Clearance of recruited immune cells is necessary to resolve inflammatory reactions. We show here that matrix metalloproteinase 2 (MMP2), as part of an interleukin 13 (IL-13)-dependent regulatory loop, dampens inflammation by promoting the egress of inflammatory cells into the airway lumen. MMP2 −/− mice showed a robust asthma phenotype and increased susceptibility to asphyxiation induced by allergens. However, whereas the lack of MMP2 reduced the influx of cells into bronchoalveolar lavage (BAL), numerous inflammatory cells accumulated in the lung parenchyma. BAL of MMP2 −/− mice lacked normal chemotactic activity, whereas lung inflammatory cells from the same mice showed appropriate chemotactic responses. Thus, MMP2 establishes the chemotactic gradient required for egression of lung inflammatory cells and prevention of lethal asphyxiation.

Muir-Torre syndrome should be considered in patients who develop sebaceous tumors of the ocular adnexa. Immunohistochemistry for MSH2 is a practical initial approach for screening MTS in patients with sebaceous tumors.

Current data overwhelmingly document the existence of a worldwide asthma epidemic, although individual studies remain controversial. The epidemic is thought to involve primarily persons with allergic asthma, and many diverse theories, based on an immunopathologic understanding of disease, have recently emerged to explain this involvement. In the context of recent insights into the immune basis of experimental asthma, we discuss in this review the leading asthma epidemic theories, including a new theory based on inhaled environmental proteases. Although no single theory may yet be fully embraced, there exists substantial hope that a unifying mechanism for the epidemic will be revealed through additional research. Key words: adjuvant, air pollution, aspirin, asthma, costimulatory molecule, dust mite, helminth, immunoglobulin E, protease, T H 2 cell.

Phoma species, though rarely pathogenic to humans, may cause keratitis in some patients. To our knowledge, this is the first well-documented case of Phoma keratitis.