A UFLC-MS/MS Method for the Simultaneous Analysis of Urinary Podocin and Podocalyxin in Patients with Nephrotic Syndrome

OBJECTIVE

To create an efficient and robust mass spectrometric method for the simultaneous quantitation of podocin and podocalyxin in urine samples and to evaluate urinary podocin and podocalyxin levels in patients with nephrotic syndrome (NS).

METHODS

A mass spectrometric method was generated for the measurement of tryptic peptides in urine sediment. Separation of peptides was achieved via liquid chromatography, and mass spectrometric analyses were conducted by electrospray ionization triple-quadrupole mass spectrometry in the multiple reaction monitoring mode.

RESULTS

Intra- and interassay precision values were below 12% and accuracies ranged from 87% to 111% for both of peptides. The validated method was successfully applied to detect these peptides in patients with NS. Urine podocin and podocalyxin levels were significantly higher in patients with NS compared to healthy controls.

CONCLUSIONS

This proposed mass spectrometric method provides technological evidence that will benefit the clinical field in the early diagnosis and follow-up of NS.

Serum uromodulin levels, MR imaging findings, and their relationship with eGFR-based CKD staging in ADPKD patients

PURPOSE

Autosomal dominant polycystic kidney disease (ADPKD) is the most common hereditary kidney disease that may progress to end-stage renal disease, characterized by increased kidney volume due to cystic formations. In this study, we aimed to investigate the relationship between serum uromodulin levels, total kidney volume and estimated glomerular filtration rate (eGFR) in patients with ADPKD.

METHODS

This study included a total of 54 ADPKD patients and 18 healthy volunteers (control group). Total kidney volumes were calculated through magnetic resonance images using ellipsoid method. Serum uromodulin measurements were measured using an ELISA method.

RESULTS

Serum uromodulin levels were lower in patients compared with the control group (2.47 ± 0.16 vs 2.6 ± 0.28, p = 0.021). There was no significant difference in uromodulin values among the patients in chronic kidney disease (CKD) stages 1-2, 3 and 4-5. TKV measurements of CKD stage 4-5 patients were significantly higher than the stage 1-2 patients (p = 0.015). A negative correlation was observed between TKV and eGFR (r = - 0.433, p = 0.001). A positive correlation was observed between uromodulin and eGFR (r = 0.274, p = 0.02). When the serum levels of uromodulin and the level of eGFR were evaluated using simple linear regression analysis, R² value was found to be 0.075, suggesting that 7.5% change in serum uromodulin values corresponds with the change in eGFR value.

CONCLUSION

These findings are consistent with previous studies that reported that serum uromodulin may be a good biomarker for demonstrating renal function in the early stages of CKD, before eGFR levels deteriorate. Serum uromodulin level may be useful in demonstrating renal functions in the follow-up of individuals with ADPKD.

A case of cyclic hemoperitoneum in a hemodialysis patient: Encapsulated peritoneal sclerosis complicated by endometriosis and fungal peritonitis

Encapsulated peritoneal sclerosis (EPS) is a rare, but frequently fatal, long-term complication of peritoneal dialysis. Endometriosis is a common gynecological problem but hemoperitoneum due to endometriosis has been reported to be extremely rare in hemodialysis (HD) patients. A 25-year-old female HD patient was admitted to our clinic with nausea, vomiting, abdominal pain, and weight loss for last 3 months. Candida tropicalis and Candida glabrata were isolated in the fungal cultures from peritoneal fluid. Her abdominal computerized tomography scan has shown irregular peritoneal calcifications, diffuse peritoneal thickening, dilatation of the small bowel loops, and cocoon formation which all were typical for EPS. Hemoperitoneum was reported to recur for four times with intervals suggesting menstrual cycles. Her peritoneal biopsy, along with the signs of EPS, has also revealed the presence of endometriosis. The patient died with symptoms of septic shock in the first year of EPS diagnosis.

Effect of prophylactic versus preemptive lamivudine treatment and tenofovir on HBsAg+ kidney transplant recipients

OBJECTIVES

Chronic hepatitis B virus infection remains a clinical problem for HBsAg (+) kidney transplant recipients. Lamivudine is the approved treatment; however, there are contrary views about optimal initiation. In case of resistance, novel nucleoside analogs should be considered but experience is limited.

MATERIALS AND METHODS

The study was a retrospective cohort study that included 58 HBsAg (+) kidney transplant recipients. Medical records were reviewed for nucleoside analogs, viral replication, and graft/hepatic functions. Prophylactic and preemptive lamivudine modalities were compared to reveal optimal initiation. Additionally, novel nucleoside analogs were evaluated for safety and efficacy.

RESULTS

The graft/patient survival rates for HBsAg (+) recipients were the same as those of hepatitis-free recipients (P = .18). Prophylactic group had 24 and the preemptive had 34 patients. In the prophylactic group, there were fewer hepatic dysfunctions (12.5% vs. 30%, P = .12), viral breakthroughs (16% vs. 32%, P = .17) and elevated alanine aminotransferase concentrations (37% vs. 52%, P = .24), however these did not reach statistical significance. Progressive hepatic dysfunction was observed in 5 patients. Treatment was altered to tenofovir (n = 4) and adefovir (n = 1), and adequate virologic/biochemical response was achieved. These nucleoside analogs were almost as safe as lamivudine, as there were no significant differences among proteinuria (4740 ± 9480 vs 1250 ± 430 mg/L; P = .60) and estimated glomerular filtration rate (1.23 ± 0.37 vs 1.10 ± 0.35 mL/s; P = .33) CONCLUSIONS: Lamivudine is an efficient means of providing comparable graft/patient survival with hepatitis-free kidney transplant recipients. The prophylactic initiation of lamivudine may be better in preventing hepatic dysfunction. Tenofovir can be an effective and safe treatment for lamivudine-resistant kidney transplant recipients.

The impact of diabetes mellitus on peritoneal dialysis: the Turkey Multicenter Clinic Study

PURPOSE

It is well established that diabetic peritoneal dialysis (PD) patients have a higher mortality rate than the other PD population. This study was designed to determine the overall predictors of survival and compared mortality and morbidity between diabetic and non-diabetic Turkish PD patients.

METHODS

We conducted a multicenter retrospective study with 915 PD patients [217 had diabetes mellitus (DM)]. Serum albumin, PTH, HbA1c, co-morbid diseases, dialysis adequacy (Kt/V), and peritoneal transport characteristics as well as peritonitis episodes and ultrafiltration failure during the follow-up period were recorded.

