Richter's syndrome with different immunoglobulin light chains and different heavy chain gene rearrangements

In a patient with Richter's syndrome, the chronic lymphocytic leukemia (CLL) expressed lambda, mu, and delta immunoglobulin (lg) chains and the non-Hodgkin lymphoma (NHL) kappa, mu, and delta lg chains. The difference in lg light chain expression suggests that the CLL and NHL are independent malignancies, or that the oncogenic event occurred in a B cell differentiation stage after the heavy chain gene rearrangements but before the selection of the light chain. Analysis of DNA by Southern blotting revealed that the lg heavy chain genes of the two malignancies were rearranged in a different way. We therefore conclude that in this patient the NHL cannot be regarded as a progression of the CLL but should most likely be considered as an independent B cell malignancy, which arose in a susceptible host.     

Gamma heavy chain "disease": heterogeneity of the clinicopathologic features. Report of 16 cases and review of the literature

This review underscores the diversity of the clinical manifestations and hematopathological features of gamma heavy chain disease based on the detailed report of 16 patients evaluated in our chemical department, the analysis of 12 cases diagnosed in our laboratory, and the study of 81 cases previously reported. This condition is defined by the presence in the serum of immunoglobulin molecules composed of deleted gamma heavy chains devoid of light chains. The production by the monoclonal B cells of these peculiar proteins appears to result from multiple defects (deletions, insertions, and mutations) in both heavy and light chain genes leading to abnormal mRNA splicing. Gamma heavy chain disease is currently underdiagnosed. The diagnosis established by immunoelectrophoresis using specific antisera combined, in some instances, with the immunoselection procedure, can easily be missed on serum electrophoretic patterns: a narrow abnormal band suggestive of a monoclonal component was found in only 10 of our 28 cases. The amount of heavy chain disease protein in urine ranges from trace to 20 g/day and is usually moderate. Gamma heavy chain disease most often presents as a lymphoproliferative disorder featured by lymphadenopathies, splenomegaly, and constitutional symptoms. Extra-hematopoietic tumor localizations, such as cutaneous or subcutaneous involvement or thyroid tumor, may occur. Autoimmune disorders, notably rheumatoid arthritis and autoimmune hemolytic anemia or thrombocytopenic purpura, are frequent (26% of cases). There is no specific histological pattern. The most frequent is a pleomorphic malignant lymphoplasmacytic proliferation mainly seen in bone marrow and lymph nodes. Some cases present with a predominantly plasmacytic proliferation or chronic lymphocytic leukemia. Other patients are affected with non-Hodgkin lymphoma of various morphologic types. Immunocytologic studies showed that a gamma heavy chain disease protein may occur in the context of a double monoclonal lymphoproliferative process or in various B or T cell malignancies that are not directly involved in the production of the abnormal immunoglobulin. In some patients, the histologic appearance of the enlarged lymphoid organs showed only a moderate lymphoplasmacytic infiltration of uncertain malignancy. More important, some patients showed no evidence of an underlying lymphoproliferative disorder after several years of follow-up. The clinical course of gamma heavy chain disease varies from an asymptomatic state to a rapidly progressive malignancy. The choice of therapy should entirely rely on the underlying clinicopathologic features, without taking into account the presence of the abnormal protein.(ABSTRACT TRUNCATED AT 400 WORDS)     

Molecular characterization of paediatric idiopathic hypereosinophilia

The hypereosinophilic syndromes (HES) include a group of heterogeneous diseases characterized by the persistent increase of the number of eosinophils in blood and bone marrow. Few cases of paediatric hypereosinophilia (pHES) have been described in the literature. Early identification of pHES that may evolve towards a lymphomyeloproliferative disease is relevant in light of prognostic and therapeutic implications. Molecular features of 10 pHES patients were analysed at presentation and during their clinical course, including analysis of BCR-ABL1 and FIP1L1/PDGFRA fusion genes, quantitation of WT1 gene copy number and clonality of T-cell receptor (TCR) and immunoglobulin heavy chain (IGH). All patients had normal karyotype and germline TCR configuration. Five children showed IGH clonality at presentation: of these, two developed a B non-Hodgkin lymphoma and a B-lineage acute lymphocytic leukaemia at six and 12 months respectively, two spontaneously reverted to a polyclonal IGH profile during the follow-up, and the last one persisted with pHES without B-clonal evolution after 19 months. One patient had a PDGFRA/FIP1L1 fusion and achieved hematologic and molecular remission after imatinib therapy. IGH rearrangement was observed to be a frequent molecular feature of pHES and may precede B-cell clonal expansion and evolution into B-cell malignancies in children.     

