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.

[Gadolinium for DSA in two patients with azotemia: Images of suitable quality and risk of acute renal failure]

BACKGROUND

Gadolinium is an alternative angiographic contrast agent in patients with impaired renal function and high risk for iodinated contrast adverse reaction. We report two cases of acute renal failure caused by gadolinium (0.6 and 0.9 mmol/kg of body weight) after the execution of digital subtraction angiography (DSA) to produce diagnostic-quality images in two elderly diabetic patients with pre-existing renal insufficiency. Both patients needed dialysis treatments for as long as a few weeks until their renal function improved. In our opinion, and according to the guidelines of European Society of Urogenital Radiology, gadolinium has not been assessed as less nephrotoxic than iodinated contrast agents. In fact, 1.8 to 4.8 g of iodine, equally attenuated with a relatively high dose (0.2 to 0.4 mmol) of a gadolinium chelate, is a low iodine dose and could hardly have any important nephrotoxic effects.

CONCLUSIONS

The maximum dose of gadolinium-based contrast agents should never exceed 0.2 to 0.4 mmol/kg in azotemic patients who are undergoing DSA, even though these doses of gadolinium may not provide images of suitable quality for diagnosis and intervention.

[Local therapy with platelet-derived growth factors for chronic diabetic ulcers in haemodialysis patients]

BACKGROUND

The increasing number of diabetic patients who need dialysis treatment is the cause for the growing interest of nephrologists in ulcers of the lower limbs. It has been reported that platelet-derived growth factors, such as PDGF and TGF beta 1, are able to heal skin lesions due to diabetes. Therefore, a platelet gel (PG) has been developed to locally treat foot ulcers with a limited number of applications (3+/-1.7). METHOLOGY AND PATIENTS: The PG is a mix of concentrated platelets and cryoprecipitate activated by batroxobin in the presence of calcium chloride (or gluconate) that must be applied to the wound for three days. The surgeon and the dermatologist should then plan successive treatments because the necrotic tissue needs to be removed. We treated a 62-year-old diabetic man, who has been under treatment with insulin since the age of 36 and has been dialysed for three years. His right lower leg was amputated and he developed a chronic left foot ulcer that resulted in many septic episodes. His ulcer recovered in two months after 8 PG applications.

CONCLUSIONS

Conventional therapy is not successful in 15-20% of diabetic feet. Uraemia and malnutrition may represent important risk factors for foot ulcers in diabetic patients who need advanced technology to stimulate tissue repair. The use of platelet growth factor may ameliorate ulcer healing thus reducing disease-associated morbidity and lowering health care costs.

Novel splicing and missense mutations in autosomal dominant polycystic kidney disease 1 (PKD1) gene: expression of mutated genes

Autosomal dominant polycystic kidney disease (ADPKD) is a common disorder mostly characterized by cyst formation in kidney tubules. The majority of ADPKD cases is caused by mutations in the PKD1 gene, but no prevalent mutation has been reported. By heteroduplex analysis of the 3' single-copy region of the gene, we have searched for mutations in subjects from 40 ADPKD families of Northern Italy. Seven novel polymorphisms and three novel disease-associated mutations (R3718Q, L3851P and IVS45+56del25) were identified. Both missense mutations are located in the major extracellular loop of polycystin-1. The 25 bp deletion inside intron 45 did not affect 5' and 3' consensus splicing sites, but caused a 56 nucleotide out of frame-deletion due to activation of a cryptic 3' splice site in exon 46. The mutated RNA should produce a truncated polycystin 1 at the G binding peptide in the intracellular C-terminal end of the protein. RT-PCR analysis showed that the disease-associated mutations were present in transcribed sequences. In particular, RNA analysis of BHK cells transfected with PKD1 genomic DNA, including the deleted intron, showed that no normal transcript is produced by the deleted gene. This intronic mutation, found in a large pedigree, seems to be associated with a prevalence of cerebrovascular disease.

Autosomal dominant polycystic kidney disease linked to PKD2 locus in a family with severe extrarenal manifestations

We report a large three-generation autosomal dominant polycystic kidney disease family from Northern Italy found to be associated with the PKD2 locus. Hepatic involvement (liver cysts, fibrosis, cholelithiasis or jaundice), subarachnoidal hemorrhage (1 case) and esophageal diverticula (1 case) were present in affected individuals. Among the older members, the males (aged 54-61 years) had hepatic cysts or fibrosis and were on chronic hemodialysis, the females (aged 69 and 70 years) had hepatic cysts, hepatomegaly, mild fibrosis and a mild and moderate renal impairment, respectively. In this family, clinical findings do not differ substantially from those reported for PKD1.

