Amino acid content of erythrocytes in uremia.

The amino acid content of plasma and erythrocytes in patients with severe renal failure (serum creatinine less than 8 mg/100 ml) treated with selective low-protein diets, in patients on regular hemodialysis, and in a control group of healthy subjects were studied. Most amino acids in erythrocytes of the patients showed the same changes as in plasma with the exception of histidine, serine, and alanine. In spite of low histidine plasma levels, the erythrocytes level is increased as compared with healthy controls. In uremic patients the plasma serine was constantly reduced whereas the serine content of the erythrocytes did not differ from healthy controls. Alanine concentrations in the erythrocytes of uremic patients were increased in spite of normal alanine plasma levels. This finding may be due to the increased glycolytic ratio of red cells from uremic subjects delivering more pyruvate for transmination to alanine. In the control group the cysteine content of erythrocytes was decreased with a gradient between plasma and erythrocytes of 3.5:1. The same gradient could be observed in uremic patients in spite of the elevation in their plasma cysteine levels by a factor of 2.7 compared with controls. The low cysteine levels in erythrocytes may be due to loss of cysteine for glutathione synthesis in red cells. High glutathione levels in the erythrocytes of uremic patients support this hypothesis.

Toxoplasmosis after renal transplantation.

Infection is the main cause of death following renal transplantation. In the literature 7 fatal cases of toxoplasmosis following renal transplantation have been described. In the present papers a case of reactivated toxoplasmosis is presented where the patient survived. Fortuitous withdrawal of therapy and transplant nephrectomy may have been responsible for the patient's survival. The problems of diagnosis of toxoplasmosis following renal transplantation are discussed. Early diagnosis is vitally important as successful treatment of toxoplasmosis with pyrimethamine and sulfonamides in patients receiving immunosuppressive therapy has been reported. It is emphasised that reaction of toxoplasmosis should always be considered in patients with fever of unknown origin and cerebral symptoms.

[Complications and lethality after kidney grafts (author's transl)]. / Komplikationen und Letalität nach Nierentransplantationen.

Similarly good survival rates were obtained in 113 patients with kidneys transplanted from deceased persons as with patients on home dialysis. The retrospective study showed that fatal complications were not predominantly caused by septic diseases running fateful courses under immunosuppression, but by risk factors which were not recognized soon enough or were incorrectly treated. In our opinion, with careful preparation and supervision of these patients, even in the still unsatisfactory state of immunosuppressive therapy, the possibility exists of carrying out renal grafting without increased risk of mortality compared with dialysis treatment.

[Anemia in terminal kidney insufficiency: ferrokinetics, erythrocyte survival times and erythrocyte enzymes in chronic dialysis patients]. / Anämie bei terminaler Niereninsuffizienz Ferrokinetik, Erythrozyten-Uberlebenszeit und Erythrozytenenzyme bei chronisch dialysierten Patienten

Radio-iron utilization was nearly normal in these patients, only bilateral nephrectomized patients showed a reduced radio-iron utilization. Red blood half-life span was shortened in all patients, well corresponding to the degree of anemia. Parameters of erythropoesis like plasma iron clearance, bone marrow transit time, erythron iron turnover, non erythron iron turnover and hemolysis iron turnover failed to quantitate disorders of red blood cell regeneration in these patients. No defect in red blood cell enzyme activity could be demonstrated. Enzymes of glycolysis were increased corresponding to the reduced erythrocyte half-life span.

Amino acid and protein intake in RDT patients. A nutritional and biochemical analysis.

In 40 unselected RDT patients (20 center and 20 home dialysis patients) the intake of nutrients was measured using the precise weighing method of Wirths [1969]. The protein intake was found to be 0.97 plus or minus 0.19 g/kg predialysis body weight, the calorie intake 32.3 plus or minus 6.4 cal/kg. Two thirds (0.65 plus or minus 0.15 g/kg) of the protein consisted of high biological value protein. Despite the fact that according to current recommendations the protein intake should have been adequate, signs of protein malnutrition were found. The mean serum concentrations of total protein, transferrin and valine and the ratio of essential amino acids to nonessential amino acids (EAA/NEAA) were significantly lower than in normal subjects and the glycine level was elevated. Histidine levels were normal indicating that the histidine intake measured at 1.75 plus or minus 0.47 g/day appeared adequate under these conditions. Phenylalanine levels were elevated indicating a blocking of 4-hydroxylase leading to low tyrosine levels. A possible reason for these findings may be that the protein requirements of the RDT patient over a long period of time are higher than those found experimentally in short term studies. An inadequate calorie intake could not be excluded. Additionally a dialysis dependent pathologic variation of the daily intake of nutrients may be responsible for the disturbed nutritional status. In connection with this, three distinct types of intake variation can be described: A stable type in which the variation in the daily protein and calorie intake does not differ by more than 20% from a daily mean value, an unstable type I with significantly lower intake on the day of dialysis and an unstable type II with a significantly higher intake on the day of dialysis. Signs of protein malnutrition occurred significantly more frequently in the unstable groups.

Histidine and iron supplementation in dialysis and pre-dialysis patients.

Chronic renal failure (CRF) patients treated with histidine alone did not show any effect with respect to anaemia or protein metabolism, despite a rise in serum histidine levels. Beneficial effect of iron with regards to anaemia and protein metabolism was seen in CRF patients treated with iron alone or in combination with histidine. Patients with combination therapy showed accelerated improvement of anaemia in comparison with patients treated with iron alone. In RDT patients, who underwent basic treatment with parenteral iron, histidine failed to show any effect with regards to anaemia, despite significantly lowered serum histidine levels. But under histidine treatment a significant rise of transferrin levels occurred in RDT patients, so that histidine must be considered as a limiting factor in protein metabolism in these cases. Histidine requirements of RDT patients are more than 1-2 g/day, and are higher than the requirements of patients conservatively treated.

Proteinuria as diagnostic marker after human kidney transplantation.

Molecular weight analyses of urinary proteins in 34 patients following cadaveric kidney transplantation were performed by SDS-PAA-electrophoresis in order to diagnose transplant complications. A micromolecular 'tubular' proteinuria (mw 70-10,000) was found in all post-operative urines. Later on during clinically normal periods the patients exhibited an unphysiological proteinuria of mw 70-40,000. Recurrence of tubular proteinuria was associated with rejection episodes and acute kidney failure. Twelve patients developed a macromolecular glomerular proteinuria (mw greater than 60,000), caused by recurrent glomerulonephritis, glomerular rejection disease or renal vein thrombosis. Steroid treatment reduced the glomerular permeability for macromolecules above mw 65,000.