Relationship of Thyroid Function with Renal Hemodynamics and Cholesterol Metabolism in Proteinuric Kidney Disease: A Pilot Study.

Nephrotic syndrome and hypothyroidism are respectively reported to influence renal hemodynamics and hypercholesterolemia. However, the relationship of proteinuria-associated thyroid function with renal hemodynamics and cholesterol metabolism has yet to be determined in a simultaneous analysis of thyroid, renal, and cholesterol variables. We investigated the hypothesis that the changes in thyroid hormones by proteinuria may contribute to changes in cholesterol metabolism and renal hemodynamics by proteinuria. Twenty-nine patients (17 men and 12 women) with proteinuric kidney disease (mean age 46 years) were enrolled in a pilot study. Data for serum free triiodothyronine (FT3), free thyroxine (FT4), total cholesterol, and filtration fraction (FF; assessed by para-aminohippuric acid clearance) were used in variable-adjusted correlation analyses. The patients had the following data (mean ± standard deviation): urinary protein 5.18 ± 3.28 g/day, FT3 2.18 ± 0.44 pg/mL, FT4 1.03 ± 0.26 ng/dL, FF 0.27 ± 0.07, and total cholesterol 327 ± 127 mg/dL. There was a significant positive correlation of FT3 with FF (ß = 0.58, p = 0.01) and a significant inverse correlation of FT4 with total cholesterol (ß = -0.40, p = 0.01). A positive correlation of FT3 with FF and an inverse correlation of FT4 with total cholesterol were demonstrated in patients with proteinuric kidney disease. The proteinuria-associated reduction in serum thyroid hormone levels was correlated with hypercholesterolemia and the reduced glomerular FF. Further studies of these relationships are required.

A case of paraneoplastic IgA nephropathy with glomerular capillary IgA and galactose-deficient IgA1 deposition.

Paraneoplastic IgA nephropathy (IgAN) is an underrecognized condition in which malignancy manifests as symptoms of IgAN, and it remains controversial regarding their mechanistic relation between IgAN and malignancy. Herein, we report a case of a 68-year-old Japanese man with glottic cancer who developed nephrotic syndrome as a clinical manifestation of IgAN. Renal biopsy revealed diffuse proliferative glomerulonephritis with glomerular capillary IgA deposition that is a rare subtype of IgAN. After complete remission of the glottic cancer by irradiation, proteinuria and hematuria disappeared. Based on his clinical course, we diagnosed paraneoplastic IgAN. Therefore, we should consider the possibility that IgAN with glomerular capillary IgA deposition might be paraneoplastic glomerulopathy especially before initiating immunosuppressive therapy. The patient thereafter developed prostate cancer and hepatocellular cancer, but IgAN did not recur. The association of IgAN specifically with the glottic cancer in this triple-cancer patient may suggest a potential link between IgAN and mucosal cancer. Because galactose-deficient IgA1 (Gd-IgA1) was observed in the similar pattern as IgA, Gd-IgA1 also may play an important role in the pathogenesis of paraneoplastic IgAN.

Removal of calciprotein particles from the blood using an adsorption column improves prognosis of hemodialysis miniature pigs.

Hyperphosphatemia is a major risk for poor prognosis in patients with end-stage renal disease. However, the molecular mechanism behind this link remains elusive. We and others have demonstrated that serum phosphorus levels correlate positively with circulating levels of calciprotein particles (CPPs). CPPs are colloidal mineral-protein complexes containing insoluble calcium-phosphate precipitates and have been reported to induce calcification in cultured vascular smooth muscle cells and inflammatory responses in cultured macrophages. Hence, we hypothesize that CPPs may be responsible for disorders associated with hyperphosphatemia. Using hyperphosphatemic miniature pigs receiving hemodialysis, here we show that removal of CPPs from the blood with a newly developed CPP adsorption column improves survival and alleviates complications including coronary artery calcification, vascular endothelial dysfunction, metastatic pulmonary calcification, left ventricular hypertrophy, and chronic inflammation. The present study identifies CPPs as an effective therapeutic target and justifies clinical trials to determine whether the CPP adsorption column may be useful as a medical device for improving clinical outcomes of hemodialysis patients.

Paraoxonase 1 Activity and Renal Replacement Therapy for Chronic Renal Failure: A Meta-Analysis.

