In vitro production of anti-RBC antibodies and cytokines in chronic lymphocytic leukemia.

B-chronic lymphocytic leukemia (B-CLL) patients have a high prevalence of autoimmune phenomena, mainly autoimmune hemolytic anemia (AIHA). Immunoregulatory cytokines play a role in the regulation of both autoimmunity and leukemic B-cell growth. Mitogen-stimulated direct antiglobulin test (MS-DAT) is a recently described test able to disclose latent anti-RBC autoimmunity in AIHA. We investigated the prevalence of anti-RBC autoimmunity by MS-DAT and the pattern of cytokine production by PHA-stimulated whole blood cultures from 69 B-CLL patients and 53 controls. Results showed that anti-RBC IgG values in unstimulated, PHA-, PMA-, and PWM-stimulated cultures were significantly higher in B-CLL patients compared with controls. In B-CLL, the prevalence of anti-RBC autoimmunity was 28.9% by MS-DAT, compared with 4.3% by the standard DAT. Production of IFN-gamma, IL-2, IL-13, TNF-alpha, sCD23, and sCD30 was significantly increased in all B-CLL patients compared with controls, whereas there was no difference in IL-4, IL-6, IL-10, and TGF-beta production. Multivariate analysis showed that IL-4 was significantly increased in MS-DAT-positive compared with -negative patients. Patients with autoantibody positivity displayed greater IFN-gamma production than negative patients. These data are in line with the hypothesis that autoimmune phenomena in B-CLL are associated with an imbalance towards a Th-2-like profile. The elevated prevalence of anti-RBC autoimmunity found by MS-DAT suggests that an underestimated latent autoimmunity exists in B-CLL.

Early cutaneous lesions secondary to hydroxyurea therapy.

Hydroxyurea is a usually well-tolerated cytostatic agent, but its side effects include cutaneous lesions that appear after several years of maintenance therapy with hydroxyurea. The reported incidence of such adverse reactions varies from 10 to 35%; in our Center it is 2%. We describe a patient with essential thrombocythemia who presented with ulcers of the hands only 15 days after hydroxyurea treatment.

In vitro effects of IL-2 on NK-activity, clonogenic potential, blast cell proliferation and cytokine release of MDS bone marrow patients.

To evaluate the clinical usefulness of IL-2 in myelodysplastic syndromes (MDS) the in vitro effects of interleukin-2 (IL-2) on blast cell proliferation, clonogenic activity, cytokine release and cell mediated cytotoxicity were examined in 49 MDS patients. Morphological analyses of bone marrow (BM) cytospin preparations showed a significant decrease in the number of blast cells in MDS after incubation with IL-2. Incubation of bone marrow mononuclear cells (BMMNCs) with IL-2 induced a significant increase in the number of CFU-GM in comparison with untreated controls. gamma-IFN and GM-CSF, but not alpha-TNF were found to be released in significant amounts by the BMMNCs cultured with IL-2. No significant differences in the surface phenotypes of fresh lymphocytes were observed between the normal and MDS subjects. After incubation with IL-2, we observed a significant increase in the number of CD3-/CD56+ cells in both normal and MDS subjects. Peripheral blood (PB) and BM NK activity against K562 was significantly greater in MDS after stimulation with IL-2. These data suggest the clinical usefulness of IL-2 in a large subgroup of patients as it may reduce the percentage of blasts and increase clonogenic capacity and cell-mediated cytotoxicity.

Analysis of p53 gene mutations in acute myeloid leukemia.

We have previously reported the absence of mutations within exons 5-9 of the p53 gene in a panel of 30 cases of acute promyelocytic leukemia (APL), which represent the M3 FAB type of acute myeloid leukemia (AML). In the present report, we extend our analysis of p53 gene mutations to 70 cases of AML representative of the other FAB types of the disease, including M1 (16 cases), M2 (20 cases), M4 (17 cases), M5 (12 cases), and M6 (5 cases). DNAs were analyzed for p53 gene mutations in exons 5 to 9 by polymerase chain reaction (PCR), single-strand conformation polymorphism (SSCP), and direct sequencing of PCR-amplified products. Mutant p53 alleles were detected in 5 of 70 cases; 1 case in exon 5, 2 cases in exon 6, and 2 cases in exon 7. The alterations of the p53 gene were represented by point mutation leading to an amino acid substitution in four cases, and deletion in the remaining case. In four of the five cases, direct sequencing indicated the loss of the normal p53 allele; in the remaining case, two mutations were detected, presumably involving both p53 alleles. Three cases showed mutations at diagnosis; in the remaining two, the mutations were observed in clinical relapse but not at diagnosis. Our results confirm the relatively low incidence of p53 mutations in AML and further support the evidence that p53 plays a role in leukemogenesis through a recessive mechanism (two-hit model) of inactivation of tumor suppressor activity.

