Detection of immunoglobulin gene rearrangement in lymphoid malignancies of B-cell lineage by seminested polymerase chain reaction gene amplification

The Relevance of VDJ PCR Protocols in Detecting B-Cell Clonal Expansion in Lymphomas and Other Lymphoproliferative Disorders

Aims and background

The detection of immunoglobulin heavy chain variable (VH)-diversity (DH)-joining (JH) region gene rearrangement by polymerase chain reaction (VDJ PCR) has been recently proposed as a rapid approach to assess B-cell clonality in lymphoproliferative disorders. The aim of the present study was to determine the efficacy of VDJ PCR in a wide spectrum of lymphoproliferative disorders previously characterized by immunohistochemistry and Southern blot (SB).

Methods

83 SB-rearranged B-cell non-Hodgkin's lymphomas (NHL) of different histotype, 22 cases of SB-unrearranged classical Hodgkin's disease (HD), 18 cases of HIV-related reactive lymphadenopathy, and 4 frankly pre-lymphomatous lesions (MESA) in the course of Sjögren's syndrome were investigated by 2 different VDJ PCR protocols (FR3, FR2).

Results

The detection rate in NHL was 64% and 71% using the protocols FR3 and FR2, respectively. However, the overall VDJ PCR efficacy increased to 81% by combining the results of both protocols. In addition, differences in the combined, as well as in the single FR3 or FR2 protocol efficacy, were noted in the different NHL subgroups. B-cell clonality was also detected in 4/22 (18%) SB-unrearranged classical HD cases and in 2/18 (11%) reactive lymphadenopathy cases, whereas it was demonstrated in all the MESA lesions, 2 of them being SB-negative.

Conclusions

VDJ PCR represents a useful and rapid technique to detect B-cell clonality in NHL, although with some differences depending on the NHL histotype and the panel of primers employed. The technique may also be of value to investigate the possible progression of early B-cell clonal expansion into frankly B-cell malignancy and to contribute to the controversy about the clonal lineage origin of the putative HD malignant cells.

Chronic Myelomonocytic Leukemia Coexisting with B-cell Chronic Lymphocytic Leukemia

Coexistence of B-cell chronic lymphocytic leukemia (B-CLL) and chronic myelomonocytic leukemia (CMML) is an unusal event, and to our knowledge, only four such cases have been reported in the literature. We report a 68-year-old white woman in whom these two diseases were diagnosed concomitantly. The diagnosis was made on the basis of peripheral blood count, morphology and immunophenotyping, and bone marrow cytology and histology. Interphase FISH analysis detected a 13q14.3 deletion in lymphocytes nuclei and no such abnormality in monocytes nuclei. The PCR analysis of IgH gene rearrangement in the bone marrow, as well as the peripheral blood lymphocytes, showed two different monoclonal IgH configurations as the result of biallelic clonal rearrangement of IgH genes suggesting an origin of lymphocytes from B-cell progenitors. The patient was originally treated with prednisone 1 mg/kg/day because of progressive significant thrombocytopenia, without improvement. Subsequently, she received one course of cladribine (2-CdA). Significant reduction of lymphocytes in the peripheral blood was observed. However, rapid increase of monocytes was seen shortly after the 2-CdA treatment. Subsequently, she received hydroxyurea (1.5 g/day) without hematological improvement. The patient died in January 2003, three months after diagnosis because of progression of both leukemias and associated pneumonia. Possible etiopathogenic relationship between both disorders is discussed.

Minimal residual disease assessment in chronic lymphocytic leukaemia

The concept of minimal residual disease (MRD) eradication in chronic lymphocytic leukaemia (CLL) is a relatively new one, as conventional therapy with alkylating agents is relatively ineffective and responding patients almost always have a significant tumour burden remaining at the end of treatment. However, a variety of novel therapies is now yielding higher response rates, and responses of better quality are now routinely achieved. This progress in therapy has been paralleled by an improvement in laboratory assays, allowing detection of CLL cells to levels as low as ten CLL cells in a million leukocytes. In this chapter we briefly review the existing methods for MRD assessment, the clinical relevance of MRD eradication in CLL, and the therapies available to attain this endpoint.

