Peter Balcke

Incidence of Stroke among Chronic Hemodialysis Patients with Nonrheumatic Atrial Fibrillation

In general, nonrheumatic atrial fibrillation is associated with a high risk of stroke. However, its impact on stroke in the setting of chronic hemodialysis treatment is insufficiently addressed in the literature. We assessed the incidence of stroke among 430 chronic hemodialysis patients and the impact of atrial fibrillation and various other potential risk factors on stroke in a retrospective study covering 1,111.16 patient-years. The overall incidence of stroke was 3.78/100 patient-years. Among patients with chronic atrial fibrillation without any antithrombotic therapy besides regular dialysis anticoagulation, the stroke incidence was 1.0/100 patient-years and did not differ statistically significantly from the rate among patients without this arrhythmia, in whom the incidence was 2.8/100 patient-years (p = 0.220). Conversely, the overall rate of stroke incidence per 100 patient-years was statistically significantly higher in patients with diabetic nephropathy (6.46, p = 0.0036), age >65 years (5.90, p = 0.0001), moderate to severe hypertension (6.8, p = 0.0017), weight gain of >2 kg between dialyses as a marker of poor patient compliance (6.47, p = 0.0433), and antithrombotic therapy with salicylates or warfarin (8.33, p = 0.0002), as compared with corresponding groups without these risk factors. Our data suggest that in contrast to other risk factors nonrheumatic atrial fibrillation in itself is not associated with an increased risk of stroke in patients on maintenance hemodialysis treatment.

Ascorbic acid aggravates secondary hyperoxalemia in patients on chronic hemodialysis.

Excerpt A deficiency in ascorbic acid is found in many patients having chronic hemodialysis treatment, and supplementation is commonly recommended. Ascorbic acid is a metabolic precursor of oxalic ...

Increased serum activity of interleukin-2 in patients with pre-eclampsia.

Pre-eclampsia is a severe complication in pregnancy, manifested by hypertension, proteinuria and oedema, and in the most severe cases leading to fetal death. Immunological mechanisms are generally assumed to be of major importance in the genesis of the disease. Foidart showed anti-laminin antibodies to be involved in preeclampsia. [ 11. Circulating immune complexes [2] and complement activation [3] as well as alterations in T-cell subsets [4] and suppressor activity [5] have also been observed, but still there remains much uncertainty about the pathophysiological mechanisms involved. IL-2 is an important cytokine in the T-cell pathway [6] as it is released by antigenstimulated T cells and enhances alloantigen reactivity by augmentation of cellular cytytoxic function. The question of whether increased cytokine release can be used as a diagnostic marker for an ongoing alteration of maternofetal immune response prompted us to study the serum activity of IL-2 in pregnant women suffering from pre-eclampsia.

Prevalence of preterminal pulmonary thromboembolism among patients on maintenance hemodialysis treatment before and after introduction of recombinant erythropoietin

The prevalence of pulmonary thromboembolism at autopsy was assessed in a retrospective study of a cohort of 185 patients undergoing maintenance hemodialysis treatment who died in the last decade. The overall frequency of thromboembolism was 12.43% in the dialysis population, which statistically was significantly less than in a control group of 8,051 nondialysis patients (21.77%; P = 0.0023). Moreover, pulmonary thromboembolism was less frequently fatal or contributing to death in the dialysis group than in the control group (P = 0.039). The prevalence of pulmonary thromboembolism in the dialysis group remained statistically unchanged over the 10-year period and was independent of a steady increase in the percentage of patients receiving recombinant erythropoietin therapy and the average hematocrit values. The occurrence of preterminal pulmonary thromboembolism was associated with a shorter period since onset of hemodialysis treatment and with infection as cause of death (P = 0. 031; P = 0.029, respectively). No statistically significant influence of the type of basic renal disease, type of dialysis anticoagulation, or dialysis access could be found. Our data suggest that, at least in the preterminal stage, the introduction of recombinant erythropoietin within the last decade had no substantial influence on the prevalence of pulmonary thromboembolism.

MDR1 Gene Expression in Lymphocytes of Patients with Renal Transplants

The MDR1 gene, a multidrug resistance gene, codes for P-glycoprotein which pumps hydrophobic drugs out of the cells. Since cyclosporins also bind to P-glycoprotein and might be pumped by this transmembrane protein, we determined the expression of the MDR1 gene in the lymphocytes of 32 patients with renal transplants. MDR1 RNA expression of lymphocytes was measured by slot blot analysis and compared to the expression of drug-sensitive KB-3-1 cells and multidrug-resistant KB-8-5 cells. MDR1 RNA expression was detected in the lymphocytes of 9 (28%) patients, whereas no expression was seen in the remaining 23 patients. No association between MDR1 RNA expression and transplant function or hematological parameters was observed. However, none of the 6 patients who had transplants for more than 40 months expressed the MDR1 gene in their lymphocytes. In conclusion, expression of the MDR1 gene does occur in lymphocytes of patients with renal transplants and might reduce the immunosuppressive efficacy of cyclosporins through enhanced efflux of cyclosporins.

