MO639: Evaluation of Glycemic Control and Interday Glucose Variability Using Continuous Glucose Monitoring in Diabetic Hemodialysis Patients

BACKGROUND AND AIMS

Continuous-glucose-monitoring (CGM) facilitates the assessment of interday glucose variability and identification of acute excursions of hyper- and hypoglycemia [1–4).

METHOD

Among 37 diabetic hemodialysis patients who underwent 7-day CGM with the iPRO2 device (Medtronic Diabetes, Northridge, CA, USA), we explored the accuracy of GA and hemoglobin A1c (HbA1c) in assessing glycemic control, using CGM-derived metrics as the reference standard.

RESULTS

In receiver-operating-characteristic (ROC) analysis, the area under the curve (AUC) in diagnosing a time in target glucose range of 70–180 mg/dL (TIR70-180) in <50% of readings was higher for GA {AUC 0.878; [95% confidence interval (CI)] 0.728–0.962} as compared with HbA1c [AUC 0.682 (95% CI 0.508–0.825)] (P < 0.01). The accuracy of GA [AUC 0.939 (95% CI 0.808–0.991)] in detecting a time above target glucose range >250 mg/dL (TAR >250) in >10% of readings did not differ from that of HbA1c [AUC 0.854 (95% CI 0.699–0.948)] (P = 0.16). GA [AUC 0.712 (95% CI 0.539–0.848)] and HbA1c [AUC 0.740 (95% CI 0.570–0.870)] had a similarly lower efficiency in detecting a time below target glucose range <70 mg/dL (TBR <70) in >1% of readings (P = 0.71). Although the mean glucose levels were similar, the coefficient of variation of glucose recordings (39.2% ± 17.3% versus 32.0% ± 7.8%, P < 0.001) and TBR <70 [median (range): 5.6% (0, 25.8) versus 2.8% (0, 17.9)] were higher during the dialysis-on than during the dialysis-off day.

CONCLUSION

The present diagnostic test study shows that among diabetic hemodialysis patients, GA had higher accuracy than HbA1c in detecting a 7-day CGM-derived TIR70-180 in <50% of readings. However, both GA and HbA1c provided an imprecise reflection of acute excursions of hypoglycemia and interday glucose variability.

Stenting of Central Venous Stenoses and Occlusions to Maintain Hemodialysis Vascular Access

Background/Aims: The aim of the study was to evaluate the efficacy of stenting for the treatment of central arm vein obstructions in hemodialysis patients in order to maintain hemodialysis from the affected side. Methods: Fifteen self-expanding (8) and balloon expandable (7) stainless steel stents were implanted in 10 hemodialysis patients for the treatment of symptomatic central arm vein obstructions. Thirteen lesions were treated: 6 subclavian, 4 innominate and 3 restenoses. Results: Stent deployment was successful in all cases leading to resolution of symptoms by correcting the underlying cause of venous hypertension. Follow-up from 3 months to 4 years revealed four deaths from unrelated causes, three restenoses at 1, 3, 4 months and one occlusion at 6 months respectively for a cumulative primary one-year and two-year patency rate of 70%. Conclusion: Stenting of subclavian and innominate venous stenoses and occlusions effectively corrected the underlying lesions responsible for disturbed hemodynamics and, in most cases, prolonged available hemodialysis access from the affected side.

Frequent COL4 mutations in familial microhematuria accompanied by later-onset Alport nephropathy due to focal segmental glomerulosclerosis

Familial microscopic hematuria (FMH) is associated with a genetically heterogeneous group of conditions including the collagen-IV nephropathies, the heritable C3/CFHR5 nephropathy and the glomerulopathy with fibronectin deposits. The clinical course varies widely, ranging from isolated benign familial hematuria to end-stage renal disease (ESRD) later in life. We investigated 24 families using next generation sequencing (NGS) for 5 genes: COL4A3, COL4A4, COL4A5, CFHR5 and FN1. In 17 families (71%), we found 15 pathogenic mutations in COL4A3/A4/A5, 9 of them novel. In 5 families patients inherited classical AS with hemizygous X-linked COL4A5 mutations. Even more patients developed later-onset Alport-related nephropathy having inherited heterozygous COL4A3/A4 mutations that cause thin basement membranes. Amongst 62 heterozygous or hemizygous patients, 8 (13%) reached ESRD, while 25% of patients with heterozygous COL4A3/A4 mutations, aged >50-years, reached ESRD. In conclusion, COL4A mutations comprise a frequent cause of FMH. Heterozygous COL4A3/A4 mutations predispose to renal function impairment, supporting that thin basement membrane nephropathy is not always benign. The molecular diagnosis is essential for differentiating the X-linked from the autosomal recessive and dominant inheritance. Finally, NGS technology is established as the gold standard for the diagnosis of FMH and associated collagen-IV glomerulopathies, frequently averting the need for invasive renal biopsies.

Multiple Myeloma Presenting as MPO-ANCA Associated Microscopic Polyangiitis

Reports on the association of multiple myeloma with systemic vasculitis are rare and concern, vasculitis due to crystalglobulin deposition in vessels or to polyarteritis nodosa PAN-like type necrotizing vasculitis. The association of multiple myeloma with MPO-ANCA positive microscopic polyangiitis has not yet been described. We report a case of a 72 year old man, who was referred to our clinic for evaluation of recent onset renal failure (serum creatinine 8mg/dl), proteinuria 2g/day, severe anemia (hematocrit 16%) and fever accompanied by malaise, anorexia, weigh loss, myalgia and arthralgia. These symptoms appeared 20 days prior to his admission. There was no evidence of any infection. The renal biopsy showed necrotizing crescentic glomerulonephritis. The MPO-ANCA were positive. Bone marrow biopsy revealed infiltration with IgG-lambda neoplastic plasma cells. The patient was treated with hemodialysis, plasma exchange, corticosteroids and cyclophosphamide. Even though his clinical situation and renal function improved gradually, two months after his admission, he developed acute respiratory insufficiency accompanied by heavy hemoptysis, patchy infiltration on chest X-rays, due to lung vasculitis and died. Multiple myeloma should be considered in the differential diagnosis of hematological neoplasms capable of causing paraneoplastic ANCA positive microscopic polyangiitis.

Unit dosing of darbepoetin alfa for thetreatment of anemia in patients with end-stage renal disease being switched from recombinant human erythropoietin: Results of a phase IIIb, 27-week, multicenter, open-label study in Greek patients

BACKGROUND

Darbepoetin alfa is an erythropoietis-stimulating glycoprotein with a ∼3-fold longer t1/2 and greater biological activity compared with recombinant human erythropoietin (rHuEPO).

OBJECTIVE

The objective of this study was to evaluate the efficacy andtolerability of long-term (24-week) darbepoetin alfa treatment in maintaining hemoglobin (Hb) concentrations in the target range of 10 to 13 g/dL in patients undergoing dialysis; the patients were switched from rHuEPO to a less-frequent dosing regimen of darbepoetin alfa without an increase in dose.

