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Background The post-dialysis plasma level of human atrial natriuretic peptide (hANP) reflects the fluid volume in patients on hemodialysis. The threshold hANP level is reportedly 100 pg/mL; however, the clinical usefulness of the threshold hANP level for volume control has not been sufficiently studied. Methods We conducted a single-center, retrospective, observational study that included 156 hemodialysis patients without atrial fibrillation. First, we examined the usefulness of the threshold hANP level (100 pg/mL) for predicting hypoxemia due to congestion in a short-term observational study from December 30, 2015 to January 5, 2016. Subsequently, we conducted a 5-year follow-up study wherein the outcomes were hospitalization due to acute heart failure (AHF), development of cardiovascular diseases (CVD), and all-cause death. Finally, we collected echocardiography data to investigate the relationship between cardiac function and hANP. Results Our short-term observational study showed that patients with an hANP level ≥ 100 pg/mL developed hypoxemia due to congestion (odds ratio, 3.52; 95% confidence interval, 1.06–11.71; P = 0.040). At the 5-year follow-up, patients with an hANP level ≥ 100 pg/mL had significantly higher rates of hospitalization due to AHF, CVD, and all-cause death based on the log-rank test (P = 0.003, P = 0.019, P Conclusions The hANP level is indicative of both fluid volume and cardiac dysfunction. A threshold hANP level of 100 pg/mL can serve as a predictive marker for AHF and a practical indicator for volume control.

Objectives Anti-ribosomal P protein autoantibodies (anti-P) specifically develop in patients with systemic lupus erythematosus. Associations of anti-P with lupus nephritis (LN) histological subclass and renal outcome remain inconclusive. We sought to determine the association of anti-P and anti-double-stranded DNA antibody (anti-dsDNA) with renal histology and prognosis in LN patients. Methods Thirty-four patients with LN, having undergone kidney biopsy, were included. The 2018 revised ISN/RPS classification system was used for pathophysiological evaluation. Chronic kidney disease (CKD) was defined as an estimated glomerular filtration rate 2 for > 3 months. Results Six patients (17.6%) were positive for anti-P and 26 (76.5%) for anti-dsDNA. Among the six patients with anti-P, one did not have anti-dsDNA, but did have anti-Sm antibody, and showed a histological subtype of class V. This patient maintained good renal function for over 14 years. The remaining five patients, who had both anti-P and anti-dsDNA, exhibited proliferative nephritis and were associated with prolonged hypocomplementemia, and the incidence of CKD did not differ from patients without anti-P. Conclusion Although this study included a small number of patients, the results indicated that histology class and renal prognosis associated with anti-P depend on the coexistence of anti-dsDNA. Further studies with a large number of patients are required to confirm this conclusion.

Aim We evaluated several sarcopenia-related hormones, cytokines and uremic toxins to identify the humoral factors associated with sarcopenia and frailty in Japanese hemodialysis patients. Methods Twenty Japanese patients aged ≥65 years who underwent maintenance hemodialysis therapy at Uonuma Kikan Hospital for more than 6 months were included in this retrospective cross-sectional study. Clinical data, including physical function and mental state, were obtained from the clinical records collected during the regular evaluation at the beginning of each hemodialysis therapy session, 3 days after the previous hemodialysis therapy. The diagnosis of sarcopenia and frailty was based on the Asian Working Group for Sarcopenia 2019 and the Japanese version of the Cardiovascular Health Study, respectively. The mental state of patients was evaluated using the Japanese version of the Patient Health Questionnaire 9 (J-PHQ-9). Results In univariate analyses, plasma brain-derived neurotrophic factor (BDNF) levels were significantly lower in patients with severe sarcopenia and frailty. The plasma BDNF concentration was correlated with muscle strength and physical performances, such as the 6-m walk test, Short Physical Performance Battery and 5-time chair stand test. BDNF was also correlated with body weight, hemodialysis vintage, and serum levels of total protein and indoxyl sulfate but not with body mass index, appendicular skeletal muscle mass, serum interleukin 6 levels, or J-PHQ-9 scores. The odds ratio per 100 pg/mL of BDNF for the prevalence of frailty was 0.353. Conclusions BDNF is associated with decreased physical performance and the prevalence of severe sarcopenia and frailty in Japanese maintenance hemodialysis patients. Geriatr Gerontol Int 2021; 21: 27-33.

Inorganic polyphosphate (polyP) is a linear polymer of orthophosphate units that are linked by phosphoanhydride bonds and is involved in various pathophysiological processes. However, the role of polyP in immune cell dysfunction is not well-understood. In this study, using several biochemical and cell biology approaches, including cytokine assays, immunofluorescence microscopy, receptor-binding assays with quartz crystal microbalance, and dynamic light scanning, we investigated the effect of polyP on in vitro lipopolysaccharide (LPS)-induced macrophage inflammatory response. PolyP up-regulated LPS-induced production of the inflammatory cytokines, such as tumor necrosis factor α, interleukin-1β, and interleukin-6, in macrophages, and the effect was polyP dose– and chain length–dependent. However, orthophosphate did not exhibit this effect. PolyP enhanced the LPS-induced intracellular macrophage inflammatory signals. Affinity analysis revealed that polyP interacts with LPS, inducing formation of small micelles, and the polyP-LPS complex enhanced the binding affinity of LPS to Toll-like receptor 4 (TLR4) on macrophages. These results suggest that inorganic polyP plays a critical role in promoting inflammatory response by enhancing the interaction between LPS and TLR4 in macrophages.