RESULTS

DM patients were older and had more co-morbidities than non-DM patients. Peritonitis rates were higher in DM patients (one episode per 35.9 patient months) compared to non-DM patients (one episode per 41.5 patient months) (p < 0.001). On Kaplan-Meier analysis, patient survival was significantly lower in DM patients with the 2-, 3- and 5-year patient survival rates of 90.8%, 87.8% and 78.2% in non-diabetics and 80.9%, 70.4% and 61.2% in diabetics, respectively. On Cox regression analysis, DM (HR 1.5, p = 0.022), age (HR 1.03, p < 0.001), baseline serum albumin (HR 0.39, p < 0.001), heart failure (HR 0.038, p = 0.038), peripheral artery disease (HR 1.83, p = 0.025) and amputation (HR 4.1, p = 0.009) at baseline were significant predictors of overall mortality.

CONCLUSIONS

Patient survival is lower in diabetic compared to non-diabetic patients on PD. Peritonitis rates were also higher in diabetic PD patients. DM, older age, albumin level and cardiovascular co-morbidities are predictors of mortality.

Arm circumference: its importance for dialysis patients in the obesity era

PURPOSE

The purposes of this study were to investigate the association between arm circumference and body mass index (BMI) and to discuss problems, mainly arm circumference and cuff size mismatch, that could affect the reliability of home blood pressure monitoring (HBPM) among peritoneal dialysis (PD) and hemodialysis (HD) patients.

METHODS

525 PD and 502 HD patients from 16 centers were included in the study. A two-part questionnaire was used to gather information from the participants. Arm circumferences were categorized into four groups according to the British Hypertension Society cuff size recommendations.

RESULTS

Mean BMI and arm circumference of all participants were 25.0 kg/m(2) and 27.6 cm, respectively. There was a significant correlation between BMI and arm circumference. The mean BMI and arm circumference values were higher in PD patients than in HD patients. Requirement of a large-sized adult cuff was more common among PD patients compared to HD patients (14 % vs 8 %, p = 0.002).

CONCLUSIONS

Since HBPM is a useful tool for clinicians to improve BP control, nephrologists should be aware of the problems related to HBPM in dialysis patients and take an active role to increase the reliability of HBPM.

The impact of hepatitis C virus infection on long-term outcome in renal transplant patients

BACKGROUND/AIMS

The aim of this study was to determine the effect of hepatitis C virus infection on patient and graft survival and liver function in renal transplant patients.

METHODS

1811 renal transplant patients were included in this study. One hundred renal transplant patients (5.5%) were anti-hepatitis C virus-positive. We evaluated demographic, clinical, biochemical, and serological data of patients and compared patient and graft survivals between hepatitis C virus-positive and -negative renal transplant patients.

RESULTS

The median follow-up period was 35.7 months. One hundred (5.5%) patients were anti-hepatitis C virus-positive. There were no differences between anti-hepatitis C virus-positive and -negative renal transplant patients regarding age, etiology of renal disease, number of pre-transplant blood transfusions, and hepatitis B virus coinfection rate. Rate of graft loss in anti-hepatitis C virus-positive renal transplant patients was significantly higher than in anti-hepatitis C virus-negative patients (16.0% vs. 9.2%, p=0.026). Survival analysis revealed that patient survival was similar between anti-hepatitis C virus-positive and -negative renal transplant patients. Graft survival was lower in the anti-hepatitis C virus-positive group than in anti-hepatitis C virus-negative patients, especially after the fifth year of renal transplant (p<0.001). Thirty-three percent of anti-hepatitis C virus-positive patients were positive for hepatitis C virus RNA. Twenty-seven percent of anti-hepatitis C virus-positive patients had persistent alanine aminotransferase elevation. None of the patients developed cirrhosis during the follow-up period.

CONCLUSION

Our findings suggest that hepatitis C virus infection in renal transplant patients does not adversely affect patient survival. Long-term graft survival seems to be lower in hepatitis C virus-positive compared to hepatitis C virus-negative renal transplant patients. Nevertheless, renal transplant can be considered as a safe and effective treatment modality in anti-hepatitis C virus-positive patients with end-stage renal disease.

Effects of Different Dialysis Modalities on Cardiac Autonomic Dysfunctions in End‐Stage Renal Disease Patients: One Year Prospective Study

Cardiac autonomic dysfunction (CAD) is a common problem in patients with end-stage renal disease (ESRD) and may contribute to the risk of cardiac mortality. Long-term effects of dialysis modalities on CAD in ESRD patients are not clear. In this one-year prospective study, we studied the effects of different dialysis modalities on CAD in ESRD patients. The study consisted of 20 ESRD patients who had the indications for initiating dialysis therapy (13 hemodialysis and 7 CAPD patients) and 15 healthy controls (M/F: 5/10; age 30 +/- 4). In all the subjects, first at the beginning of study (in patient groups just before initiating dialysis therapy) and then after 12 months, we studied 24 hours ECG-Holter monitoring and heart rate variability parameters (time and frequency domain analysis parameters; SDNN: standard deviations of nn intervals, rMSSD: square root of the median of standard deviation, HRVI: heart rate variability index, LF/HF: low frequency/high frequency). In ESRD patients, before dialysis therapy, all the parameters of time domain analysis were significantly lower compared to control group (p = 0.001). In patient groups, after dialysis therapy (on the 12th month), significant improvement was observed in time domain analysis parameters (p = 0.001). When dialysis modalities were compared, the increase in the time domain analysis parameters was significantly greater in the CAPD group compared to hemodialysis (HD) group. Our findings suggest that CAD is frequent in ESRD patients, a dialysis therapy of 12 months can cause significant improvement on CAD and the ameliorative effect of CAPD is better than HD.

Oxidative stress and asymmetric dimethylarginine is independently associated with carotid intima media thickness in peritoneal dialysis patients

BACKGROUND

Oxidative stress (OS) and asymmetric dimethylarginine (ADMA) are accepted as nonclassical cardiovascular risk factors in end-stage renal disease patients. To clarify the role of these factors in the atherosclerotic process, we investigated if OS and ADMA are associated with common carotid artery intima media thickness (CIMT) in peritoneal dialysis (PD) patients.

