坪井 直毅

Objective. The diagnostic values of antiproteinase 3 and antimyeloperoxidase tests using antineutrophil cytoplasmic antibodies (ANCA) are well established. Our study determined whether an increase in ANCA level was a predictor of disease flareup. Methods. Our study included 126 patients with ANCA-associated renal vasculitis treated at 9 nephrology centers in Japan. The relationship between increased ANCA levels and relapse was assessed using time-dependent multivariate Cox regression models adjusted for clinically relevant factors. The outcome of interest was the time from remission to first relapse. Results. During the observation period [median 41 mos, interquartile range (IQR) 23-66 mos], 118 patients (95.8%) achieved remission at least once. After achieving remission, 34 patients relapsed (21.7%). Time-dependent multivariate Cox regression models revealed that lung involvement (adjusted HR 2.29, 95% CI 1.13-4.65, p = 0.022) and increased ANCA levels (adjusted HR 17.4, 95% CI 8.42-36.0, p < 0.001) were significantly associated with relapse. The median time from ANCA level increase to relapse was 0.6 months (IQR 0-2.1 mos). Conclusion. In our study, an increase in ANCA level during remission was associated with a risk of disease relapse. A rise in ANCA level may be useful for guiding treatment decisions in appropriate subsets of patients with ANCA-associated vasculitis.

Previous studies have suggested that high neutrophil/lymphocyte ratios are related to worse outcome in patients with cardiovascular diseases. Patients with end-stage renal disease, especially those with inflammation, are at an increased risk of premature mortality, primarily because of cardiovascular disease. We aimed to clarify if high neutrophil/lymphocyte ratio is associated with increasing cardiovascular events in Japanese patients with end-stage renal disease. We enrolled 86 incident Japanese dialysis patients (58 men, age 58 +/- A 11 years) in a prospective cohort study. The median follow-up was for 38.7 months. The association between neutrophil/lymphocyte ratio at the start of dialysis therapy and clinical biomarkers was investigated. Relative risks and cumulative cardiovascular disease events were calculated. The median neutrophil/lymphocyte ratio reported was 3.72. The duration from the start of the dialysis therapy to the first cardiovascular disease event was significantly shorter as a neutrophil/lymphocyte ratio increased (log-rank test, P = 0.003). The relative risk of cardiovascular disease events in patients with neutrophil/lymphocyte ratio > median to cardiovascular events in patients with the ratio < median as a reference was 3.02 (95 % CI 1.32-8.00) in a Cox proportional hazard model. The cumulative cardiovascular disease events during the observational period was higher in patients with neutrophil/lymphocyte ratio > median (23.0 events 100 person-years) than in patients with the ratio < median (6.8 events 100 person-years). A higher neutrophil/lymphocyte ratio is associated with increased risk of cardiovascular disease events and is a stronger predictor of future events.

Objective Presepsin is highlighted as a diagnostic and prognostic marker of sepsis. Little information is available regarding the accurate association between presepsin levels and the degree of kidney function. We analyzed presepsin levels in patients with a glomerular filtration rate (GFR) in the categories G1 to G5, evaluated via inulin renal clearance test, and receiving hemodialysis (HD). Methods Patients who were not receiving HD were included if they had undergone inulin renal clearance measurements for the accurate measurement of GFR (measured GFR), and patients who were receiving hemodialysis (HD) were included if they had anuria. Exclusion criteria were infection, cancer, liver disease, autoimmune disorders, or steroid or immunosuppressant use. GFR category was defined as follows; G1: GFR >= 90 ml/min/1.73m(2), G2: GFR = 60 to 90 ml/min/1.73m(2), G3: GFR = 30 to 60 ml/min/1.73m(2), G4: GFR = 15 to 30 ml/min/1.73m(2), G5: GFR <= 15 ml/min/1.73m(2). Results Seventy-one patients were included. The median (IQR) presepsin values of patients in each GFR category were as follows: G1 + G2: 69.8 (60.8-85.9) pg/ml; G3: 107.0 (68.7-150.0) pg/ml; G4: 171.0 (117.0-200.0) pg/ml; G5: 251.0 (213.0-297.5) pg/ml; and HD: 1160.0 (1070.0-1400.0) pg/ml. The log-transformed presepsin values, excluding patients receiving HD, inversely correlated with the measured GFR (Pearson's correlation coefficient = -0.687, P < 0.001). The multivariate analysis revealed that measured GFR and hemoglobin levels significantly correlated with elevated presepsin levels. Conclusion Presepsin levels were markedly high in patients receiving HD, similar to values seen in patients with severe sepsis or septic shock. In patients who were not receiving HD, presepsin levels increased as GFR decreased. Thus, the evaluation of presepsin levels in patients with chronic kidney disease requires further consideration, and a different cutoff value is needed for diagnosing sepsis in such patients.

