High-Dose Acetaminophen with N-acetylcysteine Rescue Inhibits M2 Polarization of Tumor-Associated Macrophages.

High-dose acetaminophen (AAP) with N-acetylcysteine (NAC) rescue is among the few treatments that has shown activity in phase I trials without achieving dose-limiting toxicity that has not progressed to evaluation in later line studies. While the anti-tumor effects of AAP/NAC appear not to be mediated by glutathione depletion and free radical injury, the mechanism of anti-tumor effects of AAP/NAC has not been definitively characterized. In vitro, the effects of AAP/NAC were evaluated on bone marrow derived macrophages. Effects of AAP on IL-4/STAT6 (M2) or IFN/LPS/STAT1 (M1) signaling and downstream gene and protein expression were studied. NAC reversed the AAP toxicity in the normal liver but did not reverse AAP cytotoxicity against tumor cells in vitro. AAP/NAC selectively inhibited IL-4-induced STAT6 phosphorylation but not IFN/LPS-induced STAT1 phosphorylation. Downstream, AAP/NAC inhibited IL-4 induction of M2-associated genes and proteins but did not inhibit the IFN/LPS induction of M1-associated genes and proteins. In vivo, AAP/NAC inhibited tumor growth in EF43.fgf4 and 4T1 triple-negative breast tumors. Flow cytometry of tumor-associated macrophages revealed that AAP/NAC selectively inhibited M2 polarization. The anti-tumor activity of high-dose AAP/NAC is lost in macrophage-depleted mouse syngeneic tumor models, suggesting a macrophage-dependent mechanism of action. In conclusion, our study is the first to show that high-dose AAP/NAC has profound effects on the tumor immune microenvironment that facilitates immune-mediated inhibition of tumor growth.

Repurposing Ferumoxytol as a Breast Cancer-Associated Macrophage Tracer with Five-Dimensional Quantitative [Fe]MRI of SPION Dynamics.

Tumor-associated macrophages (TAMs) in breast cancer regulate inflammation, immunosuppression, angiogenesis, and metastasis. However, TAM imaging remains a clinical challenge. Ferumoxytol has long been an FDA-approved superparamagnetic iron oxide nanoparticle (SPION) preparation used as an intravenous (IV) treatment for iron-deficiency anemia. Given its high transverse relaxivity, ferumoxytol produces a negative image contrast upon cellular uptake in T2-weighted magnetic resonance imaging (MRI) studies. Here we evaluated ferumoxytol as a contrast agent to image/quantify TAMs in an aggressive mouse model of breast cancer: We developed [Fe]MRI to measure the 5-dimensional function c(x,y,z,t), where c is the concentration of nanoparticle iron and {x,y,z,t} is the 4-dimensional set of tumor space-time coordinates. Ferumoxytol SPIONs are readily phagocytosed (~104/cell) by the F4/80+CD11b+ TAMs within breast tumors. Quantitative [Fe]MRIs served to determine both the spatial and the temporal distribution of the SPION iron, and hence to measure [Fe] = c(x,y,z,t), a surrogate for TAM density. In single-dose pharmacokinetic studies, after an IV dose of 5 mg/Kg iron, [Fe]MRI measurements showed that c(x,y,z,t) within breast tumors peaked around [Fe] = 70 µM at 42 h post-administration, and decayed below the [Fe]MRI detection limit (~2 µM) by day 7. There was no SPION uptake in control organs (muscle and adipose tissue). Optical microscopy of tissue sections confirmed that F4/80+CD11b+ TAMs infiltrated the tumors and accumulated SPION iron. Our methodology and findings have translational applications for breast cancer patients.

High dose acetaminophen inhibits STAT3 and has free radical independent anti-cancer stem cell activity.

