Long-term effectiveness of a primary care practice facilitation program for chronic kidney disease management: an extended follow-up of a cluster-randomized FROM-J study.

BACKGROUND: Practice facilitation program by multidisciplinary care for primary care physicians (PCPs) is expected to improve chronic kidney disease (CKD) outcomes, but there is no clear evidence of its long-term effectiveness. We have previously performed a cluster-randomized controlled trial for 3.5 years (the Frontier of Renal Outcome Modifications in Japan (FROM-J) study) with two arms-group A without the program and group B with the program. We aimed to assess the long-term effectiveness of the practice facilitation program on CKD outcomes via an extended 10-year follow-up of the FROM-J study. METHODS: We enrolled patients who were in the FROM-J study. The primary composite endpoint comprised cardiovascular disease (CVD), renal replacement therapy initiation and a 50% decrease in the estimated glomerular filtration rate (eGFR). The secondary endpoints were survival rate, eGFR decline rate and collaboration rate between PCPs and nephrologists. RESULTS: The occurrence of the primary composite endpoint tended to be lower in group B (group A: 27.1% versus group B: 22.1%, P = 0.051). Furthermore, CVD incidence was remarkably lower in group B (group A: 10.5% versus group B: 6.4%, P = 0.001). Although both mortality and the rate of eGFR decline were identical between both groups, the eGFR decline rate was significantly better in group B than in group A only in patients with stage G3a at enrollment (group A: 2.35 ± 3.87 mL/min/1.73 m2/year versus group B: 1.68 ± 2.98 mL/min/1.73 m2/year, P = 0.02). The collaboration rate was higher in group B. CONCLUSIONS: The CKD practice facilitation program for PCPs reliably decreases CVD events and may reduce the progression of cases to end-stage kidney disease.

Better remission rates in elderly Japanese patients with primary membranous nephropathy in nationwide real-world practice: The Japan Nephrotic Syndrome Cohort Study (JNSCS).

BACKGROUND: The aim of the present study was to clarify the prevalence of immunosuppressive drug use and outcomes in elderly and non-elderly patients with primary membranous nephropathy (MN) in nationwide real-world practice in Japan. PATIENTS AND METHODS: Between 2009 and 2010, 374 patients with primary nephrotic syndrome were enrolled in the cohort study (The Japan Nephrotic Syndrome Cohort Study, JNSCS), including 126 adult patients with MN. Their clinical characteristics were compared with those of nephrotic patients with primary MN registered in a large nationwide registry (The Japan Renal Biopsy Registry, J-RBR). Outcomes and predictors in the elderly (≥ 65 years) and non-elderly groups were identified. RESULTS: Similar clinical characteristics were observed in JNSCS patients and J-RBR patients (n = 1808). At the early stage of 1 month, 84.1% of patients were treated with immunosuppressive therapies. No significant differences were observed in therapies between age groups. However, elderly patients achieved complete remission (CR) more frequently than non-elderly patients, particularly those treated with therapies that included corticosteroids. No significant differences were noted in serum creatinine (sCr) elevations at 50 or 100%, end-stage kidney disease, or all-cause mortality between age groups. Corticosteroids were identified as an independent predictor of CR (HR 2.749, 95%CI 1.593-4.745, p = 0.000) in the multivariate Cox's model. sCr levels, hemoglobin levels, immunosuppressants, clinical remission, and relapse after CR were independent predictors of sCr × 1.5 or × 2.0. CONCLUSION: Early immunosuppressive therapy including corticosteroids for primary MN showed better remission rates in elderly patients in a nationwide cohort study.

Incidence of remission and relapse of proteinuria, end-stage kidney disease, mortality, and major outcomes in primary nephrotic syndrome: the Japan Nephrotic Syndrome Cohort Study (JNSCS).

