Molecular diagnosis of leukemia and lymphoma]

Diagnosis of leukemia and lymphoma has been made by morphological, cytochemical, and immunophenotypical methods. Recently molecular biological approaches have been introduced to clarify the cellular lineage of the tumor cells and to demonstrate the monoclonality. Southern blot analysis using immunoglobulin (Ig) and T cell receptor (TcR) genes revealed the presence of monoclonal components in some cases of angioimmunoblastic lymphadenopathy (AILD), in which demonstration of monoclonality was difficult by conventional methods. In preB-ALL, many cases had rearranged IgH and TcR genes simultaneously. These "dual genotype" cases were found to be of accidental involvement of TcR gene in the process of making effective IgH gene rearrangements by the precise analysis of rearranged IgH gene structures. The rearranged TcR gene which was detected in initial lymphoblastic lymphoma cells, was observed in relapsed blasts after lineage conversion to myeloid leukemia, which indicates the same clonal origin. Diagnosis and detection of minimal residual disease by the polymerase chain reaction (PCR) are now recognized as sensitive methods. PCR using oligonucleotides common to each VH and JH gene detects the rearranged IgH gene sensitively. PCR using primers located on the translocation boundary, such as bcr and abl in CML, is very useful in the diagnosis and pursuit of the disease course. PCR study also can be applied to the detection of alteration of some particular genes such as tumor suppressor genes.     

Improved PCR method for detecting monoclonal immunoglobulin heavy chain rearrangement in B cell neoplasms.

AIMS: To develop a simple, optimised, polymerase chain reaction (PCR) based method for detecting the rearranged immunoglobulin heavy chain (IgH). METHODS: Using as primers oligonucleotides (Fr2A, Fr2B) homologous to the conserved sequences to the framework II region and the joining (JH) region, 25 patients with B cell lymphoproliferative disorders, previously characterised by Southern blotting, and three patients with light chain myeloma were studied. RESULTS: The PCR product from a polyclonal B cell population showed a broad band when analysed on a 3% agarose gel; DNA from B cell lines and B lymphoproliferative disorders showed a discrete band. Specificity of the amplification was confirmed by cloning and sequencing the amplified product as well as by Southern blotting with an internal probe homologous to the framework 3 region. Primers Fr2A and Fr2B detected monoclonality in three patients with light chain myeloma, while primers directed against the FrIII region showed a polyclonal response. CONCLUSIONS: Deletions and extensive somatic mutations within the FrIII region may give false negative results with primers homologous to the region. A PCR using the method described, with a repertoire of primers homologous to the FrII and FrIII regions, will therefore increase the frequency of detection of monoclonality.     

Identification of monoclonal B-cell populations by rapid cycle polymerase chain reaction. A practical screening method for the detection of immunoglobulin gene rearrangements.

Alternatives to Southern blot hybridization for gene rearrangement analysis are being studied because of the time, labor, cost, and radioisotopes required for this technique. We have utilized a rapid, hot air, thermocycling polymerase chain reaction (PCR) system to examine various lymphoproliferative disorders for immunoglobulin heavy chain (IgH) gene rearrangements. This unique system amplifies DNA from 10 microliters samples placed in glass capillary tubes, over a total cycle time of about 30 minutes. Amplified bands are easily visualized on ethidium bromide-stained agarose gels. Forty-one monoclonal B-cell proliferations, 27 reactive lymphoid hyperplasias, 17 T-cell lymphomas and 3 cases of Hodgkin's disease were studied. All 88 cases were fully characterized by morphologic, immunophenotypic, and genotypic (Southern blot) analyses. Each case was separately evaluated by PCR with two primer pairs: 1) IgH variable region (VH) and IgH joining region (JH) and 2) bcl-2 and JH. Thirty-four of 41 monoclonal B-cell proliferations revealed a distinct band (within an expected base pair range) with 1 or both primer combinations supporting B-cell monoclonality; the other 7 cases were considered false negatives. The 47 entities without IgH gene rearrangements detectable by Southern analysis demonstrated no amplified product or a smear of amplified DNA with no distinct band. The overall specificity of PCR was 100%, and the sensitivity was 83% when directly compared with Southern blot analysis. Although its sensitivity is currently less than optimal, PCR is a rapid and practical screening method for the detection of IgH gene rearrangements. If a positive result is obtained no further analysis is required; however, if there is a negative result, standard Southern blot analysis should be performed to definitively exclude the presence of a monoclonal B-cell population in the sample.     

