Partial peroxidase deficiency in neutrophils and eosinophils associated with neurologic disease. Histochemical, cytochemical and biochemical studies.

Partial peroxidase deficiency was discovered by means of automated continuous-flow cytochemistry (Hemalog D) in the neutrophils and eosinophils of a patient admitted for evaluation of the gradual onset of intellectual deterioration. Wright's stain and routine benzidine peroxidase reaction on peripheral blood smears showed a normal differential count and peroxidase activity, respectively, but smears stained for peroxidase using 4-chloro-1-naphthol, the reagent used in Hemalog D, showed absence of enzymatic activity in neutrophils and eosinophils. Electron microscopy using the Graham-Karnovsky diamino-benzidine method confirmed these findings, demonstrating a new pattern of peroxidase deficiency in which a decreased number of peroxidase-positive granules were found in all neutrophils and, surprisingly, also in eosinophils. Bio-chemical studies also showed that the apparent deficiency is due to an abnormal proportion of "insoluble" peroxidase. These results and the clinical findings for the patient are consistent with the diagnosis of ceroid lipofuscinosis (Kuf's disease).