A projected cost-utility analysis of avacopan for the treatment of antineutrophil cytoplasmic antibody-associated vasculitis in Spain

BACKGROUND

Antineutrophil cytoplasmic antibody-associated vasculitis (AAV) are rare autoimmune diseases characterized by inflammation of blood vessels. This study aimed to assess the cost-utility of avacopan in combination with rituximab (RTX) or cyclophosphamide (CYC) compared with glucocorticoids (GC) for the treatment of severe, active AAV in Spain.

METHODS

A 9-state Markov model was designed to reflect the induction of remission and sustained remission of AAV over a lifetime horizon. Clinical data and utility values were mainly obtained from the ADVOCATE trial, and costs (€ 2022) were sourced from national databases. Quality-adjusted life years (QALYs), and incremental cost-utility ratio (ICUR) were evaluated. An annual discount rate of 3% was applied. Sensitivity analyses were performed to examine the robustness of the results.

RESULTS

Avacopan yielded an increase in effectiveness (6.52 vs. 6.17 QALYs) and costs (€16,009) compared to GC, resulting in an ICUR of €45,638 per additional QALY gained. Avacopan was associated with a lower incidence of end-stage renal disease (ESRD), relapse and hospitalization-related adverse events. Sensitivity analyses suggested that the model outputs were robust and that the progression to ESRD was a driver of ICUR.

CONCLUSIONS

Avacopan is a cost-effective option for patients with severe, active AAV compared to GC in Spain.

Diagnosis and treatment of lupus nephritis: a summary of the Consensus Document of the Spanish Group for the Study of Glomerular Diseases (GLOSEN)

Lupus nephritis (LN) is the most frequent serious manifestation of patients with systemic lupus erythematosus (SLE). Up to 60% of SLE patients develop LN, which has a significant impact on their quality of life and prognosis. Recent advances have improved the diagnostic approach to LN, and new drugs that block specific pathways and kidney damage progression have been developed. Several randomized and well-powered clinical trials have confirmed the efficacy of these agents in terms of proteinuria remission and preservation of kidney function in the medium and long term, with an acceptable safety profile and good tolerance. The combination of different therapies allows for reduction of the dose and duration of corticosteroids and other potentially toxic therapies and leads to an increase in the number of patients achieving complete remission of the disease. This consensus document carried out by the Spanish Group for the Study of Glomerular Diseases (GLOSEN) provides practical and updated recommendations, based on the best available evidence and clinical expertise of participating nephrologists.

Pretransplant evaluation and the risk of glucose metabolic alterations after renal transplantation: a prospective study

BACKGROUND

Post-transplant prediabetes (PreDM) and diabetes (PTDM) are common and have an impact on cardiovascular events. We sought to investigate the pathogenesis and best approach for prediction.

METHODS

We prospectively studied 115 waitlisted patients from a single center without manifest diabetes. An oral glucose tolerance test (OGTT) was performed yearly until transplantation and 12 months later. Insulin secretion, insulin sensitivity (IS) and disposition index (DI) were derived from the OGTT.

RESULTS

PreDM and PTDM were observed in 27% and 28.6% of patients, respectively. Pretransplant age, body mass index (BMI), 120 min glucose, IS, DI, and prediabetes or undiagnosed diabetes were significantly associated with these alterations. In multivariate analysis, pretransplant age [odds ratio (OR) 1.5; 95% confidence interval (CI) 1.04-2.1], BMI (OR 1.16; 95% CI 1.04-1.3) and cumulative steroids (OR 1.5; 95% CI 1.02-2.2) were predictors of PreDM or PTDM. Receiver operating characteristic curve analysis showed that pretransplant BMI and 120 min glucose had the highest area under the curve (0.72; 95% CI 0.62-0.8; and 0.69; 95% CI 0.59-0.79, respectively). The highest discrimination cut-off for BMI (≥28.5 kg/m2) and 120 min glucose (≥123.5 mg/dL) yielded a similar number needed to diagnose (2.5).

CONCLUSIONS

PreDM or PTDM develops in waitlisted patients with an ineffective insulin secretion and BMI shows a similar diagnostic capacity to OGTT. Pretransplant interventions may reduce post-transplant glucose alterations.

Consensus document of the Spanish Group for the Study of the Glomerular Diseases (GLOSEN) for the diagnosis and treatment of lupus nephritis

A significant number of patients with systemic lupus erythematosus (between 20% and 60% according to different reported series) develop lupus nephritis in the course of its evolution, which directly influences their quality of life and vital prognosis. In recent years, the greater knowledge about the pathogenesis of systemic lupus and lupus nephritis has allowed relevant advances in the diagnostic approach and treatment of these patients, achieving the development of drugs specifically aimed at blocking key pathogenic pathways of the disease. Encouragingly, these immunomodulatory agents have shown in well-powered, randomized clinical trials good clinical efficacy in the medium-term, defined as proteinuria remission and preservation of kidney function, with an acceptable safety profile and good patient tolerability. All this has made it possible to reduce the use of corticosteroids and other potentially more toxic therapies, as well as to increase the use of combined therapies. The present consensus document carried out by the Glomerular Diseases Working Group of the Spanish Society of Nephrology (GLOSEN), collects in a practical and summarized, but rigorous way, the best currently available evidence about the diagnosis, treatment, and follow-up of lupus nephritis patients, including cases of special situations, with the main objective of providing updated information and well-founded clinical recommendations to treating physicians, to improve the diagnostic and therapeutic approach to our patients.

GCKIII (Germinal Center Kinase III) Kinases STK24 and STK25 (Serine/Threonine Kinase 24 and 25) Inhibit Cavernoma Development

BACKGROUND

Cavernous cerebral malformations can arise because of mutations in the CCM1, CCM2, or CCM3 genes, and lack of Cdc42 has also been reported to induce these malformations in mice. However, the role of the CCM3 (cerebral cavernous malformation 3)-associated kinases in cavernoma development is not known, and we, therefore, have investigated their role in the process.

METHODS

We used a combination of an in vivo approach, using mice genetically modified to be deficient in the CCM3-associated kinases STK24 and STK25 (serine/threonine kinases 24 and 25), and the in vitro model of human endothelial cells in which expression of STK24 and STK25 was inhibited by RNA interference.

