Nephrol Dial Transplant (1992): Letters
368 Tabte 1. Comparison between the two assays in normal subjects and dialysed patients Normal subjects
Dialysed patients (i = 45)
Ep RIA (mUI/ml)
20.4 + 6.5
37.0 ±27 0
Ep IRMA (mUI/ml)
8.3±2.9
Correlation coefficient
r = 0.594 /••cO.OOOOl
1
•/> =
O
-3~^±,,.7 r = 0.930 /> subjects (2.99 ±0.44 umol 1 versus 2.35±0.59 umol 1). No changes could be detected during haemodialysis (2.99±0.44 umol 1 versus 2.85±0.65 umol I). No correlation between erythrocyte and whole blood SOD activities and plasma MDA was found. Chronic renal failure is characterized by a complex pathology including metabolic, cardiovascular, and anaemic complications. Increased oxygen radical production and or insufficient antioxidant system can contribute at least in part to the pathogenesis. The present study confirms the concept of oxidative stress in uraemic patients. At present, no clear explanation for the observed reduced SOD activities can be given. One possible causative moment is the ineffective erythropoesis within the bone marrow. Aluminium overload should also be considered since it is known that aluminium inhibits SOD activity [6]. University of Rostock Institute of Clinical Chemistry Department of Internal Medicine Rostock, Germany
M. Steiner K. von Appen H. Klinkmann B. Ernst
1. Shainkin-Kestenbaum R, Caruso C, Berlyne GM. Reduced superoxide dismutase activity in erythrocytes of dialysis patients: a possible factor in the etiology of uremic anemia. Nephron 1990; 55: 251-253 2. Richard MJ, Arnaud J, Jurkovitz C et al. Trace elements and lipid peroxidation abnormalities in patients with chronic renal failure. Nephron 1991; 57: 10-15 3. Trznadel K, Pawlicki L, Kedziora J, Luciak M, Blaszczyk J, Buczynski A. Superoxide anion generation, erythrocyte superoxide dismutase activity, and lipid peroxidation during hemoperfusion and hemodialysis in chronic uremic patients. Free Radic Biol Med 1989; 6: 393-397 4. Buege JA, Aust SD. Microsomal lipid peroxidation. Meih Enzymol 1978; 52: 302-310 5. Sun Y, Oberley LW, Li Y. A simple method for clinical assay of superoxide dismutase. Clin Chem 1988; 34: 497-500 6. Shainkin-Kestenbaum R, Adler AJ, Berlyne GM, Caruso G. Effect of aluminium on superoxide dismutase. Clin Sci 1989; 77: 463-466
Utility of bone densimetry in haemodialysis Sir, Renal osteodystrophy is a pathology of great significance for haemodialysis patients, although limited diagnostic techniques still pose a problem in both diagnosis and control of the disease [1,2]. The development of precise and non-invasive techniques, i.e. the densimetric measurement of the bone mass by means of photon beam adsorption, has given new perspectives to its study [3]. Because current experience is poor, and both calcium and aluminium deposits arc measured, results obtained in this way should be considered with caution r4].
