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

[Malignant neoplasms and kidney transplantation]

Together with cardiovascular disorders and metabolic changes, malignant diseases are considered as great challenges in clinical transplantation. As far as long-term function of transplanted organs is concerned, an impact of malignancies is obvious. However, it is important to distinguish between neoplastic disease originating from preexisting lesions in the transplanted organs and de novo graft tumors. Further, there is also a high risk of developing malignant disease during the dialysis, likely due to potential harmful metabolic changes associated with this procedure. After curative management of tumors in such patients, an interval of 2 years for surveillance should be adhered to before patients are put back on the waiting list. The overall risk of transmission of a malignant disease with the transplanted graft has been considered to be as low as <0.2%. In this context, and considering the continual shortage of donated organs, there is an international consensus about the use of kidney grafts with a history of small tumors (<2 cm in diameter und low-grade, i.e., G1). However, the lesions should have been removed with subsequent histopathologic characterization before the acceptance of the organ for transplantation. Early diagnosis and management of de novo malignant disease in transplant patients is crucial for the prognosis of graft function and patient survival. Genitourinary malignancies are frequent among de novo malignancies in transplanted patients. Thus, there is a need for clearly structured concepts for screening of transplant patients in order to detect early malignancies. The incidence of malignant disease correlates directly with the extent of immunosuppression in patients with end-stage renal disease (ESRD) on dialysis, as well as after transplantation with life-long immunosuppressant therapy. In addition, also geographic factors seem to play a role in the differential incidence of tumors among different populations. For instance, the highest incidence of malignancies among immunosuppressed patients has been observed in Australia followed by the USA and Europe. This might be due to the high incidence of de novo skin cancer, which has been linked to the extent of UV exposure.

The seroprevalence of human papillomavirus by immune status and by ethnicity in London

Background

The natural history of cutaneous HPV is unclear and in particular, seroprevalence among individuals with different levels of immune function and ethnicity is unknown. As part of a study of cutaneous squamous cell carcinoma (SCC) and HPV among organ transplant recipients (OTR) from London, we investigated the seroprevalence and risk factors for 34 HPV types (detected using Luminex technology) among 409 OTR patients without skin cancer (243 Caucasians and 166 non-Caucasians), 367 individuals with end stage renal failure on dialysis (222 Caucasians and 145 non-Caucasians) and 152 immunocompetent (IC) individuals without skin cancer (102 Caucasians and 50 non-Caucasians) to compare the HPV seroprevalence in patients with differing immune status and ethnicity. In total, seroprevalence data from 928 individuals, all from London, was available.

Results

Overall, no difference between HPV seroprevalence by immune status was observed (P = 0.3) among Caucasian or among non-Caucasian individuals, with seroprevalence varying from 87% to 94% across different immune status and ethnic groups. Those individuals seropositive to multiple types of one genus were more likely to be seroreactive to multiple types of another genus, independent of immune status or ethnicity. Lower seroprevalence for gammaHPV 4, and to a lesser extent gammaHPV 48, were observed among OTR compared to IC and dialysis patients. Higher seroprevalence against antibodies to betaHPV 93 were detected more frequently in non-Caucasians than Caucasians whereas muHPV 1 and, to a lesser extent, gammaHPV 4 were found more frequently among Caucasians - these findings were independent of immune status. Within non-Caucasian subgroups, the seroprevalence of 8 HPV (alpha-mucosal HPV16 and 13, alpha-cutaneous HPV7 and 2, betaHPV8, 17, 23 and 38) was significantly (P < 0.02) higher in Black compared to Asian patients. HPV16 being sexually transmitted, this might suggest a potential sexual route of transmission for some beta HPV types.

Conclusion

We did not observe major disturbance in antibody response between immunocompetent, dialysis and OTR individuals, but significant differences in HPV seroprevalence were identified according to ethnicity. Further research is needed to clarify the natural history of cutaneous HPV, particularly given the growing research interest in its possible role in the pathogenesis of cutaneous SCC.

Decreased CD3+CD16+ natural killer-like T-cell percentage and zeta-chain expression accompany chronic inflammation in haemodialysis patients

AIM

Clinical and experimental data indicate a deficient immune response in haemodialysis (HD) patients. Natural killer-like (NKL) T cells express on their surface both the T-cell antigen receptor (TCR) and a diverse set of NK-cell receptors (NKR) and share properties of both T cells and NK cells. zeta-Chain phosphorylation is an early event that follows TCR activation or some NKR activation. The zeta-chain of both T cell and NK cells is downregulated in many chronic inflammatory states, HD included. In the present study, NKL T-cell percentage and zeta-chain expression in HD patients were evaluated.