Background Tolvaptan selectively binds to the vasopressin V2 receptor and inhibits reabsorption of free water. Although its efficacy for heart failure has been proven, its efficacy for chronic kidney disease (CKD) patients has not been assessed in detail. Methods We examined 20 CKD patients (13 men and 7 women) who presented with volume overload and who were administered tolvaptan. We assessed urine volume (UV) and blood biochemistry before administration (d0), 1 day after administration (d1), and 7 to 14 days after administration (d7-14). Results The mean age was 74.0 +/- 13.1 years. Besides CKD, there were 9, 8, and 5 patients with heart failure, liver failure or liver cirrhosis, and severe oedema, respectively. UV significantly increased from 959.0 +/- 503.8 mL/day at d0 to 1605.4 +/- 964.0 mL/day at d7-14 (P < 0.01). Serum creatinine levels were not exacerbated (3.89 +/- 3.43 mg/dL at d0 and 3.66 +/- 3.02 mg/dL at d7-14). Serum albumin (ALB) levels and urinary protein creatinine ratio (uPCR) did not correlate with UV change. Estimated glomerular filtration rate (eGFR) correlated with UV change from d0 to d1 (r = 0.6619, P < 0.01). Serum sodium elevation correlated with increased UV (r = 0.4951, P < 0.05). Conclusion Tolvaptan is useful to reduce volume overload without exacerbation of the renal function; its effect does not depend on ALB or uPCR. The eGFR correlated with the efficacy of tolvaptan. If UV increases drastically after tolvaptan administration, serum Na levels should be carefully monitored.

Diffuse pulmonary hemorrhage (DPH) is an uncommon but critical complication of systemic lupus erythematosus. Peritoneal administration of 2,6,10,14-tetramethylpentadecane (pristane) can recapitulate a lupus-like syndrome in mice, which can develop into DPH within a few weeks, especially in C57BL/6 mice. Mac-1 (CD11b/CD18), a leukocyte adhesion molecule, is known to play a role in inflammation by regulating migration of leukocytes into injured tissue. In this study, we aimed to clarify the role of Mac-1 in pristane-induced DPH, using Mac-1(-/-) and wild-type (WT) mice on a C57BL/6 background. After pristane injection, Mac-1(-/-) mice showed reduced prevalence of DPH and attenuated peritonitis compared with WT mice. Analysis of the peritoneal lavage on days 5 and 10 after pristane treatment revealed increased numbers of eosinophils and alternatively activated macrophages, but decreased numbers of neutrophils and classically activated macrophages in Mac-1(-/-) mice compared with WT. Enhanced production of IL-4 and IL-13, both key mediators of macrophage polarization toward the mannose receptor(+) (MMR+) phenotype, was observed in the peritoneal cavity of Mac-1(-/-) mice. Depletion of neutrophils and eosinophils or adoptive transfer of classically activated macrophages resulted in the exacerbation of pristane-mediated DPH in both WT and Mac-1(-/-) mice. Moreover, peritoneal transfer of F4/80(high)MMR(+) alternatively activated macrophages successfully reduced the prevalence of DPH in WT mice. Collectively, Mac-1 promoted acute inflammatory responses in the peritoneal cavity and the lungs by downregulating granulocyte migration and subsequent phenotypic conversion of macrophages in a pristane-induced systemic lupus erythematosus model.

