Gemcitabine alters sialic acid binding of the glycocalyx and induces inflammatory cytokine production in cultured endothelial cells.

Gemcitabine (GEM) is an anticancer drug inhibiting DNA synthesis. Glomerular thrombotic microangiopathy (TMA) has been reported as an adverse effect. However, the precise mechanism of GEM-induced endothelial injury remains unknown. Cultured human umbilical vein endothelial cells (HUVECs) in the confluent phase were exposed to GEM (5-100 µM) for 48 h and evaluated cell viability and morphology, lectin binding concerning sialic acid of endothelial glycocalyx (GCX), and immunofluorescent staining of platelet-endothelial cell adhesion molecule (PECAM) and vascular endothelial growth factor receptor 2 (VEGFR2). The mRNA expression of α2,6-sialyltransferase (ST6Gal1), sialidase (neuraminidase-1: NEU-1), and interleukin (IL)-1ß and IL-6 was also evaluated. GEM exposure at 5 µM induced cellular shrinkage and intercellular dissociation, accompanied by slight attenuation of PECAM and VEGFR2 immunostaining, although cell viability was still preserved. At this concentration, lectin binding showed a reduction of terminal sialic acids in endothelial GCX, probably associated with reduced ST6Gal1 mRNA expression. IL-1ß and IL-6 mRNA expression was significantly increased after GEM exposure. GEM reduced terminal sialic acids in endothelial GCX through mRNA suppression of ST6Gal1 and induced inflammatory cytokine production in HUVECs. This phenomenon could be associated with the mechanism of GEM-induced TMA.

Crohn's disease may promote inflammation in IgA nephropathy: a case-control study of patients undergoing kidney biopsy.

Intestinal immunity has been closely associated with the pathogenesis and progression of renal diseases, a relationship known as the "gut-kidney axis." To determine the association between immunoglobulin A nephropathy (IgAN) and Crohn's disease (CD), a clinico-pathological study was performed on patients who had IgAN with CD (CD-IgAN) and without CD (NOS-IgAN). We enrolled 29 patients diagnosed with IgAN via renal biopsy at the Tokyo Yamate Medical Center from 2009 to 2017. The patients were divided into CD-IgAN (n = 18) and NOS-IgAN (n = 11) and evaluated for clinical and pathological findings. IgA subclasses and galactose-deficient IgA1 (Gd-IgA1) were examined via immunohistochemistry using formalin-fixed paraffin-embedded sections from renal biopsy. Our results showed no significant difference in the extent of mesangial IgA subclasses or Gd-IgA1 deposition according to the presence or absence of CD. Pathologically, however, those with CD-IgAN had remarkably higher percentage of global glomerulosclerosis and extent of interstitial fibrosis and tubular atrophy (IF/TA) compared to those with NOS-IgAN. Moreover, the extent of macrophage infiltration in the glomerulus and interstitium was significantly higher in CD-IgAN than in NOS-IgAN. Clinically, the CD-IgAN group had significantly worse responsiveness to steroid treatment compared to the NOS-IgAN group. In conclusion, the similar immunological characteristics of deposited IgA molecules in the glomeruli between the CD-IgAN and NOS-IgAN groups might suggest their etiological similarity. However, a renal pathology showing advanced glomerular and tubulointerstitial sclerosis accompanying increased macrophage infiltration and highly resistant clinical features in patients with CD-IgAN suggests that some pathophysiological factors in CD, including abnormal intestinal immunity, may promote and activate the inflammatory process in IgAN via undetermined mechanisms.

Crescentic IgA nephropathy after administration of human monoclonal interleukin-12/23p40 antibody in a patient with Crohn's disease: a case report.

Ustekinumab (UST), an interleukin (IL)-12/IL-23-blocking monoclonal antibody, is a novel therapeutic option for Crohn's disease (CD). We describe a 24-year-old man with CD who showed an abrupt decline in renal function after administration of UST. Twenty-nine months previously, the patient was diagnosed with CD, and abnormal urinalysis findings in health checkup were coincidentally found at that time. Three months previously, treatment for CD was switched from infliximab to UST because of therapy-resistant severe diarrhea and bloody stools. A single dose of UST (260 mg) was initially intravenously administered, followed by single subcutaneous administration (90 mg) 2 months later. Thereafter, the patient exhibited rapid renal dysfunction with significant urinary abnormalities, although his gastrointestinal symptoms had completely disappeared. He was admitted to our hospital for further examination and treatment. Renal pathologic findings were compatible with crescentic glomerulonephritis consisting of almost fibro-cellular crescents. Immunofluorescent study showed IgA and C3 deposition in the glomerular mesangial area and IgA subclass staining revealed predominant IgA1 with concomitant mild IgA2 deposition. Furthermore, galactose-deficient IgA1 (Gd-IgA1) was also positive in the mesangial area. In addition, serum-Gd-IgA1 level was moderately increased. UST treatment was stopped and he responded to intensive steroid therapy with a parallel reduction of serum creatinine and Gd-IgA1 levels without flare of gastrointestinal symptoms. To our knowledge, this is the first case of immunoglobulin A nephropathy (IgAN) in patient with CD that might be aggravated by UST treatment. We presume that inhibition of IL-12/23 signaling with UST may cause to form crescentic IgAN by enhancing Gd-IgA1 production.