BACKGROUND: Despite recent advances in immunosuppressive therapy for patients with primary nephrotic syndrome, its effectiveness and safety have not been fully studied in recent nationwide real-world clinical data in Japan. METHODS: A 5-year cohort study, the Japan Nephrotic Syndrome Cohort Study, enrolled 374 patients with primary nephrotic syndrome in 55 hospitals in Japan, including 155, 148, 38, and 33 patients with minimal change disease (MCD), membranous nephropathy (MN), focal segmental glomerulosclerosis (FSGS), and other glomerulonephritides, respectively. The incidence rates of remission and relapse of proteinuria, 50% and 100% increases in serum creatinine, end-stage kidney disease (ESKD), all-cause mortality, and other major adverse outcomes were compared among glomerulonephritides using the Log-rank test. Incidence of hospitalization for infection, the most common cause of mortality, was compared using a multivariable-adjusted Cox proportional hazard model. RESULTS: Immunosuppressive therapy was administered in 339 (90.6%) patients. The cumulative probabilities of complete remission within 3 years of the baseline visit was ≥ 0.75 in patients with MCD, MN, and FSGS (0.95, 0.77, and 0.79, respectively). Diabetes was the most common adverse events associated with immunosuppressive therapy (incidence rate, 71.0 per 1000 person-years). All-cause mortality (15.6 per 1000 person-years), mainly infection-related mortality (47.8%), was more common than ESKD (8.9 per 1000 person-years), especially in patients with MCD and MN. MCD was significantly associated with hospitalization for infection than MN. CONCLUSIONS: Patients with MCD and MN had a higher mortality, especially infection-related mortality, than ESKD. Nephrologists should pay more attention to infections in patients with primary nephrotic syndrome.

Upregulation of transient receptor potential melastatin 6 channel expression by rosiglitazone and all-trans-retinoic acid in erlotinib-treated renal tubular epithelial cells.

Anti-epidermal growth factor receptor (EGFR) drugs including erlotinib cause a side effect of hypomagnesemia. In lung adenocarcinoma A549 cells, anticancer agents such as cisplatin and doxorubicin dose-dependently increased toxicity, but the effects were significantly suppressed by culturing the cells in low Mg2+ -containing media. To obtain the maximum effect in cancer chemotherapy, it should be necessary to prevent the reduction of body Mg 2+ content. Anti-EGFR drugs inhibit EGF-induced elevation of transient receptor potential melastatin 6 (TRPM6) Mg 2+ channel in renal tubular epithelial NRK-52E cells. Here, we found that rosiglitazone, an antidiabetic drug, and all- trans-retinoic acid (ATRA), a vitamin A derivative, increase the messenger RNA (mRNA) level of TRPM6 in the presence of erlotinib. The rosiglitazone- and ATRA-induced elevation of mRNA level, Mg 2+ influx, and promoter activity of TRPM6 were inhibited by GW-9662, a potent antagonist of peroxisome proliferator-activated receptor (PPAR)γ, and LE135, a retinoic acid receptor (RAR) antagonist, respectively. Rosiglitazone increased the phosphorylation and nuclear localization levels of PPARγ, which were inhibited by GW-9662. In contrast, RAR was mainly distributed in the nuclei under control conditions, which was unchanged by ATRA and LE135. The promoter activity of TRPM6 was inhibited by a mutation in the peroxisome proliferator hormone response element (PPRE). A chromatin immunoprecipitation assay revealed that PPARγ and RAR bind to the PPRE, which was blocked by GW-9662 and LE135, respectively. These results suggest that rosiglitazone and ATRA reverse the reduction in Mg 2+ reabsorption caused by anti-EGFR drugs.

The RING finger- and PDZ domain-containing protein PDZRN3 controls localization of the Mg2+ regulator claudin-16 in renal tube epithelial cells.

Ion exchange in the renal tubules is fundamental to the maintenance of physiological ion levels. Claudin-16 (CLDN16) regulates the paracellular reabsorption of Mg2+ in the thick ascending limb of Henle's loop in the kidney, with dephosphorylation of CLDN16 increasing its intracellular distribution and decreasing paracellular Mg2+ permeability. CLDN16 is located in the tight junctions, but the mechanism regulating its localization is unclear. Using yeast two-hybrid systems, we found that CLDN16 binds to PDZRN3, a protein containing both RING-finger and PDZ domains. We also observed that the carboxyl terminus of the cytoplasmic CLDN16 region was required for PDZRN3 binding. PZDRN3 was mainly distributed in the cytosol of rat kidney cells and upon cell treatment with the protein kinase A inhibitor H-89, colocalized with CLDN16. H-89 also increased mono-ubiquitination and the association of CLDN16 with PDZRN3. Mono-ubiquitination levels of a K275A mutant were lower, and its association with PDZRN3 was reduced compared with wild-type (WT) CLDN16 and a K261A mutant, indicating that Lys-275 is the major ubiquitination site. An S217A mutant, a dephosphorylated form of CLDN16, localized to the cytosol along with PDZRN3 and the endosomal marker Rab7. PDZRN3 siRNA increased cell-surface localization of WT CLDN16 in H-89-treated cells or containing the S217A mutant and also suppressed CLDN16 endocytosis. Of note, H-89 decreased paracellular Mg2+ flux in WT CLDN16 cells, and PDZRN3 siRNA increased Mg2+ flux in the H-89-treated WT CLDN16 and S217A mutant cells. These results suggest that PDZRN3 mediates endocytosis of dephosphorylated CLDN16 and represents an important component of the CLDN16-trafficking machinery in the kidney.