Immunoglobulin gene rearrangements in adult non-Hodgkin's lymphoma

Southern blotting was employed to analyze the immunoglobulin heavy and light chain genes and the gene for the T cell receptor beta chain in genomic DNA derived from the tumor specimens of 120 adults with pathologically classified and immunotyped non-Hodgkin's lymphoma and B cell chronic lymphocytic leukemia. In a consecutive series of 100 patients, one or two rearranged heavy chain genes could be detected in each of the 80 samples expressing clonal surface immunoglobulin. The kappa gene was rearranged in 70 percent of kappa-bearing tumors and in 23 percent of lambda-bearing specimens. Furthermore, a rearranged immunoglobulin gene was also observed in 21 of 29 lymphomas (nine from the consecutive series and 20 selected for surface immunoglobulin-negative status) in which B cell lineage was in doubt because of absent clonal surface immunoglobulin. These findings indicate that most cases of lymphoma and lymphocytic leukemia in adults are of B cell lineage, even when phenotypic evidence is inconclusive. The exceptional cases (only 3 percent in the consecutive series) were of either follicular lymphoma or diffuse large cell (histiocytic) lymphoma subtype; the lineage in cases of diffuse lymphocytic lymphoma or chronic lymphocytic leukemia was never in doubt. Although the convenience of surface marker analysis assures its continuing clinical application, gene study resolves indeterminate cases and extends the understanding of the pathogenesis of lymphoproliferative disease.     

The ultrastructural localization of immunoglobulin in chronic lymphocytic lymphoma cells: changes in light and heavy chain distribution induced by mitogen stimulation

The distribution of light and heavy immunoglobulin chains in chronic lymphocytic leukemia (CLL) cells has been investigated at the ultrastructural level using an immunoperoxidase technique. Light chains were localized in the lumens of the perinuclear space and rough endoplasmic reticulum, while staining for heavy chains was weak or negative and generally confined to the membranes of the rough endoplasmic reticulum. This pattern is consistent with immunoglobulin biosynthetic studies on CLL cells in which light chains are synthesized in excess over heavy chains and secreted as the exclusive immunoglobulin product. The pokeweed mitogen stimulation of two populations of CLL cells for 6 days resulted in a balanced synthesis and secretion of light and heavy chains that was reflected in concomitant change in light and heavy chain distribution and intensity of staining using the immunoperoxidase technique.     

Aggressive B-cell lymphoma with dual surface immunoglobulin light-chain expression

Dual surface immunoglobulin light-chain expression in B-cell malignant neoplasm is a rare event, and has been predominantly reported in chronic lymphocytic leukemia. Herein, we report a case of aggressive B-cell lymphoma with kappa/lambda-dual surface immunoglobulin light-chain expression of a 69-year-old woman. The lymphoma cells were positive for CD5, CD19, CD20, HLA-DR, Ig kappa and Ig lambda. Southern blot analysis confirmed rearranged bands for both light chains with a monoclonal heavy chain rearrangement. She was treated with a combination of rituximab and CHOP regimen, but died of the progressive disease. To our knowledge, this is the first case of aggressive B-cell lymphoma showing dual kappa/lambda expression; the possible mechanisms of abnormal light chain expression are discussed.     

胃淋巴增生性疾病IgH基因重排的检测及意义

目的 探讨免疫球蛋白重链（ＩｇＨ）基因单克隆性重排的检测对胃ＭＡＬＴ淋巴瘤的诊断及鉴别诊断价值。方法 应用半巢式聚合酶链反应技术检测石蜡包埋的３１例胃ＭＡＬＴ淋巴瘤、２６例淋巴细胞性胃炎及１１例对照标本免疫球蛋白重锭基因重排的克隆性。引物选用互补于ＩｇＨ基因Ｖ区及Ｊ区保守序更的Ｆｒ２,Ｆｒ３。结果 （１）用Ｆｒ３为引物扩增,７４．２％的胃ＭＡＬＴ淋巴瘤获得单克隆性重条带;联合Ｆｒ２扩增,可使其检出     

Triclonal gammopathy in an extranodal non-Hodgkin lymphoma patient

The case of a patient with an extranodal non-Hodgkin lymphoma and three M-components (IgGkappa + IgGlambda + IgMlambda) in the serum is described. Three separate populations of M-component producing cells have been identified. Since a kappa-->lambda chain switch is not demonstrated, the synthesis of IgGkappa and IgGlambda by two distinct clones is obvious. IgMlambda and IgGlambda M-components are synthesized by two different plasma cell populations that could represent two unrelated cell clones or, alternatively, two subclones originated by a common precursor. After chemotherapy the IgGlambda M-component is replaced by heavy gamma chains without evidence of lambda light chains.     