Hemophagocytic Syndrome-Associated Variant of Methotrexate-Associated Intravascular Large B-Cell Lymphoma in a Rheumatoid Arthritis Patient.

A 59-year-old man was treated for rheumatoid arthritis (RA) for 12 years with methotrexate (MTX) and prednisolone. After MTX-associated interstitial pneumonia developed, he was treated with cyclophosphamide and prednisolone for 7 months. Arthritis worsened, and tacrolimus was added to the treatment regimen. One month later, he had fever, loss of appetite, and dyspnea on exertion. Blood tests showed pancytopenia with large, atypical lymphocytes. Computed tomography showed mild splenomegaly. Bone marrow examination demonstrated CD20-positive, EBER-positive atypical lymphocytes, and hemophagocytosis. Random skin biopsy led to the diagnosis of intravascular large B-cell lymphoma (IVLBCL). The final diagnosis was a hemophagocytic syndrome-associated variant of IVLBCL. Complete remission was achieved after seven courses of R-CHOP. However, within a month, he complained of dizziness. Magnetic resonance imaging revealed focal infarctions in the cerebellum and around the left lateral ventricle. Central nervous system relapse was suspected. Although salvage chemotherapy (CHASER), whole brain irradiation, and intrathecal injection of cytarabine and prednisolone were temporarily effective, he died. Autopsy revealed infiltration of lymphoma cells in the brain and adrenal glands. To the best of our knowledge, this is the sixth case of IVLBCL and the first case of the hemophagocytic syndrome-associated variant of IVLBCL in RA patients in the literature.

The effect of small dose of topiroxostat on serum uric acid in patients receiving hemodialysis.

INTRODUCTION: Topiroxostat, a recently developed xanthine oxidase inhibitor, is expected to have fewer adverse effects than allopurinol because it has different mechanism of action from alloprinol. However, its dosage, usage and safety have not been established in patients with impaired renal function or those undergoing dialysis at the development since no studies was conducted in these patients. METHODS: Cross over clinical trial using 3 months of allopurinol and topiroxostat on 27 maintain Japanese HD patients were carried out. The effects on oxidative stress status of both drugs were also evaluated by measuring oxidation reduction potential. FINDINGS: Twenty-five of twenty-seven patients completed study. The mean serum uric acid levels in the topiroxostat-treated arm was significantly lower than it in the allopurinol-treated arm time-dependently (P < 0.0001). Corrected oxidative stress ratio defined as biological antioxidant potential/diacron reactive oxygen metabolites was significantly increased in topiroxostat-arm (*P = 0.0035), but not in allopurinol-arm (P = 0.1429). No significant difference was seen in diacron reactive oxygen metabolites, biological antioxidant potential, static oxidation-reduction potential, and capacity oxidation-reduction potential between pre and post treatment of both drugs. DISCUSSION: It is suggested that a low dose of topiroxostat decreased serum uric acid sufficiently to maintain it below 7.0 mg/dL in patients receiving hemodialysis.

Photoinduced acceleration of the effluent rate of developing solvents in azobenzene-tethered silica gel.

The switching of a molecular length of azobenzene between its trans and cis forms by photoirradiation originates various photoresponsive systems in the molecular level and/or nanolevel. Recently, we and another group separately reported that some azobenzene-modified mesoporous silicas remarkably promote the release of molecules from the inside of the mesopore to the outside, when the lights, both UV and visible lights, were irradiated simultaneously. In these cases, the release rates of molecules were enhanced by the impeller-like effect of molecular motion of azobenzene moiety attributed to the continuous photoisomerization between the trans and cis isomers. This paper presents that azobenzene-substituent-tethered amorphous silica gel could promote the development of solvents in chromatography systems by photoirradiation. In column chromatography system where azobenzene-tethered silica gel was packed, the irradiation of both UV and visible lights increased the effluent rate of the developing solvents. The single irradiation of UV light scarcely enhanced the rate, while the visible light irradiation longer than 400 nm in wavelength also accelerated the development of the solvent moderately. The same kinds of phenomena were observed when this photopromoted chromatography system was applied to thin layer chromatography (TLC). Hydrocarbon developing solvents in the regions, where UV and visible lights were irradiated, moved up the TLC plate higher than those without photoirradiation. When the pyrene solution in the developing solvent was utilized in the chromatography systems, the similar photoacceleration of pyrene development was observed at the same level as the developing solvents.