Application of fluorescence spectroscopy in the amyloidosis diagnosis: a preliminary report

The aim of this study was to evaluate the usefulness of fluorescence spectroscopy studies in the diagnosis of secondary AA amyloidosis. Histopathological, immunohistochemical and fluorescence spectroscopy evaluations of abdominal fat tissue specimens of 12 patients with rheumatoid arthritis (RA) and secondary amyloidosis were performed. The control group comprised 8 RA patients with clinical suspicion of amyloidosis, unconfirmed in histopathological examination. In 9 cases, the analysis of autofluorescence spectra showed differences between the slices containing amyloid deposits and healthy tissue. A characteristic feature of tissue slices with amyloidosis was the appearance of a second maximum in the fluorescence spectrum chart. In 3 cases, the shape of the fluorescence spectra did not enable an unequivocal differential diagnosis. The histopathological tissue examination remains the gold standard in the diagnosis of amyloidosis. Preliminary results indicate that the fluorescence spectrum analysis can be a diagnosis support method, but to assess its usefulness the group of patients needs to be increased.