Heavy chain deposition disease (HCDD) is a rare complication of plasma cell dyscrasias, characterized by nonamyloid tissue deposits of incomplete monoclonal heavy chains in renal tissues. We report the case of a 78-year-old female with HCDD who was successfully treated with bortezomib and dexamethasone (BD); histopathological improvements were confirmed by kidney biopsy after 2 years of chemotherapy. She presented with renal insufficiency, proteinuria, hematuria, hypogammaglobulinemia, and hypocomplementemia. Renal biopsy showed diffuse global nodular glomerulopathy with the deposition of IgG1 and C3 in the glomeruli and on the tubular basement membrane. Kappa and lambda light chains were not detected. Staining for the constant regions of the gamma heavy chain revealed the absence of the CH1 domain. These findings are consistent with those of gamma 1 HCDD. Results of liquid chromatography-tandem mass spectrometric analysis were consistent with the immunohistochemical results. Two years after weekly BD therapy, normalization of the kappa/lambda ratio and reduction of urinary protein excretion were achieved. A follow-up biopsy showed remarkable diminution of nodular lesions of glomeruli and deposits of IgG and C3. Keywords: Heavy chain deposition disease, Bortezomib, Liquid chromatography-tandem mass spectrometry

A 60-year-old male presented with accelerated hypertension, renal insufficiency, proteinuria, and hematuria. Percutaneous kidney biopsy revealed membranoproliferative glomerulonephritis (MPGN) without any immunoglobulin and complement deposition. On performing electron microscopy, deposits with a tubular, organized structure and approximately 60 nm in diameter were detected in the glomerular subendothelial spaces and mesangial areas. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) demonstrated the significantly increased deposition of fibrinogen and fibronectin in glomeruli. Immunohistochemistry and immunoelectron microscopy demonstrated that the deposits were composed of fibrinogen. Here we report a case of cryofibrinogen -associated GN in which LC-MS/MS and immunoelectron microscopy were useful for diagnosis. When MPGN with organized deposits without the deposition of immunoglobulins and complements is diagnosed, we considered the cryofibrinogen-associated GN in one of the differential diagnosis, and even skin symptoms cannot be detected. Keywords: Cryofibrinogen-related kidney disease, Liquid chromatography-tandem mass spectrometry, Immunoelectron microscopy

An accumulation of protein-bound uremic toxins (PBUTs) is one of major reasons for development of uremia-related complications. We examined the PBUT removal ability of a hexadecyl-immobilized cellulose bead (HICB)-containing column for patients undergoing hemodialysis. Adsorption of indoxyl sulfate (IS), a representative PBUT, to HICBs was examined in vitro. The HICB column was used in patients undergoing hemodialysis for direct hemoperfusion with a regular hemodialyzer. The serum IS, indole acetic acid (IAA), phenyl sulfate (PhS), and p-cresyl sulfate (PCS) levels were measured before and after passing the column. HICBs adsorbed protein-free (free) IS in a dose- and time-dependent manner in vitro (55.4 ± 1.4% adsorption of 1 millimolar, 251 µg/mL, IS for 1 h). In clinical studies, passing the HICB-containing column decreased the serum level of free IS, IAA, PhS, and PCS levels significantly (by 34.4 ± 30.0%, 34.8 ± 25.4%, 28.4 ± 18.0%, and 34.9 ± 22.1%, respectively), but not protein-bound toxins in maintenance hemodialysis patients. HICBs absorbed some amount of free PBUTs, but the clinical trial to use HICB column did not show effect to reduce serum PBUTs level in hemodialysis patients. Adsorption treatment by means of direct hemoperfusion with regular hemodialysis may become an attractive blood purification treatment to increase PBUT removal when more effective materials to adsorb PBUTs selectively will be developed.

Immunoglobulin A nephropathy (IgAN) is the most common glomerulonephritis worldwide, characterized by mesangial polymeric IgA1 deposition. IgAN is believed to develop owing to aberrant mucosal immunoreaction against commensals in the tonsils. However, the exact interrelation between pathogenic IgA and mucosal microbiota in IgAN patients is unclear.Biopsy-proven IgAN or recurrent tonsillitis (RT) patients who had undergone tonsillectomy were enrolled. We used 16S ribosomal RNA gene amplicon sequencing with a flow cytometry-based bacterial cell sorting technique) and immunoglobulin repertoire sequencing of the IgA heavy chain to characterize IgA-coated bacteria of the tonsillar microbiota (IgA-SEQ) and their corresponding IgA repertoire. Furthermore, we fractionated patient serum using gel-filtration chromatography and performed flow cytometry-based analysis of IgA binding to bacteria cultured from incised tonsils.Tonsillar proliferation-inducing ligand and B-cell activating factor levels were significantly higher in IgAN than in RT patients. IgA-SEQ for tonsillar microbiota revealed the preferential binding ability of IgA to Bacteroidetes in IgAN tonsils compared with those from RT patients. Expression of immunoglobulin heavy (IGH) constant alpha 1 with IGH variable 3-30 was significantly higher in IgAN than that in RT, and positively correlated with the IgA-coated enrichment score of Bacteroidetes. Serum polymeric IgA, comprising high levels of GdIgA1, exhibited considerable binding to Bacteroidetes strains cultured from the tonsils of IgAN patients.These findings provide evidence that aberrant mucosal immune responses to tonsillar anaerobic microbiota, primarily consisting of members of the phylum Bacteroidetes, are involved in IgAN pathophysiology.

IgA nephropathy (IgAN) is a chronic glomerular disease that causes end-stage renal disease in 20–40 % of patients within 20 years. The efficacy of tonsillectomy combined with steroid pulse (SP) administration (TSP) for clinical remission of IgAN has been reported. Particularly in Japan, TSP has been performed widely. However, the optimum method for steroid administration in TSP has not been established. We retrospectively compared clinical remission in IgAN patients treated with tonsillectomy combined with two different steroid administration methods: (1) three courses of SP therapy and oral prednisolone administered on alternate days (group 3A; n = 25); and (2) one course of SP therapy and oral prednisolone administered on consecutive days (group 1C; n = 22). There was no significant difference in the clinical remission rates between the two groups at 12 (48.0 vs. 40.9 %, P = 0.77) and 24 months after starting treatment (68.0 vs. 72.7 %, P = 0.76) and at the final observation (76.0 vs. 81.8 %, P = 0.73). The mean period from starting treatment to remission of hematuria in group 3A was significantly shorter than that in group 1C (5.7 ± 4.4 vs. 9.9 ± 5.9 months, P = 0.03). Dyslipidemic patients treated for the first time with statin after the SP therapy were more present in group 3A at 24 months (P = 0.02). In IgAN patients, treatment of group 3A may be effective for inducing rapid remission of hematuria. Further studies are needed to establish an appropriate protocol for TSP.

