Despite almost universal implementation of reno-protective therapies over the last 25 years, risk of ESRD in type 1 diabetes (T1D) is not decreasing, and ESRD remains the major cause of excess morbidity and premature mortality . Such a state of affairs prompts a call to action. In this review we re-evaluated the proteinuria-centric model of diabetic nephropathy and showed its deficiencies. On the basis of the extensive studies that we have been conducting in the population of the Joslin Clinic, we propose that progressive renal decline, not abnormalities in urinary albumin excretion, should be considered as the major feature of disease processes leading to ESRD in T1D.
Etiology of diabetic nephropathy should be reconsidered in light of our new findings so our perspective can be broadened regarding new therapeutic targets available for interrupting the progressive renal decline in T1D. Reduction in the rate of GFR loss, not reduction of AER, should become the measure for evaluating the effectiveness of new therapeutic interventions. We need new accurate methods for early diagnosis of patients at risk of progressive renal decline or, better yet, for detecting in advance which patients will have rapid, moderate or minimal rate of progression to ESRD.
type 1 diabetes; kidney complications; Proteinuria; progressive renal decline
Traditional risk factors do not account for increased cardiovascular disease in patients with chronic kidney disease (CKD), particularly individuals whose CKD has progressed to end-stage kidney disease requiring dialysis. CKD patients on dialysis show little to no cardiovascular benefits from lipid-lowering therapy and thus have an exaggerated residual cardiovascular risk. High density lipoprotein (HDL) quantity and functionality may explain some of the residual risk. CKD affects the composition and disrupts the functionality of HDL, including cholesterol acceptor function and inflammatory effects. Notably, although these HDL abnormalities prevail in CKD, they do not track together and thereby support the idea of separate and distinct mechanistic pathways for each critical function of HDL. Targeting individual perturbations in HDL function represents a novel approach to therapy in this population.
HDL; Chronic Kidney Disease
Recent studies have identified genetic variants in APOL1 that may contribute to the increased incidence of kidney disease in populations with African ancestry. Herein, we review the biology of APOL1 present in the circulation and localized to the kidney as it may contribute to the pathogenesis of APOL1 associated kidney disease.
Genetics; apolipoprotein; HDL; APOL1; kidney; focal segmental glomerulosclerosis; HIV; HIV associated neprhopathy; hypertensive nephrosclerosis; chronic kidney disease
Water excretion is regulated in large part through the regulation of the osmotic water permeability of the renal collecting duct epithelium. The water permeability is controlled by vasopressin through regulation of the water channel, aquaporin-2 (AQP2). Two processes contribute: 1) regulation of AQP2 trafficking to the apical plasma membrane; and 2) regulation of the total amount of the AQP2 protein in the cells. Regulation of AQP2 abundance is defective in several water balance disorders including many polyuric disorders and the syndrome of inappropriate antidiuresis (SIADH). Here we review vasopressin signaling in the renal collecting duct that is relevant to the two modes of water permeability regulation.
Vasopressin; trafficking; transcription; polyuria; hyponatremia; SIADH
The nomenclature and classification of vasculitis has been difficult and controversial for many decades. This is problematic for both research on vasculitis as well as clinical care of patients with vasculitis. The first (1994) International Chapel Hill Consensus Conference on the Nomenclature of Systemic Vasculitides (CHCC) proposed names and definitions for the most common forms of vasculitis. Since then, there have been substantial advances in our understanding of vasculitis and changes in medical terminology. In addition, CHCC 1994 did not propose a nomenclature for some relatively common forms of vasculitis, such as vasculitis secondary to other diseases. To address these issues, a second International Chapel Hill Consensus Conference was held in 2012. The goals were to change names and definitions as appropriate, and add important categories of vasculitis not included in CHCC 1994. This overview summarizes the 2012 CHCC and points out the changes compared to the 1994 CHCC. Notable changes include the introduction of new terms such as granulomatosis with polyangiitis, eosinophilic granulomatosis with polyangiitis and IgA vasculitis, and the inclusion of categories for variable vessel vasculitis and secondary forms of vasculitis.
