Mehmet Usta

Effect of Fluid Management Guided by Bioimpedance Spectroscopy on Cardiovascular Parameters in Hemodialysis Patients: A Randomized Controlled Trial

BACKGROUND Fluid overload is the main determinant of hypertension and left ventricular hypertrophy in hemodialysis patients. However, assessment of fluid overload can be difficult in clinical practice. We investigated whether objective measurement of fluid overload with bioimpedance spectroscopy is helpful in optimizing fluid status. STUDY DESIGN Prospective, randomized, and controlled study. SETTING & PARTICIPANTS 156 hemodialysis patients from 2 centers were randomly assigned to 2 groups. INTERVENTION Dry weight was assessed by routine clinical practice and fluid overload was assessed by bioimpedance spectroscopy in both groups. In the intervention group (n = 78), fluid overload information was provided to treating physicians and used to adjust fluid removal during dialysis. In the control group (n = 78), fluid overload information was not provided to treating physicians and fluid removal during dialysis was adjusted according to usual clinical practice. OUTCOMES The primary outcome was regression of left ventricular mass index during a 1-year follow-up. Improvement in blood pressure and left atrial volume were the main secondary outcomes. Changes in arterial stiffness parameters were additional outcomes. MEASUREMENTS Fluid overload was assessed twice monthly in the intervention group and every 3 months in the control group before the mid- or end-week hemodialysis session. Echocardiography, 48-hour ambulatory blood pressure measurement, and pulse wave analysis were performed at baseline and 12 months. RESULTS Baseline fluid overload parameters in the intervention and control groups were 1.45 ± 1.11 (SD) and 1.44 ± 1.12 L, respectively (P = 0.7). Time-averaged fluid overload values significantly decreased in the intervention group (mean difference, -0.5 ± 0.8 L), but not in the control group (mean difference, 0.1 ± 1.2 L), and the mean difference between groups was -0.5 L (95% CI, -0.8 to -0.2; P = 0.001). Left ventricular mass index regressed from 131 ± 36 to 116 ± 29 g/m(2) (P < 0.001) in the intervention group, but not in the control group (121 ± 35 to 120 ± 30 g/m(2); P = 0.9); mean difference between groups was -10.2 g/m(2) (95% CI, -19.2 to -1.17 g/m(2); P = 0.04). In addition, values for left atrial volume index, blood pressure, and arterial stiffness parameters decreased in the intervention group, but not in the control group. LIMITATIONS Ambulatory blood pressure data were not available for all patients. CONCLUSIONS Assessment of fluid overload with bioimpedance spectroscopy provides better management of fluid status, leading to regression of left ventricular mass index, decrease in blood pressure, and improvement in arterial stiffness.

Angiotensin-II receptor antagonist losartan reduces microalbuminuria in hypertensive renal transplant recipients

In recent years, it has been demonstrated that losartan lowers macroproteinuria in diabetic or non‐diabetic renal transplant recipients (RTx) similar to angiotensin converting enzyme (ACE) inhibitors. Microalbuminuria (MAU) may reflect subclinical hyperfiltration damage of the glomerulus. It could be a marker of kidney dysfunction in renal transplantation. The aim of the study was to assess the efficacy of losartan in hypertensive RTx with MAU. This study was conducted in 17 (M/F: 4/13) stable RTx. No change was made in the medical treatment of the patients. All cases received 50 mg/day losartan therapy for 12 wk. Renal functions and MAU were determined 12 and 6 wk and just before the treatment as well as sixth and twelfth week of the treatment in all patients. Losartan satisfactorily lowered systemic blood pressure. A significant reduction in MAU was observed from 103 ± 53 μg/min at the beginning to 59 ± 25 μg/min in the sixth week and 47 ± 24 μg/min in the twelfth week (p=0.0007 and 0.0005, respectively). From the sixth week of the treatment, the therapy significantly decreased hemoglobin, hematocrit and erythrocyte levels but did not change mean leukocyte and platelet counts, urea, creatinine levels and creatinine clearances. No serious side‐effect was observed during the study.

Efficacy of losartan in patients with primary focal segmental glomerulosclerosis resistant to immunosuppressive treatment

Abstract. Usta M, Ersoy A, Dilek K, Özdemir B, Yavuz M, Güllülü M, Yurtkuran M (Uludağ University Medical School, Bursa, Turkey). Efficacy of losartan in patients with primary focal segmental glomerulosclerosis resistant to immunosuppressive treatment. J Intern Med 2003; 253: 329–334.

