Immunoglobulin G4-related diseases in the head and neck: a systematic review.

BACKGROUND: Immunoglobulin G4 related disease (IgG4-RD) is a poorly understood chronic inflammatory disorder affecting the middle-aged and elderly that can present to the otolaryngologist. We aim to summarize the current literature regarding the manifestations and management of IgG4-RD in the head and neck. METHODS: Pubmed and EMBASE were searched using the term relevant search algorithm utilizing keywords such as: IgG4 related disease, head and neck, orbit, salivary glands, sialadenitis, Kuttner, angiocentric eosinophilic fibrosis, submandibular, lacrimal, thyroid, dacryoadenitis, nasal, sinus, and Mikulicz's. Reference lists were searched for identification of relevant studies. Case reports, original research and review articles published in English from 1964 to 2014 whose major topic was IgG4-RD affecting the head and neck were included. Data regarding patient demographics, presentation, histopathology, management and treatment outcomes of IgG4-RD were extracted. Level of evidence was also assessed and data were pooled where possible. Three independent reviewers screened eligible studies; extracted relevant data and discrepancies were resolved by consensus, where applicable. Descriptive and comparative statistics were performed. RESULTS: Fourty-three articles met our inclusion criteria. IgG4-RD most often presents as a mass lesion in the head and neck region. Common diagnostic features include: (1) elevated serum IgG4 level, (2) marked infiltration of exocrine glands by IgG4-positive plasma cells with fibrosis, and (3) marked improvement with corticosteroid therapy and additional immunosuppressive therapy in corticosteroid refractory cases. Early diagnosis and involvement of rheumatology is important in management. CONCLUSIONS: IgG4-RD is a challenging non-surgical disease that has multiple manifestations in the head and neck. It must be distinguished from various mimics including malignancy, systemic diseases, and infectious. Otolaryngology-Head and Neck surgeons should be aware of this condition and its management.

Radical kinetics in sub- and supercritical carbon dioxide: thermodynamic rate tuning.

We report rate constants for muonium addition to 1,1-difluoroethylene (vinylidene fluoride) in CO2 at 290-530 K, 40-360 bar, and 0.05-0.90 g cm(-3). Rate constants are mapped against their thermodynamic conditions, demonstrating the kinetic tuning ability of the solvent. The reaction exhibits critical slowing near conditions of maximum solvent isothermal compressibility, where activation volumes of unprecedentedly large magnitudes on the order of ±10(6) cm(3) mol(-1) are observed. Such values are suggestive of pressure being a significant parameter for tuning fluorolkene reactivity.