METHODS

Thirty-three stable HD patients and 30 healthy volunteers were enrolled into the study. NKL T-cell percentage and NKL T-cell zeta-chain mean fluorescence intensity (MFI) were evaluated with flow cytometry. The inflammatory markers C-reactive protein, interleukin-6 and tumour necrosis factor-alpha were measured in the serum by means of enzyme-linked immunosorbent assay.

RESULTS

All the evaluated markers of inflammation were increased in HD patients. In these patients, NKL T-cell percentage (1.71 +/- 1.69% vs 3.94 +/- 3.86%) and zeta-chain MFI (3.66 +/- 2.79 vs 7.03 +/- 7.91) were decreased.

CONCLUSIONS

NKL T-cell percentage and zeta-chain expression is decreased in HD patients. Taking into consideration the continuously increasing age of the HD patients and that normally NKL T-cell numbers increase with age counteracting the impaired T-cell and NK-cell function accompanying advancing age, the above NKL T-cell disturbances could contribute to the impaired immune response in this population. Measures towards alleviating chronic inflammation could partially restore NKL T-cell impairment.

[What tests are necessary before registration on the kidney transplant waiting list?]

Before registering a patient on the kidney transplant waiting list, the medical file should be carefully studied looking for factors that may complicate the transplantation. Knowledge of the patient's history and the clinical examination will guide the choice of complementary examinations. The objectives of pretransplantation explorations are : 1) preventing graft rejection ; 2) ensuring that arterial and venous anastomoses are possible ; 3) ensuring that urine can be drained ; 4) preventing post-transplantation infections ; 5) not performing a transplantation on a subject with cancer ; and 6) avoiding any post-transplantation cardiovascular events. The list of the necessary explorations for renal transplantation should be as simple as possible so that registration on the transplant waiting list is not delayed, while being as complete as possible to prevent any complications that may compromise the results. It should be individualized to each patient.

The pattern of excess cancer in dialysis and transplantation

BACKGROUND

After transplantation, cancer risk varies from no increase for several common cancers to a many-fold increase for a number of, chiefly virus-associated, cancers. The smaller excess of cancer in dialysis has been less well described, but two studies suggested that impaired immunity might be responsible.

METHODS

In a population-based cohort study of 28 855 patients who received renal replacement therapy (RRT), we categorized incident cancers as end-stage kidney disease (ESKD) related, immune deficiency related, not related to immune deficiency, or of uncertain status, according to whether they were, or were not, increased in published reports of cancer in ESKD prior to starting RRT, organ transplantation or human immunodeficiency virus infection. Standardized incidence ratios for, and excess burdens of, cancer were calculated for all persons normally resident in Australia starting treatment by dialysis or renal transplantation from 1982 to 2003.

RESULTS

The risk for ESKD-related cancers was increased 4-fold in dialysis and during transplant function. For immune deficiency-related cancers, the increase was 1.5 (95% CI 1.3-1.6) times in dialysis, and 5-fold after transplantation. ESKD- or immune deficiency-related cancers contributed to approximately 90% of the excess burden of cancer, 48% and 36%, respectively, in dialysis, and 10% and 78% after transplantation. The remaining excess malignancy was contributed by cancers whose relationship with ESKD and immune deficiency is not yet certain.

CONCLUSIONS

In RRT, the increase in cancer is restricted, largely if not wholly, to cancers with origins in ESKD or related to immune deficiency. For the former, the cancer risk is similar in dialysis and transplantation, but for immune deficiency-related cancers, the relative risk is much greater after transplantation.

Effects of Hemodialysis, Dialyser Type and Iron Infusion on Oxidative Stress in Uremic Patients

Uremic patients undergoing hemodialysis (HD) are considered to face an elevated risk for atherosclerosis and cancer. This has been attributed in part to an increased oxidative stress. In this pilot study, oxidative cell damage in blood of HD-patients was compared to those of controls: total DNA damage (basic and specific oxidative DNA damage), modulation of glutathione levels (total and oxidized glutathione) and of lipid peroxidation were monitored via the Comet assay (with and without FPG), a kinetic photometric assay and HPLC quantification of plasma malondialdehyde (MDA), respectively. In some samples, leukocytes were analysed for malondialdehyde-deoxyguanosine-adducts (M1dG) with an immunoslot blot technique. HD-patients (n=21) showed a significant increase of total DNA damage (p<10(-12)), compared to controls (n=12). In a subset of patients and controls, GSSG levels and M1dG, however, only increased slightly, while tGSH and MDA levels did not differ. The influence of different low flux HD-membranes was tested in a pilot study with nine patients consecutively dialysed on three membrane types for four weeks each. In addition to the individual disposition of the patient, the dialyser membrane had a significant impact on oxidative stress. Total DNA damage was found to be almost identical for polysulfone and vitamin E coated cellulosic membranes, whereas a slight, but significant increase was observed with cellulose-diacetate (p<0.001). In patients receiving iron infusion during HD, MDA-formation (n=11) and total DNA damage (n=10) were additionally increased (p<0.005). Our results show an increased oxidative damage in HD-patients, compared to healthy volunteers. Significant influences were found for the dialyser membrane type and iron infusion.

