CD5+ persistent polyclonal B-cell lymphocytosis in a male

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.

Biclonal chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) is well characterized clinically and immunophenotypically. Demonstration of a monotypic CD19+, CD5+ B-cell population is central to the diagnosis. We report 2 cases of biclonal CLL. Two elderly men were encountered with an absolute lymphocytosis consisting of the typical CD5+, CD19+, CD23+ B-cell population seen in CLL; however, immunoglobulin light chain restriction by flow cytometry was not apparent as B cells expressed kappa or lambda light chains without a clear monotypic population. Molecular genetic analysis of flow cytometry-sorted cells (kappa and lambda populations) revealed in both cases 2 monoclonal B-cell populations. The characterization of these cases and a review of the issues surrounding biclonal CLL are presented.

[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.