Primary cutaneous marginal zone B-cell lymphoma in a patient with chronic lymphocytic leukaemia

Primary cutaneous marginal zone B-cell lymphoma (PCMZL) is a low-grade malignant lymphoma that presents in the skin with no evidence of extracutaneous localization at diagnosis. We present an 80-year-old woman with B-cell chronic lymphocytic leukaemia (CLL) who developed multifocal PCMZL lesions 14 months after CLL diagnosis. PCMZL was clonally similar to the original bone marrow (BM) CLL cells. The specific translocation t(14;18) (q32;q21) with breakpoints in IGH and BCL2 loci was found in a skin specimen, but was absent in BM and peripheral blood (PB) cells. In contrast, a 13q deletion was found in BM and PB CLL cells. The patient was treated with chlorambucil and complete response of PCMZL was achieved. To our knowledge this is the first patient with CLL in whom PCMZL has been diagnosed.

Richter syndrome first manifesting as cutaneous B-cell lymphoma clonally distinct from primary B-cell chronic lymphocytic leukaemia

Richter syndrome (RS) is a transformation to high-grade non-Hodgkin lymphoma in patients with chronic lymphocytic leukaemia (CLL). RS may develop in lymph nodes or rarely extranodally. Skin localization of RS has been described in only a few cases. We present a 77-year-old woman who developed isolated diffuse large B-cell lymphoma (LBCL) in the skin of the nose without any other symptoms of RS. The LBCL in the skin was clonally distinct from the original bone marrow CLL cells. Moreover, LBCL cells were positive for LMP-1 segment of Epstein-Barr virus and overexpressed p53 protein. The patient was successfully treated with CHOP (cyclophosphamide, doxorubicin, vincristine and prednisone) and adjuvant local radiotherapy.

Multiple myeloma in a patient with systemic lupus erythematosus, myasthenia gravis and non-familial diffuse palmoplantar keratoderma

The coexistence of autoimmune diseases and malignancies including lymphoproliferative diseases is often reported in the literature. Here we report an unusual case with two autoimmune diseases--myasthenia gravis (MG) and systemic lupus erythematosus (SLE) associated with unique palmoplantar keratoderma (PK) which preceded the development of multiple myeloma (MM) for twenty and seven years respectively. MG associated with non-malignant thymoma developed in 1981 and was successfully treated with thymectomy and physostigmine. Thirteen years later SLE was diagnosed and until now it is also accompanied by skin lesions corresponding to non-familial, diffuse palmoplantar keratoderma which is resistant to treatment. In 2001 the patient revealed inguinal and abdominal lymphadenopathy first diagnosed as extramedullary plasmacytoma and then as multiple myeloma on the basis of bone marrow infiltration and monoclonal gammopathy. Therapy with VAD regimen achieved complete remission of the MM and significant improvement of the skin changes lasting for six months. We failed to collect sufficient numbers of CD 34+ cells for peripheral blood stem cell transplantation. Now the malignancy is in partial remission after CHOP therapy and the skin lesions have returned to their initial status. To our knowledge, this is the first case to be reported with coexistence of these four diseases.

Second primary lymphoma or recurrence: a dilemma solved by VDJ rearrangement analysis

A lymphoma patient in remission that develops a second lymphoma is frequently assumed to have had a relapse of the original lymphoma. However, the second lymphoma may instead be a new lymphoma with a different clonal origin. Comparison of histological characteristics alone is insufficient in many cases to distinguish new lymphomas from recurrent lymphomas. In contrast, clonal origins of B-cell lymphomas can be reliably compared by VDJ rearrangement analysis of B-cell IgH genes. Simultaneous lymphomas have similarly been analyzed by this technique to determine whether or not both tumors share a common clonal origin. Application of VDJ rearrangement analysis in clinical research has been important for characterizing mechanisms of lymphoma development. Furthermore, this technique has the potential to improve treatment of lymphoma patients because management of recurrent lymphomas differs from that of new lymphomas.

