G. De Rossi

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.

DNA copy-number abnormalities do not occur in infant ALL with t(4;11)/MLL-AF4

The pathogenesis of infant acute lymphoblastic leukemia (ALL) is still not well defined. Short latency to leukemia and very high concordance rate for ALL in Mixed-Lineage Leukemia (MLL)-positive infant twins suggest that the MLL rearrangement itself could be sufficient for overt leukemia. Attempts to generate a suitable mouse model for MLL-AF4-positive ALL did not thoroughly resolve the issue of whether cooperating mutations are required to reduce latency and to generate overt leukemia in vivo. In this study, we applied single-nucleotide polymorphism array technology to perform genomic profiling of 28 infant ALL cases carrying t(4;11) to detect MLL-cooperating aberrations hidden to conventional techniques and to gain new insights into infant ALL pathogenesis. In contrast to pediatric, adolescent and adult ALL cases, the MLL rearrangement in infant ALL is associated with an exceptionally low frequency of copy-number abnormalities, thus confirming the unique nature of this disease. By contrast, additional genetic aberrations are acquired at disease relapse. Small-segmental uniparental disomy traits were frequently detected, mostly constitutional, and widely distributed throughout the genome. It can be argued that the MLL rearrangement as a first hit, rather than inducing the acquisition of additional genetic lesions, has a major role to drive and hasten the onset of leukemia.

Increased serum levels of soluble CD44 standard, but not of variant isoforms v5 and v6, in B cell chronic lymphocytic leukemia

The CD44 cell surface proteoglycan participates in a variety of functions including lymphohematopoiesis, lymphocyte homing and tumor metastasis. In addition to the standard form (CD44st), a large family of variant isoforms (CD44v) is generated by alternative splicing of a single gene. Certain CD44v (v5 and V6) are upregulated in the course of neoplastic progression and reflect the metastatic potential of tumor cells. CD44 v6 is expressed in high-grade non-Hodgkin’s lymphoma cells and is released in the serum, thus providing a soluble marker that reflects tumor burden, disease progression and treatment response. Here we show that serum CD44st is elevated in approximately half of B-CLL patients. In contrast, CD44v5 and v6 are detected at normal levels in the large majority of the cases. CD44st serum levels correlate significantly with the number of circulating leukemic B cells and with the levels of another soluble B-CLL marker, β2-microglobulin. Immunoprecipitation analyses of B-CLL sera allow detection of several high molecular weight bands and of a 78 kDa band that represents a soluble form of CD44st and is 4 kDa lower than a similar band (82 kDa) detected in B-CLL cell lysates. Elevated serum CD44st associates with a number of unfavorable prognostic factors such as high peripheral blood lymphocytosis, splenomegaly, advanced disease stage and therapy requirement. A follow-up study indicates that serum levels of CD44st are related to disease status, thus reinforcing our veiw that this molecule may represent a reliable tumor marker in B-CLL.

Adhesion Molecule Expression on B-Cells from Acute and Chronic Lymphoid Leukemias

Adhesion molecule expression on acute and chronic lymphoid leukemia cells of B lineage (B-ALL and B-CLL) may subserve several functions. Adhesion of leukemic cells to endothelial cells and to extracellular matrix components is relevant to homing, trafficking and spread of the malignant cells, and thus to clinical presentation, course and disease prognosis. Adhesive interactions between malignant cells and accessory cells, particularly stromal cells in the bone marrow environment, may support growth of the malignant cells via cytokine-delivered messages. They may also deliver signals that prevent or trigger programmed cell death of tumor cells. Here we review data on the adhesive phenotype of leukemic blasts from pro-B (CALLA +) ALL and of cells from B-CLL cases. We show that expression of certain adhesion molecules may help define disease subsets with distinctive clinical and prognostic features. One adhesion molecule, the lymphocyte homing receptor CD44, allows definition of two groups of B-CLL patients with significantly different survival.

Decreased NK Activity in Hairy Cell Leukemia (HCL): An Analysis at the Cellular Level*

SummaryPeripheral blood lymphocytes (PBL) of eleven patients with Hairy Cell Leukemia were studied for surface phenotype and for NK activity against the K 562 cell line (using both the standard 51Cr Release Assay and the Single Cell Cytotoxicity Assay on poly-L-lysine coated coverslips). A significant reduction in NK activity, target binding cells (TBC) and NK active cells (NKa) was detected. In some cases however, despite a very low percentage of NKa, residual NK activity was observed, suggesting an efficient recycling capacity.

