Maurizio Roberto Longinotti

Patients with myelodysplastic syndromes display several T-cell expansions, which are mostly polyclonal in the CD4+ subset and oligoclonal in the CD8+ subset

OBJECTIVE Immune dysregulation plays a role in the pathophysiology of myelodysplastic syndromes (MDS), as T-cell clones seem to be involved in the inhibition of hematopoietic precursors. The purpose of this study was to analyze the T-cell receptor (TCR) repertoire of MDS patients, focusing on the third complementarity determining region (CDR3) pattern of their CD4(+) and CD8(+) lymphocyte expansions. MATERIALS AND METHODS The study involved 30 patients and 15 age-matched controls. The beta-variable (betaV) subfamily flow-cytometry analysis was performed on peripheral CD4(+) and CD8(+) T-cells. Spectratyping TCR-CDR3 analysis was carried out on isolated helper and cytotoxic T lymphocytes after immunomagnetic separation and reverse-transcriptase polymerase chain reaction. RESULTS We first identified by flow cytometry an increased frequency of expanded betaVs in both CD4(+) and CD8(+) T-cells in MDS patients. We then showed, by spectratyping, that the CDR3 profile was mostly Gaussian in their CD4(+) T cells, whereas CD8(+) T cells usually showed skewed or oligoclonal CDR3 regions. When we compared spectratyping and flow-cytometry findings in each patient, we showed that most CD4(+) lymphocyte expansions detected by flow cytometry had Gaussian CDR3 profiles, whereas most CD8(+) expansions were oligoclonal. CONCLUSION We confirm that in MDS patients the TCR-betaV repertoire is overall extremely contracted, especially in cytotoxic T cells. This pattern is mainly determined by selective proliferations of both helper and cytotoxic T cells, which are, however, mostly polyclonal in the former and oligoclonal in the latter. Such a difference, possibly related to the different human leukocyte antigen restriction, could reflect the selective involvement of cytotoxic T cells either in the anti-tumor immune surveillance or in an autoreactive aggression toward hematopoietic precursors.

Cytogenetic and hematological spontaneous remission in a case of acute myelogenous leukemia

Abstract:  Several cases of spontaneous remission (SR) interrupting the invariably progressive course of untreated acute myeloblastic leukemia (AML) have been reported so far. We shall add to this series the hematological and cytogenetic SR occurring in a 72‐yr‐old man affected by AML following myelodysplastic syndrome. At diagnosis cytogenetic analysis showed the 48, xy, del (6) (p22‐pter), +13, +14 karyotype. Owing to a lobar pneumonia, the chemotherapy was deferred and a broad spectrum antibiotic therapy was established. Supportive care included red cells and platelet transfusions and low‐dose corticosteroid. Two months later, after the pneumonia had completely disappeared, a complete remission, lasting about 5 months, was documented on bone marrow morphological and cytogenetical examination, although some degree of myeloid dysplasia persisted. Possible mechanisms of the various SRs described during the course of AML are discussed with a review of the literature.

Follicular spicules and multiple ulcers: cutaneous manifestations of multiple myeloma

We describe 2 patients with multiple myeloma who had horn-like filiform spicules in the follicular orifices of the face, particularly on the nowe, and multiple small ulcerations on the trunk. In the first patient, histopathologic study of a specimen from the nose showed follicular plugs of compact homogeneous eosinophilic material filling the intercellular spaces surrounding the keratinocytes. The same eosinophilic deposits were seen in the ulcer. In the second patient, biochemical investigation revealed that skin matter from spicules and ulcers were made up of monoclonal dysprotein with electrophoretic characteristics identical to those found in patient serum.

Serum erythropoietin levels in thalassemia intermedia

SummarySerum concentrations of erythropoietin (EPO) were determined by immunoassay in 45 patients with thalassemia intermedia (TI). The mean serum level of EPO was significantly higher in the thalassemic patients than in the controls, but transfused subjects had lower pretransfusional serum concentrations of EPO than untransfused ones. An inverse relationship between the serum values of EPO and total hemoglobin was observed only in the untransfused thalassemic patients. These data suggest that in TI, even a low transfusional regimen may cause a decrease in serum concentration of EPO, independent of the level of total Hb.

