Cancer among patients on renal replacement therapy: a population-based survey in Lombardy, Italy

When ESKD complicates cancer screening and cancer treatment

End-stage kidney disease (ESKD) affects the recommended screening, incidence, treatment, and mortality of cancer. Cancer occurring in a patient with ESKD can influence candidacy for kidney transplantation as well as dialysis decision-making and cancer treatment. Certain cancers are more common among ESKD patients, notably, viral-mediated cancers that are associated with human papilloma or hepatitis viruses, and urothelial cancers associated with analgesic and Balkan nephropathies. Solid tumors are not believed to occur more frequently in ESKD patients. The presence of ESKD may confer a higher risk of post-surgical complications as well as mortality. The cost-effectiveness of cancer screening depends upon individual cancer risk and estimated overall survival. The high mortality associated with ESKD argues against routine cancer screening in dialysis patients. Cancer treatment in ESKD may be complicated by the need to avoid, adjust doses of and/or coordinate the timing of administration of imaging contrast, chemotherapy, and immunotherapy with dialysis treatments. There is a general dearth of information on the treatment of cancer in ESKD patients. These issues will be discussed, and some general guidelines presented based upon the current literature.

Association between urologic malignancies and end-stage renal disease: A meta-analysis

AIM

Previous studies have suggested a higher incidence of urologic malignancies in end-stage renal disease (ESRD) patients. However, incidence trends of urologic malignancies in ESRD patients remain unclear. The aims of the present study were: (i) to investigate the pooled incidence/incidence trends; and (ii) to assess the risk of urologic malignancies in ESRD patients.

METHODS

A literature search was conducted using MEDLINE, EMBASE and Cochrane Database from inception through April 2017. Studies that reported incidence or odds ratios of urologic malignancies among ESRD patients were included. Pooled odds ratios (OR) and 95%CI were calculated using a random-effect model. The protocol for this meta-analysis is registered with PROSPERO (International Prospective Register of Systematic Reviews; no. CRD42017067687).

RESULTS

Nineteen observational studies with 1 931 073 ESRD patients were enrolled. The pooled estimated incidence of kidney cancer and urothelial cancers (carcinomas of the bladder, ureters, and renal pelvis) in ESRD patients were 0.3% (95%CI: 0.2-0.5%) and 0.5% (95%CI: 0.3-0.8%), respectively. Meta-regression showed significant positive correlation between incidence of urologic malignancies in ESRD patients and year of study (slopes = +0.05 and +0.07, P < 0.001 for kidney cancer and urothelial cancers, respectively). Compared to non-ESRD status, ESRD was significantly associated with both kidney cancer (pooled OR 6.04; 95% CI 4.70-7.77) and urothelial cancers (pooled OR 4.37; 95% CI 2.40-7.96).

CONCLUSION

Our study demonstrates a significant association between ESRD and urologic malignancies. The overall estimated incidence rates of kidney cancer and urothelial cancers are 0.4% and 0.5%, respectively. There is a significant positive correlation between the incidence of urologic malignancies and year of study.

Assessment of Kidney Function in Patients With Cancer

Cancer patients are living longer. The sequelae of cancer treatment and the role of comorbid conditions present before the diagnosis, such as CKD, have been increasingly recognized. The interface between CKD and cancer is multifaceted. CKD is frequently observed in patients with cancer, and cancer treatment contributes to CKD development and progression. In addition, CKD has been recognized as an important risk factor for cancer development and reduced specific cancer survival. In this context, an accurate evaluation of the glomerular filtration rate (GFR) during oncologic treatment is pivotal and is used to define surgery strategies, program prophylactic management of contrasted examinations, make decisions on cisplatin eligibility, and adjust drug prescriptions, particularly chemotherapy agents. Although the most commonly used equations to estimate GFR based on serum creatinine levels in clinical practice (Cockcroft-Gault, Modification of Diet in Renal Disease Study, and CKD Epidemiology Collaboration equations) have not been validated in patients with cancer in large prospective studies, there is increasingly evidence supporting the use of CKD Epidemiology Collaboration equation to assess the GFR in patients with cancer, including for the use of chemotherapy prescriptions. Many patients with cancer may have changes in nutrition status and clearance measurements such as exogenous filtration markers might be extremely useful when clinical decisions differ depending on the GFR level. Future perspectives include the advent of new serum GFR biomarkers such as cystatin C, beta-trace protein, and beta-2 microglobulin as well as the GFR assessment by measuring total kidney parenchymal volume through image examinations.

