TGF)-β staining. Results: In normal human kidneys, Tg-2 staining was not significant. In IgAN kidneys, glomerular Tg-2 staining correlated with serum creatinine (S-Cr), creatinine clearance (Ccr), urinary protein excretion, glomerular sclerosis, and mesangial cell proliferation. Tubulointerstitial Tg-2 correlated with S-Cr, Ccr, N-acetyl-β-glucosaminidase, urinary β2-microglobulin, and tubulointerstitial injuries. Tg-2 staining in the vicinity of vascular poles of glomeruli preceded the development of mesangial lesions, and was more remarkable in cases with renal impairment. The distribution and intensity of Tg-2 staining were not consistent with those of TGF-β staining. In glomerular crescents, Tg-2 staining was remarkable. Conclusion: The present study showed a correlation between Tg-2 expression and renal function and pathological changes. Tg-2 expression in the vicinity of vascular poles was notable because that may be an initial marker of glomerular injury.

Impact of hypertension and hypertension-related vascular lesions in IgA nephropathy.

It remains poorly understood whether vascular pathology plays an important role in the progression of renal parenchymal disease in humans. Moreover, in the case of hypertensive patients with mild proteinuria, nephrologists tend to make a diagnosis of benign nephrosclerosis without renal biopsy. Among 172 patients who were treated at our hospital for biopsy-proven IgA nephropathy, we performed quantitative histopathological analysis in 38 patients with mild proteinuria of less than 0.5 g/day. We related these histopathological parameters with clinical data at biopsy and also with follow-up data. The percentage of glomeruli showing global sclerosis exceeded 10% of total glomeruli in 15 of the patients (39.5%) and exceeded 20% in 9 (23.7%). Arteriosclerosis and tubulointerstitial changes significantly correlated with glomerular sclerosis, but mesangial cell proliferation did not. Among the 38 patients, the 12 with hypertension showed more severe glomerular sclerosis, tubulointerstitial changes and arteriosclerosis compared with the 26 without hypertension, but the mesangial cell proliferation was identical between the two groups. Stepwise multiple regression analysis revealed that hypertension and urinary protein excretion (UPE) were independent risk factors for arteriosclerosis. The follow-up data of a mean period of 27.6 months showed that 9 of the 38 patients (23.7%) had an increase in UPE. Hypertension, arteriosclerosis, age, and UPE at biopsy were selected as the important risk factors for an increase in UPE in the follow-up. Our results provide not only clinical but histopathological evidence that hypertension affects the prognosis of mild proteinuric nephropathy through vascular lesions.

Serum Biological Antioxidant Potential Predicts the Prognosis of Hemodialysis Patients

Background: It is well known that oxidative stress is enhanced in patients with end-stage renal disease. However, little is known about the relationship between serum antioxidant capacity and clinical outcome in hemodialysis (HD) patients. Methods: We examined the relationship between serum biomarkers of oxidative stress and clinical outcomes including all-cause mortality, hospitalization rate and incidence of cardiovascular events in HD patients. As biomarkers of oxidative stress, we measured serum levels of coenzyme Q10 (CoQ10) and biological antioxidant potential (BAP). Results: 108 patients were observed for 30 months as the follow-up periods. The survival group (n = 83) showed significantly higher BAP values compared with those in death groups (n = 25; p < 0.05). When serum BAP levels were divided into two groups by their median value, the group with higher BAP values had a better survival rate than that with lower BAP values on the Kaplan-Meier survival analysis (p = 0.05). Although serum levels of CoQ10 did not show any association with clinical outcomes, lower BAP was selected as an independent risk factor for all-cause mortality as well as the absence of angiotensin-converting enzyme inhibitors/angiotensin II receptor blockers therapy by age-adjusted Cox regression analysis. Conclusions: This study indicated that BAP could predict the prognosis of HD patients.