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.

Analysis of polycystic kidney disease with two new microsatellite markers

Two (CA) microsatellite polymorphisms have been studied in 209 subjects from Northern Italy, members of 27 Polycystic Kidney Disease families. Polymorphic alleles were analyzed by using a labelled PCR. Results obtained show that these markers highly improve the presymptomatic diagnosis of the disease in subjects at risk. In addition, our findings suggest that a region with a high recombination frequency should exist between PKD1 and SM7.

Hematological indices of erythropoietin administration in athletes

Recombinant human erythropoietin (EPO), commercially available since 1988, is thought to be used by athletes in aerobic sports for the purpose of increasing oxygen transport and aerobic power. In an attempt to identify EPO administration, we have studied the peripheral blood of 20 subjects practising sports at an amateur level. Automated cytometry was performed on the blood samples before and during 45 days of EPO treatment. The same hematological indices were determined for a control population that consisted of 240 elite athletes from various sports. As expected following EPO treatment, RBC, [Hb] and Hct increased significantly (increments of 8%, 6.3% and 11%, respectively). A significant increase in reticulocyte count was also observed. In addition, automated erythrocyte analysis showed a significant increase in cells with a volume > 120 fl and hemoglobin content (HC) < 28 pg (hypochromic macrocytes, or MacroHypo): 0.06 +/- 0.09% before EPO, 0.48 +/- 0.63% after EPO. The EPO-treated subjects differed from the control population having higher values for Hct, mean corpuscular volume (MCV), Macro and MacroHypo. To investigate the possibility of using such variations in blood parameters to identify EPO treatment, individual values for Hct, MCV, Macro and MacroHypo for treated subjects and controls were plotted. Using the percentages of MacroHypo, a cut-off value surpassed in approximately 50% of the treated subjects and in none of the controls was established.(ABSTRACT TRUNCATED AT 250 WORDS)

Increased uptake of radio labelled white blood cells into abdomen of uremics on peritoneal dialysis

Peritonitis and exit-site tunnel infection are frequent causes of CAPD drop out. We studied 9 patients, 8 treated by CAPD and 1 by IPD. These patients underwent sonographic and scintigraphic study of the abdomen. All scintigraphic examinations showed a visceral uptake. In two cases, sub-clinical bowel inflammation, demonstrated by scintigraphic study, preceded a gram negative peritonitis. The scintigraphic study with radiolabelled white blood cells may be useful in identifying chronic aseptic inflammations and some bowel and exit-site conditions which are possible risk factors in some cases of peritonitis.

Atrial natriuretic peptide and urinary sodium balance during physical exercise

Atrial natriuretic peptide (ANP), plasma renin activity (PRA), plasma aldosterone and urinary fractional excretion of sodium (%FENa) were measured in 22 athletes before and after 1 h running. After exercise the hormones increased significantly, while %FENa decreased. In fact, the percent PRA increases resulted higher than the percent ANP increases with a significant inverse correlation. It is concluded that hemodynamic changes during strenuous and prolonged physical exercise lead to the inhibition of the natriuretic properties of ANP by stimulating the renin-angiotensin-aldosterone system, although a feedback mechanism of modulation between ANP and PRA seems to occur.

Effects of the recombinant human erythropoietin (rHuEPO) administration on hematologic parameters, red cell creatine and 2,3-diphosphoglycerate contents, in patients affected by end-stage renal disease

Twenty patients with renal failure and severe anemia (hemoglobin range 6.6-8.7 g/dl) on thrice-weekly maintenance hemodialysis were treated with recombinant human erythropoietin (rHuEPO). After three months of intravenous (iv) therapy the hemoglobin increase averaged 2 g/dl, and was steadily maintained even after two months of subcutaneous (sc) therapy. The significant increase of macrocyte counts, determined by an automated red blood cell counter after both steps of therapy, suggested the release of young red cells (large cells) into blood circulation. This assumption may be supported by the significant increase of the red cell creatine contents. 2,3-diphosphoglycerate (2,3-DPG) levels of the erythrocytes did not significantly change after rHuEPO administration.