Analysis of alterations of oncogenes and tumor suppressor genes in chronic lymphocytic leukemia.

B cell chronic lymphocytic leukemia (B-CLL) represents the most frequent adult leukemia in the Western world. The molecular pathogenesis of B-CLL is largely unknown. Although initial reports on small panels of cases had suggested a role for Bcl-1 and Bcl-2 oncogene activation in B-CLL, later investigations failed to confirm these data. Among tumor suppressor genes, p53 mutations have been reported in a fraction of cases. In this study, we have attempted a conclusive definition of the involvement of dominantly acting oncogenes (Bcl-1 and Bcl-2) and tumor suppressor loci (p53, 6q-) in 100 cases of B-CLL selected for their CD5 positivity and Rai's stage (0 to IV). Rearrangements of Bcl-1 and Bcl-2 and deletions of 6q and 17p were analyzed by Southern blot using multiple probes. Mutational analysis (single strand conformation polymorphism and polymerase chain reaction direct sequencing) was used to assay p53 inactivation. No alterations of Bcl-1 or Bcl-2 were detected in the 100 cases tested. Mutations of p53 were found in 10/100 cases without any significant association with clinical stage. Deletions of 6q were present in 4/100 cases. Overall, our data indicate that: 1) contrary to previous reports, Bcl-1 and Bcl-2 rearrangements are not involved in CD5+ B-CLL pathogenesis and 2) p53 mutations are present in 10% of cases at all stages of the disease.

CD34 immunohistochemistry of bone marrow biopsies: prognostic significance in primary myelodysplastic syndromes.

Bone marrow (BM) biopsies from 58 patients with primary myelodysplastic syndrome (MDS) were studied using QBEND10, a monoclonal antibody that recognizes the human progenitor CD34 antigen in routine aldehyde-fixed paraffin-embedded samples. FAB subtypes were RA (5 patients), RARS (9 patients), RAEB (20 patients), RAEBt (11 patients), CMML (3 patients). In addition, 10 MDS patients whose BM biopsies revealed heavy reticulum fibrosis were included. Neither the percentage of CD34+ cells nor the number of CD34+ aggregates (defined as clusters of 3 or more cells) correlated with the presence and morphology of abnormal localizations of immature precursors (ALIP). When all patients were considered, median survival was 69 months in those with less, and 25 months in patients with more than 1% CD34+ cells (P < 0.05). Median survival was 15 months in patients with CD34+ aggregates and 41 months in those without aggregates (P = 0.0017). When RAEB patients were considered median survival was 41 months in those with less than 1%, and 29 months in those with more than 1% CD34+ cells; the 4-year survival chance was 45% in the former and 18.3% in the latter group. Therefore, CD34 positivity of more than 1% identifies a subset of RAEB patients with shorter life expectancy. In addition, leukemic transformation was observed in 11 of 35 patients (31%) with no CD34 aggregates, but in 14 of 23 patients (60%) with aggregates (P < 0.05). CD34 immunostaining, which can be easily performed on routinely prepared BM biopsies, was found to be a powerful prognostic tool for predicting survival and outcome in MDS.

Differential expression of very late activation antigen-3 (VLA-3)/VLA-4 in B-cell non-Hodgkin lymphoma and B-cell chronic lymphocytic leukemia.

The expression of beta 1 (very late activation antigens, VLA 1-6) and beta 2 integrins (leukocyte adhesion molecules [Leu-CAM]) in cell suspensions from the peripheral blood of 70 patients with B-cell chronic lymphocytic leukemia (B-CLL), 15 patients with leukemic lymphocytic lymphoma of intermediate differentiation (IDL), as well as from the lymph nodes of 20 patients with low/intermediate-grade non-Hodgkin's lymphoma (NHL) was studied with the aim of characterizing their adhesive phenotype and evaluating its relationship to clinical behavior. CD11a(LFA-1) was more expressed in NHL and IDL than in B-CLL (P = .047), although it was demonstrable in 74.2% of cases; CD11c was more expressed in B-CLL (P less than .0001), and its expression was preserved in almost all of the cases of small lymphocytic lymphoma. In NHL patients, including the cases of IDL, VLA-3 expression was observable in 8 of 35 cases (although always at a low level of intensity), while VLA-4 was almost constantly expressed in a way that was similar to its expression in control normal B cells. On the contrary, in B-CLL patients, VLA-3 was expressed (prevalently at high levels) in 87.1% of cases and VLA-4 only in 37.1%. No correlation was found between adhesion molecule patterns and the clinical features of the diseases. The biofunctional significance of the imbalance of VLA-3 and VLA-4 expression in B-CLL is not easy to explain, but it has undoubted intrinsic value as an additional marker for distinguishing B-CLL from, in particular, those B-cell neoplasms (such as IDL) that share many of the immunocytomorphologic characteristics and the putative normal counterpart (the mantle zone) of B-CLL.

