H. Kopsa

Secondary oxalosis in chronic renal insufficiency.

The concentration of oxalic acid was determined in the plasma of 15 patients with conservatively treated chronic renal insufficiency and 17 dialysis patients. A cumulation of oxalic acid was found in connection with uraemia. The extent to which plasma oxalic acid concentrations were raised depended on the degree of renal insufficiency and was directly related to the plasma creatinine values in all patients with or without dialysis. In the patients with chronic renal insufficiency the median plasma oxalic acid concentration was 74.4-18.5 (control group 27.0 +/- 7.4) mumol/l. In the dialysis patients the levels were even higher, at 137.5 +/- 56.0 mumol. By means of haemodialysis it was possible to lower the plasma oxalic levels by about the same amount as creatinine concentrations. The higher plasma oxalic acid concentrations seem to be an important pathogenetic factor in the formation of uraemic calcification in various organs. The therapeutic consequences are to increase the duration and frequency of dialysis and to remedy possible vitamin B6 deficiency.

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 ...

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.

Beta-2-Microglobulin for Differentiation between Ciclosporin A Nephrotoxicity and Graft Rejection in Renal Transplant Recipients

The clinical relevance of daily measurement of beta 2-microglobulin in serum and urine was evaluated in 49 patients undergoing renal transplantation. The changes in beta 2-microglobulin levels were compared to standard parameters for assessment of renal function. One hundred episodes of acute deterioration of renal function, clinically diagnosed as rejection, were analyzed retrospectively: (1) In 18 episodes renal malfunction did not respond to methylprednisone but improved immediately upon dose reduction of ciclosporin A, thus indicating a nephrotoxic effect of the drug. In these cases a mean increase of beta 2-microglobulin in urine as high as 7.9 mg/l was observed while serum values decreased. (2) Fifty episodes of apparent rejection (responsive to steroids) were preceded by a 3-day lasting continuous rise of beta 2-microglobulin in serum of up to 3.6 mg/l as a mean with only a moderate elevation in urine. (3) In 13 episodes antirejection treatment could have been avoided as continuously declining laboratory parameters indicated spontaneous improvement of renal function. We conclude that parallel determination of beta 2-microglobulin in serum and urine allows to differentiate between ciclosporin A nephrotoxicity and rejection in 91% of the cases.

Elevated plasma fibronectin levels in nephrotic syndrome

SummaryIn nine patients with nephrotic syndrome the behaviour of plasma fibronectin was studied. Of nine patients seven showed elevated plasma fibronectin levels while the plasma fibrinogen level was increased in eight of the nine investigated patients. A positive correlation was found between plasma fibronectin levels and fibrinogen (P<0.01), cholesterol (P<0.01) and proteinuria (P<0.05). The results indicate that elevated plasma fibronectin levels could be an additional factor responsible for hypercoagulability in nephrotic syndrome.

Die intraerythrozytäre GOT-Aktivität bei Urämie und ihr Verhalten unter Pyridoxinapplikation

A significant decrease of the glutamic oxalacetic transaminase activity of erythrocytes (EGOT) was found in patients on regular dialysis treatment. When pyridoxal-5-phosphate, the active metabolite of vitamin B6, was added to the samples, EGOT activity increased in dialysis patients and in normals, but the activity obtained after stimulation was not as high in haemodialyzed patients as in volunteers. In normals and in patients under pyridoxine treatment the EGOT activity was significantly higher when compared to the corresponding groups without vitamin B6 administration, the EGOT activity depending on duration of pyridoxine treatment.SummaryA significant decrease of the glutamic oxalacetic transaminase activity of erythrocytes (EGOT) was found in patients on regular dialysis treatment. When pyridoxal-5-phosphate, the active metabolite of vitamin B6, was added to the samples, EGOT activity increased in dialysis patients and in normals, but the activity obtained after stimulation was not as high in haemodialyzed patients as in volunteers. In normals and in patients under pyridoxine treatment the EGOT activity was significantly higher when compared to the corresponding groups without vitamin B6 administration, the EGOT activity depending on duration of pyridoxine treatment.

Kupfer, Eisen und deren Trägerproteine (Coeruloplasmin und Transferrin) im Plasma chronisch dialysierter Patienten