Successful treatment of µ-heavy chain disease with fludarabine monophosphate: A case report

Heavy chain diseases (HCD) are monoclonal lymphoproliferative disorders of B-cells characterized by the synthesis of truncated heavy chains without associated light chains. In patients with mu-HCD, which is a very rare form of HCD, neoplastic cells produce immunoglobulin M heavy chain. The prognosis for patients with mu-HCD is poor, and there is no specific treatment for mu-HCD. In this report, we present a patient with mu-HCD accompanied by splenomegaly and thrombocytopenia. We treated this patient with the fludarabine monophosphate therapy we use for patients with B-cell chronic lymphocytic leukemia. After 5 courses of fludarabine monophosphate treatment, the splenomegaly and thrombocytopenia improved. Fludarabine monophosphate therapy may be a new strategy to improve the prognosis of patients with mu-HCD.     

Maladie des chaînes lourdes de type gamma associée à un lymphome B diffus à grandes cellules dans un contexte de myélodysplasie

IntroductionHeavy chain disease is a rare entity characterized by the production of incomplete immunoglobulin heavy chain without associated light chain. It is a B-cell lymphoproliferation, categorized according to the immunoglobulin involved. It is often associated with lymphomas but also with autoimmune diseases.ObservationWe report the case of a 70-year-old patient who presented a gamma-type heavy chain disease, associated with a diffuse large B-cell lymphoma in the context of myelodysplastic syndrome.ConclusionThis is the first case of diffuse large B-cell lymphoma associated gamma heavy chain disease described in the context of myelodysplastic syndrome.     

B-cell receptors and heavy chain diseases: guilty by association?

Heavy chain diseases (HCDs) are B-cell proliferative disorders characterized by the production of monoclonal, incomplete, immunoglobulin (Ig) heavy chains (HCs) without associated light chains (LCs). These abnormal HCs are produced as a consequence of HC gene alterations in the neoplastic B cells. HC gene alterations will also impact on surface HC, which is part of the B-cell receptor (BCR), a crucial player in lymphocyte activation by antigen. The selective advantage conferred to mutant cells by abnormal BCR without an antigen-binding domain may be explained by activation of ligand-independent signaling, in analogy to what has been shown for mutated oncogenic growth factor receptors. Here we review data obtained from mouse models showing abnormal, constitutive activity of HCD-BCR, and we discuss the possible mechanism involved, namely, aberrant spontaneous self-aggregation. This self-aggregation might occur as a consequence of escape from the chaperone immunoglobulin binding protein (BiP) and from the anti-aggregation effect of LC association. The concept of misfolding-induced signaling elaborated here may extend to other pathologies termed conformational diseases.     

Surface light chain phenotype in indolent lymphomas: lack of prognostic significance

The indolent follicular and diffuse lymphomas are neoplasms of B-cell origin. In several other B-cell neoplastic disorders, including multiple myeloma, hairy cell leukemia, and chronic lymphocytic leukemia, the light chain isotype of the surface immunoglobulin has been reported to have prognostic significance. Patients with tumors expressing lambda light chains usually fare more poorly than those with kappa light chain-bearing tumours. We analyzed the clinical data and immunologic phenotype of 101 patients with indolent lymphoma. Eighty-nine of the 101 patients demonstrated surface immunoglobulin of only one light chain type (kappa-47, lambda-42). Patients in both groups were matched for known prognostic factors. There were no significant differences in disease-free survival or overall survival between the two groups or within histologic subtypes. These results indicate that the immunologic light chain phenotype in indolent lymphoma, unlike other B-cell neoplasms, is not a prognostic indicator of survival.     