Light chains: heavy burden in kidney transplantation

Plasma cell dyscrasias are frequently encountered malignancies which are often associated with kidney disease through the production of monoclonal immunoglobulin (Ig). Recent advances in the field include the availability of an assay for free light chains, the introduction of new agents which more effectively target malignant plasma cells, and refinements in the application of stem-cell transplantation. Well-selected patients with plasma cell dyscrasias whose monoclonal Ig is well controlled may be candidates for kidney transplantation. Kidney transplant patients with allograft dysfunction from recurrent or de novo monoclonal Ig deposition can be successfully identified and treated with these new approaches.

Chronic renal failure induces genetic instability in multiple organs of Wistar rats

BACKGROUND

Taking into consideration the strong evidence for a relationship between DNA damage and carcinogenesis, the aim of this study was to investigate whether blood, liver, heart, kidney and brain are particularly sensitive organs for DNA damaging during chronic renal disease by the single-cell gel (comet) assay to predict genetic instability induced by this pathological condition.

METHODS

A total of 18 male Wistar rats were divided into two groups: negative control (n = 8) and experimental (n = 10), in which was submitted to the 5/6 renal mass ablation by ligation of two or three branches of the left renal artery and total right nephrectomy during 8 weeks.

RESULTS

The results showed that chronic renal disease was able to induce genetic damage in blood, heart, liver and kidney cells as depicted by the mean tail moment. No genetic damage was induced in brain cells, i.e. no significant statistically differences (P > 0.05) were noticed when compared to negative control.

CONCLUSION

In conclusion, our results suggest that chronic renal failure could contribute to the damage of DNA at all organs evaluated, except to the brain cells. As DNA damage is an important step in events leading to carcinogenesis, this study represents a relevant contribution to the correct evaluation of the potential health risks associated with kidney disease.

Prostate cancer screening and treatment in the transplant population: current status and recommendations

PURPOSE

We reviewed the current status of and recommendations for prostate cancer screening and treatment in the solid organ transplant population.

MATERIALS AND METHODS

We performed a MEDLINE search to identify published data regarding prostate cancer screening, risk, treatment and outcomes in the solid organ transplant population. The literature was reviewed and summarized.

RESULTS

Most data regarding outcomes of prostate cancer treatment in the transplant population are limited to case reports and small series, and primarily involve renal insufficiency. It does not appear that the development or natural history of prostate cancer is significantly affected by organ failure or subsequent transplantation. Thus, prostate specific antigen testing and screening protocols can be extrapolated from the general population. However, the balance of comorbid diseases and estimated limitations in life expectancy must be carefully considered, and emphasis should be placed on risk assessment. Prostatectomy appears to be feasible with outcomes comparable to those in the non-transplant population, while data regarding the use of radiation therapy are limited.

CONCLUSIONS

The expansion of organ transplant criteria, including older donors and recipients, combined with improved allograft survival has enhanced the relevance of prostate cancer screening and treatment in this group. Greater awareness of the issues surrounding prostate cancer incidence, detection and natural history should promote improved data collection, screening and treatment of prostate cancer in the transplant population.

End-stage renal failure and regulatory activities of CD4+CD25bright+FoxP3+ T-cells

BACKGROUND

The defensive immune system in patients with end-stage renal failure is impaired at multiple levels. This state of immune incompetence is associated with continuous activation of the immune system. An additional explanation for this state of activation may be the disturbed function of CD4(+)CD25(bright+)FoxP3(+) regulatory T-cells.

METHODS

The phenotype and function of peripheral regulatory T-cells from patients with end-stage renal failure (N = 80) and healthy controls (N = 17) was studied by flow cytometry, RT-PCR and mixed lymphocyte reaction. Patients were on haemodialysis (N = 40), peritoneal dialysis (N = 26) or not treated with dialysis yet (N = 14). The latter group had a glomerular filtration rate of <20 ml/min/ 1.73 m(2).

RESULTS

The basal IL-2 mRNA level was high in patient-PBMC (P = 0.0002 versus healthy controls). The absolute number of CD4(+)CD25(bright+) T-cells was low in patients (P < 0.05 versus healthy controls). Furthermore, proliferation of patient-PBMC upon allogeneic stimulation was impaired (P < 0.0001 versus healthy controls). The regulatory function of CD4(+)CD25(bright+) T-cells was determined in the setting of direct allorecognition. First, the effect of depletion of CD25(bright+) cells from patient-PBMC on proliferation was low. Second, co-culture of CD25(bright+) cells with CD25(neg/dim) cells (1:10 ratio) showed impaired regulatory function (P < 0.001 versus healthy controls), which was especially pronounced in patients on dialysis. The FOXP3 mRNA level was also low upon stimulation (P = 0.0002 versus healthy controls).

