Oral Iron Absorption of Ferric Citrate Hydrate and Hepcidin-25 in Hemodialysis Patients: A Prospective, Multicenter, Observational Riona-Oral Iron Absorption Trial.

Oral ferric citrate hydrate (FCH) is effective for iron deficiencies in hemodialysis patients; however, how iron balance in the body affects iron absorption in the intestinal tract remains unclear. This prospective observational study (Riona-Oral Iron Absorption Trial, R-OIAT, UMIN 000031406) was conducted at 42 hemodialysis centers in Japan, wherein 268 hemodialysis patients without inflammation were enrolled and treated with a fixed amount of FCH for 6 months. We assessed the predictive value of hepcidin-25 for iron absorption and iron shift between ferritin (FTN) and red blood cells (RBCs) following FCH therapy. Serum iron changes at 2 h (ΔFe2h) after FCH ingestion were evaluated as iron absorption. The primary outcome was the quantitative delineation of iron variables with respect to ΔFe2h, and the secondary outcome was the description of the predictors of the body's iron balance. Generalized estimating equations (GEEs) were used to identify the determinants of iron absorption during each phase of FCH treatment. ΔFe2h increased when hepcidin-25 and TSAT decreased (-0.459, -0.643 to -0.276, p = 0.000; -0.648, -1.099 to -0.197, p = 0.005, respectively) in GEEs. FTN increased when RBCs decreased (-1.392, -1.749 to -1.035, p = 0.000) and hepcidin-25 increased (0.297, 0.239 to 0.355, p = 0.000). Limiting erythropoiesis to maintain hemoglobin levels induces RBC reduction in hemodialysis patients, resulting in increased hepcidin-25 and FTN levels. Hepcidin-25 production may prompt an iron shift from RBC iron to FTN iron, inhibiting iron absorption even with continued FCH intake.

Inflammatory abdominal aortic aneurysm: close relationship to IgG4-related periaortitis.

Inflammatory abdominal aortic aneurysm (AAA) is a member of a family of disorders referred to as "chronic periaortitis" together with retroperitoneal fibrosis. Retroperitoneal fibrosis is included in IgG4-related disease, which is characterized by numerous infiltrating IgG4-positive plasma cells and high serum IgG4 concentrations. However, the relationship between IgG4-related disease and inflammatory AAA has not been documented. In this study, we examined the clinicopathologic characteristics of inflammatory (10 cases) and atherosclerotic (22 cases) AAAs, based on the hypothesis that inflammatory AAA might be related to IgG4-related disease. Cases of inflammatory AAA could be classified into 2 groups based on immunostaining of IgG4. Four patients showed diffuse infiltration of abundant IgG4-positive plasma cells (IgG4-related cases), whereas the remaining 6 cases of inflammatory AAA and all cases of atherosclerotic AAA had only a few IgG4-positive plasma cells (non-IgG4-related cases). IgG4-related inflammatory AAA was pathologically characterized by the frequent infiltration of eosinophils, lymph follicle formation, perineural inflammatory extension, and inconspicuous infiltration of neutrophils compared with non-IgG4-related inflammatory AAA. Obliterative phlebitis, which is venous occlusion with inflammatory cell infiltration, is observed in all IgG4-related cases. In addition, serum IgG4 concentrations were significantly higher in IgG4-related inflammatory AAA (109 to 559 mg/dL, normal range: 4 to 110 mg/dL) than non-IgG4-related inflammatory AAA (32 to 59 mg/dL) and all atherosclerotic AAA (12 to 83 mg/dL). In conclusion, inflammatory AAAs might be classified into 2 groups: IgG4-related or nonrelated. The former might be one of the IgG4-related diseases, and could be included in IgG4-related periaortitis together with retroperitoneal fibrosis.

[Control of accuracy of immunoserological laboratory data on medical network and standardization].

Construction of a medical network for each region and organization has become possible by utilization of information technology. Standardization of the data on the medical network is urgent. Especially, the standardization of immunoserological data is much delayed. In this study, the possibility of standardization of such data was reconsidered based on the findings from various control surveys. Regarding the measurement items for serum concentrations of proteins and other compounds, we concluded that standardization should occur in a manner similar to the method for standardization of biochemical data and accurate control. The data on CRP, IgG, IgA, IgM and AFP, which are determined using the respective standard compound, were converged to a range with inter-facility differences of less than 10% CV. The data on CEA were also converged to achieve an inter-facility difference of less than 10% CV through repeated survey. Automatic measurement for the markers of infection diseases has progressed, and the expression of measurements was changed to the absolute value of COI, U/ml or IU/ml although it was titer in the past. Since these expressions now coexist, it is impossible to standardize the data with absolute qualitative values. It seemed necessary to present them uniformly with qualitative or clinical criteria values or express the presence or absence of infection by a combination of related markers. The measurements obtained from autoantibody-related tests using identical reagent were found coincident, but measurements obtained using different reagents were discrepant and the differences were greater than the sensitivity of measurement. In immunoserological testing and immunochemical testing, it is most important whether the antigen/antibody used as the reagent is the same preparation or not. Therefore, the test should be reconsidered through setting a certain restrictions on each recognition site of epitope and antibody. Thus, we concluded that use of a suitable standard substance is effective for standardization of immunological data.