Plasma Exchange or Immunoadsorption in Patients with Rapidly Progressive Crescentic Glomerulonephritis a Swedish Multi-Center Study

A therapeutic removal of antibodies may be achieved by immunoadsorption (IA) or by plasma exchange (PE). The aim of this prospective randomised study was to compare the efficacy of these different techniques with regard to treatment of patients with rapidly progressive glomerulonephritis (RPG) having at least 50% crescents. Forty-four patients with a RPG were included for treatment either by IA or PE (with albumin as substitution for removed plasma). All patients were additionally treated with immunosuppression. A median of 6 sessions of PEs were performed in 23 patients compared with 6 IAs in 21 patients. Goodpasture's syndrome (GP) was present in 6 patients (PE 3, IA 3). All of them started and ended in dialysis, two died. Among the remaining 38 patients (26 men, 12 women) 87% had antibodies to ANCA. Creatinine clearance for PE versus IA were at a median at start 17.1 and 19.8 ml/min, and at 6 months 49 and 49 ml/min, respectively. At 6 months 7 of 10 patients did not need dialysis (remaining: IA 0/5 and PE 2/5, n.s.). The extent of improvement did not differ between the groups. Three patients died during the observation period of 6 months (IA 2; PE 1, on HD). Although no difference was found between the IA or the PE group this study shows that the protocol used was associated with an improved renal function in most patients (except for Goodpasture's syndrome) whereas 70% of them could leave the dialysis program.

Adherence of Blood Cells to Dialyzer Membranes as a Measure of Biocompatibility

Cell adherence to plate dialyzer membranes was analysed at the end of 4 hours of dialysis. Three types of membranes were examined: Cuprophan® Hemophan® and Gambrane®, (a polycarbonate membrane). The membranes were mounted in dialyzers that contained 23 layers of one membrane type and one layer of each of the two other. Less leukocytes adhered to the Pc than to the Cu and He membranes. Transient initial complement activation during dialysis, which was considerably lower with dialysers containing mainly Pc membrane, was not correlated to adherence of cells to the membranes. Instead flow geometry is proposed as the main factor determining the adherence. Contrary to what has been earlier suggested, we think that leukocyte adherence is not a very suitable measure of membrane biocompatibility. The reason is that the influence of membrane surface-chemical factors can not be separated from mechanical factors due to the design of the device.

Long-term follow-up of reflux nephropathy in adults with vesicoureteral reflux – radiological and pathoanatomical analysis

Purpose: To study the long-term development of urographic renal morphology in adults with vesicoureteral reflux, to investigate the relationship between renal damage and reflux grade, and to analyse the association between the long-term urographic outcome and the occurrence of acute pyelonephritis and reflux during follow-up. The purpose was also to try to distinguish between acquired and developmental renal damage, based on analyses of renal histological specimens and urographic features, and to analyse associated congenital urogenital abnormalities and family history of reflux, reflux nephropathy, urological malformation or death from end-stage renal disease.

Material and Methods: Renal damage was identified in 100 (83 women) of 115 adults, selected because of documented reflux. Eighty-seven patients had two urographies done (median interval 14.3 years). The extent and progression of renal damage were assessed and features of developmental renal damage were determined. Histological renal specimens were available in 23 patients with renal damage.

Results and Conclusions: The extent of renal damage correlated positively with the severity of reflux. No renal damage developed during the follow-up in 45 previously undamaged kidneys and progression of renal damage was rare (4 of 120 previously damaged kidneys), despite persisting reflux in half of the cases and episodes of acute pyelonephritis during follow-up. Thus, repeated renal imaging is rarely justified in adults with reflux nephropathy. Histological examination showed "chronic pyelonephritis" in all 23 cases and co-existing renal dysplasia in 1 case. The detailed urographic analysis did not reveal support for developmental renal damage. High frequencies of associated congenital urogenital abnormalities and of a positive family history were found. Thus, congenital and/or hereditary factors cannot be discarded as background factors for the development of renal damage.

Urinary beta-hexosaminidase excretion in polycystic kidney disease

The urinary excretion of beta-hexosaminidase in relation to creatinine was studied during one year in 30 consecutive patients with polycystic kidney disease (S-creatinine 75-1 000 micro mol/l) and 30 healthy controls. The excretion of beta-hexosaminidase was significantly increased in the patients and was positively correlated to S-creatinine and to the relative increase in S-creatinine during the year of the study. No correlation was found between the enzyme excretion and age, mean blood pressure, number of antihypertensive drugs, proteinuria or pyuria. A significant rise in beta-hexosaminidase excretion was observed in two patients with acute cyst bleeding and/or kidney infarction.

Serum level of complement factor D in systemic lupus erythematosus--an indicator of glomerular filtration rate

Serum levels of complement factor D, a low molecular weight (LMW) protein, were high and inversely correlated with glomerular filtration rate (GFR) determined in 19 patients with lupus glomerulonephritis (LGN). Factor D was significantly closer correlated with S-creatinine than were two other LMW proteins, beta 2-microglobulin and gamma-trace in 22 LGN patients. Close correlations between each of the LMW proteins and S-creatinine were found in patients with a non-inflammatory disorder, polycystic kidney disease. Slightly increased beta 2-microglobulin concentrations were found in 15 of 20 systemic lupus erythematosus (SLE) patients without renal involvement, while factor D and gamma-trace showed normal values in most of these patients. The findings imply that serum concentrations of complement factor D in SLE are mainly determined by the GFR.

The effect of D,L-carnitine supplementation on muscle metabolism, neuropathy, cardiac and hepatic function in hemodialysis patients. A pilot study

Three patients on regular hemodialysis treatment were perorally supplemented with D.L-carnitine, 900 mg/d, during four weeks. Before treatment, muscle carnitine concentrations were low and the patients showed signs of hypometabolism in skeletal muscle, cardiomyopathy, impaired hepatic function and a moderate hyperlipoproteinemia. After treatment, the skeletal muscle metabolism normalized. The results further indicate improvement of the cardiac and hepatic function and of the neuropathy on the sensory side. No improvement was found, however, in plasma lipoprotein pattern or in variables reflecting plasma lipid transport (lipoprotein lipase activity and intravenous fat tolerance).

Immunosuppression and the additive effect of plasma exchange in treatment of rapidly progressive glomerulonephritis

Attempts were made to evaluate the separate effect on kidney function of immunosuppressive treatment (IS) and plasma exchange (PE) in 27 patients with rapidly progressive glomerulonephritis (RPGN). Twenty-four of the patients were treated with PE. Initial IS was supplemented with PE within 6-12 days in 5 patients, and after at least 14 days in 13. Because of suspected septicemia, 2 patients were first treated with PE, and IS was not initiated until the possibility of septicemia had been excluded. In 4 severely ill patients wih rapid clinical deterioration, both treatments were started simultaneously. Twenty patients improved during one or both treatments, 4 with IS alone, 2 with IS and doubtfully with PE, 3 with IS and probably also with PE, 5 both with IS and PE and one with PE alone. In 5 patients the individual effects of IS and PE could not be evaluated. In another 2 patients the combined treatment seemed to influence the course favourably. In the remaining 7 patients the effect of the treatment was doubtful or nil. Two further patients with Goodpasture's syndrome were treated. They were admitted late, and both kinds of treatment were instituted simultaneously. One of them died in respiratory insufficiency, the other remained oliguric while the pulmonary changes faded. Thus, PE added a positive effect to IS in several patients with RPGN. The treatment had few and mostly mild side-effects.

