The Hemalog D automated differential counter in the diagnosis of hairy cell leukemia

Flow cytochemical patterns of white blood cells in human haematopoietic malignancies. I. Acute leukaemias

Peripheral blood samples from 118 patients with acute leukaemia (68 untreated; 50 treated) were measured with the Technicon H-6000 automated haematology analyser. This instrument provides, in addition to measurements of the classical haematology parameters (i.e. cell counts, haemoglobin concentration, etc.), a differential count on 10(4) WBC effected by means of flow cytochemistry (peroxidase content) and volume (light scatter) discrimination. Disregarding RBC and platelet counts and their volume distribution profiles, the most important diagnostic parameters for leukaemic disease were the WBC count, the WBC differential count, and the proportions of large unstained cells (LUC) and high peroxidase (HPX) cells obtained by the automated differential count as well as the mean value of the WBC peroxidase content distribution (MPA). Granulocytic leukaemias had lower MPA than normal and lymphocytic leukaemias had MPA values above normal. M1 leukaemias were also characterized by large proportions of LUC and low fractions of HPX, while M2 leukaemias showed low LUC with high HPX. M3 leukaemias had low LUC and very high HPX. M4 leukaemias had large LUC and 'monocytic' components and a modest fraction of HPX. M5 leukaemias had very large numbers of LUC, 'monocytes' and 'lymphocytes' and a normal HPX. For M1 leukaemia, the presence of less than 7% LUC following induction treatment was related to morphological changes of normal cells induced by chemotherapy while LUC above 10% usually indicated unsuccessful induction associated with the presence of residual blasts. If treatment was successful, M2 and M3 leukaemias characteristically decreased their HPX population. All M4 leukaemias studied by us failed to enter remission and continued to display high proportions of HPX and LUC. Similarly, most M5 leukaemias had a poor response to treatment and always showed a very high proportion of LUC. Untreated lymphocytic leukaemias demonstrated high LUC, normal HPX and a high proportion of 'lymphocytes'. Hairy cell leukaemias showed almost equal proportions of 'lymphocytes' and LUC. Successful chemotherapy of all lymphoid leukaemia entities was associated with rapid decreases in LUC, slower decrements of 'lymphocytes' and moderate and transient increments in HPX. Thus, flow cytochemistry can assist not only in the segregation of acute leukaemias along with FAB classification with nonmorphologic criteria, but also in the follow up of patients with these diseases.

Hairy cell leukemia

Hairy cell leukemia is a chronic lymphoproliferative disorder that has been recognized as a separate clinical pathologic entity for the last 25 years. After a decade of discussions about the origin of the neoplastic cell, it has now been well established that hairy cells represent a certain, rather mature stage of B-cell differentiation. Evidence for this has been derived from studies using immunophenotyping with monoclonal and polyclonal antibodies, cytochemistry, and immunoglobulin gene rearrangement. For many years, splenectomy was the only therapy of proven value in hairy cell leukemia. For patients who showed insufficient response to the operation, chemotherapy with low-dose alkylating agents was moderately successful, whereas polychemotherapy often resulted in excessive toxicity. More recently, therapy with alpha-interferon has been shown to be very promising, whereas deoxycoformicin may be an attractive alternative. These new advances in immunology and therapy are reviewed.

Flow cytometric analysis of hairy cell leukemia using right-angle light scatter

We report on an easy and reliable method for the enumeration of the typical cells present in the blood, bone marrow, and spleen of patients with hairy cell leukemia. Samples of five patients were analyzed. In three patients, the hairy cells were very accurately followed during treatment with alpha-interferon, using right-angle light scatter to differentiate them from other leukocytes present in total blood. Excellent correlation was obtained with the microscopic hairy cell enumeration. Additional verification by cell sorting and immunofluorescence studies confirmed these findings.