The polymerase chain reaction in the demonstration of monoclonality in T cell lymphomas.

AIMS--To evaluate polymerase chain reaction (PCR) amplification of T cell receptor (TCR) beta and gamma chain genes as a means of demonstrating monoclonality in T cell lymphomas using histological samples; to compare the performance of PCR with Southern blot analysis. METHODS--TCR-beta, TCR-gamma and immunoglobulin heavy chain (IGH) genes were analysed using PCR in 55 cases of T cell lymphoma (28 frozen tissue and 27 paraffin wax embedded samples), diagnosed using morphological and immunohistochemical criteria. The 28 frozen samples were subjected to Southern blot analysis using TCR-beta, TCR-gamma and IGH gene probes. Twenty five B cell lymphomas and 21 non-neoplastic lymphoid tissue samples were used as controls. RESULTS--Using TCR-beta PCR, monoclonality was detected in 24 (44%) of 55 T cell lymphomas compared with 43 (78%) of 55 using TCR-gamma PCR and in 82% with both techniques. Five (9%) of 55 T cell lymphomas were IGH PCR positive. None of the non-neoplastic lymphoid control samples were PCR positive. All B cell lymphomas showed a polyclonal pattern with TCR-beta PCR while a single B cell lymphoma was positive using TCR-gamma primers. With TCR-beta PCR, a monoclonal result was seen in 12 (43%) of 28 frozen samples of T cell lymphoma, compared with 23 (82%) of 28 using Southern blot analysis. With TCR-gamma PCR, 19 (68%) of 28 frozen tissue samples were positive, compared with 26 (93%) of 28 using Southern blot analysis. A single case showed IGH rearrangement by Southern blot analysis. CONCLUSION--TCR-gamma PCR should be the method of choice for analysis of clonality in paraffin wax embedded sections of lymphoproliferative lesions, as TCR-beta PCR has a high false negative rate. Southern blot analysis remains the most successful technique when sufficient fresh tissue samples and resources are available.     

VJ REARRANGEMENTS OF THE TCRγ LOCUS IN PERIPHERAL T-CELL LYMPHOMAS: ANALYSIS BY POLYMERASE CHAIN REACTION AND DENATURING GRADIENT GEL ELECTROPHORESIS

Using Southern blotting for the diagnosis of clonality in peripheral T-cell lymphomas (PTCLs), analysis of the T-cell receptor (TCR) γ gene rearrangement was shown to be more informative than that of the TCR β gene rearrangement. In order to amplify every VJγ rearrangement, a polymerase chain reaction (PCR) procedure using newly designed GC-clamp primers has been developed. All primers can be mixed in a single multiplex PCR. PCR products are analysed by denaturing gradient gel electrophoresis (DGGE), providing tumour-specific imprints inasmuch as the procedure characterizes N sequence polymorphism at the VJ junctions. In a series of 30 PTCL cases, the PCR procedure demonstrated 27 cases to be clonally rearranged and failed in three cases. PCR was more accurate than Southern blotting, showing 47 rearranged γ alleles, four of which were undetectable on the Southern blot. When lymphomas were studied at different sites and at relapse, the DGGE pattern remained unchanged. In PTCL, the proposed PCR is helpful for the diagnosis and staging of the disease and should improve the follow-up monitoring. The undetectability of clonal rearrangements in a few cases is discussed in the light of concepts of lymphomagenesis and T-cell differentiation.     

Primary B cell gastric lymphoma. A genotypic analysis.