Serum concentration of cystatin C, factor D and beta 2-microglobulin as a measure of glomerular filtration rate

Serum concentrations of creatinine and of the three low molecular weight (LMW) proteins cystatin C, factor D of the complement system and beta 2-microglobulin were measured in 135 consecutive patients, whose glomerular filtration rates (GFR) were determined by Cr-EDTA. In the total patient series, the reciprocals of S-creatinine and S-cystatin C were numerically and, in males, significantly more closely correlated to GFR than the reciprocals of S-factor D. The reciprocals of beta 2-microglobulin showed a weaker correlation to GFR than those of the other three substances. The calculated glomerular elimination rates of creatinine, cystatin C and factor D were normally distributed, in contrast to those of beta 2-microglobulin. According to data presented so far, cystatin C seems to be the LMW protein of first choice when GFR is to be estimated by measuring the plasma concentration of a LMW protein.

Successful treatment of hemolytic uremic syndrome and thrombotic thrombocytopenic purpura with fresh frozen plasma and plasma exchange

Four patients with hemolytic uremic syndrome (HUS) and seven with thrombotic thrombocytopenic purpura (TTP) were treated with infusions of fresh frozen plasma (FFP). In one patient with HUS and five patients with TTP this treatment was combined with plasma exchange (PE). The additional treatment varied; corticosteroids, antiplatelet drugs, heparin and blood exchange. All but one patient recovered completely in spite of severe illness with uremia, oliguria and/or cerebral symptoms during the acute phase. The results were surprisingly good in comparison with other published series. The success must in the first place be attributed to early diagnosis and to the infusions of FFP. PE seemed to potentiate the effect of FFP.

Long-term follow-up of reflux nephropathy in adults with vesicoureteral reflux--radiological and pathoanatomical analysis

PURPOSE

To study the long-term development of urographic renal morphology in adults with vesicoureteral reflux, to investigate the relationship between renal damage and reflux grade, and to analyse the association between the long-term urographic outcome and the occurrence of acute pyelonephritis and reflux during follow-up. The purpose was also to try to distinguish between acquired and developmental renal damage, based on analyses of renal histological specimens and urographic features, and to analyse associated congenital urogenital abnormalities and family history of reflux, reflux nephropathy, urological malformation or death from end-stage renal disease.

MATERIAL AND METHODS

Renal damage was identified in 100 (83 women) of 115 adults, selected because of documented reflux. Eighty-seven patients had two urographies done (median interval 14.3 years). The extent and progression of renal damage were assessed and features of developmental renal damage were determined. Histological renal specimens were available in 23 patients with renal damage.

RESULTS AND CONCLUSIONS

The extent of renal damage correlated positively with the severity of reflux. No renal damage developed during the follow-up in 45 previously undamaged kidneys and progression of renal damage was rare (4 of 120 previously damaged kidneys), despite persisting reflux in half of the cases and episodes of acute pyelonephritis during follow-up. Thus, repeated renal imaging is rarely justified in adults with reflux nephropathy. Histological examination showed "chronic pyelonephritis" in all 23 cases and co-existing renal dysplasia in 1 case. The detailed urographic analysis did not reveal support for developmental renal damage. High frequencies of associated congenital urogenital abnormalities and of a positive family history were found. Thus, congenital and/or hereditary factors cannot be discarded as background factors for the development of renal damage.

Conservative treatment and anti-reflux surgery in adults with vesico-ureteral reflux: effect on urinary-tract infections, renal function and loin pain in a long-term follow-up study

STUDY PURPOSE

To investigate the long-term effects in adults of conservative treatment and anti-reflux surgery for vesico-ureteral reflux on urinary-tract infections, renal function, and loin pain.

METHODS

Of 115 adult patients with vesico-ureteral reflux diagnosed between 1968 and 1984, conservative treatment was given to 46 patients (36 women) and anti-reflux surgery was performed in 57 patients (52 women). The remaining 12 patients underwent nephrectomy or heminephrectomy and were excluded from the study. The anti-reflux surgical methods used were the Politano-Leadbetter procedure in 44 patients (73 ureters) and the Hutch procedure in 19 patients (25 ureters). Six of these patients were operated on with both methods.

RESULTS

The frequency of acute pyelonephritis was significantly reduced after anti-reflux surgery (P < 0.0001) as well as after diagnosis of vesico-ureteral reflux in the group given conservative treatment (P or < 0.001). The frequency of lower-urinary-tract infections was not altered in either group. Surgery had no effect on significant albuminuria (Albustix > or = 2+) or on progressive renal functional deterioration. Forty-three patients reported recurrent loin pain at the time of diagnosis or anti-reflux surgery. Only one of the 12 patients in the conservative group, compared with 29 of the 31 patients in the anti-reflux surgery group, obtained relief from loin pain during the follow-up. Nine patients in the anti-reflux surgery group reported restitution of reduced general well-being after surgery. These patients had experienced weariness and/or headache before surgery. Vesico-ureteral reflux was eliminated more frequently (P < 0.01) in the patients operated on by the Politano-Leadbetter procedure (94%) than in those operated on by the Hutch procedure (68%).

CONCLUSIONS

Loin pain is common in adults with vesico-ureteral reflux and is effectively eliminated by anti-reflux surgery. Anti-reflux surgery should be considered in adults with vesico-ureteral reflux and very frequent acute pyelonephritic attacks only if conservative treatment has failed to alleviate these symptoms. Anti-reflux surgery is not indicated with the aim of arresting renal functional deterioration.

Heparin and vasoactive peptides in hemodialysis patients

Plasma concentrations of vasoactive peptides have been reported to be influenced by various procedural features of hemodialysis (HD), such as ultrafiltration and isovolemic diffusion, dialysate buffer and dialysate temperature, but also by sham HD thus reflecting an effect of the extracorporeal circulation per se. In the present study the effect of heparin administration was investigated in 9 stable HD patients, and compared with that of saline. Blood samples were taken from the arteriovenous fistula before and 45 min after the administration of heparin or saline. After an interval of 2 weeks, the procedure was repeated with the exception that the patients who received heparin on the first occasion were given saline and vice versa. Plasma concentrations of the vasoactive peptides were measured by radioimmunoassay. Regardless of whether heparin was given or not, the plasma concentrations of the vasodilators atrial natriuretic peptide, beta-endorphin and vasoactive intestinal peptide did not change, nor did the concentration of the vasoconstrictor neuropeptide Y. The plasma motilin concentration decreased significantly when heparin was given, and that of substance P increased, both these peptides being vasodilators. Mean arterial blood pressure decreased regardless of whether heparin was given or not, and no difference between the two regimens was noted. Heart rate was unchanged with both regimens. To sum up, administration of heparin but not of saline affected the plasma concentrations of motilin and substance P. However, the decrease in blood pressure during the procedure seemed not to be related to the changes in these peptides, as it also occurred in the absence of heparin.

Development of a urea concentration gradient between muscle interstitium and plasma during hemodialysis

In this pilot study, muscle interstitial urea concentrations during hemodialysis (HD) were determined with a microdialysis technique and the results were compared with plasma water urea concentrations. Three patients were investigated during a total of five treatments. Under predialysis steady-state conditions, no difference was observed. During treatment, the muscle interstitial urea concentration was on average 19% higher (range 13-28%, n=4) than the plasma urea concentration after 17+/-3 min, 29% higher (25-31%, n=3) after 53+/-10 min, 40% higher (26-50%, n=3) after 117+/-6 min, 31% higher (26-34%, n= 3) after 179+/-5 min, and 31% higher (27-36%, n=4) after 231+/-5 min. The gradient declined after the conclusion of HD, muscle interstitial concentrations being on average 16% (9-26%, n=4) higher than plasma urea concentrations 9+/-2 min after treatment, and 8% (6-10%, n=3) 25+/-3 min after treatment. Thus, a urea concentration gradient with a higher concentration in muscle interstitium than in plasma, developed during HD, and dissipated gradually after treatment. This is consistent with blood flow-dependent urea sequestration in muscle tissue, causing intercompartment disequilibrium of urea during HD, and its consequent redistribution after treatment contributing to postdialysis urea rebound.

