Persistent polyclonal B lymphocytosis with binucleated lymphocytes: a study of 25 cases. Groupe Français d'Hématologie Cellulaire

Cytogenetics in the management of clonal chromosomal abnormalities of undetermined significance and persistent polyclonal B-cell lymphocytosis: Guidelines from the Groupe Francophone de Cytogénétique Hématologique (GFCH)

Acquired clonal chromosomal abnormalities (CAs) are usually considered to be disease-related. However, when a CA of this type is the only abnormality present (and especially in small clones), the clinical significance is unclear. Here, we review the literature on recurrent CAs whose significance is regularly subject to debate. Our objective was to help with their interpretation and develop guidelines for sex chromosome loss, trisomy 15, trisomy 8, deletion 20q and other isolated non-myelodysplastic neoplasm (MDS)-defining CAs. We suggest that non-MDS-defining CAs correspond to clonal hematopoiesis of indeterminate potential (CHIP) in the absence of cytopenia and clonal cytopenia of undetermined significance (CCUS) in the presence of cytopenia. Lastly, we review the literature on persistent polyclonal binucleated B-cell lymphocytosis; although usually benign, this condition may correspond to a premalignant state.

Somatic Sex: On the Origin of Neoplasms With Chromosome Counts in Uneven Ploidy Ranges

Stable aneuploid genomes with nonrandom numerical changes in uneven ploidy ranges define distinct subsets of hematologic malignancies and solid tumors. The idea put forward herein suggests that they emerge from interactions between diploid mitotic and G0/G1 cells, which can in a single step produce all combinations of mono-, di-, tri-, tetra- and pentasomic paternal/maternal homologue configurations that define such genomes. A nanotube-mediated influx of interphase cell cytoplasm into mitotic cells would thus be responsible for the critical nondisjunction and segregation errors by physically impeding the proper formation of the cell division machinery, whereas only a complete cell fusion can simultaneously generate pentasomies, uniparental trisomies as well as biclonal hypo- and hyperdiploid cell populations. The term "somatic sex" was devised to accentuate the similarities between germ cell and somatic cell fusions. A somatic cell fusion, in particular, recapitulates many processes that are also instrumental in the formation of an abnormal zygote that involves a diploid oocyte and a haploid sperm, which then may further develop into a digynic triploid embryo. Despite their somehow deceptive differences and consequences, the resemblance of these two routes may go far beyond of what has hitherto been appreciated. Based on the arguments put forward herein, I propose that embryonic malignancies of mesenchymal origin with these particular types of aneuploidies can thus be viewed as the kind of flawed somatic equivalent of a digynic triploid embryo.

Patients with Persistent Polyclonal B-Cell Lymphocytosis Share the Symptomatic Criteria of Systemic Exertion Intolerance Disease

Introduction: Persistent polyclonal B-cell lymphocytosis (PPBL) is a rare and still poorly understood entity, with 90% of cases occurring in female smokers. Patients often appear tired and in pain, but the clinical symptoms remain imprecise. The main risk is the development of lymphoma in some cases. To better understand the characteristics of the fatigue associated with PPBL and study its relationship with systemic exertion intolerance disease (SEID), we analyzed the symptoms in a cohort of patients with PPBL included in the French national registry. Material and methods: An anonymous questionnaire following the recommendations of the Institute of Medicine/National Academy of Medicine for screening of the new SEID criteria was created in French and mailed to 50 patients. Results: Thirty-nine (78%) contacted patients responded. The studied population was mainly constituted of women (90%) with an average age of 50 (18–59) years. Smoking was a constant factor in all patients. A total of 28/39 (72%) respondents met the SEID symptoms criteria. Severe chronic fatigue for more than 6 months was noted in 36/39 cases (92%). Unrefreshing sleep, post-exertional malaise, cognitive impairment, and orthostatic intolerance were described in 30/39 (77%), 32/39 (82%), 28/39 (72%), and 27/39 (69%) cases, respectively. Pain (arthralgia, myalgia, headache) was present in 26/39 (67%) cases. The most prominent SEID symptoms were fatigue, followed by post-exercise discomfort and cognitive difficulties. The most disabling symptom was non-restorative sleep, followed by pain. An inflammatory and/or autoimmune context was noted in 13 patients (33%), and these comorbidities could have favored the deterioration of the general condition. Three patients also presented with fibromyalgia. However, 3 patients did not mention any complaints. Conclusion: This survey indicated that patients with PPBL most often initially presented with disabling chronic fatigue, chronic pain, and other symptoms suggestive of SEID but requiring more studies to confirm it. Education of medical staff about the symptoms of PPBL should be encouraged to better assess this peculiar condition.