RESULTS

Mice deficient for both Stk24 and Stk25, but not for either of them individually, developed aggressive vascular lesions with the characteristics of cavernomas at an early age. Stk25 deficiency also gave rise to vascular anomalies in the context of Stk24 heterozygosity. Human endothelial cells deficient for both kinases phenocopied several of the consequences of CCM3 loss, and single STK25 deficiency also induced KLF2 expression, Golgi dispersion, altered distribution of β-catenin, and appearance of stress fibers.

CONCLUSIONS

The CCM3-associated kinases STK24 and STK25 play a major role in the inhibition of cavernoma development.

Monographic consultation of onconephrology. Rationale and implementation

The increase in demand for medical care for renal complications associated with neoplastic diseases is a reality in most nephrology departments. In response to this overall situation, the creation of healthcare models such as monographic consultations and develop training programs in Onconephrology could improve the care of these patients. Through an exploratory and descriptive study, we identified current situation of kidney involvement in cancer patients. The objective of the present study is to establish the criteria for specific assistance in the field of Onconephrology. For this, we have reviewed key aspects and analyzed the current situation in our country, through a survey addressed to all nephrologists through the Spanish Society of Nephrology., together with the experience of two Spanish centers. From this information, we have established some requirements and recommendations for the start-up of these consultations.

POU1F1 transcription factor induces metabolic reprogramming and breast cancer progression via LDHA regulation

Metabolic reprogramming is considered hallmarks of cancer. Aerobic glycolysis in tumors cells has been well-known for almost a century, but specific factors that regulate lactate generation and the effects of lactate in both cancer cells and stroma are not yet well understood. In the present study using breast cancer cell lines, human primary cultures of breast tumors, and immune deficient murine models, we demonstrate that the POU1F1 transcription factor is functionally and clinically related to both metabolic reprogramming in breast cancer cells and fibroblasts activation. Mechanistically, we demonstrate that POU1F1 transcriptionally regulates the lactate dehydrogenase A (LDHA) gene. LDHA catalyzes pyruvate into lactate instead of leading into the tricarboxylic acid cycle. Lactate increases breast cancer cell proliferation, migration, and invasion. In addition, it activates normal-associated fibroblasts (NAFs) into cancer-associated fibroblasts (CAFs). Conversely, LDHA knockdown in breast cancer cells that overexpress POU1F1 decreases tumor volume and [¹⁸F]FDG uptake in tumor xenografts of mice. Clinically, POU1F1 and LDHA expression correlate with relapse- and metastasis-free survival. Our data indicate that POU1F1 induces a metabolic reprogramming through LDHA regulation in human breast tumor cells, modifying the phenotype of both cancer cells and fibroblasts to promote cancer progression.

Monographic consultation of onconephrology. Rationale and implementation

The increase in demand for medical care for renal complications associated with neoplastic diseases is a reality in most nephrology departments. In response to this overall situation, the creation of healthcare models such as monographic consultations and develop training programs in onconephrology could improve the care of these patients. Through an exploratory and descriptive study, we identified current situation of kidney involvement in cancer patients. The objective of the present study is to establish the criteria for specific assistance in the field of onconephrology. For this, we have reviewed key aspects and analyzed the current situation in our country, through a survey addressed to all nephrologists through the Spanish Society of Nephrology, together with the experience of 2 Spanish centers. From this information, we have established some requirements and recommendations for the start-up of these consultations.

High Levels of Receptor Tyrosine Kinases in CCM3-Deficient Cells Increase Their Susceptibility to Tyrosine Kinase Inhibition

Cerebral cavernous malformations (CCMs) are vascular malformations that can be the result of the deficiency of one of the CCM genes. Their only present treatment is surgical removal, which is not always possible, and an alternative pharmacological strategy to eliminate them is actively sought. We have studied the effect of the lack of one of the CCM genes, CCM3, in endothelial and non-endothelial cells. By comparing protein expression in control and CCM3-silenced cells, we found that the levels of the Epidermal Growth Factor Receptor (EGFR) are higher in CCM3-deficient cells, which adds to the known upregulation of Vascular Endothelial Growth Factor Receptor 2 (VEGFR2) in these cells. Whereas VEGFR2 is upregulated at the mRNA level, EGFR has a prolonged half-life. Inhibition of EGFR family members in CCM3-deficient cells does not revert the known cellular effects of lack of CCM genes, but it induces significantly more apoptosis in CCM3-deficient cells than in control cells. We propose that the susceptibility to tyrosine kinase inhibitors of CCM3-deficient cells can be harnessed to kill the abnormal cells of these lesions and thus treat CCMs pharmacologically.

Management of Hemodialysis Patients with Suspected or Confirmed COVID-19 Infection: Perspective from the Spanish Nephrology

Background

The recent SARS-CoV-2 coronavirus pandemic has signified a significant effect on the health of the population worldwide. Patients on chronic RRT have been affected by the virus, and they are at higher risk due to the frequent comorbid conditions. Here, we show the results of the COVID-19 Registry of the Spanish Society of Nephrology during the first 6 weeks of the outbreak.

Methods

This study is an analysis of the data recorded on a registry of patients with ESKD on RRT who tested positive for COVID-19. The aim was to evaluate clinical conditions, therapeutic management, and consequences, including outcome. The registry began on March 18th, 2020. It includes epidemiologic data, cause of CKD, signs and symptoms of the infection, treatments, and outcomes. Patients were diagnosed with SARS-CoV-2 infection on the basis of the results of PCR of the virus obtained from nasopharyngeal/oropharyngeal swabs. The tests were performed on symptomatic patients and on those who mentioned contact with infected patients.

Results

As of May 2, the registry included data on 1397 patients (in-center hemodialysis [IC-HD], 63%; kidney transplant [Tx], 34%; peritoneal dialysis [PD], 3%; and home hemodialysis, 0.3%). The mean age was 67±15 years, and two-thirds were men. Dialysis vintage was 46±41 months, and the time after transplantation was 59±54 months. Eighty-five percent of the patients required hospital admission, and 8% had to be transferred to intensive care units. Overall mortality was 25% (IC-HD, 27%; Tx, 23%; and PD, 15%), and significant proportions of deceased patients have advanced age, are on IC-HD, and presented pneumonia. Age and pneumonia were independently associated with the risk of death.