A series of cases of gastric lymphoproliferative disease exhibiting the features of pseudolymphoma, frank lymphoma, or both was investigated immunohistochemically and genotypically for evidence of B cell clonality. Immunoperoxidase studies on frozen and paraffin sections showed that all cases clearly exhibited immunoglobulin light chain restriction (eight cases kappa, six cases lambda). Southern blotting using JH, Ck, and Cl probes to detect clonally rearranged gene fragments confirmed monoclonality in each case, and the immunohistochemical and genotypic data were in agreement in all cases except one (1 light chain restriction/k gene rearrangement). The study confirmed that light chain restriction in gastric lymphoid infiltrates is synonymous with monoclonality ant there is a histologic continuum between low grade B cell gastric lymphoma with features of pseudolymphoma and high grade B cell lymphoma. The authors believe that histologic and immunohistochemical features such as light chain restriction clearly discriminate reactive and neoplastic gastric lymphoid infiltration. Therefore, light chain-restricted lymphoid proliferation, previously termed pseudolymphoma is, in fact, an early stage of frank lymphoma, which obviates the need to use the term pseudolymphoma.     

Immunohistochemistry and gene rearrangement studies in the diagnosis of malignant lymphomas: a comparison of 152 cases.

One hundred fifty-two cases (155 specimens) of lymphoproliferative disorders were studied by immunohistochemistry and gene rearrangement analysis. Ninety-five of 96 B-cell lymphomas (99%) showed genotypic B-cell monoclonality. Of these, five cases had rearranged T-cell receptor (TCR) beta chain gene in addition to immunoglobulin heavy chain (IgH) and kappa light chain (Ig-K), one case had rearranged IgH and TCR-gamma chain but not Ig-K or TCR-beta, and two cases had only Ig-K rearrangement. One exceptional case in the B-cell lymphoma group had unrearranged, germline genotypes. In contrast, only 10 of 19 (53%) phenotypic T-cell lymphomas had rearranged TCR-beta, eight with concurrent TCR-gamma rearrangement. Of the remaining nine cases, six had germline configuration, two had rearranged Ig-K only, and one had both IgH and Ig-K rearrangement. This last case was reclassified as T-cell predominant, B-cell lymphoma. Thirteen of 16 cases of Hodgkin's disease had germline configuration; three cases had rearranged IgH and Ig-K, of which two were lymphocyte predominant with light chain monoclonality and one was a recurrence. Among 21 reactive lesions, 17 had germline configuration and four had rearranged IgH and Ig-K genes. Of these four cases, two were orbital lesions, one was a partially involved lymph node, and one developed a nodular lymphoma 9 months later. Our results indicate that almost all B-cell lymphomas have IgH and/or Ig-K rearrangement. In contrast, peripheral T-cell lymphomas have greater genotypic heterogeneity, and germline patterns for TCR genes are not uncommon. Reactive lesions and Hodgkin's disease tend to retain germline configuration, and any exception is often associated with an unusual clinical setting and/or histology. Genotypic analysis is thus most indicated in B-cell lymphomas with equivocal immunohistochemistry findings, T-cell lymphomas, and atypical cases of Hodgkin's disease and reactive lesions.     

Detection of clonal immunoglobulin gene rearrangements by polymerase chain reaction amplification and single-strand conformational polymorphism analysis.

Analysis of immunoglobulin gene rearrangements by Southern blotting is a sensitive and specific method for detecting B cell malignancies but requires a relatively large amount of intact DNA. It cannot be utilized in many cases where only a small amount of tissue is available or where the tissue has been fixed. This report demonstrates that polymerase chain reaction (PCR) amplification in conjunction with single-strand conformational polymorphism (SSCP) analysis can be utilized to detect clonal immunoglobulin heavy chain (IgH) gene rearrangements. IgH gene rearrangements from a series of frozen or formalin-fixed B cell malignancies were PCR-amplified using oligonucleotide primers, based upon consensus sequences in the IgH variable and joining regions. Analysis of the single-stranded PCR products on nondenaturing polyacrylamide gels revealed discrete SSCPs corresponding to the malignant B cells. These SSCPs were detectable when the malignant cells represented as few as 0.2% of the total mononuclear cells in peripheral blood. PCR amplification in conjunction with SSCP analysis thus provides a sensitive and specific method to detect clonal IgH rearrangements from minute amounts of fresh, frozen, or fixed tissue.     