METHODS

Thirty PD patients without known atherosclerotic disease and classical cardiovascular risk factors as well as age- and gender-matched 30 healthy individuals were included. We measured serum thiobarbituric acid-reactive substances (TBARS), malondialdehyde (MDA), advanced glycation end product (AGE), pentosidine, advanced oxidation protein products (AOPP), ADMA and CIMT in each subjects.

RESULTS

TBARS, MDA, AOPP, AGE, pentosidine and ADMA levels were significantly higher in PD patients than in controls (p < 0.001). CIMT in patients was higher than in the control group (0.83 +/- 0.09 vs. 0.77 +/- 0.06 mm; p < 0.01). CIMT was independently correlated with TBARS (beta = 0.33, p < 0.01), MDA (beta = 0.27, p < 0.01), AOPP (beta = 0.22, p < 0.02), AGE (beta = 0.45, p < 0.01), pentosidine (beta = 0.56, p < 0.01) and ADMA (beta = 0.54, p < 0.01).

CONCLUSIONS

OS markers and serum ADMA levels independently predict the CIMT level in PD patients.

Mutations of chronic granulomatous disease in Turkish families

BACKGROUND

Chronic granulomatous disease (CGD) is an inherited disorder of the innate immune system characterized by impairment of intracellular microbicidal activity of phagocytes. Mutations in one of four known NADPH-oxidase components preclude generation of superoxide and related antimicrobial oxidants, leading to the phenotype of CGD. Defects in gp91-phox, encoded by CYBB, lead to X-linked CGD and have been reported to be responsible for approximately 70% of all CGD cases. The aim of this study was to identify the CGD mutations in a group of Turkish CGD patients and to evaluate the predominance of CGD mutations as X-linked or autosomal recessive (AR) within the Turkish CGD families with known mutations.

MATERIALS AND METHODS

Two Turkish CGD families were included in the study, and mutations were identified by sequence analysis of DNA and RNA from peripheral blood in the patients. Before mutation analysis, subgroup analysis of patients was made by flow cytometry with antibodies against NADPH oxidase components and with DHR-123 oxidase activity assay. For comparison, we included previously reported results from four other Turkish CGD families.

RESULTS

Two different mutations were identified, one of them a novel mutation g.700G>T located in exon 7 of CYBB, and the other a hot-spot mutation located in exon 2 of the NCF1 gene. These mutations were detected in three patients from two Turkish families.

CONCLUSIONS

Until now, we have altogether identified mutations in six Turkish CGD families. In this limited number of families our results show AR-CGD in two-thirds of the Turkish families investigated, in contrast to previous reports in the literature. This is probably due to the high rate of consanguineous marriages in Turkey. Consanguineous parents were found in 75% of the families with AR-CGD patients, which favours homozygous deficiencies.

Hemophagocytic syndrome in kidney transplant recipients: report of four cases from a single center

BACKGROUND

The prognosis of hemophagocytic syndrome (HPS) in kidney transplant recipients is reported to be poor, however the optimal therapeutic approach is still unclear.

PATIENTS AND METHODS

The clinical and follow-up data of the 4 patients with HPS (3 male, 1 female; age 39.7 +/- 11.3 years) among 368 kidney transplant recipients during a 5-year period were retrospectively analyzed.

RESULTS

HPS developed 35-61 days in the post-transplant period. All 4 patients presented with fever. Hepatosplenomegaly and lymphadenopathy were observed only in the first patient. Laboratory tests revealed pancytopenia and hyperferritinemia in all patients, but elevated liver enzymes were observed in 3. Two patients had cytomegalovirus infection, and 1 had Epstein-Barr virus infection. Three patients died despite aggressive supportive therapy, however the fourth case survived after graft nephrectomy.

CONCLUSION

HPS pathogenesis in kidney transplants appears to be related with the graft itself. Graft nephrectomy may be the preferable therapeutic approach for kidney transplant recipients with HPS resistant to standard supportive therapy.

Assessment and comparison of endothelial function between dialysis and kidney transplant patients

Dialysis and kidney transplant patients display endothelial dysfunction. Previous studies concerning comparisons of endothelial function in dialysis and kidney transplant patients included subjects with cardiovascular risk factor(s) that alone may lead to endothelial dysfunction. In this study, we compared endothelial function between dialysis and transplant patients who did not show known cardiovascular risk factors that lead to endothelial dysfunction. We studied age- and gender-matched cohorts: 30 hemodialysis (HD), 30 peritoneal dialysis (PD), and 30 kidney transplant patients. We also included 20 age- and gender-matched healthy controls. We assessed the endothelial function of patients and controls by a noninvasive technique. Serum biochemistry profiles of patients were also similar to controls in terms of lipid profile and fasting blood glucose level. Although mean FMD% levels of HD and PD patients were similar (6.6% +/- 3.1% vs 6.8% +/- 3.0%, P > .05), the mean percent of flow-mediated endothelium-dependent dilatation (FMD%) level in transplant patients was higher than those in HD or PD patients (10.50% +/- 3.0% vs 6.6% +/- 3.1% and 6.8% +/- 3.0%, respectively; P < .01). In addition, the mean FMD% level in healthy controls was higher than those in HD, PD, and transplant patients (14.0% +/- 2.3% vs 6.6% +/- 3.1%, 6.8% +/- 3.0% and 10.50% +/- 3.0%; P < .01, respectively). In conclusion, endothelial functions in transplant patients were better than those in dialysis patients.

Skewing of X-chromosome inactivation in three generations of carriers with X-linked chronic granulomatous disease within one family

BACKGROUND

Chronic granulomatous disease (CGD) is an inherited disorder of the innate immune system characterized by impairment of intracellular microbicidal activity of phagocytes. Mutations in one of the four known NADPH-oxidase components preclude generation of superoxide and related antimicrobial oxidants, leading to the phenotype of CGD. Defects in gp91-phox, encoded by CYBB, lead to X-linked CGD, responsible for approximately 70% of all CGD cases. The aim of the study was to evaluate the hypothesis that age-related skewing of X-chromosome inactivation, as described in several CGD families, is caused by preferential survival of bone marrow clones with an inactive NADPH oxidase.

