Clinical utility of heteroduplex analysis of TCR gamma gene rearrangements in the diagnosis of T-cell lymphoproliferative disorders

Utility of a Simple and Robust Flow Cytometry Assay for Rapid Clonality Testing in Mature Peripheral T-Cell Lymphomas

OBJECTIVES

Flow cytometry immunophenotyping is limited by poor resolution of T-cell clones. A newly described antibody was recently used to distinguish normal peripheral blood T cells from malignant T-cell clones. Here, we evaluate this antibody as a new diagnostic tool for detecting T-cell clonality in mature peripheral T-cell lymphomas.

METHODS

Immunostaining for the T-cell receptor β chain constant region 1 (TRBC1) along with routine T-cell markers was performed on 51 peripheral blood and two bone marrow samples submitted to the flow cytometry laboratory for suspected T-cell malignancy.

RESULTS

TRBC immunophenotyping identified malignant T-cell clones with 97% sensitivity and 91% specificity. Findings correlated with molecular T-cell clonality testing. In cases with equivocal molecular results, TRBC1 immunophenotyping provided additional diagnostic information.

CONCLUSIONS

TRBC1 flow cytometric immunophenotyping is a robust and inexpensive method for identifying T-cell clonality that could easily be incorporated into routine flow cytometric practice.

Concurrent administration of intravenous systemic and intravitreal methotrexate for intraocular lymphoma with central nervous system involvement

Intraocular lymphoma (IOL) is rare lymphoma that frequently infiltrates the central nervous system (CNS). An optimal treatment has not been established, and its prognosis is quite poor. We treated three IOL patients with CNS involvement by concurrent administration of intravenous and intravitreal methotrexate (MTX) injection. The intraocular lesion responded in all patients. One patient achieved complete response (CR), whereas the other 2 patients were in partial response for CNS lesion, added whole brain radiation and achieved CR. In 3 eyes of 2 patients, an intravitreal MTX injection (vMTX) was administered 2 h after a systemic MTX injection (sMTX) and the intravitreal MTX concentration was measured twice: 2 h after sMTX and 24 h after vMTX. The half-life of MTX in the vitreous fluid was estimated to be 12.4-21.5 h by assuming the first-order elimination kinetics. Although the concentration was still high 24 h after vMTX (69.94-82.89 muM), there were no ocular complications. The serum MTX concentration was not influenced by adding vMTX to sMTX. Grade 3 adverse event, leukocytopenia, was observed in only 1 patient. No grade 4 event was observed. Although further evaluation is required, concurrent sMTX and vMTX may be effective for IOL with CNS involvement.

Diagnosis of intraocular lymphoma by polymerase chain reaction analysis and cytokine profiling of the vitreous fluid

PURPOSE

To determine whether a diagnosis of intraocular lymphoma (IOL) can be made using a combination of polymerase chain reaction (PCR) analysis to detect gene rearrangement of immunoglobulin and cytokine concentrations in the vitreous fluid.

METHODS

Vitreous samples from 22 patients with clinically suspected IOL and ten control patients with acute retinal necrosis or cytomegalovirus retinitis were examined by PCR analysis and cytokine measurements. Genomic DNA was extracted from the cells in the vitreous, and the immunoglobulin heavy chain (IgH) gene was amplified by two PCR procedures: (1) microdissection and PCR to detect IgH gene rearrangement and (2) qualitative PCR to detect IgH VDJ gene rearrangement. The supernatants of the vitreous samples were used for enzyme-linked immunosorbent assay to determine interleukin (IL)-10 and IL-6 levels.

RESULTS

PCR examinations detected IgH rearrangement in the vitreous in 21 of the 22 IOL patients (95.5%) and in none of the ten control patients. Elevated IL-10 concentrations (>100 pg/ml) and the IL-10/IL-6 ratio (>1.0) were positive in 18 of the 22 IOL patients (81.8%), but negative in all of the control patients. Sensitivity, specificity, positive predictive value, and negative predictive value of PCR for the diagnosis of IOL were calculated to be 0.955, 1.000, 1.000, and 0.909, respectively, and those of the cytokine concentration assay to be 0.818, 1.000, 1.000, and 0.714, respectively. When both the intravitreal cytokine assay and PCR analysis of the vitreous samples are used, as well as diagnostic criteria of IOL defined as a positive outcome from one of the two assays together with clinical signs, the sensitivity and specificity of the criteria were 1.000.

CONCLUSIONS

A combination of PCR assay to detect gene rearrangement of IgH and cytokine profiling (IL-10 and IL-6) is extremely useful for the diagnosis of intraocular lymphoma.

A limited number of IgH-primers binding to framework region 1 is sufficient to detect the majority of mature small B-cell non-Hodgkin lymphomas on formalin-fixed paraffin-embedded tissue by PCR

IGH gene rearrangement analysis by PCR is the widely accepted tool to determine clonality of B-cell lymphoid proliferations on formalin-fixed, paraffin-embedded tissue, but the results are often unsatisfying in terms of sensitivity. This is mainly due to poor quality DNA because of degradation and hence difficulties to amplify products of the needed length. Therefore, most previous attempts to determine clonality have depended on primers binding to framework region 3 thus producing amplification products of relatively short length. In order to improve clonality analyses, we have developed a sensitive monoplex PCR-protocol using primers binding to framework region 1 with extended cycling (42 cycles) and subsequent heteroduplex analysis. For comparison, multiplex reactions with alternative primers binding to framework region 1 according to the BIOMED-2 protocol were analyzed. By the two methods combined, we were able to detect clonality of 94% (16/17) of mature small B-cell non-Hodgkin lymphomas. The results suggest that PCR with primers binding to frame work region 1 may be the method of choice when assessing clonality of mature small B-cell non-Hodgkin lymphomas on formalin-fixed tissue.

Effect of age on the repertoire of cytotoxic memory (CD8+CD45RO+) T cells in peripheral blood: the use of rearranged T cell receptor gamma genes as clonal markers

We have established a method to estimate the number of clones in peripheral blood, using rearranged T cell receptor gamma genes as clonal markers, selecting cells at random, and establishing the sizes of the clones to which they belong. Clone sizes were quantified by a clone-specific PCR test based on the VNJ junctional sequence, which typically detects 1-2 copies of its target gene. All clones chosen for study were subsequently quantified in blood, and sizes ranged from 3 x 10(-6) (1 cell in 330,000 CD8+CD45RO+ cells) to 3.5 x 10(-2) permitting numbers of clones to be estimated from the harmonic mean of clone size. Two independent estimates from a healthy young adult (20-30 years old) gave repertoires of 94,000 and 110,000 clones. Two other healthy young adults gave repertoires of 40,000 and 55,000 clones. Repertoires in four healthy active older (>75 years old) adults were more variable but generally lower, being 3600, 5500, 14,000 and 97,000 clones, despite enlarged clones making up >1% of the compartment in the last individual. Overall, young adults had smaller clones (p=0.026, non-directional Mann-Whitney U-test). If the human body contains 5 l of blood, clones have 2 x 10(3)-1.0 x 10(7) cells in blood. These results confirm a diverse repertoire of rearranged T cell receptor gamma genes. The number of clones thus defined are broadly consistent with other estimates of repertoire, despite differences in marker genes used and subsets of cells studied.

