The Role of the Plasminogen/Plasmin System in Inflammation of the Oral Cavity.

The oral cavity is a unique environment that consists of teeth surrounded by periodontal tissues, oral mucosae with minor salivary glands, and terminal parts of major salivary glands that open into the oral cavity. The cavity is constantly exposed to viral and microbial pathogens. Recent studies indicate that components of the plasminogen (Plg)/plasmin (Pm) system are expressed in tissues of the oral cavity, such as the salivary gland, and contribute to microbial infection and inflammation, such as periodontitis. The Plg/Pm system fulfills two major functions: (a) the destruction of fibrin deposits in the bloodstream or damaged tissues, a process called fibrinolysis, and (b) non-fibrinolytic actions that include the proteolytic modulation of proteins. One can observe both functions during inflammation. The virus that causes the coronavirus disease 2019 (COVID-19) exploits the fibrinolytic and non-fibrinolytic functions of the Plg/Pm system in the oral cavity. During COVID-19, well-established coagulopathy with the development of microthrombi requires constant activation of the fibrinolytic function. Furthermore, viral entry is modulated by receptors such as TMPRSS2, which is necessary in the oral cavity, leading to a derailed immune response that peaks in cytokine storm syndrome. This paper outlines the significance of the Plg/Pm system for infectious and inflammatory diseases that start in the oral cavity.

Difficulties in diagnosing of measles inclusion body encephalitis in a child with acute lymphoblastic leukemia.

The measles epidemic was observed in Ukraine during 20172019. According to WHO, in Ukraine there was registered the highest number of measles cases in Europe during that period [8]. Measles is characterized by an acute course with fever, maculopapular rash, cough, conjunctivitis and can lead to central nervous system complications (encephalitis, encephalomyelitis) and bronchopulmonary system complications (laryngotracheobronchitis, bronchiolitis, pneumonia). In immunocompetent patients, viremia ends after the end of clinical signs, in contrast to immunosuppressed individuals, who could develop viremia from one month up to a year. We have described a case of measles inclusion body encephalitis (MIBE) or subacute measles encephalitis (SME) in an unvaccinated child with an acute lymphoblastic leukemia (ALL). The diagnosis was confirmed by the synthesis of IgG antibodies to the measles virus in the cerebrospinal fluid and by the MRI results. The disease had a dramatic course and ended in death.