Onco-nephrology: an appraisal of the cancer and chronic kidney disease links

A bidirectional relationship has been observed for kidney disease and cancer. On the one hand, cancer is an important complication noted in kidney disease as well as a major cause of morbidity and mortality in this group. On the other hand, improved cancer treatment has prolonged survival, but also increased the development of acute and chronic kidney disease. The combination of cancer and kidney disease makes it challenging for clinicians to provide comprehensive and safe therapies for this group of patients. As such, clinicians caring for this group must develop expertise and become competent in the practice of a newly evolving subspecialty of nephrology known as 'onco-nephrology'. This brief narrative review will focus on the cancer risk in patients with underlying kidney disease, the therapies such as erythropoiesis-stimulating agents on cancer progression and other outcomes, and the appropriate dosing of anti-cancer agents in patients with underlying kidney disease.

Cancer-specific mortality in chronic kidney disease: longitudinal follow-up of a large cohort

BACKGROUND AND OBJECTIVES

Chronic kidney disease (CKD) is known to be associated with increased all-cause and cardiovascular mortality, but no large studies examined the cancer-specific mortality in non-dialysis-dependent CKD patients. Such outcome data are needed for proper allocation of resources and would help to develop better preventive services.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Between 1998 and 1999, 123,717 adults were recruited from four health screening centers in Taiwan. The estimated glomerular filtration rate was calculated using the four-variable Modification of Diet in Renal Disease Study equation for the Chinese. Mortality was ascertained by computer linkage to the national death registry after a median follow-up of 7.06 years. Cox proportional hazards regression models were used to estimate the impact of CKD on cancer-specific mortality.

RESULTS

A higher risk for overall cancer mortality was found in CKD patients compared with non-CKD patients (adjusted hazard ratio, 1.2). CKD was associated with increased mortality from liver cancer, kidney cancer, and urinary tract cancer, with an adjusted hazard ratio of 1.74, 3.3, and 7.3, respectively. A graded relationship between the severity of renal impairment and cancer mortality was also found.

CONCLUSIONS

Patients with CKD had a higher mortality risk of liver cancer, kidney cancer, and urinary tract cancer. This is the first large study that showed an inverse association between renal function and liver cancer mortality. The increased mortality could be caused by higher cancer incidence or worse response to cancer treatment. Future research is warranted to clarify the mechanism.

Head and neck malignancies in Croatian renal transplant recipients

Renal transplantation is associated with increased incidence of cancer. We reviewed a large series of renal transplant recipients to determine the incidence and outcome of patients with malignant changes located at the head and neck. A total of 1232 renal transplant recipients have been followed at Department of Dialysis University Hospital Centre Zagreb from 1972 to 2009. Demographic data, localization and disease outcome were evaluated in patients who developed cancer. Twenty one patients (1.7%) developed 27 head and neck malignancies. The average time from transplantation to development of cancer was 56.8 months. The mean length of follow-up was 9.4+/-4.8 years. Eighteen malignancies were cutaneous in origin and 9 were noncutaneous. Of cutaneous malignancies, 88.9% were basal cell carcinoma; one patient had Merkell-cell carcinoma and one patient developed squamous cell carcinoma. Six cases of basocellular skin cancer were recorded in one fair-skin patient. Noncutaneous malignancies involved the oral cavity (2 cases of Kaposi's sarcoma and one pharyngeal cancer) and the thyroid gland in 3 patients each. Two patients had post-transplant lymphoproliferative disorder occurring at the head and neck. One patient had brain tumor. Radical surgery, radiation, and/or chemotherapy were necessary in 33.3% of patients. Immunosuppression was reduced in all patients, and 12 patients were switched from the calcineurin-based immunosuppression to sirolimus. They all have stable graft function. None of the patients died from cancer. Immunosuppression was ceased in one patient with Kaposi's sarcoma who returned to dialysis and died 10 years later from heart failure. An increased incidence of cancer occurring in the head and neck was recorded. Careful skin examination and oral examination is mandatory for discovering cancer before dissemination. Sirolimus is safe alternative to calcineurin-based immunosuppression in patients who developed head and neck malignancies.