Lymphocytic infiltration and enlargement of the lacrimal glands: a new subtype of primary Sjögren's syndrome?

PURPOSE

To review the clinical, radiologic, serologic, histopathologic, immunohistochemical, and molecular genetic features of patients having Sjögren's syndrome (SS) with lacrimal gland enlargement.

DESIGN

Retrospective case series review.

PARTICIPANTS

Fourteen patients histopathologically diagnosed with SS with lacrimal enlargement. Twenty-three age- and gender-matched controls were used for comparison on radiologic analysis.

METHODS

Clinical and serologic data were determined directly or by chart review. Computed tomography images from patients were compared with those from the control group. Histopathologic sections were reviewed and graded using the Chisholm-Mason scale, and quantitative immunohistochemical analysis was applied.

MAIN OUTCOME MEASURES

Clinically, patients were assessed for age, gender, onset, symptoms and signs, systemic features, treatment, and outcome. Existing histologic specimens were reviewed according to the Chisholm-Mason scale, and then the percentages of plasma cells containing immunoglobulin (Ig) A, IgG, and IgM were determined. Imaging was assessed for lacrimal gland thickness, prolapse, density, and margin contour; extraocular muscle size; orbital tissue displacement; and proptosis.

RESULTS

Clinical and histopathological data fulfilled the revised American-European criteria for primary SS in 79% of patients. Compared with other large series of primary SS patients, similarities were found with age, xerophthalmia, parotidomegaly, and articular involvement. Differences included a lower incidence of autoantibodies, xerostomia, and extraglandular features and a higher male-to-female ratio. In almost all patients (93%), the percentage of plasma cells positive for IgA was less than 70%, consistent with SS. Compared with controls, the lacrimal glands were enlarged significantly (P<0.0001) and prolapsed (P<0.001). Involved glands had blurred margins (P<0.007), caused displacement of adjacent tissues (P = 0.03), and were associated with hyperdense fat (P = 0.007). Lymphocytic infiltration of orbital fat was present in all patients for whom fat biopsy results were available. Three patients had monoclonal infiltrates, and 1 patient experienced subsequent extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue type, 4 years after presentation.

CONCLUSIONS

The criteria used to diagnose primary SS are controversial, but both diagnostic and quantitative immunohistochemical criteria suggest that these patients, with lacrimal gland enlargement resulting from lymphocytic infiltration, represent a new subtype of primary SS. This is clinically important in view of the increased risk of lymphoma associated with SS, compared with idiopathic nonspecific lacrimal inflammation.

Characterization of peripheral T-cell lymphomas in a single North American institution by the WHO classification

BACKGROUND

All peripheral T-cell lymphomas (PTCLs) diagnosed at a single institution were evaluated to determine the unique clinical features and outcome of specific entities and test the predictive validity of the International Prognostic Index (IPI).

PATIENTS AND METHODS

Cases of PTCL seen at the British Columbia Cancer Agency between 1981 and 2000 were identified. Pathologic material was re-assessed and classified according to the WHO classification, and patients were staged and treated uniformly according to era-specific guidelines. In total, there were 199 patients with PTCL and the most common subtypes were peripheral T-cell lymphoma unspecified (PTCL-US) (59%), anaplastic large-cell lymphoma, systemic type (ALCL) (17%) and extranodal NK/T-cell lymphoma, nasal and nasal-type (NASAL) (9%). Most patients were treated with CHOP-type chemotherapy.

RESULTS

Three distinct prognostic subgroups were notable on survival analysis: favorable (cutaneous ALCL), 5-year overall survival (OS) 78%; intermediate [PTCL, ALCL and angioimmunoblastic lymphoma (AILT)], 5-year OS 35-43%; unfavorable [NASAL and enteropathy-type T-cell lymphoma (ETTL)], 5-year OS 22-24%. Furthermore, in PTCL-US and ALCL clinical separation of patients into good risk (IPI 0,1) and poor risk (IPI > or =2) subsets was demonstrated.

CONCLUSIONS

A large proportion of PTCL patients have poor risk disease and/or a histologically aggressive subtype with frequent relapse and unfavorable outcome. For these patients, treatment with CHOP chemotherapy is only minimally effective and new strategies need to be developed, an effort that will require a multi-institution international collaboration due to the rarity of most subtypes.

The role of molecular studies in lymphoma diagnosis: a review

Lymphoma classification is based on a multiparametric approach to diagnosis, in which clinical features, morphology, immunophenotype, karyotype and molecular characteristics are important to varying degrees. While in most cases, a diagnosis can be confidently established on the basis of morphology and immunophenotype alone, a small proportion of diagnostically difficult cases will rely on molecular studies to enable a definitive diagnosis. This review discusses the various molecular techniques available including Southern blotting (SB), polymerase chain reaction (PCR), fluorescence in situ hybridisation (FISH)--including multicolour-FISH/spectral karyotyping and comparative genomic hybridisation--and also gene expression profiling using cDNA microarray technology. Emphasis is given to the analysis of antigen receptor gene rearrangements and chromosomal translocations as they relate to lymphoma diagnosis and also in the setting of minimal residual disease (MRD) detection and monitoring. Laboratories performing these tests need to have expertise in these areas of testing, and there is a need for greater standardisation of molecular tests. It is important to know the sensitivity and specificity of each test as well as its limitations and the pitfalls in the interpretation of results. Above all, results of molecular testing should never be considered in isolation, and must always be interpreted in the context of clinical and other laboratory data.

Bilaterally identical monoclonality in a case of primary intraocular lymphoma

PURPOSE

To report a case of primary intraocular lymphoma possessing bilaterally identical monoclonal rearrangements of the immunoglobulin heavy chain (IgH) gene.

DESIGN

Observational case report.

METHODS

A 78-year-old woman with bilateral vitritis, subretinal infiltrates in the right eye, and no involvement of the central nervous system (CNS) was diagnosed histologically with diffuse large B-cell lymphoma by a transvitreal subretinal biopsy of the right eye. One month later, vitrectomy was performed on the left eye due to increased vitreous opacity. DNA was extracted from a vitrectomy specimen from each eye, and the third complementarity-determining region of IgH gene was analyzed by polymerase chain reaction and direct sequencing.

RESULTS

Monoclonal rearrangements of IgH gene with identical DNA sequence were detected in both eyes.

CONCLUSIONS

Bilaterally identical monoclonality was detected in a case of primary intraocular lymphoma with no CNS involvement.

