Daniela Pasqualetti

The lymphoproliferative disease of granular lymphocytes. A heterogeneous disorder ranging from indolent to aggressive conditions

A multiparameter analysis, which included the evaluation of clinical features, cell morphology, karyo‐type, phenotypic and functional immunologic findings, and T‐cell receptor beta‐chain configuration was performed on 34 patients with lymphoproliferative disease of granular lymphocytes (LDGL). The two‐fold aim of the study was to identify the most useful tools that would more accurately characterize these patients and to deal with the problem of classifying these lymphoproliferative disorders. The data presented in this article suggest that a single parameter may not be sufficient to define the nature of the proliferating cells or to predict the clinical course of the disease and prognosis for the patient. The use of a multiparameter approach, however, may reach this goal, thus providing important prognostic and therapeutic information. Our study supports the concept that lymphoproliferative disease of granular lymphocytes is a heterogeneous disorder that ranges from indolent and possibly reactive conditions to the manifestation of aggressive malignancies.

CD7 positive acute myeloid leukaemia: a subtype associated with cell immaturity.

Seventeen patients with acute myeloid leukaemia (AML) whose blasts co‐expressed the T‐cell associated CD7 antibody were identified among 160 consecutive AML cases. Fourteen had FAB defined AML according to morphocyto‐chemical criteria, whereas three patients were classified as ‘MO’ on the basis of immunophenotype. The incidence of CD7 positivity was particularly significant in the less differentiated subtypes MO and M1 compared with other FAB groups (P < 0.001). In all cases the myeloid determinants CD13 and/or CD33 were associated with CD7 expression. Other B‐lymphoid (CD10, CD19) or T‐lymphoid (CD2, surface and cytoplasmic CD3) markers were analysed and found to be negative. Five out of 15 cases examined were TdT+. Clonal rearrangements of the immunoglobulin heavy chain (IgH) and/or T‐cell receptor (TcR) β chain genes were identified in only three out of 13 cases. Among these, one out of five coexpressing TdT showed IgH rearrangement when analysed at the DNA level.

Immunological definition of acute promyelocytic leukemia (FAB M3) : a study of 39 cases

Acute promyelocytic leukemia (FAB‐M3) is a distinct entity among acute non‐lymphoid leukemias (ANLL) with peculiar morphological, biological, clinical and prognostic features. An atypical form of M3 (M3v) could be confused with other FAB ANLL and therefore the diagnosis of this variant requires ultrastructural analysis and/or cytogenetic study and/or selective gene rearrangement studies. The immunological phenotype of blast cells in 39 APL patients was studied at diagnosis. The diagnosis of M3 FAB type was ascertained in 32 and the diagnosis of M3v in 7 cases. Using a large series of monoclonal antibodies (mAb), the APL blast cells were B and T cell antigens‐negative, HLA‐DR constantly negative, CD 13‐ and/or CD33‐positive, CD9‐positive. Among ANLL this phenotype seems to be closely related to APL both in M3 type and M3v subtype. Because the diagnosis of APL (M3 or M3v) is important in order to establish the specific therapeutic approach, the discriminant capacity of the immunological typing to identify M3 and mainly M3v (hypogranular) could be determinant for a “quick” diagnosis.

Rearrangements of the RAR‐α gene in acute promyelocytic leukaemia:

Summary We have used genomic probes which specifically recognize DNA rearrangements of the RAR‐α locus on chromosome 17q21 in patients with acute promyelocytic leukaemia (APL) and acute myeloid leukaemia (AML) subtypes. Molecular data were examined in comparison with morphological and immunophenotypic characterization at diagnosis in 20 hypergranular FAB M3 cases, five microgranular APL (M3v), 51 non‐M3 AML and 12 myeloid CML blast crises.

Characterization of two patients with lymphomas of large granular lymphocytes.

Two patients with non cutaneous well‐differentiated lymphocytic lymphoma with leukemic spread are reported. The large majority of their peripheral blood mononuclear cells (PBMC) formed rosettes with sheep erythrocytes, had receptors for the Fc portion of IgG, and an enzymatic profile of relatively mature T‐cells. These cells were morphologically characterized as large granular lymphocytes. Studies with monoclonal antibodies in one of the cases showed an OKT3+, OKT10‐, OKT4‐, OKT8‐, HNK‐1‐, OKM1+ phenotype, whereas PBMC from the other case were OKT3+, OKT10‐, OKT4‐, OKT8+, HNK‐1+, OKM1‐. PBMC from the first patient were able to suppress in vitro B‐cell differentiation and were capable of a strong antibody dependent cellular cytotoxicity (ADCC) activity. Natural killer (NK) activity was reduced. Cells from the other patient who was hypogammaglobulinemic, exerted suppressor activity in immunoregulatory assays, and showed ADCC and NK activity. These data support the existence of LGL lymphomas consisting of the proliferation of mature appearing cells capable of functional activity.

