Interaction of the mechanisms of beta 2-microglobulin convection, diffusion, and adsorption in line hemodiafiltration

The in vivo contribution of diffusion, convection ad adsorption to beta 2-microglobulin (beta 2-m) elimination by hemodiafiltration (HDF) was investigated. 11 patients (8M/3W), with a mean age of 59 +/- 10 years and weighing 62.7 +/- 8.7 kg were studied. A 1.89 m2 polysulphone membrane was used in 180 min postdilution HDF. Samples at blood inlet (bi), blood autlet (bo), dialysate outlet (do) and ultrafiltrate (uf) were taken to determine beta 2-m concentrations at 30 and 150 min. Rates of flow (Q, ml(min) prescribed were: infusion, Qinf = 103.6 +/- 12.3, Quf = 14.6 +/- 4.0 y Qb = 465 +/- 5.0. Effective Qbi was automatically measured by the machine and Qdo = 800 + Quf. The removed beta 2-m mass (M, mg/min) was obtained by multiplying rates of flow (Q, L/min) by beta 2-m concentrations (mg/L) at each sampling point. From mass balance, we calculated the mass of beta 2-m removed (mg/min) by adsorption 0.23 +/- 0.2, by convection 0.7 +/- 0.3 and by diffusion 1.0 +/- 0.4, at 30 min. At 150 min, the beta 2-m mass removed was -0.06 +/- 0.1 by adsorption 0.4 +/- 0.1 by convection and 0.3 +/- 0.1 by diffusion. In HDF, these beta 2-m eliminating mechanisms play a variable role throughout the session. The more significant conclusion is that diffusion of beta 2-m with a synthetic "open" membrane is an important method of removing beta 2-m, comparable to convection over the whole procedure. That result explain the relative efficacy of beta 2-m clearance by HDF convection, and also explain why isolated diffusion is an efficient mechanism for beta 2-m removal by high-flux hemodialysis.     

Risk factors associated with incident clinical vertebral and nonvertebral fractures in Japanese women with rheumatoid arthritis: a prospective 54-month observational study

OBJECTIVE: To evaluate the association between potential risk factors and incident clinical fractures in Japanese patients with rheumatoid arthritis (RA). METHODS: A total of 1733 female patients with RA over age 50 years were enrolled in a prospective observational cohort study. Participants were followed for 54 months from October 2000 to March 2005, and classified into 4 groups according to incident fracture status since baseline: those without a new fracture; those with a new clinically recognized vertebral fracture; those with an incident nonvertebral fracture at the wrist, hip, humerus, pelvis, or ribs (main nonvertebral fracture); and those with any new nonvertebral fracture. Cox proportional hazard models were used to analyze independent contributions of various risk factors to fracture incidence. RESULTS: During the followup period, 33, 34, and 98 patients developed a vertebral, a main nonvertebral, and any nonvertebral fracture, respectively. The Japanese Health Assessment Questionnaire (J-HAQ) score was associated with relative risks (RR) of 2.42 (95% confidence interval 1.42-4.14), 1.76 (95% CI 1.07-2.89), and 1.73 (95% CI 1.29-2.32) for vertebral, main nonvertebral, and all nonvertebral fractures. The risks of vertebral and any nonvertebral fractures were increased for age over 70 years compared with age in the 50s (RR 3.25, 95% CI 1.19-8.86; and RR 2.22, 95% CI 1.20-4.10, respectively). Clinical variables and medications were associated with a new fracture. CONCLUSION: HAQ, age, history of any prior fracture, and orthopedic surgery for RA appear to be associated with fractures in Japanese women with RA.     

Influence of Type of Dietary Fat (Olive and Sunflower Oil) upon Gastric Acid Secretion and Release of Gastrin, Somatostatin, and Peptide YY in Man

The effects of adaptation to two diets differingin the type of dietary fat on the gastric acid secretoryresponse to food and on the circulating levels ofgastrin, somatostatin and peptide YY (PYY) were examined in humans. The study involved 18cholecystectomized subjects previously submitted to a30-day adaptation period to diets containing olive(group O) or sunflower oil (group S) as the fat source. During the experiments, physiologicalstimulation was achieved by ingestion of 200 ml of oleicacid- (group O) or linoleic acid-enriched (group S)liquid mixed meals. These resulted in an immediate rise in gastric pH. In group S, the return to thepremeal value was completed within 60 min, and a furtherdecline to values significantly lower than the basalones was observed at the end of the study period. In contrast, ingestion of the meal containingolive oil attenuated and prolonged the pH decrease afterthe meal, this being associated with the suppression ofpostprandial gastrin response. Food ingestion induced no significant changes in plasmasomatostatin concentration in either group, and nosignificant differences were revealed between themduring the basal or postprandial situations. Plasma PYYlevels were consistently higher in group O throughoutthe entire study period, although significance wasreached only at resting. In conclusion, our results showthat a 30-day adaptation period to diets containing olive oil as the main source of dietary fatresults, compared with those containing sunflower oil,in an attenuated gastric secretory function in responseto a liquid meal in humans. The effects of olive oil were associated with a suppression of serumgastrin and higher levels of PYY.     

Riesgo de fenómenos tromboembólicos en pacientes con enfermedad inflamatoria intestinal

Introduction

Inflammatory bowel disease (IBD) is an independent risk factor for thromboembolic phenomena (TEP). We evaluated the prevalence and the possible risk factors associated with developing TEP in patients with IBD in our center.

Material and methods

Data were retrospectively collected from January 1995 to December 2011 from 23 patients. A total of 61% were diagnosed with Crohn's disease (CD) and 39% with ulcerative colitis (UC) according to routine criteria.