High-dose acetaminophen (AAP) with delayed rescue using n-acetylcysteine (NAC), the FDA-approved antidote to AAP overdose, has demonstrated promising antitumor efficacy in early phase clinical trials. However, the mechanism of action (MOA) of AAP's anticancer effects remains elusive. Using clinically relevant AAP concentrations, we evaluated cancer stem cell (CSC) phenotype in vitro and in vivo in lung cancer and melanoma cells with diverse driver mutations. Associated mechanisms were also studied. Our results demonstrated that AAP inhibited 3D spheroid formation, self-renewal, and expression of CSC markers when human cancer cells were grown in serum-free CSC media. Similarly, anti-CSC activity was demonstrated in vivo in xenograft models - tumor formation following in vitro treatment and ex-vivo spheroid formation following in vivo treatment. Intriguingly, NAC, used to mitigate AAP's liver toxicity, did not rescue cells from AAP's anti-CSC effects, and AAP failed to reduce glutathione levels in tumor xenograft in contrast to mice liver tissue suggesting nonglutathione-related MOA. In fact, AAP mediates its anti-CSC effect via inhibition of STAT3. AAP directly binds to STAT3 with an affinity in the low micromolar range and a high degree of specificity for STAT3 relative to STAT1. These findings have high immediate translational significance concerning advancing AAP with NAC rescue to selectively rescue hepatotoxicity while inhibiting CSCs. The novel mechanism of selective STAT3 inhibition has implications for developing rational anticancer combinations and better patient selection (predictive biomarkers) for clinical studies and developing novel selective STAT3 inhibitors using AAP's molecular scaffold.

Enhancing antitumor immunity through checkpoint blockade as a therapeutic strategy in T-cell lymphomas.

The majority of historical therapies for managing T-cell lymphomas (TCLs) have consisted of T-cell-depleting strategies. Unfortunately, these forms of therapies can hamper the ability to mount effective antitumor immune responses. Recently, the use of checkpoint inhibitors has revolutionized the therapy of solid and hematologic malignancies. The development of immunotherapies for the management of TCL has lagged behind other malignancies given 2 central reasons: (1) the competing balance of depleting malignant T cells while simultaneously enhancing an antitumor T-cell response and (2) concern for tumor hyperprogression by blocking inhibitory signals on the surface of the malignant T cell, thereby leading to further proliferation of the malignant cells. These challenges were highlighted with the discovery that programmed cell death protein 1 (PD-1) functions paradoxically as a haploinsufficient tumor suppressor in preclinical TCL models. In contrast, some preclinical and clinical evidence suggests that PD-1/programmed death ligand 1 may become an important therapeutic tool in the management of patients with TCL. Improved understanding of the immune landscape of TCL is necessary in order to identify subsets of patients most likely to benefit from checkpoint-inhibitor therapy. With increased preclinical research focus on the tumor microenvironment, substantial strides are being made in understanding how to harness the power of the immune system to treat TCLs. In this review, designed to be a "call to action," we discuss the challenges and opportunities of using immune-modulating therapies, with a focus on checkpoint inhibitors, for the treatment of patients with TCL.

Cancer cell-intrinsic expression of MHC II in lung cancer cell lines is actively restricted by MEK/ERK signaling and epigenetic mechanisms.

