Etiology of parapneumonic effusion and pleural empyema in children. The role of conventional and molecular microbiological tests.

BACKGROUND: An increasing incidence of parapneumonic effusion and pleural empyema (PPE/PE) has been reported in recent studies. As only few data on etiology of PPE/PE in Central Europe have been reported, we undertook a study on the etiology of PPE/PE in children, using both standard culture and molecular techniques. METHODS: This prospective study was conducted between June 2011 and December 2013. Consecutive children with PPE/PE complicating community acquired pneumonia, who required diagnostic/therapeutic thoracentesis were included. Blood and pleural fluid samples for microbiological cultures were collected. Molecular methods were applied to identify Streptococcus pneumonia, Haemophilus influenzae, Staphylococcus aureus, Streptococcus pyogenes, Mycoplasma pneumoniae, Chlamydophila pneumoniae, and respiratory viruses in pleural fluid. RESULTS: The study group included 64 children, median age 4 (1-15). Seven of 64 (10.9%) blood cultures and 11 of 64 (17.2%) pleural fluid cultures revealed bacterial growth. The most common bacteria detected was S. pneumoniae (13 blood and pleural fluid samples from 11/64 (17.2%) children). DNA sequences of typical bacteria were found in 29/64 (45.3%) pleural fluid samples. S. pneumoniae was identified in 90% of these samples. The most common serotypes were: serotype 6B in 9/26 (36.6%), 19A in 6/26 (23%), serotype 3 in 3/26 (11.5%), 6A and 23F (both in 2/26 i.e. 7.7%) patients. Molecular methods identified atypical bacteria in 8/58 (13.8%) and respiratory viruses in 12/58 (20.7%) pleural fluid samples. CONCLUSIONS: S. pneumoniae, in particular serotype 6B and 19A, is the most common etiologic agent of PPE/PE in Polish children. The use of PCR significantly improves pathogen identification in pleural fluid.

Survey of pleuritis and pulmonary lesions in pigs at abattoir with a focus on the extent of the condition and herd risk factors.

Cranioventral pulmonary consolidation (enzootic pneumonia-like lesions) and chronic pleuritis (CP) are common findings in slaughtered pigs. Pleural lesions involving dorsocaudal lobes are suggestive of pleuropneumonia due to Actinobacillus pleuropneumoniae. In this report the results of an abattoir survey of pleuritis and pulmonary lesions in pigs is presented with a focus on herd risk factors. A total of 4889 animals, ranging in age from 9 to 10 months, from 48 batches of pigs belonging to an equal number of herds, were included in the study. Bronchopneumonic lesions suggestive of enzootic pneumonia (EP-like lesions) were detected in 46.4% of the examined lungs. The EP-like lesion average value for all lungs was 1.03 (95% CI 0.98-1.08), ranging from 0.17 to 2.56 among the 48 batches; 47.5% of lungs showed chronic pleuritis. Dorsocaudal pleuritis suggestive of recovered pleuropneumonia (SPES score ≥2) was found in 25.1% of the lungs. The mean SPES (slaughterhouse pleuritis evaluation system) value of the overall 4889 lungs was 0.83 (95% CI 0.78-0.86). The mean SPES value of the batches ranged from 0.04 to 1.87. The mean Actinobacillus pleuropneumoniae index of all studied batches was 0.61 (95% CI 0.51-0.71), ranging from 0 to 1.84. Blood samples were collected from each herd to evaluate antibody titres to Mycoplasma hyopneumoniae, A. pleuropneumoniae, Aujeszky's disease virus, porcine reproductive and respiratory syndrome virus (PRRSV), and swine influenza virus. Herd characteristics were recorded using a questionnaire given to the farmers. A multivariable analysis was conducted to identify risk factors for pleuritis and EP-like lesions. High dorsocaudal pleuritis was associated with A. pleuropneumoniae seroprevalence and history of A. pleuropneumoniae isolation from pneumonic lungs of dead animals. Vaccination of weaners at 3-5 weeks of age against PRRS using a modified live vaccine was associated with a reduction in the percentage of cranioventral pulmonary consolidation (EP-like lesions).

Concomitant pleural and disseminated tuberculosis in AIDS: immune response or HIV infection compartmentalization?

Although, pleural (PT) and disseminated tuberculosis (DT) have been considered as extreme endpoints of the Th1-Th2 immunological spectrum of the Mycobacterium tuberculosis infection, these conditions can occur together. The presence of PT and DT could be explained by (1) PT as primary condition, with progression of HIV infection possibly leading to dissemination of bacilli located in the pleura; (2) preexisting PT, with reinfection at lower LTCD4+ count explaining the DT form; (3) simultaneous acute PT and DT, considering immune compartmentalization phenomena in pleura. There are several important aspects of the immune response and its compartmentalization in co-infected patients with tuberculosis and HIV. PT and DT should not be always considered as extremes of the immunological response against M. tuberculosis, both diseases together may be explained after the understanding of compartmentalization of immune response. Associations between these entities are not so rare, while they remain incompletely explained. This brief review discusses several points of this contradictory association.