Chronic renal failure (CRF) is associated with the development of cardiovascular disease (CVD). Paraoxonase 1 (PON1), an antioxidant enzyme, shows cardioprotective properties and has been proposed as a therapeutic marker for CRF. A systematic analysis of the literature assessing the association between PON1 activity and renal replacement therapy (RRT) of CRF is currently lacking. Therefore, we set out to perform a meta-analysis of the available data on PON1 in RRT of CRF. We searched three electronic databases for studies on PON1 activity in CRF patients with RRT such as hemodialysis (HD), peritoneal dialysis (PD), or renal transplantation (RTx), published before June 2023. A random-effects and network meta-analysis were performed. A total of 53 studies were eligibly identified. Compared to CRF patients without RRT, RTx patients had higher paraoxonase activity (standard mean difference (SMD), 1.76, 95% confidence interval (CI), 0.76-2.75), followed by HD (SMD, 0.73; 95% CI, 0.02-1.45) and PD patients. Likewise, RTx patients had higher arylesterase activity (SMD, 1.84, 95% CI, 0.18-3.50), followed by HD and PD patients. Also, paraoxonase activity was increased after HD (SMD, 0.59, 95% CI, 0.16-1.03). In conclusion, the overall data demonstrated that PON1 activity is higher in CRF patients with RRT, particularly RTx, followed by that of HD and PD. Measuring PON1 activity can also be included to the paraclinical toolbox for the management of RRT, in addition to the understanding of CRF-related pathophysiology. Regarding the selection of RRT types and their potential to prevent CVD, more research is required.

The effects for inflammatory responses by CPP with different colloidal properties in hemodialysis patients.

Calciprotein particles (CPPs) are colloids composed of solid-phase calcium-phosphate and serum protein fetuin-A. CPPs form a polydispersed system with different particle size and density. CPPs with specific physical properties can induce calcification and innate immune responses in cultured cells. In hemodialysis patients, blood CPP levels were reported to correlate with vascular calcification and inflammation. However, little is known about relation between these disorders and physical properties of CPPs. Here, we show that the association between physical properties of plasma CPPs and serum levels of inflammatory cytokines/chemokines in 78 hemodialysis out-patients by cross-sectional study. Patients with cardiovascular disease (CVD) had significantly higher high density CPP (H-CPP) levels than patients without CVD but not low density CPP (L-CPP). Seven cytokines/chemokines (EGF, eotaxin, IL-8, IP-10, MCP-1, MIP-1, MIP-1ß and TNFα) were detectable in the serum samples from > 95% of the patients. In multivariate regression analysis, H-CPP was positively associated with eotaxin after adjusting for age, gender, smoking, serum phosphate and FGF23. L-CPP was negatively associated with IL-8 after adjusting for age, gender, serum albumin, phosphate and FGF23. High H-CPP levels were associated with pro-inflammatory response, whereas L-CPPs were associated with anti-inflammatory response. CPPs with different physical properties may impact differently on pathophysiology in HD patients.

Calcium phosphate microcrystals in the renal tubular fluid accelerate chronic kidney disease progression.

The Western pattern diet is rich not only in fat and calories but also in phosphate. The negative effects of excessive fat and calorie intake on health are widely known, but the potential harms of excessive phosphate intake are poorly recognized. Here, we show the mechanism by which dietary phosphate damages the kidney. When phosphate intake was excessive relative to the number of functioning nephrons, circulating levels of FGF23, a hormone that increases the excretion of phosphate per nephron, were increased to maintain phosphate homeostasis. FGF23 suppressed phosphate reabsorption in renal tubules and thus raised the phosphate concentration in the tubule fluid. Once it exceeded a threshold, microscopic particles containing calcium phosphate crystals appeared in the tubule lumen, which damaged tubule cells through binding to the TLR4 expressed on them. Persistent tubule damage induced interstitial fibrosis, reduced the number of nephrons, and further boosted FGF23 to trigger a deterioration spiral leading to progressive nephron loss. In humans, the progression of chronic kidney disease (CKD) ensued when serum FGF23 levels exceeded 53 pg/mL. The present study identified calcium phosphate particles in the renal tubular fluid as an effective therapeutic target to decelerate nephron loss during the course of aging and CKD progression.

Pulse wave velocity, carotid intima media thickness and flow-mediated dilation in Takayasu arteritis: a systematic review.

