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Electron Microscopy of Infectious AgentsCase 3: Adenovirus in Pleural Fluid CulturesCase Presentation This is not just another adenovirus case. This 4 year old male had pancytopenia and marrow evidence of myelofibrosis. He received a bone marrow transplant from a brother who was mismatched for one HLA-A, -B, and -DQ antigen each, but serologically matched for HLA-DR, and was mixed-lymphocyte culture assay compatible. Both brothers were positive for IgG antibody to EBV capsid antigen pre-transplant. Four months post-transplant the patient developed nasal congestion, pulmonary infiltrates, and fever. Throat and stool cultures were positive for adenovirus. A cervical node biopsy was consistent with B-cell lymphoproliferative disease (BLPD). A nasopharyngeal mass was partially resected on day 148 post-transplant, which was also adenovirus culture-positive. Although chemotherapy was administered, the lymphoproliferative disease progressed, and the patient expired 165 days after transplantation. A lymphoblastoid (Mk) cell line was established from a pleural fluid specimen taken at autopsy, and confirmed to be consistent with an EBV-associated malignant B-cell lymphoma by FACScan monoclonal antibody assays (HLA DR, lambda light chains, and B-cell surface antigens CD19, CD20, and CD21 were present). The cell line was positive for EBNA and negative for EBV envelope glycoproteins by immunofluorescent staining, which is characteristic for a latent EBV infection. Histocompatability typing demonstrated the Mk cell line to be of donor origin. Approximately 3x10 6 Mk cells from 3 week old cultures were pelleted by centrifugation and fixed for electron microscopy. |
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 Magnify Image Figure 6 |
Ultrastructurally, the cells had irregular nuclei, few cytoplasmic organelles, and few short microvilli on the cell surfaces. Adenovirus particles were abundant both in the nuclei and dispersed within the cytoplasm in many of the cells. | |
 Magnify Image Figure 7 |
Another interesting finding was nonviral paracrystalline inclusions in the cytoplasm (three such inclusions are seen in figure 6) and in the nucleus. | |
| Discussion | ||
| September 1998 Case-of-the-Month | ||