Vasculitis; classification; Chapel Hill Consensus Conference
Combination drugs containing an angiotensin receptor blocker and a calcium channel blocker have been widely commercialized in recent years, and their advantages, such as improvements in adherence, and reductions in medication costs, have been greatly emphasized. However, the actual situations and the impact of switching to combination drugs in clinical practice of nephrology are not fully understood.
This study was conducted in outpatients of nephrology who received antihypertensive medicines, and who switched to combination drugs. Changes in the potency of the antihypertensive drugs, and blood pressure were examined retrospectively before and after changing treatments. In addition, the study also involved patients’ questionnaire, which examined changes in blood pressure at home, the presence or absence of missed doses, the impact on medication-related expenses, and the level of patients’ satisfaction with regard to combination drugs.
Survey results from 90 participants revealed that changing to combination drugs resulted in a reduction of missed doses, a decrease in blood pressure measured in an outpatient setting, and a reduction in medication-related expenses in total patients, non-chronic kidney disease (CKD) patients, and CKD patients.
Our study shows that switching to combination antihypertensive drugs resulted in an improvement in adherence and a reduction in medication-related expenses, and revealed that patient satisfaction was high. Combination drugs for hypertensive patients may be beneficial in both medical and economical viewpoints.
Angiotensin receptor blockers; Calcium channel blockers; Combination antihypertensive drugs; Hypertension; Blood pressure
The tissue-protective effects of erythropoietin (EPO) have been extensively investigated, and EPO administration can raise the hemoglobin (Hb) concentration. Recently, we reported that carbamylated erythropoietin (CEPO) protected kidneys from ischemia-reperfusion injury as well as EPO.
To investigate the clinical applications of CEPO, we next evaluated the long-term therapeutic effect of CEPO using a tubulointerstitial model rat. We randomized remnant kidney model rats to receive saline, EPO, or CEPO for 8 weeks.
CEPO- and EPO-treated rats had improved serum creatinine levels compared with saline-treated remnant kidney model rats, although the Hb level was significantly increased in EPO-treated rats. Two-photon microscopy revealed that EPO/CEPO significantly ameliorated tubular epithelial cell damage assessed by endocytosis. In addition, CEPO or EPO protected endothelial cells with a sustained blood flow rate. EPO or CEPO suppressed the number of TUNEL-positive apoptotic cells with weak αSMA staining.
Furthermore, PCR analysis demonstrated that TGF-β and type I collagen expression was attenuated in EPO- or CEPO-treated rats, accompanied by a significant decrease in interstitial fibrosis.
We established a long-term therapeutic approach to protect tubulointerstitial injury with CEPO, and thus, the therapeutic value of this approach warrants further attention and preclinical studies.
Carbamylated erythropoietin; Remnant kidney; Apoptosis; TGF-β
Cardiovascular disease is the leading cause of morbidity and mortality in patients with kidney failure. Nocturnal home hemodialysis (NHD) is a form of kidney replacement therapy whereby hemodialysis is performed for at least 6-h overnight, at least 4 days per week. Little is known about the effects of NHD on cardiovascular remodeling as assessed by transthoracic echocardiography (TTE) and cardiac magnetic resonance imaging (CMR).
The primary objective of the study was to determine the long-term effects of NHD on cardiovascular remodeling using different imaging modalities over a one-year follow-up.
Methods and results
A total of 11 patients were included in the study (6 males, mean age 48 ± 16 years) between 2009 and 2011 inclusive at a single tertiary care center. All patients underwent TTE and CMR at baseline and after 1 year of NHD. Left ventricular mass index decreased significantly at 1 year by both TTE (152 ± 7–129 ± 8 g/m2, p < 0.05) and CMR (162 ± 4–124 ± 4 g/m2, p < 0.05). There was also a significant decrease in both left and right atrial volume as well as in right ventricular mass index over 1 year of follow-up. Diastolic dysfunction, graded from 0 to 4, improved from a baseline grade of 3.4 to 1.2 at 1-year follow-up.
Long-term nocturnal hemodialysis leads to favorable cardiovascular remodeling with a reduction in cavity dimensions, regression of left ventricular hypertrophy, and an improvement in diastolic function, as assessed by both TTE and CMR.