Long-term Effects of Losartan on Proteinuria and Renal Function in Patients with Renal Amyloidosis

Objective : To investigate the effect of the angiotensin II receptor antagonist losartan on proteinuria in secondary amyloidosis cases. Material and Methods : Sixteen patients with renal biopsy-proven AA amyloidosis with proteinuria were included in the study. All the patients had received colchicine treatment for at least 18 months. The patients were divided into two groups with similar age and gender distributions. Eight patients were given losartan at a dose of 50 mg/day for 12 months and the other 8 patients served as controls. Mean arterial blood pressure, proteinuria, serum albumin level and renal function were determined at the initiation of the study and after 1 and 12 months. Results : There were no significant differences in proteinuria, serum albumin level, renal function or mean arterial blood pressure at the initiation of the study. In the losartan group daily proteinuria decreased significantly from 5.2 - 0.7 g at the initiation of the study to 3.9 - 1.2 g at 1 month and 3.6 - 0.8 g at 12 months, while in the control group it changed from 4.6 - 1.0 g to 4.7 - 1.0 g and 6.1 - 1.2 g, respectively. The increment at 12 months was significant. After 12 months of treatment with losartan, proteinuria was significantly lower in comparison to the degree of proteinuria in the control group. Serum albumin level increased significantly in the losartan group but was unchanged in the control group. In the control group, creatinine clearance showed a significant decrease. There was no significant difference in mean arterial blood pressure measurements, serum creatinine levels, total protein, albumin and creatinine clearance levels between the two groups. Conclusions : Losartan seemed to prevent an increase in proteinuria without altering the creatinine clearance level in patients with amyloidosis type AA during a 12-month period. This indicates that losartan may be used to decrease proteinuria in this patient group. However, our results are only preliminary and need to be confirmed by larger studies.

Prevalence of Transfusion Transmitted Virus Infection and its Effect on Renal Graft Survival in Renal Transplant Recipients

Objective : Little is known about the prevalence of transfusion transmitted virus (TTV) infection in renal transplant recipients (RTxs) and its effects on allograft survival. We investigated the prevalence of TTV and its effects on liver injury and graft survival in RTxs. Material and Methods : The study was performed in 33 consecutive RTxs (8 females, 25 males) and 100 blood donors (35 females, 65 males). A nested polymerase chain reaction was used to detect TTV DNA in serum. Serum creatinine and alanine aminotransferase (ALT) levels and 24-h protein excretion were determined in both TTV-positive and -negative patients. The total number of blood transfusions, the duration of hemodialysis and the total duration after transplantation were recorded in RTxs. In addition, hepatitis B surface antigen (HbsAg), anti-hepatitis C virus (HCV) and hepatitis G virus DNA antibodies were determined in all patients. Results : TTV DNA was detected in 51.5% of RTxs and in 7% of the control group and this difference was statistically significant ( p < 0.01). In the RTx group, 64.7% of TTV-positive and 56.2% of TTV-negative patients had undergone a previous blood transfusion. However, the blood transfusion replacement rate, total duration of dialysis therapy and posttransplant period did not differ between these two groups. Five (15.1%) patients in the RTx group had abnormal liver function tests (ALT >40 IU/l). Of these patients, 2 were anti-HCV-positive, 1 was HBsAg-positive and anti-HCV- plus TTV DNA-positive and the serologic tests of the remaining 2 patients were all negative. Among the TTV-positive patients, 2 (11.7%) were anti-HCV-positive, 1 (5.8%) was HBsAg-positive and 3 (17.6%) were HGV DNA-positive. The baseline serum creatinine levels did not differ significantly between the TTV-positive and -negative patients, being 1.5 - 0.6 and 1.4 - 0.6 mg/dl, respectively (p > 0.05). Two of the TTV-positive patients and 1 of the TTV-negative patients had proteinuria. A 1-year follow-up of TTV-positive and -negative patients demonstrated neither acute nor chronic graft rejection. Conclusion : In RTxs, TTV infection was more prevalent than in the normal population. In our patients the virus did not have an important effect on renal graft rejection and did not cause liver injury. However, the question of whether TTV infection may affect graft survival requires further long-term investigation in larger groups.

Lower gastrointestinal tract hemorrhage due to ectopic pancreatic tissue in a renal transplant recipient: a case report.

MANY transplant recipients (RTx) experience gastrointestinal (GI) complications. For example, GI bleeding, particularly from a gastroduodenal ulcer, is a common complication that carries a significant risk of mortality. Ectopic pancreatic tissue is found in about 2% of postmortem examinations, particularly in the stomach and duodenum, followed by the jejunum, Meckel’s diverticulum, and ileum. Presence of this ectopic tissue is no longer a rare condition, but its unusual clinical manifestations, locations, and complications are of clinical interest, Although it rarely incites mucosal bleeding. Because we did not find any data regarding ectopic pancreas and its complications in the literature of RTx, we herein report a case of jejunal ectopic pancreatic tissue presenting as massive GI bleeding in a patient 9 years after renal transplant surgery.

A family with IgA nephropathy and hereditary lymphoedema praecox

Abstract. Usta M, Dilek K, Ersoy A, Alper E, Özbek S, Özdemir B, Filiz G, Yavuz M, Güllülü M, Yurtkuran M (Uludağ University Medical School, Bursa, Turkey). A family with IgA nephropathy and hereditary lymphoedema praecox (Case Report). J Intern Med 2002; 251: 447–451.