Effect of vitamin B6 administration on elevated plasma oxalic acid levels in haemodialysed patients

Abstract. Accumulation of oxalic acid resulting in elevated plasma levels is a common finding in uraemic patients. Since vitamin B6 is an important coenzyme in oxalic acid metabolism the influence of vitamin B6 administration on plasma oxalic acid levels was investigated.

Successful Treatment of Hemodialysis-Related Porphyria cutanea tarda with Deferoxamine

End-stage renal failure and long-term hemodialysis treatment promote the development of genetically conditioned porphyria cutanea tarda (PCT). The clinical manifestation is triggered off by unknown factors coexisting with renal insufficiency and hemodialysis. Iron overload is often associated with the disease and is thought to play a key role in its pathogenesis. Iron removal by deferoxamine infusions is regarded as the treatment of choice for patients who cannot undergo repeated phlebotomy procedures and has been successfully used in patients with normal renal function. We report a case of hemodialysis-related PCT and iron overload in whom repeated venesections were contraindicated on account of severe anemia and treatment with deferoxamine led to a striking improvement of symptoms.

Transient hyperoxaluria after ingestion of chocolate as a high risk factor for calcium oxalate calculi.

In 6 male subjects the diurnal variation of urinary oxalic acid excretion was studied after ingestion of chocolate, a food stuff rich in oxalic acid. The ingestion of chocolate caused a striking but transient increase in urinary oxalic acid excretion due to its absorption in the upper gastrointestinal tract. The peak excretion rates occurred 2-4 h after the intake of the chocolate. The peak values were 235% of the fasting excretion rate in the trial with 50 g chocolate and 289% in the trial with 100 g chocolate and reached the amounts found in cases with primary hyperoxaluria. The administration of ranitidine had no influence on oxalic acid absorption. The transient hyperoxaluria observed seems to be an important factor for the formation of calcium oxalate calculi in patients on risk for stone disorders.

Initial body mass indexes have contrary effects on change in body weight and mortality of patients on maintenance hemodialysis treatment

Malnutrition is a relevant risk factor for mortality for patients on maintenance hemodialysis treatment. In a retrospective study including 377 patients who began hemodialysis treatment between 1986 and 2001, we assessed the prevalence of different statuses of nutrition and the impact of the initial status of nutrition on the change in body weight and patient survival. We found an inverse relationship between body mass index (BMI, kg/m2) and the gain in body weight and BMI within 12 months of hemodialysis treatment. Underweight and normal weight patients had a substantial increase in these parameters, greatest in underweight subjects, whereas overweight and obese patients showed only a moderate increase or none (P =.0019, P =.00036). Adjusted mortality rates showed an inverse correlation with the initial BMI (P <.0001). There was a statistically significant difference in the mortality between patients with normal weight and overweight or obesity, respectively, showing a more favorable prognosis in overweight and obese patients (P =.0007; P =.022; log-rank, normal versus overweight, P =.012). Weight loss was the greatest independent risk factor for mortality in general. Adjusted hazard ratio of death was highest in underweight patients (3.999; CI, 2.708 to 5.905; P <.0001) and decreased to 2.251 (CI, 1.795 to 2.822; P <.0001) in normal weight, 1.927 (CI, 1.390 to 2.670; P <.0001) in overweight, and 1.651 (CI, 0.841 to 3.236; P =.1439) in obese subjects when patients with weight loss were compared with patients who preserved their initial weight or gained weight. Overall, the initial BMI has an influence on the change in body weight as well as on patient survival in general and in the case of weight loss in particular.

Excessive myocardial calcinosis in a chronic hemodialyzed patient

SummarySecondary oxalosis in chronic hemodialyzed patients is caused by impaired renal excretion and inadequate removal of oxalic acid during hemodialysis. Ascorbic acid is a precursor of oxalic acid. We report a parathyroidectomized patient with chronic renal failure, on hemodialysis, who received over a period of several months a total dose of 91.0 g ascorbic acid i.v. The plasma oxalic acid level in this patient was 14-fold higher than in healthy persons. Increased oxalic acid synthesis from its precursor ascorbic acid may be responsible for hyperoxalemia, high content of oxalic acid in myocardium, aorta and lung, and calcium oxalate deposition in soft tissues. Application of high doses of ascorbic acid should be avoided in hemodialysed patients with chronic renal failure.