Detection of concurrent/recurrent non-Hodgkin's lymphoma in effusions by PCR

A subset of patients with non-Hodgkin's lymphoma (NHL), present with or subsequently develop lymphocytic effusions. Differential diagnosis between reactive lymphocytosis and recurrent low-grade NHL is difficult by cytology alone. We studied the use of polymerase chain reaction (PCR)-based techniques to detect concurrent/recurrent NHL. Both primary tumors and atypical lymphocytic effusions of 12 low-grade B-NHL patients and 4 T-NHL patients were studied. Six pleural effusions (reactive/carcinomatous), in patients with no history of NHL, were included. Samples were amplified by PCR, using Fr3, Fr2, LJH, and VLJH primers specific for the immunoglobulin heavy chain (IgH) gene and Vgamma-8, Vgamma9, Vgamma10, Vgamma11 and Jgamma1/Jgamma2 consensus primers specific for the T-cell receptor gamma (TCR-gamma) gene. IgH gene PCR products were analyzed by polyacrylamide gel electrophoresis (PAGE). TCR-gamma gene PCR products were analyzed using a novel nonradioactive single-strand conformational polymorphism (SSCP) procedure. IgH gene rearrangement analysis demonstrated monoclonality in 11/12 primary low-grade B-NHLs. Identical monoclonal bands were found in both primary tumor and effusion in 9 patients. TCR-gamma gene rearrangement analysis demonstrated monoclonality in 4 of 4 primary T-NHLs. Identical monoclonal banded patterns were found in both primary tumor and effusion in 3 patients. Our results strongly support the diagnosis of concurrent/recurrent NHL in 13 of 16 (81%) cases of atypical lymphocytic effusions. IgH/PAGE and TCR-gamma/SSCP analyses are useful tools in the diagnoses of lymphocytic effusions in patients with NHL.     

Sensitivity of PCR in detecting monoclonal B cell proliferations.

AIMS--To evaluate the rapid detection of various forms of monoclonal B cell proliferations by using the polymerase chain reaction (PCR) to identify clonal immunoglobulin heavy chain genomic rearrangements. METHODS--Thirty four B cell lymphomas defined by morphology, immunophenotyping, and positive immunoglobulin heavy chain gene rearrangements detected by Southern blot analysis were examined. An additional 22 cases representing miscellaneous lymphoproliferative and non-lymphoproliferative disorders were also studied. RESULTS--Monoclonal rearrangements were identified in 19 (56%) cases of B cell lymphoma. The method was less sensitive in the detection of follicular centre cell lymphomas (15 of 28, or 54%) than non-follicular centre cell lesions (four of six, or 67%). Monoclonal rearrangement was not identified in 19 control cases, including T cell lymphomas, Hodgkin's disease, reactive lymphadenopathy and metastatic carcinoma. Three cases showed positive immunoglobulin gene rearrangement by PCR but were negative on Southern blotting. Two of these cases had definite clinical, morphological, and immunophenotypic evidence of monoclonal B cell proliferation suggesting that PCR could, on occasion, pick up cases missed by Southern blotting and that the two methods are complementary in clonal lymphoproliferative disease diagnosis. The third case represented a "false positive" PCR reaction involving a colonic adenocarcinoma. CONCLUSIONS--PCR analysis, using the primer sequences outlined in this study, will detect about 55% of clonal lymphoproliferative proliferations with increased sensitivity for non-follicular centre cell lesions. With these levels of detection in mind, this testing strategy can still be especially useful in cases which prove diagnostically problematic with standard morphological and immunophenotypic analysis, and in instances where the quantity and type of diagnostic material is limiting (needle aspirates and cellular fluids).     