Hairy B-Cell Lymphoproliferative Disorder and its Differential Diagnosis: a Case with Long-Term Follow-Up

Hairy B-cell lymphoproliferative disorder (HBLD) is one of chronic polyclonal B-cell lymphocytosis. We report a 47-year-old female Japanese patient diagnosed as having HBLD based on lymphocytosis with hairy cell appearance and characteristic phenotypes including CD11c+ and without B-cell monoclonality. She was a non-smoker and possessed HLA-DR4. She has been closely followed up without treatment and lymphoma development for over five years. Although this disease is quite rare and has been reported, to our knowledge, in only 13 Japanese cases, an accurate diagnosis, particularly differential diagnosis from persistent polyclonal B-cell lymphocytosis or hairy cell leukemia-Japanese variant is essential for the prevention of unnecessary treatments.

B-cell signaling in persistent polyclonal B lymphocytosis (PPBL)

Persistent polyclonal B lymphocytosis (PPBL) is a benign hematological disorder characterized by a selective expansion of circulating polyclonal marginal zone (MZ)-like B cells. Previous reports demonstrated that cases of PPBL showed poor activation, proliferation and survival of B cells in vitro, yet the underlying defect remains unknown. Here we report for the first time an attenuated activation of the canonical NF-κB (nuclear factor of kappa light polypeptide gene enhancer in B cells) and mitogen-activated protein kinase/extracellular signal-regulated kinase pathway after CD40 stimulation. This defect was selective, as alternative NF-κB signaling after CD40 stimulation and both B-cell receptor- and Toll-like receptor 9-mediated activation remained unaffected. Reduced canonical NF-κB activation resulted in decreased IκBα and CD40 expression in resting cells. In PPBL patients, expression of Bcl-xL in MZ-like B cells did not increase upon activation, consistent with the high apoptosis rates of PPBL-derived B cells that were observed in vitro. The B-cell phenotype of mice with selective knockouts of early components of the CD40 signaling pathway resembles PPBL, but sequencing corresponding genes in sorted MZ-like B cells of PPBL patients did not reveal relevant genetic alterations. Nevertheless, the frequently observed mutations in early signaling components of the NF-κB pathway in MZ lymphomas underline the relevance of our findings for the pathogenesis of PPBL.

Persistent polyclonal binucleated B-cell lymphocytosis and MECOM gene amplification

Background

Persistent Polyclonal Binucleated B-cell Lymphocytosis (PPBL) is characterized by a chronic polyclonal B-cell lymphocytosis with binucleated lymphocytes and a polyclonal increase in serum immunoglobulin-M. Cytogenetic is characterized by the presence of a supernumerary isochromosome +i(3)(q10), premature chromosome condensation and chromosomal instability. Outcome of PPBL patients is mostly benign, but subsequent malignancies could occur. The aim of our study is to provide an update of clinical and cytogenetic characteristics of our large cohort of PPBL patients, to describe subsequent malignancies occurring during the follow-up, and to investigate the role of the long arm of chromosome 3 in PPBL.