CONCLUSIONS

In line with previous studies, we observed an overactivated but functionally compromised immune system in patients with end-stage renal failure. It now appears that in this setting, regulation by CD4(+)CD25(bright+)FoxP3(+) T-cells is also impaired.

Irinotecan in Cancer Patients with End-Stage Renal Failure

Objective:

To observe and report on the pharmacokinetics of irinotecan in a patient with end-stage renal failure (ESRF) who was undergoing hemodialysis.

Case Summary:

A 64-year-old man with metastatic colorectal cancer who was on hemodialysis was treated with Irinotecan 50 mg/m2 weekly for 3 weeks, followed by 1 week with no treatment. As the drug was well tolerated, the dosage was increased to 80 mg/m2 after 2 cycles. Diagnostic testing of a hepatic lesion after 2 and 6 treatment cycles showed stable disease. The carcinoembryonic antigen value decreased to 40% of its pretreatment level. Pharmacokinetically, our patient had a lower apparent clearance and a higher maximum concentration of the active metabolite SN-38 (130 L/h/m2, maximum concentration 0.4 μg/L per mg of irinotecan) compared with published values from patients with normal renal function. Removal of irinotecan and its metabolites by hemodialysis was negligible.

Discussion:

The reason for the unexpectedly low clearance of SN-38 in our patient remains unclear. We speculate that inhibition of the OATP1B1 transporter by uremic toxins could be an explanation. Such a mechanism would explain excessive irinotecan toxicity, as reported in previous case reports of patients undergoing hemodialysis.

Conclusions:

We conclude that approximately two-thirds of the standard weekly irinotecan dosage regimen should be considered in patients with ESRF.

Cancer in patients on chronic dialysis in Korea

The study of cancer in patients treated with dialysis in Korea has not been reported. The aim of this study was to investigate the incidence and mortality of cancer among patients on dialysis in Korea. The study subjects were 106 cancer patients (2.3%) out of 4,562 end-stage renal disease (ESRD) patients maintained on hemodialysis (HD) or peritoneal dialysis (PD) at Yonsei University Health System from 1996 to 2005. We excluded patients in whom the diagnosis of cancer preceded dialysis or those who received renal allograft or started dialysis after renal allograft. Seventy-three (69%) of our subjects were male and 33 (31%) were female. The mean age at the time of cancer diagnosis was 57.9+/-11.7 yr. The mean time from the start of dialysis to the diagnosis of cancer was 75.2+/-63.9 months. The most common cancer site was gastrointestinal tract (GIT) (51%) followed by urinary tract (20%), lung (8%), and thyroid (7%). Sixty nine percent of the total mortality was due to cancer. The mean time from diagnosis to death was 2.9+/-2.5 yr. In ESRD patients with cancer, there were no significant differences in mortality rates by dialysis modality. In ESRD patients, the most common cancer was GIT cancer followed by urinary tract cancer. Therefore, careful surveillance of these cancers in ESRD patients is highly recommended.

Kinetics of hepatitis B virus load and haemodialysis: a prospective study

The control of the spread of hepatitis B virus (HBV) infection within dialysis units has been an important goal in the management of patients on regular dialysis but infected patients continue to enter the dialysis system. It is evident that HBV viraemia in hepatitis B surface antigen (HBsAg)-positive patients on dialysis is low but it remains unclear whether haemodialysis per se can contribute to viral load reduction in such patients. HBV DNA was determined in 40 HBsAg-positive patients on maintenance haemodialysis immediately before and at the end of a 4-h haemodialysis session. The same measurements were repeated 48 and 72 h later. Twenty (50%) of 40 HBsAg-positive patients had detectable HBV DNA in serum. Detectable HBV DNA in serum was not predicted by demographic, clinical or biochemical parameters. HBV load decreased in the majority of patients after haemodialysis, although the difference was not significant (29 390 +/- 48 820 vs 23 862.8 +/- 4 350 copies/mL, NS). There was a strong relationship between mean HBV DNA levels before dialysis and absolute reduction of HBV DNA during haemodialysis sessions (r = 0.75, P = 0.0001). No difference occurred in the magnitude of change in HBV DNA titre when comparing cellulosic to synthetic membranes. Haemodialysis per se leads to a reduction in HBV load in HBsAg-chronic carriers on maintenance dialysis. This phenomenon could explain the low viral loads in these patients. Prospective studies are in progress to identify the mechanisms responsible for reduction in HBV load during haemodialysis.