Brain SPET and auditory cortex perfusion. Technical notes and preliminary results

Auditory cortex stimulation was studied by 99Tcm-hexamethylpropyleneamine oxime (HMPAO) single photon emission tomography (SPET) in 11 patients with normal vestibular and auditory tests, as well as computed tomography. Markedly increased temporal and parietal blood flows were found in left brain cortex, contralateral to the stimulus. The right auditory areas showed moderate hyperactivity. The method might be useful for tonotopic mapping of auditory cortex, using various pure tonal stimuli.

PHA-ICC, ADCC and NK in patients with ANLL in CR: Human fibroblastic interferon fails to increase NK-active cell frequency

PHA-ICC, ADCC and NK activity of PBL were studied in ten patients with ANLL in CR and in eighteen normal controls in the presence and absence of HFIF. No statistically significant differences were recorded among the two groups with regard to basic lymphocyte functions. Although the parameters of lymphocyte function remained analogous for those tested, the analysis at the single cell level revealed that HFIF stimulation increases the number of NK active cells and target binding cells among normals, but not in leukemic patients.

SPET monitoring of auditory cortex activation by electric stimulation in a patient with auditory brainstem implant

Abstract Auditory cortex activation following multifrequency acoustic stimulation has been evaluated by means of single photon emission tomography (SPET) in one patient before and after an auditory brainstem implant (ABI). No activation could be observed after acoustic stimulation before ABI. After ABI stimulation in the coronal and axial slices, the activation within the temporal cortex contralateral to the stimulated ear was twice (43.76%) that of normal controls (23.94 ± 2.74%). This marked difference was not present in other selected cortical auditory areas (homolateral temporal, homolateral and contralateral parietal cortices). The temporal cortex was also examined with six consecutive sagittal slices from 18.75 mm up to 56.25 mm lateral to the midline. A very strong activation (51.20%) compared with that of normal controls (9.94 ± 7.45%) was detected in the 25.26-mm sagittal slice of the temporal cortex contralateral to ¶the stimulated side. The remaining sagittal slices showed ¶an almost normal post-stimulatory activation. As the 25.26-mm sagittal slice corresponds to the medial part of the auditory temporal cortex, its activation suggests that electrode stimulation is concentrated on the region of the cochlear nucleus in which the neurons that transduce high frequencies are located. SPET can be considered useful, in combination with electric auditory-evoked potentials, to obtain information on ABI placement and function, effectiveness of acoustic stimulation, degree of cortical stimulation and tonotopic spatial distribution of auditory cortex activation.

Combination of Cytosine-Arabinoside (ARA-C), Cyclophosphamide and Prednisone in the Treatment of B-Chronic Lymphocytic Leukemia in Advanced Stages and Progressive Disease

Recently the major advances in B-chronic lymphocytic leukemia (B-CLL) have been in defining biological characteristics and prognostic criteria. However it remains to be established which is the best therapeutic approach following the first line treatment, particularly when the patients are completely unresponsive to the standard treatment using Chlorambucil (CHL) and Prednisone (PDN) and the disease is progressive. We report the results of a combination regimen using Cytosine-Arabinoside (ARA-C), Cyclophosphamide (CTX) and PDN in 19 B-CLL patients with advanced disease, resistant to CHL + PDN. The treatment schedules were as follows: Schedule A) ARA-C 60mg/sqm from day 1 to 4 s.c., CTX 75 mg/sqm from day 1 to 4 i.v., PDN 40 mg/sqm from day 1 to 4 p.o.: courses were repeated every 4 weeks for 6 months; Schedule B) ARA-C 100 mg/sqm from day 1 to 7 s.c., CTX 100 mg/sqm from day 8 to 14 i.v., PDN 40 mg/sqm from day 1 to 21 p.o.: courses were repeated every 4 weeks for 6 months. Fourteen pts were treated with schedule A and 5 pts with schedule B. We observed 9 partial remissions (PR), 5 cases with no response and 5 patients with progression. The median duration of PR is 20 months and two patients remain in PR after 18 and 60 months, respectively. The combination of ARA-C, CTX plus PDN is highly effective in advanced stages and in pretreated B-CLL but we need larger randomized studies to draw more definitive conclusions.

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.