Prognostic significance of molecular staging by PCR-amplification of immunoglobulin gene rearrangements in diffuse large B-cell lymphoma (DLBCL)

The prognostic value of the detection of peripheral blood (PB) and/or bone marrow (BM) involvement by polymerase chain reaction (PCR) amplification of rearranged immunoglobulin heavy chain (IgH) and immunoglobulin kappa light chain (Igkappa) genes was evaluated in 155 patients with diffuse large B-cell lymphomas (DLBCL). Immunoglobulin gene rearrangements (IgR) were detected in 35/155 (23%) patients. The presence of IgR in PB/BM was related to clinical stage (CS I-III vs CS IV; P<0.001), histopathological detection of BM involvement (P<0.001), and the International Prognostic Index (P<0.001). IgR-positive cases had a significantly lower complete remission (CR) rate (18/35, 51%) than IgR-negative patients (85/120, 71%; P=0.042), and a significantly poorer overall survival (OAS) at 5 years (25 vs 66%; P<0.001). There was a significant difference in the estimated OAS at 5 years between patients with negative BM histology and negative PCR results (66%), patients with negative BM histology but positive IgR (37%), and patients with positive BM histology (12%). Our results indicate that molecular methods improve the accuracy of staging in patients with DLBCL and define a group of patients with normal bone marrow histology who have a significantly poorer OAS due to molecular detection of PB/BM involvement.

Coexistence of chronic lymphocytic leukemia and essential thrombocythemia

The association of chronic lymphocytic leukemia (CLL) with essential thrombocythemia (ET) is an extremely rare event and until now 3 patients with such coexistence have been reported in the literature. We report a 77-year-old white woman in whom these two disorders were diagnosed concomitantly on the basis of peripheral blood count and cytology, bone marrow cytology and histology, immunophenotyping, as well as exclusion criteria. The diagnosis of ET was also supported by spontaneous in-vitro erythroid colony growth and by evaluation of thrombopoietin (TPO) serum level. Interphase FISH analysis allowed to detect 13q14.3 deletion in 98% of lymphocytes nuclei. In contrast this aberration was not observed in the megakaryocytes. The results of PCR analysis of IgG gene rearrangement showed distinct bands characteristic for monoclonal lymphoid population in bone marrow, peripheral blood and inguinal lymph node. The patient was started on hydroxyurea 1 g/day and normalization of the platelet count was achieved. Possible etiopathogenic relationships between both disorders and differential diagnosis of ET and reactive thrombocytosis (RT) are discussed.

Hodgkin's type of Richter's syndrome in familial chronic lymphocytic leukemia treated with cladribine and cyclophosphamide

Second malignancies are frequent complications in patients with chronic lymphocytic leukemia (CLL). Hodgkin's disease (HD) has been observed in approximately 0.5% of the patients with CLL and is known as Hodgkin's type Richter's syndrome (H-RS). We present a 64-year-old male patient with a familial history of CLL who developed H-RS in abdominal lymph nodes 6 years after CLL diagnosis and 18 months after treatment with cladribine (2-CdA) and cyclophosphamide. HD was diagnosed by fine needle aspiration. The disease was refractory to treatment with two courses of CHOP and three courses of ABVD chemotherapy. In the current literature we found case reports of only 6 patients with H-RS who were treated with fludarabine (FA) before transformation, and, to our knowledge the presented patient is the first to develop H-RS after treatment with 2-CdA combined with cyclophosphamide. He is also the first published patient with familial CLL in whom this complication developed.