Background: Idiopathic membranous nephropathy (IMN) is increasingly seen in older patients. However, differences in disease presentation and outcomes between older and younger IMN patients remain controversial. We compared patient characteristics between younger and older IMN patients. Methods: We recruited 171 Japanese patients with IMN, including 90 (52.6%) patients <65 years old, 40 (23.4%) patients 65-70 years, and 41 (24.0%) patients >= 71 years. Clinical characteristics and outcomes were compared between younger and older IMN patients. Results: During a median observation period of 37 months, 103 (60.2%) patients achieved complete proteinuria remission, which was not significantly associated with patient age (P = 0.831). However, 13 (7.6%) patients were hospitalized because of infection. Multivariate Cox proportional hazards models identified older age [adjusted hazard ratio (HR) = 3.11, 95% confidence interval (CI): 1.45-7.49, per 10 years; P = 0.003], prednisolone use (adjusted HR = 11.8, 95% CI: 1.59-242.5; P = 0.014), and cyclosporine used in combination with prednisolone (adjusted HR = 10.3, 95% CI: 1.59-204.4; P = 0.012) as significant predictors of infection. A <25% decrease in proteinuria at 1 month after immunosuppressive therapy initiation also predicted infection (adjusted HR = 6.72, 95% CI: 1.51-37.8; P = 0.012). Conclusions: Younger and older IMN patients had similar renal outcomes. However, older patients were more likely to develop infection when using immunosuppressants. Patients with a poor response in the first month following the initiation of immunosuppressive therapy should be carefully monitored for infection and may require a faster prednisolone taper.

Background: Multiple studies have shown cigarette smoking to be a risk factor for chronic kidney disease. However, it is unknown whether smoking similarly increases the risk for progression of membranous nephropathy. Methods: This study used the Nagoya Nephrotic Syndrome Cohort Study (N-NSCS), including 171 patients with idiopathic membranous nephropathy (IMN) from 10 nephrology centers in Japan. The dose-response relationships between cigarette smoking and the outcomes were assessed by using multivariate Cox proportional hazards models adjusted for clinically relevant factors. The primary outcome was a 30% decline in the estimated glomerular filtration rate (eGFR). The secondary outcome was first complete remission (CR) of proteinuria. Results: During the observation period (median, 37 months; interquartile range, 16-71 months), 37 (21.6%) patients developed a 30% decline in eGFR and 2 (1.2%) progressed to ESRD. CR occurred in 103 (60.2%) patients. Multivariate Cox proportional hazards models revealed current smoking (adjusted hazard ratio [HR], 7.81 [95% confidence interval (CI), 3.17-19.7]), female sex (adjusted HR, 3.58 [95% CI, 1.87-8.00]), older age (adjusted HR, 1.71 [95% CI, 1.13-2.62] per 10 years), the number of cigarettes smoked daily (adjusted HR, 1.61 [95% CI, 1.23-2.09] per 10 cigarettes daily), and cumulative smoking of >= 40 pack-years (adjusted HR, 5.56 [95% CI, 2.17-14.6]) to be associated with a 30% decline in eGFR. However, smoking was not associated with CR. Conclusion: Smoking is a significant and dose-dependent risk factor for IMN progression. All patients with IMN who smoke should be encouraged to quit.

Objective: A glycosylated transmembrane protein, CD147, has been implicated in regulating lymphocyte responsiveness and leukocyte recruitment. As lupus nephritis (LN) often follows a relapsing-remitting disease course, accurate understanding of the disease activity would be extremely helpful in improving prognosis. Unfortunately, neither clinical nor serological data can accurately reflect the histological features of LN. The present study investigated whether CD147 can accurately predict pathological features of LN. Methods: Plasma and spot urine samples were collected from 64 patients who underwent renal biopsy between 2008 and 2011. Disease activity for LN tissues was evaluated using the biopsy activity index, and compared to levels of biomarkers including CD147. Results: In LN tissues, CD147 induction was striking in injured glomeruli and infiltrating inflammatory cells, but not in damaged tubules representing atrophy. Plasma CD147 levels accurately reflected the histological disease activity. However, prediction using a single molecule would be quite difficult because of the complex pathogenesis of LN. The diagnostic accuracy of multiplex parameters indicated that the combination including plasma CD147 might yield excellent diagnostic abilities for guiding ideal LN therapy. Conclusion: Plasma CD147 levels might offer useful insights into disease activity as a crucial biomarker in patients with LN.