Conclusions

SARS-CoV-2 infection affected a significant number of Spanish patients on RRT, mainly those on IC-HD. Hospitalization rates and mortality were high. The factors more closely related to mortality were age and pneumonia.

Colonisation of the male reproductive tract in asymptomatic infertile men: Effects on semen quality

The objective was to explore presence/detection of microorganisms in the male reproductive tract (PMMRT) in asymptomatic patients undergoing infertility treatment and their effects on semen quality in our region. This study enrolled 205 men (mean age, 35.9 years) in a single-centre, tertiary university hospital from December 2015 to December 2016. We used the modified Meares-Stamey test, real-time polymerase chain reaction (rt-PCR) and the National Institutes of Health Chronic Prostatitis Sympton Index (NHI-CPSI) questionnaire to address this issue. No patient met the prostatitis criteria by the modified Meares-Stamey 4-sample test, 33 (16.1%) were positive for rt-PCR in the first-voided urine for any of the Mycoplasma (Ureaplasma urealyticum/parvum, Mycoplasma hominis/genitalium) and C. trachomatis was detected in two cases (1%), and three for rt-PCR in semen for HPV high-risk genotypes non-16/18 (1.5%). Significant statistical differences were reported among patients with and without PMMRT in terms of lower rate of progressive spermatozoa (PR) (p < .034), total motile sperm count (p < .028), normal morphologic forms, especially in the sperm head (p < .001) and highest viscosity (p < .012). It was concluded that PMMRT, specially Mycoplasmas, in asymptomatic infertility men, affects semen quality. The NIH-CPSI questionnaire was not a valid initial screening to subsequently evaluate the presence of prostatitis/PMMRT.

Prevalence of genital Mycoplasma and response to eradication treatment in patients undergoing assisted reproductive techniques

OBJECTIVE

Several studies have reported greater success of fertilisation by ART in couples who were not infected by Ureaplasma. Increased semen quality and better results have also been observed in couples who were treated with antibiotics to eradicate the infection. The aim of this study was to determine the prevalence of genital mycoplasmas in urine samples from male partners enrolled in the Assisted Reproduction Program (ARP) in our healthcare area so that, positive cases can be treated prior to the use of ART in order to increase the quality of semen, improve the embryo implantation rates and minimize the risk of adverse effects during pregnancy.

METHODS

This study included couples enrolled in the ARP during 2016. Mycoplasma detection was made using real-time PCR. In positive cases, both members of the couple were treated with antibiotics until eradication of the microorganism. The antibiotics used were: azithromycin, doxycycline, levofloxacin, moxifloxacin, and clindamycin.

RESULTS

Of the 205 men studied, 33 were positive: Ureaplasma urealyticum 15.1%, Mycoplasma hominis 3.9%. Eradication treatment with azithromycin failed in 50% compared to 10.2% for doxycycline. Of the 5 cases treated with levofloxacin, only 2 achieved elimination of U. urealyticum.

CONCLUSIONS

We consider that genital mycoplasma routine screening could be useful in order to increase the quality of semen which could simplify the in vitro fertilisation procedures and raise the success rate of embryo implantation and pregnancy, especially when fast, sensitive and specific technics as real time PCR are used.

Onco-Nephrology: Cancer, chemotherapy and kidney

Chronic kidney disease (CKD), cancer and haematological diseases share areas of reciprocal influence. Cancer can affect the kidney either as glomerular lesions or as a result of the toxic effects of medication or radiation with acute (thrombotic microangiopathy, acute kidney injury, interstitial nephropathies among others) or chronic processes (worsening of CKD after nephrectomy due to renal cancer, interstitial fibrosis, hydroelectrolytic disorders). On the other hand, patients who require renal replacement therapy with dialysis and particularly with kidney transplantation are at high risk of onset of cancer due to the immunosuppression situation that they generate. In addition to conventional chemotherapy, innovative treatments have been developed: target agents against growth factors and their receptor; anti-angiogenic drugs; immunoregulatory proteins; cell cycle regulators; and enzyme inhibitors. Other immunotherapeutic approaches have also been developed, such as vaccines, adoptive cell therapy (CAR T cells) or development of antibodies. All these therapeutic advances will improve the outcomes against cancer and haematological diseases, but they are not free from secondary renal problems. Onco-Nephrology is already an important area for the Spanish Society of Nephrology with a large number of inter-consultations. Nephrologists need a better understanding of rapidly evolving areas of cancer biology and its treatment in order to become valued members of the cancer care team and to provide the best nephrology care possible.

Eculizumab in secondary atypical haemolytic uraemic syndrome

Background. Complement dysregulation occurs in thrombotic microangiopathies (TMAs) other than primary atypical haemolytic uraemic syndrome (aHUS). A few of these patients have been reported previously to be successfully treated with eculizumab.

Methods. We identified 29 patients with so-called secondary aHUS who had received eculizumab at 11 Spanish nephrology centres. Primary outcome was TMA resolution, defined by a normalization of platelet count (>150 × 10⁹/L) and haemoglobin, disappearance of all the markers of microangiopathic haemolytic anaemia (MAHA), and improvement of renal function, with a ≥25% reduction of serum creatinine from the onset of eculizumab administration.

Results. Twenty-nine patients with secondary aHUS (15 drug-induced, 8 associated with systemic diseases, 2 with postpartum, 2 with cancer-related, 1 associated with acute humoral rejection and 1 with intestinal lymphangiectasia) were included in this study. The reason to initiate eculizumab treatment was worsening of renal function and persistence of TMA despite treatment of the TMA cause and plasmapheresis. All patients showed severe MAHA and renal function impairment (14 requiring dialysis) prior to eculizumab treatment and 11 presented severe extrarenal manifestations. A rapid resolution of the TMA was observed in 20 patients (68%), 15 of them showing a ≥50% serum creatinine reduction at the last follow-up. Comprehensive genetic and molecular studies in 22 patients identified complement pathogenic variants in only 2 patients. With these two exceptions, eculizumab was discontinued, after a median of 8 weeks of treatment, without the occurrence of aHUS relapses.