A population of sheep rosetting cells lacking T- and monocytic-specific antigens, as detected by monoclonal antibodies.

Abstract In the present report we describe the immunological features of peripheral blood mononuclear cells (PBMC) isolated from two patients with hematological disorders. The majority of cells from both patients, although capable of rosetting with sheep erythrocytes, lacked T cell-specific or myelomonocytic-specific antigens, as detected by a large panel of monoclonal antibodies. High proportions of PBMC from both patients had receptors for the Fc portion of IgG and were able to strongly exert cytotoxic/suppressor activities. These cells, showing some distinctive morphological features (namely the presence of granules in their cytoplasm) at the electron microscope level, appear to represent a discrete subset of PBMC, whose lineage, presence in normal donors, and functional properties are still to be defined.

Immunophenotyping of acute myeloid leukaemia: Relevance of analysing different lineage-associated markers

SummaryThe immunophenotype of 135 previously untreated patients with FAB defined acute myeloid leukaemia (AML) was studied at diagnosis. The panel of reagents included monoclonal antibodies (MoAb) recognising myeloid-associated determinants (CD11, CD13, CD14, CD33 and others) as well as MoAb directed towards lymphoid antigens (CD7, CD10, CD19) and TdT. The results indicate that CD13 and/or CD33 are consistently expressed in AML and only rarely in ALL blasts (131/135 +ve cases, versus 4/130 in ALL). Lymphoid antigen expression was rarely detected when CD10 and CD19 were investigated in AML (0.9% and 2% +ve cases, respectively), whereas significant positivities were found for TdT and CD7 (20% and 10% respectively). Concerning FAB subtypes, two new MoAb (LAM3 and LAM7) proved very useful in the specific recognition of AML with monocytic features. The phenotype CD13+ and/or CD33+, CD9+, HLA-DR− was found to be almost exclusive for M3 AML. The response to induction chemotherapy was analysed in CD7+ and in TdT+ patients. In the latter group a statistically significant lower response rate was found with respect to TdT-ve-AML patients.

Lymphocyte T subsets and natural killer cells in Italian and Philippino blood donors.

Background and Objectives The characterization of lymphocyte subsets in blood donors has been utilized to determine the normal ranges that can be related to race. A study was performed in blood donors from two racial groups – Caucasian (Italians) and Asian (Philippinos) – to define respective T‐lymphocyte subsets and levels of cytokines.

Relationship between Sustained Reductions in Plasma Lipid and Lipoprotein Concentrations with Apheresis and Plasma Levels and mRNA Expression of PTX3 and Plasma Levels of hsCRP in Patients with HyperLp(a)lipoproteinemia.

The effect of lipoprotein apheresis (Direct Adsorption of Lipids, DALI) (LA) on plasma levels of pentraxin 3 (PTX3), an inflammatory marker that reflects coronary plaque vulnerability, and expression of PTX3 mRNA was evaluated in patients with hyperLp(a)lipoproteinemia and angiographically defined atherosclerosis/coronary artery disease. Eleven patients, aged 55 ± 9.3 years (mean ± SD), were enrolled in the study. PTX3 soluble protein levels in plasma were unchanged by 2 sessions of LA; however, a downregulation of mRNA expression for PTX3 was observed, starting with the first session of LA (p < 0.001). The observed reduction was progressively increased in the interval between the first and second LA sessions to achieve a maximum decrease by the end of the second session. A statistically significantly greater treatment-effect correlation was observed in patients undergoing weekly treatments, compared with those undergoing treatment every 15 days. A progressive reduction in plasma levels of C-reactive protein was also seen from the first session of LA, with a statistically significant linear correlation for treatment-effect in the change in plasma levels of this established inflammatory marker (R 2 = 0.99; p < 0.001). Our findings suggest that LA has anti-inflammatory and endothelium protective effects beyond its well-established efficacy in lowering apoB100-containing lipoproteins.

Deficiency of lymphocyte lectin-dependent cytotoxicity in myelodysplastic syndromes.

We studied a group of patients with myelodysplastic syndromes (MDS) for surface markers and cytotoxic activities of peripheral blood mononuclear cells (PBMNC). The results indicate a significant increase in the total count of CD11b+, Leu7+ and CD16+ with a percent reduction in CD4+. A reduction in PHA-induced cellular cytotoxicity (PHA-ICC) and NK activity were found. A similar phenotype was found both in refractory anemia (RA) and (RA) with excess of blasts (RAEB/RAEB-t). However, the functional activities reached the normal level only in RA patients; while in RAEB/RAEB-t patients a significant reduction was detected in PHA-ICC and NK activity.