METHODS

In this Phase IIlb, open-label, multicenter study, patients withend-stage renal disease (ESRD) undergoing dialysis who were receiving rHuEPO BIW or TIW at baseline were switched to darbepoetin alfa QW; patients receiving rHuEPO QW were switched to darbepoetin alfa Q2W Administration of darbepoetin alfa was by the same route as previous rHuEPO administration (IV or SC). Patients received darbepoetin alfa for 24 weeks, including a 20-week drug titration period followed by a 4-week, stable-dose evaluation period. The mode, dose, and frequency of administration of darbepoetin alfa were compared with those of baseline rHuEPO. Tolerability assessment was based on spontaneous reporting and laboratory tests (hematology, vital sign measurement, iron status, and biochemistry).

RESULTS

The study comprised 173 patients who were divided into 2 groups by route of administration (IV group, n = 146; SC group, n = 27). Mean (SE) adjusted increases in Hb concentration from baseline to the evaluation period for patients receiving darbepoetin alfa QW were 0.94 (0.32) g/dL and 0.38 (0.30) g/dL for the IV or SC routes, respectively (P = 0.004 and NS, respectively). For patients receiving darbepoetin alfa Q2W the mean (SE) adjusted increases in Hb concentration were 0.08 (0.53) g/dL and 0.48 (0.35) g/dL for the IV and SC routes, respectively (both, P = NS). No significant differences in IV/SC dose ratio were observed between the 2 routes of administration. In addition, no increases in darbepoetin alfa dose were observed. The most commonly reported adverse events were hypertension (8 patients [5%]) and vascular access thrombosis (4 [2%]). The incidence of treatment-related adverse events was 6 (3%).

CONCLUSIONS

Darbepoetin alfa effectively maintained Hb concentrations within the target range without an increase in dose, even at a reduced dosing frequency. Overall, darbepoetin alfa was well tolerated.

Matrix metalloproteinases, atherosclerosis, proteinuria and kidney disease: Linkage-based approaches

Matrix metalloproteinases (MMPs) are important enzymes of extracellular matrix (ECM) degradation for creating the cellular environments required during development and morphogenesis. MMPs, collectively called matrixins, regulate also the biological activity of non matrix substrates such as cytokines, chemokines, receptors, growth factors and cell adhesion molecules. Enzymatic activity is regulated at multiple levels. Endogenous specific inhibitors of metalloproteinases (TIMPs) participate in controlling the local activities of MMPs in tissues. The pathological effects of MMPs and TIMPs are involved in cardiovascular disease (CVD) processes, including atherosclerosis and in a number of renal pathophysiologic alterations, both acute and chronic, linking them to acute kidney injury, glomerulosclerosis and tubulointerstitial fibrosis. This review presents an overview of the place of MMPs in atherosclerosis, proteinuria and kidney disease as a subject of considerable interest, given the differentiated and ambiguous role of MMPs in the progression of these diseases.

Role of asymmetrical dimethylarginine in the progression of renal disease

Asymmetric dimethylarginine (ADMA) is a naturally occurring amino acid found in tissues and cells that circulates in plasma and is excreted in urine. It inhibits nitric oxide synthases (NOs) and produces considerable cardiovascular biological effects. Several studies have suggested that plasma concentrations of ADMA provide a marker of risk for endothelial dysfunction and cardiovascular disease. In animal and in population studies ADMA has been associated with progression of CKD. Several mechanisms may be involved in this association, such as compromise of the integrity of the glomerular filtration barrier and development of renal fibrosis. This review summarizes the existing literature on the biology and physiology of ADMA focusing on its role in the progression of renal disease.

Glomerular filtration rate estimation in patients with type 2 diabetes: creatinine- or cystatin C-based equations?

AIMS/HYPOTHESIS

It is argued that GFR estimation (eGFR) using cystatin C-based equations (eGFRcys) is superior to that using creatinine-based equations (eGFRcre). We investigated whether eGFRcys are superior to eGFRcre in patients with type 2 diabetes.

METHODS

GFR was measured in 448 type 2 diabetic patients using (51)Cr-EDTA-measured GFR (mGFR) as the reference standard. Bias, precision and accuracy of eGFRcys and eGFRcre were compared.

RESULTS

The most accurate eGFRcre equation (Chronic Kidney Disease Epidemiology Collaboration [CKD-EPI]), which produced the highest proportion of estimates that were within 30% and 10% of the reference standard (80.7% and 38.0% of samples, respectively) had a bias of 7.1 and precision of 12.0 ml min(-1) 1.73 m(-2). The calibrated eGFRcys with the highest accuracy (Tan-C), which produced the highest proportion of estimates that were within 30% (78.8%) and within 10% (39.0%) of the reference standard had a bias of -3.5 and precision of 18.0 ml min(-1) 1.73 m(-2). Moreover, the areas under the receiver operating curve were higher with eGFRcre (CKD-EPI and Modification of Diet in Renal Disease [MDRD]) than with eGFRcys for the diagnosis of mild (mGFR <90 ml min(-1) 1.73 m(-2)) and moderate (mGFR <60 ml min(-1) 1.73 m(-2)) chronic kidney disease. In patients with mGFR ≥90 ml min(-1) 1.73 m(-2), CKD-EPI was the least biased, the most precise and the most accurate equation.

CONCLUSIONS/INTERPRETATION

In patients with type 2 diabetes, eGFRcys do not currently provide better eGFR than eGFRcre. At present, compared with eGFRcys, eGFRcre are better at predicting the stage of chronic kidney disease. In addition, CKD-EPI seems to be the best equation for eGFR in patients with normal renal function.

Network-centric Analysis of Genetic Predisposition in Diabetic Nephropathy

Diabetic nephropathy is a serious, long-term complication of diabetes and the leading cause of end-stage renal disease throughout the world. Although this disease is progressively imposing a heavier burden on the health care system, in many aspects it remains poorly understood. In addition to environmental influences, there is abundant evidence in support of genetic susceptibility to microvascular complications of nephropathy in diabetic patients. Familial clustering of phenotypes such as end-stage renal disease, albuminuria and kidney disease have been reported in large scale population studies throughout the world demonstrating strong contribution of inherited factors. Recent genome-wide linkage scans identified several chromosomal regions that are likely to contain diabetic nephropathy susceptibility genes, and association analyses have evaluated positional candidate genes under linkage peaks. In this review we have extracted from the literature the most promising candidate genes thought to confer susceptibility to diabetic nephropathy and mapped them to affected pathways by using network-centric analysis. Several of the top susceptibility genes have been identified as network hubs and bottlenecks suggesting that they might be important agents in the onset of diabetic nephropathy.

Aggressive systemic mastocytosis associated with mesangioproliferative glomerulonephritis

BACKGROUND/AIMS/METHODS

Aggressive systemic mastocytosis (ASM) is a subtype of systemic mastocytosis, which comprises a heterogenous group of disorders characterized by infiltration of bone marrow, skin, liver, spleen, lymph nodes and gastrointestinal tract by neoplastic mast cells. There is lack of data on the association of ASM with renal involvement, as kidney is not among the known organs affected by ASM.

RESULTS/CONCLUSIONS

To the best of our knowledge, this is the first case of ASM associated with mesangioproliferative glomerulonephritis and monoclonal gammopathy of undetermined significance, without the presence of nephrotic syndrome. The patient's clinical course and the intriguing family history, along with the treatment selection are described. Finally, the proposed possible pathophysiological mechanisms explaining the renal involvement of our patient are discussed.

Adaptation and validation of the Kidney Disease Quality of Life-Short Form questionnaire in the Greek language

AIM

The aim of this study was to examine the validity, reproducibility and internal consistency of a Greek translation of the Kidney Disease Quality of Life-Short Form (KDQOL-SF) questionnaire.