Comparative analysis of NK/T-cell lymphoma and peripheral T-cell lymphoma in Korea: Clinicopathological correlations and analysis of EBV strain type and 30-bp deletion variant LMP1

Natural killer/T-cell lymphoma (NKTL) and peripheral T-cell lymphomas (PTCL) are prevalent in the Asian population and exhibit a high association with the Epstein-Barr virus (EBV). Moreover, differentiation of these two groups is often difficult and problematic. We investigated 35 cases of NKTL (22 nasal cases and 13 extranasal cases) and 30 cases of PTCL in terms of their clinical features, immunohistology, EBV positivity, EBV strain-type polymorphism and latent membrane protein 1 (LMP1) deletion variant distribution. Eighteen cases (82%) of nasal NKTL and seven (54%) of extranasal NKTL showed EBV positivity by EBV in situ hybridization. Fifteen cases (50%) of PTCL revealed EBV positivity. EBV strain type A was predominant in NKTL (18:5), and EBV strain types A and B were distributed evenly in PTCL (6:6). EBV-positive patients had significantly shorter survival than EBV-negative patients (P < 0.05), and EBV positivity correlated with advanced clinical stage (P < 0.05). Patients harboring type A EBV showed slightly poorer prognoses than those having type B, though it was not obviously statistically different (P = 0.07). The LMP1 deletion variant was prevalent in both NKTL (three wild-type LMP1, 15 deletion variants) and PTCL (three wild-type LMP1, eight deletion variants, two coexistent forms) patients, but did not have prognostic impact. Our results indicate that EBV acts as a negative prognostic factor in NKTL and PTCL, and that the intrinsic properties of a specific viral strain might influence the clinical behavior of these diseases.

Detection of mature T-cell leukemias by flow cytometry using anti-T-cell receptor V beta antibodies

A broad array of antibodies directed against the variable (V) region of the T-cell receptor (TCR) beta (V beta) chain has become available in a directly conjugated multicolor format that permits assessment of 19 of 25 V beta families, covering 70% of the normal circulating T-cell repertoire. These antibodies were used to detect expanded T-cell populations in 43 peripheral blood samples submitted for suspected T-cell malignancy. Of 43 samples, 27 were diagnosed as follows: T-cell large granular lymphocyte leukemia, 14 samples; Sézary syndrome, 4 samples; T-cell prolymphocytic leukemia, 5 samples; or T-cell non-Hodgkin lymphoma or T-cell lymphoproliferative disorder not otherwise specified, 4 samples. The remaining 16 samples were determined to be nonneoplastic. All samples were diagnosed before assessment with anti-V beta flow cytometry. By using a cutoff of 1.6 times the upper limit of normal range (ULN) to define malignant restriction of V beta use, pathologic restriction of V beta use was found directly or indirectly in all 27 samples carrying a diagnosis of malignancy and directly in 2 of 16 samples without a diagnosis of malignancy. TCR gene rearrangement studies were used to confirm V beta flow cytometry results. By using a cutoff of 1.6 times the ULN for the detection of malignancy, the antibody panel had a diagnostic sensitivity of 89% for direct detection of pathologic V beta restriction and a specificity of 88%, making it useful for rapid diagnosis of T-cell leukemia.

Non-muscle myosin heavy chain (MYH9): a new partner fused to ALK in anaplastic large cell lymphoma

In anaplastic large cell lymphoma, the ALK gene at 2p23 is known to be fused to NPM, TPM3, TPM4, TFG, ATIC, CLTC, MSN, and ALO17. All of these translocations result in the expression of chimeric ALK transcripts that are translated into fusion proteins with tyrosine kinase activity and oncogenic properties. We report a case showing a restricted cytoplasmic staining pattern of ALK and a novel chromosomal abnormality, t(2;22)(p23;q11.2), demonstrated by fluorescence in situ hybridization analysis. The result of 5' RACE analysis showed that the ALK gene was fused in-frame to a portion of the non-muscle myosin heavy chain gene, MYH9. Nucleotide sequence of the MYH9-ALK chimeric cDNA revealed that the ALK breakpoint was different from all those previously reported. It is localized in the same exonic sequence as MSN-ALK, but 6 bp downstream, resulting in an in-frame fusion of the two partner proteins. In contrast to the previously reported ALK fusion proteins, MYH9-ALK may lack a functional oligomerization domain. However, biochemical analysis showed that the new fusion protein is tyrosine phosphorylated in vivo but seems to lack tyrosine kinase activity in vitro. If further investigations confirm this latter result, the in vivo tyrosine phosphorylation of MYH9-ALK protein could involve mechanisms different from those described in the other ALK hybrid proteins.

Comparative evaluation of PCR-based methods for the assessment of T cell clonality in the diagnosis of T cell lymphoma

AIMS

The accurate diagnosis of T cell lymphoma often depends on the demonstration of a monoclonal T cell population in a lymphoproliferative disorder (LPD). The aim of this study was to evaluate four polymerase chain reaction (PCR)-based methods used to analyse T cell receptor (TCR) gene rearrangements in the assessment of T cell clonality.

METHODS

DNA was tested from 23 T cell neoplasms, seven B cell non-Hodgkin's lymphomas (B-NHL), three Hodgkin's lymphomas (HL), 14 benign LPD and peripheral blood from a healthy donor. TCRgamma rearrangements were assessed by McCarthy's et al. two primer set method, Benhattar's et al. linear pre-amplification method, and Chhanabhai's et aL heteroduplex method. TCRbeta D-J rearrangements were analysed by Slack's et al. method.

RESULTS

Monoclonal TCRgamma rearrangements were found in 91% (21 of 23) of T cell neoplasms using McCarthy's et al. method; in 83% (19 of 23) using Benhattar's et al. or Chhanabhai's et al. methods and monoclonal TCRbeta rearrangements were found in 43% (10 of 23) using Slack's et al. method. Monoclonality was established in all T cell neoplasms using one or more PCR methods. One follicular B-NHL had inappropriate monoclonal TCRbeta rearrangement, while the remaining B-NHL and all HL samples had no monoclonal TCRgamma or TCRbeta rearrangements. In addition to polyclonal products, one reactive lymph node had oligoclonal TCRgamma rearrangements and two others generated monoclonal products of uncertain significance. McCarthy's et al. TCRgamma method was the most sensitive in establishing T cell monoclonality, and in combination with Slack's et al. TCRbeta method, monoclonality was demonstrated in 100% of T cell neoplasms (23 of 23).

CONCLUSIONS

These data indicate that multiple primer set PCR methods should obviate a need for the more expensive and time-consuming Southern blot (SB) technique and are the preferred diagnostic molecular test for assessing T cell clonality.

Effectiveness of capillary electrophoresis using fluorescent-labeled primers in detecting T-cell receptor gamma gene rearrangements

We describe the use of fluorescent-labeled primers to analyze T-cell receptor gamma gene rearrangements (TCR gamma GR) using capillary electrophoresis in the ABI Prism 310 Genetic Analyzer. We also compare the performance with denaturing gradient gel electrophoresis (DGGE). In a single multiplex polymerase chain reaction (PCR) we amplified TCR gamma GR with primers for all known groups of variable region genes, and joining region genes described in lymphoid neoplasms. Ten reactive samples, followed by five cell lines and 25 tumor samples with 41 individual TCR gamma GR (due to many biallelic rearrangements) previously identified by DGGE, were analyzed to validate the technique. The capillary electrophoresis protocol has 92% concordance for both TCR clonal status (23 of 25) and 95% concordance in the number of individual TCR gamma GR (38 of 41) identified by DGGE. The reproducible sensitivity for detecting TCR gamma GR diluted in reactive lymphoid DNA is 2% in clinical applications. Discrimination of predominant rearrangements requires a minimum ratio of two times the height of the normal distribution of polyclonal peaks. Capillary electrophoresis can provide results within 60 minutes for each specimen after PCR is complete. Capillary electrophoresis provides a faster result than sequence-based separation methods and gives an archival electronic record. Fluorescent labeling allows the identification of both the variable and joining gene segments used in a TCR gamma GR. The effectiveness of capillary electrophoresis is similar to DGGE.