Langerhans cell histiocytosis in a patient with systemic lupus erythematosus: a clonal disease responding to treatment with cladribine, and cyclophosphamide

Langerhans cell histiocytosis (LCH) is a rare neoplastic disease of specific dendritic cells which belong to the monocyte-macrophage system. The association of LCH with autoimmune disease is extremely rare and to our knowledge its coexistence with systemic lupus erythematosus (SLE) has not been described so far. We report a case of LCH affecting liver, spleen and abdomen lymph nodes, which developed in an adult female six years after diagnosis of SLE treated for a long time with prednisone. Histology showed infiltration of characteristic Langerhans cells with folded, grooved or lobulated nuclei with fine chromatin. In the background there were eosinophils, lymphocytes and CD-68-positive histiocytes. The neoplastic cells were S100p-immunopositive, but stained negatively for CD1a--probably as the result of overfixation of consulted material. CD-68 was present mostly in macrophages. Ultrastructurally, the tumour cells presented structures consistent with Birbeck granules. Clonal origin of neoplastic cells was shown using the HUMARA-PCR assay. The disease was refractory to treatment with high doses of prednisone and vincristine but complete response was achieved after treatment with caldribine combined with cyclophosphamide.

Successful treatment of leukaemia cutis with cladribine in a patient with B-cell chronic lymphocytic leukaemia

Cutaneous presentation of B-cell chronic lymphocytic leukaemia (B-CLL) is uncommon, and the influence of skin changes on B-CLL prognosis is unclear. We report a patient with B-CLL Rai II, with multiple nodular skin infiltrations on the trunk, upper arms and thighs as well as constitutional symptoms, who was successfully treated with cladribine. The peripheral blood (PB) lymphocytes were CD19, CD20, CD23 and CD5 positive, which confirmed the diagnosis of B-CLL. Skin biopsy of one of the lesions showed an intense infiltrate composed of small lymphocytes with no epidermotropism. These cells also showed the expression of CD19, CD20, CD23 and CD5 antigens similar to those presented on PB lymphocytes. Polymerase chain reaction performed on bone marrow lymphocytes and a lesional skin biopsy using consensus primers for immunoglobulin heavy-chain genes also showed the same monoclonal population of B lymphocytes both in the bone marrow and in the skin. The patient received four courses of cladribine 0.12 mg kg-1 daily as a 2-h infusion for five consecutive days. The courses were repeated at monthly intervals. The lymphocytosis gradually decreased and the PB count normalized after three courses. At the same time, a significant decrease in the cutaneous symptoms was observed. The patient became free of skin tumours after the fourth course of cladribine; only slight discoloration at the previous sites of cutaneous infiltration remained. There was no relapse of leukaemia cutis during a further 7 months of observation.

Richter's syndrome following cladribine therapy for chronic lymphocytic leukemia first manifested as pathologic fracture of the femur

Richter's syndrome (RS) refers to the development of aggressive non-Hodgkin's lymphoma (NHL) during the course of chronic lymphocytic leukaemia (CCL). It occurs in approximately 3% of patients with CLL. The isolated form of this complication in bone is extremely rare and, so far, has not been described in a patient treated with cladribine (2-CdA). We report a case of CLL treated successfully with 2-CdA, where isolated diffuse large B-cell lymphoma (LBCL) developed 2 years after the diagnosis of CLL Rai II and one year after the completion of 2-CdA treatment. RS was first manifested as a pathologic fracture of the left femur. The LBCL was clonally distinct from the original CLL cells. The patient was successfully treated with CHOP and radiotherapy and obtained complete response of the LBCL.

Quantitation of minimal disease levels in chronic lymphocytic leukemia using a sensitive flow cytometric assay improves the prediction of outcome and can be used to optimize therapy

Previous studies have suggested that the level of residual disease at the end of therapy predicts outcome in chronic lymphocytic leukemia (CLL). However, available methods for detecting CLL cells are either insensitive or not routinely applicable. A flow cytometric assay was developed that can differentiate CLL cells from normal B cells on the basis of their CD19/CD5/CD20/CD79b expression. The assay is rapid and can detect one CLL cell in 10(4) to 10(5) leukocytes in all patients. We have compared this assay to conventional assessment in 104 patients treated with CAMPATH-1H and/or autologous transplant. During CAMPATH-1H therapy, circulating CLL cells were rapidly depleted in responding patients, but remained detectable in nonresponders. Patients with more than 0.01 x 10(9)/L circulating CLL cells always had significant (> 5%) marrow disease, and blood monitoring could be used to time marrow assessments. In 25 out of 104 patients achieving complete remission by National Cancer Institute (NCI) criteria, the detection of residual bone marrow disease at more than 0.05% of leukocytes in 6 out of 25 patients predicted significantly poorer event-free (P =.0001) and overall survival (P =.007). CLL cells are detectable at a median of 15.8 months (range, 5.5-41.8) posttreatment in 9 out of 18 evaluable patients with less than 0.05% CLL cells at end of treatment. All patients with detectable disease have progressively increasing disease levels on follow-up. The use of sensitive techniques, such as the flow assay described here, allow accurate quantitation of disease levels and provide an accurate method for guiding therapy and predicting outcome. These results suggest that the eradication of detectable disease may lead to improved survival and should be tested in future studies.