A 36-year-old woman who was undergoing dialysis for end-stage kidney disease (ESKD) was admitted to our hospital with consciousness disorder. She was diagnosed with Budd-Chiari syndrome due to antiphospholipid syndrome at the age of 28 years. Her kidney function and leg edema gradually deteriorated. After initiation of hemodialysis (HD), transient loss of consciousness due to hepatic encephalopathy during HD treatment occurred frequently. Her kidney replacement therapy was changed to online hemodiafiltration (HDF), which dramatically improved her hepatic coma. Compared with HD, HDF contributed to the increase in Fischer's ratio and decrease in tryptophan level, which has a high protein-bound property. This case suggests that HDF may be beneficial for hepatic encephalopathy in ESKD patients by modulating the amino acid profile.

Leptin, one of the typical adipokines, is reported to promote T h 17 cell responses and to enhance production of proinflammatory cytokines. To clarify the role of leptin in the regulation of the IL-23/IL-17 axis and the development of kidney disease, we used a murine model of nephrotoxic serum (NTS) nephritis (NTN). Sheep NTS was administered in wild-type C57BL/6J mice and food-restricted, leptin-deficient C57BL/6J- ob/ob (FR- ob/ob ) mice after preimmunization with sheep IgG. The profile of mRNA expression relevant to T helper lymphocytes in the kidneys was analyzed by quantitative real-time PCR (qRT–PCR). Cultured murine glomerular podocytes and peritoneal exudate macrophages (PEMs) were used to investigate the direct effect of leptin on IL-23 or MCP-1 production by qRT–PCR. Kidney injury and macrophage infiltration were significantly attenuated in FR- ob/ob mice 7 days after NTS injection. The T h 17-dependent secondary immune response against deposited NTS in the glomeruli was totally impaired in FR- ob/ob mice because of deteriorated IL-17 and proinflammatory cytokine production including IL-23 and MCP-1 in the kidney. IL-23 was produced in glomerular podocytes in NTN mice and cultured murine glomerular podocytes produced IL-23 under leptin stimulation. MCP-1 production in PEMs was also promoted by leptin. Induction of MCP-1 expression was observed in PEMs regardless of Ob-Rb, and the leptin signal was transduced without STAT3 phosphorylation in PEMs. Leptin deficiency impairs the secondary immune response against NTS and down-regulates IL-23 production and T h 17 responses in the NTN kidney, which is accompanied by decreased MCP-1 production and macrophage infiltration in the NTN kidney.

The Oxford classification of IgA nephropathy consists of four markers as prognosticators. We retrospectively examined the relevance of extracapillary proliferation involving cellular and fibrocellular crescents (Ex) and arteriolar hyalinosis (A) on the long-term outcome of renal function. A total of 314 Japanese patients who were diagnosed with IgA nephropathy, with 12 months or more of follow-up period were included in this study. A total of 186 patients were with UP ≥ 0.5 g/day. Patients with diabetes mellitus or severe kidney injury (eGFR

Senescent cells have deleterious effects on the tissue microenvironment through proinflammatory senescence-associated secretory phenotypes; meanwhile, the onset of glomerulonephritis is predominant in younger adults. To clarify the influence of aging on the onset and development of glomerulonephritis, we used a murine model of antibody-mediated nephritis. Sheep nephrotoxic serum was administered in C57BL/6J mice at 12 weeks (adult) or 18 months old (aged) after pre-immunization with sheep IgG. Depositions of sheep IgG and autologous mouse IgG along the glomerular basement membrane and the serum titer of anti-sheep IgG-specific mouse IgG were similar between adult and aged mice. However, kidney injury was depressed in aged mice, accompanied by reduced macrophage infiltration in the glomeruli. The mRNA expression of most chemokines involved in monocyte/macrophage chemotaxis was not different between adult and aged mice, but the cell surface expression of C-C chemokine receptor (CCR) 1 and CCR2 was down-regulated in the monocyte/macrophage lineage cells infiltrating the kidneys of aged nephritic mice. Furthermore, expression of all four isotypes of the Fcγ receptor (FcγR) was reduced in these cells. Both CCR and FcγR expression were down-regulated in monocyte/macrophage lineage cells, resulting in attenuated glomerular infiltration of these cells and impaired glomerular injury in aged mice.

Background It is well known that atrophic renal changes are associated with chronic kidney disease (CKD) progression, but conventional diagnostic imaging methods such as noncontrast-enhanced computed tomography and magnetic resonance imaging (MRI) have been insufficient for precisely assessing kidney function because they cannot clearly distinguish between the medulla and cortex. Hence, here we used noncontrast-enhanced steady-state free precession (SSFP) MRI with a spatially selective inversion recovery (IR) pulse to improve visibility for renal corticomedullary differentiation and evaluated the association between morphological parameters and kidney function in patients with CKD. Methods Kidney corticomedullary contrast ratio, cortical and medullary areas, and minimal cortical thickness of 107 patients with CKD G1–G5 were measured using SSFP MRI with a spatially selective IR pulse and the association between these morphological parameters and kidney function were evaluated. Results Corticomedullary contrast ratio was significantly improved on SSFP MRI compared with conventional in-phase T1-weighted gradient-echo MRI and positively correlated with estimated glomerular filtration ratio (eGFR), raw eGFR, and 24-h creatinine clearance. The medullary and cortical areas and minimal cortical thickness also positively correlated with those of kidney functional markers and the age. In patients with CKD and diabetes mellitus (DM), the correlation coefficients between raw eGFR and morphological parameters were higher than those in patients without DM, while minimal cortical thickness was larger in CKD patients with DM with a raw eGFR ≥ 45 mL/min. Conclusion Kidney morphological parameters measured with SSFP MRI were clearly correlated with kidney function in patients with CKD, including those with advanced kidney dysfunction.

