Interferenza analitica sul conteggio dei leucociti
Analytical interference on leucocyte count
AUTORI
Francesco Bondanini2, Maria Grazia Colace1
1UOC Laboratorio HUB 1 - Presidio Ospedaliero Sandro Pertini ASL Roma 2
2UOC Laboratorio HUB 2 - Presidio Ospedaliero Sant' Eugenio ASL Roma 2
ABSTRACT
Analytical interference on leucocyte count
Chronic lymphoproliferative disorders typically affect elderly patients with a median age at the diagnosis of 71 years. These disorders include a number of conditions characterized by an abnormal proliferation of lymphocytes towards a monoclonal lymphocytosis. The case of an 83-year-old man affected by chronic lymphocytic leukemia is presented; the peripheral blood cells count, performed on the analyzer Sysmex XN-20, showed significant differences between the white nucleated red (WNR) and white differentiation (WDF) channels that did not allow the differential counting of leukocytes. On the opposite, the reflex analysis channel white progenitor cell (WPC), returned the correct white blood cell count. Actually, when the peripheral blood sample was diluted (1:5) and resubmitted to analysis, leukocytes count resulting from WNR and WDF analysis channels corresponded to that obtained in the reflex WPC analysis channel on the undiluted sample. To verify if the instrumental anomaly found in the cell counting could be associated to an elevated plasma concentrations of immunoglobulins, a serum protein electrophoresis was performed, showing the presence of four monoclonal components. These data demonstrate that the WPC channel is an important tool for the clinical laboratory, since it is able to give a correct result even when interferents are present.