Colon and rectal cancer after renal transplantation

Increased cancer risk after renal transplantation is believed to be a consequence of continuous immunosuppression. However, the risk of colorectal cancer (CRC) after renal transplantation is controversial and has received limited study. Accumulating evidence suggests that colon and rectal cancers have different characteristics in the post-renal transplant patient (PRTP) and should be evaluated separately in transplant registries. This article reviews the current literature evaluating CRC diagnosed in PRTPs, focusing on clinical characteristics and treatment outcomes.

Pap smear findings in chronic renal failure patients compared with the normal population according to Bethesda 2001

Dialysis remains the most common treatment for end-stage renal disease (ESRD). Although the increased risk of cancer after renal transplant is well documented, there is less certainty about the risk of cancer in patients treated only with dialysis. From 1997 to 2002, 262 ESRD patients received a Pap test at Başkent University. The smears of 149 patients who had ESRD for more than 9 months were compared with the smears of 150 otherwise healthy patients. All of the Pap smears were re-examined according to Bethesda 2001 criteria. The mean age of the patients was 42.88 years. Regarding micro-organisms, no statistically significant difference between the groups were observed. In 36 Pap smears, a shift in flora suggestive of bacterial vaginosis was detected. There were statistically significant differences between the groups. When age was considered as a marker of atrophy, atrophy in patients younger than 50 years was statistically different between the groups. Also, we determined that the shift in flora suggestive of bacterial vaginosis and atrophy in patients aged younger than 50 years did not depend on the length of hemodialysis. Of 13 patients (4.3%) who had epithelial cell abnormalities there were not statistically significant differences between the groups. In conclusion, according to our study, CRF seems not to be a predictive factor for cervical cancer. Shift in flora suggestive of bacterial vaginosis and atrophy in patients aged younger than 50 years might be the natural effects of uremia, and they appear not to be dependent on the length of the hemodialysis period.

The prevalence of colorectal neoplasia in patients with end-stage renal disease: a case-control study

BACKGROUND AND PURPOSE

The scarcity of organs for transplantation has led to aggressive pretransplant evaluations. Many younger kidney transplant patients with end-stage renal disease, who would be ordinarily at average risk for colorectal cancer, undergo screening colonoscopy as part of this evaluation. The purpose of this study was to determine the prevalence of colorectal neoplasia in patients with end-stage renal disease who are potential transplant candidates.

MATERIALS AND METHODS

We performed a retrospective chart review analysis on 57 kidney transplant candidates who underwent pretransplant screening colonoscopy between August 1999 and December 2004. The control group was comprised of 60 age- and gender-matched subjects without end-stage renal disease who underwent routine screening colonoscopy.

RESULTS

The prevalence of polyps in end-stage renal disease patients was 37 vs 22% in the control group (p=0.07, not significant). None of the risk factors studied were found to predict the presence of polyps in the study group.

CONCLUSION

These results suggest that screening guidelines for colorectal cancer for the general population should be adequate for potential kidney transplant recipients.

Screening, diagnosis, and treatment of cancer in long-term dialysis patients

Some have suggested that the American Cancer Society guidelines for cancer screening be applied to patients who are on long-term dialysis and have used cancer screening as a means of assessing delivered preventive health care to patients with ESRD. However, cancer screening is effective only when it leads to survival benefit (usually expressed as days of life saved) without incurring high financial costs. Certain cancers such as human papillomavirus-associated cervical and tongue cancer and urologic malignancies are more common among dialysis patients, yet because the expected remaining lifetime of most dialysis patients is shorter than the time lived to develop malignancy, cancer screening in dialysis patients as applied to the general population is ineffective from the perspective of both cost and survival benefit. Cancer screening in dialysis patients is therefore best provided in an individual patient-focused manner. The occurrence, diagnosis, and treatment of cancer as well as issues related to cancer screening in dialysis patients are discussed.