Home hemodialysis; High dose hemodialysis; Left ventricular hypertrophy; Cardiac imaging
Cyclosporine and prednisolone combination therapy has been used in the treatment of minimal change nephrotic syndrome (MCNS). However, few studies have evaluated the efficacy of cyclosporine combined with intravenous methylprednisolone pulse therapy (MPT) as a first-line treatment for new-onset MCNS. We conducted a retrospective clinical study to evaluate the efficacy and safety of cyclosporine combined with MPT and oral prednisolone for new-onset MCNS in adults.
Forty-six adult patients with biopsy-proven MCNS were analyzed retrospectively. This study included three groups. Group 1 (n = 17) was treated with intravenous MPT (0.5 or 1.0 g/day for 3 days) followed by oral cyclosporine (2–3 mg/kg/day) and prednisolone (30 mg/day). Group 2 (n = 15) was treated with intravenous MPT followed by oral prednisolone (0.4–0.8 mg/kg/day). Group 3 (n = 14) was treated with oral prednisolone (0.6–1.0 mg/kg/day) alone.
The length of hospital stay was the shortest in Group 1 (P < 0.001). The mean duration to achieve <20 mg/day of prednisolone was also the shortest in Group 1 (P < 0.05). Complete remission rates were 100 % in Group 1, 85.7 % in Group 2, and 69.2 % in Group 3 during the 9-month follow-up (P = 0.073). The rate of adverse effects caused by prednisolone was less in Group 1 (P < 0.05). Multivariate analysis revealed that the independent determinants of durations of remission were the selectivity index (P = 0.004), eGFR (P = 0.001) and the use of cyclosporine (P = 0.045).
Combination therapy with cyclosporine may be a beneficial treatment option for new-onset MCNS in adults because of its clinical efficacy and safety.
Cyclosporine; Minimal change nephrotic syndrome; Prednisolone; Clinical efficacy; Drug nephrotoxicity
Catabolic conditions including chronic kidney disease (CKD), cancer, and diabetes cause muscle atrophy. The loss of muscle mass worsens the burden of disease because it is associated with increased morbidity and mortality. To avoid these problems or to develop treatment strategies, the mechanisms leading to muscle wasting must be identified. Specific mechanisms uncovered in CKD generally occur in other catabolic conditions. These include stimulation of protein degradation in muscle arising from activation of caspase-3 and the ubiquitin-proteasome system (UPS). These proteases act in a coordinated fashion with caspase-3 initially cleaving the complex structure of proteins in muscle yielding fragments that are substrates which are degraded by the UPS. Fortunately, the UPS exhibits remarkable specificity for proteins to be degraded because it is the major intracellular proteolytic system. Without a high level of specificity cellular functions would be disrupted. The specificity is accomplished by complex reactions that depend on recognition of a protein substrate by specific E3 ubiquitin ligases. In muscle, the specific ligases are Atrogin-1 and MuRF1 and their expression has characteristics of a biomarker of accelerated muscle proteolysis. Specific complications of CKD (metabolic acidosis, insulin resistance, inflammation, and angiotensin II) activate caspase-3 and the UPS through mechanisms that include glucocorticoids and impaired insulin or IGF-1 signaling. Mediators activate myostatin which functions as a negative growth factor in muscle. In models of cancer or CKD, strategies that block myostatin prevent muscle wasting suggesting that therapies which block myostatin could prevent muscle wasting in catabolic conditions.
ubiquitin-proteasome system (UPS); muscle wasting; protein degradation; chronic kidney disease (CKD); caspase-3
High prevalence of masked hypertension as well as persistent hypertension was observed in the Chronic Kidney Disease Japan Cohort (CKD-JAC) study. We proposed a novel indicator of blood pressure (BP) load, hyperbaric area index (HBI), calculated from ambulatory blood pressure monitoring (ABPM) data. The characteristic of this index and its relationship with kidney function were also evaluated.
The CKD-JAC study, enrolled 2,977 patients, is a prospective observational study started in September 2007. ABPM was conducted in a sub-group from September 2007 to April 2010 and baseline ABPM data of 1,075 subjects (63.4 % male, 60.7 years old) were analyzed.