BACKGROUND: Programmed death 1/programmed death ligand 1 (PD-1/PD-L1) targeted immunotherapy affords clinical benefit in ~20% of unselected patients with lung cancer. The factor(s) that determine whether a tumor responds or fails to respond to immunotherapy remains an active area of investigation. We have previously defined divergent responsiveness of two KRAS-mutant cell lines to PD-1/PD-L1 blockade using an orthotopic, immunocompetent mouse model. Responsiveness to PD-1/PD-L1 checkpoint blockade correlates with an interferon gamma (IFNγ)-inducible gene signature and major histocompatibility complex class II (MHC II) expression by cancer cells. In the current study, we aim to identify therapeutic targets that can be manipulated in order to enhance cancer-cell-specific MHC II expression. METHODS: Responsiveness to IFNγ and induction of MHC II expression was assessed after various treatment conditions in mouse and human non-small cell lung cancer (NSCLC) cell lines using mass cytometric and flow cytometric analysis. RESULTS: Single-cell analysis using mass and flow cytometry demonstrated that IFNγ consistently induced PD-L1 and MHC class I (MHC I) across multiple murine and human NSCLC cell lines. In contrast, MHC II showed highly variable induction following IFNγ treatment both between lines and within lines. In mouse models of NSCLC, MHC II induction was inversely correlated with basal levels of phosphorylated extracellular signal-regulated kinase (ERK) 1/2, suggesting potential mitogen-activated protein (MAP) kinase-dependent antagonism of MHC II expression. To test this, cell lines were subjected to varying levels of stimulation with IFNγ, and assessed for MHC II expression in the presence or absence of mitogen-activated protein kinase kinase (MEK) inhibitors. IFNγ treatment in the presence of MEK inhibitors significantly enhanced MHC II induction across multiple lung cancer lines, with minimal impact on expression of either PD-L1 or MHC I. Inhibition of histone deacetylases (HDACs) also enhanced MHC II expression to a more modest extent. Combined MEK and HDAC inhibition led to greater MHC II expression than either treatment alone. CONCLUSIONS: These studies emphasize the active inhibitory role that epigenetic and ERK signaling cascades have in restricting cancer cell-intrinsic MHC II expression in NSCLC, and suggest that combinatorial blockade of these pathways may engender new responsiveness to checkpoint therapies.

Cancer Cell-Intrinsic Expression of MHC Class II Regulates the Immune Microenvironment and Response to Anti-PD-1 Therapy in Lung Adenocarcinoma.

MHC class II (MHCII) expression is usually restricted to APC but can be expressed by cancer cells. We examined the effect of cancer cell-specific MHCII (csMHCII) expression in lung adenocarcinoma on T cell recruitment to tumors and response to anti-PD-1 therapy using two orthotopic immunocompetent murine models of non-small cell lung cancer: CMT167 (CMT) and Lewis lung carcinoma (LLC). We previously showed that CMT167 tumors are eradicated by anti-PD1 therapy, whereas LLC tumors are resistant. RNA sequencing analysis of cancer cells recovered from tumors revealed that csMHCII correlated with response to anti-PD1 therapy, with immunotherapy-sensitive CMT167 cells being csMHCII positive, whereas resistant LLC cells were csMHCII negative. To test the functional effects of csMHCII, MHCII expression was altered on the cancer cells through loss- and gain-of-function of CIITA, a master regulator of the MHCII pathway. Loss of CIITA in CMT167 decreased csMHCII and converted tumors from anti-PD-1 sensitive to anti-PD-1 resistant. This was associated with lower levels of Th1 cytokines, decreased T cell infiltration, increased B cell numbers, and decreased macrophage recruitment. Conversely, overexpression of CIITA in LLC cells resulted in csMHCII in vitro and in vivo. Enforced expression of CIITA increased T cell infiltration and sensitized tumors to anti-PD-1 therapy. csMHCII expression was also examined in a subset of surgically resected human lung adenocarcinomas by multispectral imaging, which provided a survival benefit and positively correlated with T cell infiltration. These studies demonstrate a functional role for csMHCII in regulating T cell infiltration and sensitivity to anti-PD-1.

Tumor-intrinsic response to IFNγ shapes the tumor microenvironment and anti-PD-1 response in NSCLC.

Targeting PD-1/PD-L1 is only effective in ∼20% of lung cancer patients, but determinants of this response are poorly defined. We previously observed differential responses of two murine K-Ras-mutant lung cancer cell lines to anti-PD-1 therapy: CMT167 tumors were eliminated, whereas Lewis Lung Carcinoma (LLC) tumors were resistant. The goal of this study was to define mechanism(s) mediating this difference. RNA sequencing analysis of cancer cells recovered from lung tumors revealed that CMT167 cells induced an IFNγ signature that was blunted in LLC cells. Silencing Ifngr1 in CMT167 resulted in tumors resistant to IFNγ and anti-PD-1 therapy. Conversely, LLC cells had high basal expression of SOCS1, an inhibitor of IFNγ. Silencing Socs1 increased response to IFNγ in vitro and sensitized tumors to anti-PD-1. This was associated with a reshaped tumor microenvironment, characterized by enhanced T cell infiltration and enrichment of PD-L1hi myeloid cells. These studies demonstrate that targeted enhancement of tumor-intrinsic IFNγ signaling can induce a cascade of changes associated with increased therapeutic vulnerability.

