Short-term growth hormone treatment and microcirculation: effects in patients with chronic kidney disease.

Endothelial dysfunction is common in patients with chronic kidney disease (CKD) and contributes significantly to the high long-term cardiovascular morbidity and mortality. The short-term cardiovascular effects of recombinant human growth hormone (rhGH) in CKD patients (stages III-V) and healthy controls (n=15 each) were explored in a single-center, non-randomized pilot study. Subjects were investigated before, after a 7 day treatment with rhGH, and after a 7 day wash-out period. Microcirculation was assessed by nailfold capillaroscopy and leg strain gauge plethysmography. Echocardiography was performed and serum concentrations of IGF-I and IGF-binding protein-3 (IGFBP-3) were determined. Before the start of rhGH therapy, mean post-ischemic maximum flow velocity of erythrocytes (V(RBC)) and leg blood flow (LBF) in CKD patients were significantly reduced to 68% and 75% of that seen in controls, whereas V(RBC) and LBF under resting conditions were comparable. Treatment with rhGH significantly increased V(RBC) and LBF under resting conditions. Whereas maximum post-ischemic V(RBC) was improved by rhGH in patients and controls, maximum post-ischemic LBF increased in controls only. This was paralleled by a non-significant reduction of total vascular resistance, and increased heart rate and cardiac index. In conclusion, CKD patients respond to short-term rhGH treatment with significantly improved capillary blood flow, whereas only minor effects on total peripheral resistance and cardiac output were noted.

Changes in lymphocytic cluster distribution during extracorporeal immunoadsorption.

The success of apheresis treatment is often measured as a decrease in the detected antibodies and an improvement in different disease-related scores. Sometimes, however, the seriousness of the disease does not correlate with the antibody level. During a period of 8 years, 15 patients (3 myasthenia gravis, 1 multiple sclerosis, 2 systemic lupus erythematosus, 3 alloimmunized kidney transplant, 6 rheumatoid arthritis) were treated by protein A immunoadsorption. Lymphocyte subpopulations (activated T cells, cytolytic T cells, B cells, natural killer cells) and inflammatory proteins (ferritin, C-reactive protein, alpha1-antitrypsin, alpha2-macroglobulin) were analyzed. After observing clinical outcomes, the patients could be divided into 2 groups, respectively: Group 1, responding patients with remission of disease; and Group 2, delayed-responding patients, who required chronic treatment. Group 1 patients characteristically showed a greater increase in activated T and cytolytic T cells which correlated with a greater decrease of B cells. It might be possible that protein A immunoadsorption induced immunomodulation. Further immunological investigation is required to verify these findings.

Online hemodiafiltration versus acetate-free biofiltration: a prospective crossover study.

Online hemodiafiltration (online HDF) and acetate-free biofiltration (AFB) are 2 innovative renal replacement therapies. Convincing evidence has shown that both techniques are superior to conventional hemodialysis in many aspects. The aim of the present investigation was to compare online HDF and AFB in 12 stable maintenance hemodialysis patients in a prospective, randomized crossover trial. Twelve stable dialysis patients, age 49.7 +/- 11.3 years and on dialysis for 83.5 +/- 76.7 months, were treated prospectively and randomly by either AFB, predilution HDF (pre-HDF), or postdilution HDF (post-HDF) for a total of 36 weeks using exclusively F60S high-flux dialyzers. Routine blood biochemical tests, bone metabolism parameters, and clearance for both small and larger molecular weight substances were measured at defined intervals. During the trial period inter- and intradialysis symptoms, e.g., hypotensive episodes and intradialysis arterial blood gas analyses, were recorded. Both online HDF and AFB were well accepted by the overwhelming majority of patients and also by the dialysis staff. Pretreatment sodium, total and ionized calcium, chloride, bicarbonate, and urea did not differ within or between the 3 treatment groups. Potassium increased slightly in HDF patients while phosphate and beta2-microglobulin (beta2-M) decreased in all groups. After dialysis, AFB patients exhibited a significantly higher bicarbonate concentration and lower potassium level when identical potassium concentrations in dialysate were used. Patients receiving AFB manifested less intradialysis partial pressure of oxygen drop and partial pressure of carbon dioxide rise than those on HDF treatments. HDF treatments could afford higher single-pool and double-pool Kt/V, higher effective urea and beta2M clearance, and lower total interdialysis symptom scores than the AFB treatment method. While bone metabolism parameters did not differ between the 3 dialysis modalities, some parameters such as deoxypyridinoline in HDF and osteocalcin, pyridinoline, and deoxypyridinoline in AFB deteriorated at the end of the crossover study. Aluminum concentration decreased progressively to about one-third of prestudy values at the end of the study with all 3 treatments. AFB was associated with a lower predialysis mean arterial pressure (MAP), a smaller drop in MAP during treatment, and similar hypotension episodes compared with the 2 HDF treatments. Albumin concentration showed a trend to decrease during the first 2 months of the trial period followed by a slight increase thereafter but still significantly lower than initial value at the end of crossover. Both online HDF and AFB share most of the features of optimal renal replacement therapy. Online HDF is superior to AFB in such aspects as increased delivered dialysis dose both for small and larger molecular weight toxins and less interdialysis symptoms. On the other hand, AFB is associated with a smaller effect on arterial blood gas values and improved intradialysis hemodynamic tolerance. Some dialysis-related symptoms and complications in the case of our AFB practice could be attributable, at least in part, to low dialysate calcium level.

Comparison of two filter combinations for low-density lipoprotein apheresis by membrane differential filtration: a prospective crossover controlled clinical study.

Membrane differential filtration is an accepted procedure for the extracorporeal removal of low-density lipoprotein (LDL). Reduction rates largely depend on the nature of the membranes and are ideally evaluated in a crossover study design. Four patients who had been treated by LDL apheresis for at least 6 months were included. Six consecutive weekly sessions (40 ml plasma/kg body weight) were scheduled per system (Plasmacure PS06/Evaflux Eval 5A [Kuraray] versus Plasmaflo OP05W/Cascadeflo AC1770 [Asahi]). Laboratory measurements indicated reductions of plasma concentrations for fibrinogen (37% [Kuraray] versus 44% [Asahi]), IgG (15% versus 20%), IgA (24% versus 28%), IgM (63% versus 53%), and total protein (11% versus 16%). Total cholesterol was eliminated by 52% versus 49%, LDL by 67% versus 66%, triglycerides by 56% versus 41%, and high-density lipoprotein by 10% versus 20%. Three therapies employing the Asahi filter combination were terminated prematurely due to saturation of the plasma fractionator. In conclusion, despite similar physical properties, the membranes differ significantly concerning selectivity and sensitivity to saturation.