Chromosomal damage and atherosclerosis. A protective effect from simvastatin

In uremic patients, the frequency of sister chromatid exchanges appears markedly higher than in the general population. Statins are well known for their pleiotropic effects, which are independent of any reduction in cholesterol circulating levels. The aim of the present study was to determine the effects of exposure to escalating doses of simvastatin on the sister chromatid exchange rate in cultured lymphocytes in order to identify the influence of statin on genomic damage. Peripheral lymphocytic samples for culture were obtained from 25 healthy volunteers, 20 patients with documented carotid atherosclerosis and 30 atherosclerotic patients on maintenance regular acetate-free biofiltration. Hemodialyzed patients had a greater percentage of high frequency cells (50%) than healthy controls (3%) and a significantly higher average number of sister chromatid (9.82+/-2.1 vs. 4.65+/-2.18). The subgroup of hemodialyzed patients with high plaque score values was characterized by significantly greater values for both sister chromatid exchanges rate and high frequency cells percentage. Our findings demonstrate that there is an association between sister chromatid exchanges and high frequency cells rate and atherosclerosis in acetate-free biofiltration patients. In cultures with added simvastatin, high frequency cells percentages and mean sister chromatid exchanges levels were significantly lower than in cultures with an added vehicle alone, the reduction occurring in a dose-dependent fashion, above all in cultures from end stage renal disease patients. The findings, moreover, demonstrate new effects of simvastatin, which appeared to mitigate the expression of genomic damage in our model. However, it is not yet clear whether this effect is due to the prevention of genomic damage or to the potentiation of the DNA repair capacity. Statins may therefore have an anti-atherogenic action partly ascribable to their ability to provide protection against the development of atherosclerotic plaque.

Protective effect of vitamin C on 8-hydroxy-2′-deoxyguanosine level in peripheral blood lymphocytes of chronic hemodialysis patients

BACKGROUND

This study focused on the effect of vitamin C on the 8-hydroxy-2'-deoxyguanosine (8-OHdG) level of cellular DNA, as well as 8-oxoguanine-DNA glycosylase 1 (hOGG1) and human MutT homologue (hMTH1) gene expression in peripheral blood lymphocytes of chronic hemodialysis patients.

METHODS

Sixty chronic hemodialysis patients (35 men and 25 women) were recruited to participate in a randomized, placebo-controlled study. Treatment order is block-randomized with intravenous sodium ascorbate (vitamin C, 300 mg) or placebo (0.9% saline), administered postdialysis three times a week. We evaluated 8-OHdG level, intracellular reactive oxygen species (ROS) production, and gene expression of hOGG1 and hMTH1 in peripheral blood lymphocytes by using high-performance liquid chromatography (HPLC) electrochemical detection method, flow cytometric analysis, and reverse transcription-polymerase chain reaction (RT-PCR), respectively.

RESULTS

A total of 51 patients completed the study (26 in placebo group and 25 in vitamin C group). Mean 8-OHdG levels significantly decreased in total subjects following 8 weeks of vitamin C supplementation (22.9 vs. 18.8/10(6) dG, P < 0.01). The decrease in 8-OHdG levels after vitamin C supplementation was also noted in the patients with ferritin <500 or > or =500 microg/L and transferrin saturation (TSAT) <50 or > or =50% (P < 0.05). But 8-OHdG levels had no significant changes in total patients or in the four subgroups of patients treated with placebo as compared to their baselines. Intracellular ROS production by lymphocytes from the four subgroups of patients, either spontaneous (P < 0.05) or phorbol-12-myristate-13-acetate (PMA)-stimulated (P < 0.001), was significantly reduced after 8 weeks vitamin C supplementation. Steady-state hOGG1 mRNA levels were significantly up-regulated at 24 hours after vitamin C administration (P < 0.05), but hMTH1 mRNA levels were not. The changes in the spontaneous and PMA-stimulated ROS production, and an up-regulation of hOGG1 mRNA expression were not observed in patients treated with placebo as compared to their baselines.

CONCLUSION

Vitamin C supplementation in chronic hemodialysis patients can reduce the lymphocyte 8-OHdG levels and intracellular ROS production, as well as up-regulate hOGG1 gene expression for repair. There is no compelling evidence for an in vivo pro-oxidant effect of vitamin C on lymphocyte DNA base oxidation, even in the status of increased iron stores.