Urine IgG2/IgG4-ratio indicates the significance of the charge selective properties of the glomerular capillary wall for the macromolecular transport in glomerular diseases

BACKGROUND

Alterations of the charge-selective properties of the glomerular capillary wall are important constituents of the pathogenesis of many glomerular diseases. Thus, differences in the degree of such changes could be of help in understanding the mechanisms governing the transport of macromolecules across the glomerular capillary wall.

METHODS

The ratio between urine concentrations of neutral IgG2 and negatively charged IgG4 (IgG2/IgG4-ratio) was measured in 150 proteinuric patients and 21 healthy controls. The patients were subdivided into seven biopsy verified diagnostic groups.

RESULTS

The study revealed decreased IgG2/ IgG4-ratio in membranous glomerulonephritis (0.57) compared to healthy controls (2.09) and to all other diagnosis groups; crescentic necrotizing glomerulonephritis (1.28), diffuse proliferative glomerulonephritis (1.10), IgA nephropathy (1.11), mesangial proliferative glomerulonephritis (1.55), minimal change nephropathy (1.00), and nephrosclerosis secondary to hypertension (1.06). Although not statistically significant, there was a tendency towards lower IgG2/IgG4-ratio values in all the studied glomerular diseases compared to healthy controls.

CONCLUSIONS

Since IgG is transported entirely through the large pores of the glomerular basement membrane decreased IgG2/IgG4-ratio implies that this pathway is strongly influenced by the charge-selective properties of the glomerular capillary wall. The conclusion that could be drawn from that is that the large pore radius must be discrete, in the order of 80-90 A, and thus not non-discriminatory to macromolecules as previously thought.

Plasma exchange or immunoadsorption in patients with rapidly progressive crescentic glomerulonephritis. A Swedish multi-center study

A therapeutic removal of antibodies may be achieved by immunoadsorption (IA) or by plasma exchange (PE). The aim of this prospective randomised study was to compare the efficacy of these different techniques with regard to treatment of patients with rapidly progressive glomerulonephritis (RPG) having at least 50% crescents. Forty-four patients with a RPG were included for treatment either by IA or PE (with albumin as substitution for removed plasma). All patients were additionally treated with immunosuppression. A median of 6 sessions of PEs were performed in 23 patients compared with 6 IAs in 21 patients. Goodpasture's syndrome (GP) was present in 6 patients (PE 3, IA 3). All of them started and ended in dialysis, two died. Among the remaining 38 patients (26 men, 12 women) 87% had antibodies to ANCA. Creatinine clearance for PE versus IA were at a median at start 17.1 and 19.8 ml/min, and at 6 months 49 and 49 ml/min, respectively. At 6 months 7 of 10 patients did not need dialysis (remaining: IA 0/5 and PE 2/5, n.s.). The extent of improvement did not differ between the groups. Three patients died during the observation period of 6 months (IA 2; PE 1, on HD). Although no difference was found between the IA or the PE group this study shows that the protocol used was associated with an improved renal function in most patients (except for Goodpasture's syndrome) whereas 70% of them could leave the dialysis program.

Proteinuria selectivity index based upon alpha 2-macroglobulin or IgM is superior to the IgG based index in differentiating glomerular diseases. Technical note

BACKGROUND

The proteinuria selectivity index (SI) may be used to describe changes of the glomerular permeability for macromolecules in glomerular diseases. Proteins the size of alpha 2-macroglobulin (alpha 2 M) or IgM cannot normally pass the glomerular barrier, whereas IgG can pass through the large pores of glomerular basement membrane. Comparison of the clearance of the three high-molecular-weight proteins to that of albumin may be useful in characterization and diagnosis of different glomerular diseases as well as in understanding of the permeability characteristics of the glomerular filter.

METHODS

Three types of SI, each calculated as a ratio of clearance of either IgG, alpha 2M or IgM to that of albumin, were measured in 199 proteinuric patients. The patients were subdivided into eight different biopsy-verified glomerular diseases.

RESULTS

Two diagnoses could be clearly distinguished using SI based on alpha 2M (alpha 2 M SI) or IgM (IgM SI). Both alpha 2M SI and IgM SI were significantly lower in minimal change nephropathy and higher in crescentic necrotizing glomerulonephritis than in all the other diagnoses. The SI based on IgG (IgG SI) was less useful in determining specific diagnoses, since patients with minimal change nephropathy could not be distinguished from those with other types of primary glomerulonephritis and patients with crescentic necrotizing glomerulonephritis did not differ from those with diabetic nephropathy.

CONCLUSIONS

The findings of this study indicate that alpha 2M SI and IgM SI are superior to IgG SI in characterization of glomerular disorders and might replace the IgG SI for this purpose.

Vesicoureteral reflux diagnosed in adulthood. Incidence of urinary tract infections, hypertension, proteinuria, back pain and renal calculi

STUDY PURPOSE

To determine the incidence of urinary tract infections, hypertension, back pain, and renal calculi in adult patients with vesicoureteral reflux and reflux nephropathy.

METHODS

A group of 115 patients (16-60 years of age, median 28 years) with vesicoureteral reflux, combined with reflux nephropathy in 101 patients, first detected between 1967 and 1984, was studied retrospectively. The group comprised 99 women and 16 men.

RESULTS

Symptoms and findings associated with the urinary tract preceded the diagnosis of vesicoureteral reflux by median 14 years (1-60 years). Intravenous pyelography preceded investigation with micturating cystography in 99 patients. Fifteen patients had no urinary tract infections, 17 patients had only lower urinary tract infections, and 83 patients had upper with or without lower urinary tract infections. Females had 12 times more lower and seven times more upper urinary tract infections than males, whereas males had impairment of renal function and proteinuria more often than females. Hypertension was present in 39 patients (34%) and five times more frequent in patients with bilateral than in those with unilateral reflux nephropathy. The median age at the first recording of hypertension was 33 years (16-60 years). Malignant hypertension was uncommon and occurred in two patients. An older group (> 45 years of age at presentation) of 19 patients showed a 90% incidence of hypertension compared with 23% in 96 patients in the younger group (< or = 45 years of age at presentation). Back pain of varying type and severity was present in 48 patients (42%). A total of 38 renal calculi was found in 21 (18%) patients, of whom 14 were completely asymptomatic.

CONCLUSIONS

The natural history of vesicoureteral reflux first detected in adulthood has shown a strikingly high incidence of urinary tract infections, arterial hypertension, back pain, and renal calculi.

Decreased excretion of glycosaminoglycans in patients with primary glomerular diseases

Urine glycosaminoglycans (GAG) concentrations were measured in 150 patients with primary glomerulonephritides: endocapillary glomerulonephritis, mesangial proliferative glomerulonephritis, IgA nephropathy, membranous glomerulonephritis and minimal change nephropathy, and in 63 healthy controls and 19 patients with diabetes nephropathy. The urine GAG to creatinine ratios (GCR) were significantly reduced (p < 0.01) in all the glomerulonephritides investigated (0.20 mg/mmol in endocapillary glomerulonephritis, 1.60 mg/mmol in mesangial proliferative glomerulonephritis, 1.74 mg/mmol in IgA nephropathy, 1.09 mg/mmol in membranous nephropathy, and 1.16 mg/mmol in minimal change nephropathy) compared to healthy controls (2.87 mg/mmol) but not compared to diabetes patients (1.17 mg/mmol). Also, the GCR in a group of 23 non-albuminuric glomerulonephritis patients (1.98 mg/mmol) was shown to be significantly decreased (p < 0.01) compared to healthy controls. Moreover, the GCR was significantly lower (p < 0.01) in endocapillary glomerulonephritis than in any of the other diseases studied. The GAG excretion per functioning glomerular area, calculated as fractional GAG excretion (FGE), was decreased in all the glomerulonephritides investigated compared to both healthy controls and diabetes nephropathy. The decreased GAG excretion in glomerulonephritides, obtained in the present study, might be a consequence of decreased synthesis or turnover of GAG in the functioning nephrons whereas the mechanisms for the reduced GAG excretion in diabetes nephropathy might be of a different nature. Urinary GAG excretion in this group of glomerular disorders and particularly in endocapillary glomerulonephritis, may lead to new approaches in non-invasive renal diagnostics and, particularly with regard to the differentiation of acute and chronic forms of glomerulonephritides.