Managing cancer risk and decision making after kidney transplantation

Kidney transplant recipients are at higher risk of cancer at most sites, and cancer after transplantation causes considerable morbidity and mortality. To optimize long-term patient outcomes, clinicians balance the prospect of graft failure and dialysis, with competing risks of diabetes, cardiovascular and cerebrovascular disease and the risk of malignancy. In this paper we critically examine the assumptions underpinning primary prevention, immunization, chemoprevention and screening programs, and highlight considerations when applying evidence to the kidney transplant population, and suggest a clinical research agenda that aims to define a rational approach to managing posttransplant cancer risk.

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.

Beyond anemia: the clinical impact of the physiologic effects of erythropoietin

Although we have known that oxygen tension affects erythrocyte production since the 19th century, we have only recently begun to understand many subtleties of erythropoietin (EPO) physiology. EPO administration has allowed hundreds of thousands of patients to avoid transfusions. With the beneficial effects so apparent a detailed understanding of the full clinical physiology of this plasma factor seemed less important. However, the unanticipated increase in mortality found in recent randomized studies is prompting a reassessment of this view. We will review what is known about the physiology of this plasma factor that, it is now clear, is more than just an erythrocyte production factor.

Benfotiamine reduces genomic damage in peripheral lymphocytes of hemodialysis patients

Hemodialysis patients have an elevated genomic damage in peripheral blood lymphocytes (PBLs) and an increased cancer incidence, possibly due to accumulation of uremic toxins like advanced glycation end products (AGEs). Because the vitamin B1 prodrug benfotiamine reduces AGE levels in experimental diabetes, and dialysis patients often suffer from vitamin B1 deficiency, we conducted two consecutive studies supplementing hemodialysis patients with benfotiamine. In both studies, genomic damage was measured as micronucleus frequency of PBLs before and at three time-points after initiation of benfotiamine supplementation. AGE-associated fluorescence in plasma, and in the second study additionally, the antioxidative capacity of plasma was analyzed. Benfotiamine significantly lowered the genomic damage of PBLs in hemodialysis patients of both studies independent of changes in plasma AGE levels. The second study gave a hint to the mechanism, as the antioxidative capacity of the plasma of the treated patients clearly increased, which might ameliorate the DNA damage.

Hepatitis C infection in patients with chronic kidney disease

The management of hepatitis C virus (HCV)-infected patients with chronic kidney disease (CKD) is complex and represents a particular concern since numerous issues, such as antiviral therapy in dialysis patients and post renal transplant, and prevention of HCV spread within dialysis units, remain unresolved. An enormous body of literature has been published on HCV in the CKD population; however, clinical evidence on important issues is mostly based on uncontrolled clinical trials or retrospective surveys. The aim of this paper is to provide a systematic review of the literature. Responses to the critical issues have been developed by a consensus of experts, endorsed by the Italian Association for the Study of the Liver (AISF) and some clinical recommendations have been added.

Breast cancer screening in women with chronic kidney disease: the unrecognized effects of metastatic soft-tissue calcification

Patients with chronic kidney disease (CKD) or end-stage renal disease (ESRD) are known to develop metastatic soft-tissue calcification, secondary to hyperparathyroidism, in tissues including the breast. Such calcifications in women could pose a problem for interpretation of mammograms, since they are thought to mimic malignant lesions and interfere with differentiation of benign from malignant disease. Investigation of this issue is important to provide high-quality, accurate breast care to women with CKD or ESRD, but little evidence is so far available. In a systematic review of the literature on the types and patterns of breast calcifications, we found only three studies that examined metastatic soft-tissue calcifications of the breast. The studies did, however, confirm that women with CKD or ESRD have a higher frequency of breast calcification than women with normal kidney function. The two older studies reported that these breast calcifications are not associated with malignancy, but the later study reported a raised rate of suspicious breast calcification among women with ESRD receiving hemodialysis, leading to an increased biopsy referral rate. In this Review we discuss the strengths and limitations of the available data and whether mammography is recommended in women with CKD or ESRD.

Hepatitis B virus infection and the dialysis patient

Prevention of nosocomial transmission of hepatitis B virus (HBV) has been a signal achievement in the management of chronic kidney disease. The rate of serum hepatitis B surface antigen (HBsAg) seropositivity in patients on maintenance hemodialysis in the developed world is currently low (0-10%) but outbreaks of acute HBV infection continue to occur in this setting. The prevalence of HBV infection within dialysis units in developing countries appears higher (2-20%) based on relatively few reports. Although data are limited, HBV infection in dialysis population diminishes survival; HBV viral load in HBsAg-positive dialysis patients is reportedly low and stable over time. Updated recommendations for the management of HBsAg chronic carriers on maintenance dialysis have been issued. No rigorously controlled treatment trials for treatment of hepatitis B with either interferon or lamivudine therapy in dialysis patients are currently available.