High levels of persistent expression of alpha1-antitrypsin mediated by the nonhuman primate serotype rh.10 adeno-associated virus despite preexisting immunity to common human adeno-associated viruses.

Alpha1-antitrypsin (alpha1AT) deficiency is a genetic disorder causing emphysema if serum alpha1AT levels are <570 microg/ml. We have shown that intrapleural administration of an AAV5alpha1AT vector yielded persistent therapeutic alpha1AT serum levels. Since anti-AAV2 and -AAV5 antibodies prevalent in humans may limit the use of these common serotypes in gene therapy, we screened 25 AAV vectors derived from humans and nonhuman primates for alpha1AT expression following intrapleural administration to mice. The rhesus AAVrh.10 serotype yielded the highest levels and was chosen for further study. Following intrapleural administration, 77% of total body transgene expression was in the chest wall, diaphragm, lung, and heart. Intrapleural administration of AAVrh.10alpha1AT provided long-term, therapeutic alpha1AT expression in mice, although higher doses were required to achieve therapeutic levels in female mice than in male mice. Intrapleural administration of AAVrh.10alpha1AT produced the same levels in AAV2/AAV5-preimmune and naive mice. In mice administered with AAV5alpha1AT and subsequently "boosted" with the AAVrh.10alpha1AT vector, serum levels were increased by 300%. These data indicate that AAVrh.10 is the most effective known AAV vector for intrapleural gene delivery and has the advantage of circumventing human immunity to AAV.

Intrapleural administration of a serotype 5 adeno-associated virus coding for alpha1-antitrypsin mediates persistent, high lung and serum levels of alpha1-antitrypsin.

alpha1-Antitrypsin (alpha1AT) is a serine proteinase inhibitor that protects the lung from degradation by neutrophil proteases. In alpha1AT deficiency, an autosomal recessive disorder resulting from mutations in the alpha1AT (approved symbol SERPINA1) gene, serum alpha1AT levels of < 570 microg/ml are associated with development of emphysema. Adeno-associated virus (AAV) serotype 2 (AAV2) vectors expressing alpha1AT administered intramuscularly or intravenously mediate sustained serum levels of alpha1AT in experimental animals. Since the lung is only 2% of the body weight, AAV vector delivery to the muscle or liver is inefficient, as most of the alpha1AT does not reach the lung. The present study evaluates AAV2- and AAV5-mediated delivery of human alpha1AT (halpha1AT) to C57BL/6 mice using the intrapleural space as a platform for local production of alpha1AT. Intrapleural administration of either an AAV5-halpha1AT or an AAV2-halpha1AT vector achieves higher lung and serum levels of alpha1AT than intramuscular delivery. AAV5-mediated serum and lung alpha1AT levels were 10-fold higher than those achieved by AAV2 delivery via either route. The diaphragm, lung, and heart are the major sites of transgene expression following intrapleural administration of an AAV5 reporter vector. At 40 weeks postadministration, intrapleural administration of the AAV5-halpha1AT vector mediated serum alpha1AT levels of 900 +/- 50 microg/ml, 1.6-fold higher than the accepted therapeutic level of 570 microg/ml. In the context that the pleura is a safe site for administration, intrapleural administration using AAV5 vectors may represent an attractive gene therapy strategy for alpha1AT deficiency in humans.

HIV-associated primary body-cavity-based lymphoma: clinico-biologic features in three patients diagnosed at the same institution.

Primary effusion lymphoma (PEL) is a recently individualized form of non-Hodgkin lymphoma (WHO classification) that mainly develops in HIV infected males, more frequently in homosexuals and advanced stages of the disease (total CD4+ lymphocyte count below 100-200/mL). Occasionally, it appears in others immunodepressive states (such as solid organs postransplant period) and even, although very rarelly, in immunocompetents patients. From a pathogenetic point of view, PEL has been related to Kaposi's sarcoma-associated herpes virus (also named human herpesvirus 8) and to the clinical antecedent of Kaposís sarcoma. Relative unfrequency of this disease, the absence of wide casuistics allowing a better characterization, and its unfavorable outcome, support the need of a deeper knowledge. We present here the clinical-biological findings of three patients that were diagnosed of pleural PEL in our institution in the last two years.

Pleural effusions in human immunodeficiency virus-infected patients. Correlation with concomitant pulmonary diseases.

The objective of our study was to evaluate the prevalence of pleural effusions in patients with the acquired immunodeficiency syndrome, to correlate these effusions with any concomitant pulmonary diseases and to evaluate the role of cytologic examination in the diagnosis of the effusions. Twenty-eight of 389 (7.2%) human immunodeficiency virus-infected patients had pleural effusions and 27 of the 28 were suffering from concomitant pulmonary diseases. Those diseases were bacterial pneumonia (9), mycobacterial infection (7), non-Hodgkin's lymphoma (4) and Kaposi's sarcoma (2). Pneumocystis carinii pneumonia was diagnosed in two patients, and cytomegalovirus pneumonitis and pulmonary aspergillosis and small cell carcinoma in one patient each. Cytologic examination of pleural effusions provided conclusive diagnoses of mycobacterial infection in 2 of the 7 patients, of non-Hodgkin's lymphoma in 4 and of P carinii infection in 2.