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.

Serum erythropoietin in cross-country skiers

Serum erythropoietin (Epo) activity, hemoglobin (Hb), and hematocrit (Ht) were determined in 21 cross-country skiers during the training season. The Epo levels were not significantly reduced in the skiers relative to the normal population (P less than 0.01 and P less than 0.001, respectively). In 11 athletes Epo, Ht, urinary gamma-glutamyltransferase, N-acetyl-beta-glucosaminidase, and microalbuminuria were determined before and after a 50-km ski race at 1600 m above sea level. A significant increase of these variables (except for Ht) was found after the competition (P less than 0.001). It is concluded that while the reductions in Hb and Ht, which are typical of several endurance exercises, are not accompanied by a renal hypoxia sufficient to stimulate Epo overproduction, the renal hypoxia reached during the strenuous exercise of the race at altitude may be effective in determining blood increases in Epo.

Effects of exercise on haematologic parameters, serum iron, serum ferritin, red cell 2,3-diphosphoglycerate and creatine contents, and serum erythropoietin in long-distance runners during basal training

We studied 18 well-trained male long-distance runners during the basal training. Haematologic parameters, serum iron and ferritin, red cell 2,3-diphosphoglycerate (2,3-DPG) and creatine contents, serum erythropoietin were investigated before and after the daily training and were compared with a group of healthy untrained controls. Red blood cell parameters did not change with the training, even though they were significantly lower than in controls. However, a true anaemic state cannot be suggested because the haemoglobin values fell into the lower limit of the normal range, even before the exercise. A slight but significant increase of neutrophils was found after the exercise, while no alteration of platelet count was observed. Serum iron and ferritin ranged normally. No increase of red cell 2,3-DPG was observed after the exercise, but it was significantly higher than in controls. After the exercise red creatinine was slightly increased. The athletes' erythropoietin was higher than that of controls, and showed a further increase after the training.

Exercise-induced urinary abnormalities in long-distance runners

The post-exercise urine samples from 122 long-distance runners showed evident abnormalities upon microscopic examination in 95% of all subjects. Proteinuria, alone or with microscopic hematuria, was frequently found. Macroscopic hematuria was a rare occurrence. The urine samples collected in 30 runners before, immediately after the race, and 6, 12, 24, 36, and 48 h later showed a significant post-race decrease in the osmolarity and a significant increase in gamma-glutamyl transferase and N-acetyl-beta-glucosaminidase enzyme activity. Plasma renin activity and plasma aldosterone, determined before and after the race in nine runners, showed a significant increase in the post-race samples. The abnormal urinary findings disappeared in all cases within 24-36 h. It can be concluded that urinary abnormalities are very common after exercise. These abnormalities are most often of a "renal" origin, probably due to a temporary hemodynamic impairment, partially of glomerular but principally of tubular function.

[Electrolyte and osmolar changes during extracorporeal ultrafiltration of hepatic cirrhosis ascites]

Ultrafiltration of ascitic fluid with intraperitoneally reinfusion of concentrate was performed on 4 patients with hepatic cirrhosis and ascites. Ascites was removed, ultrafiltered using a parallel plate dialyzer and returned to the peritoneal space via a single catheter. A mean of 4693 ml (range 2000ml-8000ml) of protein free ascitic fluid was removed over the 2-3 hour period of ultrafiltration without evidence of worsening hypovolemia or deterioration of renal function.

Response of plasma aldosterone to sequential ultrafiltration, dialysis and conventional hemodialysis

The response of plasma aldosterone to sequential ultrafiltration dialysis has been studied during 16 sessions and compared with the response to 12 conventional sessions of hemodialysis. During the isolated ultrafiltration phase an important and significant increase in plasma aldosterone and plasma renin activity was observed. There was a substantial removal of extracellular fluid, but no change in plasma biochemistry. During conventional hemodialysis over the same time scale the concentration of plasma aldosterone decreased significantly, plasma renin underwent a small increase and plasma osmolality and plasma potassium decreased. Several possible pathophysiological mechanisms are discussed. We conclude that rapid isosmotic ultrafiltration without change in plasma potassium or sodium, the maintenance of plasma potassium at normal elevated values, and the increase of angiotensin II are factors favoring aldosterone biosynthesis.