[Future of rheumatologists: what are the perspectives? : Survey of resident physicians in rheumatology in middle Germany]

BACKGROUND AND OBJECTIVE

The work environment for rheumatologists has significantly changed over the last years. The healthcare of patients with rheumatic diseases is at risk due to the age structure of specialized rheumatologists in middle Germany and the limited availability of training positions for rheumatologists. In this context, it is important to have detailed information on the resident physicians in rheumatology concerning their own visions regarding their future professional career.

MATERIAL AND METHODS

A questionnaire was sent to resident physicians in 25 rheumatology training hospitals in the middle of Germany (Saxony, Saxony-Anhalt and Thuringia). The questionnaire was completed and returned by 27 participants (17 women and 10 men).

RESULTS

Most of the participants (60%) aimed to qualify as a specialist in internal medicine followed by a specialization in rheumatology (altogether training for a minimum of 8 years). After finishing training 44% would prefer to work in an outpatient setting while 30% planned to work in a combined outpatient and clinical setting. Of the participants 48% would prefer to work as part-time rheumatologists and 74% (women 94% and men 40%) were interested in employment in an outpatient medical healthcare center. The compatibility of family and work as well as the work-life balance was considered to be highly relevant for the future professional life.

CONCLUSION

Less than half of the participants intended to work exclusively in an outpatient setting after completing the training in rheumatology. In addition, the participants preferred a part-time employment with compatibility of professional and private life. Consequently, alternative models of employment should be created in rheumatology to be attractive for future physicians. On the other hand, the study revealed that the independent rheumatological practice has a lower priority for the young rheumatologists taking part in this survey.

Long-Term Efficacy and Safety of Biosimilar CT-P10 Versus Innovator Rituximab in Rheumatoid Arthritis: 48-Week Results from a Randomized Phase III Trial

OBJECTIVE

The aim of this study was to investigate long-term clinical outcomes of extended treatment with CT-P10, a rituximab biosimilar, compared with rituximab reference products sourced from the USA and the EU (US-RTX and EU-RTX) in rheumatoid arthritis (RA) for up to 48 weeks.

METHODS

In this multinational, randomized, double-blind trial, adults with active RA received up to two courses of CT-P10, US-RTX, or EU-RTX alongside methotrexate. Efficacy endpoints included Disease Activity Score 28-joint count (DAS28) and American College of Rheumatology (ACR) response rates. Pharmacokinetics, pharmacodynamics, immunogenicity, and safety were also assessed.

RESULTS

Of 372 patients randomized to the study drug, 330 (88.7%) completed the second treatment course. Mean change from baseline to week 48 in DAS28-C-reactive protein was comparable in the CT-P10 and combined rituximab (US-RTX and EU-RTX) groups (- 2.7 and - 2.6, respectively). ACR20, ACR50, and ACR70 response rates at week 48 indicated no differences between groups (80.6%, 55.4%, and 31.7% vs. 79.8%, 53.9%, and 33.7% in the CT-P10 and combined rituximab groups, respectively). Similar improvements in the Health Assessment Questionnaire Disability Index and all medical outcomes in the Short Form 36-Item Health Survey, including physical and mental health, were seen in all groups. At week 48, antidrug antibodies were detected in 4.9%, 9.4%, and 8.6% of patients in the CT-P10, US-RTX, and EU-RTX groups, respectively. CT-P10 and rituximab displayed similar pharmacokinetic, pharmacodynamic, and safety profiles.

CONCLUSION

CT-P10 was similar to EU-RTX and US-RTX in terms of efficacy, pharmacokinetics, pharmacodynamics, immunogenicity, and safety up to week 48. CLINICALTRIALS.

GOV IDENTIFIER

NCT02149121.

Comparison of biosimilar CT-P10 and innovator rituximab in patients with rheumatoid arthritis: a randomized controlled Phase 3 trial