In order to clarify the interaction between cardiac dysfunction and sodium homeostasis in the kidney, we used a murine model of cardiac dysfunction and investigated the effect on sodium transporters in renal tubular cells.Cardiac function was deteriorated by abdominal aortic banding, and the gene expression of sodium transporters in the kidneys was evaluated by real-time RT-PCR and compared with that in the kidneys of control mice.Gene expression of all three variants of the murine prolactin receptor was enhanced by aortic banding. Upregulated prolactin receptor was distributed in the proximal tubular cells of the pars recta in the deep inner cortex and the outer stripe of the outer medulla. Prolactin has been reported to be a natriuretic hormone that inhibits proximal tubular Na(+)/K(+)-ATPase activity, resulting in reduced sodium reabsorption and the acceleration of natriuresis. Inhibition of endogenous prolactin secretion by bromocriptine administration decreased the urine sodium excretion in both aortic banding and control mice. On the other hand, excess exogenous prolactin administration enhanced urine potassium excretion in aortic banding mice. Furthermore, a high-sodium diet accelerated urinary sodium excretion, which was also significantly decreased by inhibition of endogenous prolactin secretion in aortic banding mice.We reported that the prolactin receptor was upregulated by aortic banding treatment. Prolactin-prolactin receptor interaction in the proximal tubular cells of the pars recta should involve a different mechanism of kaliuresis other than inhibition of Na(+)/K(+)-ATPase.

An accumulation of protein-bound uremic toxins (PBUTs) is one of major reasons for development of uremia-related complications. We examined the PBUT removal ability of a hexadecyl-immobilized cellulose bead (HICB)-containing column for patients undergoing hemodialysis. Adsorption of indoxyl sulfate (IS), a representative PBUT, to HICBs was examined in vitro. The HICB column was used in patients undergoing hemodialysis for direct hemoperfusion with a regular hemodialyzer. The serum IS, indole acetic acid (IAA), phenyl sulfate (PhS), and p-cresyl sulfate (PCS) levels were measured before and after passing the column. HICBs adsorbed protein-free (free) IS in a dose- and time-dependent manner in vitro (55.4 ± 1.4% adsorption of 1 millimolar, 251 µg/mL, IS for 1 h). In clinical studies, passing the HICB-containing column decreased the serum level of free IS, IAA, PhS, and PCS levels significantly (by 34.4 ± 30.0%, 34.8 ± 25.4%, 28.4 ± 18.0%, and 34.9 ± 22.1%, respectively), but not protein-bound toxins in maintenance hemodialysis patients. HICBs absorbed some amount of free PBUTs, but the clinical trial to use HICB column did not show effect to reduce serum PBUTs level in hemodialysis patients. Adsorption treatment by means of direct hemoperfusion with regular hemodialysis may become an attractive blood purification treatment to increase PBUT removal when more effective materials to adsorb PBUTs selectively will be developed.

There have been several lines of evidences for familial aggregation of IgA nephropathy (IgAN), as well as mesangial deposition of IgA, suggesting that the susceptibility to this disease is genetically controlled. In our institute, family histories of hematuria, end-stage kidney disease, and glomerulonephritis are observed in about 10 % of cases with IgAN, even in those without any significant hereditary nephritis or kidney diseases. Recent large-scale genome-wide association studies (GWAS) of sporadic IgAN have identified multiple susceptibility loci, providing an insight into the genetic architecture of this disease, although each of their individual impact to the development of the disease is still not enough. It has been recognized that most of these loci are either directly associated with risk of inflammatory bowel disease (IBD) or maintenance of the intestinal epithelial barrier and response to mucosal pathogens. Further elucidation of the role of genetic variants underlying IgAN, and hologenetic views of gene variants and environmental factors, would be necessary to understand the precise pathogenic mechanism of IgAN in more detail.

A 31-year-old woman with proteinuria, hypocomplementemia, rheumatoid factor, and high serum polyclonal IgM concentration was admitted to our hospital for renal biopsy. She had a past history of two renal biopsies. When she was 12 years old, she developed proteinuria, microscopic hematuria, and hypocomplementemia. She was diagnosed as having ‘IgM nephropathy’ based on minor glomerular abnormalities as determined by light microscopy and IgM and C3 deposition in the mesangial region by immunofluorescence microscopy at the first biopsy. Despite corticosteroid treatment, her proteinuria did not improve and she discontinued regular outpatient checkups. When she was 29 years old and pregnant, she developed preeclampsia and, after delivery, a second renal biopsy was implemented. She was diagnosed as having progressed ‘IgM nephropathy’ with endotheliosis induced by preeclampsia. She was treated with angiotensin II receptor blocker and her proteinuria diminished; however, 1 year after the delivery, she developed proteinuria again, along with microscopic hematuria and hypocomplementemia. A third renal biopsy was conducted at 31 years of age and she was diagnosed as having membranoproliferative glomerulonephritis (MPGN) type I on the basis of diffuse mesangial proliferation, endocapillary hypercellularity with double contour of the capillary wall, and lobular formation in glomeruli, as determined by light microscopy. Immunofluorescence staining demonstrated deposits of C3, C4, C1q, and IgM in the mesangial region and capillary wall. She underwent corticosteroid therapy followed by normalization of urinalysis and serum complement level. Although she had initially been diagnosed with ‘IgM nephropathy’, she was finally diagnosed with secondary MPGN and was successfully treated by corticosteroid therapy.

