An updated review of quality-of-life questionnaires for urinary incontinence and overactive bladder: Which ones to use and why

Overactive bladder and stress urinary incontinence have a profound impact on patients’ health-related quality of life (HRQL). The purpose this paper is to update a previously published review of condition-specific HRQL measures validated among patients with symptoms of urinary incontinence or overactive bladder. For this update, MEDLINE (accessed via PubMed) and EMBASE literature searches were performed to identify articles or abstracts published since 2004 that focus on the development, psychometric validation, and use of relevant instruments. Target populations and psychometric properties (reliability, validity, responsiveness to change) of 22 questionnaires are summarized. A range of well-validated, condition-specific HRQL measures are available. Recommendations are provided regarding which measures to use in different situations. When choosing among instruments, psychometric evidence and the match of an instrument to the study population should be considered.     

Fc-Fc interactions of human IgG4 require dissociation of heavy chains and are formed predominantly by the intra-chain hinge isomer

Human IgG4 antibodies are remarkable not only because they can dynamically exchange half-molecules (Fab-arm exchange) but also for their ability to interact with the Fc part of IgG4 and other IgG subclasses. This rheumatoid factor-like binding of IgG4 does not appear to take place spontaneously, because it is only observed to solid-phase or antigen-bound IgG. We hypothesized that Fc-Fc interactions might involve (partial) dissociation of heavy chains. We investigated the molecular basis of these Fc-Fc interactions, and found that the structural features important for the exchange reaction also control the Fc binding activity. In particular, if arginine-409 in the CH(3)-CH(3) interface in IgG4 is mutated to lysine (the equivalent in IgG1), Fc-Fc interactions are formed 3 orders of magnitude less efficiently compared to the wild-type. This mutation was previously found to increase the CH(3)-CH(3) interaction strength in IgG4. Furthermore, of the two hinge isomers of IgG4, the intra-chain (non-covalently linked) form was found to form Fc-Fc interactions, but not the inter-chain form. Together, these results demonstrate that Fc-Fc interactions of IgG4 involve (partial or complete) dissociation of heavy chains. The promiscuity to other IgG subclasses suggests that IgG4 might act as scavenger to IgG molecules with impaired structural integrity.