This multinational, randomized, double-blind trial, (ClinicalTrials.gov identifier NCT02149121) was designed to demonstrate equivalence in pharmacokinetics and efficacy between CT-P10 and innovator rituximab (RTX) in patients with rheumatoid arthritis (RA). Adults with active RA were treated with CT-P10, United States-sourced RTX (US-RTX; Rituxan®), or European Union-sourced RTX (EU-RTX; MabThera®) at weeks 0 and 2. The co-primary pharmacokinetic endpoints were area under the serum concentration–time curve (AUC) from time zero to last measurable concentration (AUC_0–last), AUC from time zero to infinity (AUC_0–∞), and maximum concentration (C_max) after two infusions. The primary efficacy endpoint was change from baseline to week 24 in Disease Activity Score using 28 joints-C-reactive protein (DAS28-CRP). Pharmacodynamics, immunogenicity, and safety were also assessed. 372 patients were randomly assigned to CT-P10 (n = 161) or RTX (n = 211 [US-RTX, n = 151; EU-RTX, n = 60]). For the co-primary pharmacokinetic endpoints, 90% confidence intervals (CI) for ratios of geometric means (CT-P10/US-RTX, CT-P10/EU-RTX or EU-RTX/US-RTX) all fell within the equivalence margin of 80–125%. Adjusted least squares (LS) mean (standard error) change from baseline in DAS28-CRP at week 24 was −2.13 (0.175) for CT-P10 and −2.09 (0.176) for RTX. The 95% CI (−0.29, 0.21) of the estimated treatment difference between CT-P10 and RTX (−0.04) was entirely within the efficacy equivalence margin of ±0.5. Pharmacodynamics, immunogenicity, and safety profiles were similar for CT-P10 and RTX. The pharmacokinetics of CT-P10, US-RTX, and EU-RTX were equivalent. CT-P10 and RTX were also equivalent in terms of efficacy and displayed similar pharmacodynamic, immunogenicity, and safety profiles up to week 24.

[Improvement of the diagnostic accuracy in patients with suspected rheumatic disease by preselection in the early arthritis clinic : An alternative to the appointment service point model of the Healthcare Improvement Act]

The diagnosis and treatment of inflammatory rheumatic diseases can be delayed by a long waiting period for an appointment with a rheumatologist. This study investigated whether preselection of patients in an early arthritis clinic is a suitable tool to improve this situation. In 2006 an early arthritis clinic was founded by the Collaborating Center of Rheumatology in Halle (Saale). General practitioners refer patients by using a special registration form that helps to identify patients with an early joint swelling or inflammatory back pain. Patients are then allocated to a pool of participating rheumatologists and are seen by one of them within 2 weeks. For our scientific evaluation the data of 248 patients from the early arthritis clinic and data of 187 regular patients were gathered by means of an additional questionnaire for rheumatologists and patients. In the early arthritis clinic 40.3 % of patients received the diagnosis of an inflammatory rheumatic disease compared with 19.3 % in the control group. In the latter group 51 % were diagnosed as having degenerative joint or spine disorders compared with 22 % in patients from the early arthritis clinic; however, 61 % of patients who were referred to the early arthritis clinic did not fulfill the criteria of the registration form. On the other hand, patients in this group fulfilling these criteria had an inflammatory rheumatic disease in 68.1 % of the cases. The mean duration of symptoms at the time of first rheumatological consultation was significantly shorter in the early arthritis clinic than in the control group (6 vs. 39 months). Our data demonstrate that the preselection of patients can serve as a useful instrument to guide the referral of patients to rheumatologists. The high percentage of patients who did not fulfil the criteria of the registration form indicates that a further improvement of this form is necessary and stresses the need for intensive communication between rheumatologists and general practitioners. Early arthritis clinics may be an alternative to the current efforts of the legislative authorities to improve specialist care by centralized distribution of specialist appointments.

In Vitro Evaluation of Intra-Aneurysmal, Flow-Diverter-Induced Thrombus Formation: A Feasibility Study

BACKGROUND AND PURPOSE

Intracranial aneurysm treatment by flow diverters aims at triggering intra-aneurysmal thrombosis. By combining in vitro blood experiments with particle imaging velocimetry measurements, we investigated the time-resolved thrombus formation triggered by flow diverters.

MATERIALS AND METHODS

Two test setups were built, 1 for particle imaging velocimetry and 1 for blood experiments, both generating the same pulsatile flow and including a silicone aneurysm model. Tests without flow diverters and with 2 different flow-diverter sizes (diameter: 4.5 and 4.0 mm) were performed. In the blood experiments, the intra-aneurysmal flow was monitored by using Doppler sonography. The experiments were stopped at 3 different changes of the spatial extent of the signal.