The role of T-cells in the pathogenesis of myelodysplastic syndromes: Passengers and drivers

Although a burden of clinical and experimental data suggest the involvement of T-lymphocytes in the pathogenesis of myelodysplastic syndromes (MDS), the actual weight exerted by T-cells in this scenario is yet to be conclusively dissected. This brief review will try to further address this point, by running through the most relevant studies exploring the T-cell repertoire of MDS patients as well as the potential role of specific T-cell subsets such as regulatory T-cells and Th17 T-cells.

Somatic deletion of the normal beta-globin gene leading to thalassaemia intermedia in heterozygous beta-thalassaemic patients.

Two β‐thalassaemia patients, whose constitutive genotype was β39C/β39C→T, had the clinical phenotype β‐thalassaemia intermedia. Analysis of leucocyte DNA showed the presence of the mutated β39C→T‐gene exclusively, while the normal β39C‐gene was also present in reticulocyte RNA. Deletional analysis of chromosome 11p15.5 on leucocyte DNA showed large deletions including the β‐globin gene. Two populations of erythroid progenitors, one heterozygous and the other hemizygous for the β39C→T mutation, were demonstrated in one case. This confirms that, in heterozygous individuals, β‐thalassaemia intermedia may be caused by inactivation of the β‐locus in trans as a result of chromosome 11p15.5 deletions in a subpopulation of haematopoietic cells.

Are T-cell dysfunctions the other side of the moon in the pathogenesis of myelodysplastic syndromes?

Even though the pathogenesis of myelodysplastic syndromes (MDS) is dominated by an inefficient maturation of haematopoietic precursors, also immune mechanisms seem to play a crucial functional role. In this review, we will first describe the clinical and laboratory autoimmune manifestations often detectable in MDS patients. We will then focus on studies addressing the mechanisms of T‐cell activation and their implications in the disease history. The potential impact of specific cell subsets, such as regulatory T‐cells, Th17 cells and natural killer cells, will be also described. We will finally focus on potential therapeutic approaches based on immunomodulation, ranging from more classical immunosuppressive drugs to vaccination and transplantation strategies.

Patients with Early-Stage Myelodysplastic Syndromes Show Increased Frequency of CD4+CD25high+CD127low Regulatory T Cells

Regulatory T cells (Treg) have often been ascribed a role in the pathophysiology of several neoplastic diseases considering their potential ability to suppress anti-tumor immunity. This is particularly the case in myelodysplastic syndromes (MDS), which are clonal hematologic disorders characterized by marked immune dysregulation. We analyzed Treg frequencies in a cohort of 36 patients with early-stage MDS using a flow-cytometric approach based on the concomitant expression of CD25 and CD127. MDS patients showed a higher frequency of CD4+CD25high+CD127low Treg than healthy controls (1.51 vs. 1.14%), with no specific effect of patient- and disease-related factors. Our data point to impaired anti-tumor immunity in patients with MDS, even in the early stage, which has already been noted in other clonal disorders.

A case of coexistence between JAK2V617F and BCR /ABL.

Very recently the JAK2V617F mutation has been described in BCR⁄ABL+ patients for the first time. Even though characterized by very different clinical patterns, these cases raise some questions about the biological meaning of the coexistence between these disease-specific molecular markers. The present report confirms that the unexpected coexistence between these two disease-specific molecular markers - the JAK2V617F mutation and the BCR⁄ABL translocation - is possible.

Azacitidine improves the T-cell repertoire in patients with myelodysplastic syndromes and acute myeloid leukemia with multilineage dysplasia

Patients with myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML) with multilineage dysplasia show several immunological abnormalities. In this clinical setting, by combining flow cytometry and CDR3 spectratyping we monitored the kinetic of the T-cell repertoire during Azacitidine treatment, in order to explore its potential ability to reverse the immune derangement typical of these disorders. We firstly demonstrated by flow cytometry an increase in both CD4+ and CD8+ T-cell frequencies after starting treatment. Moreover, when monitored by spectratyping our patients showed significant changes in their T-cell receptor (TCR) CDR3 profiles, which were much more evident in helper T-cells. In fact, the frequency of BV (beta variable) subfamilies showing a skewed CDR3 profile significantly decreased from baseline to the following evaluations in CD4+ T-cells (81% vs. 70%). This pattern was even more pronounced in patients responding to Azacitidine (90% vs. 61%). Our data show that the overall derangement of the T-cell repertoire detectable in patients with MDS and AML with multilineage dysplasia gradually improves during Azacitidine treatment. These findings therefore suggest that Azacitidine could be potentially able, not only to restore the hematopoietic function, but also to reverse the immune derangement typical of these hematologic disorders.