Usefulness of Unicel DxH 800 Cell Population Data in the Detection of Plasmacell Leukemia: 2 Cases Report

Lymphoproliferative disorders (LD) are characterized and described by lymphocyte population with heterogeneous morphological features both in optical microscopy revision and in flow cytometry. Several literature report the clinical usefulness of Cell Population Data (CPD) provided by Beckman Coulter hematology analyzers. Abnormal values of CPD correlate with morphological abnormalities of leukocytes. In this work we present a case report of a plasmacell leukemia analyzed with UniCel DxH800 device. DxH800 performs leukocytes differential with the Flow Cytometric Digital Morphology (FCDM) technology, based on the measurements of Volume (V), Conductivity (C) and 5-angle Scatter light laser (MALS, UMALS, LMALS, LALS, AL2) on cells in their native state. Mean and standard deviation of FCDM measurements are collected in 56 CPD. Normal CPD values were computed from a 42 normal samples.

A 47-years old woman, referring continuous asthenia, was addressed to our lab with clinical suspect of LD with leukocytosis (WBC=17190/μl, LY#=3800). DxH800 analysis confirmed WBC count adding some important comments. WBC histogram showed a big peak in lymphocyte population. Differential values reported neutrophilia and lymphocytosis while scatterplot showed a lymphocyte cluster very close to the neutrophil one. CPD suggested a heterogeneous neutrophil population with low volume and low scatters (MALS, UMALS, LMALS, LALS, AL2 in arbitrary units) respectively of 106, 90, 112, 62, 75 vs normal values of 144, 137, 143, 158, 159. Examination of blood smear showed a lot of lymphocyte with nuclear immaturity and plasmoblast features. Immunophenotype revealed that 63% of the WBC were CD138+/CD38+, CD56+ CD200-, CD27- CD20-. Bone marrow biopsy confirmed the plasmacell leukemia diagnosis.

A 65-years old man was admitted to our department for a light lymphocytosis associated with a IgGk monoclonal component. Immunophenotipic analysis showed a NK proliferation (CD3 50%, CD4 38%, CD8 34%, CD2 92%, CD7 92%, CD16 45%, CD56 48%, CD57 54%). DxH800 analysis reported LY#=3.6/μl and MO#=1,6/μl. LY CPD indicate cells with light signals of degranulation (MALS=56, UMALS=60, LMALS=63 vs normal values of 66, 60 and 63 ) together with abnormal monocyte CPD such as MV=157, MC=136, MALS=79, UMALS=80, LALS=75 vs normal values of 164, 129, 85, 80 and 75 respectively. All this data induced us to look for a mononuclear population different both from lymphocytes and monocytes in the peripheral blood smear. Bone marrow microscopy analysis showed morphologically abnormal cells that were classified as plasmacells after immunophenotyping (CD138+/CD38+, CD56+, CD45-, CD117+, CD20-, CD27-, CD200+. Further immunophenotypic analysis showed in PB 14% of plasmacells CD138+/CD38+/CD45-.

We presented 2 cases report of a plasmacell leukemia whose diagnosis were supported by the useful information of the CPD provided by DxH 800. CPD abnormal values for lymphocytes and monocytes were known to correlate with morphological abnormalites of the cells. For this reason we were triggered to deeply investigate the blood smear of the two patient and we performed the immunophenotyping. This short report confirm the usefulness of CPD provided by UniCel DxH800 as the first check point for the diagnostic route. Moreover we confirm that morphological features in the PB smear discovered during the diagnosis, supported by flow-cytometry data, were properly correlated with CPD values.

Fogli:Instrumentation Laboratory: Employment. Di Gaetano:Instrumentation Laboratory: Employment.