MATERIALS AND METHODS

We studied the neutrophils from three patients and four carriers in three generations of a Turkish family with X-linked CGD. Carrier detection was carried out by the dihydrorhodamine (DHR)-1,2,3 assay, which measures on a per-cell basis the NADPH oxidase-dependent oxidation of DHR by phagocytes. The X-chromosome inactivation pattern was determined with the HUMARA assay in DNA from leucocytes as well as in DNA from a buccal smear of the four carriers.

RESULTS

The three patients were identified by a negative DHR test, and the mutation in their CYBB gene was characterized by DNA sequencing. Moreover, we found an age-related degree of skewing of X-chromosome inactivation in the leucocytes of the four X-CGD carriers, both at the protein level (NADPH oxidase activity) and at the DNA level (HUMARA assay). However, similar skewing of X-chromosome inactivation was found in the buccal DNA from these women.

CONCLUSIONS

These novel findings indicate that the age-related degree of skewing was probably a chance finding, not related to preferential survival of NADPH oxidase-deficient precursor cells, because this enzyme is not expressed in (buccal) epithelial cells.

Effect of renal transplantation on endothelial function in haemodialysis patients

BACKGROUND

Haemodialysis patients (HD) have been characterized by a high incidence and prevalence of atherosclerotic cardiovascular disease. Based on the traditional cardiovascular risk factors in this population, we cannot explain this high incidence and prevalence. One of the mechanisms contributing to cardiovascular risk in HD patients may be to uraemic toxins. Cardiovascular risk factors and uraemic toxins themselves may cause endothelial dysfunction, which may play a pivotal role in the development and progression of atherosclerosis in this population. We hypothesized that elimination of uraemic toxins in response to renal transplantation (RTx) can improve endothelial function as assessed by flow-mediated dilatation of brachial artery in haemodialysis (HD) patients.

METHODS

Endothelial function measured by flow-mediated dilatation of the brachial artery (FMD) and glyceryltrinitrate-induced dilatation of the brachial artery (NMD) were assessed twice, during haemodialysis treatment and after RTx in 30 chronic haemodialysis patients. All patients were characterized by absence of known atherosclerotic disease and traditional cardiovascular risk factors. We also studied age- and gender-matched 20 normotensive healthy controls.

RESULTS

FMD values significantly improved after RTx (6.69+/-3.1% vs 10.50+/-3.0%, P<0.001) in HD patients. FMD of patients both during haemodialysis and after RTx was lower than in healthy controls (6.69+/-3.1%, 10.50+/-3.0% vs 14.02+/-2.3%, P<0.001 and P<0.01, respectively). There was no change in NMD values after RTx in HD patients (16.27+/-1.9% vs 16.30+/-1.8%, P>0.05). Also, NMD values in all patients were similar to healthy control values.

CONCLUSIONS

There is an improvement of endothelial function as assessed by FMD of the brachial artery after RTx in HD patients. This may be attributed to the elimination of uraemic toxins by successful RTx.

How accurate is measuring postvoid residual volume by portable abdominal ultrasound equipment in peritoneal dialysis patient?

INTRODUCTION

Despite the wide spread use of modern portable ultrasound equipment to measure the postvoid residual urine, its accuracy and reliability has been questioned. We investigated the accuracy of postvoid residual urine measurement by portable abdominal ultrasound equipment in end-stage renal disease patients who are under either hemodialysis or peritoneal dialysis.

MATERIALS AND METHODS

A total of 21 male (range: 25-44 years, mean age: 32 years) end-stage renal disease patients were studied. Ten were under peritoneal dialysis and 11 under hemodialysis. After uroflowmetric study, all patients were evaluated with portable abdominal ultrasound equipment (BladderScan BVI 3000, Diagnostic Ultrasound Corporation, WA) by both a technician and a physician and they were subsequently catheterized with a 10F catheter to measure the residual urine volume in the urinary bladder. Postvoid residual urine volume results by portable abdominal ultrasound equipment and urethral catheterization were analyzed.

RESULTS

We found portable abdominal ultrasound to be very accurate to measure the volume of postvoid residual urine in hemodialysis patients(r=0.921, P<0.05 by physician and r=0.904, P<0.05 by technician). However, accuracy was the worst in peritoneal dialysis patients (r=0.055, P=0.88 by physician and r=0.336, P=0.343 by technician). The technician or physician use of the equipment did not change the accuracy profile of the equipment in both hemodialysis and peritoneal dialysis patients.

CONCLUSIONS

Portable abdominal ultrasound equipment may be an unreliable method to measure postvoid residual urine volume in peritoneal dialysis patients.

Influence of tacrolimus plus mycophenolate mofetil regimens on acute rejection rate and diabetes mellitus development in renal transplant recipients

In this study we investigated the influence of a tacrolimus (TAC) plus mycophenolate mofetil (MMF) immunosuppressive regimen on the acute rejection rate and side effect profile in renal transplant recipients. The study included 80 living-related and 40 cadaveric donor renal transplant recipients (82 men, 38 women) of mean age 35 +/- 10 years (range, 16 to 58) who were operated between August 1999 and September 2002. The mean HLA mismatches was 3 +/- 1 (range, 0 to 5). All patients received prednisolone, MMF (2 g/d for the first 14 days posttransplant and then 1 g/d) plus TAC (0.2 mg/kg/d). They were followed for the development of rejection attacks and side effects. Diabetes mellitus developed in 13 patients (9 men, 4 women; 10.8%). Initially, patients required insulin therapy but after 6 months, 5 recipients no longer needed insulin therapy and were switched to oral hypoglycermic agents and diet control. Hypertension was diagnosed in 58 patients (48.3%). Neither gender nor donor origin (P =.14; P =.79, respectively) produced a significant difference in diabetes mellitus development. Biopsy proven acute rejection episodes were observed in 16 out of 120 patients (13.3%). Six out of 120 patients lost their grafts throughout the study period including one death because of suicide, one because of cytomegalovirus disease and hemophagocytic syndrome, one due to posttransplant lymphoproliferative disease and two to a cardiac arrhythmia. Only one patient lost his graft due to acute accelerated vascular rejection. Biopsy-proven chronic rejection appeared in one patient. In conclusion, although the incidence of insulin-dependent diabetes mellitus during posttransplant 6 months, seems high it decreased to 1.6% upon reduction of the TAC dosage. TAC plus MMF immunosuppression seems effective and safe in terms of acute rejection rates and side effect profiles.

