Polyclonal B-cell lymphocytosis with hairy cell appearance: hairy B-cell lymphoproliferative disorder

A 72-year-old woman was referred to our hospital for evaluation of leukocytosis revealed by a medical examination. Her physical examination demonstrated no splenomegaly and no palpable lymph nodes. Her white cell count was 10,900/microl with atypical lymphocytosis (84.5%). Her hemoglobin concentration was 10.4 g/dl, and platelet count 151,000/microl. On peripheral blood smears, the atypical lymphocytes had a hairy cell-like appearance, and phase-contrast microscopic and transmission electron microscopic findings revealed the lymphocytes had many long surface microvilli. Flowcytometric analysis of peripheral blood lymphocytes identified expanded B-lymphocytes as having the IgG+, CD5- CD10- CD11c+ CD19+ CD20+ CD23- CD25- and CD103- cell surface phenotype. Serum electrophoresis disclosed polyclonal elevation of IgG and IgM (2620 mg/dl and 840 mg/dl, respectively). No light-chain restriction and a polyclonal VH gene rearrangement pattern indicated the polyclonal proliferation of B cells. The patient was a nonsmoker and had HLA-DR4, as in previous reports which have suggested an association between hairy B-cell lymphoproliferative disorder (HBLD) and HLA-DR4. No chromosome 3 abnormality was observed. These findings were consistent with the characteristics of HBLD, but differed in some respects from those of persistent polyclonal B-cell lymphocytosis (PPBL). Therefore, we diagnosed this patient as having HBLD.     

Treating patients with lupus with B-cell depletion

A new era in the treatment of systemic lupus erythematosus has dawned with the increasing introduction of monoclonal antibodies and other approaches, that target the key molecules involved in the pathogenesis of the disease. At present the ability to block the CD20 molecule on those B cells that carry this marker has proved the most effective way to treat patients resistant to conventional immunosuppressive drugs. However, these studies have all been open label and the results of double blind controlled studies are eagerly awaited.     

Colony-stimulating factors in B-cell colony formation in patients with B-cell chronic lymphocytic leukemia

A new in vitro colony growth assay system method was found to be reliable in its use for evaluating B-cell proliferation in normal subjects and in 9 patients with B-cell chronic lymphocytic leukemia (B-CLL). The method is based on a phytohemagglutinin (PHA)-stimulated monocyte and T-cell-conditioned medium (PHA-MTCM) composed of PHA, silica, normal monocytes and normal T cells. The number of colonies proliferated was significantly greater in 5 patients who had not undergone treatment than in normal subjects (1,417 +/- 660 vs. 661 +/- 119) (p less than 0.002). Normal cultured B-cell colonies were shown to be 71% surface IgM colonies, and 6% cytoplasmic IgA colonies with the appearance of blastic cells. B-CLL colonies, on the other hand, were demonstrated to be monoclonal with the same CLL circulating cells being retained. We also studied the effect of interleukin-2 (IL-2) on B-cell colony growth assay in 4 patients with B-CLL cells. Only 1 patient with M protein responded to IL-2, proliferated and expressed IL-2 receptors. Although 3 patients without M protein did not respond to IL-2, they did respond to the supernatant, and they proliferated but expressed no IL-2 receptors.     

Primary effusion lymphoma with B-cell phenotype

We describe here a case of primary effusion lymphoma that occurred in a 78-year-old woman. She was successively treated with prednisolone but died 15 months after the diagnosis of primary effusion lymphoma. The immunohistochemistry revealed the neoplastic cells to be CD19(+), CD20(+), CD21(+), Sm-Ig(+), and HLA-DR(+). This patient exhibited clonal IgH and clonal kappa light chain gene rearrangement, indicating a B-cell origin. The present case was distinguished from the majority cases of HHV-8-positive primary effusion lymphoma. Here we present clinical details of response to therapy in this case.     