Pretransplant evaluation of renal transplant candidates

Kidney transplantation should be strongly considered for all medically suitable patients with chronic and end-stage renal disease (ESRD). Improvements in outcomes after renal transplantation have resulted in a more liberal selection of patients. High-risk category patients including human immunodeficiency virus (HIV)-positive, highly sensitized patients, T-cell positive cross-match, and ABO blood group-incompatible patients are now considered potential renal transplant candidates. Unfortunately, the demand for kidney transplants far exceeds the supply of available organs, causing a persistent increase in the number of patients on the waiting list with a parallel increase in the waiting time for a cadaveric kidney transplant. This has 2 major consequences. First, patients on the waiting list are getting sicker and older. Second, living donors have assumed increasing importance in renal transplantation. Pre-existing morbidities including malignancies, cardiovascular disease, infections, and coagulopathies should be extensively evaluated before proceeding to transplantation. Special attention should be given to cardiovascular risk factors because the leading cause of death after renal transplant is cardiovascular disease. A full immunologic evaluation with ABO blood group determination, human leukocyte antigen (HLA) typing, screening for antibody to HLA phenotypes, and cross-matching need to be gathered before transplantation to avoid antibody-mediated hyperacute rejection or to proceed with specific protocols in highly sensitized or in positive T-cell cross-match patients. With the increased rate of donation from living donors, regular follow-up evaluation of kidney donors is recommended to detect hypertension or proteinuria in those who may develop it.

Increased oxidative damage to peripheral blood leukocyte DNA in chronic peritoneal dialysis patients

This study focuses on the extent of oxidative DNA damage in peripheral blood leukocytes of chronic peritoneal dialysis (CPD) patients. 8-Hydroxy 2'-deoxyguanosine (8-OHdG) contents in peripheral leukocyte DNA were measured by an HPLC-electrochemical detection method in 24 age- and sex-matched healthy subjects, 22 nondialyzed patients with advanced renal failure, and 42 CPD patients. Mean 8-OHdG content was the highest in CPD patients, followed by the nondialyzed patients, and then by the healthy subjects (19.4 versus 11.9 versus 8.3/10(6) dG; ANOVA P < 0.001). In nondialyzed subjects, peripheral leukocyte 8-OHdG contents inversely correlated with renal creatinine clearance (r = -0.772; P < 0.001). Deficiency of blood antioxidants in CPD and nondialyzed patients was expressed by the lower plasma levels of ascorbate, cholesterol-standardized alpha-tocopherol and whole-blood reduced glutathione, and the higher levels of whole-blood oxidized glutathione as compared with healthy subjects (ANOVA P < 0.05). Mean serum ferritin and iron levels and transferrin saturation were higher in the CPD patients than those in the nondialyzed patients and controls (ANOVA P < 0.05). Flow cytometric analyses of intracellular reactive oxygen species production of peripheral leukocytes showed that spontaneous production by granulocytes, as well as phorbol-12-myristate-13-acetate (PMA)-induced production by granulocytes, lymphocytes and monocytes, were the highest from CPD patients, followed by nondialyzed patients, and then by the healthy subjects (ANOVA P < 0.05). Forward stepwise multiple regression disclosed that uremia, PD treatment, spontaneous and PMA-induced reactive oxygen species production in leukocytes, and serum iron were the independent determinants of peripheral leukocyte 8-OHdG content (R(2) = 0.769; P < 0.001). In conclusion, profound increased 8-OHdG levels in peripheral leukocyte DNA occur in the course of chronic renal failure, gradually increase with its progression, and are further exacerbated by PD treatment.

Effect of human OGG1 1245C-->G gene polymorphism on 8-hydroxy-2'-deoxyguanosine levels of leukocyte DNA among patients undergoing chronic hemodialysis

