Leukocytes acid phosphatase

The most clearly documented role lor selenium is as a necessary component of glutathione peroxidase. Selenium is also involved in the functions of additional enzymes, e.g.. type I iodoihvronine deiodinase. leukocyte acid phosphatase, and glucuronidases. A role for selenium in electron transfer has been suggested as has involvement in nonheme iron proteins. Selenium and vitamin b appear to be necessary lor proper functioning of lysosomal membranes. A role for selenium in metabolism of thyroid hormone has been continued. 

The acid phosphatase activity of leukocytes was studied by Valentine and Beck (B8, VI) in 1951. There appear, however, to have been no significant attempts to purify the enzyme from this source, or to describe its characteristics. Recently, Szajd and Pajdak (S32) indicated the isoenzyme characteristics of leukocyte acid phosphatase, and Li and his associates (L7, L8) studied this problem in greater detail. They suspended a leukocyte preparation, carefully separated from blood, in 5% Triton X-100 to yield a final concentration of 10 X 10 cells per milliliter and subjected the suspension to six cycles of alternate freeze-thaw treatment. The suspension was then centrifuged at lOOOp for 15 minutes at 4°C, and the supernatant was used for electrophoretic studies. Specimens centrifuged at 100,000p for 15 minutes gave the same results. Electrophoresis was carried out at 4°C for 60 minutes on a 7.5% acrylamide gel matrix containing 0.5% Triton X-100 at pH 4.0 with a current of 4 mA per tube. The substrate was -naphthyl phosphate. 

The values for the normal leukocyte acid phosphatase activity and the normal isoenzyme pattern will be described in connection with the alteration of these in various hematologic and hematopoietic disorders. 

Leukocytic Acid Phosphatase Activity in Hematologic AND Hematopoietic Disease... 

Leukocyte Acid Phosphatase Activity in Various Hematologic Diseases ... 

DeChatelet LR, McCall CE, Cooper MR, Shirley PS. Inhibition of leukocyte acid phosphatase by heparin. Chn Chem 1972 18(12) 1532-4. 

The term serum has been omitted designedly from the title of this section, for we shall be discussing not only alterations of acid phosphatase activity in the serum of patients with nonprostatic disease, but also in the leukocytes of patients with hematologic and hematopoietic disorders and, in some conditions, in certain specialized tissues. 

The acid phosphatase activity of leukocytes was determined by Valentine and Beck (VI) in 1951 and expressed as the amount of phos-... 

Acid Phosphatase in the Leukocytes op Normal Subjects and Patients... 

In addition to the four bands of acid phosphatase isoenzyme activity in normal leukocytes, two other isoenzymes may appear in leukemia. In a case of acute granulocytic leukemia with 100% blast forms, only one electrophoretic band of activity was manifest this migrated between normal band 3 and 4 and was therefore designated 3b. In a case of leukemic reticuloendotheliosis with 98% reticulum cells, only one, and this a strongly staining band, was present this migrated anodically beyond No. 4 and was therefore designated No. 5 (L8). 

As was noted above, a preparation obtained from patients peripheral blood in which 98% of the leukocytes were reticulum cells, showed only one isoenzyme. No. 5, of acid phosphatase activity (L8). In patients with a differential white cell count with lesser numbers of reticulum cells and greater numbers of neutrophiles and lymphocytes, isoenzymes 1, 2, 3, and 4 were also evident. For example, in a case with 54% reticulum cells, 20% neutrophiles, 1% monocytes, and 25% lymphocytes, the relative isoenzyme activities were No. 0, 0% No. 1, 30.8% No. 2, 18.8% No. 3, 9.7% No. 3B, 8.0% No. 4, 10.8% No. 5, 21.9% (L8). 

Szajd, J., and Pajdak, W., Acid phosphatases of normal and chronic granulocytic leukemia/CGL/leukocytes. Proc. Int. Congr. Int. Soc. HematoL, 12lh, New Yorkp. 35 (1968). Abstr. 

The transient and moderate rises in leukocyte alkaline phosphatase and uric acid serum concentrations that are often observed after G-CSF treatment are considered to arise from an increased neutrophil count (SEDA-17, 396). Similarly, serum lactate dehydrogenase and alkaline phosphatase activities are often increased, and this should be interpreted as the consequence of enzyme release after growth factor-induced leukocyte recovery (SED-13, 1115). 

A transient, moderate, and reversible rise in leukocyte alkaline phosphatase, lactate dehydrogenase (LDH) and serum uric acid concentrations is usually observed in cancer patients receiving supportive treatment with GM-CSF or G-CSF. Serum LDH increased from 37 to 85% and there was a linear relation between increased leukocyte production and the rise in serum LDH (32). Increases in serum LDH activity should therefore not be interpreted as indicative of disease progression, unless LDH activity remains high after growth factor withdrawal. 

Concentrations of heparin as low as 1 lU/ml give 80% inhibition of acid phosphatase activity in leukocytes (116). 

The acid phosphatases include all phosphatases that hydrolyze phosphate esters with an optimum pH of less than 7.0. They are present in the lysozymes of the secretory epithelial cells. Although acid phosphatase is produced primarily by the prostate gland, it is also found in erythrocytes, platelets, leukocytes, bone marrow, bone, liver, spleen, kidney, and intestine. 

Macrophage, leukocyte, lymphocyte Acid phosphatase (12), lysozyme (12) Fhytohemagglutinin (9), BCG, serum promoted pinocytosis (12)... 

Fructose-1,6-bisphosphatase deficiency, first describ ed by Baker and Winegrad in 1970, has now been reported in approximately 30 cases. It is more common in women and is inherited as an autosomal recessive disorder. Initial manifestations are not strikingly dissimilar from those of glucose-6-phosphatase deficiency. Neonatal hypoglycemia is a common presenting feature, associated with profound metabolic acidosis, irritability or coma, apneic spells, dyspnea, tachycardia, hypotonia and moderate hepatomegaly. Lactate, alanine, uric acid and ketone bodies are elevated in the blood and urine [11]. The enzyme is deficient in liver, kidney, jejunum and leukocytes. Muscle fructose-1,6-bisphosphatase activity is normal. 

Alkaline phosphatase is an enzyme represented by various isoforms in many tissues such as liver, bone, intestine, placenta, some tumors and in leukocytes. Addition of 1 mM levamisole to the chromogen/substrate will inhibit endogenous alkaline phosphatase activity, with the exception of the intestinal isoform. If necessary, this can be blocked with a weak acid wash, such as 0.03 0.5 N HC1 or 1 M citric acid. 

Registration of adverse effects with Lorenzo s oil has been hampered by the absence of controlled trials. In 22 patients treated for at least 12 months, although Lorenzo s oil did not seem to be beneficial, there were possible adverse effects, such as mild increases in liver enzymes (55%), thrombocytopenia (55%), gastrointestinal complaints (14%), and gingivitis (14%). Furthermore, there were falls in hemoglobin concentration and leukocyte count, and an increase in the plasma alkaline phosphatase concentration the reduction in platelet count did not result in hemorrhage (1). Whether some of the adverse effects of Lorenzo s oil are due to low concentrations of essential fatty acids or caused by reduced dietary fat intake is not known. 

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