Heavy multinodular cutaneous lymphoid infiltrates: clinicopathologic features and B-cell clonality

BACKGROUND

Criteria for distinguishing between cutaneous lymphoid hyperplasia (CLH) and low-grade B-cell lymphoma are not well defined. We examined the hypothesis that the presence of a clonal B-cell population in heavy multinodular lymphoid infiltrates correlates with clinical presentation and outcome.

METHODS

We identified 29 patients with skin lesions characterized histologically by a heavy dermal lymphocytic infiltrate with a multinodular architecture and extension into deep dermis and subcutaneous fat. Clonality was assessed immunophenotypically by light-chain restriction and also by analysis for IgH-gene rearrangement using PCR on DNA extracted from paraffin blocks.

RESULTS

Follow-up (mean 80 months; median 45 months) was obtained in all patients. Twenty-four patients (83%) presented with a solitary lesion: only four had solitary recurrences, and none developed multiple synchronous lesions or systemic B-cell lymphoma. However, 9/24 of these solitary lesions (38%) were clonal by light-chain restriction or IgH PCR; 5/29 patients (17%) presented with multiple recurrent lesions and continued to develop lesions during the period of follow-up; 3/5 patients (60%) with multiple lesions demonstrated a B-cell clone. No patient developed systemic B-cell lymphoma.

CONCLUSIONS

Heavy, multinodular cutaneous lymphoid infiltrates have an excellent prognosis. Multiple lesions at presentation are the best predictor of recurrent multiple lesions confined to the skin. The presence of a clonal B-cell population does not correlate with clinical presentation or histology, nor does it predict development of further lesions or systemic lymphoma.

Heteroduplex analysis of T-cell receptor gamma gene rearrangement as an adjuvant diagnostic tool in skin biopsies for erythroderma

BACKGROUND

Erythroderma, defined as red skin covering most of the body surface often accompanied or followed by exfoliation, is the clinical manifestation of at least six different underlying etiologies with allergic or irritant contact dermatitis, atopic/asteotic dermatitis, pityriasis rubra pilaris (PRP), psoriasis, and seborrheic dermatitis accounting for the majority of cases. Approximately 10% of cases are due to adverse drug reactions with roughly another 10% due to cutaneous T-cell lymphoma (CTCL), predominantly mycosis fungoides, or leukemia. It is clear from multiple studies that the clinical diagnosis of the underlying entity is often difficult, as these diseases can present in a very similar fashion. A skin biopsy is usually employed in this setting as a diagnostic tool. However, the histopathologic diagnosis of the underlying cause is complicated by the subtlety of the distinguishing histologic features. In this situation, an ancillary technique demonstrating the presence of a monoclonal T-cell proliferation could help to rule in or out CTCL in cases that clinically and histopathologically do not allow a definitive diagnosis.

METHODS

We retrospectively studied 25 biopsies from sixteen patients who presented to the Stanford Dermatology Clinic with erythroderma. We examined the specimens morphologically and analyzed the gamma chain of the T-cell receptor (TCR- gamma) by polymerase chain reaction (PCR) followed by heteroduplex analysis for clonality. We then correlated the results of our PCR and heteroduplex analyses with the patients' clinical outcomes.

RESULTS

Four biopsies, from three patients, contained clonal TCR-gamma rearrangements; the four biopsies, all of which were equivocal histologically, correlated to diagnoses of mycosis fungoides (MF) or Sézary syndrome (SS). Twenty-one biopsies contained polyclonal T-cell populations. Eighteen of these biopsies represent patients with inflammatory dermatoses. Three of these biopsies, all of which were taken from a single patient, correlate to a diagnosis of MF.

CONCLUSION

TCR-gamma PCR heteroduplex analysis seems to represent an important adjuvant diagnostic tool that, used in conjunction with histopathology and clinical history, could help to clarify the underlying etiology of erythroderma.

Comparative genomic hybridization study of nasal-type NK/T-cell lymphoma

BACKGROUND

Nasal-type NK/T-cell lymphoma is a rare type of non-Hodgkin's lymphoma. The genetic changes associated with pathogenesis have not been well defined. This study investigates the nonrandom genetic alteration of nasal-type NK/T-cell lymphoma.

METHODS

Nine cases were studied. Comparative genomic hybridization (CGH) was carried out using fresh tumor tissues of seven nasal-type NK/T-cell lymphomas. To complement the data by CGH, loss of heterozygosity (LOH) of chromosomes 6q, 1p, and 17p using polymorphic markers and p53 gene mutation by polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) were analyzed.

RESULTS

The DNA copy number changes of seven nasal-type NK/T-cell lymphomas were gains on chromosomes 2q(5), 13q(4), 10q(3), 21q(2), 3q(2), 5q(2), and 17q(2), and losses involving chromosomes 1p(4), 17p(4), 12q(3), 13q(2), and 6q(1). One of six cases informative for at least two markers for chromosome 6q showed LOH at D6S300, D6S1639, D6S261, D6S407, and D6S292. Two cases showing loss of 1p and 17q by CGH revealed LOH at D1S214, D1S503, and D17S559. P53 mutation was detected in exon 8 in one of nine cases.

CONCLUSIONS

Frequent DNA losses at 1p, 17p, and 12q and gains at 2q, 13q, and 10q suggested that these regions could be targets for further molecular genetic analysis to investigate tumor suppressor genes or oncogenes associated with tumorigenesis of NK/T-cell lymphoma. Infrequent alteration of 6q contrary to previous studies raises doubt about an implication of 6q loss in the pathogenesis of early-stage NK/T-cell lymphoma. Further studies on more defined cases are required to verify their association.

Detection of T-cell receptor-gamma gene rearrangement in lymphoproliferative disorders by temperature gradient gel electrophoresis

OBJECTIVE

Polymerase chain reaction amplification of DNA for T-cell receptor (TCR) gene rearrangement analysis is helpful in the evaluation of T-cell lymphoproliferative disorders. Detection of polymerase chain reaction products is limited by the poor resolution of bands analyzed by agarose or polyacrylamide gel electrophoresis. To improve the detection of a clonal T-cell population, we used temperature gradient gel electrophoresis (TGGE) as an alternative method for analysis of TCR gene rearrangement.

DESIGN

One hundred eighteen archival DNA samples were randomly selected based on previous Southern blot analysis results. Samples included 58 T-cell neoplasms with positivity for TCR beta gene rearrangement, 22 cases of reactive hyperplasia with germline pattern for both TCR beta and J(H), and 38 patients with B-cell lymphoma. MOLT-16, a T-cell lymphoblastic cell line, was used for the sensitivity assay. Polymerase chain reaction was performed using GC-clamped multiplex primers to amplify the TCR gamma locus and was analyzed by TGGE. The range of temperature gradients was empirically determined for optimal resolution of bands.