Contribution of new immunoglobulin-derived biomarkers in plasma cell dyscrasias and lymphoproliferative disorders

New assays for serum immunoglobulin (Ig) free and heavy chain quantification were developed for routine clinical practice. Serum free light chain (sFLC) assay was shown to improve detection, management and prognostication in all plasma cell dyscrasias. More precisely, sFLC measurements proved to be prognostic for the progression of monoclonal gammopathy of undetermined significance and smoldering multiple myeloma (MM), became markers of response and survival in amyloid light-chain amyloidosis and contributed to accurate follow-up of patients with light chain and non secretory MM. In addition, sFLC and they ratio (sFLCR) were shown useful for the prognosis and monitoring of intact Ig myeloma; their evaluation was incorporated in the new uniform response criteria. sFLC or sFLCR were also observed abnormal in B-cell non-Hodgkin lymphoma/chronic lymphocytic leukemia (CLL). Moreover, increased sFLC levels, summated sFLC or abnormal sFLCR predict shorter overall survival in early-stage CLL while increased sFLC constituted an independent, adverse prognostic factor for event-free and overall survival in diffuse large B-cell lymphoma and Waldenstrom’s macroglobulinemia. Clinical applications of heavy Ig chain separately (HLC) measurements are more recent and mainly concern MM in which HLC deriving ratios correlated with parameters of disease activity and constituted an adverse survival marker.     

Follicular lymphoma immunoglobulin κ light chains are affected by the antigen selection process, but to a lesser degree than their partner heavy chains

Follicular lymphoma cells carry surface immunoglobulin whose heavy chain variable (V_H) regions exhibit considerable divergence from the aminoacid sequence predicted by the germline nucleotide sequence as a result of the somatic hypermutation process. The present study examined the extent of somatic hypermutation in follicular lymphoma κ light chain variable region (Vκ) genes about which the available data is limited. DNA extracted from fresh frozen lymph node tissue of 14 patients with follicular lymphoma at diagnosis was subjected to polymerase chain reaction (PCR) amplification aimed at detecting clonal V_H and V_L (L; light chain) gene rearrangements. Clonal Vκ gene rearrangements were detected in 10/14 cases. Amplified V_H and Vκ genes of these 10 cases were directly sequenced by the dideoxy-chain termination method. In all cases, rearranged V_H genes demonstrated numerous mutations clustering in the complementarity determining regions (CDRs), in keeping with previous reports. The degree of divergence of the rearranged Vκ genes from the closest homologous germline Vκ genes varied significantly. Furthermore, two patterns of mutations were observed: (i) in six cases (60%), mutations were most often of the replacement (R) type (changing the aminoacid sequence of the encoded polypeptide) in the CDRs and of the silent (S) type (leaving the aminoacid sequence of the encoded polypeptide unchanged) in the framework regions (FWRs) resulting in R:S ratios significantly greater than would have occurred by chance; (ii) in four cases (40%), very few or no mutations were observed and the distribution of mutations as well as the R:S mutation ratios did not differ significantly from what would have occurred by chance alone. These findings imply that, compared to their partner heavy chains, the κ light chains of follicular lymphoma neoplastic B-cells' surface immunoglobulin (sIg): (i) are less affected by somatic hypermutation; (ii) play a less significant role in the antigen selection process.     

Expression of mu and gamma immunoglobulin heavy chains in different cells of a cloned mouse lymphoid line

A cloned cell line derived from mouse bone marrow and transformed by Abelson virus is shown to synthesize two different heavy chains, mu and gamma 2B, in vitro. This characteristic is stable because it persists upon subcloning. Although most of the immunoglobulin-synthesizing cells produce either mu or gamma 2B heavy chains, a few cells contain both heavy chains, suggesting immunoglobulin class switching. Karyotypes show a complement of 41 chromosomes. Two copies of chromosome 12, to which immunoglobulin heavy chain structural genes have been assigned, were found. No light chain was found in either the mu- or the gamma 2B-producing cells. However, fusion of the cell line with a myeloma that synthesizes neither heavy nor light chains caused expression of kappa light chain in the hybridoma synthesizing mu chain. No light chain could be detected in the hybridomas synthesizing gamma 2B heavy chain.     

A serum heterodimer from hagfish (Eptatretus stoutii) exhibits structural similarity and partial sequence identity with immunoglobulin.

We have isolated, characterized, and partially sequenced immunoglobulin from the most primitive extant nonvertebrate craniate, the hagfish, a jawless fish that may have diverged from the vertebrate lineage more than 500 million years ago. The 160-kDa protein, which is a minor serum component, is composed of two different heavy chains of 69 and 74 kDa and a light chain of 29 kDa and resembles known immunoglobulin on the basis of an equimolar ratio of heavy and light chains, N-linked glycosylation of heavy chains, presence of intra- and interchain disulfide bonds, and polydispersity of each peptide chain. High molecular mass (polymeric) as well as low molecular mass (monomeric) forms were isolated from serum. The hagfish immunoglobulin is unique in that each heterodimer is composed of two different heavy chains and two light chains. The partial peptide maps and amino acid compositions of the two heavy chains differ; the chains do not crossreact immunologically. Slight crossreactivity of the 74-kDa heavy chain with antisera against purified shark immunoglobulin and some conservation of amino acid sequences, including those surrounding a cysteine, suggest that the isolated protein is an immunoglobulin.     