Mean systolic HBI of male and female patients were 242.3 and 176.5 mmHg×h, respectively. HBI sensitively reflected sex (54.7 mmHg×h higher in males than in females), seasonal effects (51.6 mmHg×h higher in winter than in summer), and advancing CKD stage [(16.5 mmHg×h higher) per −10 mL/min/1.73 m2 in eGFR]. The HBI was a significant factor to associate with reduced kidney function, after adjusting with nocturnal BP change (NBPC), sex, and other variables (p value <0.001).
Our findings suggested that HBI might be a novel sensitive indicator for the reduction of kidney function, independent of patterns of NBPC.
Chronic kidney disease; Hypertension; Hyperbaric area index; Ambulatory blood pressure monitoring (ABPM); Blood pressure load
LDL-apheresis is a method to correct dyslipidemia rapidly. It is expected to alleviate the tissue toxicity of persistent dyslipidemia in not only primary, but also in secondary dyslipidemia associated with refractory nephrotic syndrome, and to have a protective effect against glomerular and tubular injury as expected in atherosclerosis. In addition, the effectiveness of LDL-apheresis to promote the remission of nephrotic syndrome has been recognized. In Japan, LDL-A to control hyperlipidemia in patients with refractory nephrotic syndrome associated with focal segmental glomerulosclerosis is covered by national health insurance. Here, the hypothetical mechanism behind its effect and the evidence for its effectiveness over a long period are reviewed.
LDL-apheresis; Nephrotic syndrome; Secondary hyperlipidemia; Lipid nephrotoxicity; Cohort study
Among the proteinuric patients with chronic kidney disease (CKD) who undergo a renal biopsy, we sometimes encounter those who cannot be classified as having a known primary or secondary glomerular disease. The pathogenesis and pathophysiology of these CKD patients have not been sufficiently elucidated.
We recruited 34 proteinuric patients without known glomerular diseases. The glomerular volumes (GV) of the biopsy specimens from those patients were determined by a morphometric analysis. Glomerular hypertrophy (GH) was defined as having more than 3.6 × 106 μm3. The patients were divided in two groups: those with GH (Group 1) and those without GH (Group 2). We compared the clinical and pathological parameters between Group 1 and Group 2, and among the three groups of patients: non-obese, overweight and obese group.
The patients with Group 1 had significantly higher values for the proportion of males, the body mass index (BMI), uric acid and significantly lower values for the glomerular density (GD). Of note, a multivariate regression analysis revealed that sex, the BMI and GD were significant factors correlated with the mean GV. The values for the mean GV were significantly higher in the overweight and obese groups as compared to the non-obese group, and the values for the GD were significantly lower in the obese group than in the non-obese group.
We identified a subgroup of patients who were characterized as having a high BMI and GV, and a low GD among the proteinuric CKD patients without known glomerular diseases.
Chronic kidney disease; Glomerular hypertrophy; Proteinuria; Overweight; Obesity; Body mass index; Renal biopsy; Glomerular density
Our recently published cost-effectiveness study on chronic kidney disease mass screening test in Japan evaluated the use of dipstick test, serum creatinine (Cr) assay or both in specific health checkup (SHC). Mandating the use of serum Cr assay additionally, or the continuation of current policy mandating dipstick test only was found cost-effective. This study aims to examine the affordability of previously suggested reforms.
Budget impact analysis was conducted assuming the economic model would be good for 15 years and applying a population projection. Costs expended by social insurers without discounting were counted as budgets.
Annual budget impacts of mass screening compared with do-nothing scenario were calculated as ¥79–¥−1,067 million for dipstick test only, ¥2,505–¥9,235 million for serum Cr assay only and ¥2,517–¥9,251 million for the use of both during a 15-year period. Annual budget impacts associated with the reforms were calculated as ¥975–¥4,129 million for mandating serum Cr assay in addition to the currently used mandatory dipstick test, and ¥963–¥4,113 million for mandating serum Cr assay only and abandoning dipstick test.
Estimated values associated with the reform from ¥963–¥4,129 million per year over 15 years are considerable amounts of money under limited resources. The most impressive finding of this study is the decreasing additional expenditures in dipstick test only scenario. This suggests that current policy which mandates dipstick test only would contain medical care expenditure.