Conclusion. Short treatment with eculizumab can result in a rapid improvement of patients with secondary aHUS in whom TMA has persisted and renal function worsened despite treatment of the TMA-inducing condition.

An update for atypical haemolytic uraemic syndrome: diagnosis and treatment. A consensus document

Haemolytic uraemic syndrome (HUS) is a clinical entity defined as the triad of nonimmune haemolytic anaemia, thrombocytopenia, and acute renal failure, in which the underlying lesions are mediated by systemic thrombotic microangiopathy (TMA). Different causes can induce the TMA process that characterizes HUS. In this document we consider atypical HUS (aHUS) a sub-type of HUS in which the TMA phenomena are the consequence of the endotelial damage in the microvasculature of the kidneys and other organs due to a disregulation of the activity of the complement system. In recent years, a variety of aHUs-related mutations have been identified in genes of the the complement system, which can explain approximately 60% of the aHUS cases, and a number of mutations and polymorphisms have been functionally characterized. These findings have stablished that aHUS is a consequence of the insufficient regulation of the activiation of the complement on cell surfaces, leading to endotelial damage mediated by C5 and the complement terminal pathway. Eculizumab is a monoclonal antibody that inhibits the activation of C5 and blocks the generation of the pro-inflammatory molecule C5a and the formation of the cell membrane attack complex. In prospective studies in patients with aHUS, the use of Eculizumab has shown a fast and sustained interruption of the TMA process and it has been associated with significative long-term improvements in renal function, the interruption of plasma therapy and important reductions in the need of dialysis. According to the existing literature and the accumulated clinical experience, the Spanish aHUS Group published a consensus document with recommendations for the treatment of aHUs (Nefrologia 2013;33[1]:27-45). In the current online version of this document, we update the aetiological classification of TMAs, the pathophysiology of aHUS, its differential diagnosis and its therapeutic management.

Effect of pentoxifylline on renal function and urinary albumin excretion in patients with diabetic kidney disease: the PREDIAN trial

Diabetic kidney disease (DKD) is the leading cause of ESRD. We conducted an open-label, prospective, randomized trial to determine whether pentoxifylline (PTF), which reduces albuminuria, in addition to renin-angiotensin system (RAS) blockade, can slow progression of renal disease in patients with type 2 diabetes and stages 3-4 CKD. Participants were assigned to receive PTF (1200 mg/d) (n=82) or to a control group (n=87) for 2 years. All patients received similar doses of RAS inhibitors. At study end, eGFR had decreased by a mean±SEM of 2.1±0.4 ml/min per 1.73 m(2) in the PTF group compared with 6.5±0.4 ml/min per 1.73 m(2) in the control group, with a between-group difference of 4.3 ml/min per 1.73 m(2) (95% confidence interval [95% CI], 3.1 to 5.5 ml/min per 1.73 m(2); P<0.001) in favor of PTF. The proportion of patients with a rate of eGFR decline greater than the median rate of decline (0.16 ml/min per 1.73 m(2) per month) was lower in the PTF group than in the control group (33.3% versus 68.2%; P<0.001). Percentage change in urinary albumin excretion was 5.7% (95% CI, -0.3% to 11.1%) in the control group and -14.9% (95% CI, -20.4% to -9.4%) in the PTF group (P=0.001). Urine TNF-α decreased from a median 16 ng/g (interquartile range, 11-20.1 ng/g) to 14.3 ng/g (interquartile range, 9.2-18.4 ng/g) in the PTF group (P<0.01), with no changes in the control group. In this population, addition of PTF to RAS inhibitors resulted in a smaller decrease in eGFR and a greater reduction of residual albuminuria.

Low-sample flow secondary electrospray ionization: improving vapor ionization efficiency

In secondary electrospray ionization (SESI) systems, gaseous analytes exposed to an elecrospray plume become ionized after charge is transferred from the charging electrosprayed particles to the sample species. Current SESI systems have shown a certain potential. However, their ionization efficiency is limited by space charge repulsion and by the high sample flows required to prevent vapor dilution. As a result, they have a poor conversion ratio of vapor into ions. We have developed and tested a new SESI configuration, termed low-flow SESI, that permits the reduction of the required sample flows. Although the ion to vapor concentration ratio is limited, the ionic flow to sample vapor flow ratio theoretically is not. The new ionizer is coupled to a planar differential mobility analyzer (DMA) and requires only 0.2 lpm of vapor sample flow to produce 3.5 lpm of ionic flow. The achieved ionization efficiency is 1/700 (one ion for every 700 molecules) for TNT and, thus, compared with previous SESI ionizers coupled with atmospheric pressure ionization-mass spectrometry (API-MS) (Mesonero, E.; Sillero, J. A.; Hernández, M.; Fernandez de la Mora, J. Philadelphia PA, 2009) has been improved by a large factor of at least 50-100 (our measurements indicate 70). The new ionizer coupled with the planar DMA and a triple quadrupole mass spectrometer (ABSciex API5000) requires only 20 fg (50 million molecules) to produce a discernible signal after mobility and MS(2) analysis.

Transversal Modulation Ion Mobility Spectrometry (TM-IMS), a new mobility filter overcoming turbulence related limitations

The analysis of ions according to their mobility is a technique that is attracting increasing interest. The new technology presented here, which we have termed Transversal Modulation Ion Mobility Spectrometry (TM-IMS), utilizes only electric fields, operates at atmospheric pressure, produces a continuous output of mobility selected ions (according to their true mobility and not to nonlinear effects), and has a very accessible inlet and outlet. These features would make it an ideal choice for tandem IMS-MS analysis in combination with most commercial Atmospheric Pressure Interface MS (API-MS) systems. We modeled and evaluated two different TM-IMS configurations (TM-IMS, and multistage TM-IMS), and we concluded that the most promising configuration would be a two-stage TM-IMS. We developed and tested a TM-IMS, and the measured resolving power is R = 55. The TM-IMS behaves similarly to the planar Differential Mobility Analyzer, but the TM-IMS utilizes only electric fields, and no fragile flow with high Reynolds numbers is required. We tested the robustness of the TM-IMS, which proves to be a very robust and reliable analyzer: the required voltage accuracy is 5 V in 10 kV, and the mechanical precision is 1 mm in 5 cm.