Gastric antral vascular ectasia (GAVE) is currently recognized as an important cause of gastrointestinal bleeding. Chronic kidney disease (CKD) is associated with a high incidence of GAVE. We report 3 patients with CKD who presented with severe anemia and were diagnosed with GAVE; they were resistant to endoscopic argon plasma coagulation. However, remission of anemia and improvement in GAVE lesions were observed after the initiation of hemodialysis. The pathogenesis of GAVE remains largely unknown, but mechanical stress of the antrum could play an important role. This stress may be reduced by hemodialysis through improvement of uremia-associated gastrointestinal symptoms. Therefore, the initiation of hemodialysis might be effective for intractable GAVE in CKD patients.

In chronic kidney disease (CKD) patients, accumulation of uremic toxins is associated with cardiovascular risk and mortality. One of the hallmarks of kidney disease-related cardiovascular disease is intravascular macrophage inflammation, but the mechanism of the reaction with these toxins is not completely understood. Macrophages differentiated from THP-1 cells were exposed to indoxyl sulfate (IS), a representative uremic toxin, and changes in inflammatory cytokine production and intracellular signaling molecules including interleukin (IL)-1, aryl hydrocarbon receptor (AhR), nuclear factor (NF)-κ, and mitogen-activated protein kinase (MAPK) cascades as well as the NLRP3 inflammasome were quantified by real-time PCR, Western blot analysis, and enzyme-linked immunosorbent assay. IS induced macrophage pro-IL-1β mRNA expression, although mature IL-1 was only slightly increased. IS increased AhR and the AhR-related mRNA expression; this change was suppressed by administration of proteasome inhibitor. IS promoted phosphorylation of NF-κB p65 and MAPK enzymes; the reaction and IL-1 expression were inhibited by BAY11-7082, an inhibitor of NF-κB. In contrast, IS decreased NLRP3 and did not change ASC, pro-caspase 1, or caspase-1 activation. IS-inducing inflammation in macrophages results from accelerating AhR-NF-κB/MAPK cascades, but the NLRP3 inflammasome was not activated. These reactions may restrict mature IL-1β production, which may explain sustained chronic inflammation in CKD patients.

We present here a male patient who had developed nephrotic syndrome 11 yr after kidney transplantation. Nephrotic syndrome suddenly occurred after severe sunburn he got in Hawaii. Such a clinical course seemed very rare in kidney transplantation, and multifactorial etiology was suspected. The histological findings of graft biopsy were intricate. On light microscopy, there were mesangial expansion and endocapillary proliferation with duplication of GBM and crescent formation. Deposits of IgM in mesangium were the most prominent finding on immunofluorescence microscopy, but IgA and C3 deposits were also detected. Electron microscopy revealed paramesangial and a few subepithelial dense deposits. Additionally, small organized deposits were found in the subepithelial space. Based on these findings, a provisional diagnosis of IgA nephropathy superimposed on chronic transplant glomerulopathy was made. However, hepatitis C virus related nephropathy could not be excluded.

One of the possible causes of enhanced atherosclerosis in patients with chronic kidney disease (CKD) is the accumulation of uremic toxins. Since macrophage foam cell formation is a hallmark of atherosclerosis, we examined the direct effect of indoxyl sulfate (IS), a representative uremic toxin, on macrophage function. Macrophages differentiated from THP-1 cells were exposed to IS in vitro. IS decreased the cell viability of THP-1 derived macrophages but promoted the production of inflammatory cytokines (IL-1β, IS 1.0 mM: 101.8 ± 21.8 pg/mL vs. 0 mM: 7.0 ± 0.3 pg/mL, TNF-α, IS 1.0 mM: 96.6 ± 11.0 pg/mL vs. 0 mM: 15.1 ± 3.1 pg/mL) and reactive oxygen species. IS reduced macrophage cholesterol efflux (IS 0.5 mM: 30.3% ± 7.3% vs. 0 mM: 43.5% ± 1.6%) and decreased ATP-binding cassette transporter G1 expression. However, lipid uptake into cells was not enhanced. A liver X receptor (LXR) agonist, T0901317, improved IS-induced production of inflammatory cytokines as well as reduced cholesterol efflux. In conclusion, IS induced inflammatory reactions and reduced cholesterol efflux in macrophages. Both effects of IS were improved with activation of LXR. Direct interactions of uremic toxins with macrophages may be a major cause of atherosclerosis acceleration in patients with CKD.

Immunoglobulin G (IgG) mediates pro- and anti-inflammatory activities through the engagement of its Fc fragment (Fc) with distinct Fcg receptors (FcgRs). One class of Fc-FcgR interactions generates pro-inflammatory effects of immune complexes and cytotoxic antibodies. In contrast, therapeutic intravenous gamma globulin and its Fc fragments are anti-inflammatory. We show here that these distinct properties of the IgG Fc result from differential sialylation of the Fc core polysaccharide. IgG acquires anti-inflammatory properties upon Fc sialylation, which is reduced upon the induction of an antigen-specific immune response. This differential sialylation may provide a switch from innate anti-inflammatory activity in the steady state to generating adaptive pro-inflammatory effects upon antigenic challenge.

Introduction of heterologous anti-glomerular basement membrane antiserum (nephrotoxic serum, NTS) into presensitized mice triggers the production of IgG anti-NTS antibodies that are predominantly IgG2b and the glomerular deposition of pathogenic immune complexes, leading to accelerated renal disease. The pathology observed in this model is determined by the effector cell activation threshold that is established by the coexpression on infiltrating macrophages of the IgG2a/2b restricted activation receptor FcgammaRIV and its inhibitory receptor counterpart, FcgammaRIIB. Blocking FcgammaRIV with a specific monoclonal antibody thereby preventing IgG2b engagement or treatment with high dose intravenous gamma-globulin (IVIG) to down-regulate FcgammaRIV while up-regulating FcgammaRIIB, protects mice from fatal disease. In the absence of FcgammaRIIB, IVIG is not protective; this indicates that reduced FcgammaRIV expression alone is insufficient to protect animals from pathogenic IgG2b immune complexes. These results establish the significance of specific IgG subclasses and their cognate FcgammaRs in renal disease.