血液系统肿瘤患者外周血细胞IgH基因和TCRγ基因的检测及意义

检测各种血液系统肿瘤患者外周血细胞免疫球蛋白重链基因 (IgH )和T细胞受体γ基因 (TCRγ )克隆性重排并探讨其意义。通过多聚酶链式反应 (PCR )方法检测 32例非霍奇金淋巴瘤 (NHL )、 18例急性髓性白血病 (AML )、 2 4例多发性骨髓瘤 (MM )、 8例急性淋巴细胞白血病 (ALL )及 6例慢性淋巴细胞白血病 (CLL )患者外周血细胞IgH及TCRγ克隆性基因重排。结果表明 ,NHL、AML、MM、ALL及CLL患者中IgH克隆性重排率分别为 37 5 0 %、 2 2 2 2 %、 83 33%、 12 5 0 %和 16 6 7% ;TCRγ基因克隆性重排率分别为 6 2 5 0 %、 5 0 0 0 %、 5 4 17%、 5 0 0 0 %及 5 0 0 0 %。在B型、T型NHL中 ,IgH克隆性重排率分别为 31 5 8%及 6 6 6 7% ;TCRγ克隆性重排率分别为 47 37%及 6 6 6 7%。AML中IgH克隆性重排阳性者的初治完全缓解率(CR ) (5 0 0 0 % )与IgH重排阴性的初治CR率 (5 0 0 0 % )无显著差异 (P >0 0 5 )。TCRγ克隆性重排阳性者与阴性者的初治CR率 (均为 44 44 % )亦无显著差异 (P >0 0 5 )。IgH及TCRγ基因克隆性重排不具有细胞谱系的特异性 ,但通过检测外周血IgH、TCRγ克隆性基因重排对NHL有辅助诊断意义 ,并且可作为监测微小残留病壮 (MRD )的手段。     

Molecular analysis of gastric washings in the diagnosis and monitoring of gastric lymphomas

The monitoring of gastric lymphomas is often hampered by the inherently limited sampling provided by small endoscopic biopsy specimens. To investigate the feasibility of using gastric washing fluid for monitoring patients with known gastric lymphoma and for diagnosing gastric involvement in patients with extranodal nongastric lymphoma, we collected 49 gastric washings from 39 patients (29 patients with gastric lymphoma and 10 patients with nongastric extranodal lymphoma). Collection was done at the time of follow-up biopsy and when no endoscopic abnormalities were found. DNA was extracted from the washing fluid and analyzed for clonal IgH gene rearrangement by Southern blotting (J6 probe) and/or polymerase chain reaction (PCR) (using VH-FR3 and JH primers). Forty-one of 49 samples (84%) yielded sufficient DNA for molecular analysis. Sixteen of 41 analyzable gastric washing samples (39%) failed Southern blot analysis due to degraded or insufficient DNA. Concordance between the results of Southern blot analysis of the washing and histology of the simultaneous biopsy specimen was found in 20 (80%) of the remaining 25 samples. The IgH PCR result was concordant with biopsy histology in 33 out of 41 washing samples (80%). The overall concordance between molecular clonality studies of washings (Southern blotting and/or PCR) and biopsy histology was 83% (34 of 41). Of the 7 (18%) discrepant specimens, 2 were diagnosed histologically as lymphoma, but the simultaneous washings were negative by molecular studies. Five biopsy specimens were histologically benign, but the corresponding washings demonstrated clonal IgH gene rearrangement (3 cases by PCR and 2 cases by Southern blotting). This study demonstrates the diagnostic utility of molecular clonality analysis of gastric washings.     

Detection of rearrangements of the BCL2 major breakpoint region in follicular lymphomas. Correlation of polymerase chain reaction results with Southern blot analysis.

The translocation t(14;18)(q32;q21) occurs in 70% of follicular lymphomas and places the BCL2 proto-oncogene, normally located at 18q21, under the control of the immunoglobulin heavy chain (IgH) gene at 14q32. Its detection by the polymerase chain reaction (PCR), made possible by the close clustering of most of the BCL2 breakpoints in the major breakpoint region (MBR) of the gene, has numerous clinical applications. Since the PCR covers shorter lengths of DNA than Southern blotting, PCR-based tests may be more susceptible to microheterogeneity in breakpoint location. There have been no published studies of the impact of breakpoint microheterogeneity on the detection rate of this translocation by PCR. We studied 30 follicular lymphomas with the t(14;18), in which a BCL2 MBR rearrangement had previously been demonstrated and mapped by conventional Southern blotting, by PCR with the commonly used IgH and BCL2 MBR primers. Twenty-five cases (83%) had a junction fragment demonstrable by PCR. All three cases in which the MBR rearrangement mapped outside of the 4.3-kb HindIII fragment containing the MBR, as determined by Southern blotting, were negative by PCR. In addition, two cases with rearrangements within the HindIII fragment were also negative. All negative results were repeated at least once and were confirmed to be true negatives by actin PCR. Our results suggest that negative PCR results in this setting are attributable to small variations in BCL2 MBR breakpoint location and cannot be interpreted without the corresponding conventional Southern blotting data. With this caveat in mind, PCR analysis for the t(14;18) remains an extremely useful technique, especially in the follow-up and monitoring for minimal residual disease in previously characterized cases of follicular lymphoma.     

