Lymphocyte autofluorescence: A screening procedure for neurodegenerative diseases

We examined the buffy coats from 12 consecutive patients with neurodegenerative diseases to determine the value of autofluorescence study by fluorescence microscopy in parallel with electron microscopy, as a rapid and inexpensive screening procedure for lymphocyte inclusions characteristic of neuronal ceroidlipofuscinoses. Four patients (3 with neuronal ceroidlipofuscinoses and 1 with Hallervorden-Spatz syndrome) had discrete, yellow-orange, 1-2 μm autofluorescent granules in the cytoplasm of some lymphocytes. These granules corresponded to characteristic inclusions of neuronal ceroidlipofuscinoses demonstrated by electron microscopy. Five patients (4 undiagnosed or nonspecific disease, and 1 with Leber congenital amaurosis) had hazy green cytoplasmic autofluorescence which correlated with parallel tubular arrays in lymphocytes. The 3 patients with no autofluorescence had no ultrastructural lymphocytic inclusions. We conclude that buffy coat autofluorescence is a rapid and inexpensive method of identifying specimens that require electron microscopic confirmation, and the absence of autofluorescence of lymphocytes in a buffy coat specimen eliminates the necessity for electron microscopic examination. However, characteristic ultrastructural inclusions associated with neurodegenerative diseases may occur in other tissues, such as skin and conjunctiva.