Dosing strategies for conversion of haemodialysis patients from short-acting erythropoiesis stimulating agents to once-monthly C.E.R.A.: experience from the MIRACEL study.

AIMS: To analyse the impact of dosing decisions for continuous erythropoietin receptor activator (C.E.R.A.), a continuous erythropoietin receptor activator. METHODS: This was a prospective, multicentre, single-arm study in haemodialysis patients receiving epoetin alfa/beta or darbepoetin alfa. After a 2-month screening phase, patients were converted to monthly C.E.R.A. using pre-filled syringes during a 5-month titration phase and a 2-month evaluation phase. RESULTS: Four hundred and twenty-four eligible patients were converted to C.E.R.A. Mean Hb were 11.7 ± 0.7, 11.7 ± 0.8 and 11.5 ± 0.8 g/dl during screening, titration and evaluation, respectively. C.E.R.A. starting dose was 125 µg (n = 311) or 200 µg (n = 106), with corresponding final doses of 129 ± 61 µg and 203 ± 58 µg. The mean number of C.E.R.A. dose decreases and increases were 0.9 ± 1.0 and 1.1 ± 1.0 per patient, respectively. Hb rarely exceeded 12.5 g/dl after a C.E.R.A. dose increase (< 8%) and remained ≥ 11 g/dl after a dose reduction on approximately three-quarters of occasions. Among the 53 occasions where Hb decreased ≥ 2 g/dl between two consecutive visits, the previous dose had been withheld (n = 9), concomitant blood loss, coagulopathy or infection was present (n = 13), or iron parameters were low (n = 17). There were 104 adverse events/month during screening, and 45/month during the titration/evaluation phases. Serious adverse events occurred in 18.0 and 21.0 patients/month during the screening and titration/evaluation phases, respectively. CONCLUSION: Switching haemodialysis patients from shorter-acting ESA to once-monthly C.E.R.A. using pre-filled syringes is straightforward, and Hb levels remain stable. Starting dose recommendations and dose changes correlated well with the clinical setting. Collateral factors such as infection or aggravating concomitant medical conditions should be taken into account.

Dialysis membrane-dependent removal of middle molecules during hemodiafiltration: the beta2-microglobulin/albumin relationship.

AIM: Current hemodialysis therapy modalities such as online hemodiafiltration (HDF) attempt to enhance solute removal over a wide molecular weight range through a combination of diffusion and convection. While the effects of variations of treatment modalities and conditions have been studied reasonably well, few studies have examined the efficacy of HDF to remove middle molecules in relation to the dialyzer and membrane characteristics. In this investigation, diverse high-flux dialyzers, covering a wide range of membrane permeabilities, were compared under identical in vivo conditions to assess their ability to eliminate larger uremic retention solutes (using beta2-microglobulin as a surrogate of middle molecules) without simultaneously causing excessive leakage of useful proteins such as albumin. PATIENTS AND METHODS: In a prospective, crossover study, 3 ESRD patients were treated with 8 different brands of high-flux dialyzers at 4 different ultrafiltration (UF)/substitution flow rates (QS: 0, 30, 60, 90 ml/min) in post-dilution HDF mode. Thus, each patient underwent 32 treatment sessions, with a total of 96 treatment sessions conducted during the entire clinical study. Albumin and beta2-microglobulin levels were measured in both, dialysate and blood. Both, albumin and beta2-microglobulin elimination was dependent upon the permeability of the dialysis membrane as well as on the ultrafiltration/substitution flow rates applied. RESULTS: At the maximum UF rate of 90 ml/min, the total albumin loss (measured in the dialysate) ranged from 300 mg/4 h (for the FLX-15 GWS dialyzers) to 7,000 mg/4 h (for the BS-1.3U dialyzers). Up to 50% reduction of albumin occurred within the first 30 minutes of the dialysis treatment, and the leakage of albumin increased exponentially with increasing UF rates as well as increasing transmembrane pressure (TMP). The various dialyzers could be classified according to their UFR-dependent beta2-m reduction rates (RR), into low (< 50%; FLX-15 GWS, CT 150G), medium (50-70%; Polyflux 14 S, BLS 814SD, H4) and high (> 70%; BS-1.3U, APS 650, FX 60) removers of middle molecules. One dialyzer type (CT 150G) showed extremely low beta2-m RR and relatively high albumin losses. Most membranes, however, showed either low albumin leakage coupled with low beta2-m removal, or high beta2-m RR but at the expense of considerable albumin leakage. Only 2 membrane types approached the desired balance between high to medium beta2-m RR while simultaneously restricting the albumin leakage especially at higher filtration/substitution rates. CONCLUSION: Our investigations demonstrate that not all dialysis membranes classified as "high-flux" are comparable in their ability to specifically and efficiently remove middle molecules, or curtail the unwanted excessive leakage of essential proteins from the patient's blood. Thus, the selection of appropriate high-flux dialyzers for specific patient requirements should be based more upon clinical evaluations and analyses rather than on product specifications alone.

