Severe mycoplasma pneumonia

Novel aspects on the pathogenesis of Mycoplasma pneumoniae pneumonia and therapeutic implications

Mycoplasma pneumoniae (Mp) is a leading cause of community acquired pneumonia. Knowledge regarding Mp pneumonia obtained from animal models or human subjects has been discussed in many different reports. Accumulated expertise concerning this critical issue has been hard to apply clinically, and potential problems may remain undiscovered. Therefore, our multidisciplinary team extensively reviewed the literature regarding Mp pneumonia, and compared findings from animal models with those from human subjects. In human beings, the characteristic pathological features of Mp pneumonia have been reported as alveolar infiltration with neutrophils and lymphocytes and lymphocyte/plasma cell infiltrates in the peri-bronchovascular area. Herein, we demonstrated the novel aspects of Mp pneumonia that the severity of the Mp pneumonia seemed to depend on the host innate immunity to the Mp, which might be accelerated by antecedent Mp exposure (re-exposure or latent respiratory infection) through up-regulation of Toll-like receptor 2 expression on bronchial epithelial cells and alveolar macrophages. The macrolides therapy might be beneficial for the patients with macrolide-resistant Mp pneumonia via not bacteriological but immunomodulative effects. This exhaustive review focuses on pathogenesis and extends to some therapeutic implications such as clarithromycin, and discusses the various diverse aspects of Mp pneumonia. It is our hope that this might lead to new insights into this common respiratory disease.

Pediatric respiratory infections by Mycoplasma pneumoniae

Mycoplasma pneumoniae is one of the most common agents of community-acquired pneumonia in children and young adults. Although M. pneumoniae is a small bacterium that can reproduce in an artificial culture medium and is known to be sensitive to certain antibiotics in vitro as well as in vivo, the immunopathogenesis of M. pneumoniae in the human host is not fully understood. The epidemiologic characteristics, including periodic epidemics, and some clinical characteristics of M. pneumoniae are similar to those observed in systemic viral infections. Many experimental and clinical studies have suggested that the pathogenesis of lung injuries in M. pneumoniae infection is associated with a cell-mediated immune reaction, including high responsiveness to corticosteroid therapy. This paper presents an overview of M. pneumoniae infections, with emphasis on epidemiology, pathogenesis and treatment.

Fulminant Mycoplasma pneumoniae pneumonia

The frequency of fulminant pneumonia due to Mycoplasma pneumoniae is relatively rare despite the high prevalence of Mycoplasma species infection in the general population. We recently encountered such a case and have reviewed the English-language literature on cases of M pneumoniae pneumonia that have resulted in respiratory failure or death. Due to host factors or on epidemiologic grounds, fulminant cases seem to be more common in young healthy adults, in males, and possibly in smokers among the 46 patients we found. An enhanced host cellular immune response may be responsible for the development of severe cases. A spectrum of small airways disease is characteristic, including cellular bronchiolitis and bronchiolitis obliterans with and without organizing pneumonia. Based largely on anecdotal experience, corticosteroid use may be salutary in patients with respiratory failure. For reasons that are not well known, the incidence of pulmonary thromboembolism is increased in fatal cases.

Chronic interstitial pulmonary fibrosis following Mycoplasma pneumoniae pneumonia

An unusual case of chronic interstitial fibrosis that developed as a sequela of Mycoplasma pneumoniae pneumonia is described. Predominant manifestations included progressive exertional dyspnea, shortness of breath, persisting lung infiltrates, low lung volumes, and low pulmonary diffusing capacity. Open lung biopsy one year after the acute stage of mycoplasma pneumonia revealed focal interstitial fibrosis with early pleural thickening, hypertrophic alveolar lining cells, and peribronchiolar lymphoid cell infiltrates. Improvement in clinical manifestations, radiologic findings, and pulmonary function results occurred with steroid therapy.

Importance of viruses and Legionella pneumophila in respiratory exacerbations of young adults with cystic fibrosis

From January to April 1980 46 young adults with cystic fibrosis were studied for evidence of infection with a wide variety of microorganisms, including viruses and Legionella pneumophila. Two groups of patients were investigated: a "deteriorated" group of 24 patients who had experienced an increase in lower respiratory tract symptoms and fall in lung function values in the course of one month before the start of the study and a "stable" group of 22 patients with no such deterioration. All serological tests were repeated at one month and then one year after the beginning of the study. A fourfold rise in titres of antibodies to various viruses, Mycoplasma pneumoniae, and Coxiella burnetii was obtained in seven (29%) of the deteriorated group but in only one (4.5%) of the stable group (p less than 0.05). One other patient showed a fourfold rise in L pneumophila antibody titre (on the basis of the indirect fluorescent antibody test), which was accompanied by a respiratory illness consistent with legionnaires' disease. Eight of the 46 patients (17.4%) had demonstrable titres of antibody against L pneumophila (1/32 or above).

Mycoplasmal pneumonia and adult respiratory distress syndrome: a complication to be recognized

Mycoplasma pneumoniae pneumonia is usually a mild, self-limited disease. Complications are rare. A patient is presented with adult respiratory distress syndrome. Recognition of this unusual complication, presenting as a common disease syndrome, is emphasized.

Life-threatening Mycoplasma pneumoniae infection

Pneumonia due to Mycoplasma pneumoniae is common, but it is rarely life-threatening. A case is reported in a previously healthy adult whose illness was severe enough to require treatment with intermittent positive pressure ventilation (IPPV) for 14 days and which resolved after treatment with corticosteroids.

Mycoplasma pneumonia with fulminant evolution into diffuse interstitial fibrosis

A fatal case of interstitial pneumonia caused by Mycoplasma pneumoniae with fulminant evolution into diffuse interstitial fibrosis is reported. Treatment with tetracycline and corticosteroids failed to arrest the progress of the disease. Fatal Mycoplasma pneumoniae infections have been reported previously and some degree of pulmonary fibrosis has been described in a few cases but as far as could be ascertained there are no other well-documented cases of diffuse interstitial fibrosis with proved Mycoplasma pneumoniae infection.