Low-grade non-Hodgkin's lymphoma in a patient with systemic lupus erythematosus

Coexistence of systemic lupus erythematosus (SLE) with low-grade non-Hodgkin's lymphoma (LGNHL) has been described occasionally in the literature with the potential pathogenetic role of monoclonal B CD5+/CD19+ cells. We report a case of LGNHL which developed 18 months after diagnosis of SLE. The monoclonal population of lymphocytes in the peripheral blood and bone marrow was CD5/CD19 negative but CD19/CD22 positive. The SLE responded well to treatment with prednisone and the course of the LGNHL was stable and cytotoxic treatment was not required.

Functional B-cell response in intrahepatic lymphoid follicles in chronic hepatitis C

Intrahepatic lymphoid follicle (ILF) formation is one of the most characteristic and commonly observed histological features in patients with chronic hepatitis C. However, little is known regarding whether follicles in the liver belong to functional lymphoid tissues, where B cells are activated, differentiated, and proliferated, or if the lymphocytes are merely infiltrated after recruitment from the secondary lymphoid organs. To ascertain this possibility, we examined the expression of markers for B-cell activation, differentiation, and proliferation in ILFs in patients with chronic hepatitis C using surgically resected specimens, and compared them with specimens of perihepatic lymph nodes by an immunohistochemical technique. Germinal center (GC) formation in the ILFs was frequently found in HCV-positive cases. The distribution of immunoglobulin M (IgM)-, IgD-, and IgG-positive cells and the expression patterns of Ki-67, CD23, or bcl-2 and bcl-6 gene products in the follicles with GC formation in the liver of patients with chronic hepatitis C were similar to those of lymph nodes, indicating that B cells are activated, proliferated, and differentiated in the ILFs with GC formation in patients with chronic hepatitis C. Oligoclonal expansion of B cells in the livers with ILFs was confirmed by an analysis of immunoglobulin heavy chain (IgH) gene rearrangement determined by polymerase chain reaction (PCR). These data strongly suggest that ILFs with GC formation, which are frequently found in patients with chronic hepatitis C, may functionally be the same as those found in lymph nodes with respect to B-cell expansion and maturation.

Combined polymerase chain reaction approach for clonality detection in lymphoid neoplasms

The present study analyzes the efficiency of a combination of four immunoglobulin heavy chain (IgH) gene polymerase chain reaction (PCR) primer systems and a multiplex T-cell receptor gamma chain (TRG) gene PCR for detection of clonality in 409 samples (234 paraffin sections, 175 bone marrow aspirates) of different lymphomas. Using the four IgH PCR systems together, clonality was detected in all samples of B-cell chronic lymphocytic leukemias, hairy cell leukemias, common acute lymphoblastic leukemias, and Burkitt-like B-cell lymphomas. Clonality was detected in all bone marrow aspirates with lymphoplasmacytoid immunocytoma, mantle cell lymphoma, marginal zone B-cell lymphoma, and unclassifiable low-grade B-cell lymphomas. The combined IgH gene PCR approach allowed clonality detection in 78.2% of myelomas, 75% of Burkitt lymphomas, 74.4% of diffuse large B-cell lymphomas, 68.7% of follicular center lymphomas, 50% of posttransplant lymphomas, 28.6% of anaplastic large cell lymphomas, 29% of T-cell lymphomas, and 18.8% of Hodgkin diseases. The combination of the four IgH gene primer systems with the multiplex TRG gene PCR allowed detection of clonality in 84.2% of B-cell neoplasms, 92.1% of T-cell non-Hodgkin lymphomas, and 18.8% of Hodgkin diseases, which was much more efficient than single PCR protocols.

