Inhibition of message for FcepsilonRI alpha chain blocks mast cell IL-4 production induced by co-culture with Mycoplasma pneumoniae

Recent Progress in Mycoplasma pneumoniae Infection

Mycoplasma pneumoniae(Mp) is a definite respiratory pathogen affecting people of all ages. This organism is adsorbed on host cell surface through extreme adherent organelles, generating peroxide ions and possible exotoxins. Mp may directly invade host cells and cause latent infections. Induced immunoreactive injury is one of the main factors resulting in clinical symptoms of Mp infection. Polymerase chain reaction (PCR) and serological detection should be combined for diagnosis of Mp infection when nasopharyngeal and oropharyngeal specimens are simultaneously obtained and detected by PCR. The most reliable basis for diagnosis can be obtained with two serological tests in different courses of the disease. Culture methods also bear significance in diagnosing Mp infections andin vitrodrug sensitivity tests.

Mast cells in lung inflammation

Mast cells play an important role in the lung in both health and disease. Their primary role is to initiate an appropriate program of inflammation and repair in response to tissue damage initiated by a variety of diverse stimuli. They are important for host immunity against bacterial infection and potentially in the host immune response to non small cell lung cancer. In situations of ongoing tissue damage, the sustained release of numerous pro-inflammatory mediators, proteases and cytokines, contributes to the pathophysiology of lung diseases such as asthma and interstitial lung disease. A key goal is the development of treatments which attenuate adverse mast cell function when administered chronically to humans in vivo. Such therapies may offer a novel approach to the treatment of many life-threatening diseases.

The change of asthma-associated immunological parameters in children with Mycoplasma pneumoniae infection

BACKGROUND

Mycoplasma pneumoniae (M. pneumoniae), an atypical pathogen, is increasingly recognized as a common and important pathogen. Previous studies showed that M. pneumoniae infection may play a role in asthmatic mechanisms based on evidence collected from peripheral blood or sputum of patients or animal models. However, evidence reported from the airways of patients has been rare.

OBJECTIVE

To estimate the role of M. pneumoniae infection in asthma by measuring the immunological parameters from peripheral blood and bronchoalveolar lavage fluid (BALF) in pediatric patients with mycoplasma pneumonia.

METHODS

A total of 30 patients with mycoplasma pneumonia and 37 patients without M. pneumoniae infection undergoing fiberoptic bronchoscopy were reviewed. The peripheral blood cell count, immunoglobulins (Ig), BALF cell count, and other clinical and laboratory data were reviewed and analyzed.

RESULTS

There were significantly more patients with raised basophil counts in the M. pneumoniae group than that in the control group (p = 0.033). Serum immunoglobulin (Ig) A, IgM, and IgG levels in the M. pneumoniae group were significantly higher than those in the control group (p = 0.008, p = 0.011, and p = 0.019, respectively). The percentage of eosinophils in BALF cells was in the range 0 to 10% in M. pneumoniae patients, while it ranged between 0 and 4% in the control group with a significant difference (p = 0.043). In the M. pneumoniae group, we found that the percentage of eosinophils in the BALF cells was positively correlated with age, the percentage of peripheral eosinophils, and BALF lymphocytes (r = 0.298, p = 0.030; r = 0.341, p = 0.014; r = 0.387, p = 0.006; respectively) and negatively correlated with total peripheral white blood cell (r = -0.387, p = 0.005).

CONCLUSION

These results suggest that M. pneumonia infection is associated with the asthma mechanism, especially in older children.

New insights into the pathogenesis and detection of Mycoplasma pneumoniae infections

Mycoplasma pneumoniae is a common cause of upper and lower respiratory tract infections in persons of all ages and may be responsible for up to 40% of community-acquired pneumonias. A wide array of extrapulmonary events may accompany the infections caused by this organism, related to autoimmunity or direct spread. This review includes a discussion of the latest knowledge concerning the molecular pathological basis of mycoplasmal respiratory disease, how the organism interacts with the host immune system and its association with the development of chronic conditions such as asthma, recent emergence of macrolide resistance and the status of laboratory diagnostic methods.

Epidemiology, clinical manifestations, pathogenesis and laboratory detection of Mycoplasma pneumoniae infections

Since its initial description in the 1940s and eventual elucidation as a highly evolved pathogenic bacterium, Mycoplasma pneumoniae has come to be recognized as a worldwide cause of primary atypical pneumonia. Beyond its ability to cause severe lower respiratory illness and milder upper respiratory symptoms it has become apparent that a wide array of extrapulmonary infectious and postinfectious events may accompany the infections in humans caused by this organism. Autoimmune disorders and chronic diseases such as asthma and arthritis are increasingly being associated with this mycoplasma, which frequently persists in individuals for prolonged periods. The reductive evolutionary process that has led to the minimal genome of M. pneumoniae suggests that it exists as a highly specialized parasitic bacterium capable of residing in an intracellular state within the respiratory tissues, occasionally emerging to produce symptoms. This review includes discussion of some of the newer aspects of our knowledge on this pathogen, characteristics of clinical infections, how it causes disease, the recent emergence of macrolide resistance, and the status of laboratory diagnostic methods.