Hepatitis B viral infection in maintenance hemodialysis patients: a three year follow-up

AIM

To observe the prevalence of hepatitis B virus (HBV) infection in maintenance hemodialysis patients.

METHODS

Eighty-eight hemodialysis patients who had been receiving hemodialysis regularly for an average of 39.45 +/- 7.57 (range from 36 to 49) mo were enrolled in this study. HBV markers were measured in these patients before hemodialysis and in 100 healthy controls by the chemiluminescent microparticle immunoassay (CMI) method in order to compare the incidence of HBV infection in hemodialysis patients versus normal healthy people. All patients were then divided into two groups: patients positive for HBV markers (i.e. those positive for HBsAg, anti-HBc, HBeAg, anti-HBe, with or without positive anti-HBs) (n = 33), and patients negative for HBV markers (including those only positive anti-HBs) (n = 55). The following information was obtained for all patients: socio-demographic data, number of blood transfusions and some laboratory investigations. After 39.45 +/- 7.57 mo follow-up, HBV markers were measured in these patients by CMI.

RESULTS

The incidence of HBV infection in maintenance hemodialysis patients was 37.5%, which was higher than in controls (9%). In the patients positive for HBV markers, there were 13 patients (39.4%) who had a history of blood transfusion, which was more than the number [12 (21.8%), P = 0.04] of patients negative for HBV markers. Eight of the 88 patients negative for HBV markers turned out to be positive, while three of the 33 patients positive for HBV markers turned out to be negative. There was no cirrhosis of the liver or hepatoma occurring in these patients.

CONCLUSION

Maintenance hemodialysis patients have a higher risk of HBV infection than the average population. The number of blood transfusions is associated with an increased prevalence of HBV. While it is hard for hemodialysis patients to eliminate HBV, the prognosis of patients with positive HBV markers is good.

Late onset of bladder urothelial carcinoma after kidney transplantation for end-stage aristolochic acid nephropathy: a case series with 15-year follow-up

BACKGROUND

Aristolochic acids are nephrotoxins and predispose to upper-tract urothelial carcinoma. The risk of bladder urothelial carcinoma after kidney transplantation and its relationship to upper-tract urothelial carcinoma is not well defined.

STUDY DESIGN

Case series.

SETTING & PARTICIPANTS

Single-center cohort of 38 women given kidney transplants for end-stage aristolochic acid nephropathy.

OUTCOMES & MEASUREMENTS

The prevalence of upper urinary tract urothelial carcinoma was determined by collecting pathological results of specimens obtained by means of bilateral ureteronephrectomy. We also established the cumulative incidence of bladder urothelial carcinoma in biopsies performed during prospective screening cystoscopies during a 15-year follow-up.

RESULTS

Upper-tract urothelial carcinoma was found in 17 patients with aristolochic acid nephropathy (44.7%). During follow-up, bladder urothelial carcinoma was diagnosed in 15 patients 68 to 169 months after cessation of aristolochic acid exposure (39.5%): 8 urothelial carcinoma in situ, 4 noninvasive low-grade papillary urothelial carcinoma, and 3 infiltrating urothelial carcinoma. 12 of 17 patients (71%) with a history of upper-tract urothelial carcinoma developed bladder urothelial carcinoma during follow-up, whereas this occurred in only 3 of 21 patients (14%) without upper-tract urothelial carcinoma (P < 0.01). Despite local and/or systemic chemotherapy, 3 patients died and 2 radical cystectomies were performed.

LIMITATIONS

Small sample size of this case series.

CONCLUSIONS

Upper-tract and bladder urothelial carcinoma are dramatic complications in kidney transplant recipients with aristolochic acid nephropathy, confirming the carcinogenic properties of aristolochic acids. We identified upper-tract urothelial carcinoma as a potent risk factor for the subsequent development of bladder urothelial carcinoma after kidney transplantation for aristolochic acid nephropathy. Because this complication may occur years after aristolochic acid discontinuation, we suggest regular cystoscopies in addition to the bilateral ureteronephrectomy in kidney transplant recipients with aristolochic acid nephropathy.

Efficacy of a liver resection for hepatocellular carcinoma in patients with chronic renal failure

PURPOSE

As there is still little information available on hepatic resection in patients with chronic renal failure (CRF) in the literature, it is believed that a liver resection for HCC in CRF patients with various related complications is always risky.

METHODS

We retrospectively reviewed the clinical and pathological records of 17 patients with CRF who had undergone hepatectomy for HCC, and of 51 non-CRF patients subjected to hepatectomy for HCC during the same period.

RESULTS

The operative and pathological findings were comparable between the two groups. Postoperative circulatory insufficiency occurred more frequently in the CRF group (P = 0.013). Although the disease-free survival rates were comparable between the two groups, the overall survival rates were significantly lower in the CRF group than in the non-CRF group (P = 0.031).

