Mana Yahiro

Hepcidin as well as TNF-α are significant predictors of arterial stiffness in patients on maintenance hemodialysis

BACKGROUND Dysregulated iron metabolism has been suspected to be linked to anemia of chronic disease and to cardiovascular disease (CVD). For the purpose of clarifying the factors affecting arterial stiffness, we evaluated the relationship between iron metabolism, brachial-ankle (ba)-pulse wave velocity (PWV) and several risk factors for CVD in maintenance hemodialysis (MHD) patients. METHODS A total of 168 MHD patients were recruited, and the levels of iron parameters, hepcidin, CVD risk factors and ba-PWV were evaluated. The level of serum hepcidin-25 was specifically measured by liquid chromatography-tandem mass spectrometry. RESULTS Serum levels of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and hepcidin were higher in MHD patients, which was consistent with results from our previous study. ba-PWV significantly correlated with age (P < 0.01, R = 0.34), total cholesterol (T-CHO; P = 0.02, R = 0.21), TNF-α (P < 0.01, R = 0.24) and hepcidin (P < 0.01, R = 0.25) but not with other iron parameters and CVD risk factors. According to multiple regression analysis, age (β = 0.30), T-CHO (β = 0.24) TNF-α (β = 0.19) and hepcidin (β = 0.23) were selected as the significant predictors of ba-PWV in MHD patients. CONCLUSION Serum levels of both hepcidin and TNF-α are independently associated with arterial stiffness in MHD patients, suggesting that microinflammation and iron metabolism might affect the integrity of arterial walls.

Therapeutic efficacy of double filtration plasmapheresis in patients with anti-aquaporin-4 antibody-positive multiple sclerosis

Multiple sclerosis (MS) in Asian countries, including Japan, is classified into two types: conventional MS (C-MS), characterized mainly by cerebral lesions, and opticospinal MS (OS-MS) or neuromyelitis optica (NMO), characterized by selective involvement of the optic nerve and spinal cord. Recently, a serum immunoglobulin-G-antibody was discovered in patients with NMO that targets aquaporin-4 (AQP4). The existence of the anti-AQP4 antibody shows the pathogenetic role of humoral immune factors in OS-MS/NMO. We treated eight patients with anti-AQP4 antibody-positive MS with double filtration plasmapheresis (DFPP) to remove the antibody. Improvement of vision was observed in two patients. Motion improvement was seen in seven patients. Sensory improvement was observed in four patients. In total, six out of eight patients (75%) showed therapeutic improvement after DFPP treatment. We propose that DFPP might be an effective therapeutic option for patients with anti-AQP4 antibody-positive MS.

Effects of acetate-free citrate-containing dialysate on metabolic acidosis, anemia, and malnutrition in hemodialysis patients.

Previously, dialysate contained small amounts of acetate as an alkaline buffer. Recently, acetate-free dialysate (A[-]D) has been available. We evaluated the clinical effect of A(-)D over acetate-containing dialysate (A(+)D) on acid-base balance, anemia, and nutritional status in maintenance hemodialysis (MHD) patients. Twenty-nine patients on MHD were treated with A(+)D for 4 months (first A(+)D), switched to A(-)D for 4 months, and returned to A(+)D for the next 4-month period (second A(+)D). Metabolic acidosis: Serum bicarbonate (HCO3(-) ) levels did not change in patients with normal HCO3(-) levels (≥20 mEq/L) throughout the study. Meanwhile, in patients with initially low HCO3(-) levels, it was significantly increased during the A(-)D period only. Anemia: In patients with target hemoglobin (Hb) ≥10 g/dL, Hb levels were maintained during the study period, even if the dose of erythropoiesis-stimulating agents (ESAs) decreased. In patients with low Hb levels, it was significantly increased in the A(-)D period without increasing ESA or iron doses. Nutritional Condition: In patients with normal albumin levels (≥3.8 g/dL), albumin did not change throughout the study period. However, in patients with lower albumin levels, it was significantly increased during the A(-)D period. These improvements in metabolic acidosis, anemia, and nutrition in the A(-)D period completely dissipated during the second A(+)D period. Hemodialysis (HD) with A(-)D may improve a patients clinical status with intractable metabolic acidosis, hyporesponsiveness to ESA, and malnutrition that were not normalized in HD with A(+)D.