Targeted overexpression of prostacyclin synthase inhibits lung tumor progression by recruiting CD4+ T lymphocytes in tumors that express MHC class II.

Lung-specific overexpression of prostacyclin synthase (PGIS) decreases tumor initiation in murine lung cancer models. Prostacyclin analogs prevent lung tumor formation in mice and reverse bronchial dysplasia in former smokers. However, the effect of prostacyclin on lung cancer progression has not been well studied. We investigated the effects of pulmonary PGIS overexpression in an orthotopic immunocompetent mouse model of lung cancer using two murine lung cancer cell lines. Pulmonary PGIS overexpression significantly inhibited CMT167 lung tumor growth, increased CXCL9 expression, and increased CD4+ tumor-infiltrating lymphocytes. Immunodepletion of CD4+ T cells abolished the inhibitory effect of pulmonary PGIS overexpression on CMT167 lung tumor growth. In contrast, pulmonary PGIS overexpression failed to inhibit growth of a second murine lung cancer cell line, Lewis Lung Carcinoma (LLC) cells, and failed to increase CXCL9 expression or CD4+ T lymphocytes in LLC lung tumors. Transcriptome profiling of CMT167 cells and LLC cells recovered from tumor-bearing mice demonstrated that in vivo, CMT167 cells but not LLC cells express MHC class II genes and cofactors necessary for MHC class II processing and presentation. These data demonstrate that prostacyclin can inhibit lung cancer progression and suggest that prostacyclin analogs may serve as novel immunomodulatory agents in a subset of lung cancer patients. Moreover, expression of MHC Class II by lung cancer cells may represent a biomarker for response to prostacyclin.

Complement Activation via a C3a Receptor Pathway Alters CD4+ T Lymphocytes and Mediates Lung Cancer Progression.

The complement cascade is a part of the innate immune system that acts primarily to remove pathogens and injured cells. However, complement activation is also peculiarly associated with tumor progression. Here we report mechanistic insights into this association in multiple immunocompetent orthotopic models of lung cancer. After tumor engraftment, we observed systemic activation of the complement cascade as reflected by elevated levels of the key regulator C3a. Notably, growth of primary tumors and metastases was both strongly inhibited in C3-deficient mice (C3-/- mice), with tumors undetectable in many subjects. Growth inhibition was associated with increased numbers of IFNγ+/TNFα+/IL10+ CD4+ and CD8+ T cells. Immunodepletion of CD4+ but not CD8+ T cells in tumor-bearing subjects reversed the inhibitory effects of C3 deletion. Similarly, antagonists of the C3a or C5a receptors inhibited tumor growth. Investigations using multiple tumor cell lines in the orthotopic model suggested the involvement of a C3/C3 receptor autocrine signaling loop in regulating tumor growth. Overall, our findings offer functional evidence that complement activation serves as a critical immunomodulator in lung cancer progression, acting to drive immune escape via a C3/C5-dependent pathway.Significance: This provocative study suggests that inhibiting complement activation may heighten immunotherapeutic responses in lung cancer, offering findings with immediate implications, given the existing clinical availability of complement antagonists. Cancer Res; 78(1); 143-56. ©2017 AACR.

Current and potential imaging applications of ferumoxytol for magnetic resonance imaging.