CONCLUSIONS

A hepatectomy for HCC should be considered even for CRF patients with various complications if careful perioperative management and suitable multidisciplinary treatment for recurrent disease are provided.

Are so-called uremic toxins always toxic?

OBJECTIVE

Numerous substances qualify as uremic toxins by fulfilling all properties characterizing such compounds. However, their role in the development of uremic state maybe ambiguous. We followed these properties on the example of N-methyl-2-pyridone-5-carboxamide (Met2PY) from the nicotinamide end-products family. The aim of this study was to determine if these uremic compounds are toxic in all circumstances.

METHODS

To establish a direct toxic effect, a cytotoxicity test was performed. The influence of Met2PY on DNA damage in cultured cells was measured, using a comet assay. For in vitro experiments, Moly (L5178Y), LLCPK-1, and A549 cell lines were used. We used 250 microM H2O2 and 200 ng/mL angiotensin II (ANGII) as damaging factors.

RESULTS

A direct cytotoxic effect of Met2PY on Moly cells was observed. In LLC-PK1 cells, co-incubation with 0.03 mM Met2PY protected cells against the DNA damage caused by ANG II. In A549 cells, the action of Met2PY was ambiguous. At lower concentrations (1 and 3 mM), it showed protective effects, although 10 mM Met2PY increased the toxic effect of 250 microM H2O2.

CONCLUSIONS

Our results suggest that Met2PY is not always toxic or harmful. In some circumstances, it may even express beneficial and protective properties.

Nicotinamide metabolites accumulate in the tissues of uremic rats

OBJECTIVE

N-methyl-2-pyridone-5-carboxamide (Met2PY) and N-methyl-4-pyridone-3-carboxamide (Met4PY) are nicotinamide (NA) metabolites described by our group and considered to be uremic toxins. Plasma concentration of Met2PY and Met4PY in end-stage renal disease (ESRD) is several-fold higher in comparison with healthy controls. However, there are no data about the concentrations of these compounds in different tissues. The aim of this study was to establish whether the observed high concentrations of these compounds were also present in different tissues of uremic animals.

METHODS

This study was conducted in 10 5/6 nephrectomized male Wistar rats and 10 sham-operated animals. Concentrations of nicotinamide and its end products were measured using high-performance liquid chromatography and mass spectrometry.

RESULTS

We observed significant elevations of Met2PY and Met4PY in tissues of uremic rats. The greatest differences between healthy and uremic rats were observed in the liver, lungs, and skeletal muscles. Accumulation in the kidney and heart was not so pronounced, but in the case of Met4PY was statistically significant.

CONCLUSIONS

We found that Met2PY and Met4PY accumulate not only in the blood but also in tissues of uremic rats.

Preventive health care in chronic kidney disease and end-stage renal disease

The complex care that must be provided for patients with renal disease might interfere with provision of basic preventive measures in this population. Preventive health care, including infection screening and prophylaxis, vaccinations, management of blood glucose and lipid levels, and cancer screening, is important, as it might decrease acute morbidity and mortality. This Review highlights useful preventive and health maintenance strategies for patients with chronic kidney disease and those with end-stage renal disease.

Patterns in the prevalence of hepatitis C virus infection at the start of hemodialysis in Japan

BACKGROUND

Although hepatitis C virus (HCV) infection is a persistent public health concern in hemodialysis patients, there seem to have been only a few reports on the prevalence of HCV at the start of hemodialysis. In this study we investigated whether patients starting on hemodialysis therapy are positive for anti-HCV antibody or not.

METHODS

The 400 patients who began regular hemodialysis between February 2003 and June 2007 were enrolled in this study. Clinical data such as age, anti-HCV antibody and primary cause of end-stage kidney disease (ESKD) were examined. As healthy controls we used 70,717 healthy blood donors in 2005 whose data were obtained from Tokyo Metropolitan Red Cross Blood Center. Anti-HCV antibody was used as an indicator of HCV infection. Since the prevalence of HCV infection is affected by age in Japan, we classified the patients by age group.

RESULTS

The anti-HCV antibody prevalence rate among the patients who were new to hemodialysis was 7.3%, as opposed to 0.15% in the healthy volunteers. The prevalence of HCV in the 31-45-, 46-60-, and 61-year-old groups was significantly higher among the hemodialysis patients than among the healthy volunteers (P = 0.0209, <0.0001, and <0.0001, respectively). The prevalence rate of anti-HCV antibody was higher among men (10.0%) than among women (1.5%, P < 0.0001) in the hemodialysis patients. The anti-HCV-antibody-positive patients were significantly older than the anti-HCV-antibody-negative patients (66.4 +/- 14.3 years versus 58.6+/-16.6 years; P = 0.0152). Diabetic nephropathy was a more frequent cause of ESKD among the anti-HCV-antibody-positive patients (30.4%) than among the anti-HCV-antibody-negative patients (19.9%, P = 0.0122). Among the anti-HCV-antibody-positive patients, 55.2% had received a blood transfusion. The rate was significantly higher than that among the anti-HCV-antibody-negative patients (19.4%, P < 0.0001).