Double B-cell malignancies with simultaneous onset

We encountered a case of a 59-year-old female who simultaneously contracted a non-Hodgkin lymphoma (NHL) and a plasma cell neoplasm. The patient consulted her physician about her abdominal tumor and anemia in March 1999. She was diagnosed as having NHL (follicular center lymphoma, grade I, stage IIA) after an open tumor biopsy, and treated by cycles of CHOP chemotherapy which resulted in complete remission. However, the patient's abdominal tumor appeared again in March 2000 and she was hospitalized at the Ehime University Hospital. A tumor biopsy was performed laparoscopically at that time. Follicular lymphoma (with positive LCA, L-26, and bcl-2 immuno-staining) with the development of retroperitoneal fibrosis was diagnosed again. When a bone marrow puncture was performed because of a condition of monoclonal gammopathy which had continued for two years, a smoldering myeloma was additionally diagnosed. This diagnosis was made after the presence of IgG-lambda M protein when the marrow showed an increase in the number of plasma cells. In a Southern blot analysis which studied the abdominal tumor and the bone marrow cells, each B-cell tumor had a different IgH gene rearrangement pattern. Therefore, this case was diagnosed as an example of the simultaneous existence of two different B-cell tumors. Double cancers in hematological malignancies are very rare and this was thought to be an interesting case.     

Hand-mirror-cell variant of B-cell lymphoma with hypercalcemia

The first (to my knowledge) case of confirmed hand-mirror cell (HMC) non-Hodgkin's lymphoma is described in a 56-year-old white woman. Surface-marker analysis indicated that the cells were B cells with surface IgM (lambda). The HMC phenomenon was considered to be real since it was seen on both Wright-Giemsa and supravital stains. In addition, this patient had uncontrollable hypercalcemia and unusual bone-scan findings. The significance of HMC and hypercalcemia in non-Hodgkin's lymphoma is discussed.     

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.     

Recombinant immunotoxin against B-cell malignancies with no immunogenicity in mice by removal of B-cell epitopes

Many nonhuman proteins have useful pharmacological activities, but are infrequently effective in humans because of their high immunogenicity. A recombinant immunotoxin (HA22, CAT8015, moxetumomab pasudotox) composed of an anti-CD22 antibody variable fragment fused to PE38, a 38-kDa portion of Pseudomonas exotoxin A, has produced many complete remissions in drug-resistant hairy-cell leukemia when several cycles of the agent can be given, but has much less activity when antibodies develop. We have pursued a strategy to deimmunize recombinant immunotoxins by identifying and removing B-cell epitopes. We previously reported that we could eliminate most B-cell epitopes using a combination of point mutations and deletions. Here we show the location and amino acid composition of all of the B-cell epitopes in the remaining 25-kDa portion of Pseudomonas exotoxin. Using this information, we eliminated these epitopes to produce an immunotoxin (HA22-LR-8M) that is fully cytotoxic against malignant B-cell lines, has high cytotoxic activity against cells directly isolated from patients with chronic lymphocytic leukemia, and has excellent antitumor activity in mice. HA22-LR-8M does not induce antibody formation in mice when given repeatedly by intravenous injection and does not induce a secondary antibody response when given to mice previously exposed to HA22. HA22-LR-8M also has greatly reduced antigenicity when exposed to sera from patients who have produced antibodies to HA22. The properties of HA22-LR-8M make it an excellent candidate for further clinical development.     

Incidence and clinicobiologic characteristics of leukemic B-cell chronic lymphoproliferative disorders with more than one B-cell clone

