Hairy cell leukemia. Immunological study.

The study has been performed on peripheral blood and splenic malignant cells from 16 patients with hairy cell leukaemia (HCL). The cell surface markers were identified by rosette techniques and using monoclonal antibodies (m Ab). The surface markers' expression of the hairy cells (HC) varied. The E receptors, the T-cell antigens, the HLA-DR antigens and smIgG were either expressed or not according to the affected organ, the progress of illness, or the treatment. The surface pattern changed sometimes in the same patient during the progress of illness. These observations demonstrate that HCL is a unique disease with malignant cells characterized by a marked variability of the cell surface markers. To demonstrate the ability of hairy cells to bind labile smIgG, the cells were studied by affinity chromatography on SpA-Sepharose 6MB and by ES-rosette assay. The percent of cells bound on SpA-Sepharose varied between 6% and 66%, representing the hairy cells with labile-bound smIgG. With affinity chromatography it was also possible to separate the hairy cells with a special phenotype: T3+ T4+ T8+ T11+ surface membrane labile-bound IgG+ (11gG+) FcR+, HLA-DR+ EACD+ (Ripley rosette forming cells), resembling a normal subset of large granular lymphocytes (LGL). The percentage of these cells varied between 60% and 86% of the bound cells. These observations suggest that in HCL, the malignant transformation might involve a common progenitor for the B, T and LGL lineages, the hairy cell being a hybrid type of malignant cell. Its main immunological peculiarity is the marked mobility of the surface membrane structures and hence the lability (plasticity) of the surface markers' expression.

Chronic lymphocytic leukemia and Hodgkin's disease in the same patient: a report of two cases.

Two cases with coexistent chronic lymphocytic leukemia and Hodgkin's disease are reported. The first appeared disease was the chronic lymphocytic leukemia. The eventual influence of this disease on the development of the Hodgkin's disease is discussed.

Acute promyelocytic leukemia with T-cell markers and particular response to treatment. Report of a case.

A case of acute leukemia with atypical malignant cells is reported. The clinical picture and coagulation studies were consistent with a disseminated intravascular coagulation syndrome. Morphologically, the leukemic cells from the peripheral blood and bone marrow showed azurophilic granules. More than 80% of cells were hypergranulated, resembling the macrogranular type of promyelocytes. Ultrastructural studies and the pattern of endogenous peroxidase were consistent with the microgranular type of promyelocytes in about 20% of the leukemic cells. Auer bodies were present in both types of atypical promyelocytes. Cytochemically, the whole malignant population exhibited intense peroxidase activity. Studies with monoclonal antibodies showed that about 45% of the proliferating cells expressed T-cell markers T3, T4, T8 and T11, but the cells were not reactive with OKM1 monoclonal antibodies. The chemotherapy for acute promyelocytic leukemia was inefficient, and the prompt disappearance of the blood abnormalities was observed only when chemotherapy for acute lymphoblastic leukemia was started. Therefore, it seems that in some cases of leukemia with hybrid types of malignant cells the morphological features determine the clinical picture, while the patient's response to the therapy is conditioned mainly by the cell surface phenotype.

[Acute lymphoblastic Ph1-positive leukemia with a hybrid phenotype. The significance of the Ph1 anomaly and the hybrid phenotype]. / Leucemia acuta limfoblastica Ph1 pozitiva cu fenotip hibrid. Semnificatia anomalie Ph1 si a fenotipului hibrid.

The present paper reports on a case of acute lymphoblastic leukemia with t(9q+; 22q-) and surface markers specific of the B and T lymphoid line (hybrid phenotype). The fundamental (genotypical and phenotypical) and practical aspects (nosologic and therapeutical aspects) of this particular subtype of Ph1-positive acute leukemia and hybrid phenotype are discussed.

Particular ultrastructural aspects in some splenectomized cases of hairy cell leukemia.

Some peculiar ultrastructural aspects of hairy cells obtained from the examination with SEM and TEM are presented. Images of erythrocyte rosette-formation around hairy cells in spleen as well as some additional data on the biogenesis of ribosome-lamellae complexes are reported. Some considerations on the origin of hairy cells are added.