Release of microparticles in LDL apheresis.

Particle contamination of blood always takes place in extracorporeal systems and few studies have been conducted to evaluate potential risks. Particle concentration was measured in the efferent blood line on original equipment for two established LDL elimination procedures (DALI) (Fresenius) and Liposorber (Kaneka). Acquired data were compared with standards for infusion solutions from European (EP) and American (USP) Pharmacopoeia. All values were well below the given limits. Even in extreme situations (>20 pump stops) particle concentration did not exceed the standards. Considering an average treated blood volume of 7.31 for the DALI-System and 17.01 for Liposorber (long term clinical studies) the absolute amount of particles infused per treatment was 167,000 (DALI) and 465,000 (Liposorber) particles > or = 2 microm.

The outcome in myasthenia gravis patients--an eight-year follow-up after finishing immunoabsorption therapy.

Eight years ago four patients suffering from myasthenia gravis (MG) type C and E according to Compston with failed drug therapy were treated three times (one patient 11 times) by protein A immunoabsorption (Immunosorba, Excorim, Fresenius Hemocare GmbH, StWendel, Germany). No further immunoabsorption treatments have been carried out. In addition, three patients were given a thymectomy. The present status of the patients was checked six and eight years thereafter. We could see a beneficial effect in all MG patients. The patients are fit for work; all have an improved Besinger index. The patients were used as their own controls. A higher anti-AChR-ab level six years after protein A immunoabsorption than at the beginning was seen in all patients combined with a less serious MG. In addition, their immunomodulation could be induced as seen in lymphocyte and inflammatory protein changes during the first 36 days after beginning immunoabsorption treatment. A larger population has to be investigated to verify these results.

On-line hemodiafiltration with pre- and postdilution: a comparison of efficacy.

Since the introduction of on-line substituate preparation, high substituate rates (Qs) in pre- and postdilution for hemodiafiltration (HDF) procedures can be realized. During postdilution HDF (POD-HDF) and additional convective removal is possible, but in vivo Qs is limited to approx. 1/3Qb (bloodflow). With predilution HDF (PRD-HDF) higher Qs and therefore high convective transport rates by ultrafiltration can be reached. On the other hand the blood concentration is diminished by predilution. Further decrease of the diffusive transport is caused by reduced dialysate flow Qd due to separation of the substituate from the dialysate (Fresenius 4008 On-Line HDF, Gambro AK100 Ultra). The theoretical description of the combined diffusive-convective transport is limited to 1-dimensional models and small UF-rates. Therefore for practical and theoretical purposes the assessment of the efficacy of on-line PRD-HDF and POD-HDF in different molecular weight ranges is desirable. By means of in vitro experiments the effective clearances Keff of hemodialysis (HD, dialyzer: Fresenius F60) for urea, creatinine, vitamin B12 and inulin were compared with measured and theoretical Keff of POD- and PRD-HDF. The theoretical expectation is confirmed that Keff for small molecular weight substances decreases slightly with PRD-HDF and increases for larger molecules. In the case of POD-HDF Keff for small molecular weight substances increases slightly and strongly for larger molecules. In vivo experiments were performed to measure the real substance removal from patient's blood and to figure out the impact of dialysate flow (collection of the used dialysate during the 1. treatment hour and concentration measurements for urea, creatinine, phosphate, beta 2-MG). The results show that the subtraction of Qs from Qd reduces Keff for urea, creatinine and phosphate but not for beta 2-MG. PRD-HDF with Qd = 500 ml/min is significantly less effective for small molecules than HD. There is no significant difference of Keff for urea, creatinine, phosphate during HD and PRD-HDF with Qd = 800 ml/min, but a significant increase of 10-15% for POD-HDF. Keff for beta 2-MG increases by 75% for PRD-HDF and 95% for POD-HDF compared with HD (Qd = 500 ml/min).