SummaryIn 11 chronic dialysis patients the influence of dialysis treatment on copper, iron, ceruloplasmin and transferrin concentrations in the plasma was investigated. Copper and iron were determined photometrically, ceruloplasmin and transferrin by the radial immunodiffusion method. The mean pre-dialysis values of copper and ceruloplasmin were within the upper limit of normal, probably as a possible consequence of copper overloading when using copper-containing dialysis membranes. Low transferrin levels, low latent iron binding capacity and high iron saturation could be due to transfusion haemosiderosis and catabolism. In spite of a considerable copper release from the membrane to the plasma during the first hour of dialysis, there was no significant change in the plasma copper concentration at the end of the dialysis. Ceruloplasmin, transferrin and iron showed a fall in plasma concentrations during dialysis. It can be assumed that lower molecular fractions of ceruloplasmin and transferrin are dialysable.ZusammenfassungBei 11 chronischen Dialysepatienten wurden die Plasmakonzentrationen von Kupfer, Eisen und deren Trägerproteine (Coeruloplasmin und Transferrin) und der Einfluß der Dialysebehandlung auf diese Parameter untersucht. Kupfer und Eisen wurden photometrisch, Coeruloplasmin und Transferrin nach der Radialimmunodiffusionsmethode bestimmt. Der mittlere Kupfer- und Coeruloplasminspiegel lagen im oberen Bereiche der Norm, möglicherweise als Ausdruck einer chronischen Kupferüberladung durch die Verwendung kupferhältiger Dialysatoren. Niedriges Transferrin im Plasma, vermindertes ungesättigtes Eisenbindungsvermögen und erhöhte prozentuelle Eisensättigung waren mit einer Transfusionshämosiderose und einer katabolen Stoffwechsellage in Einklang zu bringen. Trotz einer ausgeprägten Kupferabgabe von der Membran an das Patientenblut in der ersten Dialysestunde kam es zu keiner Änderung des Kupferspiegels im Plasma gegen Ende der Dialyse. Coeruloplasmin, Transferrin und Eisen zeigten einen Konzentrationsabfall im Plasma während der Dialysen. Es wird angenommen, daß niedermolekulare Untereinheiten von Coeruloplasmin und Transferrin dialysabel sind.

The effect of histamine2 and muscarine receptor antagonists on plasma levels of parathyroid hormone and calcitonin

SummaryLong-term administration of cimetidine, a histamine2 receptor antagonist, has been reported to normalize elevated parathyroid hormone (PTH) concentrations in patients with secondary [1] and primary hyperparathyroidism [2] and even to improve the clinical symptoms. We have compared the effect of cimetidine and pirenzepine on PTH and calcitonin (CT) plasma levels in a short-term trial on patients with secondary hyperparathyroidism. After cimetidine a significant effect on PTH was seen within 30 min lasting 30 min and after pirenzepine, within 60 min and lasting 60 min. The effect on CT was only significant after cimetidine.ZusammenfassungIn letzter Zeit wurde über den Langzeiteffekt von Cimetidin, eines Histamin2-Rezeptorantagonisten, erhöhte PTH Serumkonzentrationen beim sekundären1 und primären Hyperparathyroidismus2 zu senken, berichtet. Dabei wurde auch eine Verbesserung des klinischen Bildes beobachtet. Wir haben die Wirkung von Cimetidin und Pirenzepin auf den Plasmaspiegel von PTH und CT bei Patienten mit sekundären Hyperparathyroidismus in einem Kurzzeitversuch geprüft. Eine signifikante Senkung der PTH Serumkonzentration wurde mit Cimetidin nach 30 min für die Dauer von 30 min gesehen. Mit Pirenzepin zeigte sich erst 60 min nach der Infusion ein 60 min lange anhaltender signifikanter Abfall der PTH Serumkonzentration. Der Calcitonin Serumspiegel war nur mit Cimetidin signifikant senkbar.

Alpha-1-Antitrypsin und Fibrinogenspiegel bei chronischer Niereninsuffizienz und nach Nierentransplantation

SummaryIn ten non dialyzed patients with chronic renal failure, 18 patients on regular dialysis treatment and 70 renal transplant recipients alpha-1-antitrypsin and fibrinogen levels were investigated. Alpha-1-antitrypsin and fibrinogen concentrations were highest in dialyzed patients with values of 314 ± 98 and 485 ± 127 mg/dl respectively. In renal transplant recipients a significant positive correlation between alpha-1-antitrypsin and fibrinogen concentration was found (p < 0.001). High alpha-1-antitrypsin and fibrinogen levels seem to be a possible consequence of reactive processes due to underlying disease or complications. Our results seem to indicate that both α1-antitrypsin and fibrinogen can be classified as “acute phase protein”.ZusammenfassungAlpha-1-Antitrypsin und Fibrinogenspiegel wurden bei zehn nichtdialysierten Patienten mit chronischer Niereninsuffizienz, 18 Dialysepatienten und 70 Nierentransplantierten untersucht. Die höchsten α1-Antitrypsin- und Fibrinogenwerte boten Dialysepatienten mit 314 ± 98 bzw. 485 ± 127 mg/dl. Bei nierentransplantierten Patienten bestand eine signifikante positive Korrelation zwischen α1-Antitrypsin und Fibrinogenkonzentrationen (p < 0,001).Hohe α1-Antitrypsin und Fibrinogenwerte könnten wahrscheinlich Ausdruck von reaktiven Prozessen im Rahmen der Grunderkrankung oder Komplikationen sein. Die Untersuchungsergebnisse scheinen zu beweisen, daß sowohl α1-Antitrypsin als auch Fibrinogen als „Akutphasenproteine“ angesehen werden können.