Should we adjust erythropoiesis-stimulating agent dosage to postdialysis hemoglobin levels? A pilot study

Background

Predialysis hemoglobin (Hb) may overestimate the true erithropoiesis-stimulating agents (ESA) requeriments. We tested whether predialysis Hb is a reliable predictor of the postdialysis level to better control ESA dosage, and evaluated the relation between ESA, Hb and cardiovascular events (CVE).

Methods

Cohort study including 67 stable hemodialysis patients. Pre- and post-dialysis Hb concentrations were measured, and ESA doses were calculated. A model to predict post-dialysis Hb is proposed. During 18 months follow-up, CVE, hospitalizations and mortality were collected.

Results

After dialysis, Hb cocentration rise by 6.1 ± 5.6%. Using postdialysis Hb, the weight-adjusted ESA dosage would be lower respect to the prescription using predialysis Hb: 104 ± 120 vs 128 ± 124 U/kg/week (P < 0.001). Using predialysis Hb, 40.2% of subjects had a Hb level above 12 g/dL, whereas this percent increased to 70.1% using postdialysis Hb. During the follow-up, 15 patients had a CVE, without differences in Hb levels respect to subjects without CVE. However, patients with CVE had received higher ESA doses: 186 ± 180 vs 111 ± 98 U/Kg/week (P = 0.001). The prediction model is: Postdialysis Hb (g/dL) = 1.636 + 0.871 x predialysis Hb* (g/dL) + 0.099 x UF rate** (mL/kg/h) - 0.39 for women***. [R² = 0.74; *P < 0,001; **P = 0.001; ***P = 0.03).

Conclusions

Postdialysis Hb can be a better reflect of the real Hb level in hemodialysis patients. Using postdialysis Hb would avoid the use of inappropriately high ESA doses. The prediction of postdialysis Hb with an adjusted model would help us to identify those patients at risk for ESA overdosification.

[Current peritoneal dialysis compared with haemodialysis: medium-term survival analysis of incident dialysis patients in the Canary Islands in recent years]

INTRODUCTION

Important differences in patient survival exist between peritoneal dialysis (PD) and haemodialysis (HD). Several different studies have shown that PD yields a better survival rate than HD in the first and second years of treatment, especially in younger patients and non-diabetic patients with low comorbidity, whereas HD produces better results in diabetic patients, elderly patients, and in patients with greater comorbidity. In recent years, interesting changes have occurred in PD units in the Canary Islands, such as the introduction of peritoneal dialysis solutions with bicarbonate dialysate and low content of glucose degradation products, extended use of automated dialysis, and continuity of physicians and nurses in PD units, in addition to enhancing visits for advanced chronic kidney disease (ACKD).

OBJECTIVE

This situation led us to perform our study with the primary objective of comparing medium-term survival among incident dialysis patients on HD versus PD in recent years in the Canary Islands, and as a secondary objective, to compare survival between these two types of dialysis by subgroups as defined by age, sex and diabetes.

MATERIAL AND METHODS

This was a retrospective cohort study comparing survival between HD and PD patients starting dialysis in the Canary Islands between 01/01/2006 and 31/12/2009, with adjustment based on the propensity score analysis. We analysed data from the RERCAN database, which collects data on demographic variables, changes in type of dialysis, province and hospital of the patient, and mortality and its causes. We calculated Kaplan-Meier estimates of survival based on the overall population and stratified by age, sex and diabetes. We applied a Cox proportional hazards model for survival to estimate the relative mortality risk of PD compared with HD, using as independent variables: age, sex, quartiles of propensity score, the province of the patient, and diabetes. Finally, we applied a Cox model with time-dependent effects, using as a fixed risk factor the initial type of dialysis in order to assess the effect of PD versus HD on short and medium-term survival.

RESULTS

The cohort included 1469 patients (173 PD and 1296 HD), with a mean age of 62.5 years, 65% male. Mean follow-up was 16.2±12.4 months. Factors associated with greater probability of choosing PD were younger age and living in the province of Las Palmas. The cumulative mortality in the intention to treat (ITT) analysis was 27.1% in the HD group and 8.7% in the PD group, P<.0001. The cumulative probability of survival by ITT using PD vs HD was 96.6% versus 89% at 6 months (P<.001), 96% versus 80% at 12 months (P<.001), 90% versus 65% at 24 months (P<.001), 82% versus 58% at 36 months (P<.001) and 73% versus 45% at 46 months (P<.001). In the subgroup analysis, survival was also higher in PD patients compared to HD patients both over and under 65 years old, in both diabetic and non-diabetic patients, and in both genders. The same analysis from the 90th day onward produced similar results. In the ITT analysis, the Cox-adjusted mortality risk for PD was 61% lower than for HD (RR: 0.398, 95% CI 0.237-0.669, P=.001), adjusted for age, diabetes, sex, patient's province and propensity score. Broken down by years of survival on the technique used, the relative risk of death for PD compared with HD in the first year was also significantly lower (RR 0.509, 95% CI: 0.259-0.999, P=.049). From year 2 onwards, only age was a risk factor for mortality (RR: 2.785, 95% CI: 1.525-5.086, P=.001) and no differences were shown between the two dialysis techniques.

CONCLUSION

In the Canary Islands, PD has demonstrated survival advantages over HD in the short and medium term. It is remarkable that this benefit was found in young and old patients, men and women, and diabetic and non-diabetic patients, and that this advantage was maintained even after years of being on dialysis.

[Heparin-induced thrombocytopenia in hemodialysis. Case report and review of the literature]

Thrombocytopenia is a potential complication of heparin therapy. There are two forms of heparin-induced thrombocytopenia (HIT). Type-I HIT is characterized by a mild decrease in platelet count that occurs within the first 2-4 days after heparin initiation. The platelet count often returns to normal without stop heparin treatment. The mechanism of thrombocytopenia appears to be due to a direct effect of heparin on platelet activation. The second form (type-II) is an immune-mediated disorder characterized by severe thrombocytopenia, which may include both arterial and venous thrombosis. We present a case of type-II HIT occurred in a hemodialysis patient resulting in acute pulmonary embolism and peripheral venous thrombosis, and review the literature.

