Ultrastructural localization of acid phosphatase in immunologically defined neoplastic lymphocytic cells and hairy cells. A comparison between two different substrates.

The subcellular localization of acid phosphatase (AcP) in various immunologically-defined neoplastic lymphoid cells including hairy cells was investigated by electron microscopy. 2 substrates, naphthol-AS-BI-phosphoric acid (naphthol-AS-BI-P) and sodium beta-glycerophosphate, were compared. By incubation in naphthol-AS-BI-P containing medium, the reaction product was found located in granules, vesicles, the Golgi apparatus, the rough ER including the nuclear envelope in the cells of T ALL, T CLL and HCL. A typical pattern of reaction was observed for each of these disorders: enzyme-positive Golgi membranes and neighbouring granules, clustered in the nuclear notch in T cell-derived lymphoblasts; enzyme-positive granules around Gall bodies, aggregated paranuclearly in T CLL lymphocytes and enzyme-positive scattered cytoplasmic granules and vesicles in hairy cells. Enzyme activity was occasionally seen in singly-occurring granules in the cells of cALL, B CLL and B PLL, rarely in other substructures. With the Gomori method using beta-glycerophosphate as substrate, the enzyme reaction was limited primarily to lysosomal sites and was seldom observed in other organelles. Tartrate-resistant AcP was found in the majority of hairy cells and in a few prolymphocytes, located in the same structures as AcP without tartrate.