Contrast-enhanced magnetic resonance imaging is a commonly used diagnostic tool. Compared with standard gadolinium-based contrast agents, ferumoxytol (Feraheme, AMAG Pharmaceuticals, Waltham, MA), used as an alternative contrast medium, is feasible in patients with impaired renal function. Other attractive imaging features of i.v. ferumoxytol include a prolonged blood pool phase and delayed intracellular uptake. With its unique pharmacologic, metabolic, and imaging properties, ferumoxytol may play a crucial role in future magnetic resonance imaging of the central nervous system, various organs outside the central nervous system, and the cardiovascular system. Preclinical and clinical studies have demonstrated the overall safety and effectiveness of this novel contrast agent, with rarely occurring anaphylactoid reactions. The purpose of this review is to describe the general and organ-specific properties of ferumoxytol, as well as the advantages and potential pitfalls associated with its use in magnetic resonance imaging. To more fully demonstrate the applications of ferumoxytol throughout the body, an imaging atlas was created and is available online as supplementary material.

Iron-based superparamagnetic nanoparticle contrast agents for MRI of infection and inflammation.

OBJECTIVE. In this article, we summarize the progress to date on the use of superparamagnetic iron oxide nanoparticles (SPIONs) as contrast agents for MRI of inflammatory processes. CONCLUSION. Phagocytosis by macrophages of injected SPIONs results in a prolonged shortening of both T2 and T2* leading to hypointensity of macrophage-infiltrated tissues in contrast-enhanced MR images. SPIONs as contrast agents are therefore useful for the in vivo MRI detection of macrophage infiltration, and there is substantial research and clinical interest in the use of SPION-based contrast agents for MRI of infection and inflammation. This technique has been used to identify active infection in patients with septic arthritis and osteomyelitis; importantly, the MRI signal intensity of the tissue has been found to return to its unenhanced value on successful treatment of the infection. In SPION contrast-enhanced MRI of vascular inflammation, animal studies have shown decreased macrophage uptake in atherosclerotic plaques after treatment with statin drugs. Human studies have shown that both coronary and carotid plaques that take up SPIONs are more prone to rupture and that abdominal aneurysms with increased SPION uptake are more likely to grow. Studies of patients with multiple sclerosis suggest that MRI using SPIONs may have increased sensitivity over gadolinium for plaque detection. Finally, SPIONs have enabled the tracking and imaging of transplanted stem cells in a recipient host.

Incidence of Pneumocystis jirovecii pneumonia after temozolomide for CNS malignancies without prophylaxis.

AIMS: Prophylaxis against Pneumocystis jiroveci pneumonia (PJP) is currently recommended for patients receiving chemoradiation with temozolomide for newly diagnosed glioblastoma multiforme. At our institution, PJP prophylaxis during temozolomide treatment has not been routinely given because of the paucity of supporting data. We investigated the rate of PJP infections in our patients. PATIENTS & METHODS: We conducted a retrospective chart review of 240 brain tumor patients treated between 1999 and 2012 with temozolomide and no PJP prophylaxis, 127 of which received concurrent chemoradiation. RESULTS: One in 240 patients (0.4%; 95% CI: 0.01-2.00; median total dose: 7375 mg/m(2); interquartile range: 1300) were diagnosed with PJP. CONCLUSION: There was a <1% rate of PJP for brain tumor patients treated with temozolomide until progression without PJP prophylaxis.

Preclinical high-dose acetaminophen with N-acetylcysteine rescue enhances the efficacy of cisplatin chemotherapy in atypical teratoid rhabdoid tumors.

BACKGROUND: Atypical teratoid rhabdoid tumors (AT-RT) are pediatric tumors of the central nervous system with limited treatment options and poor survival rate. We investigated whether enhancing chemotherapy toxicity by depleting intracellular glutathione (GSH; a key molecule in cisplatin resistance) with high dose acetaminophen (AAP), may improve therapeutic efficacy in AT-RT in vitro. PROCEDURE: BT16 (cisplatin-resistant) and BT12 (cisplatin-sensitive) AT-RT cell lines were treated with combinations of AAP, cisplatin, and the anti-oxidant N-acetylcysteine (NAC). Cell viability, GSH and peroxide concentrations, mitochondrial damage, and apoptosis were evaluated in vitro. RESULTS: AAP enhanced cisplatin cytotoxicity in cisplatin-resistant BT16 cells but not cisplatin-sensitive BT12 cells. Baseline GSH levels were elevated in BT16 cells compared to BT12 cells, and AAP decreased GSH to a greater magnitude in BT16 cells than BT12 cells. Unlike BT12 cells, BT16 cells did not have elevated peroxide levels upon treatment with cisplatin alone, but did have elevated levels when treated with AAP + cisplatin. Both cell lines had markedly increased mitochondrial injury when treated with AAP + cisplatin relative to either drug treatment alone. The enhanced toxic effects were partially reversed with concurrent administration of NAC. CONCLUSIONS: Our results suggest that AAP could be used as a chemo-enhancement agent to potentiate cisplatin chemotherapeutic efficacy particularly in cisplatin-resistant AT-RT tumors with high GSH levels in clinical settings.