RESULTS

No thrombus was detected in the aneurysm model without the flow diverter. Otherwise, thrombi were observed in all aneurysm models with flow diverters. The thrombi grew from the proximal side of the aneurysm neck with fibrin threads connected to the flow diverter and extending across the aneurysm. The thrombus resulting from the 4.0-mm flow diverter grew along the aneurysm wall as a solid and organized thrombus, which correlates with the slower velocities near the wall detected by particle imaging velocimetry. The thrombus that evolved by using the 4.5-mm flow diverter showed no identifiable growing direction. The entire thrombus presumably resulted from stagnation of blood and correlates with the central vortex detected by particle imaging velocimetry.

CONCLUSIONS

We showed the feasibility of in vitro investigation of time-resolved thrombus formation in the presence of flow diverters.

Impaired endothelium-dependent vasodilatation in renal failure in humans

BACKGROUND

The main causes of death in patients with chronic renal failure (CRF) are cardiovascular complications. The aim of the present study was to compare endothelium-dependent vasodilatation (EDV) in patients with chronic renal failure with a control population controlling for hypertension, diabetes mellitus and hypercholesterolaemia.

METHODS

Fifty-six patients with moderate CRF (mean creatinine clearance 29.4 ml/min/1.73 m(2)) underwent evaluation of EDV and endothelium-independent vasodilatation (EIDV) by means of forearm blood flow (FBF) measurements with venous occlusion plethysmography during local intra-arterial infusions of methacholine (Mch, 2 and 4 microg/min evaluating EDV) and sodium nitroprusside (SNP, 5 and 10 microg/min evaluating EIDV). Fifty-six control subjects without renal impairment underwent the same investigation.

RESULTS

Infusion of Mch increased FBF significantly less in patients with renal failure than in controls (198 vs 374%, P<0.001), whereas no significant difference was seen regarding the vasodilatation induced by SNP (278 vs 269%). The differences in EDV between the groups were still significant after controlling for hypertension, blood glucose, and serum cholesterol in multiple regression analysis (P<0.001). EDV was related to serum creatinine (r=-0.37, P<0.01), creatinine clearance (r=0.45, P<0.005) and to serum triglyceride levels (r=-0.29, P<0.005) in the CRF group.

CONCLUSIONS

Patients with moderate CRF have an impaired EDV even after correction for traditional cardiovascular risk factors and this impairment is related to the degree of renal failure.

The use of pretransplant erythropoietin to normalize hemoglobin levels has no deleterious effects on renal transplantation outcome

BACKGROUND

The aim of this study was to establish the outcome of renal transplantation in patients given pretransplant erythropoietin (EPO) treatment targeted at reaching a normal hemoglobin concentration (Hb), compared to those given EPO-treatment aimed at maintaining subnormal Hb.

METHODS

A total of 416 patients from Scandinavian countries and with renal anaemia were enrolled to examine the effects of increasing Hb from a subnormal level (90-120 g/liter) to a normal level (135-160 g/liter) by EPO treatment. Half of the patients were randomized to have their Hb increased, with the other half randomized to maintain a subnormal Hb. Thirty-two patients from the normal Hb group and 24 patients from the subnormal group received a renal graft during the study period. The outcomes of these transplantations were examined prospectively for 6 months.

RESULTS

Preoperative Hb levels were 143+/-17 and 121+/-14 g/liter in the two groups, respectively (P<0.0001). The Hb remained higher in the normal Hb group during the first 2 weeks after transplantation. The percentage of patients requiring postoperative blood transfusions in the normal Hb group was 16%, compared with 50% in the subnormal group (P<0.01). No statistically significant difference in the proportion of functioning grafts or in the serum creatinine levels could be detected. No correlation between EPO treatment and creatinine levels after transplantation was found. The frequency of adverse events was similar in the two groups.

CONCLUSIONS

EPO treatment aimed at reaching a normal Hb in renal transplant recipients reduces the postoperative requirement for blood transfusions and has no deleterious effects on kidney graft function.

Improved hemorheological properties during infusion of a lipid emulsion (Intralipid) in healthy subjects

OBJECTIVES

Lipid emulsions are commonly used for nutrition in critically ill patients. In these patients interventions resulting in deteriorated blood rheology and thereby an impaired microcirculation may be deleterious. This study examined the acute hemorrheological effects of the lipid emulsion Intralipid. We have recently shown that hyperinsulinemia exerts a negative effect on erythrocyte deformability, and here the effect of hyperinsulinemia combined with Intralipid was studied.

SUBJECTS AND INTERVENTIONS

Eleven healthy subjects received Intralipid (200 mg/ml) intravenously as a bolus injection (0.5 ml/kg) over 10 min and thereafter as a continuous intravenous infusion (90 ml/h) for 4 h combined with heparin (200 U/h) to stimulate lipolysis. During the final 2 h an euglycemic hyperinsulinemic clamp was added. Five subjects underwent the same protocol with the exception that saline was given instead of Intralipid and heparin.