CKD; Budget impact; Dipstick test; Mass screening; Proteinuria; Serum creatinine assay
The primary abnormal manifestation in immunoglobulin A nephropathy (IgAN) is recurring bouts of hematuria with or without proteinuria. Although immunohistochemical analysis of renal biopsy tissue remains the gold standard not only for diagnosis but also for evaluating the activity of IgAN, new sensitive and reasonably specific noninvasive tests are emerging to guide therapeutic strategy applicable to all stages of IgAN. The present study examined serum levels of galactose-deficient IgA1 (Gd-IgA1) and its immune complex (IgA/IgG-IC) as noninvasive markers for the disease activity.
We enrolled 50 IgAN patients (male 40 %, median age 37 years) showing complete or partial clinical remission after steroid pulse therapy with tonsillectomy (TSP) whose clinical data and serum could be followed up for 3–5 years.
Cross-sectional analysis revealed that the degree of hematuria and proteinuria were significantly associated with levels of Gd-IgA1 and levels of IgA/IgG-IC. Longitudinal analysis further showed that from the group of 44 patients with heavy hematuria before TSP, 31 patients showed complete disappearance of hematuria (group A), but the remaining patients did not (group B). Although the levels of Gd-IgA1 and IgA/IgG-IC in the two groups before TSP were similar, percentage decrease of Gd-IgA1 and IgA/IgG-IC levels in group A was significantly higher than in group B.
Disease activity of IgAN assessed by hematuria and proteinuria correlated with serum levels and changes of Gd-IgA1 and IgA/IgG-IC. These new noninvasive disease activity markers can be useful for future activity scoring system and guiding therapeutic approaches.
IgA nephropathy; Disease activity; Underglycosylated IgA; Immune complex; Biomarker
Topiroxostat, a selective xanthine oxidase inhibitor, shows effective reduction in the serum urate level in hyperuricemic patients with or without gout. The objective of this study was to evaluate the efficacy and safety of topiroxostat in hyperuricemic stage 3 chronic kidney disease patients with or without gout.
The study design was a 22-week, randomized, multicenter, double-blind study. The enrolled patients were randomly assigned to treatment with topiroxostat 160 mg/day (n = 62) or to the placebo (n = 61). The endpoints were the percent change in the serum urate level, change in the estimated glomerular filtration rate, the urinary albumin-to-creatinine ratio, the proportion of patients with serum urate levels of 356.88 μmol/L or less, blood pressure, and serum adiponectin.
After 22 weeks, although the changes in the estimated glomerular filtration rate and blood pressure were not significant, the percent change in the serum urate level (−45.38 vs. −0.08 %, P < 0.0001) and the percent change in urinary albumin-to-creatinine ratio (−33.0 vs. −6.0 %, P = 0.0092) were found to have decreased in the topiroxostat as compared with the placebo. Although the incidence of ‘alanine aminotransferase increased’ was higher in the topiroxostat, serious adverse event rates were similar in the two groups.
Topiroxostat 160 mg effectively reduced the serum urate level in the hyperuricemic stage 3 chronic kidney disease patients with or without gout.
Hyperuricemia; Gout; CKD; Topiroxostat; FYX-051
Umbilical hernia; Autosomal dominant polycystic kidney disease
Combined treatment with cyclosporine microemulsion preconcentrate (CyA MEPC) and steroids has been widely used for idiopathic membranous nephropathy (IMN) associated with steroid-resistant nephrotic syndrome (SRNS). Recent studies have shown that once-a-day and preprandial administration of CyA MEPC is more advantageous than the conventional twice-a-day administration in achieving the target blood CyA concentration at 2 h post dose (C2). We designed a randomized trial to compare these administrations.
IMN patients with SRNS (age 16–75 years) were divided prospectively and randomly into 2 groups. In group 1 (n = 23), 2–3 mg/kg body weight (BW) CyA MEPC was given orally once a day before breakfast. In group 2 (n = 25), 1.5 mg/kg BW CyA MEPC was given twice a day before meals. CyA + prednisolone was continued for 48 weeks.