Cigarette smoking in renal transplant recipients

Cigarette smoking may adversely influence patient and graft survival. In Europe and the United States the prevalence of cigarette smoking in dialysis patients is 35% to 40% and 25%, respectively. In Turkey, the estimated prevalence of cigarette smoking rate in the normal population is 26%. This study evaluated the rate of smoking in 63 cadaveric, and 158 living-related renal transplant recipients including (150 men, and 76 women of 38 +/- 12 years; range, 8 to 70) who were operated between 1986 and 2001. Demographic data were collected with a questionnaire delivered to patients during their routine outpatient visits. During this time period, 8 patients had died, 4 from hemophagocytic syndrome, 2 from cardiovascular disease, 1 from Kaposi sarcoma and 1 from a cerebrovascular accident. Twenty-three patients have lost their grafts. While at the time of transplantation 97 (42%) were smoking cigarettes, only 29 (12%) continued smoke after transplantation. Male gender significantly correlated with cigarette smoking (P =.000). Twelve smokers were single but 85 out of 97 were married, a statistically significant difference (P =.010). In contrast there was no significant relationship between pretransplant smoking and educational status (P =.354); graft loss and smoking (P =.129); or mortality and smoking (P =.224). There was a significant relationship between pretransplant and posttransplant smoking (P =.000). There was no relationship between pre- and post-transplant smoking and development of diabetes mellitus or hypertension. Interestingly the posttransplant serum albumin level was lower among smokers than nonsmokers (4.44 +/- 0.02 g/dL vs 4.30 +/- 0.02 g/dL; P =.019). There was a close relationship between transplantation duration and smoking.

The value of low-dose intraperitoneal immunoglobulin administration in the treatment of peritoneal dialysis-related peritonitis

BACKGROUND

Peritonitis is a major complication of continuous ambulatory peritoneal dialysis (CAPD). The value of immunomodulatory therapeutic approaches and, especially, methods aimed at augmenting opsonization in the treatment of peritoneal dialysis (PD)-related peritonitis is unclear. In this study, the effect of intraperitoneal (IP) immunoglobulin (Ig) usage, as an approach for strengthening opsonization, was evaluated in CAPD peritonitis.

METHODS

The study included 24 patients with CAPD peritonitis. The patients were divided into two groups, A and B, each consisting of 12 patients. There were no significant differences between the groups in terms of age, gender, CAPD duration, and peritonitis rate. Empiric antibiotic treatment was a 2-week IP ampicillin+sulbactam/netilmycin combination. Group B was additionally given low-dose IP IgG (2 mL = 320 mg) with every exchange. The dialysate leucocyte counts were obtained in both groups until the number was <100 cells/microL to monitor the response to peritonitis treatment.

RESULTS

In group A, the number of exchanges done until the dialysate leucocyte counts decreased to <100/mL was 13.9 +/- 1.4 and for group B 6.6 +/- 0.4 (p<0.001). The reduction in neutrophils was significantly faster in group B compared to group A (p<0.001). The number of exchanges until abdominal pain completely disappeared was 12.5 +/- 1.7 in group A and 5.6 +/- 0.7 in group B (p<0.001).

CONCLUSIONS

The results of this study show that low-dose, continuous IP IgG administration in the treatment of PD-related peritonitis is safe and effective in shortening the treatment time.

The prevalence and clinical features of tuberculous peritonitis in CAPD patients in Turkey, report of ten cases from multi-centers

OBJECTIVE

To determine the rate, risk factors and outcome of Tuberculous Peritonitis (TBP) in patients treated with continuous ambulatory peritoneal dialysis (CAPD) in our units.

DESIGN

Retrospectively, we reviewed the medical data of all CAPD patients from 12 centers for TBP, covering the period between 1986 and December 2002.

SETTING

All patients were from 12 renal clinics at tertiary-care university hospitals.

RESULTS

Ten cases of TBP were identified among the CAPD patients in our centers. There were five male and five female patients with a mean age of 37.2 years. None of the patients had tuberculosis history, 6 patients had predominance of PNL. One patient had coincidental bacterial peritonitis. Two patients were successfully treated without the removal of the Tenckhoff catheter.

CONCLUSION

TBP in CAPD patients is a very rare complication. In contrast to predominance of lymphocytes in nonuremic patients with tuberculous peritonitis, CAPD patients with tuberculous peritonitis may have predominance of PNL on examination of the peritoneal fluid. Since TBP has high morbidity and mortality, early diagnosis and treatment of disease are extremely important for improving outcome.

Influence of inflammation on the relation between markers of iron deficiency in renal replacement therapy

Iron deficiency is an important factor in the management of anemia in both dialysis and transplant patients. Serum ferritin and transferrin saturation (TS) may be influenced by the presence of inflammation. Recently, the soluble transferrin receptor (s-TfR) has been considered to be a marker of functional iron stores. In this study, parameters of the iron state were investigated in terms of agreement (assessed by kappa) with the diagnosis of iron deficiency and with inflammation. The study was performed in 38 hemodialysis, 31 continuous ambulatory peritoneal dialysis, and 21 anemic renal transplant patients. CRP and amyloid A protein (AAP) were studied as markers of inflammation. Iron deficiency was defined as ferritin <100 mg/L, TS <20%, or s-TfR >1.76 mg/mL. We observed that s-TfR levels were significantly related to both dialysis duration (r = 0.28 in dialysis and r = 0.60 in transplant patients, both P <.05) and PTH levels (r = 0.23 in dialysis and r = 0.55 in transplant patients, both P <.05). Among the transplant group, ferritin and TS, as well as TS and s-TfR were significantly related (r = 0.84 and r = -0.64, respectively), but not s-TfR and ferritin. Among the dialysis group, ferritin and TS, and also TS and s-TfR, were significantly related (r = 0.35 and r = -0.30, respectively), whereas s-TfR and ferritin were not. In the transplant group, the kappa value for agreement between ferritin and TS in the diagnosis of iron deficiency was 0.76 (P =.006), and 0.33 (P =.04), respectively. Among patients with CRP levels <0.3 mg/L or AAP levels <6.4 mg/L, the relation between parameters of iron state was more robust. The kappa value for agreement between ferritin and s-TfR was 0.49 (P =.006) in the dialysis group and 1 (P =.002) for that between ferritin and TS in the transplant group. Our results suggest that PTH levels may influence s-TfR levels. Discordance between ferritin, TS, and s-TfR as markers of iron deficiency might be explained by the effects of inflammation.