MEASUREMENTS AND RESULTS

Whole blood viscosity, plasma viscosity, erythrocyte aggregation tendency and fluidity were measured by rotational viscometry. Compared with basal and control values the Intralipid infusion caused greater erythrocyte fluidity (p < 0.05) and less aggregation tendency (p < 0.05). Whole blood and plasma viscosity remained unchanged. Hyperinsulinemia had no significant effect on the hemorrheological variables measured.

CONCLUSIONS

Intralipid has no deleterious effects on blood rheology in healthy subjects. Instead, it leads to improved erythrocyte aggregation tendency and fluidity. If the emulsion exerts the same effects in patients with impaired circulation, the use of Intralipid may be beneficial in these patients.

Measurement of low frequency magnetic fields from digital cellular telephones

Digital cellular telephones using the GSM (Global System for Mobile Communication) transmit information in bursts of microwaves. This pulsed transmitting mode causes the battery current and currents in the electronics of the apparatus to be pulsed. These pulsed currents produce corresponding pulsed magnetic fields near the phones. A study to determine the magnitude of these fields involved two models of digital telephones. The highest value of the magnetic flux density was 1.8 microT (rms).

Effects of extracorporeal hemapheresis therapy on blood rheology

The blood flow property is one of the factors determining blood perfusion and oxygen supply. The viscosity of the blood is primarily related to the hematocrit, but also to the amount of fibrinogen and other macromolecules present in the blood. Patients with ischemic heart disease have shown a rapid and safe improvement in their hemorheological state when treated with heparin-induced extracorporeal low-density lipoprotein (LDL) precipitation (HELP). In this study we used two extracorporeal hemapheresis methods, plasmapheresis (PP) and immunoadsorption (IA), in 15 patients (eight patients treated with PP and seven patients with IA) with various diseases. Hemorheological variables and plasma fibrinogen were measured before and after the first and before the third treatment performed at 3 consecutive days. The aim of our study was to investigate the immediate effects of these two treatment modalities on the flow properties of blood. Immediately after the first PP and IA session statistically significant declines in plasma fibrinogen concentration, plasma viscosity, whole blood viscosity, and erythrocyte aggregation tendency were found. These changes persisted before the third treatment session. The erythrocyte fluidity and hematocrit remained unchanged. We conclude that extracorporeal hemapheresis therapy, with plasmapheresis or immunoadsorption, affects the blood rheology by decreasing the plasma viscosity and erythrocyte aggregation tendency. The decrease in plasma fibrinogen is probably the main factor underlying that, but other factors such as a decrease in immunoglobulins may also be of importance.

Altered flow properties of blood and increased plasma fibrinogen in cyclosporin-treated renal allograft recipients

BACKGROUND

Abnormalities in blood rheology may be factors contributing to cardiovascular complications and the progression of renal failure in kidney allograft recipients. The haemorheological variables haematocrit, fibrinogen, whole blood viscosity, plasma viscosity, erythrocyte aggregation tendency and fluidity were measured in 27 cyclosporin A (CyA)-treated patients who had received a renal graft at least 6 months previously. Their creatinine clearance was in the range of 12-92 ml/min/1.73 m2 (mean 55+/-19). The values were compared with those obtained from a control group comprising 20 healthy subjects matched according to age, sex and smoking habits.

RESULTS

The haematocrit, plasma fibrinogen, whole blood viscosity, plasma viscosity, erythrocyte aggregation tendency, body mass index (BMI), mean arterial pressure (MAP) and serum triglycerides were increased in the transplanted patients, and the serum high density lipoprotein (HDL)-cholesterol and erythrocyte fluidity decreased. The haemorheological variables were used as dependent variables in a stepwise regression analysis with age, MAP, BMI, urinary albumin excretion rate, blood CyA concentration, creatinine clearance, and serum triglycerides, cholesterol and HDL-cholesterol as independent variables. Plasma fibrinogen was positively correlated with BMI and blood CyA. The whole blood viscosity was positively correlated with blood CyA and negatively with serum HDL-cholesterol. Only serum triglycerides remained correlated with erythrocyte aggregation tendency.