The renoprotective effect and safety of a DPP-4 inhibitor, sitagliptin, at a small dose in type 2 diabetic patients with a renal dysfunction when changed from other DPP-4 inhibitors: REAL trial.

BACKGROUND: We conducted the multicenter, prospective, open-label study in type 2 diabetic (T2DM) patients with renal dysfunction, to clarify the efficacy and the safety in relation to renal function and glycemic control, and the economic effect when other dipeptidyl peptidase-4 (DPP-4) inhibitors were switched to a small dose of sitagliptin depending on their renal function. METHODS: Vildagliptin, alogliptin, or linagliptin received for more than 2 months were changed to sitagliptin at 25 or 12.5 mg/day depending on their renal function in 49 T2DMs. Renal function and glycemic control, and the drug cost were assessed during 6 months. RESULTS: Estimated glomerular filtration rate was not changed in patients not on hemodialysis (n = 29). The HbA1c levels were not altered in all of the patients including those on hemodialysis (n = 20). The active glucagon-like peptide-1 levels or other renal parameters were not altered significantly. There were no adverse events to be related to the drugs. The daily drug expense was reduced by 88.1 yen per patient. CONCLUSION: Switching to a small dose of sitagliptin according to the renal function in T2DM patients with renal dysfunction demonstrated the same efficacy and safety as those with other full-dose DPP-4 inhibitors, indicating a therapeutic option with a high cost performance.

Regional variations in immunosuppressive therapy in patients with primary nephrotic syndrome: the Japan nephrotic syndrome cohort study.

BACKGROUND: The lack of high-quality clinical evidences hindered broad consensus on optimal therapies for primary nephrotic syndromes. The aim of the present study was to compare prevalence of immunosuppressive drug use in patients with primary nephrotic syndrome across 6 regions in Japan. METHODS: Between 2009 and 2010, 380 patients with primary nephrotic syndrome in 56 hospitals were enrolled in a prospective cohort study [Japan Nephrotic Syndrome Cohort Study (JNSCS)], including 141, 151, and 38 adult patients with minimal change disease (MCD), membranous nephropathy (MN), and focal segmental glomerulosclerosis (FSGS), respectively. Their clinical characteristics were compared with those of patients registered in a large nationwide registry of kidney biopsies [Japan Renal Biopsy Registry (J-RBR)]. The regional prevalence of use of each immunosuppressive drug was assessed among adult MCD, MN, and FSGS patients who underwent immunosuppressive therapy in the JNSCS (n = 139, 127, and 34, respectively). Predictors of its use were identified using multivariable-adjusted logistic regression models. RESULTS: The clinical characteristics of JNSCS patients were comparable to those of J-RBR patients, suggesting that the JNSCS included the representatives in the J-RBR. The secondary major immunosuppressive drugs were intravenous methylprednisolone [n = 33 (24.6%), 24 (19.7%), and 9 (28.1%) in MCD, MN, and FSGS, respectively] and cyclosporine [n = 25 (18.7%), 62 (50.8%), and 16 (50.0%), respectively]. The region was identified as a significant predictor of use of intravenous methylprednisolone in MCD and MN patients. CONCLUSION: Use of intravenous methylprednisolone for MCD and MN differed geographically in Japan. Its efficacy should be further evaluated in a well-designed trial.

Up-Regulation of Transient Receptor Potential Melastatin 6 Channel Expression by Tumor Necrosis Factor-α in the Presence of Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitor.