Improvements to B cell clonality analysis using PCR amplification of immunoglobulin light chain genes.

AIMS: Clonality analysis using polymerase chain reaction (PCR) amplification of the immunoglobulin heavy chain (IgH) gene is an important aid to the diagnosis of B cell lymphoproliferative diseases. However, the method has a relatively high false negative rate. In an attempt to improve detection rates simple PCR strategies for clonality analysis of B cell populations using amplification of Ig light chain genes have been developed. METHODS: Novel PCR protocols, designed to amplify Ig kappa and Ig lambda light chain genes, were evaluated using high molecular weight DNA samples from 28 selected cases of B cell lymphoma with known light chain expression and 12 reactive lymphoid specimens. Products were run on 10% polyacrylamide minigels using heteroduplex analysis. Conventional IgH PCR analysis was also performed. Twelve randomly selected formalin fixed, paraffin wax processed samples from cases submitted for molecular genetic analysis were also studied. RESULTS: Polyclonal products were seen in all reactive lymphoid samples. Using Ig kappa PCR, 24 of 28 lymphomas, including four of five IgH negative cases, displayed monoclonal patterns. Using Ig lambda PCR, eight of 12 Ig lambda expressing tumours, including two of five IgH negative cases, showed monoclonal patterns. Standard IgH PCR demonstrated monoclonality in 23 of 28 B cell lymphomas. The detection rate was improved to 27 of 28 lymphomas using heavy and light chain PCR. Efficient amplification was achieved using paraffin wax processed samples, seven of which showed monoclonality compared with eight using IgH PCR. CONCLUSIONS: Ig light chain PCR, used in conjunction with heavy chain analysis, enables improved detection of B cell monoclonality using routine histological specimens and can provide additional clone specific markers for the study of the biology of B cell tumours.     

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. Overall, monoclonal B-cell populations were amplified in 153 of 156 (98%) neoplasms by the PCR; two PCNs and one plasmacytoid SLL were negative with all primer pairs. Higher amplification efficiency was obtained with Set 1 primers than Set 2 primers in the entire series (96% ν 84%) as well as within each subtype of LG-BLPD. In each diagnostic category monoclonal B-cell populations were detected by Set 1 in 96% or more of neoplasms, the only exception being plasma cell neoplasms where the monoclonality detection rate was 76% (ie, 13 of 17 cases). With the additional use of Set 2 and the reserve panel primer sets, 15 of 17 (88%) PCNs were shown to contain PCR-detectable monoclonal B-cell populations. Our data suggest that the vast majority of CLLs, SLLs, MCL, and HCL samples can be successfully genotyped by the PCR with a single primer set (Set 1). In contrast, plasma cell tumors and rare SLL samples appear to require more extensive analysis (ie, additional primer sets) to adequately assess B-cell clonality.     