RESULTS

The sensitivity of TGGE was 0.1% when DNA from the MOLT-16 cell line was serially diluted with DNA from reactive lymphoid tissue. Fifty-four (93%) of 58 T-cell neoplasms with TCR beta gene rearrangements showed rearrangement patterns by TCR gamma TGGE, and only 1 of 60 samples (reactive or B-cell lymphomas) showed evidence of gene rearrangement by TGGE. Patients with T-cell neoplasm and involvement of multiple sites showed an identical migration pattern by TGGE analysis.

CONCLUSION

We demonstrate that TGGE is an effective method for analysis of TCR gene rearrangement in the evaluation of nodal and extranodal lymphoid lesions.

Polymerase chain reaction in the diagnosis of T-cell lymphoma in paraffin-embedded bone marrow biopsies: a comparative study

AIMS

In routine histological analysis of bone marrow biopsies, the distinction between reactive T-cell infiltrates and T-cell lymphoma can be difficult, even with the use of extensive immunohistochemistry. The aim of this study was to evaluate the diagnostic contribution of TCR-gamma gene rearrangement analysed by PCR.

METHODS AND RESULTS

The samples studied consisted of 46 paraffin-embedded bone marrow biopsies (diagnosis, staging and follow-up) from 26 patients with T-cell lymphoma. The bone marrow biopsies were categorized into three groups according to the morphological and immunohistochemical results. Group 1, positive for T-cell lymphoma (24 bone marrow biopsies), group 2, suspicion of T-cell lymphoma (15 bone marrow biopsies) and group 3, negative for T-cell lymphoma (seven bone marrow biopsies). DNA could be amplified in 45/46 bone marrow biopsies (98%). Clonal rearrangement was detected in 30/45 bone marrow biopsies tested (67%) including 15/24 bone marrow biopsies (62.5%) of group 1, 11/14 (78.5%) of group 2 and 4/7 (57%) of group 3. In total, PCR analysis supported a diagnosis of T-cell lymphoma in 15/45 bone marrow biopsies (33%), in which histological and/or immunohistochemical examination provided inconclusive evidence of malignancy.

CONCLUSIONS

TCR-gamma PCR is a complementary tool for the assessment of T-cell lymphoma in bone marrow biopsies. Optimal evaluation of bone marrow biopsies requires an integrative approach of all available results from morphology, immunohistochemistry, molecular biology and clinical data.

Sensitive detection of clonal immunoglobulin rearrangements in frozen and paraffin embedded tissues by polymerase chain reaction heteroduplex analysis

Molecular detection of a clonal population of B or T cells through analysis of rearranged antigen receptor genes is an essential adjunct to the morphologic, flow cytometric, and immunohistochemical evaluation of tissue specimens for the presence of leukemia or lymphoma. Combining polymerase chain reaction (PCR) with heteroduplex annealing and polyacrylamide gel electrophoresis (PAGE) has been used to detect clonal T-cell receptor rearrangements, particularly in skin biopsy specimens. The authors have developed a similar PCR heteroduplex assay for detection of clonal VDJ immunoglobulin gene rearrangements using two sets of primers based on relatively conserved consensus regions in the J(H) and framework I and 2 regions of the immunoglobulin heavy chain V region gene. This method is able to detect a clonal rearrangement when the clone comprises as little as 1% of the population in a polyclonal B-cell background. It may be used on fresh, frozen, or paraffin-embedded tissue and detects a clonal population in a majority of lymphoma subtypes. Compared with conventional PCR analysis, this method requires only a short additional cycle of denaturation and slow renaturation before PAGE. Interpretation is simplified as the clonal PCR product migrates away from the polyclonal background products.

Clinicopathologic and genotypic study of extranodal nasal-type natural killer/T-cell lymphoma and natural killer precursor lymphoma among Koreans

BACKGROUND

This study aimed to define genotypic profile and to describe the clinicopathologic features of nasal-type natural killer (NK)/T-cell lymphoma of nasal and extranasal origin and NK precursor lymphoma.

METHODS

NK/T-cell lymphomas from the upper aerodigestive tract (n = 45), skin (n = 2), gastrointestinal tract (n = 3), and soft tissue (n = 2) and NK precursor neoplasms (n = 3) were studied. Immunophenotype was analyzed by immunohistochemistry and flow cytometry. In situ hybridization with EBER 1/2 RNA probes was performed. T-Cell Receptor (TCR)-gamma gene rearrangement was analyzed by seminested polymerase chain reaction with heteroduplex analysis. Overall survival rate was correlated with clinicopathologic parameters and compared by Wilcoxon test.

RESULTS

Clonal TCR-gamma gene rearrangement was detected in 3 of 31 upper aerodigestive and 1 of 2 skin tumors. When immunostained using paraffin embedded tissue, 6 upper aerodigestive lymphomas were negative for CD56 in which 4 cases lacked clonal TCR gene rearrangement. Epstein-Barr virus (EBV) mRNA was detected in 33 upper aerodigestive tumors including 26 of 29 nasal tumors (90%), and 7 of 10 extranasal tumors (70%). There was no histologic, immunophenotypic, or genotypic differences according to the lineage and EBV association in upper aerodigestive lymphomas. Among the patients with upper aerodigestive tumors, overall 1-year survival rate was 41%, and correlated well with the stage (P < 0.05) but not with the size of tumor cells, EBV status, and lineage (P > 0.05). Median survival rate of lymphomas from other sites excluding upper aerodigestive tract was not significantly different from that of upper aerodigestive lymphomas with same stage (P > 0.05). Unlike nasal-type NK/T-cell lymphomas, NK precursor lymphoma involved the bone marrow and lymph nodes at initial presentation or in the course of disease. Tumor cells were positive for TdT in all and myeloid markers in two. TCR gene rearrangement was germ line.

CONCLUSIONS

Most upper aerodigestive nasal-type NK/T-cell lymphomas among Koreans are genotypically of NK derivation and few belong to T lineage. Presence or absence of EBV has no significant correlation with the histologic changes and the lineage of these lymphomas.

Development of a biologically distinct EBV-related lymphoproliferative disorder following autologous bone marrow transplantation for an EBV-negative post-renal allograft Burkitt's lymphoma

Post-transplant lymphoproliferative disorder (PTLD) is a known complication of both solid organ transplantation and allogeneic bone marrow transplantation (BMT) but is rarely seen following autologous BMT. We report the case of a 45 year-old female who developed Burkitt's lymphoma eight years after a renal allograft. This PTLD was found to have lambda light chain restriction, contained del(8)(q24) and add(14)(q32), and was negative for EBV on immunohistochemical and DNA-based PCR analyses. Immunoglobulin heavy chain (IgH) PCR studies revealed a prominent clonal rearrangement. She responded to intravenous cyclophosphamide and proceeded to high-dose chemoradiotherapy and mafosfamide-purged autologous BMT. Thirty-nine days post-BMT she presented with cough and fever and developed hepatic dysfunction; abnormal lymphoplasmacytoid cells were noted in the peripheral blood. Investigations revealed kappa light chain restriction, an oligoclonal IgH rearrangement, a normal karyotype and PCR studies for EBV were positive, consistent with a clinically and biologically distinct PTLD. She initially improved following discontinuation of immunosuppression, but then deteriorated abruptly and died 58 days post-BMT. It is likely that the two separate episodes of PTLD in this patient, one of which was atypical, arose as a result of both the chronic use of cyclosporine and the impairment of cell-mediated immunity associated with autologous BMT. The sequence of events in this patient should contribute to a better understanding of late-onset, EBV-negative PTLD.