CONCLUSIONS

All variables with a known impact on blood viscosity were altered in the present group of renal transplant recipients. Inappropriate regulation of erythrocyte formation, overweight, the use of CyA, high triglycerides and low HDL-cholesterol levels may be factors contributing to this. The importance of impaired flow properties of blood for the development of cardiovascular diseases and transplant glomerulosclerosis needs to be examined.

Effect of normalization of hematocrit on brain circulation and metabolism in hemodialysis patients

Full correction of anemia with recombinant human erythropoietin (rhEPO) has been reported to reduce the risk of cardiovascular morbidity and mortality and improve the quality of life in hemodialysis (HD) patients. Effects of normalization of hematocrit on cerebral blood flow and oxygen metabolism were investigated by positron emission tomography. Regional cerebral blood flow (rCBF), cerebral blood volume (rCBV), oxygen extraction ratio (rOER), and metabolic rate for oxygen (rCMRO2) were measured in seven HD patients before and after correction of anemia and compared with those in six healthy control subjects. In addition, blood rheology before and on rhEPO therapy was measured in HD patients, which included blood viscosity, plasma viscosity, erythrocyte fluidity, and erythrocyte aggregability. The results showed that plasma viscosity was high (1.51+/-0.19 mPa x s) and erythrocyte fluidity was low (85.8+/-4.8 Pa(-1) x s(-1)), while whole blood viscosity was within the normal range (3.72+/-0.38 mPa x s) before rhEPO therapy. After treatment, the hematocrit rose significantly from 29.3+/-3.3 to 42.4+/-2.2% (P<0.001), accompanied by a significant increase in the whole blood viscosity to 4.57+/-0.16 mPa x s, nonsignificant decrease in erythrocyte fluidity to 79.9+/-7.4 mPa(-1) x s(-1) and nonsignificant change in plasma viscosity (1.46+/-1.3 mPa x s). Positron emission tomography measurements revealed that by normalization of hematocrit, rCBF significantly decreased from 65+/-11 to 48+/-12 ml/min per 100 cm3 (P<0.05). However, arterial oxygen content (caO2) significantly increased from 5.7+/-0.7 to 8.0+/-0.4 mmol/L (P<0.0001), rOER of the hemispheres significantly increased from 44+/-3 to 51+/-6% (P<0.05) and became significantly higher than healthy control subjects (P<0.05). In addition, rCBV significantly increased from 3.5+/-0.5 to 4.6+/-0.6 ml/100 cc brain tissue. The results showed that oxygen supply to the brain tissue increased with normalization of hematocrit, but it was accompanied by increased oxygen extraction in the brain tissue. This may be assumed to be related to the decrease of erythrocyte velocity in the cerebral capillaries as a result of the decreased blood deformability and the increased plasma viscosity.

The haemodynamic response to hyperinsulinaemia in hypertensive subjects

In order to study if the vasodilatory action of insulin is impaired in essential hypertension, 24 untreated patients were challenged with a 2 h euglycaemic hyperinsulinaemic clamp (56 E/m2). Cardiac index (CI) was measured by thoracic impedance cardiography and leg blood flow (LBF) by Doppler ultrasound. During the clamp procedure a significant decline in blood pressure was seen (3.0-5.6% over 120 min, P < 0.001). However, no significant effects on ejection fraction (+6 +/- 8 s.d.%), CI (-1 +/- 2%), heart rate (+2 +/- 1%) or total peripheral resistance (TPRI, -0.5 +/- 2%) were found. LBF increased by 22 +/- 35% (P < 0.005). These haemodynamic effects of insulin were not related to age, sex, body mass index, blood pressure or the insulin-mediated glucose uptake during the clamp. In conclusion, insulin increased LBF, but no changes in CI and TPRI were seen in the hypertensive patients. Furthermore, no association between the ability of insulin to induce vasodilatation and to promote glucose uptake was seen.

The required dose of erythropoietin during renal anaemia treatment is related to the degree of impairment in erythrocyte deformability

BACKGROUND

Renal anaemia is rapidly corrected by recombinant human erythropoietin (rHuEpo) therapy, but the dose required varies greatly. Since impaired erythrocyte deformability may be one factor contributing to the development of renal anaemia, the interrelationship between that variable and the rHuEpo requirement was examined.

METHODS

Twenty-five patients treated with hemodialysis and rHuEpo for at least 6 months were included in the study. The Hb value had been stable and the rHuEpo dose unchanged the last two months. Using a rotational viscometer, the fluidity of erythrocytes, separated from plasma and re-suspended in isotonic buffered saline to a standardized haematocrit, was taken as a measure of erythrocyte deformability.