Urinary protein excretion patterns in reactive (secondary) systemic amyloidosis

Summary The urinary excretion of immunoglobulin light chains kappa and lambda, immunoglobulin G, transferrin, and beta-2-microglobulin was studied in 21 patients with nonimmunoglobulin-related amyloid nephropathy (secondary, type AA) associated with rheumatic disease and in 39 patients with glomerulopathy of nonamyloid origin, as well as in 22 patients with rheumatic disease without signs of nephropathy and in 15 healthy subjects. Patients with amyloidosis were found to have a higher ratio of excreted lambda/kappa light chains than patients with diabetic nephropathy or chronic glomerulonephritis. The increased lambda/kappa ratio was not dependent on the grade of proteinuria and was evident in patients with mild as well as heavy proteinuria. The ratio of lambda/kappa light chains in serum of patients with amyloidosis did not differ from that in healthy controls. The results suggest that amyloid deposition in the kidneys is associated with a selective alternation of the immunoglobulin light chain excretion in the urine.     

Monoclonal immunoglobulin deposition disease: light chain and light and heavy chain deposition diseases and their relation to light chain amyloidosis. Clinical features, immunopathology, and molecular analysis

Monoclonal immunoglobulin deposition occurs in tissues as Congo Red binding fibrils in light chain amyloidosis, as less structured deposits in light chain deposition disease, and as similar but distinct deposits in light and heavy chain deposition disease. The nonamyloid forms were found in 13 patients who had evidence of plasmacytic dyscrasia by the immunohistochemical detection of immunoglobulin light chains of kappa or lambda class (with or without staining for a single heavy chain isotype) and by the absence of amyloid P component in tissue sections that did not show the birefringence characteristic of amyloid after Congo Red staining. All but two of the patients presented with proteinuria with or without azotemia. Clinical syndromes involving other organ systems were less common but occasionally severe. Four patients had overt multiple myeloma. Three others had hypercalcemia and mild bone marrow plasmacytosis but no lytic lesions. Analyses of immunoglobulin synthesis in bone marrow cells from seven patients showed excess light chains in all and incomplete light chains or heavy chain fragments in six, regardless of whether an intact monoclonal protein or related subunit was in the serum or urine. The fibrillar (amyloidotic) and nonfibrillar forms of monoclonal immunoglobulin deposition occur either in overt multiple myeloma or in the course of less neoplastically aggressive plasmacytic dyscrasias. Bone marrow cells from patients with either type produce immunoglobulin fragments that are related to those deposited in the affected tissues.     

Lymphocyte surface characteristics in malignant lymphoma

The surface of lymphocytes obtained from fresh biopsy specimens from 41 patients with malignant lymphoma and from 30 normal subjects or patients with non-neoplastic lymphadenopathy were investigated. Immunoglobulin on the cell surface was used to identify B cells, whereas T cells were recognized by their reactivity with an antithymocyte antiserum and their ability to form rosettes with sheep erythrocytes. Normal and inflammatory lymph nodes were composed predominantly of T lymphocytes, as were nodes from 14 patients with Hodgkin's disease. Two thymomas were T cell proliferations, whereas a node from a patient with ataxia-telanglectasia was devoid of T lymphocytes. The presence of immunoglobulin on the cell surface indicated that 19 of 21 lymphocytic lymphomas were B cell proliferations, whereas the cells from 3 histiocytic lymphomas (reticulum cell sarcomas) and 1 mixed histiocytic and lymphocytic lymphoma were devoid of surface immunoglobulin. In immunoglobulin-positive tumors, one predominant heavy chain and one predominant light chain could usually be identified, thus establishing the clonal character of the neoplastic proliferation. Ten of 11 diffuse poorly differentiated lymphocytic lymphomas were composed of cells with large amounts of surface immunoglobulin, whereas only 1 of 5 diffuse well differentiated lymphocytic tumors contained such abundant surface immunoglobulin. The surface immunoglobulin data indicate the existence of at least two subspecies of B cell neoplasms. A small lymphocyte with sparse surface immunoglobulin proliferates as diffuse well differentiated lymphocytic lymphoma and chronic lymphocytic leukemia, whereas a larger lymphocyte with abundant surface immunoglobulin proliferates as diffuse poorly differentiated lymphocytic lymphoma and lymphosarcoma cell leukemia.