INTRODUCTION: Takayasu arteritis (TA) is a chronic vasculitis associated with an increased cardiovascular risk. The measurement of pulse wave velocity (PWV), carotid artery intima-media thickness (CIMT) and flow-mediated dilatation (FMD) are generally used for evaluating the cardiovascular risk. The application of these measurements to TA patients remains undetermined. MATERIAL AND METHODS: Clinical studies that reported the PWV, CIMT and FMD levels in TA patients, which were published prior to 2021, were summarized using PubMed. RESULTS: Fifteen studies were eligible. Overall, in TA patients, the PWV and CIMT levels were significantly higher and the FMD levels were significantly lower compared to controls. Part of the studies showed that the disease activity of TA was significantly associated with the PWV, CIMT or FMD levels. CONCLUSIONS: The PWV, CIMT and FMD measurements could be useful for evaluating the cardiovascular risk in TA patients. Further studies to determine the proper use of these measurements are warranted.

Low urine pH associated with sarcopenia in the elderly: A multi-center observational study.

ABSTRACT: The pathophysiology of sarcopenia is complex and must be further explored. While metabolic acidosis may be a risk factor for sarcopenia, it remains unclear whether acidic urine is related to sarcopenia. The purpose of the present study was to investigate the association between sarcopenia and urine pH in the elderly.An elderly population (n = 123 [male = 46]; mean age = 81.7 years) was classified into 2 groups based on the sarcopenia status according to their strength, requirement of assistance in walking, their ability to rise from a chair their ability to climb stairs, and their history of falls. Urinalysis was measured using dipstick tests.The sarcopenia group (n = 32) was significantly older, had less exercise habit and showed a lower urine pH (mean pH = 5.5) in comparison to the nonsarcopenia group (mean pH = 6.2, P < .01). A multivariate analysis that was adjusted for age, male sex, body mass index, uro-renal variables and exercise habit revealed that urine pH (odds ratio, 0.43; 95% confidence interval, 0.22-0.85, P = .02), age and less exercise habit were independently and significantly associated with sarcopenia.The findings of the present study suggest a potential association between metabolic acidosis and the pathophysiology of sarcopenia in the elderly. As urine pH is a simple biomarker that can be obtained using dipstick tests, it is therefore expected to be helpful for detecting sarcopenia in the clinical setting.

Calciprotein particles and fibroblast growth factor 23 contribute to the pathophysiology of hypercalcemia in a patient with renal sarcoidosis.

In patients with sarcoidosis, dysregulated calcium metabolism is one of the frequently observed complications. However, little attention has been paid to abnormal phosphate metabolism. Herein we present the case of a 42-year-old Japanese man with renal sarcoidosis who developed acute kidney injury due to hypercalcemia and nephrolithiasis. Laboratory data showed hypercalcemia with a normal serum phosphate level and high serum 1,25-hydroxyvitamin D3, fibroblast growth factor 23 (FGF23) and calciprotein particle (CPP) levels. After treatment with oral prednisone and bisphosphonate, the laboratory abnormalities and renal dysfunction were resolved. Thus increases in FGF23 and CPP may indicate disturbed phosphate metabolism in renal sarcoidosis.

Interleukin-36α as a potential biomarker for renal tubular damage induced by dietary phosphate load.

Excessive intake of phosphate has been known to induce renal tubular damage and interstitial inflammation, leading to acute kidney injury or chronic kidney disease in rodents and humans. However, sensitive and early biomarkers for phosphate-induced kidney damage remain to be identified. Our previous RNA sequencing analysis of renal gene expression identified interleukin-36α (IL-36α) as a gene significantly upregulated by dietary phosphate load in mice. To determine the time course and dose dependency of renal IL-36α expression induced by dietary phosphate load, we placed mice with or without uninephrectomy on a diet containing either 0.35%, 1.0%, 1.5%, or 2.0% inorganic phosphate for 10 days, 4 weeks, or 8 weeks and evaluated renal expression of IL-36α and other markers of tubular damage and inflammation by quantitative RT-PCR, immunoblot analysis, and immunohistochemistry. We found that IL-36α expression was induced in distal convoluted tubules and correlated with phosphate excretion per nephron. The increase in IL-36α expression was simultaneous with but more robust in amplitude than the increase in tubular damage markers such as Osteopontin and neutrophil gelatinase-associated lipocalin, preceding the increase in expression of other inflammatory cytokines, including transforming growth factor-α, interleukin-1ß, and transforming growth factor-ß1. We conclude that IL-36α serves as a marker that reflects the degree of phosphate load excreted per nephron and of associated kidney damage.

The Ratio of Oxidized Lipoprotein(a) to Native Lipoprotein(a) and the Endothelial Function in Patients with Type 2 Diabetes Mellitus.