Anti-epidermal growth factor receptor (EGFR) drugs such as erlotinib and gefitinib cause a side effect of hypomagnesemia, but chemotherapy to treat this has not yet been developed. The transient receptor potential melastatin 6 (TRPM6) channel is involved in the reabsorption of Mg2+ in the renal tubule. We reported previously that the expression of TRPM6 is up-regulated by epidermal growth factor (EGF) in renal tubular epithelial NRK-52E and HEK293 cells. EGF-induced elevation of TRPM6 expression was inhibited by erlotinib, gefitinib, and lapatinib. We found that tumor necrosis factor-α (TNF-α) increases TRPM6 expression in the presence of erlotinib. Therefore, we investigated what molecules are involved in the up-regulation of TRPM6 expression by TNF-α. EGF increased the levels of phosphorylated extracellular signal-regulated kinase 1 and 2 (p-ERK1/2), which were inhibited by erlotinib. TNF-α did not change p-ERK1/2 levels, but increased the phosphorylation and nuclear localization of nuclear factor-κB (NF-κB), which were blocked by the NF-κB inhibitors BAY 11-7082 and pyrrolidinedithiocarbamate ammonium. Similarly, luciferase reporter activity of human TRPM6 was increased by TNF-α, which was blocked by NF-κB inhibitors, and was inhibited by a mutation in the κB-binding site in the proximal region of the TRPM6 promoter. A chromatin immunoprecipitation assay revealed that NF-κB binds to the κB-binding site, which was blocked by NF-κB inhibitors. In the presence of erlotinib, TNF-α increased Mg2+ influx, which was blocked by NF-κB inhibitors. These results suggest that TNF-α reverses the reduction in Mg2+ reabsorption caused by anti-EGFR drugs. J. Cell. Physiol. 232: 2841-2850, 2017. © 2016 Wiley Periodicals, Inc.

Tight junctional localization of claudin-16 is regulated by syntaxin 8 in renal tubular epithelial cells.

Claudin-16 (CLDN16) regulates the paracellular reabsorption of Mg(2+) in the thick ascending limb of Henle's loop. However, the mechanism regulating the tight junctional localization of CLDN16 remains unknown. In yeast two-hybrid systems, we found that CLDN16 bound to syntaxin 8 (STX8), a target soluble N-ethylmaleimide-sensitive factor attachment protein receptor. We have examined the effect of STX8 on the localization and function of CLDN16 using Madin-Darby canine kidney cells expressing FLAG-tagged CLDN16. A pulldown assay showed that the carboxyl cytoplasmic region of human CLDN16 bound to STX8. CLDN16 was localized in the thick ascending limb, whereas STX8 was widely distributed throughout the rat kidney. An association between CLDN16 and STX8 was observed in rat renal homogenates and Madin-Darby canine kidney cells. STX8 siRNA decreased the cell surface localization of CLDN16 and transepithelial electrical resistance and permeability to Mg(2+) but increased the co-localization of CLDN16 with early endosome and lysosome markers. Dephosphorylation of CLDN16 by protein kinase A inhibitors and S217A mutant, a dephosphorylated form, decreased the association with STX8 and the cell surface localization of CLDN16. Recycling assays indicated that STX8 siRNA decreased the trafficking of CLDN16 to the plasma membrane without affecting endocytosis. Dominant negative Rab11 and recycling inhibitor primaquine decreased the cell surface localization of CLDN16, which was similar to that in STX8 siRNA-transfected cells. These results suggest that STX8 mediates the recycling of CLDN16 and constitutes an important component of the CLDN16 trafficking machinery in the kidney.

Downregulation of transient receptor potential M6 channels as a cause of hypermagnesiuric hypomagnesemia in obese type 2 diabetic rats.

We assessed the expression profile of Mg(2+)-transporting molecules in obese diabetic rats as a cause of hypermagnesiuric hypomagnesemia, which is involved in the development of insulin resistance, hypertension, and coronary diseases. Kidneys were obtained from male Otsuka Long-Evans Tokushima fatty (OLETF) and Long-Evans Tokushima Otsuka (LETO) obese diabetic rats at the ages of 16, 24, and 34 wk. Expression profiles were studied by real-time PCR and immunohistochemistry together with measurements of urine Mg(2+) excretion. Urine Mg(2+) excretion was increased in 24-wk-old OLETF rats and hypomagnesemia was apparent in 34-wk-old OLETF rats but not in LETO rats (urine Mg(2+) excretion: 0.16 ± 0.01 µg·min(-1)·g body wt(-1) in 24-wk-old LETO rats and 0.28 ± 0.01 µg·min(-1)·g body wt(-1) in 24-wk-old OLETF rats). Gene expression of transient receptor potential (TRP)M6 was downregulated (85.5 ± 5.6% in 34-wk-old LETO rats and 63.0 ± 3.5% in 34-wk-old OLETF rats) concomitant with Na(+)-Cl(-) cotransporter downregulation, whereas the expression of claudin-16 in tight junctions of the thick ascending limb of Henle was not different. The results of the semiquantitative analysis of immunohistochemistry were consistent with these findings (TRPM6: 0.49 ± 0.04% in 16-wk-old LETO rats, 0.10 ± 0.01% in 16-wk-old OLETF rats, 0.52 ± 0.03% in 24-wk-old LETO rats, 0.10 ± 0.01% in 24-wk-old OLETF rats, 0.48 ± 0.02% in 34-wk-old LETO rats, and 0.12 ± 0.02% in 34-wk-old OLETF rats). Gene expression of fibrosis-related proinflammatory cytokines as well as histological changes showed that the hypermagnesiuria-related molecular changes and tubulointerstitial nephropathy developed independently. TRPM6, located principally in distal convoluted tubules, appears to be a susceptible molecule that causes hypermagnesiuric hypomagnesemia as a tubulointerstitial nephropathy-independent altered tubular function in diabetic nephropathy.

