Meltem Pekpak

The effect of renal transplantation on pulmonary function

In patients with chronic renal failure, mechanical and hemodynamic changes could occur in the lungs without obvious pulmonary symptoms and findings and their effects could pave the way to pulmonary functional disorders. In this study, pulmonary functional disorders and especially alveolocapillary defects, which are frequently seen in uremia, were determined in renal transplanted patients. Pulmonary functions and diffusion capacity were assessed in uremic patients (n = 20) and in successfully transplanted patients (n = 20) without any lung disease or pulmonary edema symptoms and findings. Patients were selected randomly among outpatients who were followed up in a Nephrology and Transplantation Unit. Forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), and peak expiratory flow (PEF25–75) were measured. Single breath carbon monoxide diffusion test and diffusion lung capacity adjusted for hemoglobin concentration (DLAdj) were done. The means of the spirometric values such as FVC, FEV1 and FEV1/FVC were normal in the nondialyzed uremic group, but the PEF25–75 value (68.7%) and diffusion capacity (DLAdj 72.7%) were found to be slightly low. There were 2 patients with normal values and 18 patients with some functional abnormalities in this nondialyzed uremic group. The means of all spirometric parameters and diffusion capacities were found to be normal in the transplanted group. There were 7 patients with normal function and 13 patients with some functional abnormalities in this transplanted group. When the nondialyzed uremic group and the transplanted group were compared statistically, significant differences were found between their spirometric values (except for FVC) and their diffusion capacities. Even though the uremic patients did not show any symptoms, their pulmonary function tests, especially diffusion capacity, were found to be disturbed. Although the transplanted patients as a group had normal mean spirometric values and diffusion capacity there were nevertheless many individual transplanted patients with defective diffusion capacity and abnormal spirometric values.

Assessment of DNA Oxidation and Antioxidant Activity in Hypertensive Patients with Chronic Kidney Disease

The aim of this study was to evaluate the oxidative DNA damage, antioxidant activity, and effects of antihypertensive drugs on oxidative stress in hypertensive patients with different stages of chronic kidney disease (CKD). Fifty-three non-dialyzed hypertensive CKD patients were included by the study. Serum and urinary 8-hydroxydeoxy guanosine (8-OHdG) levels (as a marker of oxidative DNA damage), serum superoxide dismutase (SOD), and glutathione peroxidase (G-Px) activities (as antioxidant enzymes) were measured. SOD activity was higher and G-Px activity was lower in the patient group as compared to control group. Serum and urinary 8-OHdG levels were found to be higher in the patients with proteinuria greater than 3 g/day than those in the patients with proteinuria less than 3 g/day. It has been determined that G-Px activity and urinary 8-OHdG level were lower in the patients treated with angiotensin-converting enzyme (ACE) inhibitor compared to patients treated with calcium channel blocker. The present data show oxidative DNA damage at a higher level in the patients with proteinuria greater than 3 g/day. In comparison to a calcium channel blocker, an ACE inhibitor seems much more protective against oxidative DNA damage in hypertensive patients with different stages of CKD.

Ultrasonographic Maturation of Native Arteriovenous Fistulae: A Follow-Up Study

Background/aims. Ideal time needed for arteriovenous fistula (AVF) maturation is still controversial. In this study, we aimed to investigate the natural course of AVF maturation and also investigated the factors affecting AVF maturation. Methods. We studied 31 (21M/10F, mean age 55.8 ± 16.2) chronic renal failure patients. We evaluated the patients with color Doppler ultrasound examination before the fistula operation, at the first day, and at the first, second, third, and sixth months. Radial artery (RA) diameter, flow velocity, flow, resistance index, fistula vein diameter, flow velocity, and flow were measured. Results. Patency rates at the first post-operative day and the sixth month were 87.1% and 67.1%, respectively. Cephalic vein flow was 451.2 ± 248.6 mL/min at the first month and 528.6 ± 316.5 mL/min at the sixth month. Baseline RA diameter was lower in failing fistulas than that of patent fistulas. Failing fistulas were more common in women. Conclusion. Blood flow was enough for hemodialysis at the end of the first month. However, fistula maturation had continued until the end of the study; women and patients with low RA diameter are particularly prone to fistula failure. Therefore, especially in these patients, AVF must be created at least three or four months before the predicted hemodialysis initiation time.

Experimentally induced puromycine aminonucleoside nephrosis (PAN) in rats: evaluation of angiogenic protein platelet-derived endothelial cell growth factor (PD-ECGF) expression in glomeruli