Bezafibrate suppresses rat antiglomerular basement membrane crescentic glomerulonephritis. Background The immunoregulatory activity of ligands for peroxisome proliferator-activated receptors (PPARs) has been recently paid attention. The regulatory effect of bezafibrate (BZF), a ligand for PPARα on glomerulonephritis was investigated using a rat anti-glomerular basement membrane (GBM) glomerulonephritis model. Methods The effect on development of anti-GBM glomerulonephritis was examined by treatment with BZF from day -7 to day 7 after intravenous injection of rabbit anti-GBM serum into Wistar Kyoto (WKY) rats. The therapeutic efficacy after onset of the glomerulonephritis was also checked by treatment with BZF from day 3 to 7. On day 7, the condition was evaluated histologically. The expression of a tissue injury molecule, macrophage metalloesterase (MME), was measured by Northern blot analysis. The suppressive effect on immune cells was assessed by proliferation assay with mitogen-stimulated rat spleen cells. Results Histopathologic changes induced by anti-GBM in rats treated with BZF (day -7 to day 7) were markedly suppressed in a dose-dependent fashion. Infiltration of ED-1+ macrophages in glomeruli, proteinuria, and mRNA expression of MME in kidneys were diminished in parallel with histologic improvement. Moreover, the disease activity was also attenuated even by the treatment after onset of the glomerulonephritis (day 3 to 7). The mitogen-induced proliferation of spleen cells was down-regulated at concentrations of BZF, which were equivalent to those in sera of BZF-treated rats. Conclusion BZF markedly suppresses the activity of rat anti-GBM crescentic glomerulonephritis. Fibrates might serve as a therapeutic option for crescentic glomerulonephritis.

Transforming growth factor (TGF)-beta1, a multifunctional cytokine, which regulates proliferation and differentiation of a variety of cell types, has the central role in the development and progression of renal injury in both animal models and human. Although it has been suggested that genetic variations in the TGF-beta1 gene are associated with the activity of the gene product, their clinical significance in glomerular disease is unknown. We investigated whether the polymorphisms of C-509T and T869C in TGF-beta1 account for interindividual variation in manifestations of IgA nephropathy (IgAN) using 626 Japanese subjects including 329 patients with histologically proven IgAN and 297 healthy controls with normal urinalysis. The frequencies of genotypes, alleles, and major haplotypes were similar between the patients and controls. The C-509T and T869C polymorphisms were in tight linkage disequilibrium, and the major haplotypes were C-C and T-T, which accounted for more than 95% of the total. In patients with -509CC and in those with the 869CC, urinary protein excretion was higher than in those with other genotypes, whereas no difference in other clinical manifestations was noted. Moreover, patients with -509CC and those with 869CC genotypes presented with a significant higher score of mesangial cell proliferation than in those with other genotypes. These results suggest that TGF-beta1 gene polymorphisms are specifically associated with heavy proteinuria and mesangial cell proliferation in Japanese patients with IgAN, although they do not confer susceptibility to this disease.

Sarcoidosis is a systemic disorder associated with granuloma characterized by an abnormal T(h)1-type cytokine production and accumulation of T(h)1 CD4 T cells in the granuloma lesions, suggesting an importance of T(h)1 responses in sarcoidosis. However, the pathogenesis of sarcoidosis remains to be solved. Here, we investigated the nature of V(alpha)24 NKT cells with immunoregulatory functions in sarcoidosis. Patients with non-remitting sarcoidosis displayed a decrease in the number of V(alpha)24 NKT cells in peripheral blood, but an accumulation of these cells in granulomatous lesions. When stimulated with the specific glycolipid ligand, alpha-galactosylceramide, peripheral blood V(alpha)24 NKT cells from patients with non-remitting disease produced significantly less IFN-gamma than those from healthy volunteers, but normal levels of IL-4. The reduced IFN-gamma production was observed only in V(alpha)24 NKT cells and not conventional CD4 T cells, but was normal in patients with remitting disease, suggesting that non-remitting sarcoidosis involves an insufficient IFN-gamma production of V(alpha)24 NKT cells which is well correlated with disease activity. Thus, these results suggest that V(alpha)24 NKT cells play a crucial role in the disease status of sarcoidosis.

Background: Thrombotic occlusion is a frequent complication of central venous catheters used to provide temporary blood access on hemodialysis therapy. Heparin-lock is conventionally used to maintain patency of the catheter, but the necessity of heparin-lock has not been determined yet. Methods: After the immobilized-urokinase double-lumen central venous catheter was inserted into 48 Japanese hemodialysis patients, 22 patients randomized to the heparin group received a 20-ml saline-flush, followed by 2 ml of 1,000 U/ml heparin-lock, and 26 patients randomized to the saline group received only the 20-ml saline-flush once a day for each lumen. Results: Thrombotic occlusion was observed in only 1 out of 22 patients in the heparin group and 1 out of 26 patients in the saline group. No significant difference of the catheter survival was observed between the two groups (p = 0.8599). Conclusions: Natural saline-flush is sufficient for maintaining the patency of an immobilized-urokinase double-lumen central venous catheter.