RESULTS

The average weekly dose of s.c. epoetin alpha was 186 +/- 93 U/kg body weight (range 56-370). The dose was correlated to the reticulocyte fraction (R = 0.69, P = 0.0001). When the rHuEpo dose was used as dependent variable and blood haemoglobin concentration, serum (S) albumin, S ferritin, S aluminium, S PTH, S urea, Kt/V/week, erythrocyte fluidity, and plasma viscosity were used as independent variables in a stepwise multiple regression analysis, only erythrocyte fluidity remained significantly negatively correlated to the rHuEpo dose (R = 0.5, P = 0.01). Despite a tendency towards higher doses of rHuEpo in patients with a C-reactive protein concentration exceeding 20 mg/l, the Hb was lower in these patients.

CONCLUSIONS

We conclude that the interindividual differences in bone marrow response to rHuEpo were small in these patients. Impaired erythrocyte deformability and inflammation seem to be factors associated with increased rHuEpo requirement.

Gender and age differences in transthoracic bioimpedance

Thoracic impedance consists of a constant baseline component Z0 and a time-variable component delta Z which represents the impedance change related to the cardiac cycle. The maximum part of delta Z [(dZ/dt)max] represents the peak of the ascending aortic blood flow. Measurements of basal thoracic impedance are affected by structural and anatomical differences in the thorax related to sex and ageing. This component is a variable in the denominator of Sramek's formula which is used for calculating stroke volume. The aim of this study was to elucidate the question as to whether the age- and sex-related variation in basal impedance may affect bioimpedance measurements of stroke volume. The study comprised 111 healthy subjects (55 males and 56 females) of ages between 20 and 69 years, divided according to age decades into five groups each of males and females. Stroke volume index (SI), Z0 and (dZ/dt)max were measured in every subject, using transthoracic bioimpedance cardiography. Z0 and (dZ/dt)max had significantly higher values in females than in males in every age group except the oldest one in the case of Z0 and the oldest two groups in the case of (dZ/dt)max. Stroke index showed no significant sex difference, although the higher Z0 in females may underestimate the values of stroke index. Elevation of (dZ/dt)max in females may therefore reflect a positive relation to Z0 rather than higher flow rates. Since Z0 and (dZ/dt)max are variants in opposite positions in Sramek's formula (denominator and numerator, respectively), this functional relationship may keep the bioimpedance measurements from being affected by the sex- and age-related changes in Z0.

Anemia associated with advanced prostatic adenocarcinoma: effects of recombinant human erythropoietin

BACKGROUND AND METHODS

Nine patients with hormone-refractory metastatic prostatic adenocarcinoma and anemia were treated with recombinant human erythropoietin (rHuEpo) at a median dose of 150 U/kg BW 3 times a week subcutaneously. Baseline hemoglobin (Hb) ranged from 70 to 116 g/L, and the study duration was 12 weeks (median patient participation period was 8 weeks).

RESULTS

Four patients demonstrated a median Hb increase of 20 g/L and were considered responders. Three patients showed a median increase of 17 g/L but required blood transfusion once, and were therefore considered as partial responders. Baseline erythropoietic status showed a significant correlation between serum Epo and Hb. Inadequate Epo production, evaluated by the observed/predicted log Epo ratio, was found in two patients. Defective bone marrow activity, demonstrated by low transferrin receptor (TfR), and hypoferremia in spite of abundant iron stores were also shown. Hemorheological investigations showed elevated plasma viscosity.

CONCLUSIONS

Our results indicate that suppression of erythropoiesis can be mainly explained by the depressed marrow activity. The altered hemorheology might contribute to the anemia. This anemia could possibly be corrected with rHuEpo.

Effects of LDL apheresis on blood rheology in two patients with homozygous familial hypercholesterolaemia

Changes in haemorheological and lipid variables were investigated in 2 patients with homozygous familial hypercholesterolaemia (FH) treated with low-density lipoprotein (LDL) apheresis using dextran sulphate adsorbent. The immediate effect of LDL apheresis was a fall in plasma fibrinogen by 50%, total and LDL cholesterol by 60%, plasma viscosity by 12% and whole blood viscosity by 17%. Before the 12th treatment session, plasma fibrinogen concentration remained reduced by 22%, whole blood viscosity by 17% and the plasma viscosity by 11% compared with the initial values. Total and LDL cholesterol in plasma also remained reduced by about 50%. We conclude that LDL apheresis, using dextran sulphate adsorbent, improves blood rheology. The decrease in plasma fibrinogen concentrations, plasma viscosity and LDL cholesterol might be factors contributing to the improved haemorheological properties.