A single-dose vancomycin application after standard protocol in peritoneal dialysis patients with recurrent peritonitis

Sir, Peritonitis remains the major cause of catheter removal in peritoneal dialysis (PD) patients suffering from recurrent attacks, despite appropriate antibiotic therapy. Bacteria such as coagulase-negative staphylococci (CNS) from the exit site of the catheter and contaminated dialysis fluids can grow into microcolonies in biofilms on the surface of the catheter [1,2]. In the preliminary study, we evaluated the outcome of administration of a single-dose intracatheterial vancomycin just after primary response to the treatment of the last peritonitis attack with cefazolin in continuous ambulatory PD patients with recurrent peritonitis. Among 166 patients who underwent routine PD, six cases with recurrent peritonitis attacks were treated with initial empiric antibiotic therapy consisting of intraperitoneal cefazolin given in each exchange for gram-positive organisms. The characteristics and data regarding peritonitis attacks are given in Table ​Table1.1. Six patients had three to five peritonitis attacks with intervals of ∼1–7 weeks following the completion of a standard 2- or 3-week course of antimicrobial therapy. Four cases out of six had no history of peritonitis, tunnel or exit-site infection before. One patient (fourth case in the table) had exit-site infection. For S. aureus positive culture, the patient received mupirocin pomade and Sodium Fusidate (1 g/day per oral for 7 days). After therapy, exit-site infection completely resolved, and the two cultures taken afterwards were negative. Then, she also had a peritonitis attack with S. aureus on 21 February 2006. The other patient (third case in the table) had a culture-negative peritonitis attack on 1 May 2006. They were treated with cefazolin. The wives of the two male patients (one having diabetic retinopathy) helped during the dialysis exchanges, and the remaining patients were on their own. Six patients and the two assistants (wives) were negative for nasal carriage state. However, prophylactic mupirocin was given to all patients, but the peritonitis attacks recurred. None of the patients had tunnel infection. After complete resolution of peritonitis by cefazolin alone in the last attack, 50 cc peritoneal dialysate was mixed with 2 g vancomycin after drainage of the entire peritoneal fluid and left in the catheter lumen for 8 h. Then, without drainage, a normal dialysis session was carried out. During the mean follow-up of 25 ± 0.8 months, none of the six patients had recurrence peritonitis. Table 1 Characteristics of peritoneal dialysis patients with recurrent gram-positive peritonitis Many episodes of peritonitis appear to be unrelated to obvious causes. Bacterial biofilm formation on the dialysis catheter represents a concern for PD patients in terms of our ability to eradicate the infection [2]. However, there is sometimes no clear relationship between biofilms and clinical peritonitis. Indeed, one exception may occur in patients with multiple episodes of peritonitis who were likely to have stable biofilms, positive biofilm cultures and a high incidence of catheter loss. Recently, examination by electron microscopy of catheters of patients who experienced PD peritonitis revealed biofilm formation; however, no biofilm formation was found in PD catheters removed from patients without infection [3]. The risk associated with administering cefazolin continuously (in every PD bag) is that the organisms survive and continue dividing in biofilms. Our current antimicrobial protocols may not permit adequate dosing to penetrate the biofilm and be a reason for recurrent episodes of peritonitis. To evaluate the differences in the antibiotic sensitivity patterns of CNS, minimum inhibitory concentrations (MIC) and minimum biofilm eradication concentration (MBEC) assays were compared in CNS isolates from patients with PD-associated peritonitis in a study [4]. In the PD effluent sample from patients with repeat infection, the rate of first-generation cephalosporin (FGC) or gentamicin or both resistances was higher. MBEC results were higher than those with standard MIC assays. Although no vancomycin resistance was observed with MIC assays, a small number of cases were identified with MBEC assays. There was no resistance when a vancomycin/rifampin 1:1 combination was used. All patients with repeat infections had high degrees of FGC resistance, and infection cycles were terminated when their treatment protocol included vancomycin. In conclusion, we assume that adequate antibiotic levels will be achieved within the catheter-contained biofilm with a single dose of vancomycin of 2 g at the end of the treatment course that will prevent recurrent peritonitis and catheter loss. These results are difficult to compare because patient numbers are small. In our opinion, this observation should be confirmed by other investigators. Conflict of interest statement. None declared.

Transfusion-transmitted virus infection in renal transplant recipients.

THE TRANSFUSION-TRANSMITTED virus (TTV) described recently was first detected in peripheral blood and liver tissue of symptomatic patients with posttransfusion hepatitis non A-G. TTV is presumed to be an unenveloped, circular, negative stranded DNA virus containing a genome of 3852 bases. It is proposed that TTV is a member of a new virus family that infects humans, tentatively named the Circinoviridae. TTV infection in humans occurs worldwide, and its prevalence is regionally very different. It was first isolated from patients with posttransfusion hepatitis. Viremia may be transient or persistent, and viremic individuals are often asymptomatic. Its transmission occurs not only by blood transfusion, but also by non-parenteral infection. Renal transplant (RTx) recipients can be infected with TTV because of exposure to the frequent blood transfusions during hemodialysis treatments. However, not much data is available about TTV infection in renal transplant recipients. Therefore, we investigated the prevalence of TTV and the relation to liver diseases in these populations.