METHODS

The KDQOL-SF questionnaire was translated from English to Greek and was administered in 240 randomly selected patients undergoing hemodialysis in six Renal Units in Greece. The instrument's validity was tested by examining the association between patient's KDQOL-SF scores and comorbidity assessed with the Index of Coexistent Disease. Reproducibility was examined by readministering the questionnaire in 50 randomly selected patients within 1 month. Internal consistency was assessed by estimating Cronbach's alpha coefficient.

RESULTS

Patients were divided into two groups according to the severity of comorbidity assessed with the Index of Coexistent Disease. Those with less comorbid conditions had significantly higher scores in most components of the KDQOL-SF questionnaire, confirming its validity. The correlation coefficients between the two administrations of the instrument ranged from 0.88 to 0.98 for each of the main components, which was above the desired level of 0.85. Cronbach's alpha coefficient ranged from 0.91 to 0.92 for the various components, values well above the minimum desired 0.70 level.

CONCLUSIONS

The present study shows that the Greek version of the KDQOL-SF questionnaire has high validity, reproducibility and internal consistency. Production of validated translations of the KDQOL-SF questionnaire in various languages will help promote health-related quality of life of end-stage renal disease patients all over the world.

Coagulation factors as biological risk markers of endothelial dysfunction. Association with the thrombotic episodes of chronic hemodialysis patients

BACKGROUND AND AIM

The aim of our study was to assess the coagulation factors as endothelial dysfunction markers and prospectively their association with thrombotic episodes in chronic hemodialysis patients.

PATIENTS AND METHODS

Fifty-four randomly selected patients on chronic hemodialysis (HD), 34 men and 20 women were included in this study. Their mean age was 56 years and the mean hemodialysis duration was 53.0861.92 months. The variations of tissue factor pathway inhibitor (TFPI), thrombomodulin (TM) and von Willebrand factor (vWF) were studied. The above-mentioned parameters were measured before and after HD session. Low molecular weight heparin (tinzaparin) was administered to all patients during hemodialysis. The results were compared with those obtained from 20 healthy volunteer-controls, age and sex matched. After the initial assessment, all patients were followed for a period of 15 months.

RESULTS

Two patients experienced one hemorrhagic event each, regarding the upper and/or the lower gastrointestinal tract. Twenty patients showed at least one thrombotic episode. Eleven patients presented fistula thrombosis, four angina pectoris incidents and five thrombosis of the lower limbs. The rest of the patients did not experience any clinical symptomatology that could be attributed to coagulation disorders. Parameter differences between patients and controls were statistically significant (p<0.005 for TFPI and p<0.001 for TM and vWF) and were improved after hemodialysis session. The age and the elevated levels of the vWF were found to be significantly different (p<0.03 and p<0.02 respectively) between the groups of patients who experienced or not thrombotic episodes.

CONCLUSIONS

Coagulation factors TFPI, TM, and vWF are increased in hemodialysis patients and the clinical disorders are mainly thrombotic episodes. The age of patients and the elevated levels of vWF are associated with the thrombotic incidents. Hemodialysis contributes in the improvement of these coagulation factors, which could be considered as biological risk markers of endothelial dysfunction in chronic HD patients.

Physical training in patients on hemodialysis has a beneficial effect on the levels of eicosanoid hormone-like substances

OBJECTIVE

The aim of this study was to evaluate the changes in the levels of vasoactive eicosanoid hormone-like substances PGE2, PGI2 and TXA2 in hemodialysis (HD)patients who were following a long-term physical training program during the hemodialysis session.

DESIGN

A total of 50 patients with Chronic Kidney Disease (CKD) (stage 5)on hemodialysis and 35 healthy individuals who served as controls (C) were evaluated. The 50 CKD patients were divided into two groups: the HD group consisted of 31 patients who received usual care without any physical activity during the hemodialysis sessions, while group HD/Exer included 19 patients who followed a program of physical exercise for six months. Plasma levels of PGE2, 6-Keto-PGF1alpha (the stable derivative of PGI2) and TXB2 (the stable derivative of TXA2) were measured by reliable enzymo-immunoassay methods (EIA) in HD and HD/Exer patients before and after the hemodialysis sessions as well as in the group of C.

RESULTS

The plasma levels of PGE2 and 6-keto-PGF1alpha in group HD Exer/before patients were higher than those in group HDbefore (20.39+/-5.82 and 1449.19+/-553.41 vs 17.68+/-5.36 and 1295.10+/-384.43 pg/ml, p=0.044 and p=0.067, respectively), while the plasma levels of TXB2 were lower in HD Exer/before patients compared to HDbefore(499.76+/-67.51 vs 608.01+/-80.23 pg/ml, p=0.041). The plasma levels of PGE2 and 6-keto-PGF1alpha in group HD Exer/after patients were significantly higher compared to those in HDafter patients (23.01+/-5.70 and 1618.19+/-435.07 vs 16.57+/-4.97 and 1005.44+/-317.16 pg/ml, p<0.001 and p<0.040, respectively). However, significantly lower values in the plasma levels of TXB2 in HD Exer/after compared to HDafter patients (363.10+/-51.91 vs 439.75+/-62.34 pg/ml, p=0.030) were detected. As expected, PGE2 and 6-keto-PGF1alpha values were lower in C than in the groups of patients with CKD.

CONCLUSIONS

The data indicate that exercise training during HD exerts a beneficial effect on the levels of the vasoactive eicosanoid hormone-like substances in patients on HD.

Effects of intradialytic exercise training on health-related quality of life indices in haemodialysis patients

OBJECTIVE

To assess the effects of intradialytic exercise training on health-related quality of life indices in haemodialysis patients.

SUBJECTS/PATIENTS

Thirty-five patients on haemodialysis, with a mean (SD) age of 48.8 (13.9) years, volunteered to participate in the study. They were randomized either to rehabilitation group (group A: 19 patients), following a 10-month intradialytic exercise training programme or to control group (group B: 14 patients). After the randomization, two of the patients, one of each group, withdrew from the study for reasons unrelated to exercise training.

METHOD

All patients at the beginning and the end of the study underwent clinical examination, laboratory tests and a treadmill exercise testing with spiroergometric study for the evaluation of their aerobic capacity (Vo(2peak)). A formal psychosocial assessment, which included affective (Beck Depression Inventory), health-related quality of life (Quality of Life Index, Living Questionnaire of Minnesota, Life Satisfaction Index and Short Form-36 questionnaire) and personality (Eysenck Personality Questionnaire) parameters, was evaluated at beginning and end of the study. The dose of erythropoietin was changed as needed, according to the level of the haemoglobin, aiming to keep it at 11 (2) g/dL during the study.

RESULTS

Baseline values were similar between the two groups. After training in group A, Vo(2peak) was increased by 21.1% (P<0.05) and exercise time by 23.6% (P<0.05). Moreover, group A showed a decrease in self-reported depression (Beck Depression Index) of 39.4% (P<0.001). In addition, trained patients demonstrated a significant improvement in Quality of Life Index (from 6.5 (1.8) to 9.0 (1.3), P<0.001) and Life Satisfaction Index (from 44.8 (8.6) to 53.0 (5.6), P<0.001), and an increase in the Physical Component Scale of the SF-36 (from 40.5 (5.6) to 44.5 (5.5), P<0.05), while the Mental Component Scale remained unchanged. Multiple regression analysis indicated that the improvement in quality of life depended on the participation in exercise programmes, the effects of training and the reduction in the level of depression. No changes were observed in Eysenck Personality Questionnaire by the end of the study, while all the above parameters remained almost unchanged in the controls.

