[Influence of hemodialysis on total and free malondialdehyde measured by a new HPLC method]. / Influence de l'hémodialyse sur les concentrations de malonedialdéhyde total et libre, mesurées par une nouvelle technique HPLC spécifique.

Accurate evaluation of oxidative stress is needed for patients on chronic hemodialysis (HD), as cardiovascular risk level seems related to it. Oxidative stress is often evaluated by measuring an end product of lipoperoxidation named malondialdehyde (MDA). However, the most common technique for measuring MDA, the Thio Barbituric Acid Reactive Substances method (TBARS), is known to be sensitive but poorly specific. We measured true total and free plasma MDA in fifty-four unselected patients on long-term HD, before and after HD sessions, by a new, highly specific HPLC method. Total and free MDA were higher before than after dialysis. Essentially, free MDA was decreased by HD but its fractional decrease was lower than that of urea or creatinine. This confirms that, in fact, free MDA is more or less bound to low molecular weight compounds and/or suggests that MDA may be produced mainly during HD sessions. We propose this new tool to further explore the relationship between oxidative stress, HD and true MDA.

Comparison of a Bayesian network with a logistic regression model to forecast IgA nephropathy.

Models are increasingly used in clinical practice to improve the accuracy of diagnosis. The aim of our work was to compare a Bayesian network to logistic regression to forecast IgA nephropathy (IgAN) from simple clinical and biological criteria. Retrospectively, we pooled the results of all biopsies (n = 155) performed by nephrologists in a specialist clinical facility between 2002 and 2009. Two groups were constituted at random. The first subgroup was used to determine the parameters of the models adjusted to data by logistic regression or Bayesian network, and the second was used to compare the performances of the models using receiver operating characteristics (ROC) curves. IgAN was found (on pathology) in 44 patients. Areas under the ROC curves provided by both methods were highly significant but not different from each other. Based on the highest Youden indices, sensitivity reached (100% versus 67%) and specificity (73% versus 95%) using the Bayesian network and logistic regression, respectively. A Bayesian network is at least as efficient as logistic regression to estimate the probability of a patient suffering IgAN, using simple clinical and biological data obtained during consultation.

Safety and efficacy of rituximab treatment for vasculitis in hepatitis B virus-associated type II cryoglobulinemia: a case report.

INTRODUCTION: Systemic B-cell depletion and clinical remission of the systemic effects of cryoglobulins have already been achieved using rituximab in hepatitis C virus-positive immunocompetent patients. Conversely, to the best of our knowledge there are no reports in the literature regarding the use of rituximab in hepatitis B virus-associated cryoglobulinemia. CASE PRESENTATION: We report here the case of a 60-year-old Caucasian man who presented with hepatitis B virus-associated type II cryoglobulinemia with severe multisystem disease, including membranoproliferative glomerulonephritis with acute renal failure. The vasculitis was refractory to conventional and antiviral therapy but rituximab use led to a fall in cryoglobulin levels and disease control. The B-cell depletion was safe and efficient to induce a complete remission of the disease. CONCLUSION: Our case highlights the benefit and the efficacy of rituximab in association with antiviral therapy in small vessel vasculitis related to hepatitis B virus-associated mixed cryoglobulinemia.

Syndrome of pleural and retrosternal "bridging" fibrosis and retroperitoneal fibrosis in patients with asbestos exposure.

Two case histories are described of pleural and anterior mediastinal fibrosis presenting as a continuous fibrotic process with thick parietal pleural plaques extending from one pleura to the contralateral pleura through the retrosternal area, and with retroperitoneal fibrosis. Follow-up over 4 years in one case demonstrated rapid progression of disease, with pleural fibrosis preceding retrosternal and retroperitoneal fibrosis. Histopathological analysis in both cases showed non-tumoral fibrosis with broad fibrous bundles surrounding fibroblasts (and lymphocytes in one case). Possible causes such as infections and exposure to ergot derivatives were excluded. Both patients had been slightly or moderately exposed to asbestos.