Renal anaemia treatment with recombinant human erythropoietin increases cardiac output in patients with ischaemic heart disease

An increase in blood pressure is common during treatment of renal anaemia with recombinant human erythropoietin (rhEPO). Concomitant findings of a decrease in cardiac output indicate that an increase in the peripheral flow resistance underlies the increase in blood pressure. The aim of this study was to elucidate the haemodynamic changes during rhEPO treatment in patients with ischaemic heart disease (IHD). Haemodynamic variables were assessed by impedance cardiography in 18 consecutive patients with renal anaemia before and after rhEPO treatment. IHD was found in eleven of these patients. The remaining seven served as controls. Before rhEPO treatment, the cardiac index was decreased in the group of patients with IHD, compared with controls and healthy subjects. Due to an increase in stroke index, the cardiac index increased during rhEPO treatment and reached values equal to those in the control group. The blood pressure increased and the increase in mean arterial pressure was correlated to the increase in cardiac index. Apparently the patients with IHD were unable to compensate for anaemia by increasing their cardiac index. Anaemia treatment increased cardiac index, which in turn caused an increase in blood pressure in these patients.

Decreased blood viscosity and serum levels of erythropoietin after anti-hypertensive treatment with amlodipine or metoprolol: results of a cross-over study

The increased viscosity of blood of hypertensive patients can be assumed to be a risk factor for the development of cardiovascular diseases. The aim of the present study was to elucidate whether anti-hypertensive treatment has any impact on blood rheology. Twenty patients with previously untreated hypertension who consecutively attended our outpatient hypertension clinic were included in this prospective, open, cross-over study. The patients were randomly selected to treatment with amlodipine or metoprolol. The anti-hypertensive therapy was switched after 4 months. Haemorheological and haemodynamic variables were measured with rotational viscometry and impedance cardiography, respectively. Fifteen and 16 patients could be evaluated after amlodipine or metoprolol treatment respectively. The mean blood pressure (BP) decreased from 159 +/- 22/105 +/- 7 to 139 +/- 21/91 +/- 6 mm Hg on amlodipine and from 162 +/- 22/104 +/- 5 to 145 +/- 24/90 +/- 8 mm Hg on metoprolol therapy. After amlodipine treatment, the total peripheral resistance index decreased whereas metoprolol treatment was accompanied by a decrease in the cardiac index. Decreases in whole blood viscosity, haematocrit and serum erythropoietin were found after amlodipine as well as metoprolol treatment. After amlodipine the plasma viscosity decreased and the erythrocyte deformability increased in the majority of patients. Plasma fibrinogen decreased after metoprolol treatment. Despite the differences in haemodynamic mechanisms underlying the decrease in BP, amlodipine and metoprolol exert beneficial effects on blood viscosity. Haemodilution and a decrease in serum erythropoietin may be factors underlying this decrease in blood viscosity.

Treatment of renal anaemia with recombinant human erythropoietin results in decreased red cell uptake of 45Ca

The ability of erythrocytes to undergo deformation may be of importance to erythrocyte survival and to blood flow resistance. In a previous study a decreased deformability was demonstrated in the erythrocytes of uraemic patients treated with recombinant human erythropoietin (rhEPO). Erythrocyte deformability is, at least partly, determined by the intracellular concentration of free calcium ions. Six patients with renal anaemia (initial haemoglobin 95 +/- 11 g/l) were treated with rhEPO. They were examined with regard to certain erythrocyte characteristics before treatment and after reaching a haemoglobin concentration exceeding 120 g/l. A decrease was noted upon treatment in erythrocyte deformability and uptake of 45Ca in vitro. The blood pressure tended to increase. The individual values of the decrease in 45Ca uptake and the increase in systolic blood pressure were positively correlated to each other (r = 0.87; p < 0.05). No correlation was found between changes in erythrocyte deformability and 45Ca uptake. The decrease in 45Ca uptake may be interpreted in two different ways. It could reflect a reduced membrane permeability to calcium ions, or, which is more probable, it could be the end result of an increase in the intracellular metabolic pool of free calcium ions caused by the rhEPO treatment. We, therefore, conclude that rhEPO treatment has certain effects on calcium homeostasis in erythrocytes which may be related to blood pressure regulation.