CONCLUSION

The results demonstrated that intradialytic exercise training improves both physical functioning and psychological status in haemodialysis patients, leading to an improvement of patients' quality of life.

Enhanced oxidative stress with a gradient between plasma and muscle interstitial fluid in patients with end stage renal failure on hemodialysis

OBJECTIVE

The concentration of 8-iso-prostaglandin-F2 alpha (8-iso-PGF2 alpha in biological fluids has been considered as the most reliable biochemical index of the lipid peroxidation and oxidative stress in patients with several pathological conditions including end stage renal failure. However, there is no reference regarding the influence of Hemodialysis (HD) on the values of 8-iso-PGF2 alpha in the muscle Interstitial Fluid (IF) of patients with end stage renal failure. The aim of our study was to determine 8-iso-PGF2 alpha concentration in the IF during hemodialysis and the gradient between plasma and IF in patients with end stage renal failure.

DESIGN

In this study, two microdialysis probes were inserted into the vastus lateralis muscle of the right leg of six male patients with end stage renal failure who were on hemodialysis, and in six healthy males (controls). The samples of IF (12 dialysate fluids) were collected after an equilibration of 30 min: a) during the 1st hour preceding hemodialysis (group CRF0), b) during the 1st, 2nd, 3rd and 4th hour while on hemodialysis (groups CRF1, CRF2, CRF3 and CRF4) and c) during the 1st hour following hemodialysis (group CRF5). At the end of the above periods and simultaneously, blood samples were drawn from the arteriovenous fistula. In the controls, the IF samples (twelve dialysate fluids) were collected during a period of one hour and the blood samples at the end of this period. The levels of 8-iso-PGF2 alpha were measured with an enzyme-immunoassay method. Statistical evaluation was carried out with the statistical program NCSS 2000 and the ANOVA test.

RESULTS

Plasma and IF levels of 8-iso-PGF2 alpha in the patients were significantly higher than in controls at base line. During hemodialysis, the 8-iso-PGF2 alpha rose progressively both in plasma and IF but remained higher in plasma than in IF.

CONCLUSIONS

Lipid peroxidation is higher in patients on hemodialysis than in controls but it is lower in the IF compared to plasma. The mechanism for this gradient is speculative.

Digital clubbing as an unusual complication associated with severe secondary hyperparathyroidism: Report of two cases

Digital clubbing due to secondary hyperparathyroidism has been described as an unusual complication among patients with chronic kidney disease undergoing maintenance hemodialysis therapy. Although the pathogenesis of digital clubbing is unknown, certain growth factors such as platelet-derived growth factor and hepatocyte growth factor have been associated with this clinical syndrome. Two patients of our renal unit population presented this unique clinical feature bilaterally, among the other clinical findings of severe secondary hyperparathyroidism. Both patients were subjected to parathyroidectomy. Histological examination revealed diffuse hyperplasia of parathyroid glands. Despite the improvement of clinical symptoms and laboratory findings of secondary hyperparathyroism after parathyroidectomy, digital clubbing remained unchanged.

Angina pectoris and intensive intravenous iron treatment in hemodialysis patients

BACKGROUND

Intravenous iron and erythropoietin are commonly used for the treatment of anemia in end stage renal disease (ESRD) patients. Even though i.v. iron is proven to be very effective, there is great concern regarding its possible toxic effects. The aim of our study was to evaluate the possible correlation between iron administration and the incidence of angina pectoris in hemodialysis patients.

METHODS

The study sample consisted of 10 stable coronary heart disease patients, receiving chronic hemodialysis treatment. The patients followed consecutively three different i.v. iron dose regimens according to their needs. Their standard monthly laboratory measurements were correlated with the incidence of angina pectoris and i.v. iron treatment.

RESULTS

Hematocrit, ferritin, serum iron and mean rhEPO dose were related to the total amount of administered iron. Angina pectoris was related to intensive iron treatment, age and platelet count. Total white blood cell count were related to hemodialysis duration, platelet count and serum triglycerides.

CONCLUSION

It is suggested that the intensive intravenous iron treatment (300 mg/week) is associated with the increased incidence of angina pectoris in stable coronary heart disease patients receiving hemodialysis.

ProCol vascular bioprosthesis for vascular access: midterm results

BACKGROUND/AIMS

This study aimed to evaluate the safety and efficacy of the ProCol vascular bioprostheses as vascular access (VA) material, especially in patients with a history of prior failed access.

METHODS

During a 20-month period, 25 arteriovenous (AV) bovine vein grafts were placed in 24 hemodialysis (HD) patients for VA. All patients presented with failed autologous access sites.

RESULTS

Graft placement was successful in all patients with no procedure-related complications. Follow-up from 6-26 months gave primary 6-month, 12-month and 24-month patency rates of, respectively, 90%, 80% and 70%. Graft characteristics in cannulation and hemostasis were very satisfying.

CONCLUSION

Our midterm results demonstrated that the ProCol vascular bioprosthesis was a promising material for VA with good patency and low complication rates.

Association between Hyperhomocysteinemia and Ultrasonographic Atherosclerotic Indices of Carotid Arteries in Chronic Hemodialysis Patients

BACKGROUND

Atherosclerotic cardiovascular events are a major cause of morbidity and the main cause of mortality in hemodialysis patients. Hyperhomocysteinemia--which is a consistent finding in uremic patients--is considered an independent risk factor for cardiovascular disease (CVD). However, the relationship between plasma homocysteine (Hcy) concentrations and atherosclerotic CVD has not been extensively investigated.

PATIENTS AND METHODS

37 patients undergoing chronic hemodialysis and 30 healthy individuals (control group), sex- and age-matched, were included in this study. Both healthy controls and hemodialysis patients underwent echo-Doppler carotid artery examination. The right and left carotid arteries were assessed separately. Our observation included measurements of the ultrasound images of the intimal wall thickness, the lumen diameter and the atherosclerotic plaques. We determined plasma Hcy, vitamin B12 and folic acid levels and serum cholesterol, triglycerides, HDL, ApoA-I, ApoB-100, Lp(a), CRP, albumin and creatinine levels in blood samples from both studied groups. We also determined the urea reduction ratio in the patient groups. The epidemiological as well as the biochemical data were correlated with the findings of the carotid artery examination.

RESULTS

Plasma Hcy levels were significantly increased in hemodialysis patients compared to controls (33 +/- 12.3 vs. 12.27 +/- 7.47 micromol/l, p < 0.001). Intimal wall thickness, lumen diameter and number of atherosclerotic plaques of both carotid arteries were significantly higher (p < 0.01 or p < 0.001) in patients compared to controls. There was a significant positive correlation between plasma Hcy levels and the number of the atherosclerotic plaques (r = 0.41, p < 0.01 in the right and r = 0.49, p < 0.001 in the left carotid artery). Lumen diameter was significantly (p < 0.01) associated with age, MAP and CRP levels. Significant correlations (p = 0.05-0.01) were also found between the number of the plaques and age as well as the duration of hemodialysis, while folic acid levels were inversely correlated with the number of the plaques.