Low prevalence of vancomycin-resistant enterococci in clinical samples from hospitalized patients of the Canary Islands, Spain

Over the last decade vancomycin-resistant enterococci (VRE) have emerged as nosocomial pathogens. The aim of this study was to determine the prevalence of VRE in clinical samples from hospitalized patients in the Canary Islands. From April to November 2000, 437 enterococci were isolated from patients hospitalized at the four main health care centers in those islands. Identification to the species level was performed with the GPS-TA (Vitek 1) or the Wider I system. A PCR assay was used to determine the genotype of glycopeptide resistance ( vanA, vanB, vanC1, and vanC2/C3 genes). Only three (0.7%) VRE were detected: one vanA Enterococcus faecalis, and two vanC1 Enterococcus gallinarum. To our knowledge, this is the first VRE study carried out in the Canary Islands hospitals, and the results showed a low prevalence of VRE.

Randomized prospective comparison between erythropoietin and androgens in CAPD patients

BACKGROUND

Anemia and malnutrition are significant complications in peritoneal dialysis (PD) patients. Previous studies in hemodialysis have shown that androgens are effective as therapy for anemia; however, this has not been tested in a randomized prospective trial in PD patients. Furthermore, the anabolic properties of androgens may exert additional benefits on the nutritional status in this population.

METHODS

Twenty-seven stable male patients over 50 years who were under maintenance continuous ambulatory peritoneal dialysis (CAPD) therapy were randomized to receive recombinant human erythropoietin (rHuEPO; N = 14) or nandrolone decanoate (ND; 200 mg/week IM; N = 13) as therapy for anemia. The evolution of hematologic parameters and the impact on both nutritional anthropometric and biochemical variables were evaluated after six months of treatment.

RESULTS

Hemoglobin and hematocrit experienced similar increases in both groups: from 8.5 +/- 0.9 g/dL and 25.8 +/- 2.7% to 11.7 +/- 0.6 g/dL and 34.7 +/- 1.6% (P < 0.001) in patients receiving rHuEPO, and from 8.9 +/- 0.8 and 27 +/- 2.2% to 11.8 +/- 0.4 g/dL and 35.1 +/- 1.5% (P < 0.001) in subjects treated with ND. At the end of the study, out of the diverse nutritional variables included in this investigation, only weight and body mass index significantly increased in the rHuEPO group. Conversely, both anthropometric [weight, body mass index, triceps skinfold, mid-arm circumference (MAC) and mid-arm muscle circumference (MAMC)] and biochemical parameters (serum total proteins, albumin, prealbumin and transferrin) were significantly increased in patients treated with ND. In this group, serum urea nitrogen, urea net excretion and protein equivalent of nitrogen appearance significantly decreased. These facts, together with an increase in serum creatinine and no changes in dietary intake during the study, suggest a rise in muscle mass related to an anabolic effect of nandrolone decanoate. Interestingly, serum levels of insulin-like growth factor type 1 (IGF-1) increased in patients on the androgen group compared to subjects treated with rHuEPO. Moreover, there was a positive and significant correlation between the rise in IGF-1 concentrations and the increase in hemoglobin, hematocrit, MAC and MAMC.

CONCLUSIONS

Androgens therapy improved the anemia in elderly male CAPD patients in a similar manner to that observed with rHuEPO. Furthermore, compared with rHuEPO, androgen administration was associated with beneficial effects on nutritional status. The mechanism of action of androgens on hematologic and nutritional parameters might be mediated, at least in part, by IGF-1.

[Efficiency of dialysis with albumin in the treatment of patients with advanced hepatic insufficiency: initial experience with the MARS system in Spain]

During liver failure there is an accumulation of toxic substances secondary to the loss of liver function. In order to eliminate these substances various extracorporeal depuration therapies have been employed. Recently, we have used a new treatment, MARS (Molecular Adsorbent Recirculating System), in 3 patients diagnosed with severe liver failure. This system consists of an albumin rich (20%) dialysate circuit, with two areas of depuration. In one area, the albumin dialysate is in contact with blood through a high-flux albumin coated membrane, where albumin bound substances are eliminated. In the other area, the albumin dialysate is in contact with a standard bicarbonate dialysate through a low-flux membrane, which permits the elimination of water soluble substances. The albumin of the circuit is continuously regenerated through charcoal and ion exchanger filters. In order to determine those liver failure patients suitable to receive MARS therapy we established several inclusion criteria. All patients underwent a complete clinical and biochemical evaluation before and after each treatment. All of them showed an improvement of their clinical (attenuation of pruritus and encephalopathy) and biochemical (decrease of bilirubin levels) parameters. During the period of treatment 2 patients developed an increase in plasma creatinine levels together with a decrease of urinary volume. There were no hemodynamic or technical complications during the treatment. These promising results deserve further controlled studies large enough to permit confirmation.

Long-term effect of bilateral ovariectomy on endothelial function in aortic rings of spontaneously hypertensive rats: role of nitric oxide

Endothelial dysfunction associated with both menopause and hypertension could be one of the possible explanations for increased cardiovascular morbidity and mortality in hypertensive postmenopausal women. The aim of the present study was to investigate the long-term effect of menopause (bilateral ovariectomy) on endothelial function in isolated aortic rings of spontaneously hypertensive rats (SHR). Aortic rings were suspended in organ chambers filled with physiological salt solution (95% O2, 5% CO2, 37 degrees C), and isometric tension was measured. In studies designed to assess the tone-related release of nitric oxide (NO) from phenylephrine-precontracted aortic rings, we found that vasoconstriction induced by L-NAME was greater in aortic rings from sham-ovariectomized SHR (SHAM SHR) than in those obtained from ovariectomized SHR (OVX SHR). Concentration-related relaxant responses to superoxide dismutase were significantly greater in the SHAM SHR than in the OVX SHR. In contrast, receptor-mediated release of NO was not altered by ovariectomy, as deduced from acetylcholine (ACh) concentration-responses curves. Responses to the exogenous NO donor sodium nitroprusside (SNP) were also identical in both ovariectomized and sham-ovariectomized groups, ruling out differences in smooth muscle reactivity to NO. These results show that NO release is impaired in OVX SHR, an animal model of simultaneous hypertension and menopause.