Group 1 showed a significantly higher cumulative complete remission (CR) rate (p = 0.0282), but not when incomplete remission 1 (ICR1; urine protein 0.3–1.0 g/day) was added (p = 0.314). Because a C2 of 600 ng/mL was determined as the best cut-off point, groups 1 and 2 were further divided into subgroups A (C2 ≥600 ng/mL) and B (C2 <600 ng/mL). Groups 1A and 2A revealed significantly higher cumulative remission (CR + ICR1) (p = 0.0069) and CR-alone (p = 0.0028) rates. On the other hand, 3 patients with high CyA levels (C2 >900 ng/mL) in Group 1A were withdrawn from the study because of complications.
CyA + prednisolone treatment is effective for IMN with associated SRNS at a C2 of ≥600 ng/mL. To achieve remission, preprandial once-a-day administration of CyA at 2–3 mg/kg BW may be the most appropriate option. However, we should adjust the dosage of CyA by therapeutic drug monitoring to avoid complications.
Cyclosporine; Idiopathic membranous nephropathy; Steroid-resistant nephrotic syndrome; Once-a-day administration; Preprandial administration; Therapeutic drug monitoring
Dyslipidemia is an independent risk factor for the development and progression of diabetic nephropathy (DN). In this review, we summarize mouse models with both diabetes and dyslipidemia, and their associated complications. We then discuss molecules potentially involved in deterioration of DN by dyslipidemia. We focus especially upon toll-like receptor 4 (TLR4) and one of its endogenous ligands, myeloid-related protein 8 (MRP8 or S100A8), since we have found that their mRNA levels are commonly increased in glomeruli of type 1 (streptozotocin [STZ]-induced) and type 2 (A-ZIP/F-1 lipoatrophic) diabetic mice. Gene expression of MRP8 and Tlr4 is further upregulated during worsening of STZ-induced DN by a high fat diet (HFD). Moreover, these HFD-induced changes are accompanied by enhanced gene expression of CCAAT element binding protein β and phosphorylation of c-Jun N-terminal kinase in the kidney, which have also been reported in pancreatic β cells under diabetic-hyperlipidemic conditions. Effects of a HFD upon DN are cancelled in Tlr4 knockout mice. Macrophages are the predominant source of MRP8 in glomeruli. In cultured macrophages, combinatorial treatment with high glucose and palmitate amplifies MRP8 expression in a Tlr4-dependent manner, and recombinant MRP8 protein markedly increases gene expression of the inflammatory cytokines interleukin-1β and tumor necrosis factor α. Here, we propose ‘macrophage-mediated glucolipotoxicity’ via activation of MRP8/TLR4 signaling as a novel mechanism of pathophysiology for DN.
Diabetic nephropathy; Glucolipotoxicity; Macrophage; Toll-like receptor
In Japan, the Research Committee on Intractable Vasculitides, supported by the Ministry of Health, Labour and Welfare, has been promoting basic and clinical research on vasculitis since 1972. The present Research Committee on Intractable Vasculitides comprises 4 subcommittees under the direction of a Principal Investigator: Basic and Pathological Research Subcommittee, Clinical Research Subcommittee of Small and Medium-sized Vessel Vasculitis, Clinical Research Subcommittee of Large-sized Vessel Vasculitis, and International Cooperation Research Subcommittee. Since 2008, 9 nationwide clinical studies for vasculitis have been conducted and 8 clinical and basic studies are in progress.
Antineutrophil cytoplasmic antibody-associated vasculitis; Eosinophilic granulomatosis with polyangiitis; Granulomatosis with polyangiitis; Microscopic polyangiitis
This retrospective study was designed to estimate the clinical remission (CR) rate of tonsillectomy plus steroid pulse (TSP) therapy in patients with IgA nephropathy.
Based on 292 of 302 patients with IgA nephropathy treated at 11 Japanese hospitals, we constructed heat maps of the CR rate at 1 year after TSP with the estimated glomerular filtration rate (eGFR), grade of hematuria, pathological grade, number of years from diagnosis until TSP, and age at diagnosis on the vertical axis and the daily amount of urinary protein (urinary protein) on the horizontal axis. We compared subgroups usinge Student’s t test, the chi-square test with Yates correction, or Fisher’s exact probability test.