The ratio of oxidized lipoprotein(a) to native lipoprotein(a) (oxLp(a)/Lp(a)) may be a reasonable index for assessing endothelial dysfunction in type 2 diabetes mellitus (T2DM). The present study investigated whether the oxLp(a)/Lp(a) level is correlated with the endothelial function using the Endo-PATTM, a newly developed device, in patients with T2DM. A total of 63 patients with T2DM (mean age: 59 years old) were enrolled in the study. The patients' serum Lp(a) and oxLp(a) levels were measured using an enzyme-linked immunosorbent assay. The reactive hyperemia index (RHI) level was measured using an Endo-PATTM 2000. A correlation analysis between the measured variables was conducted. Among the patients, the mean hemoglobin A1c was 7.8%. The median level of oxLp(a)/Lp(a) was 0.28 (interquartile range: 0.07-0.54), and the mean RHI was 1.8 (standard deviation: 0.4). In a multiple linear regression analysis, the oxLp(a)/Lp(a) level was an independent, significant, and inverse variable for the RHI level (ß = -0.26, p < 0.05), along with male gender. A high oxLp(a)/Lp(a) level may reflect endothelial dysfunction, as assessed by the Endo-PATTM, in patients with T2DM. Further studies are warranted to confirm the observed findings.

Multiple Sclerosis Drug Fingolimod Induces Thrombotic Microangiopathy in Deoxycorticosterone Acetate/Salt Hypertension.

We examined whether fingolimod (FTY720), an S1PR (sphingosine-1-phosphate receptor) modulator, has beneficial or harmful effects on mineralocorticoid/salt-induced renal injury. Uninephrectomized rats on 0.9% NaCl/0.3% KCl drinking solution were randomly divided into control, control+FTY720, deoxycorticosterone acetate (DOCA), and DOCA+FTY720 groups and administered vehicle, vehicle+FTY720, DOCA+vehicle, and DOCA+FTY720 for 4 weeks, respectively. Only the DOCA+FTY720 group had reduced survival rates and showed hemolysis because of intravascular mechanical fragmentation of erythrocytes and thrombocytopenia. Both the DOCA+FTY720 and DOCA groups developed malignant hypertension, which was more severe in the DOCA+FTY720 group. In the DOCA+FTY720 group only, thrombotic microangiopathy involving severe renal arteriole endothelial cell injury was observed and was characterized by fibrinoid necrosis and onion-skin lesions in arterioles. There were fewer circulating endothelial progenitor cells in the DOCA+FTY720 group but more in the DOCA group compared with the control group. Expression levels of VEGF (vascular endothelial growth factor), S1PR1, and S1PR3 in renal arteriole endothelial cells were significantly greater in the DOCA+FTY720 and DOCA groups compared with the control group, with levels being similar between the 2 groups. Expression levels of endothelial nitric oxide synthase in renal arteriole endothelial cells were significantly lower in the DOCA+FTY720 group only. The control+FTY720 group showed reduced circulating endothelial progenitor cells but no significant functional or pathological changes in kidneys or changes in blood pressure. Exposure of uninephrectomized rats to DOCA/salt+FTY720 for 4 weeks induced renal arteriolar endothelial cell injury, resulting in the development of thrombotic microangiopathy. Consideration of this possibility is recommended when prescribing FTY720.

Identification and quantification of plasma calciprotein particles with distinct physical properties in patients with chronic kidney disease.

Calciprotein particles (CPP) are solid-phase calcium-phosphate bound to serum protein fetuin-A and dispersed as colloids in the blood. Recent clinical studies indicated that serum CPP levels were increased with decline of renal function and associated with inflammation and vascular calcification. However, CPP assays used in these studies measured only a part of CPP over a certain particle size and density. Here we show that such CPP are mostly artifacts generated during processing of serum samples in vitro. The native CPP in fresh plasma are smaller in size and lower in density than those artifactual CPP, composed of fetuin-A carrying amorphous and/or crystalline calcium-phosphate, and increased primarily with serum phosphate levels. We have identified several physicochemical factors that promote aggregation/dissolution of CPP and transition of the calcium-phosphate from the amorphous phase to the crystalline phase in vitro, including addition of anti-coagulants, composition of buffer for sample dilution, the number of freeze-thaw cycles, the speed for sample freezing, and how many hours the samples were left at what temperature. Therefore, it is of critical importance to standardize these factors during sample preparation in clinical studies on CPP and to investigate the biological activity of the native CPP.

Performing Anticoagulation: A Puzzling Case of Cholesterol Embolization Syndrome.