Clinical significance of fractional magnesium excretion (FEMg) as a predictor of interstitial nephropathy and its correlation with conventional parameters.

BACKGROUND: Elevated urine Mg excretion and its correlation with histological damage in tubulo-interstitial nephropathy (TIN) were reported. Here we investigated the clinical significance of the fractional excretion of Mg (FEMg) for the prediction of TIN. METHODS: We enrolled and assessed 94 adult patients with various renal diseases diagnosed principally by renal biopsy. RESULTS: Our stratified analysis based on the value of the conventional TIN parameter N-acetylglucosaminidase (NAG) excretion showed that the high-NAG index group (more than median value of NAG-to-Cr ratio, n = 47) demonstrated significantly high FEMg values (p = 0.017). A univariate analysis revealed a significant correlation between the FEMg and the NAG index (R = 0.60) but not for other parameters. A multivariate regression analysis confirmed the significance of the FEMg as an effective predictor of the NAG index. The FEMg showed a significant correlation with the estimated glomerular filtration rate (eGFR) in the patients with eGFR ≤ 30 mL/min. The correlation of FEMg with the NAG index was not observed in the primary glomerulonephritis patients but was apparent in the patients with hypertensive nephrosclerosis or interstitial nephritis. CONCLUSION: Our findings may indicate that the combination of the FEMg and the NAG index can provide a specific, sensitive assessment for TIN in patients without renal insufficiency.

Adrenomedullin in peritoneal effluent expressed by peritoneal mesothelial cells.

BACKGROUND: Adrenomedullin (AM) possesses vasodilative and cell-protective properties. Glycine combines with the C-terminal of AM to form mature, physiologically active AM (mAM). AM is reportedly induced by high glucose condition in vascular endothelial or smooth muscle cells; however, little is known on how AM is activated by amidation. To investigate the behavior of AM in patients undergoing peritoneal dialysis (PD), the concentrations of AM, mAM and CA125 were measured. The mAM to AM ratio (mAM/AM ratio) was also evaluated as a marker of amidation activity. METHODS: Twenty patients were recruited for this study. The effluent at the time of the peritoneal equilibration test was collected and AM, mAM and CA125 concentrations were measured. The expression of AM in peritoneal mesothelial cells (PMCs) collected from effluent was also examined with an indirect immunofluorescent method. RESULTS: Mean values of AM and mAM in effluent were 18.1 ± 1.6 and 4.1 ± 0.3 fmol/mL, respectively. In plasma, they were 42.6 ± 3.3 and 5.6 ± 0.6 fmol/mL, respectively. AM concentrations in effluent did not correlate with plasma AM level but correlated well with the dialysate-to-plasma ratio of creatinine (D/P ratio of creatinine). Moreover, in 7 of 20 cases, concentrations of the mAM and mAM/AM ratio in effluent were higher than in plasma. In effluent, AM concentration but not the mAM/AM ratio correlated with CA125 concentration. Immunocytological study revealed diffuse, cytoplasmic expression of AM in PMCs which were collected from effluent during PD. CONCLUSION: AM is expressed by PMCs and actively amidated in the abdominal cavity of patients undergoing PD.

Potential Utility of Urinary Follistatin as a Non-Invasive Indicator of Acute Tubular Damage in Patients with Acute Kidney Injury.