The first heat map of eGFR and urinary protein showed that the CR rate was 71 % (CR vs. non-CR, 96 vs. 40) in patients with eGFR greater than 30 ml/min/1.73 m2 and 0.3–1.09 g/day of urinary protein. However, the CR rate in patients with more than 1.50 g/day of urinary protein was approximately 30 %. The second heat map of grade of hematuria and urinary protein revealed that the CR rate is 72 % (CR vs. non-CR, 93 vs. 37) in patients with more than 1+ hematuria and 0.3–1.09 g/day of urinary protein; however, it was 28.6 % in patients with no hematuria. The third heat map of pathological grade and urinary protein demonstrated that the highest CR rate was 83 % (CR vs. non-CR, 52 vs. 11) in patients with pathological grade I or II disease and less than 1.09 g/day of urinary protein, as opposed to 22 % (CR vs. non-CR, 9 vs. 32) in patients with pathological grade III or IV disease and more than 2.0 g/day of urinary protein. The fourth heat map of the number of years from diagnosis until TSP and urinary protein revealed that the former did not influence the CR rate in patients with less than 1.09 g/day of urinary protein. However, in patients with more than 1.10 g/day of urinary protein, the CR rate of the subgroup with less than 6 years was 43 % (CR vs. non-CR; 23 vs. 54) compared to 23 % (CR vs. non-CR, 11 vs. 48; P = 0.01) in the subgroup with more than 6 years. The fifth heat map of age at diagnosis and urinary protein showed that the CR rate is approximately 72 % (CR vs. non-CR, 73 vs. 28) in patients older than 19 years at diagnosis with 0.3–1.09 g/day of urinary protein.
The daily amount of urinary protein is an important predictor of the CR rate after TSP in IgA nephropathy patients. Heat maps are useful tools for predicting the CR rate associated with TSP.
Clinical remission; Heat map; IgA nephropathy; Tonsillectomy plus steroid pulse therapy
Because oral nonsteroidal anti-inflammatory drugs (NSAIDs) have adverse effects on kidney function, patients with kidney diseases are administered these drugs as transdermal patches. Little is known about the effects of NSAID patches on renal function. We therefore assessed the effects of topical loxoprofen sodium on kidney function in type 2 diabetic patients with overt nephropathy.
Twenty patients with type 2 diabetes and overt proteinuria and with knee and/or low back pain were treated with skin patches containing 100 mg loxoprofen on the knee or back for 24 h per day for 5 consecutive days. The degree of pain was assessed using a visual analogue scale (VAS). Blood and 24-h urine samples were obtained at baseline and at the end of the study. Glomerular filtration rate (GFR) was estimated from serum creatinine and cystatin C concentrations.
The 20 patients consisted of 11 males and 9 females, of mean age 61.6 ± 13.9 years. Loxoprofen-containing patches significantly reduced VAS pain without affecting blood pressure, GFR or urinary prostaglandin E2 concentration. Serum concentrations of loxoprofen and its active trans-OH metabolite did not correlate with GFR.
Loxoprofen-containing patches do not affect renal function in type 2 diabetic patients with overt nephropathy over a short-term period. Long-term studies are needed to clarify the safety of loxoprofen-containing patches in patients with chronic kidney diseases.
Skin patches; Loxoprofen; Diabetic nephropathy; Type 2 diabetes; Prostaglandin E2; GFR; NSAIDs
The significance of total kidney volume (TKV) as a biomarker of kidney function in autosomal dominant polycystic kidney disease (ADPKD) is controversial and has been reappraised.
Between 2007 and 2012, 64 patients were followed with a mean 39.7-month observation period. TKV measurements by magnetic resonance imaging and estimation of renal function with estimated glomerular filtration rate (eGFR) using the Modification of Diet in Renal Disease equation and 24-h urine creatinine clearance were repeated annually.
TKV and its adjusted parameters (height-adjusted, body surface area-adjusted and log-converted TKV [log-TKV]) correlated with eGFR significantly. Among them, the correlation coefficient of log-TKV was most significant (r = −0.6688, p < 0.001). The eGFR slope correlated negatively with TKV slope (p < 0.05). TKV increased faster and became larger as chronic kidney disease (CKD) stage advanced. As age advanced, eGFR declined significantly (p < 0.001), but the eGFR slope remained constant. There was no significant correlation between TKV and age, but the log-TKV slope became smaller as age advanced. If baseline TKV was large, the eGFR slope was steeper (p < 0.05), which suggests that eGFR declines faster in patients with larger kidney volume.