Comparison of capillary electrophoresis and polyacrylamide gel electrophoresis for the evaluation of T and B cell clonality by polymerase chain reaction

Polymerase chain reaction (PCR) technique is widely used in the diagnosis of lymphoma, and PCR amplification products are typically detected by polyacrylamide gel electrophoresis (PAGE). However, the identification of small clonal populations, or the distinction of clonal PCR products in a polyclonal milieu remains difficult, requiring technically demanding alterations to gel analysis. This study describes an alternative approach using a capillary electrophoresis (CE) system to produce an accurately sized electropherogram. A variety of patient samples were examined, including solid tissue, peripheral blood, bone marrow aspirates, and paraffin-embedded tissue. A total of 28 samples were evaluated by PCR for B-cell clonality by detection of immunoglobulin heavy chain gene rearrangement and 29 samples for T-cell clonality by detection of T-cell gamma locus gene rearrangement. Standard 10% PAGE analysis of PCR products was compared with CE. There was a 100% concordance in the assessment of both B-cell and T-cell clonality. Dilution studies with the SUP-B15 cell line showed a detection limit of 0.03% for B-cell clonality and 0.05% for T-cell clonality using CE, versus 0.2% to 1%, respectively for PAGE. Automated, fluorescent analysis of PCR products by CE seems to be at least equally as effective as gel-based analysis for the detection of clonal B-cell and T-cell populations. Moreover. CE offers superior resolution and improved sensitivity, thus representing a significant improvement over traditional gel electrophoretic techniques in these regards.

PCR-heteroduplex analysis of T-cell receptor gamma gene rearrangement in paraffin-embedded skin biopsies

We developed a rapid, simple, and sensitive method for the detection of T-cell receptor-gamma (TCRgamma) gene rearrangements in paraffin-embedded skin biopsies. Available techniques often require either fresh tissue, several primer pairs, nested amplifications, or specialized electrophoresis steps such as denaturing gradient gel electrophoresis. Our method is based on heteroduplex analysis of polymerase chain reaction (PCR) products of the TCRgamma in a nondenaturing modified polyacrylamide gel using a single pair of primers and is adapted for paraffin-embedded tissue. When tested against Southern blot analysis, the PCR results correlated in 8 of 9 cases. Six mature cutaneous B-cell lymphomas and 29 inflammatory skin disorders all resulted in a polyclonal amplification pattern. When analyzing 3-mm or 4-mm punch biopsies of 51 cases of cutaneous T-cell lymphoma, 37 (72.5%) showed a clonal rearrangement with this technique. For 7 cases of patch stage mycosis fungoides, frozen tissue and formalin-fixed and paraffin-embedded tissue was available, and in 5 of 7 cases (71%), the results in frozen and paraffin-embedded tissue were concordant. One case showed a clonal pattern in frozen tissue but not in paraffin-embedded tissue, and one case was polyclonal in frozen tissue but monoclonal in paraffin-embedded tissue. Using serial dilutions of DNA from a T-cell ALL in a polyclonal background (tonsil), we established a sensitivity of 0.5%. Heteroduplex PCR of the TCRgamma is a rapid, sensitive, and inexpensive screening procedure as well as a useful adjunct to histologic analysis and immunophenotyping of cutaneous T-cell proliferations.

Peripheral T-cell lymphoma complicated by a proliferation of large B cells

We studied 14 cases that showed a morphologic appearance of peripheral T-cell lymphoma and contained substantial numbers of CD20+ large B cells. In all but 2 cases, the CD20+ large cells showed a mix of kappa and lambda light chain expression. Two cases showed a focal predominance of kappa expression. In situ hybridization using the EBER1 probe for detection of Epstein-Barr virus (EBV) RNA was performed on every case. EBV RNA was present in 10 cases. Of 8 cases with EBV RNA stained by immunohistochemistry for the latent membrane protein of EBV, 6 were positive. Double-labeling immunohistochemistry and in situ hybridization confirmed that EBV was present in the large B cells. Polymerase chain reaction (PCR) analysis showed a clonal rearrangement of the T-cell receptor (TCR)-gamma chain gene in 12 of 13 cases tested. One additional case showed a clonal rearrangement of the TCR-beta chain gene by Southern blot hybridization. PCR analysis showed a clonal immunoglobulin gene rearrangement in 5 cases, a suggestion of a clonal rearrangement in 1, an oligoclonal pattern in 4, and a polyclonal pattern in 4. The finding of large B and T cells may result in a misdiagnosis of a reactive process or of T-cell-rich B-cell lymphoma. The presence of EBV in some cases could cause further confusion with the reactive T- and B-immunoblastic proliferation of infectious mononucleosis.

T-cell clonality determination using polymerase chain reaction (PCR) amplification of the T-cell receptor gamma-chain gene and capillary electrophoresis of fluorescently labeled PCR products

We compared the effectiveness of polymerase chain reaction (PCR) and DNA blot analysis (DBA) for detecting clonal T-cell populations and investigated whether a nonradioactive PCR method could be used in routine clinical diagnosis. We analyzed DNA from 117 cases for T-cell clonality by PCR amplification. DBA was performed on 77 of these cases. Denaturing polyacrylamide gel electrophoresis (PCR-PAGE) of radiolabeled PCR products and capillary electrophoresis (PCR-CE) of fluorescently labeled PCR products were used for PCR product separation and quantitation. Complete agreement was obtained between PCR-PAGE and DBA in 67 of 77 cases. One case was positive by DBA and negative by PCR-PAGE, and 3 cases were positive by PAGE and negative by DBA. Five cases indeterminate by DBA were positive by PCR-PAGE, and 1 indeterminate case was negative by PCR-PAGE. In the comparison of PCR-PAGE and PCR-CE, of 63 cases with height ratios less than 2.0, all were negative by PCR-PAGE. Of 52 cases with height ratios of 2.0 or more, 50 were positive by PCR-PAGE. We conclude that PCR-CE is analytically equivalent to DBA and PCR-PAGE for detecting clonal T-cell populations. The PCR-CE method is semiquantitative and, therefore, may be more objective than gel-based methods.

Spontaneously relapsing clonal, mucosal cytotoxic T-cell lymphoproliferative disorder: case report and review of the literature

Primary T-cell lymphoma of the gastrointestinal tract is a rare and usually aggressive disorder that may be associated with celiac disease. The authors describe a unique case of a clonal proliferation of CD8+ T cells involving the oral mucosa, ileum, and colon of a 35-year-old man that has regressed spontaneously and recurred numerous times over a 9-year period without treatment. The patient's symptoms were limited to occasional rectal bleeding and recurring painful oral ulcers. Within the intestine, these collections of small T cells induced minimal architectural distortions and did not show extensive epitheliotrophism. Polymerase chain reaction and sequencing analyses revealed that the identical T-cell clone has been present for more than 9 years and in different mucosal locations in this patient. This may represent a unique T-cell lymphoproliferative process akin to a mucosal counterpart of lymphomatoid papulosis of the skin.