Decreased excretion of urine glycosaminoglycans as marker in renal amyloidosis

BACKGROUND

The diagnosis of renal amyloidosis is normally established by kidney biopsy. In order to advance the determination of the diagnosis and the initiation of the therapy, fast and cheap, non-invasive diagnostic techniques are required.

METHODS

Urine excretion of glycosaminoglycans (GAG) was measured in 10 patients with AA amyloidosis and 5 patients with AL amyloidosis and compared to 25 controls with primary glomerular diseases and 22 healthy controls. The subjects with primary glomerular disease were matched with regard to their renal function and the degree of albuminuria.

RESULTS

The median urine GAG to creatinine ratio and the median fractional GAG excretion were significantly decreased (P < 0.05) in both AA amyloidosis (0.21 mg/mmol and 0.053 respectively) and AL amyloidosis (0.33 mg/mmol and 0.077 respectively) compared to control patients with primary glomerular disease (1.73 mg/mmol and 0.336 respectively) and healthy controls (2.67 mg/mmol and 0.226 respectively). The urine GAG to creatinine ratio did not correlate to age, sex, serum creatinine, urine albumin, or to the plasma levels of acute phase proteins.

CONCLUSIONS

The decreased GAG excretion in renal amyloidosis is probably caused both by diminished number of functioning nephrons, decreased GAG synthesis in functioning glomeruli, and the trapping of GAG by amyloid fibrils. Urinary GAG excretion may serve as an independent marker of renal amyloidosis. It may be used in diagnostic work-up of renal amyloidosis in patients with glomerular diseases and in screening of amyloidosis in patients with chronic inflammatory disorders, with or without signs of renal disease.

Preeclampsia is associated with a reduced response to activated protein C

OBJECTIVE

Resistance to activated protein C is an inherited mutation of the coagulation factor V gene, a major factor predisposing to thromboembolic events. The purpose of this study was to investigate the occurrence of heterozygote and homozygote activated protein C resistance in women with preeclampsia.

STUDY DESIGN

Activated protein C resistance and protein C and antithrombin III levels were determined in women (n = 50) with a history of preeclampsia and in controls (50 women with a previous normal pregnancy). The mutation of the factor V gene was analyzed.

RESULTS

Activated protein C resistance was found in 22% of women with previous preeclampsia compared with 10% among controls. Two women in the previous preeclampsia group had a homozygote mutation of factor V; the others were heterozygous. There was a significant difference in the activated protein C ratio between women with previous preeclampsia and the control group, 2.6 +/- 0.4 versus 3.1 +/- 0.5 (p = 0.04). None of the women had protein C or antithrombin III deficiency.

CONCLUSION

The results indicate that activated protein C resistance may be a contributory factor in the pathogenesis of preeclampsia.

Long-term stability of albumin, protein HC, immunoglobulin G, kappa- and lambda-chain-immunoreactivity, orosomucoid and alpha 1-antitrypsin in urine stored at -20 degrees C

The stability of albumin, protein HC, immunoglobulin G, kappa- and lambda-chain immunoreactivity, orosomucoid and alpha 1-antitrypsin in urine stored at -20 degrees C for up to 24 months was investigated. Significant decreases of the median concentration values for protein HC, IgG and alpha 1-antitrypsin were observed for native urine. Addition to urine of a preservative solution containing benzamidinium chloride, EDTA, tris(hydroxymethyl)-aminomethane and azide prevented the decreases of the concentration values for protein HC and IgG but not for alpha 1-antitrypsin. The median concentration values for albumin, orosomucoid and kappa- and lambda-chain immunoreactivity did not change significantly upon storage of native urine, nor for urine with the preservative solution.

Generation of nitrate during dialysis as a measure of nitric oxide synthesis

Nitric oxide (NO) is a recently identified messenger, which influences the local regulation of blood flow and platelets as well as neuronal and inflammatory pathways. Disturbed NO information might be involved in the uremic syndrome and might also cause hypotension during dialysis. To clarify these issues, we analyzed plasma and dialysis fluid concentrations of nitrate, the stable NO metabolite, in 9 patients during hemodialysis. Plasma nitrate was raised at the onset of dialysis as compared with healthy subjects (83 +/- 9 versus 26 +/- 2 mumol/L). The plasma concentration decreased to 20 +/- 2 mumol/L (p < 0.01) during the dialysis. The relative decrease was more pronounced than the relative reduction in creatinine, phosphate, and urea concentrations. A parallel decrease in nitrate was seen in effluent dialysis fluid (32 +/- 4 to 14 +/- 1 mumol/L; p < 0.01). Calculations of the amount of nitrate coming to and from the dialyzer were performed in 7 of the 9 patients, and in 5 of the 7 patients, generation of nitrate within the dialyzer could be postulated. This might explain the paradoxical venodilation noted during hemodialysis.

Beneficial effect of cold dialysate for the prevention of hemodialysis-induced hypoxia

Hypoxia occurs frequently during routine hemodialysis (HD). In this study the effect of dialysate temperature on arterial blood gas parameters was investigated. Ten stable HD patients (2 smokers) were dialyzed for 240 min with each of three different dialysate temperatures: 36.5 degrees C (normal temperature HD; NHD), 38.5 degrees C (warm HD; WHD) and 34.5 degrees C (cold HD; CHD). A cuprophane plate dialyzer was used. The ultrafiltration volume was identical in each patient. Arterial blood gas samples were frequently (approximately 10 times/treatment) taken during the dialysis and immediately analyzed. The dialysate temperature significantly affected PaO2 (p < 0.001) but not PaCO2. We also compared the effect of NHD with that of WHD and CHD, respectively, as regards PaO2. NHD and WHD differed significantly p < 0.01), whereas NHD and CHD were not significantly different. However, the relative PaO2 value (% of the baseline value) at the end of CHD (105 +/- 5%) was significantly higher than after both NHD (96 +/- 4%, p < 0.01) and WHD (91 +/- 3%, p < 0.01). In the case of NHD and WHD the fraction of time during which the patients had a PaO2 value below 80 mm Hg was 62 and 64%, respectively. The corresponding figure for CHD was 44%. Arterial oxygen saturation (SaO2) increased during CHD from 95.2 +/- 0.6 to 96.7 +/- 0.6% (p < 0.05), while SaO2 was unchanged during NHD and WHD. The positive effect of CHD was evident in 7 patients. In 1 patient PaO2 was not affected by the dialysate temperature, while in the remaining 2 patients (smokers) a decrease in PaO2 was induced by WHD as well as CHD. A separate statistical analysis with the 2 smokers excluded was performed, which showed that the dialysate temperature significantly affected PaO2 (p < 0.001). A comparison between NHD and CHD showed a significant difference (p < 0.001), whereas NHD and WHD did not differ significantly. When the 2 smokers were excluded from the analysis the fraction of time with a PaO2 value below 80 mm Hg was 60% during NHD and 56% during WHD, but it was reduced to 31% during CHD. In conclusion, despite the existence of interindividual variations most patients seemed to benefit from cold dialysate for the prevention of dialysis-induced hypoxia.