Immunoglobulin heavy chain rearrangements in primary brain lymphomas. A study using PCR to amplify CDR-III

Primary brain lymphomas (PBLs) have only rarely been analysed for immunoglobulin heavy chain (IgH) rearrangements. In this study, DNA was extracted from paraffin blocks in 23 cases of PBL and examined for IgH rearrangements using the polymerase chain reaction (PCR) to amplify the complementarity-determining region III (CDR-III) of rearranged IgH genes. Fifteen of the cases were phenotyped on paraffin-embedded tissue using a pan-B and pan-T antibody (L26 and UCHL-1, respectively). The remaining eight cases were not phenotyped for lack of tissue. For comparison, we used DNA extracted from paraffin blocks of normal brain, lymph nodes with lymphoid hyperplasia, and non-lymphoid malignancies. PCR products were examined by polyacrylamide gel electrophoresis. Among the ten B-cell PBL; four had a pattern indicative of IgH rearrangement, one had a germline pattern, and five had no detectable PCR products. Among the five T-cell PBLs, one had a germline pattern and four had no detectable products. Among the eight untyped PBLs, two had IgH rearrangement, four had a germline pattern, and two gave no detectable products. DNA from non-lymphoid tissues gave a consistent germline pattern, while DNA from polyclonal lymphoid populations (lymph node) had a pattern of polyclonal IgH rearrangement. In a dilution study, a clonal rearrangement could be detected as long as the clone's DNA constituted at least 10 per cent of the total DNA. PCR to amplify CDR-III can be successfully applied to DNA extracted from paraffin blocks, and it detected a clonal rearrangement in 50 per cent of cases that gave a detectable pattern. This allows clonality analysis of tissue unsuitable for conventional Southern blot analysis. Furthermore, B-cell PBLs have IgH rearrangements similar to those of extracranial B-cell neoplasms.     

PCR analysis of immunoglobulin heavy chain (IgH) and TcR-gamma chain gene rearrangements in the diagnosis of lymphoproliferative disorders: results of a study of 525 cases.

This report summarizes a cumulative 4-year experience in polymerase chain reaction (PCR) analysis of immunoglobin heavy chain (IgH) and TcR-gamma chain gene rearrangements in 525 cases of lymphoproliferative disorders. Because the sensitivity of the PCR methodology was found to be tissue dependent, in the study of the presence of clonal cell population in tissues containing a small number of polyclonal lymphocytes, such as skin and gastrointestinal biopsy specimens, we used the multiple-PCR run approach. In this latter methodology, we repeat the PCR reaction from the same sample at least three times to confirm the reproducibility of the results. In the study of 273 cases of B- or T-cell lymphomas with characteristic immunomorphological and clinical features, a clonal IgH or TcR-gamma chain gene rearrangement was detected in approximately 80% of cases. A clonal rearrangement involving both IgH and TcR-gamma chain genes was found in 10% of cases of both B-cell and T-cell lymphomas. The study of 167 cases of nonneoplastic lymphoid tissue samples showed the presence of clonally rearranged cell populations for IgH or TcR-gamma genes in 3 and 9% of cases, respectively. We also applied PCR for the study of 85 cases of lymphoproliferations with no definite diagnosis (i.e., benign versus malignant) after immunomorphological analysis. In 65 cases (76%), the correlation of immunomorphological features with the presence (48 cases) or the absence (17 cases) of clonal lymphoid cell populations led to a definite diagnosis. In almost all these cases, the final diagnosis was found to be in agreement with the clinical course. In the 20 remaining cases (24%), no definite diagnosis could be made. We also assessed the value of PCR in detecting bcl-2/J(H) gene rearrangement as an additional clonal marker in the diagnosis of follicular lymphoma. Bcl-2/J(H) rearrangement and/or IgH gene rearrangement was found in approximately 85% (71/85) of follicular lymphoma cases studied.     

Application of PCR in the diagnosis of B-type non-Hodgkin's lymphomas in cytological specimens from fine-needle aspiration

The application of PCR to detect monoclonality at the immunoglobulin heavy chain gene locus in FNA cytologic specimens was evaluated. MATERIALS AND METHODS: Immunoglobulin heavy chain gene rearrangement analysis was performed by a nested PCR for the VDJ region on 27 lymph nodes FNA paraffin embedded by cell blocking technique specimens (1 suspicious of NOS lymphoma, 1 Hodgkin's disease, 6 B cell non Hodgkin's lymphomas, 10 reactive hyperplasias). RESULTS: A monoclonal band was seen in 13 of 17 suspicious or positive malignant cases. The other 4 specimens gave a policlonal pattern. Specimens from reactive lymph nodes produced policlonal bands in 8 cases, no product in 1 case and 1 specimen gave a monoclonal band. When needed, the results of PCR examinations were compared with the subsequent histologic evaluation of the same lymph-node. CONCLUSIONS: From our experience we can see that clonal analysis by PCR based IgH gene rearrangement analysis can be applied to FNA material and can be useful in diagnosis.     