Results

We analyzed clinical, biological and cytogenetic characteristics (conventional cytogenetic analysis and fluorescent in situ hybridization) of 150 patients diagnosed with PPBL. We performed high-resolution SNP arrays in 10 PPBL patients, comparing CD19⁺ versus CD19⁻ lymphoid cells. We describe the cytogenetic characteristics in 150 PPBL patients consisting in the presence of supernumerary isochromosome +i(3)(q10) (59 %) and chromosomal instability (55 %). In CD19⁺ B-cells, we observed recurrent copy number aberrations of 143 genes with 129 gains (90 %) on 3q and a common minimal amplified genomic region in the MECOM gene. After a median follow-up of 60 months, we observed the occurrence of 12 subsequent malignancies (12 %), 6 solid tumors and 6 Non-Hodgkin’s Lymphomas, and 6 monoclonal gammopathies of undetermined significance (MGUS), requiring a long-term clinical follow-up.

Conclusions

Our clinical and cytogenetic observations lead us to hypothesize that isochromosome 3q, especially MECOM abnormality, could play a key role in PPBL.

Persistent Polyclonal B Cell Lymphocytosis B Cells Can Be Activated through CD40-CD154 Interaction

Persistent polyclonal B cell lymphocytosis (PPBL) is a rare disorder, diagnosed primarily in adult female smokers and characterized by an expansion of CD19⁺CD27⁺IgM⁺ memory B cells, by the presence of binucleated lymphocytes, and by a moderate elevation of serum IgM. The clinical course is usually benign, but it is not known whether or not PPBL might be part of a process leading to the emergence of a malignant proliferative disorder. In this study we sought to investigate the functional response of B cells from patients with PPBL by use of an optimal memory B cell culture model based on the CD40-CD154 interaction. We found that the proliferation of PPBL B cells was almost as important as that of B cells from normal controls, resulting in high immunoglobulin secretion with in vitro isotypic switching. We conclude that the CD40-CD154 activation pathway is functional in the memory B cell population of PPBL patients, suggesting that the disorder may be due to either a dysfunction of other cells in the microenvironment or a possible defect in another B cell activation pathway.

Performance evaluation and relevance of the CellaVision DM96 system in routine analysis and in patients with malignant hematological diseases

The CellaVision™ DM96 is an automated image analysis system dedicated to locating and preclassifying the various types of white blood cells in peripheral blood smears. The system also partially characterizes of the red blood cell morphology and is able to perform platelet counts. We routinely analyzed the blood samples from 440 patients with quantitative and/or qualitative abnormalities detected by the XE-2100 Sysmex™. Only 2.6% of cells are not identified by DM96™. After classification of the unidentified cells very good correlation coefficients are observed between DM96™ and manual microscopy for most hematological parameters and accuracy is judged excellent up to 98%. For most common parameters, false positive and false negative ratios are also very good. Whatever the pathology and the number of blasts on smear, all patients were positive for blast detection on DM96™. The system is a useful tool for assisting in the diagnosis and classification of most acute or chronic leukemia. Automatic cell location and preclassification, along with unique cell views on the computer screen, could reduce the time spent performing differentials and make real-time collaboration between colleagues a natural part of the classification process. The workstation also provides an ergonomically correct and relaxed working environment. We suggest its use in routine analysis; the system could be very helpful for the accurate morphological diagnosis of samples from patients with malignant hematological disease.

Polyclonal B-cell lymphocytosis with binucleated lymphocytes (PPBL)

