Exercise training and endothelial progenitor cells in haemodialysis patients.

Haemodialysis patients have few endothelial progenitor cells (EPCs) and an unfavourable cardiovascular outcome. The effects on peripheral blood CD34(+) cells and EPCs of a 6-month walking exercise programme were studied. Thirty dialysis patients (20 males, age 67 +/- 12 years) were prescribed exercise (two daily 10-min home walking sessions at moderate intensity, group E, n = 16) or not prescribed exercise (control, group C, n = 14). On entry and after 6 months peripheral blood CD34(+) cells, EPCs (assessed as CD34(+) cells co-expressing AC133 and vascular endothelial growth factor receptor 2 [VEGFR2], and as endothelial colony-forming units [e-CFU]) and exercise capacity (6-min walking distance, 6MWD) were evaluated. In group E, 6MWD and e-CFU increased significantly during the study period, with no significant changes in CD34(+) or CD34(+) AC133(+) VEGFR2(+) cell numbers. The change in e-CFU was directly and significantly correlated to patient-reported training load. Group C showed no significant change in any variable. In haemodialysis patients, moderate-intensity exercise selectively increased the number of e-CFU.

Favorable effects of prostacyclin infusion in a patient given a renal transplant and with severe vascular disease secondary to diabetes--a case report.

Microangiopathy is one of the most frequent diseases in diabetic patients. A diabetic man with a kidney transplant and with severe and progressive vasculopathy with early necrosis of the fingers and toes was submitted to three prostacyclin (PGI2) intravenous infusions (5 ng/kg/min for forty-eight hours) during a period of two months. Three months after the last infusion, radiographs of the hands and feet showed a marked reduction in the extent of the vascular calcifications and healing of the ischemic-necrotic areas. The authors discuss the immediate and later effects of PGI2 infusion in a case of diabetic vascular disease.

Clinical and radiological features of bone disease in long-term (15 or more years) hemodialysis patients.

Fifteen patients on regular dialytic treatment for more than 15 years were given X-rays of the skull, spine, shoulders, wrists, pelvis and knees with the purpose of studying the principal skeletal and articular alterations due or not due to the uraemic status. Serum calcium, phosphorus, parathyroid hormone, alkaline phosphatase and basal aluminium were recorded. Osteopenia was evident in all the patients. Ten of whom (67%) showed alterations due to hyperparathyroidism. Nine patients presented the marks of dialysis spondyloarthropathy; in 14/15 cases geodes were present in the wrists, humeral heads or hip-joints; in ten patients there were multiple amyloid lesions. Two patients with serum basal aluminum above 100 micrograms/L showed the typical radiographic marks of osteomalacia. The majority of the long-term survivors showed multifactorial osteo-articular alterations resulting mainly from the combination of hyperparathyroidism and dialysis-related amyloidosis. The less frequent joint alterations were represented by arthrosis, enthesopathy and chondrocalcinosis. Disability and decreased articular mobility resulted in being mainly due to amyloid osteo-arthropathy.

Non-A, non-B hepatitis and anti-HCV antibodies in dialysis patients.

To define the prevalence of non-A, non-B hepatitis, antibodies to HCV were detected in 193 patients on renal replacement therapy (52 transplant and 141 hemodialysis patients) and in 50 staff members of a Nephrology Department. Unequivocal seroconversion was documented in 5 transplant (9.6%) and in 26 dialysis patients (18.4%). In the dialysis population, the prevalence of anti-HCV antibodies was evaluated in patients grouped according to the number of blood transfusions and to the different sections of dialytic treatment. The most striking findings were the marked differences in the prevalence of anti-HCV antibodies among patients treated in different sections (from 0% to 70%), and the presence of a significant increase in alanine-amino-transferase (ALT) concentrations in 14 anti-HCV negative patients. The results suggest that the diffusion of non-A, non-B hepatitis is mainly transfusion-related, with the possibility of significant environmental diffusion related to the violation of infection-control measures. The current immunoassay is probably unable to detect the actual frequency of the infection.

Exercise capacity and circulating endothelial progenitor cells in hemodialysis patients.