Primary dystonia misinterpreted as Parkinson disease: Video case presentation and practical clues.

Diagnosing dystonia can be challenging and depends on the recognition of subtle clinical signs. Due to clinical heterogeneity, variable age at presentation, and overlapping features with other disorders, dystonia is under-recognized. The presence of dystonic tremor is often a reason for misdiagnosis. We report an illustrative case of a patient with DYT1 dystonia who was originally misdiagnosed with Parkinson disease. Careful physical examination and history-taking can reveal dystonia and prompt appropriate diagnostic studies, which, in turn, can lead to potentially life-changing treatment. Our report illustrates typical challenges in the recognition and diagnosis of dystonia, and serves to increase clinicians' awareness of this disabling, but treatable, condition.

Acetaminophen enhances cisplatin- and paclitaxel-mediated cytotoxicity to SKOV3 human ovarian carcinoma.

BACKGROUND: Ovarian cancer is commonly treated with cisplatin/paclitaxel but many tumors become resistant. Acetaminophen reduced glutathione and enhanced chemotherapy efficacy in hepatic cancer treatment. The objective of this study was to examine if acetaminophen enhances the cytotoxicity of cisplatin/paclitaxel in ovarian cancer. MATERIALS AND METHODS: SKOV3 human ovarian carcinoma cells in vitro and a subcutaneous tumor nude rat model were used and treated with cisplatin/paclitaxel with or without acetaminophen. RESULTS: In vitro, acetaminophen enhanced apoptosis induced by cisplatin and paclitaxel with similar effects on glutathione, reactive oxygen species and mitochondrial membrane potential, but different effects on nuclear factor erythroid 2-related factor 2 (NRF2) translocation. In vivo, acetaminophen was uniformly distributed in tissues and significantly reduced hepatic glutathione. Acetaminophen enhanced the cisplatin chemotherapeutic effect by reducing tumor recurrence. CONCLUSION: Our results suggest that acetaminophen as a chemoenhancing adjuvant could improve the efficacy of cisplatin and paclitaxel in treating patients with ovarian carcinoma and other tumor types.

Atorvastatin improves tubular status in non-diabetic patients with chronic kidney disease - placebo controlled, randomized, cross-over study.

BACKGROUND: There is evidence that dyslipidemia is associated with chronic kidney disease (CKD) and it has been implicated in the progression of renal damage. Optimal management of dyslipidemia should therefore lead to renal benefits. A number of experimental models demonstrate a beneficial effect of statins in ameliorating renal damage. However, the exact mechanism by which statins protect against renal damage remains unclear. METHODS: In a placebo-controlled, randomized, cross-over study we evaluated the influence of atorvastatin (ATO) 40 mg/day added to the renin-angiotensin-aldosterone systeme (RAAS) blockade on proteinuria and surrogate biomarkers of tubular damage or injury in 14 non-diabetic patients with proteinuria (0.4-1.8 g per 24 h) with normal or declined kidney function (eGFR 55-153 ml/min). In the eight-week run-in period, therapy using angiotensin converting enzyme inhibitors (ACEI) and/or angiotensin II subtype 1 receptor antagonists (ARB) was adjusted to achieve a blood pressure below 130/80 mm Hg. Next, patients were randomly assigned to one of two treatment sequences: ATO/washout/placebo or placebo/washout/ATO. Clinical evaluation and laboratory tests were performed at the randomization point and after each period of the study. The primary end point of this study was a change in proteinuria measured as 24-h urine protein excretion (DPE). Secondary end points included urine N-acetyl-ß-D-glucosaminidase (NAG) and α1-microglobulin (α1m) excretion. RESULTS: The ATO therapy significantly reduced urine excretion of α1m (p=0.033) and NAG (p=0.038) as compared to placebo. There were no differences in proteinuria, blood pressure, eGFR and serum creatinine between the ATO and placebo groups. CONCLUSION: Atorvastatin treatment is safe and improves biomarkers of tubular damage or injury in non-diabetic patients with CKD.