Persistent polyclonal B-cell lymphocytosis (PPBL) is a rare and recently described entity. The review of the literature show PPBL is diagnosed predominantly but not exclusively in women, usually smokers. PPBL is recognized by a moderate, chronic and absolute lymphocytosis (>4 × 10(9)/l) in the peripheral blood. In 10% of cases without lymphocytosis, the PPBL diagnosis has to be suggested by peripheral blood examination showing in all cases atypical binucleated lymphocytes. A polyclonal serum IgM is also associated and HLA-DR7 expression is present in most cases. Contrary to B-cell chronic lymphoproliferative disorders (B-CLPD), peripheral B cells are polyclonal with kappa and lambda light-chain expression and no clonal rearrangement of immunoglobulin heavy chain genes is usually demonstrated. The detection of an extra isochromosome for the long arm of chromosome 3 +i(3)(q10) has to be considered as a specific marker of PPBL. We performed conventional cytogenetic analysis (CCA) in 111 patients with typical PPBL we followed-up more than 4 years. +i(3q) was detected in 34% (33/98), PCC in 8% (8/98) and both abnormalities in 31% (30/98). CCA showed neither +i(3q) nor PCC in 28% (27/98). Fluorescence in situ hybridization (FISH) was also performed in 84 cases and +i(3q) was detected in 71% (60/84). When combining both procedures in 84 patients, +i(3q) was detected in 17 patients with negative CCA and was confirmed in 43 patients with positive CCA. CCA and FISH were both negative in 24 cases. Whether patients with PPBL are at increased risk of hematological malignancy remains unclear. After a median follow-up of 4.4 years, most PPBL patients presented a stable clinical and biological course. Six patients died from pulmonary cancer, myocardial infarction, cerebral aneurysm rupture or diffuse large B-cell lymphoma. Two patients had IgM monoclonal gammopathy of undetermined significance (MGUS) at the time of PPBL diagnosis and two other patients developed IgM MGUS respectively 12 and 22 years after PPBL diagnosis. A malignant non Hodgkin's lymphoma (NHL) appeared in 3 additional patients: two patients presented diffuse large B cell lymphoma and 1 patient a splenic marginal zone lymphoma. In conclusion, the possibility of PPBL to evolve toward a clonal proliferation, malignant lymphoma or secondary solid cancer lead us to consider PPBL not as a benign pathology. We recommend a careful and continued clinical and biological long-term follow-up in all PPBL patients.

Combined automated cell and flow cytometric analysis enables recognition of persistent polyclonal B-cell lymphocytosis (PPBL), a study of 25 patients

Persistent polyclonal B-cell lymphocytosis (PPBL) is an extremely rare disorder, which occurs almost exclusively in smoking women and is characterized by a lymphocytosis with circulating binucleated lymphocytes. We analyzed 25 PPBL patients with respect to immunophenotype and by adaptive cluster analysis system (ACAS). Furthermore, HLA type, presence of Epstein-Barr virus (EBV) DNA in B cells, and clinical data were evaluated. Overall, the median percentages of B cells in PPBL patients with expression of CD5(dim), CD23(dim), CD25, CD27, and FMC7 were 21%, 38%, 16%, 74%, and 93%. Compared to normal controls, ACAS revealed a subset of nucleic-acid-rich lymphocytes located between the regular lymphocyte and regular monocyte region. Sixteen (64%) of 25 patients carried a HLA DR7 phenotype. Quantitative real-time polymerase chain reaction analysis did not detect relevant amounts of EBV DNA in circulating B cells of any patient. During a median follow-up of 5 years, a single patient developed lymphoplasmacytic lymphoma. The abnormal morphology and frequent, albeit dim, expression of CD5 and CD23 in PPBL may result in erratic diagnostic assignment of this benign disorder. However, incorporation of immunophenotyping and ACAS into the diagnostic algorithm allows recognition of PPBL in routine analysis and its differentiation from malignant B cell lymphoproliferative diseases. We found that an infection of a significant percentage of PPBL cells by EBV is unlikely. The observation of malignant lymphoma in a single patient implicates that evolution into a clonal malignant transformation may occasionally occur in PPBL.

Splenic marginal zone lymphoma proposals for a revision of diagnostic, staging and therapeutic criteria

Since the initial description of splenic marginal zone lymphoma (SMZL) in 1992, an increasing number of publications have dealt with multiple aspects of SMZL diagnosis, molecular pathogenesis and treatment. This process has identified multiple inconsistencies in the diagnostic criteria and lack of clear guidelines for the staging and treatment. The authors of this review have held several meetings and exchanged series of cases with the objective of agreeing on the main diagnostic, staging and therapeutic guidelines for patients with this condition. Specific working groups were created for diagnostic criteria, immunophenotype, staging and treatment. As results of this work, guidelines are proposed for diagnosis, differential diagnosis, staging, prognostic factors, treatment and response criteria. The guidelines proposed here are intended to contribute to the standardization of the diagnosis and treatment of these patients, and should facilitate the future development of clinical trials that could define more precisely predictive markers for histological progression or lack of response, and evaluate new drugs or treatments.