The effects of the human OGG1 gene (hOGG1) 1245C-->G polymorphism on the 8-hydroxy-2'-deoxyguanosine (8-OHdG) contents of peripheral leukocyte DNA were investigated among chronic hemodialysis patients. First, the hOGG1 1245C-->G transversion was assessed, by using a PCR-restriction fragment length polymorphism method, among 210 hemodialysis patients and 156 healthy individuals. Second, the 8-OHdG contents in leukocyte DNA were measured, by using an HPLC-electrochemical detection method, for 112 hemodialysis patients and 112 age-, gender-, and genotype-matched healthy control subjects. The three genotypes (as dummy variables) and age, gender, dialysis duration, dialyzer membrane type, blood antioxidant levels, and iron parameters were used as independent variables and the natural logarithm of the leukocyte 8-OHdG concentration was used as a dependent variable in a forward, stepwise, multiple-regression model. The results demonstrated that the allelic frequency of hOGG1 1245G was 64.1% among 210 hemodialysis patients and 62.2% in the whole control population. The genotypic frequencies (CC/CG/GG ratio, 10%/51.9%/38.1%) for the hemodialysis patients did not differ significantly from those (16.7%/42.3%/41.0%) for the control subjects (P > 0.05, chi(2) test). The mean leukocyte 8-OHdG levels for the patients were significantly higher than those for the healthy control subjects (P < 0.001). Leukocyte 8-OHdG levels were further increased among patients with the 1245GG genotype, compared with patients with the 1245CG or CC genotype (P < 0.001, ANOVA), but levels were similar among healthy control subjects irrespective of the hOGG1 gene polymorphism. It was also observed that patients who underwent dialysis with cellulose membranes exhibited significantly higher leukocyte 8-OHdG levels than did patients who underwent dialysis with polymethylmethacrylate, polysulfone, or vitamin E-bonded membranes (P < 0.001, ANOVA). The multivariate regression analysis revealed that hOGG1 1245C-->G polymorphism and dialysis membrane type were the two independent predictors of 8-OHdG contents in leukocyte DNA from hemodialysis patients. This study demonstrated that the extent of oxidative DNA damage among chronic hemodialysis patients not only is influenced by overproduction of reactive oxygen species resulting from leukocyte contacts with complement-activating membranes and by impaired antioxidant defense mechanisms but also is genetically determined.

Secondary Hyperparathyroidism: Evidence for an Association with Papillary Thyroid Cancer

The association between primary hyperparathyroidism and nonmedullary thyroid malignancies is well known. There is also, however, some evidence for an association between secondary hyperparathyroidism (SHPT) and thyroid cancer. We report three patients in whom invasive papillary thyroid carcinoma (PTC) was diagnosed before (one case) or at the time of (two cases) parathyroidectomy for SHPT. Three women (ages 23, 54, and 64 years) presented with bone pain and pruritis typical of SHPT. All three patients had biopsy-proven parathyroid bone disease and elevated parathormone levels (664, 1674, and 2051 pg/mL). All underwent subtotal parathyroidectomy and total thyroidectomy without complications. Pathology revealed diffuse parathyroid hyperplasia with multifocal invasive papillary thyroid carcinoma (two cases) and follicular variant of papillary thyroid carcinoma (one case). Two cases were associated with metastatic disease to local lymph nodes. The patients received adjuvant radioactive 131I, and remained tumor free 24 to 36 months after surgery with complete resolution of SHPT. We conclude: 1) PTC may accompany SHPT, 2) PTCs associated with SHPT may be locally aggressive although usually they are early tumors, 3) surgeons need to have an index of suspicion for thyroid tumor when operating on patients with SHPT, and 4) routine removal of the thymus as part of the operation for SHPT may have a secondary benefit in diagnosing PTC in the occasional patient.

Changes in conjugated linoleic acid and its metabolites in patients with chronic renal failure

BACKGROUND

Conjugated linoleic acid (CLA) is a mixture of isomers of linoleic acid with conjugated double bonds that constitutes the most abundant fatty acid with conjugated dienes (CDs) in humans. CLA, erroneously considered in the past as a product of lipoperoxidation, has a dietary origin and has shown to possess anticarcinogenic and anti-atherogenic activity, mainly in animal studies. CLA can be metabolized to conjugated linolenic acid (CD18:3) and to conjugated eicosatrienoic acid (CD20:3) and these metabolites may be implicated in CLA activity. Because of the presence of dyslipidemia and the high incidence of cardiovascular and neoplastic diseases in uremic patients, we evaluated CLA and its metabolites in these patients in order to evaluate their metabolism and site distribution.