Analysis of proteinuria: reference limits for urine excretion of albumin, protein HC, immunoglobulin G, kappa- and lambda-immunoreactivity, orosomucoid and alpha 1-antitrypsin

Efficient use of assessment of urine protein excretion in nephrological practice requires adequate reference intervals. To determine the upper reference limits of urine albumin, protein HC (alpha 1-microglobulin, immunoglobulin G (IgG), orosomucoid (alpha 1-acid glycoprotein, alpha 1-antitrypsin, and kappa- and lambda-chain immunoreactivities, the concentrations of these proteins were measured in urine samples from 95 healthy, adult individuals, using rapid, generally available methods and with conditions for urine collection which secured stable protein levels. The obtained values were expressed in mg 1(-1), as the urine protein-creatinine index and as fractional protein-creatinine clearance. No differences were found between the upper reference limits in the first voided morning urine samples and the randomly collected urine samples, nor between the upper reference limits in urine samples collected from males and females. The urinary excretion of the tested proteins did not correlate to age, positive dipsticks for haematuria nor to granular casts in urine sediment. Thus, the same upper reference limits can be used for both sexes and regardless of the type of urine collection. The upper reference limits of urine protein-creatinine index found in this study were: for albumin, 3.8 mg mmol(-1); for protein HC, 0.7 mg mmol; for IgG, 0.8 mg mmol(-1); for orosomucoid, 0.7 mg mmol(-1); for alpha 1-antitrypsin, 0.2 mg mmol(-1), and for kappa-immunoreactivity 0.7 mg mmol(-1). The upper reference limit for lambda-immunoreactivity was below the detection limit.

C4 phenotypes in IgA nephropathy: disease progression associated with C4A deficiency but not with C4 isotype concentrations

IgA nephropathy (IgAN) is a common glomerular disease and is thought to have an immunological origin which may involve complement-mediated pathogenic mechanisms. We performed C4 phenotyping and C4 isotype quantification in 93 IgAN patients in Southern Sweden. Phenotype frequencies did not deviate from those of healthy controls. However, three patients had homozygous C4A deficiency and these all belonged to a group of fifteen patients with end-stage renal failure (p < 0.0035). Progression to end-stage renal failure did not appear to be faster than in other IgAN patients. Both C4A and C4B concentrations were raised in the IgAN patients, but the C4A/C4B concentration ratios did not deviate from those of healthy controls. This indicated that heterozygosity for C4A or C4B deficiency or other reasons for the relatively low concentrations of the protein were not associated with disease susceptibility. There was no correlation between low C4A/C4B ratio and poor prognosis. In conclusion, the findings suggested that homozygous C4A deficiency predisposes to development of end-stage renal failure. The question if this is due to complement dysfunction or to linked genetic factors remains to be elucidated.

Hyperhomocysteinemia in cyclosporine-treated renal transplant recipients

Moderate hyperhomocysteinemia, an independent cardiovascular risk factor, has been reported in renal transplant recipients. In the present study, plasma concentrations of total homocysteine were significantly increased in 120 renal transplant recipients as compared with 60 healthy controls (19.0 +/- 6.9 vs. 11.6 +/- 2.8 mumol/L, P < 0.0001) and as compared with 53 patients without a transplant but with a comparable degree of renal failure (19.0 +/- 6.9 vs. 16.0 4.9 mumol/L, P < 0.01). There was a significant inverse correlation between glomerular filtration rates and plasma homocysteine concentrations in the renal transplant recipients (r = -0.52, P < 0.0001). Groups of renal transplant recipients, with and without cyclosporine, and renal patients without a transplant were studied; these groups were comparable regarding age, sex distribution, glomerular filtration rate, and folate and vitamin B12 concentrations. Renal transplant recipients on cyclosporine had significantly higher plasma homocysteine concentrations than those not on cyclosporine (19.5 +/- 7.6 vs. 16.2 +/- 4.8 mumol/L, P < 0.05), and the patients without a transplant (19.5 +/- 7.6 vs. 16.0 +/- 4.9 mumol/L, P < 0.01). Thus, the hyperhomocysteinemia of renal transplant recipients not treated with cyclosporine, and that of renal patients without a transplant probably is explained by the same mechanism: renal insufficiency. An additional mechanism seems to operate in renal transplant recipients treated with cyclosporine. The lack of correlation between the concentrations of plasma homocysteine and red cell folate in these patients suggests that cyclosporine interferes with folate-assisted remethylation of homocysteine. Plasma homocysteine concentrations were significantly increased in 24 patients with a history of atherosclerotic complications as compared with the remaining 96 renal transplant recipients (20.8 +/- 4.4 vs. 18.5 +/- 7.3 mumol/L, P < 0.01).

The effect of reduced glomerular filtration rate on plasma total homocysteine concentration

The concentration of homocysteine in plasma has been shown to be increased in renal failure, possibly contributing to the accelerated atherosclerosis observed in uraemic patients. The aim of the present study was to document the relationship between plasma total homocysteine (tHcy) concentrations and glomerular filtration rates (GFR) in highly selected patients, with renal function ranging from normal to dialysis dependency. GFR was defined as the plasma clearance of iohexol; a more accurate method than the creatinine-based estimations applied in previous studies. Plasma tHcy concentrations were highly correlated to GFR (r = -0.70, p < 0.0001) and were significantly increased already in moderate renal failure. According to a multiple regression analysis, GFR and red cell folate concentrations independently predicted plasma tHcy concentrations, whereas those of serum creatinine, plasma pyridoxal-5-phosphate, urine albumin and urine alpha-1-microglobulin (a marker of tubular damage) did not. Thus, GFR seems to be a better determinant of plasma tHcy concentration than serum creatinine concentration. Plasma total cysteine and total cysteinylglycine concentrations followed the same pattern as those of tHcy.

Cytokines in childhood hemolytic uremic syndrome and thrombotic thrombocytopenic purpura

Serum and urine cytokines were analyzed in children with hemolytic uremic syndrome (HUS) and thrombotic thrombocytopenic purpura (TTP). Interleukin-6 (IL-6) was elevated in the serum of 33 of 35 children with HUS (94%) and in 2 of 2 children with recurrent TTP. Serum IL-6 was higher in children with HUS who developed anuria, extrarenal manifestations during the acute phase of illness and/or chronic renal sequelae. Tumor necrosis factor-alpha (TNF-alpha) was detected in the serum of 7 patients with HUS (20%) and 1 patient with TTP. IL-6 and TNF-alpha were elevated in the urine of 4 of 4 children with HUS and 2 of 2 children with TTP. Urinary levels were higher than serum levels, suggesting local production of cytokines in the urinary tract. Sequential serum and urine samples showed that IL-6 levels varied with disease activity. IL-6 and TNF-alpha were not detected in the serum (n = 25) and urine (n = 15) of healthy children. We conclude that IL-6 in urine may be used to monitor disease activity in HUS and TTP.

The effect of dialysis on radiocaesium in man

Dialysis is used for cleaning the blood in patients with end-stage renal disease. The most common methods are hemodialysis (HD) and peritoneal dialysis (PD). Dialysis patients might constitute a critical group because of poor elimination of radioactive elements ingested. On the other hand dialysis may be a useful decontamination method for radioactivity. The effect of dialysis on the turnover of radiocaesium was studied in 10 HD patients and 4 PD patients. The dialysis fluid, which contains electrolytes and the metabolic waste products, was analyzed for radiocaesium. In this connection the patients were whole-body counted for radiocaesium and 40K. The results show that HD patients generally have a lower body burden of radiocaesium than normal subjects, while PD patients show normal levels. At steady state both dialysis methods eliminate slightly less radiocaesium than normal kidneys do, but in the case of HD during a much shorter time. The calculated effective half-life for radiocaesium was normal in the HD patients, and somewhat longer in the PD patients. Considering that HD is performed only for 12-15 h weekly, the elimination rate of radiocaesium by HD is much higher compared with that by normal kidneys. Thus, HD might constitute an important method for decontamination of radiocaesium after accidental internal contamination.