Pathology of chronic lymphocytic leukemia: an update

Chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL) is a clonal lymphoproliferative disorder characterized by proliferation of morphologically and immunophenotypically mature lymphocytes. CLL/SLL may proceed through different phases: an early phase in which tumor cells are predominantly small in size, with a low proliferation rate and prolonged cell survival, and a transformation phase with the frequent occurrence of extramedullary proliferation and an increase in large, immature cells. Although some patients with CLL have an indolent disease course and die after many years of unrelated causes, others have very rapidly disease progression and die of the disease within a few years of the diagnosis. In the past few years, considerable progress has been made in our ability to diagnose and classify CLL accurately. Through cytogenetics and molecular biology, it has been shown that CLL and variants are associated with a unique genotypic profile and that these genetic lesions often have a direct bearing on the pathogenesis and prognosis of the disease. Similarly, the development of antibodies to new biologic markers has allowed the identification of a unique immunophenotypic profile for CLL and variants. Moreover, accumulating evidence suggests that CLL cells respond to selected microenvironmental signals and that this confers a growth advantage and an extended survival to CLL cells. In this article, we will review the progress in the pathobiology of CLL and give an update on prognostic markers and tools in current pathology practice for risk stratification of CLL.

[Asymptomatic 32 year old female smoker with persistent polyclonal lymphocytosis]

A 32 year old female smoker (20 pack years) presented with an asymptomatic lymphocytosis of 13,000/nl and splenomegaly. The patient's blood smear showed an absolute lymphocytosis with 65% atypical lymphocytes. A total of 1% of the lymphocytes were bilobulated. Bone marrow histology and immunphenotyping of blood and bone marrow excluded leukemia and non-Hodgkin's lymphoma. IgH-CDR-3 PCR analysis revealed a polyclonal pattern. In summary, a persistent polyclonal B-cell-lymphocytosis (PPBL) was diagnosed. The exact etiology of PPBL is still unclear, however, it is associated with a polyclonal raise in the lymphocyte count of CD27+IgD+-memory-B-lymphocytes due to a defect in apoptosis signaling and leukocyte homing to secondary lymphoid tissues. An association with cigarette smoking is obvious since all patients are smokers. From all published cases, only two developed a malignancy with an uncertain association with PPBL. We have been monitoring our patient for 6.5 years without any evidence of the development of a lymphoma.

Functional T-cell anergy in a case of persistent polyclonal B-cell lymphocytosis

The T-cell population of a patient with persistent polyclonal B-cell lymphocytosis (PPBL) presenting with an intermittent Epstein-Barr virus (EBV)-associated disease was studied. Unstimulated T-cells did not express CD40 ligand (CD40L), whereas activation with IL-2 led to expression of this costimulatory molecule. CD40L expression was inhibited upon incubation with the supernatant of an EBV-positive B-cell line (SM) which had been grown spontaneously from the patient's peripheral blood cells. The supernatant of SM cells effectively inhibited cytotoxic T-cells. Elevated levels of IL-10, TNF-alpha and soluble CD40 were found in the supernatant of SM cells. Additionally, enhanced levels of LMP-1 protein were detected.

Polyclonal B-cell lymphocytosis mimicking malignant lymphoma in a newborn

We describe a 17-day-old newborn with fever and peripheral blood lymphocytosis. The circulating lymphocytes were large with lobulated and nucleolated nuclei. Their immature and uniform appearance raised the possibility of malignant lymphoma in the leukemic phase. Immunophenotypic study, however, showed that the lymphocytes were CD19(+) B cells with expression of both kappa and lambda light chains. Molecular biology study confirmed a polyclonal nature of the immunoglobulin heavy-chain gene. Cytogenetic analysis showed a normal karyotype, and viral cultures and serologic studies yielded negative results. The polyclonal lymphocytosis was self-limiting and disappeared within a month.