IgH AND TcR-γ GENE REARRANGEMENTS IDENTIFIED IN HODGKIN'S DISEASE BY PCR DEMONSTRATE LACK OF CORRELATION BETWEEN GENOTYPE,PHENOTYPE, AND EPSTEIN–BARR VIRUS STATUS

Analysis of IgH and TcR-γ genes using consensus primers identifying junctional regions of rearranged genes by polymerase chain reaction (PCR) was performed on tissues involved by Hodgkin's disease (HD) in 90 cases and was correlated with the immunophenotype of Hodgkin and Reed–Sternberg (HRS) cells and the presence of Epstein–Barr virus (EBV) within these cells. Clonal IgH gene rearrangements were found in 1/5 cases of lymphocyte predominance (LP) subtype and none was positive for EBV. In 85 cases of classic HD, no IgH or TcR-γ gene rearrangements were found in 51 (60 per cent) cases. A similar percentage, but not the same cases, were of null (non-B, non-T) phenotype. Of 30 cases where a B phenotype was assigned to HRS cells, nine had IgH gene rearrangements, three had TcR-γ gene rearrangements, and two had both genes rearranged. None of the five cases assigned to T phenotype of HRS cells showed rearrangement of TcR-γ genes, but two cases showed rearranged IgH genes. Among 41 cases of null phenotype, ten had IgH gene rearrangements, five had TcR-γ gene rearrangements, and three cases had both genes rearranged. Whereas EBV was detectable in HRS cells in 17/43 classic HD cases of assigned B phenotype, EBV was also detectable in 2/5 cases of assigned T phenotype and in 21 cases with the null phenotype. Furthermore, there was no correlation of EBV with the presence or lack of IgH or TCR-γ gene rearrangements. Of the remainder, half (30 per cent) expressed antigens associated with lymphocytes without an appropriate genotype. The results confirm lymphocyte-lineage committed cells at the origin of HRS cells in 40 per cent of cases. Any hypothesis of a non-lymphocytic origin of HRS cells will require the inducibility of CD30 on candidate precursors and the methodology for probing genetic events in such cells to be addressed. © 1997 by John Wiley & Sons, Ltd.     

B细胞非霍奇金淋巴瘤IgH基因重排检测及凝胶扫描技术应用的初步研究

目的 采用凝胶扫描技术,力求对采用聚合酶链反应(PCR)检测非霍奇金淋巴瘤(NHL)抗原受体基因重排结果分析时建立量化标准,以利于临床医师应用时客观判断,并为其筛选随访病例提供依据。方法用PCR对96例B-NHL分别采用IgH FR3A及FR2A检测IgH基因克隆性重排。65例经IgH FR3APCR已证实为IgH基因克隆性重排B-NHL及8例良性病变淋巴组织和5例正常人外周血单核细胞,IgH FR3APcR产物8％变性聚丙烯酰胺凝胶电泳银染后图像行凝胶扫描,绘制曲线并计算h1／h2比值。结果(1)采用FR3A引物,克隆性IgH基因重排在96例B-NHL中检测率为68％,采用FR2A引物,检测率为61％,结合FR3A、FR2A引物,总检测率为83％。(2)凝胶扫描曲线示65例B-NHL的h1／h2均＞3,而5例正常人外周血单核细胞曲线均表现为钟型,8例良性病变淋巴组织h1／h2比值均＜1．5。结论非霍奇金淋巴瘤抗原受体基因重排检测的凝胶扫描分析曲线中,h1／h2峰高比值至少＞3可提示为IgH基因克隆性苇排,＜1．5可能提示IgH基因多克隆重排。比值介于1．5和3之间,提示有随访意义。联合FR3A,FR2A引物,可提高B-NHL IgH基因克隆性重排的检测率。