Vasculitis and rapidly progressive glomerulonephritis in the elderly.

The proportion of patients with vasculitis and rapidly progressive nephritis aged 70 years or over has risen from about 10% in the 1980s to over 30% in series reported in the 1990s. This study was undertaken to examine the presentation and outcome of such older patients. Seventeen of 56 patients (30%) who presented at two renal units were aged 70 years or over. Mean creatinine level at presentation was 530 mumol/l, and five patients received dialysis at presentation. Outcome was dependent on three factors, namely comorbid pathology, response to immunosuppressive therapy, and the occurrence in three cases of temporary spontaneous partial remission. Overall patient survival at one and two years was 62.5% and 50%, respectively, and 90% and 100% of surviving patients were independent of dialysis at one and two years, respectively. Response to chemotherapy was excellent, with full rehabilitation in many cases and no deaths directly attributable to adverse effects of immunosuppressive therapy. We conclude that diagnosis of vasculitis and rapidly progressive glomerulonephritis by renal biopsy and the subsequent administration of chemotherapy (including cyclophosphamide in many cases) resulted in a worthwhile benefit in these elderly patients

Probing for Membrane Domains in the Endoplasmic Reticulum: Retention and Degradation of Unassembled MHC Class I Molecules

Quality control of protein biosynthesis requires ER-retention and ER-associated degradation (ERAD) of unassembled/misfolded molecules. Although some evidence exists for the organization of the ER into functionally distinct membrane domains, it is unknown if such domains are involved in the retention and ERAD of unassembled proteins. Here, it is shown that unassembled MHC class I molecules are retained in the ER without accumulating at ER-exit sites or in the ERGIC of β2m(−/−) cells. Furthermore, these molecules did not cluster in the ER membrane and appeared to be highly mobile even when ERAD or their association with calnexin were inhibited. However, upon ATP depletion, they were reversibly segregated into an ER membrane domain, distinct from ER exit sites, which included calnexin and COPII, but not the ERGIC marker protein p58. This quality control domain was also observed upon prolonged inhibition of proteasomes. Microtubules were required for its appearance. Segregation of unfolded proteins, ER-resident chaperones, and COPII may be a temporal adaptation to cell stress