Human leukotriene B4 omega-hydroxylase (CYP4F3) gene: molecular cloning and chromosomal localization

Leukotriene B4 (LTB4) omega-hydroxylase catalyzes the conversion of LTB4 into a biologically less active product, 20-hydroxy-LTB4. In a preceding paper (Kikuta et al., 1993), we showed human polymorphonuclear leukocyte (PMN) LTB4 omega-hydroxylase to be a novel form of cytochrome P450, designated CYP4F3, on the basis of its cDNA cloning and expression in yeast cells. Here, we have isolated the gene encoding CYP4F3 and determined its genomic organization and chromosomal localization. The CYP4F3 gene contained 13 exons and spanned approximately 22.2 kb. The cDNA of CYP4F3 contained 5050 nucleotides excluding the poly(A) tail. The translation initiation codon (ATG) was present in exon II. Primer extension and S1 mapping analyses indicated that the transcription initiation site is 49 nucleotides upstream from the 3' end of exon I, and no other initiation sites were detected. A TATA-box-like sequence (TACAT) and 120-b GC-rich sequence were observed just before transcription initiation site. Several putative regulating elements recognized by the GATA family, MZF-1, CACCC binding protein, and C/EBP, were identified in its 5' flanking region. Genomic DNA screening for CYP4F3 and Southern blot analysis suggested the existence of other CYP4F genes in addition to CYP4F3 and CYP4F2 in the human genome. Fluorescence in situ hybridization demonstrated that the CYP4F3 gene is located at 19p13.2.

Application of polymerase chain reaction to detect rearrangement of immunoglobulin heavy chain genes in lymphoproliferative disease

As part of our routine work-up in the diagnosis of lymphoproliferative disease, we used a rapid polymerase chain reaction (PCR) assay to amplify the DNA fragments of the framework 3 (FR3) region of the immunoglobulin heavy (IgH) chain genes. The assay does not involve hybridization, nested priming, or sequencing of the amplified PCR product. It was performed on 66 specimens of B-cell lymphoproliferative disease, including acute lymphoblastic leukemia, chronic lymphocytic leukemia, multiple myeloma, hairy cell leukemia and follicular lymphoma. Twenty-six specimens of negative controls, including acute myeloid leukemia, chronic myeloid leukemia in myeloid transformation and idiopathic thrombocytopenic purpura, were also analyzed. The assay was performed with 77% sensitivity and 100% specificity. The standard IgH chain gene rearrangement by Southern blot analysis is reserved for the remaining negative cases if clinically indicated.

B-cell gene rearrangement in benign and malignant lymphoid proliferations of mucosa-associated lymphoid tissue and lymph nodes

The polymerase chain reaction (PCR) with polyacrylamide gel electrophoresis was used to study patterns of immunoglobulin heavy chain (IgH) gene rearrangement (GR) in formalin-fixed, paraffin-embedded specimens of lymphomas and reactive conditions of mucosa-associated lymphoid tissue (MALT) and lymph node. DNA amplification was performed directly on sections obtained from paraffin blocks. Five patterns of PCR products were observed: a single band, two or more discrete bands, smearing, a single band overlying a smear, and two or more bands over a smear. A pure polyclonal pattern (smear) was observed in all of the reactive lymph nodes but in only 15% of cases of Helicobacter pylori (HP) gastritis with lymphoid hyperplasia, 25% of cases of HP gastritis without lymphoid hyperplasia, and 37% of colonic specimens of various types. Patterns consisting of multiple bands with or without background smearing were common in gastritis, colitis, and gastric lymphomas. Single bands or dominant bands were present in all lymph node and salivary gland lymphomas, 12 of 14 cases of gastric lymphoma, and 17 of 20 cases of HP gastritis with lymphoid hyperplasia. These bands were reproducible in deeper sections from the same paraffin block or similar areas sampled in different blocks in all of the lymph node and salivary gland lymphomas, 11 of 12 gastric lymphomas, but only 1 of 17 cases of HP gastritis with lymphoid hyperplasia. Bands were also found in 3 of 20 cases of HP gastritis without lymphoid hyperplasia and 17 of 38 colonic specimens, but these were not reproducible. The complexity of patterns of IgH GR in acquired MALT compared with lymph nodes may be the result of a relative paucity of B-cell clones or preferential proliferation of B-cell clones with a limited area of distribution.

