Wallach's Interpretation of Diagnostic Tests: Pathways to Arriving at a Clinical Diagnosis (1112 page)

   Nonspecific (α-naphthyl butyrate or α-naphthyl acetate) esterase identifies monocytic cells but does not stain granulocytes or eosinophils. These two stains may be used to identify leukemic lineage.

   Iron stain (used as Prussian blue reaction). It identifies iron in nucleated red cells (either as siderocytes or as ringed sideroblasts [myelodysplastic syndromes]); it also identifies Pappenheimer bodies in erythrocytes (RBCs, Table 16.73).

   Periodic acid–Schiff (PAS): Detects intracellular glycogen and neutral mucosubstances, which are found in most hematopoietic cells. It is helpful in the diagnosis of erythroleukemia because of the intensity of its diffuse staining in primitive erythroid cells.

   Limitations

   Poorly prepared smears may be difficult to evaluate accurately.

PHOSPHATE, BLOOD

   Definition

   Phosphate is used in the synthesis of phosphorylated compounds. It accompanies glucose into cells. The total body content in normal adults is approximately 700–800 g. About 80–85% of phosphate is contained in bones; the remaining 15–20% is in ICF in tissue as organic phosphates (phospholipids, nucleic acids, NADP, ATP). Only 0.1% is in the ECF as inorganic phosphate, and only this fraction of phosphorus is measured in routine clinical settings.

   
Normal range:
see Table 16.65.

TABLE 16–65. Normal Ranges for Phosphate

   Use

   Monitoring of blood phosphate level in renal, endocrine, and GI disorders

   Interpretation

Increased In

   Acute or chronic renal failure (most common cause) with decreased GFR