METHODS

We measured CLA, CD18:3, CD20:3, CD fatty acid hydroperoxides (lipoperoxidation products), and linoleic acid in the plasma, adipose tissue, and red blood cell (RBC) membranes by using high-pressure liquid chromatography in the following groups: (1) 23 chronic renal failure (CRF) patients with creatine clearance (CCr)> 10 mL/min (26.2 +/- 16.7); (2) 21 end-stage CRF patients in conservative treatment with CCr <10 mL/min (6.8 +/- 1.8); (3) 30 hemodialysis (HD) patients; and (4) 30 healthy controls.

RESULTS

The incorporation of CLA, CD18:3, and CD20:3 in RBC membranes was significantly reduced in group 1 and was even more reduced in groups 2 and 3. CLA significantly increased both in the plasma and adipose tissue of end-stage CRF patients only. CD18:3 and CD20:3 did not change in the plasma and adipose tissue of any group. No significant changes in linoleic acid and CD fatty acid hydroperoxides were found.

CONCLUSIONS

The alterations of CD in CRF patients are not due to lipoperoxidation. The increased levels of CLA in plasma and adipose tissue of end-stage CRF patients may be due either to a reduced metabolization of CLA to CD18:3 and CD20:3, or to an altered site distribution with reduced incorporation in cellular membranes and accumulation in the plasma and adipose tissue. The clinical significance of these changes remains to be investigated.

Prognosis of anti-hepatitis C virus antibody-positive patients on regular hemodialysis therapy

The prevalence of hepatitis C virus (HCV) infection is high in patients who are on chronic hemodialysis, but the role of HCV infection and HCV-related liver disease in the mortality of these patients has not been shown. Therefore, we conducted a prospective cohort study of 1470 patients who were on chronic hemodialysis (17 to 89 yr old) from 16 dialysis centers in Japan. Among them, 276 patients (18.8%) were positive for anti-HCV antibodies and 1194 patients were negative. The patients were followed for 6 yr from 1993 to 1999. Only one case, a patient from the anti-HCV-antibody-positive group, was lost to the follow-up during this period. The mortality was higher in the anti-HCV-antibody-positive group (91 of 276 patients died) than in the anti-HCV-antibody-negative group (277 of 1193 died) (33.0% versus 23.2%, P< 0.01). A Cox proportional hazard examination showed that positivity for anti-HCV antibodies was one of the risk factors for death with an adjusted relative risk of 1.57 (95% confidence interval, 1.23 to 2.00). As a cause of death, hepatocellular carcinoma and liver cirrhosis were significantly more frequent in the anti-HCV-antibody-positive patients than in the anti-HCV-antibody-negative patients (5.5% versus 0.0%, P< 0.001; 8.8% versus 0.4%, P< 0.001, respectively). These findings show that the mortality is increased in anti-HCV-antibody-positive patients who are on chronic hemodialysis. Hepatocellular carcinoma and liver cirrhosis are factors that may influence the mortality.

Effect of vitamin E-bonded membrane on the 8-hydroxy 2'-deoxyguanosine level in leukocyte DNA of hemodialysis patients

BACKGROUND

8-Hydroxy 2'-deoxyguanosine (8-OHdG) of leukocyte DNA has been identified as a surrogate marker of oxidative stress in chronic hemodialysis (HD) patients. In this study, we focused on the determinants of the 8-OHdG level in leukocyte DNA of HD patients. We further investigated the influence of vitamin E-modified, regenerated cellulose (CL-E) membrane on the oxidative DNA damage, intracellular reactive oxygen species (ROS) production of granulocytes, and plasma alpha-tocopherol concentration.

METHODS

8-OHdG content in cellular DNA of leukocytes was measured by a high-performance liquid chromatography-electrochemical detection (HPLC-ECD) method. Intracellular production of ROS, H2O2 and O2-. were analyzed by flow cytometry in leukocytes with and without phorbol-12-myristate-13-acetate (PMA) stimulation before dialysis, as well as at 15 and 30 minutes of dialysis. Plasma alpha-tocopherol concentration was measured by a HPLC method, and the value of alpha-tocopherol was corrected by total blood lipid concentration.

