title: Periodic acid-Schiff reaction changes during the course of relapsing lymphoblastic leukaemia.
abstract: Bone marrow smears taken at diagnosis and subsequent haematological relapse from 41 patients with lymphoblastic leukaemia (ALL) were compared to assess the proportion of blast cells showing a positive periodic acid-Schiff (PAS) reaction at different stages of the same disease. 20 patients never displayed more than 10% PAS positive blasts at any stage, and of these 8 never had any PAS positivity at all. 7 patients maintained a proportion of PAS positive cells over 10% of the total but with no loss or gain in the numbers of such cells. 14 patients showed a significant change in the PAS reaction during the course of their disease, 7 showing a marked reduction in PAS positive cells, and 7 showing an equally marked increase. From these results it seems that the PAS reaction does not identify a sub-type of ALL or mark the degree of differentiation of a given case. It could be indicative of a specific stage of the lymphoblast mitotic cycle.
mesh_terms: D000970:Antineoplastic Agents / Q000627:therapeutic use; D001853:Bone Marrow / Q000473:pathology*; D006651:Histocytochemistry; D006801:Humans; D007945:Leukemia, Lymphoid / Q000188:drug therapy / Q000473:pathology*; D010503:Periodic Acid-Schiff Reaction; D011379:Prognosis; D012075:Remission, Spontaneous
chemical_list: D000970:Antineoplastic Agents