CONCLUSIONS

Both hyperhomocysteinemia and atherosclerotic indices of the carotid arteries are more prevalent in hemodialysis patients compared to healthy controls. Elevated plasma Hcy levels were associated with the carotid artery atherosclerotic indices in chronic hemodialysis patients.

Thrombotic thrombocytopenic purpura associated with rapidly progressive lupus nephritis: report of two cases

There are a few reported cases in the literature of thrombotic thrombocytopenic purpura (TTP), associated with systemic lupus erythematosus (SLE). We describe two cases of TTP which have been presented during rapidly progressive lupus nephritis, with grand-mal seizures, thrombocytopenia and microangiopathic hemolytic anemia. Both cases were treated with hemodialysis, plasma exchange, corticosteroids, cyclophosphamide and intravenous gamma-globulin. In both cases the TTP was improved but not the renal function. Further experience is needed to determine whether intensive and prompt treatment with plasma exchange, corticosteroids and chemotherapy leads to a favorable outcome, in cases of TTP associated with SLE.

The response of muscle interstitial F2-isoprostane (8-ISO-PGF2alpha) during dynamic muscle contractions in humans

8-Iso-prostaglandin F2alpha (8-iso-PGF2alpha) is a characteristic F2-isoprostane which is produced in humans via a free radical-catalysed lipid peroxidation mechanism of arachidonic acid, independent of the cycloxygenase pathway. The measurement of the plasma levels of 8-iso-PGF2alpha was shown to be the most reliable biochemical index of oxidant stress status in the human body. However, there is no reference in literature of local muscle interstitial 8-iso-PGF2alpha production during dynamic muscle contractions. The aim of the present study was to evaluate the response of 8-iso-PGF2alpha during intensive exercise with a cycle ergometer. Two microdialysis probes with CMA-60 microdialysis catheters were inserted into the vastus lateralis muscle of the right leg of six healthy male volunteers. After insertion, these microdialysis probes were attached to a perfusion pump that perfused ringer acetate solution at a rate of 0.3 microl/min. The dialysate fluid samples were collected: (a) during a 30 min rest period and (b) during a 30 min period of dynamic exercise with a cycle ergometer at 150 Watts. Our measurements showed that the levels of 8-iso-PGF2alpha in the interstitial fluid (IF) of the vastus lateralis muscle increase significantly during exercise (from 113.5 +/- 30.2 to 329.9 +/- 69.8 pg/ml, P = 0.05). In conclusion, dynamic muscle exercise produces a local increase of the IF levels of 8-iso-PGF2alpha due to local peroxidation injury of the contractive muscle. The microdialysis method is widely applied, easily repeated and it could contribute in evaluating the local lipid muscle peroxidation during intensive exercise.

Outcomes of long-term exercise training in dialysis patients: comparison of two training programs

BACKGROUND

Exercise training has been shown to improve the low functional capacity and quality of life in dialysis (HD) patients. However, there are no data about the outcome of long-term exercise training and, also, the adherence of HD patients in such long-term renal rehabilitation programs. Therefore, the aim of this study was to evaluate the effects of 2 modes of long-term physical training on HD patients' physical fitness, perception of health and overall life situation.

PATIENTS AND METHODS

Forty-eight HD patients, free of any other systemic disease, who followed 2 modes of exercise training for 4 years, were studied. Half of them (group A) were randomly assigned to participate in a supervised outpatient exercise training program (3/weekly) on the non-dialysis days, while the other half (group B) followed a training program with stationary bicycles during their HD sessions (3/weekly). The measured domains of physical fitness and well-being every year were: aerobic capacity, as estimated from a modified Bruce treadmill exercise test and spiroergometric study, the patients' perception of health, the overall life situation and the employment status.

RESULTS

During the 4-year study, there were 8 drop-outs in group A and 5 in B. No adverse effects of the exercise programs were reported. The 1 year of exercise training resulted in 38% in group A (16 patients, who remained in the study) and 31% in group B (18 patients) improvement of exercise time, and a 47% increase in group A of peak oxygen consumption (VO2peak) and a 36% in group B in comparison to baseline value. After 3 additional years of training, significant improvements were also noted in exercise time (by 53% in group A and by 43% in B) and VO2peak (by 70% in group A and by 50% in group B), as well as in other gas exchange variables in comparison to baseline values. However, the improvements in group A were more pronounced than in B. Interestingly, the gains in exercise capacity were more enhanced in the first year of training in both groups. After 4-year training, significantly more patients in both groups perceived their health and overall life situation as well, compared to baseline. In addition, perception of improved health was higher in group A. The increase in the proportion of patients working was also higher in group A than B after the 4-year training.

CONCLUSION

HD patients can adhere to long-term physical training programs on the non-dialysis days, as well as during hemodialysis with considerable improvements in physical fitness and health. Although training out of HD seems to result in better outcomes, the drop out rate was higher.

Combined treatment with low-dose pravastatin and fish oil in post-renal transplantation dislipidemia

BACKGROUND

The most common cause of post-transplant dyslipidemia is the use of corticosteroids and cyclosporin-A (CyA). The HMG-CoA reductase inhibitors have emerged as the agents of first choice in the treatment of post-transplant hyperlipidemia in combination with low fat diet. The objective of this study was to evaluate the efficacy of combined treatment with low-dose pravastatin and fish oil in post-renal transplantation dislipidemia.

PATIENTS AND METHODS

Twenty-four renal transplant patients, 15 men and 9 women aged from 30 to 60 years with stable renal function were included in this study. All patients were transplanted from living related donors and were given a stable triple immunosuppressive therapy, with methylprednisolone, azathioprine and CyA. All patients were also given a standard diet containing 1 g/kg BW protein, reducing the daily fat to less than 30%, and maintaining at least a 1:1 ratio of saturated to polyunsaturated (or monounsaturated) fats. A dosage of 20 mg pravastatin (pravachol) and 1 g of fish oil (prolipid) were added to the diet after dinner, according to our protocol. Blood samples were taken after each study period for total cholesterol, LDL-cholesterol, triglycerides, Apo A(1), Apo B, Lp(a), creatinine, CPK and fibrinogen determination.

RESULTS

At the end of the therapeutic protocol with pravastatin a significant reduction (p < 0.02) of total and LDL-cholesterol was observed, but no significant change in triglycerides, HDL, Lp(a), Apo A(1), Apo B and fibrinogen was shown. At the end of the therapeutic protocol with pravastatin and fish oil supplement significant changes were seen in TC (p < 0.02), TG (p < 0.03), LDL-C (p < 0.03), Apo A(1) (p < 0.04) and Apo B (p < 0.05) concentrations. There were no significant changes in HDL-C and Lp(a) concentrations. Renal function and cyclosporine levels were not changed during and after the study. CPK was increased only in one case.

CONCLUSIONS

It is suggested that if the response to the diet is inadequate, the use of combined treatment with low-dose pravastatin and fish oil is a more effective strategy than the pravastatin treatment alone for changing the lipid profile after renal transplantation.

Effect of sympathetic and plasma renin activity on hemodialysis hypertension

BACKGROUND

The reasons for poor control of blood pressure in hemodialysis (HD) patients are not clear, while patients have achieved their desirable dry weight and excess weight are not different between the hypertensive and normotensive patients. A link between sympathetic activity and HD hypertension could be an alternative explanation.