Definition and diagnosis of sporadic and familial chronic lymphocytic leukemia

This article describes the main defining criteria for chronic lymphocytic leukemia (CLL) and its differential diagnosis from closely related B-cell disorders. In addition to the morphology of circulating lymphocytes, the key diagnostic aid is the "CLL score" based on the typical immunophenotype of CLL as ascertained with five reagents: CD5, CD23, CD79b (or CD22), FMC7, and intensity of SmIg staining. The concepts of polyclonal and monoclonal B-cell lymphocytosis are defined with focus on the latter and its incidence in elderly individuals and its significant increase in healthy relatives from CLL families. The value of flow cytometry in the analysis of minimal residual disease after therapy also is discussed with a comparison with findings in bone marrow trephine biopsies. No candidate gene has been linked to the high incidence of CLL (10%) seen in families of patients with this disease.

Chromosomal instability and ATR amplification gene in patients with persistent and polyclonal B-cell lymphocytosis (PPBL)

Forty-three patients with persistent and polyclonal B-cell lymphocytosis (PPBL) were studied. The PPBL diagnosis was based on the presence of a polyclonal lymphocytosis and the detection of binucleated lymphoid cells on peripheral blood examination. In order to define the cytogenetic profile in these patients, conventional cytogenetic analysis and fluorescence in situ hybridization were performed at diagnosis in all patients and also at follow-up in 10 patients. When excluding + i(3q) and PCC, chromosomal instability is a common occurrence in PPBL and is characterized by other independent clonal abnormalities, del(6q), + der(8) or + 8, polyploid karyotype, structural changes, aneuploidy and/or non clonal chromosomal aberrations with either loss or more frequently gain of chromosomes. These data show the presence of a chromosomal instability in 67.5% of PPBL patients. Finally, ATR amplification was detected by hybridization with BAC probe 26217 in + i(3q) positive metaphase cells. No ATR deletion was observed in the + i(3q) negative B-cells. As the natural history of PPBL remains unclear, it is necessary to diagnose PPBL patients and useful to recommend a careful and continued long follow-up in all PPBL patients.

Intravascular bone marrow accumulation in persistent polyclonal lymphocytosis: a misleading feature for B-cell neoplasm

Persistent polyclonal B-cell lymphocytosis is usually reported in young smoking women. Whether this syndrome represents a premalignant or benign disease remains unclear. Indeed, because of the association of Bcl-2/IgH rearrangement and cytogenetic abnormalities, such cases may be misdiagnosed as the leukemic phase of a non-Hodgkin's lymphoma. We report eight new cases of persistent polyclonal B-cell lymphocytosis, which displayed a misleading bone marrow histological pattern, that is, intravascular B-cell infiltrate, constantly associated with Bcl-2 immunohistostaining, as seen in some lymphoma. We also show the absence or low expression of adhesion molecules on persistent polyclonal B-cell lymphocytes, suggesting that migration abnormalities might lead to bone marrow and peripheral blood accumulation. Although most cases presented multiple Bcl-2/IgH gene rearrangements and appeared to be polyclonal, oligoclonal expansion was identified in one out of eight patients, yet was not associated with clinical aggressiveness. The occasional reports of oligoclonal IgH and Bcl-2/IgH rearrangements in this disorder suggest that polyclonal expansion may be followed by the emergence of a predominant clone. However, the benign clinical course and lack of biological evolution in most cases imply that it is mandatory to distinguish this disorder from other malignant lymphoproliferations, so that unnecessary aggressive therapy can be avoided.

B-chronic lymphocytic leukemia: practical aspects

B-CLL is the most common adult leukemia in the Western world. It is a neoplasia of mature looking B-monoclonal lymphocytes co-expressing the CD5 antigen (involving the blood, the bone marrow, the lymph nodes and related organs). Much new information about the nature of the neoplastic cells, including chromosomal and molecular changes as well as mechanisms participating in the survival of the leukemic clone have been published recently, in an attempt to elucidate the biology of the disease and identify prognostic subgroups. For the time being, clinical stage based on Rai and Binet staging systems remains the strongest predictor of prognosis and patients' survival, and therefore it affects treatment decisions. In the early stages treatment may be delayed until progression. When treatment is necessary according to well-established criteria, there are nowadays many different options. Chlorambucil has been the standard regimen for many years. During the last decade novel modalities have been tried with the emphasis on fludarabine and 2-chlorodeoxyadenosine and their combinations with other drugs. Such an approach offers greater probability of a durable complete remission but no effect on overall survival has been clearly proven so far. Other modalities, included in the therapeutic armamentarium, are monoclonal antibodies, stem cell transplantation (autologous or allogeneic) and new experimental drugs. Supportive care is an important part of patient management and it involves restoring hypogammaglobulinemia and disease-related anemia by polyvalent immunoglobulin administration and erythropoietin respectively.