Serum cystatin C as an index of renal function in kidney transplant patients

Management of renal transplant patients requires periodic measurement of renal function, which is usually assessed by measuring the glomerular filtration rate (GFR). The most commonly used marker for GFR is serum creatinine, although muscle wasting and tubular secretion may lead to overestimation of the actual GFR. Serum concentrations of the low-molecular-weight proteins, cystatin C and beta(2)-microglobulin (B(2)M), may afford useful markers to determine a reduced GFR. We investigated whether these molecules provide reliable indicators of renal function in 75 renal transplant patients. Cystatin C and B(2)M correlated significantly with creatinine (r =.648, P <.05 and r =.578, P <.05, respectively). Inverse serum creatinine was superior to inverse cystatin C and inverse B(2)M when renal function equations were used (r =.95, P <.05, according to MDRD; r =.87, P <.05, according to Cockroft-Gault). Receiver operating characteristic (ROC) analysis was performed to quantitate the accuracy of the different markers to detect reduced GFR using a cutoff value of 70 mL/min. No significant difference between the areas under the ROC curves comparing cystatin C and B(2)M was observed; however, serum creatinine demonstrated a significantly greater value than cystatin C (.981 vs.724, P =.001). We conclude that serum creatinine is a more efficacious marker than serum cystatin C to assess renal function.

Seroprevalence of antibodies to legionella pneumophila in hemodialysis patients

Patients with chronic renal failure are at increased risk for infections because of impaired cellular immunity. This study was designed to determine the prevalence of antibodies to Legionella pneumophila serogroups 1 to 6 and to evaluate the possible risk factors for Legionnaires' disease in hemodialysis patients. Serum samples to be screened for antibodies against L pneumophila and risk factor data were collected from 252 hemodialysis patients. The overall prevalence of L pneumophila antibodies in hemodialysis patients was found to be 5.16% There was no statistically significant difference between L pneumophila seropositivity and potential risk factors. Further studies are needed to determine possible risk factors for Legionnaires' disease in hemodialysis patients.

Evaluation of the new EMIT tacrolimus assay in kidney and liver transplant recipients

Tacrolimus (FK506) is a potent macrolide immunosuppressant used for prevention of organ transplant rejection following transplantation. Monitoring of blood tacrolimus concentrations is essential to assess organ rejection and toxicity, because of the agent's narrow therapeutic range, wide inter- and intraindividual pharmacokinetic variability as well as drug interactions mediated by alteration in cytochrome P450. Several methods have been developed to monitor tacrolimus; immunoassays, bioassays, and HPLC/MS. The purpose of this study was to compare two analytical methods: the well-established MEIA II tacrolimus immunoassay using the IMx analyzer and the new EMIT 2000 tacrolimus immunoassay on the Cobas Integra 400 system. Tacrolimus results obtained using the two methods have been compared on 180 whole blood samples from kidney and liver transplant patients. The analytical sensitivities of both methods were defined as 1.2 ng/mL for EMIT and 1.5 ng/mL for MEIA II. The within-run CVs (n = 15) obtained with four-level controls were 9.08%, 9.41%, 5.23% and 4.4% for EMIT 2000. The comparison showed the following relationship between two methods: MEIA = 1.08.EMIT + 0.20 (r =.893). In conclusion, the EMIT 2000 tacrolimus immunoassay is a reliable alternative for the MEIA II method to monitor tacrolimus in organ transplant recipients. It provides a valid quantitative measurement of tacrolimus with comparable % CVs in quality-control as well as patient blood samples. Additionally, the EMIT 2000 method provides a rapid analysis of a large number of samples in one run with a low turnaround time and possibilities to reanalyze critical samples.

Plasma homocysteine levels in renal transplant patients on tacrolimus therapy

Increased plasma total homocysteine levels afford an independent risk factor to assess cardiovascular morbidity in patients with normal and impaired renal function, including stable transplant recipients. The purpose of this study was to evaluate plasma homocysteine levels and factors known to influence homocysteine metabolism (folate and Vitamin B(12)) in renal transplanted patients treated with tacrolimus. Plasma homocysteine, serum folate and serum vitamin B(12) concentrations were measured in 18 cadaveric renal transplant patients with stable function both before and 3 months after the renal transplantation. While the mean plasma homocysteine level in the renal transplant group was significantly higher than in the control group, no significant change was observed following renal transplantation under tacrolimus therapy (16.84 +/- 6.43 micromol/L vs 16.02 +/- 6.54 micromol/L). The levels of folate before and after transplantation were considerably lower than the control group; a significant effect of tacrolimus has not been observed (7.32 +/- 4.68 ng/mL and 7.55 +/- 5.20 ng/mL). Serum vitamin B(12) levels in the transplant group were significantly lower than the control group; a significant decline was seen 3 months after the renal transplantation (448.94 +/- 230.03 pg/mL vs 334.38 +/- 240.61 pg/mL). Consequently, although plasma homocysteine levels of renal transplant recipients are higher, a lowering effect of tacrolimus therapy was not observed on plasma homocysteine levels. The lower levels of folate and Vitamin B(12) in the transplant group compared to a control group supports therapy with folate and Vitamin B(12) to decrease homocysteine concentrations.

Serum levels of prostate-specific antigen and vitamin D in peritoneal dialysis patients