PATIENTS AND METHODS

We studied the effect of sympathetic and plasma renin-aldosterone activity of 10 hypertensive patients, 5 men and 5 women, aged from 30 to 60 years. The results were compared to those of another 10 normotensive hemodialysis patients. Blood samples were taken before HD and at the end of a 4-hour HD session for plasma aldosterone (ALDO), renin activity (PRA), adrenaline and noradrenaline determination. One month dialysis records, which includes 13 dialysis sessions and 26 blood pressure readings for each patient were used, for pre-dialysis and post dialysis mean arterial blood pressure (MAP) measurement.

RESULTS

Pre-dialysis plasma adrenaline was 124.12 +/- 12.93 pg/ml vs. 121.12 +/- 14.71 pg/ml and plasma noradrenaline was 260.88 +/- 140.86 pg/ml vs. 138.11 +/- 122 +/- 32 pg/ml for hypertensive and normotensive patients, respectively. Post-dialysis plasma adrenaline and noradrenaline levels were 119.37 +/- 8.81 pg/ml vs. 120.62 +/- 15.35 pg/ml and 210.44 +/- 126.71 pg/ml vs. 94.88 +/- 64.05 pg/ml for hypertensive and normotensive patients, respectively. Pre-dialysis PRA was 8.70 +/- 6.37 ng/ml/h vs. 2.77 +/- 1.8 ng/ml/h and plasma ALDO was 457.07 +/- 245.54 pg/ml vs. 197.74 +/- 87.46 pg/ml for hypertensive and normotensive patients, respectively. Pre-MAP was 109.76 +/- 5.21 mmHg vs. 99.28 +/- 7.13 mmHg and post-MAP was 107.22 +/- 6.74 mmHg, vs. 91.61 +/- 7.27 mmHg for hypertensive and normotensive patients, respectively. Plasma ALDO and fluid volume removed by ultrafiltration were found to be significantly correlated (p < 0.05). PRA and plasma adrenaline-noradrenaline levels were not correlated with MAP or body weight alterations.

CONCLUSIONS

It is suggested that sympathetic activity, as it was expressed by plasma catecholamine alterations, is not associated with hemodialysis hypertension.

Hypertension in chronic hemodialysis patients: current view on pathophysiology and treatment

BACKGROUND

Hypertension accounts for 65 - 85% of patients beginning dialysis, and dialysis alone controls hypertension in over 50% of patients.

PATIENT AND METHODS

We have surveyed the status of BP control in 113 hemodialysis patients, 66 men and 47 women, aged 59 +/- 13 years old, with a mean duration on hemodialysis 42 +/- 44 months. The following measurements were recorded: predialysis mean arterial pressure (pre-MAP), post-dialysis MAP (post-MAP), percentage of change in MAP, pre-dialysis weight, post-dialysis weight, fluid removed by ultrafiltration during each dialysis session, interdialytic weight gain and excess weight over the desirable dry weight.

RESULTS

Our results showed a hypertension prevalence of 59% (hypertension defined as pre-MAP +/- 110 mmHg). MAP was not different between men and women, and only 4.5% of patients had isolated systolic hypertension. All hypertensive patients were on treatment with antihypertensives. Reduction in post-MAP by > or = 5% (controlled by ultrafiltration) was found in 68.5% of hypertensive and in 87.5% of normotensive patients. Age, primary renal disease, time on dialysis and adequacy of dialysis were not correlated with pre-MAP. Excess volume and interdialytic weight gain were found to correlate with pre-MAP (p = 0.03). Also, the weekly dosage of EPO had a significant correlation with pre-MAP (p = 0.03). No differences were found among four classes of antihypertensive drugs regarding the BP control. Patients with hypertension requiring one drug achieved a significantly (p < 0.05) lower pre-MAP than the group of patients receiving three or more drugs. In conclusion, hemodialysis population shows high prevalence of hypertension, resistant to antihypertensive treatment.

CONCLUSION

Current methods of hemodialysis are not effective in controlling BP. This implies that more insight into the role of excess volume and vasomotor systems in the pathogenesis of dialysis hypertension is warranted.

Effective treatment of secondary hyperparathyroidism in hemodialysis patients by titration of intravenous calcitriol dosage

AIM

Effective treatment of secondary hyperparathyroidism (HPTH) with intravenous (i.v.) administration of calcitriol in hemodialysis patients.

PATIENTS AND METHODS

The current study evaluates the use of i.v. calcitriol dosing in relation to the severity of the HPTH in 35 hemodialysis patients with serum phosphate < 6.5 mg/dl. Arbitrarily, patients with plasma IPTH levels (intact PTH) between 288 and 576 pg/ml (288 pg/ml = four-fold the upper normal limit) were given initially 1 microg i.v. calcitriol at the end of each dialysis (group A, n = 15). Patients with IPTH between 577 and 864 pg/ml received 2 microg i.v. calcitriol (group B, n = 10) and patients with IPTH more than 865 pg/ml were given 3 - 4 microg i.v. calcitriol (group C, n = 10). As IPTH levels decreased, the dose of i.v. calcitriol was also decreased gradually. Patients were followed-up for 4 months after the end of calcitriol treatment.

RESULTS

During the i.v. calcitriol treatment period, the observed plasma IPTH concentrations compared with the baseline values were significantly lower (p < 0.01 for A and B group and p < 0.05 for C group) from the sixth month onwards in group A and C and from the third month onwards in group B. At the 12th month of follow-up, all patients being off i.v. calcitriol treatment for four months, a sharp and significant increase (p < 0.01 for group A and B and p < 0.05 for group C) of plasma IPTH was recorded in all three groups of patients. Alkaline phosphatase was also gradually decreased in all studied groups. Serum Ca and P remained unchanged in most patients.

CONCLUSION

In conclusion, the study presented here demonstrates that the titration of i.v. calcitriol dosage according to the severity of HPTH is an effective and safe treatment of HPTH in chronic hemodialysis patients. It also shows that parathyroidectomy could be avoided in the majority of patients with severe HPTH, if an appropriate dose of calcitriol not aggravating hyperphosphatemia is administered.

Lipid peroxidation and antioxidant defense mechanisms in rat renal tissue after daunorubicin administration

Redox cycling compounds such as daunorubicin have been assumed to be toxic because they stimulate reactive oxygen-mediated lipid peroxidation. Furthermore, both DT-diaphorase and glutathione (GSH) have been regarded as protective cellular compounds against daunorubicin cardiotoxicity, but their role in daunorubicin nephrotoxicity remains unclear. To investigate this issue, 10 adult Wistar rats were twice injected with a single dose of 20 mg/kg body weight daunorubicin into the tail vein; the interval between injections was 48 h. A control group of 10 rats were injected with normal saline. One day after the second injection, all the animals were sacrificed and their kidneys were analyzed for malondialdehyde (MDA) as an index of lipid peroxidation, DT-diaphorase activity, and GSH and glutathione disulphide (GSSG) content. A significant increase of MDA concentration (2.41 vs. 1.64 p < 0.001) and DT-diaphorase activity (0.2 vs. 0.12, p < 0.001) was found in the renal tissue of daunorubicin injected rats. In contrast, GSH and GSSG levels were decreased in those animals (566 vs. 1282, p < 0.001 and 115 vs 187, p < 0.01, respectively). The results of this study give evidence that a high dosage of daunorubicin induces lipid peroxidation in renal tissue of rats stimulating the activation of DT-diaphorase and the detoxificative depletion of GSH.