Pathological Regression by Angiotensin II Type 1 Receptor Blockade in Patients with Mesangial Proliferative Glomerulonephritis

Although angiotensin II type 1 receptor blocker (ARB) therapy reduces proteinuria and retards the progression of renal injury in patients with glomerulonephritis, whether these drugs actually ameliorate pathological damages in human glomerulonephritis has not been determined. Fifteen patients with biopsy-proven mild-to-moderate mesangial proliferative glomerulonephritis (10 with immunoglobulin A [IgA] nephropathy and 5 with non-IgA mesangial proliferative glomerulonephritis) received ARB monotherapy. In these patients, repeated renal biopsy was performed after a mean of 28.1 months, and pathological changes (including the mesangial matrix expansion ratio and interstitial fibrosis expansion ratio) were quantitatively examined using an image analyzer. Clinical markers were also evaluated, including the serum creatinine, serum IgA, creatinine clearance (Ccr), 24-h urinary protein excretion, urinary N-acetyl-β-D-glucosaminidase (NAG), and blood pressure. ARB therapy significantly reduced urinary protein excretion (0.68±0.63 to 0.20±0.32 g/day, p=0.016) and the blood pressure (systolic: 133.3±18.2 to 123.4±10.5 mmHg, p=0.041; diastolic: 79.4±11.9 to 72.0±8.2 mmHg, p=0.038). Although the global glomerular sclerosis ratio was unchanged (6.3±8.5% to 10.7±16.1%, p=0.33), the mesangial matrix expansion ratio (33.1±10.8% to 22.7±7.8%, p=0.001) and the interstitial fibrosis ratio (19.9±5.8% to 13.8±4.4%, p=0.034) were significantly reduced by ARB treatment. The levels of pathological improvement were similar between patients with IgA nephropathy and those with non-IgA mesangial proliferative glomerulonephritis. The results of the present study strongly suggest that ARB monotherapy can significantly reverse pathological changes, including mesangial matrix expansion and interstitial fibrosis, in human glomerulonephritis.

Amyloidosis associated with chronic lymphocytic leukemia.

Chronic lymphocytic leukemia (CLL), the most common form of leukemia in Western countries, rarely induces glomerular disease, but membranoproliferative glomerulonephritis or immunotactoid glomerulopathy has been reported. The proliferating cells in CLL are of mature B-cell origin and produce monoclonal immunoglobulin (Ig), thus leading to various kinds of autoimmune disorders or immunotactoid glomerulopathy. Although there have been a few reported cases of amyloidosis accompanying CLL, the type of amyloid fibrils has not been demonstrated nor described in detail, particularly regarding monoclonal Ig productivity. We report a rare case of amyloidosis associated with CLL, in which we detected κ-light chain type monoclonal Ig in the sera, urine, and on the surface membrane of lymphocytes, and discuss an association between monoclonal Ig-related disease and non-Hodgkins lymphoma.

A novel mechanism in maggot debridement therapy: protease in excretion/secretion promotes hepatocyte growth factor production

Maggot debridement therapy (MDT) is effective for treating intractable wounds, but its precise molecular mechanism, including the association between MDT and growth factors, remains unknown. We administered MDT to nine patients (66.3 ± 11.8 yr, 5 male and 4 female) with intractable wounds of lower extremities because they did not respond to conventional therapies. Significant increases of hepatocyte growth factor (HGF) levels were observed in femoral vein blood during 48 h of MDT (P < 0.05), but no significant change was found for vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), transforming growth factor-β1 (TGF-β1), or tumor necrosis factor-α (TNF-α). We conducted NIH-3T3 cell stimulation assay to evaluate the relation between HGF and protease activity in excretion/secretion (ES) derived from maggots. Compared with the control group, HGF was significantly higher in the 0.05 μg/ml ES group (P < 0.01). Furthermore, protease inhibitors suppressed the increase of HGF (P < 0.05). The HGF expression was increased in proportion to the ES protein concentration of 0.025 to 0.5 μg/ml. In fact, ES showed stronger capability of promoting HGF production and less cytotoxicity than chymotrypsin or bromelain. HGF is an important factor involved in cutaneous wound healing. Therefore, these results suggest that formation of healthy granulation tissue observed during MDT results from the increased HGF. Further investigation to identify molecules enhancing HGF expression by MDT will contribute greatly to drug target discovery for intractable wound healing therapy.