Activin A is known to impede tubular repair following renal ischemia, whereas exogenous follistatin, an activin A antagonist, has been shown to ameliorate kidney damage in rats. Despite these findings, the precise role of endogenous follistatin in the kidney has yet to be elucidated. In this study, we investigated the localization of follistatin in the normal human kidney and its potential utility as a marker for acute kidney injury (AKI). In a total of 118 AKI patients and 16 healthy adults, follistatin levels in serum and urine were quantified using ELISA, and correlations with clinical parameters were analyzed. Follistatin-producing cells were positive for Na-Cl co-transporter and uromodulin, but negative for aquaporin 1 and aquaporin 2. Unlike healthy adults, urinary follistatin significantly increased in AKI patients, correlating positively with AKI severity. Urinary follistatin levels were notably higher in patients needing renal replacement therapy. Significant correlations were observed with urinary protein, α1 microglobulin, and urinary NGAL, but not with urinary KIM-1, urinary L-FABP, urinary NAG, urinary ß2 microglobulin, or serum creatinine. Interestingly, no correlation between urinary and serum follistatin levels was identified, indicating a renal origin for urinary follistatin. In conclusion, follistatin, produced by distal tubules, is detectable in the urine of AKI patients, suggesting its potential as a valuable marker for monitoring acute tubular damage severity in AKI.

Multiple electrolytes imbalances in a patient with inflammatory bowel disease associated with vitamin D deficiency: a case report.

BACKGROUND: Inflammatory bowel disease involves chronic inflammation and ulceration, primarily Crohn's disease and ulcerative colitis. The prevalence of inflammatory bowel disease is rising in industrialized countries. We describe the case of a patient with inflammatory bowel disease and multiple electrolyte disturbances that emphasize the link between a vitamin D deficiency and electrolyte imbalances. CASE: An 86-year-old Japanese man with severe hypocalcemia, hypophosphatemia, hypokalemia, and hypomagnesemia was referred to the gastroenterology and hepatology department our university hospital for severe diarrhea and abdominal pain. Based on clinical symptoms and biochemical and endoscopic findings, Crohn's disease, intestinal Behçet's disease, and intestinal tuberculosis were considered as differential diagnoses, but a final diagnosis was not reached. Prednisolone, azathioprine, and metronidazole were administered, and no apparent electrolyte abnormality was observed at the patient's admission to our hospital. On the 80th hospital day, marked hypocalcemia, hypophosphatemia, hypokalemia, and hypomagnesemia were noted and prolonged, despite daily supplementation with Ca and inorganic P. At his consultation with our department, we observed decreased fractional excretion of Ca, tubular reabsorption of phosphate, fractional excretion of K, and fractional excretion of Mg, suggesting the depletion of vitamin D and extrarenal wasting of K and Mg. The patient's serum Ca and inorganic P were quickly elevated in response to treatment with an active form of vitamin D, and his serum levels of K and Mg were restored to the normal range by an intravenous administration of K and Mg. A vitamin D deficiency is not rare in inflammatory bowel disease and is caused primarily by the decreased intestinal absorption of vitamin D. In the management of electrolyte imbalances in patients with inflammatory bowel disease, clinicians must consider the possible development of vitamin D deficiency-related disorders. CONCLUSION: Vitamin D deficiency in entero-Behçet's disease leads to severe hypocalcemia and hypophosphatemia, highlighting the importance of awareness in management.

A Case of Castleman's Disease with a Marked Infiltration of IgG4-Positive Cells in the Renal Interstitium.

Multicentric Castleman's disease (MCD) is a benign lymphoproliferative disorder with heterogenous clinical symptoms, and involves systemic organs in addition to lymph nodes. Herein, we present the case of a 55-year-old man with MCD characterized by an extensive infiltration of IgG4+ plasma cells in the kidneys. The patient presented to our hospital with a high fever and diarrhea. On admission, laboratory analysis revealed anemia, renal dysfunction (eGFR 30 mL/min/1.73 m2), polyclonal gammopathy (IgG 7130 mg/dL), elevated serum IgG4 level (2130 mg/dL), and increased C-reactive protein (8.0 mg/dL). An enlargement of lymph nodes in the axillary, mediastinal, para-aortic, and inguinal regions was observed on abdominal computed tomography. Axillary lymph node biopsy revealed interfollicular expansion due to dense plasma cell infiltration. Renal biopsy demonstrated significant plasma cell infiltration into the tubulointerstitium. Immunohistochemical analysis showed a 40% IgG4-positive/IgG-positive plasma cell ratio, meeting the diagnostic criteria for an IgG4-related disease. Amyloid A deposition was observed along vessel walls, and immunofluorescence analysis indicated granular positivity of IgG and C3 along the glomerular capillary wall. Elevated levels of interleukin-6 (21 pg/mL) and vascular endothelial growth factor (VEGF; 1210 pg/mL) were noted. Based on these findings, and the histological finding of the lymph node biopsy, idiopathic MCD was diagnosed. Corticosteroid monotherapy was only partially effective. Subsequently, tocilizumab administration was initiated, leading to sustained remission, even after discontinuation of prednisolone. Due to the diverse responses to steroid therapy and the varying prognoses observed in MCD and IgG4-related disease, it is essential to carefully diagnose MCD by thoroughly assessing the organ distribution of the disease, its response to steroid therapy, and any additional pathological findings.