Hepatitis C superinfection in hepatitis C virus (HCV)-infected patients transplanted with an HCV-infected kidney

Hepatitis C virus (HCV) genotypes, determined by polymerase chain reaction with type-specific primers, were studied in 5 already HCV-infected patients receiving kidneys from HCV-infected cadaver donors. Three patients were investigated retrospectively using stored pre- and posttransplantation sera and followed 18-28 months after transplantation. Two recipients with HCV genotype 2b infection had received kidneys from 1 genotype 3a-infected donor. In 1 recipient, HCV 2b was replaced by the donor's type; in the other recipient, a prolonged mixed infection of 3a and 2b occurred. Persistent alanine aminotransferase (ALT) elevation (3- to 5-fold) appeared in both patients. The third patient, also HCV 2b infected when transplanted with an HCV 3a-infected kidney, remained infected with HCV 2b only. Two patients, one with HCV genotype 1b and the other with genotype 3a, were followed prospectively with frequent bleeds (initially biweekly) and genotyping over 14 months after they had received kidneys from 1 HCV genotype 1a-infected donor. The HCV 1b-infected recipient remained infected with 1b only and had minimal biochemical signs of liver injury. In the other recipient, mixed infection of 3a and 1a appeared at week 3 and persisted for several weeks, until only genotype 1a could be detected. This patient had elevated ALT levels before transplantation. After onset of mixed infection, ALT levels increased further for several weeks, and returned to pretransplantation levels when only HCV 1a was found. HCV-infected kidneys transplanted into HCV-infected recipients gave 3 different virus patterns. Most patients benefitted in the short term, but some super-infected patients experienced increased liver damage.

Evidence that reduced lipoprotein lipase activity is not a primary pathogenetic factor for hypertriglyceridemia in renal failure

The aim of the study was to document postheparin plasma lipoprotein lipase (LPL) and hepatic lipase activities and relate these to serum lipid, lipoprotein and apolipoprotein concentrations in 85 patients with kidney function ranging from normal to dialysis dependency. Strict selection criteria were applied in order to exclude conditions other than renal failure which may influence lipid metabolism. Stress was laid on minimizing proteinuria and inflammatory activity. The changes in the lipoprotein pattern were numerically strikingly modest compared to those previously reported. This probably reflected the intention to elucidate the contribution of reduced renal function as such to the dyslipoproteinemia of renal failure, a condition often associated with confounding factors. Significant increases in serum concentrations of triglycerides and apolipoprotein CIII were already observed in moderate renal failure, whereas serum concentrations of high density lipoprotein cholesterol and plasma LPL activities were decreased only in severe renal failure. Plasma LPL activities were not significantly reduced in hemodialysis patients (probably due to anticoagulation with low molecular weight heparin), but serum concentrations of triglycerides and apolipoprotein CIII were significantly increased. A multiple regression analysis, taking glomerular filtration rate, LPL and apolipoprotein CIII into account, showed that both plasma LPL activity and serum apolipoprotein CIII concentration independently predicted serum triglyceride concentration. However, serum apolipoprotein CIII concentration was a much stronger predictor than plasma LPL activity. Thus, a decrease in LPL activity does not seem to be a prerequisite for the hypertriglyceridemia of uremia, but it probably accentuates this condition.(ABSTRACT TRUNCATED AT 250 WORDS)

Dose regimen adjustment for milrinone in congestive heart failure patients with moderate and severe renal failure

This study was designed to test a proposed dose modification for intravenous milrinone in congestive heart failure patients (CHF, NYHA I-II) with either moderate or severe renal impairment. All the patients were administered an intravenous loading dose of drug at 50 micrograms kg-1 over 10 min. This was followed by an 18 h maintenance infusion of milrinone at 0.45 or 0.35 micrograms kg-1 min-1 for the moderate (chromium-EDTA clearance of 31-75 mL min-1, n = 10) and severe renally impaired subjects (chromium-EDTA of clearance 10-30 mL min-1, n = 11), respectively. Plasma and urine samples were collected for up to 34 h and analysed for parent drug by validated HPLC methods. The mean (+/- s.d.) steady-state plasma concentrations of milrinone were within the therapeutic range (100-300 ng mL-1) for both groups, with values of 239 +/- 71 ng mL-1 and 269 +/- 32 ng mL-1 for the moderate and severe patients, respectively. No statistical differences were observed between the steady-state values for the two groups. With the exception of two patients per group, individual steady-state levels were also within the therapeutic range. Those outside the nominal range showed steady-state levels, ranging between 308 and 353 ng mL-1, that were not associated with any serious adverse events.(ABSTRACT TRUNCATED AT 250 WORDS)

Elevated plasma levels of acute phase proteins in mesangioproliferative glomerulonephritis, membranous nephropathy and IgA nephropathy

In order to study the possible role of active inflammatory processes in clinical indolent primary chronic glomerulonephritides, plasma concentrations of the acute phase proteins: alpha 1-antitrypsin, haptoglobin, orosomucoid and C-reactive protein were measured in 166 glomerulonephritis patients. The patients had a diagnosis of either mesangioproliferative glomerulonephritis, membranous nephropathy or immunoglobulin A nephropathy and were divided in two groups, one with heavy urinary albumin losses and one with moderate to slight urinary albumin excretion. The median plasma concentration values for alpha 1-antitrypsin, haptoglobin and orosomucoid were increased in all three kinds of the investigated glomerulonephritides with exception for orosomucoid in patients with heavy urinary albumin losses and in the membranous nephropathy group. The plasma concentration values for C-reactive protein were not elevated at all in the material. The increase of plasma levels of acute phase proteins could be the result of persistent inflammatory stimuli that occur in primary chronic glomerulonephritides. The finding of unchanging plasma levels of C-reactive protein in contrast to increased concentrations of the other acute phase proteins could be of significance in diagnosing infections or other inflammatory diseases in patients with chronic glomerulonephritis.

Circulating neuropeptide Y in plasma from uremic patients consists of multiple peptide fragments

Increased plasma levels of neuropeptide Y (NPY)-like immunoreactivity (p-NPY-LI) have been described in hemodialysis (HD) patients. In this investigation the effect of a standard HD on p-NPY-LI, analyzed by radioimmunoassay and reverse-phase high performance liquid chromatography (HPLC), was studied. During dialysis p-NPY-LI increased from 128 +/- 5 to 154 +/- 8 pmol/l (p < 0.01). The change in p-NPY-LI during the treatment correlated with the ultrafiltration volume (rs = +0.72, p < 0.05). The HPLC separation revealed a complex pattern of NPY-immunoreactive peptides. This was true of the plasma of the control subjects as well as of the uremic plasma. In the case of the controls and the HD patients prior to dialysis, the amount of NPY-LI was rather small. After the dialysis qualitative as well as quantitative changes of the chromatogram were found. Some of the peaks seemed to have a retention time similar to that of the known fragments of synthetic human NPY used as markers. In conclusion, an increase in p-NPY-LI occurred during the dialysis, probably due to fluid removal. The increased level of NPY-LI in uremic plasma represents a mixture of different NPY fragments.