Dicentric chromosome 3 associated with binucleated lymphocytes in atypical B-cell chronic lymphoproliferative disorder

Binucleated lymphocytes on blood smear are known in PPBL characterized by stable and polyclonal lymphocytosis, polyclonal increase of serum IgM, HLA DR7 and strong correlation with additional i(3q) and premature chromosome condensation. In this disorder some reports of clonal Ig rearrangement suggest a follow up of these patients with immunological and genetic studies. Binucleated lymphocytes are rarely described in other clonal B-CLPD as B-CLL or marginal zone B-cell lymphoma (MZL). Chromosome 3 abnormality is never described in B-CLL but trisomy 3 represents the most consistent abnormality characterizing the MZL. We report in a man without previous medical history an unusual B-CLPD with monoclonal lymphocytosis CD5-, characteristic cytology (particularly binucleated lymphocytes) and chromosomic abnormality as dicentric chromosome 3 never previously described in B-CLPD. In this case lymphocytosis is persistent and stable over 24 months, cytologic immunologic and chromosomic abnormalities are unchanged. We discuss the nosologic place of this atypical B-CLPD closely related to PPBL and MZL with at the moment, after 24 months, a quiet evolution that imply nevertheless a careful follow up with regular cytologic, immunological and genetic studies to clarify the issue.

Persistent polyclonal B lymphocytosis: an expansion of cells showing IgVH gene mutations and phenotypic features of normal lymphocytes from the CD27+ marginal zone B-cell compartment

Persistent polyclonal B-cell lymphocytosis (PPBL) is an unusual and benign lymphoproliferation characterized by a polyclonal expansion of B lymphocytes, whose nature remains undetermined. The phenotypic analysis of three cases revealed that these cells were CD27+ IgM(high) CD21(high) CD5(low) and CD23(low), a phenotype associated with the normal marginal zone (MZ) B-cell compartment. As MZ B cells have initiated immunoglobulin (Ig)V gene somatic mutations, PPBL IgVH genes were sequenced. An average of 73% of these sequences were mutated. The mean number of mutation per sequence was 6.9, a number similar to those observed in the MZ B-cell compartment.

Persistent polyclonal B-cell lymphocytosis

We present a case of persistent polyclonal B-cell lymphocytosis (PPBL). This syndrome is characterized by a persistent lymphocytosis with circulating atypical binucleated lymphocytes. The patient had serological evidence of a previous EBV infection, had raised polyclonal serum IgM levels and was a heavy smoker. No malignancy was detected.

Upstream mediators of the Fas apoptotic transduction pathway are defective in B-chronic lymphocytic leukemia

Data concerning the presence and the functionality of Fas receptor in malignant B-cells are controversial. We have analyzed Fas molecules on B-cells from patients with B-chronic lymphocytic leukemia (B-CLL) cells. We observed a large variability, both of percentage of Fas-positive cells and of intensity of Fas level. Fas triggering was inefficient in inducing apoptosis whatever the number of Fas-positive B-cells, the amount of Fas receptors. B-cells were also resistant to etoposide treatment, but able to undergo apoptosis after dexamethasone treatment. We suggest that the Fas apoptotic pathway is altered in B-CLL patients at the initial step(s) of apoptotic machinery.