Androgens for the treatment of anemia in peritoneal dialysis patients

Before the advent of recombinant human erythropoietin (EPO), androgens were used for treatment of anemia in dialysis patients. However, after the availability of recombinant EPO in the 1980s, the use of these substances was abondoned. We have previously reported that androgens have beneficial actions on anemia in selected hemodialysis patients. In the present study we have analyzed the effects of androgen administration on hematologic parameters in peritoneal dialysis patients. We evaluated 9 patients treated for 6 months with nandrolone decanoate (200 mg/week intramuscularly). Hemoglobin and hematocrit values experienced a significant increment with respect to basal values during the study (9.2 +/- 0.7 g/dL and 27.7% +/- 2.3% at basal vs. 11.9 +/- 0.5 g/dL and 35.3% +/- 1.6% at month 6, respectively; P < 0.001). In addition to the effects on the hematologic parameters, androgen administration also had beneficial anabolic actions with a significant increment in the serum concentration of total proteins and albumin (basal, 6.1 +/- 0.3 g/dL and 3.1 +/- 0.4 g/dL vs. 6.7 +/- 0.4 g/dL and 3.8 +/- 0.4 g/dL at month 6, respectively, P < 0.01). The only adverse effect was a rise in the serum concentration of triglycerides (176 +/- 54 mg/dL vs. 144 +/- 53 mg/dL, P < 0.01). In conclusion, androgen administration has beneficial effects on erythropoiesis as well as positive anabolic actions in patients under peritoneal dialysis.

Age-related loss of proliferative activity of human vascular smooth muscle cells in culture

This work studied the proliferation activity in cultures of vascular smooth muscle cells (SMC) from individuals of different ages. The cells derived from arteries of 12 donors of both sexes from 45 to 91 years of age. The main parameter considered was the 'proliferation rate' (cells grown per day in the different culture passages) taking into account the age of the donor. No significant relationship between age of the donor and the cell life in proliferation was found. On the contrary, the mean time of passage duration for reaching the maximum of proliferation as well as its 'efficiency' (maximum of proliferation rate registered/mean time of passage duration) show a statistically significant dependence on the age of the donor. Furthermore, the proliferation rate measured in each passage is statistically significant related to donor age. The regressions obtained show a similar negative slope (VC 4%). Considering the first five culture passages, the regression crosses the x-axis at the age of 105.6+/-11.7 years. This age in which no proliferative activity of human SMC would be expected lies near the limit of maximum life potential for human beings. Our results suggest that with advancing donor age there is an increasing number of senescent SMC either primarily transferred or appeared in the culture. Vascular SMC of individuals whose life is near the end would almost be all senescent and therefore show extremely low proliferation rates in the culture. If the proliferative activity of arterial SMC is a condition for atherogenesis, the proportion of senescent cells would be inversely related to the propensity of developing the atheroma because of the inability of these cells to divide.

Relationship between serum magnesium and parathyroid hormone levels in hemodialysis patients

Acute magnesium (Mg) infusion decreases patathyroid hormone (PTH) secretion. However, the effect of chronic hypermagnesemia on PTH levels in dialysis patients is not well established. We studied 110 hemodialysis patients (mean age, 55 +/- 14 years; time on dialysis, 35 +/- 28 months) not receiving vitamin D and undergoing dialysis with an Mg dialysate concentration of 1.2 mg/dL. The primary phosphate binder was calcium carbonate, and 43% of the patients also needed aluminum hydroxide. During a 6-month period, calcium (Ca), phosphorus (P), and total serum Mg were measured every 2 months; intact PTH and aluminum (Al) were measured every 6 months. The mean value of each parameter was computed. Hypermagnesemia (serum Mg > 2.47 mg/dL) was observed in 73% of the patients. Mg and Ca were inversely correlated with PTH levels (r = -0.48; P < 0.001 and r = -0.21; P < 0.05, respectively). After adjusting for Ca and P (partial correlation analysis), Mg and PTH were inversely correlated (r = -0.58; P < 0.001). A stepwise multiple regression analysis showed that PTH levels were predicted by Mg (P < 0.001), alkaline phosphatase (P < 0.01), and P levels (P< 0.05; multiple R = 0.57; P < 0.001), whereas Ca level, sex (dummy variable), diabetes (dummy variable), time on dialysis, and Al level were not predictive. Patients with inadequately low PTH levels (relative hypoparathyroidism, PTH < 120 pg/mL; n = 52) showed greater serum Mg concentrations than the rest (n = 58; 3.01 +/- 0.33 v 2.63 +/- 0.38 mg/dL; P < 0.001). In conclusion, serum Mg concentrations in dialysis patients are independently associated with PTH levels, suggesting that chronic hypermagnesemia may decrease PTH secretion and/or synthesis. In addition, chronic hypermagnesemia of dialysis patients may have a role in the pathogenesis of adynamic bone disease.

Effects of pentoxifylline on the haematologic status in anaemic patients with advanced renal failure

OBJECTIVE

Erythropoietin (EPO) deficiency is the main cause of renal anaemia. However, inhibition of erythropoiesis by cytokines such as tumour necrosis factor alpha (TNF-a) may play an important role. The aim of this work was to study the effects of pentoxifylline, an agent with anti-TNF-a properties, on the haematologic status in anaemic patients with advanced renal failure.

MATERIAL AND METHODS

In a prospective study, 7 anaemic patients with advanced renal disease (creatinine clearance <30 ml/min) were treated with pentoxifylline (400 mg orally daily) for 6 months. The evolution of haemoglobin, haematocrit, creatinine clearance and serum EPO and TNF-a a concentrations were compared with those obtained from an untreated control group.

RESULTS

Haemoglobin and haematocrit significantly increased in the pentoxifylline-treated patients (9.9+/-0.5 g/dl and 27.9+/-1.6% at baseline; 10.6+/-0.6 g/dl and 31.3+/-1.9% at the 6th month, respectively, p < 0.01), whereas no variation was seen in the control group. Serum EPO levels remained stable in all patients. However, the serum TNF-a concentration decreased significantly in patients receiving pentoxifylline (basal 623+/-366 pg/ml; 6th month 562+/-358 pg/ml, p < 0.01), but not in the control group.