Occurrence of autoantibodies directed against myeloperoxidase and elastase in patients treated with hydralazine and presenting with glomerulonephritis

We have undertaken an investigation retrospectively of 21 patients with positive antinuclear antibodies, who had been on hydralazine treatment and developed a glomerulonephritis. Four patients had circulating antimyeloperoxidase (MPO) and two of them were concluded to have a hydralazine-induced glomerulonephritis, corresponding to a frequency of 10%. These two patients had antibodies of IgG and IgM class directed against myeloperoxidase (MPO), and also antibodies against elastase. These two patients had also a biopsy proven extracapillary glomerulonephritis with focal segmental necrosis. Antibodies against elastase were furthermore seen in three patients with proliferative glomerulonephritis and in one patient with membranoproliferative glomerulonephritis. This study confirms an association between circulating anti-MPO and a histopathological picture compatible with extracapillary proliferation and focal segmental necrosis. From a clinical, histopathological and serological point of view it can be concluded that in two patients the glomerulonephritis was associated with antibody evidence of an autoimmune side effect.

Dialysis fluid temperature and vasoactive substances during routine hemodialysis

Blood pressure stability is better during cold hemodialysis (HD). This has mainly been attributed to a more pronounced sympathetic activation during cold than during warm HD. The authors studied the effect of dialysate temperature on vasoactive peptides, noradrenaline (NA), and renin (PRA). Ten hemodynamically stable patients were dialyzed for 240 min with each of two dialysate temperatures: 38.5 degrees C (warm HD = WHD) and 34.5 degrees C (cold HD = CHD). A decrease (P < 0.05) in blood pressure occurred during WHD; however, during CHD, blood pressure was stable. There were no differences in vasoconstrictors between the two regimens. There was a decrease in NA (P < 0.05), a tendency of PRA to increase (NS owing to a large statistical spread), while arginine vasopressin was unchanged. During CHD, there was a small increase in neuropeptide Y (NPY); however, during WHD, NPY only tended to increase. However, the relative NPY levels (percent of baseline levels) after WHD and CHD did not differ. The vasodilator response was similar during both treatments. Calcitonin gene related peptide was unaltered. Motilin tended to decrease initially, but then increased (P < 0.05) to baseline levels. An increase occurred in beta-endorphin (P < 0.05) and substance P(P < 0.01). There was an initial rise (P < 0.05) in vasoactive intestinal peptide (VIP), followed by a tendency to decrease during the remainder of treatment. The authors concluded that blood pressure stability was better during CHD. However, this was not reflected by differences in plasma levels of the vasoactive peptides, nor did they find any difference in the sympathetic drive between the two regimens.

Stability of albumin, protein HC, immunoglobulin G, kappa- and lambda-chain immunoreactivity, orosomucoid and alpha 1-antitrypsin in urine stored at various conditions

Urine samples from 10 randomly selected patients with advanced renal disease were each divided into six aliquots and a preservative solution containing benzamidinium chloride, EDTA, tris(hydroxymethyl)-aminomethane and azide was then added to three of the aliquots. Aliquots with and without additive were then stored at room temperature for up to 7 days, at 4 degrees C for up to 30 days and at -20 degrees C for up to 6 months. The concentrations of albumin, protein HC, IgG, orosomucoid and alpha 1-antitrypsin as well as the kappa- and lambda-chain immunoreactivities in the samples were determined by automated immunoturbidimetry or by single radial immunodiffusion after 1, 3, 7, 14, 30, 90 and 180 days of storage. All investigated proteins, except alpha 1-antitrypsin in native urine, were stable for 7 days in the samples stored at room temperature both in the presence and absence of additives. All investigated proteins, except alpha 1-antitrypsin in native urine, were stable for 30 days in the samples stored at 4 degrees C both in the presence and absence of additives. A more complex pattern was observed for the stability of the proteins in the frozen samples. The IgG level decreased rapidly in several samples stored without additives but not in samples stored with additives. The alpha 1-antitrypsin concentration decreased rapidly to about 50% of the initial value in several samples stored both with and without additives. The rate of the decrease for both the IgG and the alpha 1-antitrypsin level varied between samples and the main decrease for several samples was seemingly caused by the freezing and/or thawing per se and not by the storage period in between.

Changes in plasma levels of vasoactive substances during routine acetate and bicarbonate hemodialysis

Hemodynamic stability is better preserved during bicarbonate hemodialysis compared to acetate. We have studied the effects of bicarbonate (HDB) and acetate hemodialysis (HDA) on plasma levels of vasoactive substances. The treatments were performed for 270 min. A cuprophan plate dialyzer was used. The ultrafiltration volume and the ultrafiltration rate were identical in the individual patients during the two treatments. In the case of vasoconstrictors there was an increase in neuropeptide Y (NPY) (20%, p < 0.01) during HDB and arginine vasopressin (AVP) was unchanged. Unlike this was the response during HDA when there was no change in NPY and a decrease in AVP (38%, p < 0.01). An increase in noradrenaline (NA) (41%, p < 0.05) occurred during HDA different from what was the case during HDB. There was a gradual increase in renin (PRA) during both HDB (141%, p < 0.05) and HDA (148%, p < 0.01). With respect to vasodilators there were no differences between the two regimes regarding calcitonin gene-related peptide (CGRP) and motilin (MOT). The change in substance P (SP) during the treatments was also similar but somewhat more pronounced during HDB. Thus, an initial rise occurred (HDB, 81%, p < 0.01; HDA, 36%, p < 0.05) followed by a decrease (HDB, 26%, p < 0.05) or a tendency to decrease (HDA, 12%, p = 0.058) during the remaining part of the treatment. A rise in beta-endorphin (beta-END) occurred during HDB (10%, p < 0.05) but not during HDA. An increase in vasoactive intestinal peptide (VIP) occurred during HDB (27%, p < 0.05) different from the decrease during HDA (11%, p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Low-dose simvastatin is a well-tolerated and efficacious cholesterol-lowering agent in ciclosporin-treated kidney transplant recipients: double-blind, randomized, placebo-controlled study in 40 patients

The high prevalence of hypercholesterolemia in kidney transplant recipients probably contributes to the high cardiovascular mortality in these patients. Except for diet, there is no generally recommended cholesterol-lowering treatment. We conducted a double-blind, randomized, placebo-controlled study with low-dose simvastatin in 40 ciclosporin (CS)-treated kidney transplant recipients during 16 weeks, focusing on side effects and dose finding. In the simvastatin group, the mean serum total and LDL cholesterol concentrations decreased by 23 and 33%, respectively, and the mean serum HDL cholesterol concentration increased by 12%, after 4 weeks of treatment with simvastatin 10 mg daily. Increasing the dose to 20 mg daily in a few patients only resulted in marginal further reductions of the serum cholesterol concentrations at the expense of doubling the plasma simvastatin 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitory activity concentrations. The differences between the changes in the serum cholesterol concentrations in the simvastatin group and the negligible changes in the placebo group were statistically significant. There was no case of proximal myopathy and the serum creatine kinase concentrations did not differ between treatment groups. In conclusion, low-dose simvastatin appears to be a well tolerated and efficacious cholesterol-lowering treatment in CS-treated kidney transplant recipients. Simvastatin 10 mg daily seems to be the most suitable dose for the majority of these patients.

