According to a recent article published in The Lancet, a marker identified by gene profiling referred to as Annexin A1 (ANXA1) can help distinguish hairy cell leukemia from different kinds of leukemia.
Hairy cell leukemia is a type of cancer that affects the immune system in which lymphocytes, the cells responsible for immunity, replicate abnormally. The disease is often characterized by low blood counts, enlargement of the spleen and circulating cancer cells, which under microscopic examination have a “hairy” appearance. These cancer cells may infiltrate the spleen, liver and bone marrow. Diagnosis of hairy cell leukemia can be confused with other types of immune cancers, which may be treated in a different manner. Therefore, researchers have been evaluating ways in which to make diagnosis of hairy cell leukemia more accurate.
Recently, researchers conducted a clinical study involving gene profiling of cancer cells to determine is a possible relationship existed between genes or protein expression that was specific to hairy cell leukemia. The researchers evaluated 500 tissue samples in this study and found the ANXA1 protein was expressed in 97% of hairy cell leukemias (62 patients). The remaining 463 specimens were ANXA1-negative, making the test 100% sensitive and specific for hairy cell leukemia. These results validate the results of gene profiling by showing that ANXA1 is expressed in solely hairy cell leukemia and not in other cancers affecting the immune system, with the exception of variant hairy cell leukemias, which are rare and were not included in the gene profiling.
Because of the low cost, simplicity, and high detection rates, the researchers have suggested that detection of ANXA1 be added to the diagnostic evaluation of patients who may have hairy cell leukemia or related diseases. Patients are encouraged to speak to their physicians regarding testing related to their specific situation.
Reference: Brunangelo F, Enrico T, et al. Simple Diagnostic Assay for Hairy Cell Leukemia by Immunocytochemical Detection of Annexin A1(ANXA1). The Lancet. 2004; 363: 1869-1871.