Leukemic B-chronic lymphoproliferative disorders (B-CLPDs) are generally believed to derive from a monoclonal B cell; biclonality has only occasionally been reported. In this study, we have explored the incidence of B-CLPD cases with 2 or more B-cell clones and established both the phenotypic differences between the coexisting clones and the clinicobiologic features of these patients. In total, 53 B-CLPD cases with 2 or more B-cell clones were studied. Presence of 2 or more B-cell clones was suspected by immunophenotype and confirmed by molecular/genetic techniques in leukemic samples (n = 42) and purified B-cell subpopulations (n = 10). Overall, 4.8% of 477 consecutive B-CLPDs had 2 or more B-cell clones, their incidence being especially higher among hairy cell leukemia (3 of 13), large cell lymphoma (2 of 10), and atypical chronic lymphocytic leukemia (CLL) (4 of 29). In most cases the 2 B-cell subsets displayed either different surface immunoglobulin (sIg) light chain (n = 37 of 53) or different levels of the same sIg (n = 9 of 53), usually associated with other phenotypic differences. Compared with monoclonal cases, B-CLL patients with 2 or more clones had lower white blood cell (WBC) and lymphocyte counts, more frequently displayed splenomegaly, and required early treatment. Among these, the cases in which a CLL clone coexisted with a non-CLL clone were older and more often displayed B symptoms, a monoclonal component, and diffuse infiltration of bone marrow and required early treatment more frequently than cases with monoclonal CLL or 2 CLL clones.     

B-cell biology

In recent years, our understanding of B-cell biology and the roles of B cells in normal immune responses and autoimmunity has increased dramatically. We no longer think of B cells simply as antibody factories. It is clear that these diverse and exquisitely regulated cells may contribute in a multitude of ways to immune responses. Animal models, clinical trials of biologic agents, and the ever expanding field of molecular biology have made great contributions to our current knowledge. With this improved understanding, we are afforded the opportunity to consider numerous potential therapeutic targets for treating autoimmune disease. As this growing science evolves, we can expect to see the advent of new therapies and new hope for patients who are afflicted with these disorders.     

Angioimmunoblastic T-cell lymphoma complicated with EBV-associated B-cell lymphoma

A 71-year-old man with high fever and enlargement of the bilateral submandibular, cervical and inguinal lymph nodes was hospitalized at Hiroshima University Hospital. The immunohistochemical and pathologic findings from the biopsy specimens led to the diagnosis of angioimmunoblastic T-cell lymphoma (AILT) with a cluster of CD20-positive cells. Flow cytometry analysis by two-color staining did not reveal any neoplastic B cells. Southern blot analysis showed rearrangement of both the IgH gene and the TCR gene. Furthermore, PCR of the IgH gene using DNA extracted from purified CD19-positive cells from the lymph nodes showed a monoclonal band, and it was different from that of purified CD138-positive cells from the bone marrow. Furthermore, monoclonal Epstein-Barr virus (EBV) infection was detected with PCR using the SL18 and SL19 primers of the LMP-1 gene. Numerous EBER-positive cells were detected diffusely in the lymph nodes. These findings indicated a diagnosis of angioimmunoblastic T-cell lymphoma complicated with EBV-associated B-cell lymphoma, and that immunodeficiency in AILT led to an expansion of EBV infected B-cells.     

Monoclonal B-cell lymphocytosis (MBL) with normal lymphocyte counts is associated with decreased numbers of normal circulating B-cell subsets

Monoclonal B-cell lymphocytosis (MBL) with normal lymphocyte counts is associated with decreased numbers of normal circulating B-cell subsets.Little is known about the distribution of normal lymphoid cells and their subsets in the peripheral blood (PB) of subjects with monoclonal B-cell lymphocytosis (MBL). In our study, we compared the absolute number of PB lymphoid cells and their subpopulations in 95 MBL cases with normal lymphocyte counts vs. 617 age-/sex-matched non-MBL healthy subjects (controls), using highly sensitive flow cytometry. MBL cases showed significantly reduced numbers of normal circulating B-cells, at the expense of immature and naive B-cells; in addition, CD4+CD8+ double-positive T-cells and CD8+ T-cells were significantly lower and higher vs. controls, respectively. Moreover, most normal B-cell subsets were significantly decreased in PB at >1% MBL-counts, vs. "low-count" MBL cases, and lower amounts of immature/naive B-cells were detected in biclonal (particularly in cases with coexisting CLL-like- and non-CLL-like B-cell clones) vs. monoclonal MBL subjects. In summary, our results show imbalanced (reduced) absolute numbers of recently produced normal circulating B-cells (e.g., immature and na?ve B-cells) in MBL, which becomes more pronounced as the MBL cell count increases.