Release from glomerular overload by the addition of low-dose thiazide in patients with angiotensin receptor blocker-resistant hypertension.

BACKGROUND/AIMS: This multicenter, prospective, observational study assessed the renoprotective effects of losartan/thiazide combination therapy in terms of lowering the estimated glomerular filtration rate (eGFR). METHODS: Adult patients with angiotensin receptor blocker (ARB)-resistant essential hypertension (n = 104) were enrolled and switched to combination therapy with losartan (50 mg/day) and hydrochlorothiazide (12.5 mg/day). RESULTS: eGFR values declined significantly during the first 3 months, and changes in eGFR were assessed according to tertiles of the eGFR decrease ratio at 3 months. Only the high eGFR decrease (1st tertile) group showed significantly greater decreases in baseline eGFR and albumin-to-creatinine ratio (ACR) during the first 3 months. Additionally, the assessment according to tertiles of the baseline eGFR showed a signifcant decrease in eGFR and ACR during the first 3 months in the high baseline eGFR (1st tertile) group, but not in the moderate (2nd tertile) and low baseline eGFR (3rd tertile) groups. CONCLUSION: The present results revealed that losartan/thiazide combination therapy attenuated glomerular overload, indicating that this therapy may provide glomerular protection in patients with an elevated GFR without causing prolonged damage to renal function.

Tubule-Derived Follistatin Is Increased in the Urine of Rats with Renal Ischemia and Reflects the Severity of Acute Tubular Damage.

Activin A, a member of the TGF-beta superfamily, is a negative regulator of tubular regeneration after renal ischemia. Activin action is controlled by an endogenous antagonist, follistatin. However, the role of follistatin in the kidney is not fully understood. In the present study, we examined the expression and localization of follistatin in normal and ischemic rat kidneys and measured urinary follistatin in rats with renal ischemia to assess whether urinary follistatin could serve as a biomarker for acute kidney injury. Using vascular clamps, renal ischemia was induced for 45 min in 8-week-old male Wistar rats. In normal kidneys, follistatin was localized in distal tubules of the cortex. In contrast, in ischemic kidneys, follistatin was localized in distal tubules of both the cortex and outer medulla. Follistatin mRNA was mainly present in the descending limb of Henle of the outer medulla in normal kidneys but was upregulated in the descending limb of Henle of both the outer and inner medulla after renal ischemia. Urinary follistatin, which was undetectable in normal rats, was significantly increased in ischemic rats and peaked 24 h after reperfusion. There was no correlation between urinary follistatin and serum follistatin. Urinary follistatin levels were increased according to ischemic duration and were significantly correlated with the follistatin-positive area as well as the acute tubular damage area. These results suggest that follistatin normally produced by renal tubules increases and becomes detectable in urine after renal ischemia. Urinary follistatin might be useful to assess the severity of acute tubular damage.

Long-term survival by surgery and adjuvant chemotherapy in a patient with perforated extranodal NK/T-cell lymphoma of the small intestine: a retrospective case study.

BACKGROUND: Extranodal natural killer/T-cell lymphoma, nasal type (ENKL) of the small intestine, is a disease with extremely poor prognosis. We describe treatment in a case which is novel in that it demonstrated long-term survival. CASE PRESENTATION: A 68-year-old man was admitted to the emergency department of our hospital with the complaint of severe umbilical pain with tenderness and muscular defense. An abdominal computed tomography scan revealed a thick-wall mass on the small intestine and intra-abdominal free air. He was suspected of perforation of a small intestinal tumor and underwent emergency surgery. The surgery revealed a perforated tumor ulcer, and ENKL was diagnosed from the postoperative pathological findings. The patient's postoperative course was uneventful. He was further treated with adjuvant chemotherapy by hematologist comprising six courses of dexamethasone, etoposide, ifosfamide, and carboplatin. The patient demonstrated long-term survival and was in remission at the time of writing, four years and five months after surgery. CONCLUSIONS: We report a rare case of long-term survival of perforated ENKL of the small intestine achieved by surgery and adjuvant chemotherapy with dexamethasone, etoposide, ifosfamide, and carboplatin. It is essential to consult with a hematologist to determine the most appropriate chemotherapy such as DeVIC if one encounters rare postoperative pathological findings of ENKL. To elucidate the pathophysiology of this disease and to prolong survival of affected patients, accumulation of cases of long-term survival and examination of associated characteristics is necessary.