Blood viscosity and peripheral vascular resistance in patients with untreated essential hypertension

OBJECTIVES

The viscosity of blood is increased in patients with essential hypertension. The aim of the present study was to investigate the importance of the different variables of blood rheology to total peripheral resistance, and to elucidate whether inappropriate regulation of the formation of erythropoietin could be important.

DESIGN

Nineteen consecutive patients with untreated essential hypertension were examined and compared with a group of matched healthy volunteers.

METHODS

The haemorheologic variables were assessed by rotational viscometry and the haemodynamic variables by bioimpedance cardiography. The serum concentrations of erythropoietin were determined by radioimmunoassay.

RESULTS

The whole blood viscosity and peripheral resistance index were elevated in the hypertensive group. The two variables were positively correlated with each other (r = 0.68, P = 0.0015). The plasma viscosity and erythrocyte aggregation tendency were increased and the erythrocyte deformability, measured as fluidity, was decreased in the hypertensive patients. In the male subpopulation (n = 12) the aggregation tendency was positively, and the deformability negatively, correlated with body mass index. The serum concentrations of erythropoietin were equal in the two groups.

CONCLUSIONS

The increased total peripheral resistance in patients with essential hypertension may in part be explained by an increased blood viscosity, but the possibility of an opposite cause-effect relationship must also be taken into consideration. The haemorheological abnormalities observed in the present patients cannot be explained by high serum levels of erythropoietin.

Reduced oxygen affinity contributes to improved oxygen releasing capacity during erythropoietin treatment of renal anaemia

In addition to haemoglobin concentration, haemoglobin oxygen affinity plays a major role in the oxygen releasing capacity of the blood. In this study we have measured oxygen affinity as P50 and calculated the oxygen releasing capacity of blood from 10 haemodialysis patients treated with erythropoietin (rHuEpo). The patients were examined with different assays before start of treatment, after 11 weeks, and after 27 weeks. During the first phase of treatment the oxygen releasing capacity improved because of an increase in the haemoglobin concentration and P50. During the second phase there was a further significant increase in haemoglobin concentration, but due to a decrease in the P50 value the oxygen releasing capacity remained unchanged. Despite an unchanged oxygen releasing capacity and total blood volume, the antihypertensive treatment had to be increased during that phase of treatment. An increase in whole-blood viscosity may explain the increased need of antihypertensive drugs. The increase in P50 during the first phase of rHuEpo treatment can probably be explained by decreased mean age of the erythrocyte population and implies that the beneficial effect is greater than could be concluded from the increase in haemoglobin concentration.

Impaired erythrocyte fluidity during treatment of renal anaemia with erythropoietin

Seventeen haemodialysis patients with renal anaemia were treated with recombinant human erythropoietin (rhEPO) and observed for 30 weeks. The viscosity of whole blood and plasma, the erythrocyte aggregation tendency, and the erythrocyte deformability, measured as fluidity, were analysed every second week. All patients responded with increasing haematocrit and whole-blood viscosity. The plasma viscosity and the erythrocyte aggregation tendency were already increased before the start of treatment, and remained unchanged during treatment. The basal erythrocyte fluidity tended to be impaired, although not significantly so. During treatment, significant impairment of fluidity was observed at the beginning of the treatment period. After 24 weeks the fluidity started to increase, and it later reached values observed before the start of treatment. Hence, the quality of the erythrocytes formed during the corrective phase of rhEPO treatment differs in some respects from that of cells formed at a normal production rate. The impaired fluidity might have important implications for the flow resistance in small vessels, and contribute to the development or aggravation of hypertension that is often seen during rhEPO treatment.

Outcome of renal transplantation in patients treated with erythropoietin

The introduction of treatment with recombinant human erythropoietin (rhEPO) has raised the possibility of deleterious effects on early kidney graft function. Due to renal anemia, the great majority of patients waiting for kidney transplantation until now have had a low hematocrit. It has been suggested that a low hematocrit is beneficial for early kidney graft function by protecting the transplanted kidney from so-called reperfusion damage, which results in delayed onset of renal function. We have retrospectively examined the early function of 26 kidney grafts transplanted to uremic patients with rhEPO corrected anemia. Compared with a randomized control group no significant differences were seen in the rate of immediate onset of graft function, graft survival or serum levels of creatinine one year after transplantation. We conclude that the reversing of anemia by rhEPO in recipients of cadaver kidneys does not impair early graft function.