Lipid peroxidation after acute renal ischemia and reperfusion in rats: the effect of trimetazidine

Lipid peroxidation is a critical pathway of reactive oxygen species inducing tissue injury in postischemic acute renal failure. In order to evaluate the effect of renal ischemia reperfusion on kidneys, renal tissue malondialdehyde (MDA, nmol/g wet weight) concentration was measured in 29 male Wistar rats subjected to a midline abdominal incision and 60 min occlusion of the left renal artery. A right nephrectomy was performed at the beginning of the ischemic period. The animals were separated in four groups. Groups 1 (n = 7) and 3 (n = 7) underwent 60 min of ischemia and 15 min of reperfusion, respectively. Groups 2 (n = 8) and 4 (n = 7) were subjected to the same procedure but, in addition, they received 2.5 mg/kg TMZ into the tail vein 2 h prior to the left renal artery occlusion. A significant elevation of MDA after 60 min of ischemia (1.43 vs. 2.1, p < 0.001), which was augmented after 15 min of reperfusion (1.4 vs. 3.72, p < 0.001) was observed. Furthermore, there was a significant reduction of renal tissue MDA in ischemic rats treated with TMZ (group 3) (2.1 vs. 1.52, p < 0.001). The maximum reduction of renal tissue MDA was observed in ischemic-reperfused rats (group 4) that had received TMZ (3.72 vs. 1.36, p < 0.001). It is suggested that lipid peroxidation is a critical event in postischemic acute renal failure, and TMZ is a useful protective agent of renal damage from oxygen free radicals.

Renal hemodynamics in hypertensive renal allograft recipients: effects of calcium antagonists and ACE inhibitors

Hypertension present in more than 50% of successfully renal transplanted patients and its prevalence has slightly increased since the introduction of cyclosporine A. Twenty patients, 9 women and 11 men aged from 30 to 58 years, with stable cadaveric renal allograft function and moderate to severe hypertension, were included in the study. Renal artery graft stenosis causing hypertension were excluded. All patients were given triple drug immunosuppressive treatment with methylprednisolone, azathioprine and cyclosporine A (CsA) and their hypertension was treated with a nifedipine dose of 20 mg twice daily. To evaluate the effect of ACE inhibitors on renal hemodynamics and hypertension, a 4 mg/daily dose of perindopril was added to the above regimen for two months. Effective renal plasma flow (ERPF) decreased from 208 +/- 54 to 168 +/- 61 ml/min and renal vascular resistance (RVR) increased from 75 +/- 12 to 88 +/- 17 mm Hg/ml/min (P < 0.05 and P < 0.01, respectively). Mean blood pressure was significantly (P < 0.001) reduced by the combination of both agents in comparison to the blood pressure control by monotherapy with nifedipine. It is suggested that the combination of both antihypertensive agents was more effective than monotherapy with nifedipine in controlling blood pressure, but less favorable on the renal hemodynamic response in hypertensive renal transplant patients who were maintained on CsA.

Management of moderate to severe hypertension and proteinuria by nifedipine retard and perindopril after renal transplantation

Clinical studies of treatment with angiotensin converting enzyme (ACE) inhibitors in patients with glomerular disease have shown the clinical efficacy of these agents. Fifteen renal transplant hypertensive and proteinuric patients on triple drug treatment with cyclosporin (CSA), azathioprine and methylprednisolone entered the therapeutic protocol of this study. All patients followed up last year had stable graft function (serum creatinine less than 2 mg/dl). Hypertension was treated by nifedipine retard and occasionally by furosemide. Patients with a renal artery graft stenosis, at least as judged by technetium-scan imaging were excluded. In order to evaluate the possible role of ACE inhibitors on hypertension and proteinuria, perindopril 4 mg/daily was added for two months to the above regimen. Two patients, who showed a reversible deterioration of renal function during treatment and three who did not comply to the therapeutic protocol were excluded. Systolic and diastolic blood pressure as well as 24 h urine protein was found to be significantly (p < 0.01) reduced at the end of the two-month combined treatment with perindopril and nifedipine retard in comparison to the result of monotherapy with nifedipine retard. GFR and ERPF showed no significant difference (NS) between the two modes of treatment. It is suggested that the combined treatment with nifedipine retard and perindopril is more effective than the monotherapy with nifedipine retard in the management of moderate to severe post-transplant hypertension and proteinuria of renal transplant patients.

Renal transplantation in asymptomatic carriers of hepatitis B surface antigen

The aim of the present study was: (a) to assess the effect of HBsAg on the survival of both renal grafts and patients, and (b) to determine the outcome of HBV chronic infection after renal transplantation. Fourteen patients seropositive for HBsAg but asymptomatic before renal transplantation (group A) were included in the study. The results were compared to those of 14 transplanted patients (group B) seronegative for HBsAg with similar age and immunosuppressive treatment. Four patients received a graft from a living-related donor and 10 patients from a cadaver donor in each group. Eight of 14 patients of group A showed, after renal transplantation, chronic hepatitis, which was not observed in any of the group B patients (p < 0.01). The rate of acute rejection episodes was significantly greater (p < 0.05) in group B than in group A. The graft survival was found to be similar in both groups at the 1st year, but significantly less (p < 0.01) in group B than in group A at the 5th year after transplantation. The survival of patients was found to be significantly less in group A than in group B at the 1st (p < 0.05) and 5th years (p < 0.01) after transplantation. In 2 patients of group A and 1 of group B anti-HCV was found, while HDAg plus anti-HD was found in 1 patient of group B. The HBV-DNA was found in 4 of 8 alive patients of group A.(ABSTRACT TRUNCATED AT 250 WORDS)

Theophylline modulates erythrocytosis after renal transplantation

Erythrocytosis occurs in 10-15% of renal transplant recipients and there is evidence that the production of erythropoietin is modulated by adenosine. We prospectively evaluated the effects of theophylline, a nonselective adenosine antagonist, in 8 patients with erythrocytosis after renal transplantation. All patients were given triple-drug immunosuppressive therapy with methylprednisolone (8 mg/daily), azathioprine (2 mg/kg b.w. daily) and cyclosporin A (4 mg/kg b.w. daily). After an 8-week course of theophylline treatment (Theodur 300 mg x 2 daily), the mean serum erythropoietin levels were significantly reduced (from 61 mIU/ml before to 16.5 mIU/ml after treatment, p < 0.05). Also the hematocrit was reduced from 0.58 before to 0.50 after treatment (p < 0.05). The previous requirement of monthly phlebotomy was eliminated in all transplant recipients. The above effects were reproducible when the patients were rechallenged with theophylline after a recovery period. It is suggested that theophylline modulates the production of erythropoietin as well as the hematocrit levels in patients with erythrocytosis after renal transplantation and may be useful in the treatment of this condition.