TKV is confirmed as a clinically meaningful surrogate marker in ADPKD. Log-TKV correlates with eGFR most significantly. Higher rates of kidney enlargement and larger kidney volume are associated with a more rapid decrease in kidney function. Kidney function decreased faster as CKD stage advanced, but its declining slope did not change significantly by age, at least after ~30 years of age.
Autosomal dominant polycystic kidney disease; Glomerular filtration rate; Kidney volume
Previous studies on membranoproliferative glomerulonephritis (MPGN) and cryoglobulinemic glomerulopathy (CG) were based upon case series that were performed before hepatitis C virus (HCV) infection was routinely investigated. Therefore, it remains unknown how far HCV contributes to MPGN or CG, and there have only been a few reports about HCV-negative idiopathic MPGN.
Patients and methods
Thirty-five patients with MPGN diagnosed by renal biopsy who underwent examination for HCV infection at our institute between 1990 and 2008 were recruited for this study. Patients with HCV infection at presentation were included, but patients with complications such as underlying lymphoproliferative disorders, autoimmune diseases like lupus nephritis, infection, and liver disease due to hepatitis B virus or alcohol abuse were excluded. A total of 35 patients were enrolled and they were divided into two groups according to the presence/absence of circulating cryoglobulins (cryo). The 23 patients who had cryo-negative and HCV-negative idiopathic MPGN were divided into subgroups with type 1 and type 3 disease.
In the cryo-positive group (n = 9), 7 patients were positive for HCV infection, while 2 patients were negative. In the cryo-negative group (n = 26), 3 patients were positive for HCV infection, while 23 patients were negative (idiopathic MPGN). Compared with the cryo-negative group, the cryo-positive group had several characteristics such as more severe thrombocytopenia, higher serum immunoglobulin (Ig)G and IgM levels, lower levels of hemolytic complement (CH50) and complement component (C)4, predominant IgM staining, and type 1 histology. Patients with cryo-negative and HCV-negative ‘idiopathic’ MPGN showed predominant staining for IgG in both type 1 and type 3 cases, unlike the predominant staining for IgM in the cryo-positive group. Compared with type 3 cases, type 1 cases had a younger age, lower levels of CH50, C3 and C4, and less proteinuria. In the cryo-positive group, 4 patients (44.4 %) died, with death from B cell lymphoma and liver failure in 2 patients each, while 1 patient (8 %) developed end-stage renal failure requiring dialysis. In contrast, all patients in the cryo-negative group remained alive during follow-up, although 4 patients (2 type 1 cases and 2 type 3 cases) required dialysis.
Cryo-positive MPGN shows a close relationship with HCV infection and IgM, resulting in a poor prognosis. Cryo-negative and HCV-negative idiopathic MPGN has a close relationship with IgG staining, and type 1 cases feature characteristics such as a younger age, more severe hypocomplementemia, and less proteinuria than in type 3 cases.
Membranoproliferative glomerulonephritis; Type 1 and type 3; Type 2; Cryoglobulin; Cryoglobulinemic glomerulopathy
The epidemiology of systemic vasculitides differs between Japan, Europe and North America. Takayasu’s arteritis occurs frequently in Japan, unlike giant cell arteritis. A collaborative international study comparing the epidemiology of anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis between Japan and the United Kingdom (UK) demonstrated that microscopic polyangiitis and myeloperoxidase-ANCA were more common in Japan whereas granulomatosis with polyangiitis and pronase 3-ANCA were more common in the UK. These differences may be attributed to differences in latitude and genetic backgounds. These findings provide useful information on the aetiology and pathogenesis of primary systemic vasculitides in various geographical regions.
Microscopic polyangiitis; Granulomatosis with polyangiitis; Takayasu’s arteritis; Giant cell arteritis; Rapidly progressive glomerulonephritis; HLA-DRB1*09:01