BackgroundIn experimentally induced puromycine aminonucleoside nephrosis (PAN) animal models, nephrotic syndrome with minimal change disease and focal and segmental sclerosis-like nephritis similar to that in human is demonstrated; however, the real mechanism of PAN is not yet elucidated. Platelet derived endothelial cell growth factor (PD-ECGF), an endothelial mitogen protein, is believed to take part in microvessel formation and in stimulation of angiogenesis and its expression has not been totally demonstrated in PAN rats yet. In this study, we aimed to examine PD-ECGF expression in acute and chronic PAN induced in rats and find out the association between its expression and the stages of angiogenesis in kidney.MethodsFor the experiment, twenty-four Male Wistar Albino rats were used and divided into four groups; control group (n = 6), pre-proteinuria group (n = 6), acute group (n = 6) and chronic group (n = 6). We compared statistically all data by One-way ANOVA Test followed by Dunn Multiple Comparison Test.ResultsProteinurea levels in control and pre-proteinuria groups were not statistically different; however, it was remarkably higher in the acute nephrosis group and significantly greater in the chronic nephrosis group than control group (p < 0.0025). In pre-proteinuria group, the serum albumin and creatinine clearances also did not significantly differ from the control group. On the other hand, in the acute and chronic nephrosis groups, serum albumin and creatinine clearances progressively decreased (p < 0.05). In our immunohistochemical studies, we showed elevated PD-ECGF expression in glomeruli of acute and chronic PAN rats. Microscopic and ultrastructural appearances of the glomeruli of acute and chronic PAN showed various sequential steps of angiogenesis, macrophages and immature capillaries with primitive lumens and apoptotic endothelial cells in the increased mesangial matrix.ConclusionsIt is reported that acute and chronic PAN progressively increase PD-ECGF expression and following induction of angiogenesis in the affected glomeruli.

Opportunistic pulmonary infection after renal transplantation.

INFECTIOUS complications in kidney transplant recipients are associated with significant morbidity and mortality. The risk of infection is based on two main factors: recent or past exposure to infectious agents, and the patient’s level of immunosuppression. Bacterial infections usually occur in the first month following transplantation, and technical issues related to the procedure can play an important etiologic role. Most febrile illness that occurs in kidney recipients between 1 and 6 months posttransplantation is caused by cytomegalovirus (CMV) and other opportunistic agents. The regimen and level of immunosuppression are important in the pathogenesis of these infectious complications. Kidney recipients whose grafts have come from cadavers tend to develop more frequent and severe infectious complications than living-donor kidney recipients due to the increased level of immunosuppression that is usually needed in the former group. Also, recipients of cadaveric kidneys who receive induction antilymphocyte globulin (ATG) preparations have higher infection rates than those who do not receive this treatment. Further, research has shown that patients who receive azathioprine as their primary immunosuppressive agent have a higher rate of infection than patients on cyclosporine-based regimens. Beyond 6 months, in patients with well-functioning allografts who are on stable maintenance immunosuppression the pattern of infection is similar to that in the general population. Another significant finding is that transplant recipients often develope infection that simultaneously involves several causal agents. This underlines the importance of considering concomitant infection in patients who do not respond to the initial line of treatment. While the incidence of tuberculosis (TB) after kidney transplantation in highly industrialized countries is low, the figure for developing regions is significantly higher. Mycobacterial disease should be considered in any patient with fever of unknown etiology. Most cases of Mycobacterium tuberculosis infection in kidney transplant recipients are due to reactivation of latent TB lesions. Important risk factors for reactivation include nonwhite race, history of active TB, presence of a marked abnormality on a chest radiograph, exposure to a person with a confirmed case of TB, and skin test positivity. In transplant patients, the clinical presentation of tuberculosis may be atypical, and extrapulmonary and miliary tuberculosis is seen more frequently than in the normal population. With regard to fungal infection, in kidney transplant recipients these most commonly present as prolonged fever that does not respond to antibiotic therapy. These infections are associated with very high mortality. The most common fungal infections reported in first series from developing countries were candidiasis, aspergillosis, and cryptococcosis. Several factors influence the development of symptomatic CMV infection after kidney transplantation, but most important are the CMV serologic statuses of the donor and recipient. Symptomatic CMV infection can be primary, can occur due to reactivation of latent infection, or can arise secondary to superinfection. The most severe form is usually observed when a CMV-seronegative recipient receives a graft from a CMV-seropositive donor. Host cell–mediated immunity and the type and level of immunosuppressive therapy influence the development of symptomatic CMV infections. Polyclonal and monoclonal antilymphocyte antibody treatments have the highest CMVpromoting effect, and represent the most important factor in the development of CMV infections after kidney transplantation. Nocardia is a filamentous gram-negative soil organism that can cause pneumonia. This infection also frequently disseminates to the brain and results in abscess formation. The overall mortality associated with nocardiosis in kidney transplant recipients is 25%, but this figure jumps to 44% in patients who have central nervous system involvement.

Assessment of urinary epidermal growth factor level in patients with chronic kidney disease

Chronic kidney disease (CKD) is characterized by progressive loss of functioning nephrons and their replacement with fibrotic tissue over a period of months or years. The causes of CKD are mainly diabetes, hypertension and inflammatory kidney diseases. It is a life threatening disease; if not treated by dialysis or kidney transplant, CKD results in death. CKD has a long latent period in which the disease is clinically silent. Diagnosis and treatment is based mainly on clinical examination and biochemical markers assessing kidney function. Currently, glomerular filtration rate (GFR) and albuminuria are the ideal markers to assess kidney function. Unfortunately patients with CKD may have no symptom until the glomerular filtration rate (GFR) falls below 15ml/min.1 New biomarkers which are able to reflect kidney damage at an earlier stage is required to improve management and decrease the morbidity and mortality of the patients with CKD.