RESULTS

In the prospective cross sectional study, the mean 8-OHdG level in leukocyte DNA was equally lower in the patients of the CL-E, polymethylmethacrylate (PMMA), and polysulfone (PS) groups as compared with the cellulosic group (ANOVA, P < 0.001). The leukocyte 8-OHdG level correlated negatively with plasma alpha-tocopherol and blood lipid-adjusted plasma alpha-tocopherol, but correlated positively with serum iron and percentage of transferrin saturation. Forward stepwise multiple regression showed that dialysis membrane type, serum iron, and blood lipid-adjusted plasma alpha-tocopherol were the independent determinants of the leukocyte 8-OHdG level in HD patients. Like synthetic membranes, granulocyte ROS production was less augmented during dialysis with the CL-E membrane as compared with the cellulose membrane. Exposure to cellulose membrane impaired intracellular ROS production of granulocytes in response to PMA challenge, whereas the CL-E and synthetic membranes improved the granulocyte responsiveness to PMA. In the longitudinal cross-over study, the 8-OHdG level significantly decreased, and blood lipid-adjusted plasma alpha-tocopherol increased after switching the cellulose membrane to CL-E or synthetic membrane for eight weeks. In contrast, the 8-OHdG level dramatically rose, and blood lipid-adjusted plasma alpha-tocopherol declined after shift of CL-E or synthetic membrane to the cellulose membrane.

CONCLUSIONS

CL-E membrane exhibited biocompatible and bioactive characteristics. Like synthetic membranes, treatment with a CL-E dialyzer effectively reduced the 8-OHdG content in leukocyte DNA, suppressed intracellular ROS production of granulocytes, and preserved the plasma level of vitamin E. It could further improve granulocyte responsiveness to a PMA challenge. Reduced DNA damage and improved immune function of leukocytes may reduce the cancer and infection risks in chronic HD patients.

Papillary microcarcinoma of the thyroid gland in renal transplant patients

Among organ transplant recipients there is a world wide increase in the number of de novo tumors as well as a decrease in the time of the first appearance after the transplantation. Between 1973 and the 31st of August 1999 1709 cadaver renal allograft transplantations were performed in our Department. Four thyroid cancers were detected among the renal transplanted patients. Two of them proved to be papillary microcarcinomas. Although the elevated risk of thyroid cancers is well established in the literature papillary microcarcinomas have never been reported before in an immunosuppressed patient. Authors highlight that the thyroid gland should always be carefully checked in organ transplant recipients, since better survival might be achieved even in the immunosuppressed population. Metastatic tumor is relatively benign which is in correlation with the literature, but there has been little experience in organ transplanted patients so far.

Cancer in patients on dialysis for end-stage renal disease: an international collaborative study

BACKGROUND

Previous studies have suggested that the frequency of cancer is higher in patients with end-stage renal disease (ESRD) than in the general population, but have not established whether this increase is confined to certain cancers or to certain categories of ESRD patients. The aim of this study was to examine the risk of cancer in a large cohort of patients treated by dialysis but not transplantation.

METHODS

We assembled a cohort of 831,804 patients who received dialysis during the period 1980-94 for ESRD in the USA, Europe, Australia, or New Zealand. We compared the observed frequency of cancer among these patients during 2,045,035 person-years of follow-up with the frequency of cancer in the respective background populations.

FINDINGS

During average follow-up of 2.5 years, 25,044 (3%) of 831,804 patients developed cancer compared with an expected number of 21,185 (standardised incidence ratio 1.18 [95% CI 1.17-1.20]). We observed a higher risk of cancer in patients younger than 35 years (3.68 [3.39-3.99]), and the risk gradually decreased with increasing age. High risks were observed for cancer of the kidney (3.60 [3.45-3.76]), bladder (1.50 [1.42-1.57]), and thyroid and other endocrine organs (2.28 [2.03-2.54]). Excess cancers appeared in several organs for which viruses have been suspected as causative agents, whereas cancers of the lung, colorectum, prostate, breast, and stomach were not consistently increased.

INTERPRETATION

The overall risk of cancer is increased in patients with ESRD, and the distribution of tumour types resembles the pattern seen after transplantation (although we have no data to make the comparison with skin cancer). The excess risk can largely be ascribed to effects of underlying renal or urinary-tract disease, or of loss of renal function, on the kidney and bladder, and to increased susceptibility to viral carcinogenesis. The relative risk, which is especially high in younger patients, gradually diminishes with age.