Detection of immunoglobulin kappa light chain rearrangements by polymerase chain reaction. An improved method for detecting clonal B-cell lymphoproliferative disorders

The clonal determination of B-cell lymphoproliferative disorders by immunoglobulin heavy chain (IgH) rearrangement by polymerase chain reaction (PCR) is widely used. However, few attempts have been made to detect immunoglobulin kappa light chain (Igkappa) gene rearrangement using PCR. We studied 145 cases of B-cell neoplasms, along with 58 atypical and 18 reactive lymphoproliferative disorders, using newly designed degenerate oligoprimers recognizing the framework 3 (FR3kappa) and the joint (Jkappa) regions of the Igkappa gene. PCR products were analyzed on nondenaturing polyacrylamide gel (ndPAGE). Clonal B-cell determination was further investigated using IgH rearrangement and t(11:14) or t(14:18). By combining these methods, we detected either clonality or translocation in 117 of 137 cases (85%) in mature B-cell neoplasms. The additional analysis of Igkappa rearrangement improved sensitivity from 66% to 85%. To investigate whether the Ig gene configuration could be characterized using Igkappa PCR in B-cell neoplasms showing severe breakdown of genomic DNA, 18 selected cases were analyzed. Successful amplification was detected in 72% of the cases using either FR3/2-JH and/or FR3Jkappa oligoprimers. Finally, clonality was detected in 21 of 58 atypical B-cell proliferations, and among them, the atypical marginal cell (54%) and atypical large cell (50%) proliferations showed the highest frequency of clonal immunoglobulin gene products. We concluded that PCR/ndPAGE analysis of Igkappa is a sensitive, rapid, and efficient method for assessing clonality in conjunction with IgH and specific translocation analysis. This approach is particularly useful in the characterization of B-cell lymphoproliferative disorders in archival material with poor preservation of the genomic DNA.

A rapid restriction fragment length polymorphism polymerase chain reaction-based diagnostic method for identification of T-cell lymphoproliferative disorders

BACKGROUND

Identification of a clonal proliferation of lymphocytes is central to the diagnosis of lymphoma compared with a reactive lymphoproliferation. We propose a novel diagnostic technique based on restriction fragment length polymorphism (RFLP) of amplified polymerase chain reaction (PCR) products of the T-cell receptor -gamma (TCR-gamma) gene rearrangement to rapidly identify monoclonality in T-cell lymphomas and improve diagnosis of malignancy.

MATERIALS AND METHODS

DNA from peripheral blood mononuclear cells (PBMCs) of 10 healthy volunteers and 7 T-cell lymphoma patients were isolated and the TCR-gamma was amplified with consensus primers for the different variable (V) and joining (J) segments. Restriction digests were done using BstN1 and the fragments separated via gel electrophoresis. Verification was by Southern analysis.

RESULTS

Restriction digests of the 10 healthy controls show a characteristic nine-band digest pattern whereas the restriction digests of the 7 T-cell lymphomas each show altered banding patterns completely distinct from the normal nine-band pattern (Fisher exact test = 0.00005). Sensitivity assays demonstrate the test can detect clonal populations representing 2% of total. This method also enables identification of particular clonal populations. The entire procedure can be performed in one day, does not require radioactivity, and requires only small quantities of specimens.

CONCLUSIONS

This RFLP-PCR-based diagnostic method for T-cell lymphomas is specific, sensitive, efficient, and reproducible, and enables the identification of clonally expanded populations of T lymphocytes. It offers the ability to identify particular clonal populations, as with Southern analysis, combined with the benefits of a PCR method.

Use of the polymerase chain reaction in the evaluation of cutaneous T-cell infiltrates

Histologic evaluation of suspected cutaneous T-cell neoplasia is challenging. There is significant overlap with features of benign condition, and neoplastic cells often occur in a reactive background. Recently, molecular techniques using paraffin-embedded tissue have been applied to the diagnosis of cutaneous T-cell infiltrates. These methods are useful for determining whether a clonal population of T-cells is present. The advantages and limitation of molecular diagnostic methods in the diagnosis of cutaneous T-cell infiltrates are discussed.

Primary non-Hodgkin's lymphoma and malakoplakia of the vagina: a case report

The vagina is a rare site for both primary non-Hodgkin's lymphoma and malakoplakia. We report a case of concurrent diffuse large B-cell lymphoma and malakoplakia of the vagina in a 67-year-old woman presenting with a vaginal discharge and a vaginal mass. The patient had two biopsy specimens reported as showing malakoplakia only, followed by a third biopsy specimen 10 months later which was diagnosed as diffuse large B-cell lymphoma. Review of the first two biopsy specimens showed areas of histiocytes with Michaelis-Gutman bodies merging with areas of cells with slightly larger nuclei and more amphophilic cytoplasm. Immunohistochemistry for the B-cell marker L-26 (CD20) and polymerase chain reaction analysis of the immunoglobulin heavy chain gene were helpful in retrospectively distinguishing the population of diffuse large B-cell lymphoma from the areas of malakoplakia. The third biopsy specimen showed sheets of large atypical lymphoid cells characteristic of a large cell lymphoma. Malakoplakia has been described in association with a variety of cancers, and this is only the second report of malakoplakia associated with non-Hodgkin's lymphoma. Considering the rarity of these two entities in the vagina, it is unlikely that the association in this case is coincidental, raising the possibilities of an unusual reaction to the presence of lymphoma or a common pathogenesis such as underlying chronic inflammation. Epstein-Barr virus DNA was detected in the second biopsy specimen, suggesting a possible role in the pathogenesis of this lymphoma.

Prognostic Significance of Anaplastic Lymphoma Kinase (ALK) Protein Expression in Adults With Anaplastic Large Cell Lymphoma

