Successful removal of Chlamydia pneumoniae from plateletpheresis products collected using automated leukoreduction hemapheresis techniques.

Chlamydia pneumoniae (Cp) is an obligate intracellular pathogen associated with a variety of maladies. Best known for its involvement in community-acquired pneumonia outbreaks; the potential role of Cp in diverse illnesses is a topic of increasing interest and investigation. Previous studies suggested that white blood cells from normal blood donors harboring this agent may be eliminated through leukoreduction by filtration. Here we examine the ability and efficacy of apheresis-related leukoreduction for its effect on the carriage and potential infectivity of these organisms in the preparation of platelet products. Matched pre-apheresis peripheral blood (PB) samples and product samples obtained from healthy plateletpheresis donors were analyzed for the presence and potential infectivity of Cp organisms by direct smear inspection and tissue culture techniques. Antibody seroreactivity directed towards the organism was assessed using a solid phase immunoassay. Forty-eight percent of the donor blood samples exhibited elevated anti-Cp antibody titers (> or =200). Specimens from 31 (27%) and 34 (30%) of 115 plateletpheresis donors were positive for the presence of Cp organisms in their pre-apheresis PB samples when analyzed by direct smear examination and culture, respectively. Examination of the 115 post-leukodepleted plateletpheresis product samples revealed only two (1.7%) and one (0.009%) product(s) to be smear-positive and culture-positive, respectively. Certain plateletpheresis donors may harbor infectious Cp organisms in circulating WBC. Collections from such donors of apheresis platelet products using standard apheresis leukoreduction strategies appear successful in markedly decreasing or eliminating the organisms found in the final products.

Detection of Chlamydia in the peripheral blood cells of normal donors using in vitro culture, immunofluorescence microscopy and flow cytometry techniques.

BACKGROUND: Chlamydia trachomatis (Ct) and Chlamydia pneumoniae (Cp) are medically significant infectious agents associated with various chronic human pathologies. Nevertheless, specific roles in disease progression or initiation are incompletely defined. Both pathogens infect established cell lines in vitro and polymerase chain reaction (PCR) has detected Chlamydia DNA in various clinical specimens as well as in normal donor peripheral blood monocytes (PBMC). However, Chlamydia infection of other blood cell types, quantification of Chlamydia infected cells in peripheral blood and transmission of this infection in vitro have not been examined. METHODS: Cp specific titers were assessed for sera from 459 normal human donor blood (NBD) samples. Isolated white blood cells (WBC) were assayed by in vitro culture to evaluate infection transmission of blood cell borne chlamydiae. Smears of fresh blood samples (FB) were dual immunostained for microscopic identification of Chlamydia-infected cell types and aliquots also assessed using Flow Cytometry (FC). RESULTS: ELISA demonstrated that 219 (47.7%) of the NBD samples exhibit elevated anti-Cp antibody titers. Imunofluorescence microscopy of smears demonstrated 113 (24.6%) of samples contained intracellular Chlamydia and monoclonals to specific CD markers showed that in vivo infection of neutrophil and eosinophil/basophil cells as well as monocytes occurs. In vitro culture established WBCs of 114 (24.8%) of the NBD samples harbored infectious chlamydiae, clinically a potentially source of transmission, FC demonstrated both Chlamydia infected and uninfected cells can be readily identified and quantified. CONCLUSION: NBD can harbor infected neutrophils, eosinophil/basophils and monocytes. The chlamydiae are infectious in vitro, and both total, and cell type specific Chlamydia carriage is quantifiable by FC.

The bronchial lavage of pediatric patients with asthma contains infectious Chlamydia.

There has been a worldwide increase in the incidence of asthma, and the disease has greatly impacted the public health care system. Chlamydia pneumoniae has been reported as a possible contributing factor in asthma. The organism has been detected by polymerase chain reaction (PCR) in bronchial tissue, but there has been no direct evidence of viability. To determine the frequency of viable Chlamydia in children, blood and bronchoalveolar lavage were collected from 70 pediatric patients undergoing flexible fiberoptic bronchoscopy. Forty-two of these patients had asthma, whereas the remaining patients had various respiratory disorders. Fifty-four percent (38) of the bronchoalveolar lavage samples were PCR-positive for Chlamydia, and 31% (22) of the PCR-positive samples were positive when cultured on macrophages. Twenty-eight samples (40%) and 14 samples (20%) of the PCR- and culture-positive samples, respectively, were from patients with asthma. Culture of the blood samples revealed that 24 (34.3%) of 70 were positive for Chlamydia compared with 8 (11%) of 70 matched nonrespiratory control subjects (p < 0.01); 17 (24%) of the positive blood cultures from the respiratory group were from patients with asthma. Elevation of total IgE was strongly associated with lavage culture positivity for Chlamydia. We therefore conclude that viable Chlamydia pneumoniae organisms are frequently present in the lung lavage fluid from this cohort of predominantly asthmatic pediatric patients.