Mobilization of circulating endothelial progenitor cells (EPCs) is increased after acute exercise and training. This study aims to evaluate whether, in a low performance population, EPC levels may be related to exercise capacity in steady state conditions. Study population consisted of sixteen hemodialysis patients. The distance walked in the 6-minute walking test (6 MWD) and the maximal speed attained in an incremental treadmill test were used to assess the exercise capacity. Physical functioning was measured by the scale on the SF36 questionnaire. Quantification of peripheral blood CD34(+) cells and enumeration of EPCs, assessed as CD34(+) cells coexpressing AC 133 and vascular endothelial growth factor receptor-2, were performed. Hemoglobin concentration, white blood cells, high-sensitivity C-reactive protein, total cholesterol, and triglycerides were measured. Statistical analysis examined the relationship between blood progenitors cells versus performance parameters, laboratory parameters, age, body mass index, hemodialysis duration, and erythropoietin therapy. Univariate analysis revealed a significant association between percentage values of EPC and performance parameters only: 6 MWD (r=0.720; p=0.0017), maximal treadmill speed (r=0.721; p=0.0016), and physical functioning score (r=0.506; p=0.0453). A similar statistical association between EPC absolute values and performance parameters was found. No correlation between CD34 (+) and any parameter under study was observed. Multivariate analysis indicated 6 MWD as the most significant independent factor associated with EPC level. EPC percentage value was significantly lower (p=0.0087) in the worse (6 MWD < 300 m, n=8) than in the better performing group (6 MWD > 300 m, n=8). In a group of renal patients, mobilization of EPCs was related to the degree of exercise capacity, suggesting a possible connection with the cardiovascular risk in low performance populations limited by chronic diseases.

Diffuse and severe ischemic injury of the extremities: a complication of umbilical vein catheterization.

We report a case of severe, peripheral, and diffuse tissue ischemia after umbilical vein catheterization (UVC) in a preterm newborn born to a preeclamptic mother. Nitroglycerin ointment was used to treat lesions. The recovery was good but partial loss of the distal phalange of one finger and one toe occurred. This is the first report of peripheral vasospasm occurring after UVC. Topical nitroglycerin, traditionally used to treat peripheral artery catheter-induced ischemic injury, may be useful to treat the same lesions occurring after UVC.

Prevention of hepatitis C virus in dialysis units.

To understand how to prevent the diffusion of hepatitis C virus (HCV) in dialysis units, 289 chronic dialysis patients treated in a renal department from the beginning of 1990 to June 30, 1993, were studied. Patients were screened monthly for alanine aminotransferase values and every 3 months for anti-HCV antibodies. At the beginning of the study the prevalence of anti-HCV antibodies was 24.7%. Two study groups were defined. In the first, anti-HCV-positive patients were treated on separate machines; in the second, 13 anti-HCV-positive and 13 negative patients shared the same machines. Patients in the study were treated with traditional dialysis, employing low-permeability membranes and disposable dialysate circuits on machines without an ultrafiltration control device. The 'universal precautions' were rigorously applied. The use of blood transfusions was markedly reduced. Although new patients starting dialysis treatment revealed a high frequency of HCV positivity (10.8%), the overall prevalence of HCV infection in the department did not increase during the follow-up period. Furthermore, no seroconversion was found in patients on dialysis treatment, not only in the section where anti-HCV-positive patients were treated on separate machines, but also in the section where anti-HCV-positive and anti-HCV-negative patients shared the same machines. The possibility of an intradialytic diffusion of HCV appeared to be very low and the treatment of infected patients on separate machines not strictly necessary.

Histological features of non-A, non-B hepatitis in hemodialysis patients.

In 12 hemodialysis (HD) patients with persistently raised serum alanine amino-transferase concentrations, 6 of which with anti-HCV antibodies, a liver biopsy was performed. The histological examination showed chronic persistent hepatitis or less significant changes in 11 patients and mild chronic active hepatitis in only 1. Non-A, non-B hepatitis seems to demonstrate in HD patients a low tendency to induce an active and progressive liver disease.