Delayed decrease in plasma levels of atrial natriuretic peptide during cold hemodialysis

The high plasma levels of the vasodilating hormone atrial natriuretic peptide (alpha-ANP), observed in patients with chronic renal failure, decrease substantially during hemodialysis (HD), probably owing to volume reduction. Cardiovascular stability is better maintained by the use of cold dialysate although underlying mechanisms are unknown. In order to investigate the effects of different dialysate temperatures on hemodynamic stability and plasma levels of immunoreactive ANP (p-irANP), 10 stable HD patients were dialyzed with bicarbonate dialysis fluid for 240 min with each of 3 different dialysate temperatures: 36.5 degrees C (normal HD; NHD), 38.5 degrees C (warm HD; WHD) and 34.5 degrees C (cold HD; CHD). A Cuprophan plate dialyzer was used. The ultrafiltration volume and ultrafiltration rate were identical in each patient during the treatments. p-irANP was determined by radioimmunoassay, using 2 antisera which different cross-reactivity to ANP-related peptides. During NHD a nonsignificant decrease in mean arterial blood pressure from 111 +/- 5 to 103 +/- 8 mm Hg was observed. A significant (p < 0.05) decrease in mean arterial blood pressure from 109 +/- 4 to 96 +/- 6 mm Hg occurred during WHD, while during CHD it remained stable (111 +/- 4 before, 112 +/- 5 mm Hg after). Irrespective of the dialysate temperature or the antiserum used, p-irANP decreased significantly (p < 0.05) during the treatment. The reduction in p-irANP was delayed during CHD, the decrease being significantly (p < 0.05) less pronounced after 120 min. At the end of the treatment no significant difference was observed between the regimes.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of erythropoietin on muscle metabolic rate, as measured by direct microcalorimetry, and ATP in hemodialysis patients

Ten anemic hemodialysis patients were treated for 6-14 months with human recombinant erythropoietin (EPO). The mean hemoglobin level significantly increased by 42%. Pretreatment skeletal muscle heat production rate at rest, as determined by direct microcalorimetry, was lower than normal (p < 0.03), indicating decreased metabolic activity. ATP levels in muscle were inversely correlated (rs = -0.66, p < 0.05) with the heat production values. The latter significantly increased by about 40% and were almost normalized by the therapy, whereas a decline in the mean ATP level was seen, from 14.8 to 13.2 mumol g-1 of muscle (p = 0.06). We hypothesize that the lowered ATP concentration in muscle after treatment might have been due to an enhanced ATP consumption in parallel with improved muscle strength. Alternatively, since acidosis prior to treatment might have altered the equilibrium state of the creatine kinase reaction towards ATP production, it is possible that the improved oxygenation after EPO had increased pH in the muscle and catalyzed the transfer of phosphate from ATP to PCr. It is concluded that EPO treatment can almost normalize the decreased muscle metabolic rate in hemodialysis patients, and that the anemia per se seems to be an important cause of the deranged metabolism in striated muscle.

Results, principles and pitfalls in the management of renal AA-amyloidosis; a 10-21 year followup of 16 patients with rheumatic disease treated with alkylating cytostatics

OBJECTIVE

To assess renal functional outcome at 10-21 years in 16 consecutive patients with rheumatic disease, treated with alkylating agents for secondary renal AA-amyloidosis, and to review management principles developed during 21 years.

METHODS

Renal function was assessed by S-creatinine and the albumin/creatinine clearance ratio, and arthritic activity by joint score and C-reactive protein (CRP). In the event of signs of renal deterioration, cyclophosphamide, or since 1975 chlorambucil, was given until stable remission of the arthritis was obtained.

RESULTS

Of the 7 cases of precipitous uremia that occurred, 4 were not treated with cytostatics at the patients' local hospitals. By 1992, median survival of renal function was 11 years (range 4-21). At 10 years 12 (75%) still had kidneys with preserved function, and at that stage accounted for 22 instances of renal deterioration treated with alkylating agents for periods of 6-45 months (median 13). Renal function was improved in 18 of these instances, and deterioration arrested in 3, the general trend being stabilized or moderately increased S-creatinine and successively declining proteinuria. Prompt institution of corticosteroid treatment is regarded as indispensable at increase of CRP/S-AA due to infection or surgery.

CONCLUSION

Our results indicate that the survival of renal function may be substantially prolonged (compared to no treatment) when cyclophosphamide, or preferably chlorambucil, is appropriately administered at signs of kidney deterioration due to active arthritis, and lifelong, continuous monitoring maintained.

The effect of high-dose pyridoxine and folic acid supplementation on serum lipid and plasma homocysteine concentrations in dialysis patients

Pyridoxine and folic acid supplementation in dialysis patients is a matter of debate. This study was performed to estimate the effects of pharmacologic doses of these vitamins on serum lipid and plasma homocysteine concentrations, which are known to be high in dialysis patients. Both hemodialysis and continuous ambulatory peritoneal dialysis patients were included in the study. Pyridoxine supplementation had a mild but significant cholesterol-lowering effect (7%). Folic acid supplementation significantly lowered plasma homocysteine concentrations by a mean of 30%. There was a strong, inverse correlation between blood folate and plasma homocysteine concentrations. These results indicate that daily supplementation with pyridoxine 300 mg and folic acid 5 mg has a beneficial effect on the cardiovascular risk profile in dialysis patients.

Changes in plasma levels of vasoactive peptides during standard bicarbonate hemodialysis

During bicarbonate hemodialysis, there is an increase in peripheral vascular resistance of nonadrenergic origin, counteracting the hypotensive effect of fluid removal during the course of the dialysis. In this study, the plasma levels of vasoactive regulatory peptides, noradrenaline and renin, were investigated in 11 patients with chronic renal failure during standard bicarbonate hemodialysis (STHD) for 270 min. As regards vasoconstrictors, an increase in gamma 2-melanocyte-stimulating hormone (gamma 2-MSH), neuropeptide Y (NPY) and plasma renin activity (PRA) occurred. However, arginine vasopressin and noradrenaline were unchanged. With respect to vasodilators, calcitonin gene-related peptide was not changed. An initial increase in beta-endorphin (beta-END) occurred, followed by a decrease during the remaining part of the treatment. Motilin decreased during the first part of the treatment but increased to the baseline level during the latter part. An increase in substance P was observed while vasoactive intestinal peptide decreased. We conclude that an increase in vasoconstricting substances (gamma 2-MSH, NPY, PRA) occurs during STHD, probably owing to the decrease in plasma volume. With the exception of beta-END, the changes in vasodilators were fairly small. The data suggest that vasoactive substances might participate in the hemodynamic response to hemodialysis.

Changes in plasma levels of vasoactive peptides during sequential bicarbonate hemodialysis

The hemodynamic response to isolated ultrafiltration (IUF) is characterized by a vasoconstriction, while there is no significant change in peripheral vascular resistance during isovolemic bicarbonate hemodialysis (IVHD). The present investigation was designed to study the plasma levels of vasoactive regulatory peptides together with noradrenaline (NA) and plasma renin activity (PRA) in 11 patients during sequential hemodialysis (SQHD) - IUF for 60 min, followed by IVHD for 210 min. During IUF, the vasoconstrictors arginine vasopressin (AVP), gamma 2-melanocyte-stimulating hormone (gamma 2-MSH), neuropeptide Y (NPY), NA and PRA increased. During IVHD, NPY and PRA remained unchanged on a higher level. A decrease in AVP below the baseline and in gamma 2-MSH and NA to the baseline levels occurred during IVHD. In the case of vasodilators, there were no changes in calcitonin gene-related peptide or motilin during SQHD. An increase in beta-endorphin (beta-END) occurred during IUF, followed by a decrease during IVHD. Substance P and vasoactive intestinal peptide were unchanged during IUF but decreased during IVHD. We conclude that SQHD is characterized by an increase in all the measured vasoconstrictors during IUF in response to loss of fluid, and by a decrease in some vasoconstrictors (AVP, gamma 2-MSH, NA) during IVHD. With the exception of beta-END, there were no changes or only minor ones in vasodilators during SQHD. There are changes in plasma levels of vasoactive substances during SQHD but the importance of these changes for the hemodynamic adaptation to ultrafiltration and dialysis needs to be studied further.