On-line hemodiafiltration with pre- and postdilution: impact on the acid-base status.

With on-line formation of the substitution fluid, high substitution rates in predilution (PRD) and postdilution (POD) can be obtained (Fresenius 4008 On-Line HDF; Gambro AK 100 Ultra). The substitution fluid is branched off from the dialysate produced by the dialysate delivery system of the HDF machine. Under these conditions it is desirable to consider the effect of the different treatment modes on the acid-base status. Using Fresenius 4008 On-Line HDF machines, ESRD-patients were treated alternately with high-flux hemodialysis (HD), postdilution HDF (POD-HDF) and predilution HDF (PRD-HDF), while all other treatment parameters were kept constant, in particular the bicarbonate dialysate concentration. Plasma-HCO3, -pH and -pCO2 were measured and compared with the results of a multicompartment bicarbonate model developed by Thews. Also plasma-pO2 and K+ were measured. The results showed no significant differences between HD, POD- and PRD-HDF. Acidosis was corrected effectively and no excessive compensation of the acid-base disturbance was observed.

Choledochal cyst with perforation--an unusual presentation. Case report and review of the literature.

A unique case of a 22-month-old baby girl with a perforated choledochal cyst, who presented with vague abdominal symptoms but without any jaundice, an acute abdomen and an incidental finding of acholic stools, is described below with a review of the literature.

Evaluation of maintenance of stable haemoglobin levels in haemodialysis patients converting from epoetin or darbepoetin to monthly intravenous C.E.R.A.: the MIRACEL study.

BACKGROUND AND OBJECTIVES: C.E.R.A., a continuous erythropoietin receptor activator, offers once-monthly dosing without compromising haemoglobin control. This study was undertaken to examine whether monthly C.E.R.A. using pre-filled syringes maintains stable haemoglobin levels when administered according to local clinical judgement. RESEARCH, DESIGN AND METHODS: MIRACEL was a prospective, open-label, single-arm, multicentre study performed at 90 nephrology centres in Germany. After a 2-month screening phase, haemodialysis patients receiving epoetin or darbepoetin were converted to monthly intravenous C.E.R.A., with a 5-month titration phase followed by a 2-month evaluation phase. CLINICAL TRIAL REGISTRATION: Clinicaltrials.gov: NCT00413894 RESULTS: Of 661 patients screened, 424 (64.1%) started C.E.R.A. therapy (previous treatment: 72.2% epoetin, 27.8% darbepoetin); 416 were eligible for inclusion in the intent-to-treat population. A mean of two C.E.R.A. dose changes were required during the 7-month treatment period. The primary efficacy variable, haemoglobin within 11-12.5 g/dL or 10-13 g/dL during the evaluation phase, was achieved in 109 (30.8%) and 265 (74.9%) of the 354 evaluable patients, respectively, with no differences observed between patients formerly receiving epoetin or darbepoetin or different dosing frequencies. During the screening, titration and evaluation phases, mean haemoglobin was 11.7 +/- 0.7 g/dL, 11.6 +/- 0.9 g/dL and 11.4 +/- 1.0 g/dL, respectively, and 90.6% (377/416), 70.4% (293/416) and 82.9% (345/416) of patients exhibited < or = 1 g/dL change from phase-specific individual means. C.E.R.A. was well-tolerated with a safety profile similar to that reported in phase III studies. CONCLUSIONS: In this single-arm, open-label, multicentre study, conversion of a large population of haemodialysis patients from epoetin or darbepoetin to monthly C.E.R.A. administration using pre-filled syringes was shown to be practical, convenient and offer good control of haemoglobin levels, regardless of the previous type of therapy or dosing frequency.

Extracorporeal removal of circulating immune complexes: from non-selective to patient-specific.

The classical immune complex-mediated disease, termed serum sickness, developed a short time after the injection of horse anti-tetanus toxin. Antibodies against circulating horse plasma proteins lead to the formation of immune complexes within the blood circulation (CIC). The inflammatory response, including systemic complement activation and vasculitis, seriously affected the function of all organs, including the most susceptible kidney. Meanwhile CIC have been detected in almost every systemic disease, including autoimmune disorders and also cancer and infections. This brief review will focus on the rationale and the equipment for extracorporeal elimination of CIC.