CONCLUSION

The results showed a much higher rate of anti-HCV antibody positivity in patients new to hemodialysis than in healthy volunteers. Older age, blood transfusion, male gender, and diabetic nephropathy seemed to be risk factors for anti-HCV antibody positivity in Japan.

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.

Clinicopathological characteristics of thyroid cancer in patients on dialysis for end-stage renal disease

BACKGROUND

The prevalence rate of thyroid cancers in patients with renal failure is variable in different studies. Our aim was to determine the prevalence and clinicopathological characteristics of thyroid cancers in the dialysis population and to evaluate the potential risk factors.

METHODS

We performed a retrospective analysis on end-stage renal disease (ESRD) patients on dialysis and thyroidectomized patients without ESRD (2000-2006). Then we compared the data of thyroid cancer patients on dialysis (n = 9) with the data of patients who had histopathologically verified benign thyroid disease on dialysis (n = 23) and with the histopathological data of thyroid cancer patients without ESRD.

RESULTS

Papillary thyroid cancer (PTC) was the only histotype that was found in 9 of 420 (2.1%) ESRD patients on dialysis. Multifocal PTC was found in eight of nine patients; of them, four had follicular variant of PTC (FVPTC). Two patients had lymphatic metastasis at diagnosis. Eight PTCs were classified as tumor-node-metastasis (TNM) stage I and one as stage II. Among the analyzed factors, age (r = 0.374, p = 0.01) and duration of dialysis (r = 0.436, p = 0.007) showed a significant positive correlation with the occurrence of thyroid cancer.

CONCLUSIONS

We conclude that the prevalence of thyroid cancer in patients undergoing dialysis was not higher than that in the background population. Age and duration of dialysis showed a significant positive correlation with the occurrence of thyroid cancer in patients on dialysis. Among the histotypes, there may be higher percentage of PTC, FVPTC, and multifocality in dialysis patients. The effect of these characteristics on prognosis of thyroid cancer in dialysis patients is needed to be further evaluated.

Partial remission of a newly diagnosed diffuse large B-cell Non-Hodgkin's lymphoma in a hemodialysis patient after administration of immuno-chemotherapy with rituximab-CHOP

To date little data exist about treatment of hematologic malignancies in patients with end-stage renal disease (ESRD). While administration of immunochemotherapy comprising the CD20-antibody rituximab is a well-established treatment strategy in patients with normal renal function, little information on safety and efficacy is available in the setting of ESRD. Here we describe for the first time a hemodialysis patient suffering from diffuse large B-cell Non-Hodgkin's lymphoma (DLBCL) who was treated with polychemotherapy (cyclophosphamide, doxorubicin, vincristine and prednisone) in combination with rituximab (R-CHOP). We observed no major adverse events and treatment resulted in a partial remission of the DLBCL. Thus, administration of R-CHOP may be considered as a safe therapeutic option in this setting. Of note, this patient had a previous history of hairy cell leukemia. A review of the literature was performed and the potential etiologic link of these two B-cell malignancies is discussed in the light of available information.

Homocysteine exerts genotoxic and antioxidative effects in vitro

INTRODUCTION

Patients with end-stage renal disease suffer from increased genomic damage and cancer incidence. One possible reason is the accumulation of uremic toxins such as homocysteine (Hcy). Elevated Hcy levels--usually indicative of cardiovascular events--correlated with the genomic damage in cross-sectional studies. Therefore we investigated the genotoxic effects of Hcy in vitro.

METHODS

To analyse the genomic damage, micronucleus tests and the comet-assay were performed in L5178Y and HL60 cells. Additionally, the influence of Hcy on cell cycle progression, DNA-cytosine-methylation, oxidative stress levels and on the cellular glutathione content were determined.

RESULTS

Low millimolar concentrations of Hcy-induced micronuclei in both cell lines but did not enhance the DNA damage observed with the comet-assay. Cell cycle progression was inhibited in S-phase, while DNA-cytosine-methylation remained unchanged. Furthermore, Hcy protected cells challenged with H(2)O(2) from oxidative stress. This was accompanied by an increased cellular glutathione level.

CONCLUSION

Since the genotoxic effect was limited to high Hcy concentrations, a contribution of Hcy to the enhanced genomic damage in end-stage renal disease patients would only be conceivable upon local Hcy accumulation. Whether the detected antioxidant capacity of Hcy is relevant for any situation in patients remains to be elucidated.