case_images: PMC3204617_01
case_images: Tissue sample from 30-year-old primigravida patient exposed to seasonal influenza (H1N1). A) Intervillous (maternal) spaces with clusters/sheets of histiocytes (chronic intervillositis) and fibrotic fetal chorionic villi with Hofbauer cells-histiocytic inflammation (hematoxylin and eosin stain, original magnification x200). B) Dual-stained immunofluorescent assay showing antibodies to influenza A virus (H1N1) (tetramethylrhodamine isothiocyanate, red) and cytokeratin (fluorescein isothiocyanate, green) in intravillous (fetal) and intervillous (maternal) space.
case_images: 09-1895-F1.jpg
case_images: PMC3204617_01_09-1895-F1.jpg
case_images: F1
case_images: Microscopically, histiocytes were abundant in the maternal space (chronic intervillositis) and were noted within the fetal chorionic villi (Hofbauer cells; Figure 1, panel A). In the placenta, stippled immunofluorescence (Figure 1, panel B) was noted in the histiocytes of the intervillous space (maternal) and fetal intravillous histiocytes.
case_images: Tissue sample from 30-year-old primigravida patient exposed to seasonal influenza (H1N1). Electron microscopy (original magnification x70,000) of maternal intervillous space and fetal chorionic villi, showing intranuclear viral transcription aligning along the nuclear envelope-electron hypodensities (asterisks), and intracytoplasmic viral production in varying stages shown by numerous electron densities (V and ^). Scale bar = 500 nm. Inset: enlarged image of mature virion with capsular projections. Ultrastructural features are characteristic of influenza viruses. Scale bar = 100 nm.
case_images: 09-1895-F2.jpg
case_images: PMC3204617_01_09-1895-F2.jpg
case_images: F2
case_images: Histiocytes identified from the maternal intervillous space and fetal chorionic villi demonstrated characteristics of viral production (Figure 2).