Molecular genetics and lymphoproliferative disorders

Clonality of T- and B-cell lymphoproliferative disorders can be determined by gene rearrangement studies when morphology and surface immunostaining are nondiagnostic. TcR and lg gene rearrangements have been demonstrated in many different hematologic disorders and TcR gene rearrangement has been particularly useful in the diagnosis of patients with CD8 large granular lymphocyte leukemias. TcR gene rearrangement may also be useful to distinguish Hodgkin's disease from T-cell non-Hodgkin's lymphoma. Gene rearrangement is usually performed by Southern analysis, and it is beneficial to run multiple enzyme-probe combinations to maximize the detection of clonal rearrangements. More recently, several laboratories have begun to use polymerase chain reaction (PCR) for gene rearrangement analysis. PCR offers an improved turnaround time, eliminates partial digestion artifacts, and allows for the use of paraffin embedded material. In addition to rearrangements of the TcR and lg genes, analysis of alterations in other genes such as bcl-1, bcl-2, bcl-6, and c-myc are also useful as clonal markers and aid in the classification of lymphomas.

The usefulness of a rapid PCR methodology to detect rearranged Ig heavy chain genes in lymphoproliferative disease in a diagnostic setting

Polymerase chain reaction (PCR) was used to amplify the DNA fragments of the framework 3 region (FR3) of the immunoglobulin heavy (IgH) chain genes, from the tissue of 66 patients with B-lymphoproliferative diseases and 74 patients with other malignant diseases, reactive or normal tissue. The assay performed with 77% sensitivity, 100% specificity and 89% efficacy. In addition, the PCR assay cost less than 25% of the cost performing Southern blot analysis of tumor DNA, which has been the test performed to date, and had a turn around time of 24 hrs rather than the 7-14 days required to obtain a result from Southern blot analysis. These results suggest that PCR analysis of B-cell lymphoproliferative disease is superior to Southern blot analysis, in the setting of a diagnostic laboratory.

Optimal primer selection for clonality assessment by polymerase chain reaction analysis: I. Low grade B-cell lymphoproliferative disorders of nonfollicular center cell type

Recent polymerase chain reaction (PCR)-based studies focused on the detection of immunoglobulin heavy chain gene (IgH) rearrangements have suggested that clonal populations may be amplified more easily from certain categories of B-cell neoplasia than others and that primer makeup can be a critical factor in successful amplification. However, these particular reports contained relatively few low grade B-cell lymphoproliferative disorders of nonfollicular center cell type (LG-BLPD) and used only a limited panel of available primer sets for PCR amplification of monoclonal B-cell populations. To address this issue more extensively we evaluated 156 samples of LG-BLPD by the PCR to determine optimal primer selection in this setting. All cases were classified according to standard morphological and immunophenotypic criteria, with monoclonality documented by Ig light chain restriction analysis. The LG-BLPD included 33 cases of chronic lymphocytic leukemia (CLL), 57 cases of small lymphocytic lymphoma (SLL), 10 cases of atypical CLL, 32 cases of mantle cell lymphoma (MCL), 17 plasma cell neoplasms (PCNs), and seven cases of hairy cell leukemia (HCL). All primer sets included a 3' IgH joining region consensus primer, whereas the 5' IgH variable region (VH) primer was different in each set. The first-line panel included the following: Set 1, VH-framework III consensus primer, and Set 2, seven separate VH-framework I family-specific primers. A reserve panel of alternate VH consensus primers directed at framework II or III regions was used only when Set 1 showed no evidence of B-cell monoclonality.(ABSTRACT TRUNCATED AT 250 WORDS)