Immunophenotypes in "classical" B-cell chronic lymphocytic leukemia. Correlation with normal cellular counterpart and clinical findings.

This study evaluates the expression of a series of membrane antigens, normally expressed by B-lymphocytes of the lymphocytic mantle and marginal zone, in 90 selected cases of "classical" (mouse red blood cell-receptor+, CD20+, CD5+, surface immunoglobulin +/-) B-chronic lymphocytic leukemia (B-CLL) with the aim of contributing toward identifying the normal counterpart of B-CLL and any correlations between surface antigen pattern and certain clinical characteristics. Clustered (CD23, 25, 39, 40, 27, 1c, w75) and unclustered (NuB1, 7F7, KiB3) monoclonal antibodies (MoAb) were tested. Almost all cases showed high reactivity to CD23, 27, w75, 39, 40, and NuB1: expression of CD1c was very low and that of 7F7, KiB3, and CD25 was variable. The reactivity of 7F7 and KiB3 was strictly correlated, and they correlated individually with CD25. Results show that the most frequent B-CLL phenotype (CD19+, 5+, 23+, 27+, 39+, NuB1+, KiB3 +/-, 7F7 +/-, and CD25 +/-) corresponds to one or more cellular subsets in the mantle zone. No correlation was found between MoAb expression, surface immunoglobulin (SIg) class or type, clinical stage, disease activity, or age at diagnosis. The only difference (statistically borderline) was the expression of 7F7 and KiB3 (in young versus old patients). This suggests that modulations in the expression of surface antigens do not affect the clinical behavior of the disease.

Recombinant gamma-interferon as first line therapy for high risk myelodysplastic syndromes. Italian MDS Study Group.

Thirty patients affected by previously untreated high risk myelodysplastic syndromes (MDS) were treated with human recombinant gamma-interferon (r-IFN-gamma): 15 of them with a higher dose (HD) of 0.1 mg/sqm, three times a week and 15 with a lower dose (LD) of 0.01 mg/sqm, three times a week, both doses administered subcutaneously (s.c.). The therapy was fairly well tolerated and few major toxic events were documented. Sustained improvement of one or more clinico-hematologic parameters was observed in 43.3% of the patients (26.6% and 60.0% for the lower and higher dose, respectively). Median survival time from the start of IFN-gamma therapy was 15+ months (range: 1-26) for patients with refractory anemia with excess of blasts (RAEB) versus 5 months (range 2-12) for patients with RAEB in transformation (RAEB-t); 15+ months (range 1-26) for HD patients versus 8 months (range 2-23) for patients treated with LD regimen; 16+ months (range 9-26) for responders versus 7 months (range 1-22) for nonresponders. All these three variables (diagnosis, treatment, and response to treatment) turned out to be statistically significant (p = at least less than 0.01) at Cox's analysis.

Plasma cyclic nucleotide levels in patients with refractory anaemia with excess of blasts.

To verify the clinical usefulness of extracellular cyclic nucleotide determinations as tumour markers in preneoplastic syndromes, plasma cyclic AMP (cAMP) and cyclic GMP (cGMP) levels were monitored in 47 patients with refractory anaemia with excess of blasts (35 RAEB and 12 RAEBt), 20 of whom progressed to acute leukaemia during the observation period. The control group consisted of 45 healthy subjects matched for age and sex. In all groups of patients plasma cAMP levels were within the normal range, whereas plasma cGMP levels were significantly higher than those of normal subjects in both RAEB and RAEBt patients, and increased further when progression to acute leukaemia occurred. These data suggest that serial determinations of plasma cGMP may be useful to monitor the progression of the disease, though there is no evidence that cGMP values at diagnosis may have a prognostic significance.