Anaplastic large cell lymphoma (ALCL) is an aggressive lymphoma that is frequently associated with the t(2;5)(p23;q35), resulting in expression of a fusion protein, nucleophosmin-anaplastic lymphoma kinase (NPM-ALK), which can be detected by either monoclonal or polyclonal antibodies to the ALK protein. The clinical features of adults with ALCL are incompletely described, and the prognostic factors that are useful for predicting survival remain unclear. This report describes the clinical and laboratory findings in 70 adults with systemic ALCL who were treated with curative intent. We attempted to identify the clinical and pathological factors of prognostic importance, including the International Prognostic Index (IPI), immunophenotype, and expression of the ALK protein. The median age of the patients was 49 years (range, 15 to 75). There were 26 women and 44 men with a median follow-up of 50 months for living patients. Advanced stage was present in 56% and B symptoms were noted in 70% of the patients. Immunostains showed that 46% of the cases had a T-cell phenotype, 36% a null phenotype, and 18% a B-cell phenotype. The expression of ALK protein was found in 51% of the cases. The IPI factors were evenly distributed between the ALK+ and ALK− groups, except that the ALK+ patients were younger (median age, 30 v 61 years; P &lt; .002). The ALK+ cohort included cases with null (44%), T-cell (42%), and B-cell (14%) phenotypes. All 10 cases with cytogenetic or molecular evidence of a t(2;5) were ALK+. The 5-year overall survival (OS) of the entire cohort was 65%. The 5-year OS of the ALK+ and ALK− cases was 79% and 46%, respectively (P &lt; .0003). Analysis of only the T-cell/null cases (n = 57) showed a 5-year OS of 93% for the ALK+ cases and only 37% for the ALK− cases (P &lt; .00001). Univariate analysis of the clinical features showed that age ≤60 years (P &lt; .007), a normal serum lactate dehydrogenase (LDH) (P &lt; .00001), a good performance status (Eastern Cooperative Oncology Group [ECOG] &lt;2) (P&lt; .03), ≤1 extranodal site of disease (P &lt; .012), and an IPI score ≤3 (P &lt; .00001) were associated with improved OS. Although a younger age correlated with ALK positivity, multivariate analysis showed that only a normal serum LDH (P &lt; .00001), an IPI score of ≤3 (P &lt; .0005), and ALK protein expression (P &lt; .005) predicted independently for an improved OS. We conclude that ALCL is a heterogeneous disorder. However, ALK protein expression is an independent predictor of survival and serves as a useful biologic marker of a specific disease entity within the spectrum of ALCL.

Prognostic Significance of Anaplastic Lymphoma Kinase (ALK) Protein Expression in Adults With Anaplastic Large Cell Lymphoma

Anaplastic large cell lymphoma (ALCL) is an aggressive lymphoma that is frequently associated with the t(2;5)(p23;q35), resulting in expression of a fusion protein, nucleophosmin-anaplastic lymphoma kinase (NPM-ALK), which can be detected by either monoclonal or polyclonal antibodies to the ALK protein. The clinical features of adults with ALCL are incompletely described, and the prognostic factors that are useful for predicting survival remain unclear. This report describes the clinical and laboratory findings in 70 adults with systemic ALCL who were treated with curative intent. We attempted to identify the clinical and pathological factors of prognostic importance, including the International Prognostic Index (IPI), immunophenotype, and expression of the ALK protein. The median age of the patients was 49 years (range, 15 to 75). There were 26 women and 44 men with a median follow-up of 50 months for living patients. Advanced stage was present in 56% and B symptoms were noted in 70% of the patients. Immunostains showed that 46% of the cases had a T-cell phenotype, 36% a null phenotype, and 18% a B-cell phenotype. The expression of ALK protein was found in 51% of the cases. The IPI factors were evenly distributed between the ALK+ and ALK− groups, except that the ALK+ patients were younger (median age, 30 v 61 years; P < .002). The ALK+ cohort included cases with null (44%), T-cell (42%), and B-cell (14%) phenotypes. All 10 cases with cytogenetic or molecular evidence of a t(2;5) were ALK+. The 5-year overall survival (OS) of the entire cohort was 65%. The 5-year OS of the ALK+ and ALK− cases was 79% and 46%, respectively (P < .0003). Analysis of only the T-cell/null cases (n = 57) showed a 5-year OS of 93% for the ALK+ cases and only 37% for the ALK− cases (P < .00001). Univariate analysis of the clinical features showed that age ≤60 years (P < .007), a normal serum lactate dehydrogenase (LDH) (P < .00001), a good performance status (Eastern Cooperative Oncology Group [ECOG] <2) (P< .03), ≤1 extranodal site of disease (P < .012), and an IPI score ≤3 (P < .00001) were associated with improved OS. Although a younger age correlated with ALK positivity, multivariate analysis showed that only a normal serum LDH (P < .00001), an IPI score of ≤3 (P < .0005), and ALK protein expression (P < .005) predicted independently for an improved OS. We conclude that ALCL is a heterogeneous disorder. However, ALK protein expression is an independent predictor of survival and serves as a useful biologic marker of a specific disease entity within the spectrum of ALCL.

Primary follicular lymphoma of the testis in childhood

BACKGROUND

Follicular lymphoma in childhood is rare. The authors present four unusual primary follicular lymphomas of the testis in children.

METHODS

Tumor tissue was evaluated using light microscopy, immunohistochemistry, flow cytometry, and polymerase chain reaction (PCR) for immunoglobulin heavy chain (IgH) and bcl-2 gene rearrangements. Southern blot and immunohistochemical analyses were used to detect bcl-6 gene rearrangements and protein expression, respectively.

RESULTS

Four young boys ranging in age from 3 to 10 years were diagnosed with Stage IE follicular large cell lymphoma (Grade 3). A B-cell phenotype was documented in all four cases; monoclonality was confirmed in three cases by demonstration of light chain restriction or clonal IgH gene rearrangement. None of the lymphomas expressed Bcl-2 or p53 protein, and bcl-2 gene rearrangements were not found in the three lymphomas studied. In contrast, Bcl-6 protein was expressed by all three lymphomas studied, and a bcl-6 gene rearrangement was detected in the one case analyzed by Southern blot. All four boys were treated by orchiectomy and combination chemotherapy and are alive with no evidence of disease 18-44 months following their initial diagnoses.

CONCLUSIONS

Follicular lymphomas may rarely occur as primary testicular tumors in prepubertal boys and, when localized, appear to be associated with a favorable prognosis. In contrast to follicular lymphoma in adults, pediatric follicular lymphomas of the testis are usually of large cell type (Grade 3) and lack bcl-2 or p53 abnormalities. The identification, in one case, of a bcl-6 gene rearrangement suggests an alternate molecular pathogenesis for pediatric follicular lymphoma.

Molecular methods for detecting t(11;14) translocations in mantle-cell lymphomas

The t(11;14)(q13;q32) and its molecular counterpart, bcl1/JH, are characteristic of mantle-cell lymphomas (MCL). Molecular detection of the translocation is useful in diagnosis and classification, and also shows promise in detecting minimal residual disease. The purpose of this study was to determine the frequency of detecting bcl1/JH by polymerase chain reaction (PCR) compared with Southern blot analysis in cases proven by cytogenetic analysis to harbor t(11;14). Southern blot analysis using two probes targeting the major translocation cluster (MTC) and a third probe targeting the p94 region was performed, along with PCR using two different bcl1 MTC primers, on 18 cases of MCL known to have t(11;14). Southern blot analysis revealed bcl1 rearrangement in 13 of 18 cases (72%), 12 with MTC breakpoints and 1 with a p94 breakpoint. The 2.1-kb MTC probe "b" was superior to the smaller 700-bp probe "a" in detecting these rearrangements. The MTC translocation was identified by PCR in 10 of 12 cases, and both primer sets that were tested performed equally well. This study illustrates the frequency with which molecular methods detect known t(11;14) translocations in MCLs. These results may help clinical laboratory scientists optimize their procedure for detecting bcl1 translocations by molecular methods at initial diagnosis and for purposes of detecting minimal residual disease.