The malignant mononuclear cells of leukemic reticuloendotheliosis (hairy cell leukemia) are resistant to inhibition by tartaric acid. There is evidence that the reaction is not entirely specific because tartrate-resistant acid phosphatase (TRAP) reactions have been reported in prolymphocytic leukemia and malignant lymphoma and in some cases of infectious mononucleosis.
Obtain venous blood sample (5 mL) or bone marrow smear. Label the specimen with the patient’s name, date and time of collection, and test(s) ordered.
Incubate blood smear with TRAP, counterstain, and examine microscopically.
TRAP is present in the leukemic cells of most patients with hairy cell leukemia; 5% of patients with otherwise typical hairy cell leukemia lack the enzyme.
TRAP occasionally occurs in malignant cells of patients with lymphoproliferative disorders other than hairy cell leukemia.
Histiocytes have weakly positive reactions.
Pretest Patient Care
Explain test purposes and procedures. Assess for history of signs and symptoms of leukemia.
Follow guidelines in Chapter 1 for safe, effective, informed pretest care.
Posttest Patient Care
Review test results; report and record findings. Modify the nursing care plan as needed. Counsel the patient regarding abnormal findings; explain the need for possible follow-up testing and treatment.
Follow guidelines in Chapter 1 for safe, effective, informed posttest care.