Long-lasting fever of unknown origin preceding the diagnosis of intravascular lymphomatosis: a further case stimulates some remarks

Neurological and skin involvements usually dominate the clinical presentation of intravascular lymphomatosis (IL), while fever is the most frequent general sign. However, an onset only characterized by fever of unknown origin (FUO) has been rarely reported. We would like to describe a further case of IL, which presented a long-lasting FUO before the diagnosis. At admission, physical examination detected hepatosplenomegaly without lymph nodes enlargement or dermatological or neurological abnormalities. Significant laboratory data included severe anemia, leukopenia, thrombocytopenia, and increased serum LDH. Moreover, a chest CT evidenced bilateral multiple pulmonary infiltrates and pleural effusion. After the development of proteinuria, a diagnosis of large B-cell intravascular lymphoma was made with a renal biopsy 10 months after the onset of the clinical manifestations. So far, more than 100 cases of IL have been reported and the diagnosis often turned out to be difficult, as clinical signs did not point to a lymphoproliferative disorder. This report confirms that FUO is not only frequently associated with IL but that it even marks the real onset of the disease. We are then tempted to conclude that undiagnosed fever is not so rare in IL and if we call it FUO, it is only because diagnosis is necessarily elusive and hence time-consuming. Am. J. Hematol

High frequency of the TCRBV20S1 null allele in the Sardinian population

Single nucleotide polymorphisms (SNPs) in the T-cell receptor (TCR) gene segments might play a role in shaping the TCR repertoire. Three polymorphisms have been described for the TCRBV20S1 gene segment, one of which is responsible for a nucleotide substitution at position 524, resulting in the introduction of a stop codon. Individuals homozygous for this inactivating polymorphism ("null allele") are unable to express TCRBV20 gene products. Using DNA restriction digestion analysis, we investigated the frequency of this polymorphism in 111 healthy Sardinian subjects. Inhabitants of the Mediterranean island of Sardinia are considered to represent a genetically isolated population. Our analyses revealed an incidence of 19.8% of homozygosity for the null allele, corresponding to an allele frequency of 0.45. Such an incidence, significantly higher than the one detected in 83 non-Sardinian Caucasians (6%), is the most elevated so far reported in the literature. BV20 is a single member subfamily and the null allele produces a gap in the potential TCR repertoire. Therefore, it is possible that an undetermined selective pressure could have played a role in determining the high frequency of this inactivating polymorphism in Sardinians. Alternatively, this finding could be related to a founder effect in this ancient island population

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

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

Patients with myelodysplastic syndromes show reduced frequencies of CD4⁺ CD8⁺ double-positive T cells

Even though the expression of CD4 and CD8 on thymocytes is considered mutually exclusive, CD4+ CD8+ double-positive T cells (DP) represent a small subset of T lymphocytes that have been described in the peripheral blood of normal individuals, as well as in some pathological conditions. In particular, an agedependent accumulation of monoclonal DP has been shown in elderly healthy subjects. From the functional point of view, DP are able to act as differentiated effector memory cells with specific antiviral functions

Efficacy of rituximab in autoimmune hemolytic anemia associated with splenic marginal zone lymphoma

Autoimmune manifestations including autoimmune hemolytic anemia (AIHA) are often described in association with splenic marginal zone lymphoma (SMZL) [1]. Moreover, AIHA has been recently reported as a potential risk factor of poor outcome for SMZL patients [2]. Among the different available therapeutic options, rituximab monotherapy has been recently shown to be extremely effective in SMZL [3]. On the other hand, this monoclonal antibody plays a key role in the treatment of steroid-refractory AIHA [4]. More specifically, although rituximab has been recently included among the possible strategies to treat AIHA secondary to chronic lymphocytic leukemia [5], very few cases describing its use in the course of SMZL-related AIHA have been described so far [6]

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 β-variable (βV) 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 βVs 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-βV 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

Derangement of the T-cell repertoire in patients with B-cell non-Hodgkin's lymphoma

Although a number of studies suggest that different immune pathways may play a role in the pathogenesis of non-Hodgkin's lymphomas (NHL), the shape of the T-cell compartment has been only superficially explored in these patients. In our study, we analyzed the peripheral T-cell receptor (TCR) repertoire and the distribution of different T-cell subsets – including regulatory T cells (Treg) – in 30 patients with NHL, by combining flow cytometry and spectratyping. We first demonstrated by flow cytometry an increased frequency of expanded T-cell subpopulations expressing the same TCR beta variable (BV) subfamilies in CD8+ cells from NHL patients when compared with healthy controls, beside a higher frequency of Treg. Moreover, NHL patients were characterized by a higher percentage of BVs showing a skewed CDR3 profile both in CD4+ and CD8+ cells when analyzed by spectratyping. Our data suggest that the T-cell branch of the immune system of patients with B-cell NHL is deeply deranged, as witnessed by the increased degree of activation and skewing of their TCR repertoire along with the higher frequency of Treg