The effect of N-acetylcysteine on blood pressure and markers of cardiovascular risk in non-diabetic patients with chronic kidney disease: a placebo-controlled, randomized, cross-over study.

BACKGROUND: Cardiovascular complications in patients with chronic kidney disease (CKD) are frequent. They show increased cardiovascular mortality and morbidity attributable to accumulation of several risk factors; e.g., hypertension, oxidative stress and elevated plasma homocysteine concentration. Despite recent progress in their management, there is still no optimal therapy that can stop progression of CKD and decrease cardiovascular outcome in these patients. Antioxidants, e.g., N-acetylcysteine (NAC), have been suggested as a promising medicament in this field. MATERIAL/METHODS: In a placebo-controlled, randomized, two-period cross-over study we evaluated the influence of eight weeks of NAC therapy (1200 mg/day) added to pharmacological renin-angiotensin system blockade on ambulatory blood pressure and surrogate markers of cardiovascular risk and injury in 20 non-diabetic patients with albuminuria [30-915 mg per creatinine mg] and normal or slightly decreased kidney function [eGFR 61-163 ml/min]. After eight weeks run-in period during which the therapy using angiotensin converting enzyme inhibitors and/or angiotensin receptor blockers was settled, patients were randomly assigned to one of two treatment sequences: NAC/washout/placebo or placebo/washout/NAC. RESULTS: No significant changes in blood pressure, albuminuria and homocysteine plasma level were observed. CONCLUSIONS: NAC had no effect on blood pressure and surrogate markers of cardiovascular injury in non-diabetic patients with CKD.

Effect of pentoxifylline on proteinuria, markers of tubular injury and oxidative stress in non-diabetic patients with chronic kidney disease - placebo controlled, randomized, cross-over study.

BACKGROUND: Inhibition of the renin-angiotensin-aldosterone system (RAAS) with angiotensin converting enzyme inhibitors (ACEI) and/or angiotensin II subtype 1 receptor antagonists (ARB) is a common strategy used in the management of patients with chronic kidney disease (CKD). However, there is no universal therapy that can stop progression of CKD. Pentoxifylline (PTE) is a non-specific phosphodiesterase inhibitor with anti-inflammatory properties. It has been reported to have promising effects in CKD treatment. METHODS: In a placebo-controlled, randomized, cross-over study we evaluated the influence of PTE (1200 mg/day) added to RAAS blockade on proteinuria, surrogate markers of tubular injury and oxidative stress-dependent products in 22 non-diabetic patients with proteinuria (0.4-4.3 g per 24 h) with normal or declined kidney function [eGFR 37-178 mL/min]. In an eight-week run-in period, therapy using ACEI and/or ARB was adjusted to achieve a blood pressure below 130/80 mm Hg. Next, patients were randomly assigned to one of two treatment sequences: PTE/washout/placebo or placebo/washout/PTE. Clinical evaluation and laboratory tests were performed at the randomization point and after each period of the study. RESULTS: The PTE therapy reduced proteinuria (by 26%) as compared to placebo. There were no differences in alpha(1)-microglobulin, urine excretion of N-acetyl-beta-d-glucosaminidase (NAG), hsCRP, the urinary excretion of 15-F(2)t-isoprostane, blood pressure (BP), eGFR and serum creatinine between the PTE and placebo groups. CONCLUSION: Pentoxifylline may decrease proteinuria in non-diabetic patients with CKD.