The removal of serum hepcidin by different dialysis membranes.

Purpose Hepcidin has been suspected to be associated with anemia of chronic disease, which is commonly observed in patients with maintenance hemodialysis (MHD). As almost of hepcidin is bounded to protein, it is essential to clarify which kind of dialysis membrane can remove it efficiently. Methods Ex vivo study: 50 mL of whole blood from healthy volunteers were circulated for 2 h in a microcircuit with mini-dialyzers (acrylonitrile-co-methallyl sulfonate (AN69) or polysulfone (PS)) without ultrafiltration. We measured hepcidin-25 levels at 0, 60, and 120 min in the blood samples. In vivo study: Blood samples were taken from 28 MHD patients at the start and end of HD sessions with PS or AN69. We measured serum levels of hepcidin 20, 22, and 25 by liquid chro-matography tandem mass spectrometry, and also measured serum levels of urea nitrogen (UN), P2microglobulin (MG). Results Ex vivo study: Although serum hepcidin 25 levels increased after the ex vivo session with PS, they significantly decreased with AN69. In vivo study: The reduction ratio of β2MG by PS was significantly higher than that of AN69. On the other hand, there was no significant difference in the reduction ratio of hepcidin 20, 22, and 25 between PS and AN69. Conclusions Both super-flux PS and AN69 similarly removed hepcidin 20 22, and 25. HD with PS might achieve a high removal ratio of hepcidin by enhanced diffusion performance and an increased clearance of small molecule solutes. On the other hand, AN69 might remove hepcidin by adsorption.

Acetate free citrate-containing dialysate increase intact-PTH and BAP levels in the patients with low intact-PTH

BackgroundRecently, acetate-free citrate containing dialysate (A(−)D) was developed. We have already reported about the significant effect of A(−)D on metabolic acidosis, anemia, and malnutrition in maintenance hemodialysis (MHD) patients. In this study, we compared the effect of A(−)D and acetate containing dialysate (A(+)D) on serum calcium and intact-parathyroid hormone (int-PTH) levels.MethodSingle session study: Seventeen patients were treated with A(+)D in one session and also treated with A(−)D in another session. Serum levels of pH, HCO3-, total (t)-calcium, ionized (i)-calcium, and int-PTH were evaluated at the beginning and the end of each session. Cross over study: A total of 29 patients with MHD were treated with A(+)D for 4 months, switched to A(−)D for next 4 months, and returned to A(+)D for the final 4 months.ResultsIn single session study, serum i-calcium and t-calcium levels significantly increased, and int-PTH levels decreased after HD with A(+)D, whereas HD with A(−)D did not affect iCa and int-PTH. In cross over study, if all patients were analyzed, there was no significant difference in serum int-PTH or bone alkaline phosphatase (BAP) levels during each study period. In contrast, in the patients with low int-PTH (<60 pg/mL), serum levels of int-PTH and BAP were significantly increased during the A(−)D, without significant changes in serum t-calcium or i-calcium levels.ConclusionA(−)D containing citrate could affect calcium and PTH levels, and, in 4 month period of crossover study, increased int-PTH levels pararelled with increasing BAP levels, exclusively in MHD patients with low int-PTH levels.

Effect of protoconized therapy for renal anemia on adverse events of patients with maintenance hemodialysis

Purpose We evaluate the effect of the protoconized anemia therapy on adverse events using the Hb and ferritin levels of individual patients undergoing maintenance hemodialysis (MHD). Methods Design: A randomized, parallel group, multi-center study. Patients Two hundred sixty-six MHD patients. Intervention group: The doses of erythropoietin, iron, and vitamin C were adjusted every month based on the ferritin and hemoglobin (Hb) levels according to the protocol. Non-intervention group: The attending physician determined the doses of erythropoietin and iron. Results The maintenance rate of target Hb and ferritin levels were significantly higher in the Intervention group than in the Non-intervention group. The frequency of hospitalization was significantly lower for patients with a higher maintenance rate of target Hb levels than for those with a lower maintenance rate. Conclusions Using an anemia treatment protocol according to the individual Hb and ferritin levels of hemodialysis patients might stabilize the Hb and ferritin levels, which in turn could contribute to the lower frequency of adverse events in MHD patients.