Measuring the free:total ratio of prostate-specific antigen (f/t-PSA) can improve the specificity of single-serum PSA values, distinguishing between benign prostatic hyperplasia (BPH) and prostatic carcinoma (PCa) in men over the age of 50. Additionally, clinical trials have shown that dihydroxyvitamin D3 can slow the rate of PSA rise in PCa patients. However, little is known regarding the applicability of those findings in men undergoing chronic peritoneal dialysis (CPD). In the present study, we investigated the prevalence of increased serum PSA levels among CPD patients and correlated those values with serum levels of vitamin D [25-hydroxyvitamin D3 and 1,25-dihydroxyvitamin D3]. We undertook a cross-sectional study of 71 male CPD patients without a known history of prostate cancer from 24 centers in Canada, Greece, and Turkey. All of the patients were more than 50 years of age. In these patients, we measured serum concentrations of PSA, free PSA (f-PSA), total PSA (t-PSA), prostate alkaline phosphatase (PAP), 25-hydroxyvitamin D3, 1,25-dihydroxyvitamin D3, and intact parathyroid hormone (iPTH). We recorded serum PSA levels < 4 ng/mL in 62 patients (87.3%, group A) and levels > 4 ng/mL in 9 patients (12.7%, group B). The f/t-PSA ratio was < 0.25 in 16 patients (22.5%). Group B patients were older than those in group A (median: 73 years vs. 65 years, p < 0.01) and had a lower body weight (median: 66.5 kg vs. 76.7 kg, p < 0.05). We observed no statistically significant difference between the two groups for serum 1,25-dihydroxyvitamin D3 (median: 9.8 ng/mL vs. 10.1 ng/mL) or 25-hydroxyvitamin D3 (8 ng/mL vs. 8.2 ng/mL) levels. Also, we observed no correlation between vitamin D levels and f/t-PSA, but iPTH levels were significantly higher in group A (200.5 pg/mL vs. 61.2 pg/mL, p < 0.04). Also, serum PAP levels correlated significantly with PSA (r = 0.49, p = 0.01) and with f-PSA (r = 0.56, p = 0.000). Our results showed no clear relationship between vitamin D and serum levels of PSA or-of f/t-PSA in PD patients. However, further studies are needed to better define the uses of these PSA markers in PD patients because, in such patients, other relevant factors might be implicated in their predictive value.

Is there any effect of compliance on clinical parameters of renal transplant recipients?

Noncompliance with regard to diet, medications and routine physician visits is frequently observed among some patient groups. This results in late graft dysfunction and behavior loss. In the present study, we defined compliance as attendance at 80% or more outpatient visits. The study included 63 cadaveric and 158 living-related renal transplant recipients namely, 150 men and 76 women of 8 to 70 years of age (median 38 +/- 12) who were operated between 1986 and 2001. Demographic data, number of visits attended per month, cigarette smoking, and alcohol intake were probed with a questionnaire that was delivered to the patients, 8 of whom died; hemophagocytic syndrome (n = 4), cardiovascular disease (n = 2), Kaposi' sarcoma (n = 1), and cerebrovascular bleeding (n = 1). Twenty-three patients had lost their graft. Compliance among men was lower than among women, a result that trended toward statistical significance (P =.087). Compliance was not related to marital status (P =.297), but tended to increase with educational background (P =.059). Graft loss (P =.546) and aging (P =.509) were not related to compliance. There was no relationship between compliance and mortality rate (P =.526). Interestingly, living-related kidney transplant recipients showed lower compliance than cadaveric kidney recipients, a result that was statistically significant (P =.04). Noncompliance was also related to cigarette smoking during the pre- and posttransplant periods (P =.008 and P =.03, respectively), as well as alcohol intake (P =.000). In conclusion, male gender and living-related donation are related to noncompliance, but (in contrast with literature) not young age, graft loss, or mortality. Compliance increases with educational status of the patients. Smoking and alcohol intake are closely related to noncompliance.

Laparoscopic omental fixation technique versus open surgical placement of peritoneal dialysis catheters

BACKGROUND

Continuous ambulatory peritoneal dialysis (CAPD) is an effective form of treatment for patients with end-stage renal disease. Open insertion of peritoneal dialysis (PD) catheters is the standard surgical technique, but it is associated with a relatively high incidence of catheter outflow obstruction and dialysis leak. Omental wrapping is the most common cause of mechanical problems. The purpose of this study was to determine the efficacy of the laparoscopic omental fixation technique to prevent the obstruction caused by omental wrapping and also to compare this laparoscopic technique with open peritoneal dialysis catheter insertion with respect to postoperative discomfort, complication rates, and catheter survival.

METHODS

Between March 1998 and October 2001, 42 double-cuff, curled-end CAPD catheters were placed in 42 patients. The outcomes of the 21 patients in whom the PD catheters were placed laparoscopically with omental fixation technique were compared with those of the 21 patients in whom the catheters were placed with open surgical technique. Recorded data included patient demographics, catheter implantation method, early and late complications, catheter survival, and catheter outcome.

RESULTS

Early peritonitis episodes occurred in 8 of 21 patients (38.0%) in the open surgical group (OSG) versus 2 of 21 patients (9.5%) in the laparoscopic omental fixation group (LOFG) ( p < 0.05); late peritonitis episodes occurred in 3 of 21 patients (14.2%) in the OSG versus 1 of 21 patients (4.7%) in the LOFG ( p < 0.05). Early exit site infection occurred in 8 of 21 patients (38.0%) in the OSG versus 4 of 21 patients (19.0%) in the LOFG ( p < 0.05), with many catheter-related problems in the conventional surgical group. There was no outflow obstruction in the LOFG. The conventional procedure was faster than the laparoscopic omental fixation technique. Analgesic requirements and hospital stay were less in the laparoscopic group. Laparoscopic surgery also enabled diagnosis of intraabdominal pathologies and treatment of the accompanying surgical problems during the same operation. Occult inguinal hernia was diagnosed in 2 patients, inguinal hernioplasty was performed in 4 patients, adhesiolysis was performed in 8 patients who had previous abdominal surgery, and liver biopsy was taken in 2 patients. Ovarian cystectomy was performed in another patient during laparoscopic CAPD catheter placement.

CONCLUSION

The laparoscopic omental fixation technique (described by Oğünç and published in 1999) is a highly effective and successful method for preventing obstruction due to omental wrapping with a better catheter survival. Laparoscopic surgery also allows the diagnosis and treatment of the accompanying surgical pathologies during the same operation.

The potential role of advanced glycation end product and iNOS in chronic renal failure-related testicular dysfunction. An experimental study

OBJECTIVES

To investigate the impact of advanced glycation end products (AGEs) and inducible nitric oxide synthase (iNOS) in chronic renal failure (CRF)-associated testicular dysfunction in an experimental model. In additionally, we examined whether different peritoneal dialysis (PD) fluids could contribute to the elevation in AGE level and iNOS expression in the testes.