Immunoadsorption of immunoglobulins alters intracytoplasmic type 1 and type 2 T cell cytokine production in patients with refractory autoimmune diseases.

Intracellular cytokine staining and flow cytometry were used to investigate whether immunoadsorption (IA) of immunoglobulins alters intracytoplasmic cytokine production in CD4+ and CD8+ T cells from the blood of patients with refractory rheumatoid arthritis (n = 7), membrane proliferative glomerulonephritis (n = 1), and Goodpasture's syndrome (n = 1). Four patients (Group 1) showed severely depressed production of TNF-alpha, IL-2, IFN-gamma, and IL-4 by CD4+ and CD8+ T cells and responded to 3 IA sessions with significant increases in CD4+TNF-alpha+, CD4+IL-2+, and CD8+IL-2+ T cells. Also, a tendency toward increased percentage levels of CD4+ T cells producing IFN-gamma or IL-4 and of CD8+ T cells producing either TNF-alpha or IFN-gamma was seen, but due to the small number of patients investigated, these differences did not attain statistic significance. Group 2 (n = 5) showed unimpaired intracellular cytokine levels and responded to IA with a heterogeneous pattern of changes in TNF-alpha, IL-2, IFN-gamma, and IL-4 production, but these alterations were smaller than those in Group 1. The present findings indicate that the extracorporeal removal of immunoglobulins by anti-IgG or protein A adsorber columns has an impact on T cell immunity and suggest that modulating effects on cellular immune system function are involved in the mode of action of IA.

Particle release in extracorporeal low-density lipoprotein lowering therapies.

Release of microparticles into the blood during extracorporeal circulation must be kept low because of possibly serious acute and chronic adverse effects. Concentration and size distribution of microparticles were measured during simulated treatments (n = 7) on original equipment for 2 standard low-density lipoprotein (LDL) elimination procedures (DALI 750, Fresenius AG, St. Wendel, Germany and Liposorber, Kaneka Corporation, Osaka, Japan) and compared to hemofiltration solutions. For both systems as well as in hemofiltration solutions, the mean particle concentrations in 500 ml portions gathered from the efferent blood line stayed below 10% of pharmacopoeia standards for infusion solutions (United States Pharmacopoeia, European Pharmacopoeia) in all measured size classes. Although particle concentrations were comparable in all systems, the mean total number of particles > or =2 microm released per session was lowest in the DALI (167,000) compared to the Liposorber (465,000) and hemofiltration solutions (2,240,000). This was mainly due to different total processed blood volumes necessary to achieve the required LDL reduction.

Two cases of refractory endocrine ophthalmopathy successfully treated with extracorporeal immunoadsorption.

Endocrine ophthalmopathy (EO) is a severe disease entity that is characterized by retrobulbar swelling due to accumulation of glycosaminoglycans on an autoimmune basis. This disorder can lead to the loss of vision and often is resistant to conventional therapy. There is a relation to Graves' hyperthyroidism, but probably no close association. Two patients with severe EO that was resistant to usual therapeutic approaches including steroids and radiological and surgical measures underwent a 20 session course of intensive immunoadsorption therapy (Plasmaselect/Therasorb Anti-IgG) with a mean 2- to 3-fold plasma volume treated. After the first sessions, both patients voiced an impressive relief of their major symptoms, which was confirmed by ophthalmological investigation. Throughout the time of therapy until present, these patients have remained at their respective levels of improvement. We consider immunoadsorption an effective therapeutic opportunity in severe EO resistant to conventional treatment.

Therapeutic apheresis in myasthenia gravis patients: a six year follow-up.

Six years ago 4 patients suffering from myasthenia gravis (MG) types C and E according to Compston with failed drug therapy were initially treated 3 times (1 patient, a total of 11 times) by protein A immunoadsorption (Immunosorba, Excorim AB, Lund, Sweden). No further immunoadsorption treatments have been carried out. In addition, 3 patients were given a thymectomy. The present status of the patients was checked. We could see a beneficial effect in all MG patients. The patients are fit for work; each has an improved Besinger index. The patients were used as their own controls. A higher anti-AChRAb level 6 years after protein A immunoadsorption than at the beginning was seen in all patients, combined with less serious MG. In addition, their immunomodulation could be induced as seen in lymphocyte and inflammatory protein changes during the first 36 days after beginning immunoadsorption treatment. A larger population has to be investigated to verify these results.