Results

When the Montreal classification was used, 58% of the patients with CD had an inflammatory pattern (B1), 25% a stenosing pattern (B2) and 17% a fistulizing pattern (B3). Half the patients had ileocolic involvement (L3), one-third had colonic involvement (L2) and the remainder had ileal involvement (L1). Among patients with UC according to the Montreal classification, 78% had extensive colitis (E3), 11% had left colonic involvement (E2) and 11% had proctocolitis (E1). During the event, almost half the patients with UC had severe inflammatory activity (S3; 44%), 33% had mild-moderate activity (S1: 22%, S2: 11%) and only 22% were in remission (S0). Overall, at the time of the TEP, 48% of the patients had mild-moderate activity and 22% had severe activity. Likewise, 44% were hospitalized at the time of the event. In UC, an increase in the prevalence of TEP was found in admitted patients (66%). None of the patients had a family history of TEP, two patients (9%) had associated thrombophilia and 26% were active smokers. There were no TEP during pregnancy. Only one patient was taking contraceptive pills when the event occurred. The most frequent forms of TEP were deep vein thrombosis of the legs (55%) followed by pulmonary thromboembolism (25%).

Conclusions

TEP are relatively frequent in patients with IBD, with a strong impact on morbidity and mortality. In our series, risk factors for these events were more extensive involvement (any of the groups) and severe inflammatory activity. No significant association between classical risk factors such as the use of contraceptives, pregnancy, coagulation disorders or smoking and the risk of TEP were found.     

Analysis of clinical AIDS-free interval after CD4+ cell counts fall below 200 × 106 L−1 in Japanese Haemophiliacs infected with HIV-1

We analysed the time from the date CD4+ cell counts fell below 200 × 10⁶ L⁻¹, defined as t _i, to the onset of clinical AIDS, according to the 1987 Centers for Disease Control and Prevention case definition, in 129 Japanese Haemophilia patients infected with HIV-1. The cumulative onset of clinical AIDS was analysed by the Kaplan–Meier method and proportional hazard model. Incorporated covariates were age of each patient at time t _i, as well as CD4+ and CD8+ cell counts, serum levels of IgG, IgA, IgM, GOT and GPT at t _i. The time of antiretroviral treatment initiation was also considered. The 50% AIDS-free interval after t _i was 3.00 years (95% confidence interval (CI), range 0.49–5.51) and 1.71 years (95% CI, range 0.66–2.76) for the patients at CDC stage II and stage III, respectively (significantly different, P = 0.0013). Among the patients at CDC stage II at t _i, higher levels of IgA were tightly associated with a shorter period from t _i to onset of clinical AIDS ( P < 0.0001), and relative hazard was 1.35 (95% CI, 1.11–1.64) with increase of IgA level by 1.0 g L⁻¹. Thus there is a broad distribution in the time to onset of clinical AIDS in Japanese Haemophiliacs even after CD4+ cell counts fall below 200 × 10⁶ L⁻¹. This should be taken into consideration in deciding upon the therapy and care of HIV-1 infected people.     

Utilidad y coste de la cápsula endoscópica. Tres años de experiencia de nuestro centro

Introduction

The aim of this study was to evaluate the safety, clinical impact and costs associated with capsule endoscopy (CE) in our center.

Results

We retrospectively analyzed the CE procedures carried out in our center from 2009 to 2012. The most frequent indications were investigation of anemia (39%), obscure gastrointestinal bleeding (OGIB) (19%) and inflammatory bowel disease (IBD)(18%). Findings were positive in 51% of the patients, which had a clinical impact in 36.5%. The indication in which CE had the greatest clinical impact was IBD (74.5%, p<0,001). The clinical impact of CE in OGIB and anemia was 41% and 26%, respectively. The procedures performed represented an investment of at least 132 600€; since 63.5% of the procedures had no clinical impact, an investment of 84 200€ had no effect on patient management. In patients who underwent CE for OGIB, early performance of the procedure (<7 days) was related to the presence of pathological findings and clinical impact. We found no other epidemiological, clinical or analytic factors able to predict the clinical impact of CE in the various indications.

Conclusions

In our experience, CE had the greatest impact in the study of IBD and, if performed early, in OGIB. However, the indications for CE in the study of anemia should be most precisely defined to achieve a greater clinical impact in this disorder.     

Incidence and natural history of pure red cell aplasia in major ABO‐mismatched haematopoietic cell transplantation

Major ABO mismatching is not considered a contraindication to allogeneic haematopoietic stem cell transplantation (HSCT). Modern reduced‐intensity conditioning and reduced‐toxicity regimens cause much less myeloablation than conventional myeloablative regimens, such as cyclophosphamide with busulfan or total body irradiation, which may affect the incidence of pure red cell aplasia (PRCA). We estimated the incidence and described the natural history of PRCA in patients with major ABO‐mismatched donor stem cells. Between 2007 and 2008, 161 (27% of all patients undergoing HSCT) underwent allogeneic HSCT with major ABO‐mismatched stem cells and 12 (7·5%) of these patients developed PRCA. Thirty and ninety day T‐cell and myeloid cell chimerism and neutrophil and platelet engraftment did not differ between patients who developed PRCA and those who did not. The only risk factor associated with PRCA was the use of a fludarabine/busulfan conditioning regimen. All patients with PRCA needed red cell transfusion for several months after HSCT resulting in significant iron overload. Pure red cell aplasia resolved spontaneously in the majority (seven patients) but only resolved after stopping tacrolimus in three patients. Hence, after major ABO‐mismatched HSCT, the incidence of PRCA was 7·5% and it resolved spontaneously or after withdrawal of immunosuppression in the majority of patients.