METHODS

Adult male Wistar rats, 10 and 12 weeks of age and weighing 200-330 g, were divided into 5 groups. Group 1 served as the control group. In group 2, CRF was induced and a peritoneal catheter was implanted, but the dialysis procedure was not performed until the end of the study. In group 3, CRF was induced and PD was performed with dialysis fluids containing 1.36% glucose and icodextrin. In group 4, CRF rats received dialysis fluids containing 3.86% glucose and icodextrin. Finally, an indwelling catheter was implanted and the dialysis procedure was performed using dialysis fluids containing 3.86% glucose and icodextrin (group 5). Chronic PD began 4 weeks after insertion of the catheter. Each morning, this fluid was drained and 20 ml dialysis fluid, containing either 1.36 or 3.86% glucose, was given intraperitoneally for 4 h in unanesthetized animals. Each evening, 20 ml icodextrin was given for 10 h. The dialysis procedure was performed for 8 weeks. The AGE level was determined from the 5-hydroxymethyl-2-furaldehyde (5-HMF) content of penis samples and iNOS expression was assessed by immunohistochemistry.

RESULTS

The elevation of 5-HMF was significant in the testes from groups 2, 3, 4, and 5 when compared with group 1. Furthermore, the differences between groups 2 and 4, 3 and 4, and 4 and 5 were also significant (p < 0.05). Immunohistochemical analysis revealed the presence of iNOS predominantly in the Leydig cells. While iNOS staining was significantly lower in group 1 than in other groups, there were also significant differences between groups 2 and 3, 2 and 4, 2 and 5, 3 and 5, and 4 and 5 (p < 0.05). Finally, a significant statistical correlation was found between the 5-HMF and iNOS levels (r = 0.698, p = 0.001).

CONCLUSIONS

The present study identifies, for the first time, a potential role of AGE and iNOS in experimental CRF-associated testicular dysfunction. In addition, we found that PD fluids containing glucose contribute to this effect. These results may lead to a better understanding of the pathophysiological pathway in CRF-related testicular dysfunction.

Intravenous single-dose tramadol versus meperidine for pain relief in renal colic

BACKGROUND AND OBJECTIVE

Comparison of the effectiveness of tramadol with meperidine given intravenously to emergency patients with suspected renal colic.

METHODS

A double-blind, randomized clinical trial was performed in the Emergency Department of a tertiary-care university hospital. Consecutive patients with suspected renal colic (n = 47) were randomized to receive intravenously an initial dose of tramadol 50 mg (n = 23) or meperidine 50 mg (n = 24). After 30 min, additional doses of meperidine 50 mg were given intravenously as a rescue medication in an open fashion. Pain relief was assessed using a 10 cm visual analogue scale, the primary outcomes being pain relief at 15 and 30 min after the analgesics. Secondary outcomes were the frequency of rescue meperidine use and the development of side-effects.

RESULTS

Visual analogue scale pain scores after 15 and 30 min decreased in both tramadol and meperidine groups (P < 0.05). However, pain relief was better in the meperidine group at the 15 and 30 min evaluations (P < 0.05). Only 11 patients (48%), initially receiving meperidine, needed more meperidine compared with 16 patients (67%) initially receiving tramadol. Both drugs were well tolerated with no adverse effects occurring in either group.

CONCLUSIONS

Meperidine 50 mg was superior to tramadol 50 mg for acute pain relief in patients with suspected renal colic when given intravenously. Because many patients in both groups received supplemental meperidine and the response to tramadol alone cannot be predicted, clinicians may want to choose higher doses of meperidine alone or other alternative combinations.

Bruton tyrosine kinase gene mutations in Turkish patients with presumed X-linked agammaglobulinemia

X-linked agammglobulinemia (XLA) is a ptototypical humoral immunodeficiency caused by mutations in the gene coding for Bruton tyrosine kinase (BTK). The genetic defect in XLA impairs early B cell development resulting in marked reduction of mature B cells in the blood. Studies from different countries have demonstrated that approximately 90% of males with presumed XLA bear mutations in BTK. In this study, we report for the first time the occurrence of BTK mutations in Turkey. We performed mutational analysis of the BTK gene in 16 Turkish male patients from 13 separate families with presumed XLA based on abnormally low peripheral blood B-cell numbers (lt; 1%), hypogammaglobulinemia, and recurrent bacterial infections. We found that in nine of the 13 families (69%) a Btk mutation caused XLA. Two of the mutations were previously described, but seven novel mutations were identified: two missense (Y39C, G584R), one nonsense (Q343X), and 4 deletions (1800-1821del, 1843-1847del, 1288-1292del, 291del) resulting in frameshift and premature stop codon. By contrast, no mutations in the BTK gene were identified in the other 4 families. A consanguinity in three of these families raises the possibility that mutations in other autosomal genes which affect early B cell development may contribute to their phenotype resembling XLA.

Transient hypogammaglobulinemia of infancy: clinical and immunologic features of 40 new cases

BACKGROUND

Transient hypogammaglobulinemia of infancy (THI) results from a delay in the maturation of immunoglobulin production.

METHODS

The clinical and immunologic data of 40 patients with THI are presented. Clinically, the majority of patients presented with recurrent respiratory infections and otitis media, bronchitis and/or bronchial asthma and recurrent gastroenteritis.

RESULTS

Ten of 40 children had isolated low IgG; isolated low IgA and isolated low IgM were detected in one and three patients, respectively. At initial evaluation, levels of all three immunoglobluins were low in nine patients. Ten patients had diminished IgG and IgA levels, six had diminished IgA and IgM levels and one had low IgG and IgM levels. Two patients were given intravenous immunoglobulin replacement therapy for 1 year. None of the patients has experienced serious infections during their follow-up period.

CONCLUSIONS

Prospective evaluation of patients (age range 5-60 months) revealed that immunoglobulin levels in 33 patients recovered before 36 months of age. Seven patients still had low immunoglobluin levels at 40-57 months of age. Three of these patients had low levels of both IgG and IgA, while two patients had low IgM levels and a further two patients had low IgA levels.

Activation-induced cytidine deaminase (AID) deficiency causes the autosomal recessive form of the Hyper-IgM syndrome (HIGM2)

The activation-induced cytidine deaminase (AID) gene, specifically expressed in germinal center B cells in mice, is a member of the cytidine deaminase family. We herein report mutations in the human counterpart of AID in patients with the autosomal recessive form of hyper-IgM syndrome (HIGM2). Three major abnormalities characterize AID deficiency: (1) the absence of immunoglobulin class switch recombination, (2) the lack of immunoglobulin somatic hypermutations, and (3) lymph node hyperplasia caused by the presence of giant germinal centers. The phenotype observed in HIGM2 patients (and in AID-/- mice) demonstrates the absolute requirement for AID in several crucial steps of B cell terminal differentiation necessary for efficient antibody responses.