Influenza vaccination on renal transplant patients is safe and serologically effective

Since immunosuppressed patients are at higher risk of serious influenza virus infection than healthy subjects, we decided to study the serological effectiveness of influenza vaccination on renal transplant patients, despite the theoretical aspect that such treatment could induce glomerular lesions through an immunological process. Forty transplant patients aged from 20 to 50 years with well functioning renal graft and no febrile episode were studied. Blood samples were collected before the intramuscular injection of 0.5 ml of multivalent influenza vaccine (PASTEUR MERIEUX SERUM VACCINS), at one and at two months after the vaccination. Before vaccination, the antibody titers to influenza virus ranged from 0 to 1/20 and after vaccination from 1/20 to 1/320. One month after vaccination 17/40 (42.5%), 18/31 (58%) and 16/33 (48%) patients showed a four-fold or greater increase of serum influenza antibody titers to antigens A/H3N2, A/H1N1 and B, respectively. A similar response at two months in relation to the first month response rate after vaccination was found in 15/17 (88%), 18/18 (100%), and 15/16 (93%) of transplant patients for the above mentioned three antigens. Side-effects were observed in two of the studied patients. Serum creatinine and urine protein were not changed. Also acute graft rejection episodes were not observed. It is suggested that influenza vaccination is safe and serologically effective on renal transplant patients.

Treatment of urinary tract infections with ciprofloxacin after renal transplantation

As urinary tract infections in immunosuppressed renal transplant patients present a major therapeutic problem for clinicians in charge of renal units, the efficacy of the antibiotic ciprofloxacin in such cases was tested in this study. Twenty-six patients, 16 women and 10 men, aged 20 to 56 years, who developed urinary tract infection (UTI) from 6 months to 10 years after renal transplantation were included in the study. Of these patients, 20 (77%) showed cystitis and/or prostatitis and 6 (23%) clinical symptomatology of acute or recurrent pyelonephritis. Patients with obstructive uropathy were excluded. Urine culture was positive for E. coli in 16/26 patients (61.5%) and for proteus mirabilis, klebsiella, staphylococcus aureus in 10/26 (38.5%). All patients were given ciprofloxacin 250 mg x 2 daily for 10 days and the results of the treatment were compared to those of 60 nontransplant patients (controls) with UTI. Fourteen patients (54%) were completely cured and 10(38%) showed improvement, while the respective results in the controls were 68% (41/60) and 28%. Relapses occurred in two patients, one in each group. Serious side effects were not observed. It is concluded that ciprofloxacin is an effective and safe drug for the treatment of UTI in renal transplant patients.

Effect of calcium antagonist on renal graft function

Studies in experimental models of renal ischemia have shown that calcium antagonists are effective in the protection from the ischemic insult. Thirty-five patients who received a kidney graft over a 2-year period (nifedipine group) were compared with 35 consecutive transplanted patients (control group). The two groups were compatible with regard to age, sex, duration of hemodialysis, graft matching, and total number of blood transfusions. The patients in the nifedipine group were given 0.2 mg nifedipine (10% solution) through the renal artery immediately after revascularization, and also nifedipine per os during all the study periods. Adequate diuresis (1 mL/min) was obtained in 14.5 +/- 37.2 and 43.9 +/- 46.8 h after transplantation in the nifedipine and control groups respectively (p < 0.01). The frequency of acute tubular dysfunction and the mean serum creatinine concentrations were found to be higher in the control group. Fractional excretion of sodium was not found to be different in the two groups on the first day, but it was significantly lower by the first week after transplantation in the nifedipine group (p < 0.05). Acute rejection episodes were found to be more frequent in the control group during the first 6 months after transplantation (p < 0.05). It is suggested that nifedipine is effective in the protection of renal function after transplantation.

Transposed basilic vein-brachial arteriovenous fistula: an alternative vascular access for hemodialysis

Twenty-five brachial-basilic arteriovenous (AV) fistulas with transposed basilic vein for alternative vascular access were created in 22 chronic hemodialysis patients. This surgical procedure was performed under brachial block or general anesthesia. After a longitudinal skin incision that was made in the inner side of the arm, the basilic vein was exposed, transposed subcutaneously, and anastomosed end-to-side to the brachial artery. The follow-up was between 7 and 24 months. Early complications were hemorrhage, thrombosis, steal syndrome, and swelling of the arm. Among the late complications were failure of the fistula because of thrombosis and multiple stenosis at the site of venipuncture. The accumulated one-year patency rate of fistulas was 81%. The complications of high-output cardiac failure or local infection were not seen in our study. On the basis of our results, the brachial-basilic AV fistula with transposed basilic vein is a useful and safe second- or third-choice vascular procedure for hemodialysis patients, in particular for women without good quality of vessels.

Reduction of CyA nephrotoxicity by nifedipine during and after experimental in situ renal preservation

In order to evaluate the role of nifedipine in the nephrotoxic effect induced by both ischemia and CyA, 18 healthy mongrel dogs were used. The kidneys were exposed and subjected to 1 h of ischemia by clamping both renal vessels. To the renal artery of the first group of kidneys (n = 9), 300 mL of cold Euro-Collins solution, in which nifedipine (Bay a 1040-10 mg) was diluted, was infused for 15 min (nifedipine group), while 300 mL of cold Euro-Collins solution plus 10 mg of placebo (Bay a 1040-placebo) was infused to the renal artery of the second group (n = 9) of kidneys (placebo group). Venous drainage was effected through a plastic cannula. All animals received through a nasogastric catheter 20 mg/kg cyclosporine A at the beginning of the ischemia. The 1 h of ischemia was divided in a 15-min period of cold ischemia and 45-min of warm ischemia, at the end of which the clamps were removed. During the 2 h (30 min x 4) after reperfusion, 10 mg of nifedipine and placebo was administered additionally by a peripheral vein to the nifedipine and the placebo group, respectively. Then the kidneys were removed for histological study. Urine volume and creatinine and urea clearances of the nifedipine group were significantly higher than the placebo group (p < 0.001) while TxB2 levels were higher in the placebo group in all studied periods (p < 0.001). Urine sodium, FENa, osmolar clearance, and LDH values were significantly different (p < 0.01), but the urine potassium concentration was not different in the two groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Influenza vaccination in chronic hemodialysis patients. The effect of zinc supplementation

Since influenza increases the mortality of chronically ill patients we decided to study the effectiveness of influenza vaccination in hemodialysis (HD) patients. Nineteen HD patients aged from 20 to 60 years, on unrestricted diet and with no febrile episode, were studied. Blood samples were collected before the intramuscular injection of 0.5 mL multivalent influenza vaccine (Inflexal Berna) and every 2 weeks thereafter. At the end of 4th week a second vaccination was done and a dosage of 200 mg of zinc acetate (60 mg elemental zinc) was given daily to each patient for at least 4 weeks. Before vaccination the antibody titers to influenza virus ranged from 1:10 to 1:80 and after vaccination from 1:20 to 1:640. Four weeks after vaccination 6/19 (31.5%), 8/19 (42%), and 10/19 (52.5%) patients showed a fourfold or greater increase at serum antibody titers to antigens A/Singapore, A/Sichuan, and B/Beijing, respectively. The zinc supplementation after the second vaccination induced a similar increase of serum antibody titers to the A/Singapore but some even greater increase of the antibody titers to the A/Sichuan and B/Beijing. Serum immunoglobulins and complement components C3/C4 were not changed during this study. It is suggested that about 50% of uremic patients respond to the influenza vaccination and that zinc treatment does not increase this responsiveness.