Rat anti-glomerular basement membrane (GBM) nephritis is a model of crescentic glomerulonephritis induced by injection of anti-GBM antiserum. To elucidate the mechanism of glomerular injury, we analyzed the gene expression patterns in the kidneys of anti-GBM nephritis rats using DNA arrays, and found that macrophage metalloelastase/matrix metalloproteinase (MMP)-12 was one of the highly expressed genes in the kidneys on days 3 and 7 after the injection of anti-GBM antiserum. Enhancement of MMP-12 mRNA expression was confirmed by Northern blot analysis, and in situ hybridization revealed that MMP-12 mRNA was expressed in ED-1-positive macrophages and multinuclear giant cells in the glomeruli with crescent. Moreover, these cells were positive with anti-rat rMMP-12 Ab on the section of the kidneys of anti-GBM nephritis rats on day 7. To clarify the role of MMP-12, we conducted a neutralization experiment using anti-rat rMMP-12 Ab, which had an ability to inhibit rMMP-12 activity of degrading natural substrate such as bovine elastin or human fibronectin in vitro. Anti-rat rMMP-12 Ab or control Ig was injected in each of six rats on days 0, 2, 4, and 6 after the injection of anti-GBM antiserum. Consequently, crescent formation and macrophage infiltration in the glomeruli were significantly reduced in the rats treated with anti-rat rMMP-12 Ab, and the amount of urine protein was also decreased. These results disclosed that MMP-12 played an important role in glomerular injury in a crescentic glomerulonephritis model, and inhibition of MMP-12 may lead to a new therapeutic strategy for this disease.

The administration of concanavalin A (Con A) induces a rapid severe injury of hepatocytes in mice. Although the Con A-induced hepatitis is considered to be an experimental model of human autoimmune hepatitis, the precise cellular and molecular mechanisms that induce hepatocyte injury remain unclear. Here, we demonstrate that Valpha14 NKT cells are required and sufficient for induction of this hepatitis. Moreover, interleukin (IL)-4 produced by Con A-activated Valpha14 NKT cells is found to play a crucial role in disease development by augmenting the cytotoxic activity of Valpha14 NKT cells in an autocrine fashion. Indeed, short-term treatment with IL-4 induces an increase in the expression of granzyme B and Fas ligand (L) in Valpha14 NKT cells. Moreover, Valpha14 NKT cells from either perforin knock-out mice or FasL-mutant gld/gld mice fail to induce hepatitis, and hence perforin-granzyme B and FasL appear to be effector molecules in Con A-induced Valpha14 NKT cell-mediated hepatocyte injury.

Murine NKT cells can recognize alpha-galactosylceramide (alpha-GalCer) in the context of a class Ib CD1d molecule. Here we show that alpha-GalCer can selectively activate freshly isolated human Valpha24(+)Vbeta11(+) cells, functionally defining the human NKT cells. The naive human NKT cell repertoire consisted of cells expressing an invariant Valpha24JalphaQ chain and a diverse array of beta chains derived from a single Vbeta11 gene segment. Stimulation with alpha-GalCer expanded a polyclonal subset of the human NKT cell repertoire carrying a novel complementarity-determining region (CDR) 3beta consensus motif that may directly interact with the sugar moiety of alpha-GalCer. Our data suggest that certain redundancy is allowed for CDR3beta of NKT antigen receptor to interact with the ligand and provide a first clue to understand the novel protein-carbohydrate interaction mechanisms.

IgA nephropathy (IgAN) is characterized by mesangial deposition of IgA1 and galactose-deficient IgA1 is expected to play a pathogenic role. However, the identity of the receptor for IgA1 is still controversial. Hence, the aim of this study was to explore the receptor for galactose-deficient IgA1. Human monoclonal IgA1 was treated with exoglycosidase and FITC-conjugated control, asialo- and agalactosyl-IgA1 was used as a probe to detect the receptor in cultured human mesangial cells. Tumor necrosis factor-α or transforming growth factor-β1 treatment accelerated IgA1-binding on mesangial cells, and these effects were diminished by the addition of dexamethasone, whereas these changes were not dependent on galactose-deficiency of IgA1. According to comprehensive gene expression analysis, we focused on integrin β1. Pre-treatment by Mn(2+), which activates integrin by changing its structure, enhanced the binding of IgA1 in cultured mesangial cells. Furthermore, pre-incubation with collagens specifically enhanced binding of IgA1 in the cultured human mesangial cells without activation by Mn(2+). Collagen type IV distributed in the mesangial region of the glomeruli as well as Bowman's capsule and tubular basal membrane in IgAN patients, and the IgA1 with collagen type IV induced proliferative signals on mesangial cells by phosphorylating extracellular signal-regulated kinase more effectively than the IgA1 alone. Immunoprecipitation assay revealed the binding of IgA1 and integrin α1/β1 and α2/β1 heterodimer and down-regulation of integrin α1, α2 and β1 expression in human mesangial cells induced by each specific small interfering RNA diminished the ability to bind IgA1 probe. Integrin α1/β1 and α2/β1 would be a candidate receptor for IgA1.

Incompleteness of O-glycosylation in the IgA1 hinge has been implicated as a central mechanism in the development of IgA nephropathy. Although underglycosylation was reported to be an acquired abnormality, genes for enzymes of O-glycosylation, such as C1GALT1, may be responsible for susceptibility to IgA nephropathy.

Monocyte chemoattractant protein (MCP)-1 is closely related to the pathogenesis of the progression of various chronic renal diseases, including IgA nephropathy (IgAN), through its chemoattractant effect on macrophages. However, the correlation of MCP-1 gene polymorphism with the long-term prognosis of Japanese patients with IgAN has not been clearly determined yet.We investigated 277 Japanese patients diagnosed with IgAN based on renal biopsy to clarify the association between the progression of IgAN and MCP-1 gene polymorphism at position A-2518G, which regulates the transcription of the MCP-1 gene.The incidence of endstage renal disease was significantly higher in patients with the AA genotype (47.1%) compared to those with the AG (24.1%) or GG (27.4%) genotype (P = 0.024). Moreover, Kaplan-Meier analysis revealed that the AA genotype significantly facilitated the progression of renal disease (log rank; P = 0.0029), and Cox proportional hazards regression model analysis showed that the AA genotype represented a 2.058-fold risk for the progression of renal disease (P = 0.026) compared to the AG/GG genotype. However, when the patients were treated with angiotensin-converting enzyme inhibitor and/or angiotensin receptor blocker, or corticosteroid, homozygosity for the -2518A allele was not associated with a higher rate of incidence of endstage renal disease. Serum MCP-1 levels were higher although not significantly so, in the patients with IgAN possessing the AA genotype.The AA genotype at MCP-1 -2518 was an independent risk factor for the progression of renal disease in Japanese patients with IgAN, and was closely associated with renal survival.