Persistent polyclonal B-cell lymphocytosis: further evidence for a genetic disorder associated with B-cell abnormalities

Persistent polyclonal B-cell lymphocytosis (PPBL) is an intriguing disorder diagnosed predominantly in women, usually cigarette smokers, characterized by an increase in the number of polyclonal B lymphocytes. Abnormality of the B-cell population is also evidenced by the presence of multiple bcl-2/Ig gene rearrangements and the finding of an additional long arm chromosome 3q+ (i3)(q10) within a significant proportion of B cells. The physiopathology of PPBL is unknown but its association with the HLA DR7 phenotype suggests a possible genetic disorder. To further determine whether PPBL has a genetic predisposition, we have undertaken an extensive study in a large family of a patient diagnosed with PPBL. Three individuals among the first-degree relatives presented all the criteria for a diagnosis of PPBL. A slight increase in serum IgM without evidence of B-cell proliferation was shown in two additional siblings. Multiple bcl-2/Ig gene rearrangements, a typical feature of PPBL, were identified in 8/10 individuals among first-degree relatives. A statistically significant association was found between the presence of these rearrangements and of a paternal HLA haplotype. We conclude that PPBL has a familial occurrence suggesting an underlying genetic defect. The development of the complete syndrome probably relies on unidentified additional co-factors.

Overview. Cytogenetic analysis in haematology

Cytogenetic analysis has contributed greatly to our understanding of the nature of leukaemia and lymphoma. Study of these two groups of diseases has revealed general truths about the nature of the neoplastic process. Cytogenetic analysis has demonstrated that haematological neoplasms result from a somatic mutation occurring in a haemopoietic, lymphoid or multipotent stem cell. Complete remission has been related to disappearance of the clone of cells bearing the mutation whereas the occurrence of clonal evolution has often been found to be indicative of increasingly aggressive disease. Cytogenetic analysis of leukaemias and lymphomas has led to the discovery of numerous proto-oncogenes; these generally play a crucial role in proliferation and differentiation of normal cells with a perturbation of their function leading to neoplasia. In addition, cytogenetic evidence has suggested a role for loss of function of cancer-suppressing genes in haematological neoplasms. Cytogenetic analysis has also made major contributions to precise diagnosis and to the assigning of prognosis and, furthermore, by identifying good and poor prognostic groups has improved the management of patients. Good-prognosis patients have been spared unnecessary treatment and, conversely, more intensive treatment for some diseases associated with a cytogenetic abnormality that was previously indicative of a poor prognosis has improved the outcome for these patients.

An unusual form of persistent polyclonal B lymphocytosis in an infant

We report a case of persistent polyclonal lymphocytosis in an infant. The circulating lymphocytes were of a small to medium size and a small proportion were larger and had lymphoplasmacytoid features. The presence of either an infectious or mutagenic agent was excluded. The polyclonal B-cell nature of the lymphocyte was demonstrated by immunological markers and confirmed by Southern blot analysis and by polymerase chain reaction targeting immunoglobulin genes. In contrast to the common form of polyclonal lymphocytosis, this case was not associated with HLA-DR7 and/or abnormalities of chromosome 3, p53 or Bcl2/IgH. Whether this lymphocytosis represents a premalignant or a benign condition remains uncertain, although there has been no progression to date.

[Polyclonal B lymphocytosis and hyper-IgM: immunodeficiency and/or benign lymphoid proliferation associated with tobacco?]

PURPOSE

To study the association of polyclonal B-cell lymphocytosis with binucleated lymphocytes with clinical manifestations suggesting the existence of an immunodeficiency, to evaluate the effect of cigarette smoking on this 'benign lymphoid proliferation', to analyze the clonality of lymphocytes, to determine the levels of immunoglobulins (Ig) G, A, M.

METHODS

Description and analysis of the results obtained in four patients and literature review.

RESULTS

Polyclonal B-cell lymphocytosis is associated with both a decrease in IgA and IgG and an increase in IgM. Recurrent infectious episodes (bronchitis) were observed in two patients. Transient smoking cessation allowed a decrease in lymphocytosis and IgM levels in two patients. No hematological malignancy occurred during the follow-up, while biological abnormalities persisted.

CONCLUSION

Persistent polyclonal B-cell lymphocytosis may be associated with minor clinical features of immunodeficiency. Smoking cessation may sometimes lead to a decrease in lymphocytosis and IgM.