Background aims. In patients receiving peritoneal dialysis, fungal or yeast peritonitis has a poor prognosis. In rat peritoneum with mechanical scraping, severe peritonitis can be induced by zymosan, a component of yeast (Zy/scraping peritonitis). Administration of rat adipose tissue-derived stromal cells (ASCs) potentially can improve several tissue injuries. The present study investigated whether rat ASCs could improve peritoneal inflammation in Zy/scraping peritonitis. Methods. Rat ASCs were injected intraperitoneally on a daily basis in rats with Zy/scraping peritonitis. Results. Peritoneal inflammation accompanied by accumulation of inflammatory cells and complement deposition was suppressed by day 5 after injection of rat ASCs. The peritoneal mesothelial layer in Zy/scraping peritonitis with rat ASC treatment was restored compared with the peritoneal mesothelial layer without rat ASC treatment. Injected rat ASCs co-existed with mesothelial cells in the sub-peritoneal layer. In vitro assays showed increased cellular proliferation of rat mesothelial cells combined with rat ASCs by co-culture assays, confirming that fluid factors from rat ASCs might play some role in facilitating the recovery of rat mesothelial cells. Hepatocyte growth factor was released from rat ASCs, and administration of recombinant hepatocyte growth factor increased rat mesothelial cell proliferation. Conclusions. Because the peritoneal mesothelium shows strong expression of membrane complement regulators such as Crry, CD55 and CD59, restoration of the mesothelial cell layer by rat ASCs might prevent deposition of complement activation products and ameliorate peritoneal injuries. This study suggests the therapeutic possibilities of intraperitoneal rat AS C injection to suppress peritoneal inflammation by restoring the mesothelial layer and decreasing complement activation in fungal or yeast peritonitis.

Mesenchymal stromal cells (MSCs) derived from adipose tissue have immunomodulatory effects, suggesting that they may have therapeutic potential for crescentic GN. Here, we systemically administered adipose-derived stromal cells (ASCs) in a rat model of anti-glomerular basement membrane (anti-GBM) disease and found that this treatment protected against renal injury and decreased proteinuria, crescent formation, and infiltration by glomerular leukocytes, including neutrophils, CD8(+) T cells, and CD68(+) macrophages. Interestingly, ASCs cultured under low-serum conditions (LASCs), but not bone marrow-derived MSCs (BM-MSCs), increased the number of innmunoregulatory CD163(+) macrophages in diseased glomeruli. Macrophages cocultured with ASCs, but not with BM-MSCs, adopted an immunoregulatory phenotype. Notably, LASCs polarized macrophages into CD163(+) immunoregulatory cells associated with IL-10 production more efficiently than ASCs cultured under high-serum conditions. Pharmaceutical ablation of PGE(2) production, blocking the EP4 receptor, or neutralizing IL-6 in the coculture medium all significantly reversed this LASC-induced conversion of macrophages. Furthermore, pretreating LASCs with aspirin or cyclooxygenase-2 inhibitors impaired the ability of LASCs to ameliorate nephritogenic IgG-mediated renal injury. Taken together, these results suggest that LASCs exert renoprotective effects in anti-GBM GN by promoting the phenotypic conversion of macrophages to immunoregulatory cells, suggesting that LASC transfer may represent a therapeutic strategy for crescentic GN. J Am Soc Nephrol 24: 587-603, 2013. doi: 10.1681/ASN.2012030264

Inflammatory cell infiltration and fibrin deposition play important roles in the development of crescentic glomerulonephritis (GN). In particular, activation of coagulation is an indispensable factor in crescent formation. However, the mechanisms underlying the pathogenesis of crescent formation have not been completely elucidated. We identified the growth factor midkine (MK) as a novel key molecule in the progression of crescentic GN induced by anti-glomerular basement membrane antibody. Despite the lack of significant differences in autologous and heterologous reactions, MK-deficient (Mdk -/-) mice unexpectedly showed a greater number of necrotizing glomerular injuries than wild-type (Mdk+/+) mice. Likewise, more tubulointerstitial damage was observed in Mdk-/- mice, and this damage positively correlated with glomerular injury. Plasminogen activator inhibitor (PAI)-1 was strongly induced in the injured glomerulus of Mdk -/- mice, particularly in crescents and endothelial cells. This enhanced PAI-1 production was associated with an increase in inflammatory cell infiltration and matrix deposition in the glomerulus and the interstitium of Mdk-/- mice. In line with these in vivo data, primary cultured endothelial cells derived from Mdk-/- mice exhibited higher PAI-1 mRNA expression on fibrin challenge and less fibrinolysis than Mdk+/+ mice. In contrast, the expression of plasminogen activators was not affected. Our combined data suggest that MK leads to a blockade of PAI-1, which is closely associated with the suppression of crescentic GN. © 2013 American Society for Investigative Pathology.