Renoprotective effect of pioglitazone by the prevention of glomerular hyperfiltration through the possible restoration of altered macula densa signaling in rats with type 2 diabetic nephropathy.

BACKGROUND/AIMS: Pioglitazone (PGZ), one of the thiazolidinediones, has been known to show renoprotective effects. In this study, we focused on the effect of PGZ on glomerular hyperfiltration (GHF), resultant glomerular injury and altered macula densa signaling as a cause of sustained GHF through modified tubuloglomerular feedback in rats with diabetic nephropathy. METHODS: Kidneys from 24-week-old male OLETF rats and LET rats, nondiabetic controls, were used for the experiment. PGZ was administered (10 mg/kg/day, p.o.) for 2 weeks from 22 to 24 weeks of age in some of the OLETF rats (OLETF+PGZ). RESULTS: Parameters relating GHF, kidney weight, creatinine clearance, urine albumin/creatinine ratio and glomerular surface were all increased in OLETF rats and partially restored in OLETF+PGZ rats. Expressions of desmin and TGF-ß were also increased in OLETF rats and restored in OLETF+PGZ rats. The changes in TGF-ß expression were confirmed to be independent of podocyte number. Finally, the immunoreactivity of neuronal nitric oxide synthase (nNOS) and cyclooxygenase 2 (COX-2) in the macula densa was assessed for the evaluation of macula densa signaling. Altered intensities of nNOS and COX-2 in OLETF rats were restored in OLETF+PGZ rats, which agreed with the gene expression analysis (nNOS: 100.2 ± 2.9% in LET, 64.2 ± 2.7% in OLETF, 87.4 ± 12.1% in OLETF+PGZ; COX-2: 100.8 ± 7.4% in LET, 249.2 ± 19.4% in OLETF, 179.9 ± 13.5% in OLETF+PGZ; n = 5) and the semiquantitative analysis of nNOS/COX-2-positive cells. CONCLUSION: PGZ effectively attenuated the GHF and hyperfiltration-associated glomerular injury in diabetic nephropathy. The restoration of altered macula densa signaling might be involved in the renoprotective effect of PGZ.

Correlation between albuminuria and interstitial injury marker reductions associated with SGLT2 inhibitor treatment in diabetic patients with renal dysfunction.

BACKGROUND: We investigated the effects of sodium-glucose cotransporter 2 inhibitor (SGLT2i) administration focusing on its involvement in tubulo-interstitial disorders in diabetic kidney. METHODS: Enrolled patients with diabetic kidney disease received a mean dose of 52.3 mg of an SGLT2i (ipragliflozin) daily. Blood and urine were sampled at 0, 1, and 12 months (M). RESULTS: Non-renal-dysfunction patients (NRD: baseline eGFR ≥ 60 mL/min/1.73 m2, n = 12) and renal-dysfunction patients (RD: baseline eGFR < 60 mL/min/1.73 m2, n = 9) were analyzed separately. The median urine albumin-to-Cr ratio (ACR) was significantly decreased at 1 M in both groups (NRD: 163.1 at 0 M vs 118.5 mg/g Cr at 1 M, RD: 325.2 at 0 M vs 136.0 mg/g Cr at 1 M). In the RD, but not the NRD group, reduction of urine monocyte chemotactic protein-1 (MCP-1) by SGLT2i showed a significant difference between high-responders (HR: - 25.7 ± 11.4%) and low-responders (LR: 59.2 ± 17.0%), defined by ACR reduction at 1 M. Univariate analysis showed a significant correlation between the reduction of ACR and MCP-1 (R = 0.683, p = 0.042) in RD. CONCLUSION: SGLT2i exerted an anti-albuminuric effect regardless of the presence/absence of renal dysfunction. However, the anti-albuminuric effect of SGLT2i in patients with renal dysfunction appears more closely associated with amelioration of tubulo-interstitial disorders compared to patients without renal dysfunction.