1. Pleomorphic Structures in Human Blood Are Red Blood Cell-Derived Microparticles, Not Bacteria
- Author
-
Max R. Schroeder, Adam Mitchell, Elizabeth R. Wright, Rebecca S. Dillard, Hong Yi, Charles D. Searles, Zunlong Ke, Jeannette V. Taylor, David S. Stephens, John D. Roback, and Warren D. Gray
- Subjects
0301 basic medicine ,Erythrocytes ,Time Factors ,Physiology ,lcsh:Medicine ,Artificial Gene Amplification and Extension ,030204 cardiovascular system & hematology ,Polymerase Chain Reaction ,law.invention ,chemistry.chemical_compound ,0302 clinical medicine ,Spectrum Analysis Techniques ,law ,Cell-Derived Microparticles ,Medicine and Health Sciences ,Electron Microscopy ,lcsh:Science ,Polymerase chain reaction ,Microscopy ,Multidisciplinary ,medicine.diagnostic_test ,biology ,Human blood ,Transfusion medicine ,Blood Proteins ,Hematology ,Flow Cytometry ,Clinical Laboratory Sciences ,3. Good health ,Body Fluids ,medicine.anatomical_structure ,Blood ,Spectrophotometry ,Cytophotometry ,Cellular Structures and Organelles ,Anatomy ,Research Article ,DNA, Bacterial ,medicine.medical_specialty ,Research and Analysis Methods ,Biomolecular isolation ,Microbiology ,Flow cytometry ,03 medical and health sciences ,Diagnostic Medicine ,medicine ,Humans ,Blood Transfusion ,Vesicles ,Molecular Biology Techniques ,Cell Shape ,Molecular Biology ,Cell Size ,Bacteria ,Transfusion Medicine ,lcsh:R ,Organisms ,Biology and Life Sciences ,Cell Biology ,biology.organism_classification ,DNA extraction ,DNA isolation ,Red blood cell ,MicroRNAs ,Microscopy, Electron ,030104 developmental biology ,chemistry ,Immunology ,lcsh:Q ,Transmission Electron Microscopy ,DNA - Abstract
Background Red blood cell (RBC) transfusions are a common, life-saving therapy for many patients, but they have also been associated with poor clinical outcomes. We identified unusual, pleomorphic structures in human RBC transfusion units by negative-stain electron microscopy that appeared identical to those previously reported to be bacteria in healthy human blood samples. The presence of viable, replicating bacteria in stored blood could explain poor outcomes in transfusion recipients and have major implications for transfusion medicine. Here, we investigated the possibility that these structures were bacteria. Results Flow cytometry, miRNA analysis, protein analysis, and additional electron microscopy studies strongly indicated that the pleomorphic structures in the supernatant of stored RBCs were RBC-derived microparticles (RMPs). Bacterial 16S rDNA PCR amplified from these samples were sequenced and was found to be highly similar to species that are known to commonly contaminate laboratory reagents. Conclusions These studies suggest that pleomorphic structures identified in human blood are RMPs and not bacteria, and they provide an example in which laboratory contaminants may can mislead investigators.
- Published
- 2015