Our study involved 51 patients, 33 male and 18 female, within a programme of intermittent haemodialysis with Cuprophan (45.1%) or cellulose acetate (54.9%) three sessions weekly, 4 h each, for an average dialysis period of 45 ±35 months. All patients received aluminium hydroxide, with 40 patients also receding an extra administration of calcitriol. Serum calcium, phosphorus, magnesium, PTH, and aluminium concentrations were measured. The mineralized bone mass was studied b> means of a double photon densimeter applied to the lumbar column (L2~L4) in a lateral position, as the varying quantities of mineral in the trabecular bone were considered to be a more sensitive indicator of the cortical component [5], and it was hoped that this position would reveal much more realistic values if the superposition of other calcified elements (arteries, ligaments etc.) was ignored. Average values of bone density were 0.65 ± 15 g cm2, compared with current estimated values of 0.8 g/cm2 [6]. Significant linear relations were found between density and age (/>< 0.001), time, and aluminium (/>
368 Tabte 1. Comparison between the two assays in normal subjects and dialysed patients Normal subjects
Dialysed patients (i = 45)
Ep RIA (mUI/ml)
20.4 + 6.5
37.0 ±27 0
Ep IRMA (mUI/ml)
8.3±2.9
Correlation coefficient
r = 0.594 /••cO.OOOOl
1
•/> =
O
-3~^±,,.7 r = 0.930 /> subjects (2.99 ±0.44 umol 1 versus 2.35±0.59 umol 1). No changes could be detected during haemodialysis (2.99±0.44 umol 1 versus 2.85±0.65 umol I). No correlation between erythrocyte and whole blood SOD activities and plasma MDA was found. Chronic renal failure is characterized by a complex pathology including metabolic, cardiovascular, and anaemic complications. Increased oxygen radical production and or insufficient antioxidant system can contribute at least in part to the pathogenesis. The present study confirms the concept of oxidative stress in uraemic patients. At present, no clear explanation for the observed reduced SOD activities can be given. One possible causative moment is the ineffective erythropoesis within the bone marrow. Aluminium overload should also be considered since it is known that aluminium inhibits SOD activity [6]. University of Rostock Institute of Clinical Chemistry Department of Internal Medicine Rostock, Germany
M. Steiner K. von Appen H. Klinkmann B. Ernst
1. Shainkin-Kestenbaum R, Caruso C, Berlyne GM. Reduced superoxide dismutase activity in erythrocytes of dialysis patients: a possible factor in the etiology of uremic anemia. Nephron 1990; 55: 251-253 2. Richard MJ, Arnaud J, Jurkovitz C et al. Trace elements and lipid peroxidation abnormalities in patients with chronic renal failure. Nephron 1991; 57: 10-15 3. Trznadel K, Pawlicki L, Kedziora J, Luciak M, Blaszczyk J, Buczynski A. Superoxide anion generation, erythrocyte superoxide dismutase activity, and lipid peroxidation during hemoperfusion and hemodialysis in chronic uremic patients. Free Radic Biol Med 1989; 6: 393-397 4. Buege JA, Aust SD. Microsomal lipid peroxidation. Meih Enzymol 1978; 52: 302-310 5. Sun Y, Oberley LW, Li Y. A simple method for clinical assay of superoxide dismutase. Clin Chem 1988; 34: 497-500 6. Shainkin-Kestenbaum R, Adler AJ, Berlyne GM, Caruso G. Effect of aluminium on superoxide dismutase. Clin Sci 1989; 77: 463-466
Utility of bone densimetry in haemodialysis Sir, Renal osteodystrophy is a pathology of great significance for haemodialysis patients, although limited diagnostic techniques still pose a problem in both diagnosis and control of the disease [1,2]. The development of precise and non-invasive techniques, i.e. the densimetric measurement of the bone mass by means of photon beam adsorption, has given new perspectives to its study [3]. Because current experience is poor, and both calcium and aluminium deposits arc measured, results obtained in this way should be considered with caution r4].
Our study involved 51 patients, 33 male and 18 female, within a programme of intermittent haemodialysis with Cuprophan (45.1%) or cellulose acetate (54.9%) three sessions weekly, 4 h each, for an average dialysis period of 45 ±35 months. All patients received aluminium hydroxide, with 40 patients also receding an extra administration of calcitriol. Serum calcium, phosphorus, magnesium, PTH, and aluminium concentrations were measured. The mineralized bone mass was studied b> means of a double photon densimeter applied to the lumbar column (L2~L4) in a lateral position, as the varying quantities of mineral in the trabecular bone were considered to be a more sensitive indicator of the cortical component [5], and it was hoped that this position would reveal much more realistic values if the superposition of other calcified elements (arteries, ligaments etc.) was ignored. Average values of bone density were 0.65 ± 15 g cm2, compared with current estimated values of 0.8 g/cm2 [6]. Significant linear relations were found between density and age (/>< 0.001), time, and aluminium (/>