Sarcoidosis is a systemic disorder associated with granuloma characterized by an abnormal T(h)1-type cytokine production and accumulation of T(h)1 CD4 T cells in the granuloma lesions, suggesting an importance of T(h)1 responses in sarcoidosis. However, the pathogenesis of sarcoidosis remains to be solved. Here, we investigated the nature of V(alpha)24 NKT cells with immunoregulatory functions in sarcoidosis. Patients with non-remitting sarcoidosis displayed a decrease in the number of V(alpha)24 NKT cells in peripheral blood, but an accumulation of these cells in granulomatous lesions. When stimulated with the specific glycolipid ligand, alpha-galactosylceramide, peripheral blood V(alpha)24 NKT cells from patients with non-remitting disease produced significantly less IFN-gamma than those from healthy volunteers, but normal levels of IL-4. The reduced IFN-gamma production was observed only in V(alpha)24 NKT cells and not conventional CD4 T cells, but was normal in patients with remitting disease, suggesting that non-remitting sarcoidosis involves an insufficient IFN-gamma production of V(alpha)24 NKT cells which is well correlated with disease activity. Thus, these results suggest that V(alpha)24 NKT cells play a crucial role in the disease status of sarcoidosis.

Transferrin saturation versus reticulocyte hemoglobin content for iron deficiency in Japanese hemodialysis patients.BackgroundIron deficiency is a frequent cause of recombinant human erythropoietin (rhEPO)-resistant anemia in hemodialysis patients. Both reticulocyte hemoglobin content (CHr) and transferrin saturation (TSAT) have been proposed as markers of iron deficiency, but it is unclear which parameter is superior.MethodsTo compare the efficacy of CHr and TSAT as an indicator for treatment of iron deficiency, we conducted a single-center, open-label, prospective, randomized, controlled trial at the Kidney Center in Shinraku-en Hospital of 197 Japanese patients on chronic hemodialysis. After 4 weeks of run-in period during which iron supplementation was suspended, 100 patients who were randomized to the CHr group received 240 mg iron colloid intravenously over 2 weeks when CHr less than 32.5 pg, and 97 patients who were randomized to the TSAT group received the same doses of iron colloid when TSAT less than 20%. We measured the rhEPO dose needed to maintain prestudy hematocrit levels, hematocrit, CHr, TSAT, serum ferritin, percentage of hypochromic red blood cells, and total iron administered.ResultsSixteen weeks later, 94 patients in the CHr group and 89 patients in the TSAT group finished the study. The doses of rhEPO required decreased by 35.8% (4081 to 2629 U/week, P < 0.005) in the TSAT group, but not significantly in the CHr group (4121 to 3606 U/week). Although CHr increased promptly after the iron administration in both groups, TSAT increased only in the TSAT group.ConclusionsAlthough CHr reflects the iron status more sensitively, TSAT is a better clinical marker for iron supplementation therapy.

Valpha14 natural killer T (NKT) cells produce large amounts of both IL-4 and IFN-gamma upon stimulation with a ligand, alpha-galactosylceramide (alpha-GalCer), and play a crucial role in various immune responses, including allergic diseases. Interestingly, Valpha14 NKT cells are not essential for the induction of IgE responses but rather induce suppression of specific IgE production upon activation. The suppression in the IgE production is not detected either in Valpha14 NKT cell-deficient mice or in IFN-gamma-deficient mice. Thus, activated Valpha14 NKT cells are likely to exert a potent suppressive activity on Th2 cell differentiation and subsequent IgE production by producing a large amount of IFN-gamma. In marked contrast, little regulatory effect of IL-4 produced by Valpha14 NKT cells on Th2 cell differentiation is suggested.

The proximal promoter of lck directs gene expression exclusively in T cells. To investigate the developmental regulation of the lck proximal promoter activity and its relationship to T cell lineage commitment, a green fluorescence protein (GFP) transgenic (Tg) mouse in which the GFP expression is under the control of the proximal promoter of lck was created. In the adult GFP-Tg mice, >90% of CD4(+)CD8(+) and CD4(+)CD8(-) thymocytes, and the majority of CD4(-)CD8(+) and CD4(-)CD8(-) [double-negative (DN)] thymocytes were highly positive for GFP. Slightly lower but substantial levels of expression of GFP was also observed in mature splenic T cells. No GFP(+) cells was detected in non-T lineage subsets, including mature and immature B cells, CD5(+) B cells, and NK cells, indicating a preserved tissue specificity of the promoter. The earliest GFP(+) cells detected were found in the CD44(+)CD25(-) DN thymocyte subpopulation. The developmental potential of GFP(-) and GFP(+) cells in the CD44(+)CD25(-) DN fraction was examined using in vitro culture systems. The generation of substantial numbers of alphabeta and gammadelta T cells as well as NK cells was demonstrated from both GFP(-) and GFP(+) cells. However, no development of B cells or dendritic cells was detected from GFP(+) CD44(+)CD25(-) DN thymocytes. These results suggest that the progenitors expressing lck proximal promoter activity in the CD44(+)CD25(-) DN thymocyte subset have lost most of the progenitor potential for the B and dendritic cell lineage. Thus, progression of T cell lineage restriction in the earliest thymic population can be visualized by lck proximal promoter activity, suggesting a potential role of Lck in the T cell lineage commitment.