CONCLUSIONS

Our findings suggest that the inhibition of erythropoiesis by cytokines may play a significant role in renal anaemia. The administration of agents with anti-cytokine properties, such as pentoxifylline, can improve the haematologic status in anaemic patients with advanced renal failure.

Urinary protein excretion and serum tumor necrosis factor in diabetic patients with advanced renal failure: effects of pentoxifylline administration

In 24 diabetic patients with advanced renal failure (creatinine clearance [C(Cr)] < 35 mL/min), we prospectively studied serum tumor necrosis factor-alpha (TNF-alpha) levels, the possible relationship with urinary protein excretion, and the effects of pentoxifylline (PTF) administration. PTF (400 mg daily) was administered for 6 months to 14 patients, and the results were compared with data from a control group (n = 10). Baseline parameters were similar in both groups. At the end of the study, urinary protein excretion and serum TNF-alpha decreased in the active group from 2.7 (1.2 to 5.8) g/d and 569 +/- 285 pg/mL to 1.1 (0.3 to 4.0) g/d and 329 +/- 232 pg/mL, respectively (P < 0.001). By contrast, proteinuria and TNF-alpha did not change in the control group. Regression analysis showed a significant correlation between proteinuria and serum TNF-alpha both at basal (r = 0.55) and at the sixth month (r = 0.57). Furthermore, the reduction of urinary protein excretion was strongly correlated with the decrease of TNF-alpha (r = 0.72, P < 0.01). Serum Cr and C(Cr) remained stable in both groups during the study. Our findings suggest that cytokines might play a role in renal damage in diabetic nephropathy. PTF is effective in reducing proteinuria in diabetic patients with advanced renal failure. The anticytokine activity of PTF may be a further explanation for this antiproteinuric effect.

Autosomal dominant polycystic kidney disease associated with familial sensorineural deafness

Autosomal dominant polycystic kidney disease (ADPKD) is characterized by both renal and non-renal disorders. Extrarenal involvement includes noncystic manifestations such as cardiovascular abnormalities, colonic diverticula and intracranial aneurysms. Familial sensorineural hearing loss (SNHL) has been included in the definition of Alport's syndrome. However, other types of nephropathy have been occasionally associated with hereditary deafness. The association of ADPKD with hereditary SNHL has not been previously documented. We report a family with ADPKD associated with bilateral sensorineural deafness in a pedigree of four affected members in four generations.

Effects of losartan on the treatment of posttransplant erythrocytosis

Erythrocytosis is a relatively common complication of renal transplantation. Recent observations indicate that angiotensin-converting enzyme inhibitors correct renal transplant erythrocytosis. Other drugs to inhibit the renin-angiotensin system have been developed recently. The newest of these is losartan, a specific antagonist of the angiotensin II type I receptor. We report three patients in which the use of losartan controlled posttransplant erythrocytosis. Our findings suggest that losartan can be effective and safe in the treatment of posttransplant erythrocytosis.

Prediction of left ventricular mass changes after renal transplantation by polymorphism of the angiotensin-converting-enzyme gene

Cardiac complications are the main cause of death in renal transplant patients and left ventricular hypertrophy (LVH) may play a determinant role. An association between the insertion-deletion polymorphism of the angiotensin-converting enzyme (ACE) gene and LVH has been reported in adults. However, little is known about the genetic influence on left ventricular mass changes after renal transplantation, where unique environmental factors, such as cyclosporine A (CsA) and prednisone treatment concur. In fact, CsA treatment has recently been associated with the development of LVH. We prospectively determined the changes on cardiac structure and function, assessed by echocardiographic criteria, in 38 consecutive nondiabetic adults who received a cadaveric renal allograft. They were treated with cyclosporine and prednisone and maintained a good renal function during the follow-up. Echocardiographic studies (M-mode, 2-B and color flow Doppler) were performed without previous knowledge of the genetic typing, at the time of transplantation, and 6 and 12 months later. ACE alleles were typed using a PCR-based assay developed to ascertain the presence of an insertion (I)-deletion (D) polymorphism in intron 16 of the ACE gene. Patients with the so-called "unfavorable" DD genotype (N = 16) were compared with the ID or II genotypes (N = 22). The baseline left ventricular mass index was similar in patients with or without the unfavorable DD genotype (X +/- SE; 166.6 +/- 10.4 vs. 181.3 +/- 9 g/m2, respectively) and a similar proportion fulfilled the criteria of LVH (88% vs. 82%, respectively). The mean percent increase of the left ventricular mass index 12 months after renal transplantation was significantly higher in patients with the DD genotype compared to those with other genotypes (21.3 +/- 7.9 vs. -0.08 +/- 4.9%, respectively; P < 0.05). As a result, 94% of DD patients showed LVH at the end of the follow-up, while 68% of the ID or II patients had LVH (P < 0.05). In addition, the left ventricular ejection fraction significantly increased only in ID or II patients 12 months after transplantation with respect to baseline (ID/II patients, 70.4 +/- 1.5 vs. 63.7 +/- 1.8%; P < 0.05; DD patients, 68.3 +/- 2.1 vs. 63.3 +/- 2.9%). The deleterious effect of the DD genotype was independent of blood pressure, biochemical parameters, weight gain, and cumulative steroids dosages or cyclosporine levels. In conclusion, genetic factors determine the changes on cardiac structure and function after renal transplantation. The presence of the DD genotype of the ACE gene is a marker associated with an elevated risk of LVH in this population.

Progesterone challenge test for the assessment of endometrial pathology in asymptomatic menopausal women

The progesterone challenge test was correlated with endometrial pathology in 130 asymptomatic menopausal women without hormonal treatment. The sensitivity of the test for detection of endometrial proliferative activity was 76%, specificity 100%, positive predictive value 100% and negative predictive value 94.1%. A 10-day test provided better results than a 5-day test. The test seems useful for detection of those at high risk for endometrial cancer.