Blood diseases, acid phosphatase elevation

The substrate phenyl phosphate, which is hydrolyzed by the serum acid phosphatases originating from many tissues, has been used in most of the published studies. Total serum acid phenylphos-phatase is elevated in diseases of the liver, disease of bone such as Paget s disease, and several blood dyscrasias, especially those involving platelets (99>100). 

Red blood cells also contain sufficient acid phenylphospha-tase for mild hemolysis to cause false elevations. Therefore, inhibitors such as ethanol, formaldehyde, copper sulfate> and 1-tartrate have been used to inhibit selectively the enzyme of one or more tissues and enhance the specificity of the test (101). Ethanol is unsuitable because it inhibits the enzyme from erythrocytes and prostate simultaneously, and because it yields serum activities which correlate poorly with prostatic disease. Formaldehyde inhibits the erythrocytic enzyme and has been said to yield clinically satisfactory results. The copoper resistant acid phosphatase of serum is elevated by metastatic carcinoma of the breast, as well as by other metastatic cancers, and is also elevated by a wide variety of non-cancerous diseases. 

Lysis of formed blood elements other than erythrocytes may produce elevations in serum or plasma constituents. Platelet breakdown during blood collection can introduce enzymes into the plasma (Z3). Aldolase activity is very high in platelets (Dl), and elevations of acid phosphatase in myeloproliferative disease are probably the result of platelet lysis (B6). 

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