The avoidance of any form of anticoagulation is advised in cases of cholesterol embolization syndrome (CES). We herein describe a case of CES in a man with a history of unprovoked pulmonary embolism for which warfarinization was performed. Despite anecdotal reports of successful anticoagulation in CES patients with certain indications, irreversible renal failure, which was sufficiently severe to require chronic hemodialysis, eventually developed in our patient. Our results emphasize the pitfalls of this procedure, which imply its limited feasibility and safety. Several therapeutic concerns associated with this case are also discussed.

Pulse Wave Velocity in Kawasaki Disease.

Kawasaki disease (KD) is an acute childhood febrile disease of unknown etiology. It exhibits not only coronary artery aneurysms in some cases but also systemic vasculitis. Whether KD is associated with accelerated atherosclerosis remains debatable. The measurement of pulse wave velocity (PWV) is useful as a simple, noninvasive measurement of arterial stiffness, an atherosclerotic manifestation. We herein present a systematic review of clinical studies that focused on PWV in patients with KD. A PubMed-based search identified 8 eligible studies published until June 2015. The PWV of patients with KD, regardless of antecedent coronary artery lesions, was high relative to controls, even though their blood pressure appeared to be similar. Although definitive conclusions cannot be made with the limited information, patients with KD may be at risk of systemic atherosclerosis in association with arterial stiffness. Further research, including longitudinal and outcome studies, is needed to determine the clinical significance of a potential increase in PWV in patients with KD.

[Acute Kidney Injury in a Patient with Diarrhea and Vomiting Undergoing Chemotherapy for Colorectal Cancer].

A case of acute kidney injury (AKI) strongly suspected to be drug-induced (oxaliplatin and non-steroidal anti-inflammatory drug) is discussed regarding the mechanism of a reduced glomerular filtration rate responsible for the development of AKI. Urinary biochemical tests are useful for the differential diagnosis of pre- renal (functional) AKI and intrinsic (structural) AKI(so-called acute tubular necrosis). In this case, although a comprehensive differential diagnosis using these parameters supported intrinsic AKI, only one pa- rameter, fractional excretion of urea (FEurea), indicated the existence of prerenal AKI. As a result of treatment with the appropriate management of body fluid in addition to avoiding nephrotoxic medications, AKI rapidly improved. FEurea revealed the underlying mechanism of AKI. [Review].

Henoch-Schönlein purpura complicated with severe gastrointestinal bleeding.

Bleeding from the gastrointestinal tract is one of the common determinants of morbidity and mortality in the ordinary clinical setting. The gastrointestinal involvement of Henoch-Schönlein purpura (HSP) has often been described as self-limiting, with no long-term morbidity. In this report, we describe our experience with a male HSP patient who presented with abdominal pain, loss of appetite and deteriorated renal function associated with nephrotic syndrome. Despite the use of aggressive immunomodulatory treatments, including corticosteroids and plasmapheresis, he developed lethal gastrointestinal hemorrhage. We believe that the accumulation of more experience with additional cases similar to ours is mandatory for the establishment of optimal management for HSP patients with severe gastrointestinal manifestations.

Purpura with ulcerative skin lesions and mixed cryoglobulinemia in a quiescent hepatitis B virus carrier.

Mixed cryoglobulinemia is occasionally seen in patients with hepatitis B virus (HBV) infection. This report presents the case of a quiescent HBV carrier who had type II mixed cryoglobulinemia, protracted purpura, ulcerative skin lesions and advanced chronic kidney disease. The cutaneous manifestations of the patient improved along with a decrease in the serum cryoglobulin and HBV-deoxyribonucleic acid levels following the initiation of oral entecavir in combination with plasmapheresis. However, the patient ultimately required prednisolone due to the limited benefits of these treatments. We also discuss various concerns regarding steroid treatment in patients with mixed cryoglobulinemia complicated by HBV infection.

The origin of idiopathic renal arteriovenous malformation with giant twin aneurysms.

A 50-year-old female patient who presented with intermittent gross hematuria was referred to our hospital. Three-dimensional computed tomography (3D-CT) revealed a left renal arteriovenous malformation (AVM). Because she declined to undergo additional therapy including surgical treatment, we observed the clinical course of renal AVM for 7 years using 3DCT. When the 3D-CT showed gradual enlargement of the aneurysms concurrent with the onset of clinical symptoms (cardiomegaly and hypertension), we performed simple left nephrectomy. After the operation, the cardiomegaly and hypertension returned to normal, and gross hematuria did not recur. Based on the macro-anatomical findings of the resected kidney and the observation of the natural course, this case strongly supported the hypothesis that the renal AVM had existed from birth and enlarged gradually to eventually produce the typical signs and symptoms.