RESUMO
Links between premorbid physical activity (PA) and disease onset/course in patients with anorexia nervosa (AN) remain unclear. The aim was to assess self-reported PA as a predictor of change in percent median BMI (%mBMI) and length of hospital stay (LOS). Five PA domains were assessed via semi-structured interview in adolescents with AN at hospitalization: premorbid PA in school grades 1-6 (PA1-6); PA before AN onset (PA-pre) and after AN onset (PA-post); new, pathological motivation for PA (PA-new); and high intensity PA (PA-high). Eating disorder psychopathology was measured via the Eating Disorder Examination Questionnaire (EDE-Q), and current PA (steps/day) with accelerometry. PA1-6 was also assessed in healthy controls (HCs). Using stepwise backward regression models, predictors of %mBMI change and LOS were examined. Compared with 22 HCs (age = 14.7 ± 1.3 years, %mBMI = 102.4 ± 12.1), 25 patients with AN (age = 15.1 ± 1.7 years, %mBMI = 74.8 ± 6.0) reported significantly higher PA1-6 (median, AN = 115 [interquartile range IQR = 75;200] min vs. HC = 68 [IQR = 29;105] min; p = 0.017). PA-post was 244 ± 323% higher than PA-pre. PA1-6 was directly associated with PA-pre (p = 0.001) but not with PA-post (p = 0.179) or change in PA-pre to PA-post (p = 0.735). Lower %mBMI gain was predicted by lower baseline %mBMI (p = 0.001) and more PA-high (p = 0.004; r2 = 0.604). Longer LOS was predicted by higher PA-pre (p = 0.003, r2 = 0.368). Self-reported PA may identify a subgroup of youth with AN at risk of less weight gain and prolonged LOS during inpatient treatment for AN.
Assuntos
Anorexia Nervosa , Exercício Físico , Pacientes Internados , Tempo de Internação , Autorrelato , Humanos , Anorexia Nervosa/terapia , Anorexia Nervosa/psicologia , Adolescente , Projetos Piloto , Feminino , Tempo de Internação/estatística & dados numéricos , Pacientes Internados/estatística & dados numéricos , Masculino , Resultado do Tratamento , Índice de Massa Corporal , HospitalizaçãoRESUMO
OBJECTIVE: Family-based treatment (FBT) for youth with anorexia nervosa (AN), has not been compared to inpatient, multimodal treatment (IMT). METHOD: Prospective, non-randomized pilot feasibility study of adolescents with AN receiving FBT (n = 31), and as a reference point for exploratory outcome comparisons IMT (n = 31), matched for baseline age and percent median BMI (%mBMI). Feasibility of FBT in youth fulfilling criteria for IMT was assessed via study recruitment and retention rates; acceptability via drop-out and caregiver strain; safety via adverse events; preliminary treatment effectiveness between groups was assessed via a change in %mBMI, AN psychopathology (Eating Disorder Examination-Questionnaire, EDE-Q), and hospital days, over 12 months with intent-to-treat, mixed models repeated measures analyses covering post-intervention usual care until 12 months. RESULTS: Taking into account that 8 FBT patients (25.8%) crossed over to IMT due to lack of weight gain or psychiatric concerns, FBT and IMT were similarly feasible, acceptable, and safe, apart from more physical antagonism toward others in FBT (p = .010). FBT lasted longer (median [interquartile range, IQR]; 33.6 [17.4, 49.9] vs. 17.3 [14.4, 24] weeks, p < .001), but required fewer hospital days than IMT (median, [IQR], FBT = 1 [0, 16] vs. IMT = 123 [101, 180], p < .001). Baseline comorbidity-adjusted changes over 12 months did not differ between groups in %mBMI (FBT = 12.6 ± 11.9 vs. IMT = 13.7 ± 9.1; p = .702) and EDE-Q global score (median, [IQR]; FBT = -1.2 [-2.3, 0.2] vs. IMT = -1.3 [-2.8, -0.4]; p = .733). DISCUSSION: Implementing FBT in this pilot study was feasible, acceptable, and safe for youth eligible for IMT according to German S3 guidelines. Non-inferiority of FBT versus IMT requires confirmation in a sufficiently large multicenter RCT. PUBLIC SIGNIFICANCE: This pilot study with 62 adolescent patients with anorexia nervosa demonstrated that for 2/3rd of patients eligible for a long hospitalization in the German health care system, outpatient, Family-based treatment (FBT) was a safe and feasible treatment alternative. Over 12 months, FBT lead to similar weight gain and reduction in eating disorder cognitions as inpatient treatment with fewer hospital days. This pilot study needs to be followed up by a larger, multicenter trial.
Assuntos
Anorexia Nervosa , Humanos , Adolescente , Anorexia Nervosa/terapia , Anorexia Nervosa/psicologia , Estudos de Viabilidade , Pacientes Internados , Projetos Piloto , Estudos Prospectivos , Terapia Familiar , Hospitalização , Resultado do Tratamento , Aumento de PesoRESUMO
Childhood leukemia (CL) is undoubtedly caused by a multifactorial process with genetic as well as environmental factors playing a role. But in spite of several efforts in a variety of scientific fields, the causes of the disease and the interplay of possible risk factors are still poorly understood. To push forward the research on the causes of CL, the German Federal Office for Radiation Protection has been organizing recurring international workshops since 2008 every two to three years. In November 2019 the 6th International Workshop on the Causes of CL was held in Freising and brought together experts from diverse disciplines. The workshop was divided into two main parts focusing on genetic and environmental risk factors, respectively. Two additional special sessions addressed the influence of natural background radiation on the risk of CL and the progress in the development of mouse models used for experimental studies on acute lymphoblastic leukemia, the most common form of leukemia worldwide. The workshop presentations highlighted the role of infections as environmental risk factor for CL, specifically for acute lymphoblastic leukemia. Major support comes from two mouse models, the Pax5+/- and Sca1-ETV6-RUNX1 mouse model, one of the major achievements made in the last years. Mice of both predisposed models only develop leukemia when exposed to common infections. These results emphasize the impact of gene-environment-interactions on the development of CL and warrant further investigation of such interactions - especially because genetic predisposition is detected with increasing frequency in CL. This article summarizes the workshop presentations and discusses the results in the context of the international literature.
Assuntos
Leucemia-Linfoma Linfoblástico de Células Precursoras , Animais , Criança , Predisposição Genética para Doença , Humanos , Camundongos , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Fatores de RiscoRESUMO
In situ follicular neoplasia (ISFN) is the earliest morphologically identifiable precursor of follicular lymphoma (FL). Although it is genetically less complex than FL and has low risk for progression, ISFN already harbors secondary genetic alterations, in addition to the defining t(14;18)(q32;q21) translocation. FL, in turn, frequently progresses to diffuse large B-cell lymphoma (DLBCL) or high-grade B-cell lymphoma (HGBL). By BCL2 staining of available reactive lymphoid tissue obtained at any time point in patients with aggressive B-cell lymphoma (BCL), we identified ten paired cases of ISFN and DLBCL/HGBL, including six de novo tumors and four tumors transformed from FL as an intermediate step, and investigated their clonal evolution using microdissection and next-generation sequencing. A clonal relationship between ISFN and aggressive BCL was established by immunoglobulin and/or BCL2 rearrangements and/or the demonstration of shared somatic mutations for all ten cases. Targeted sequencing revealed CREBBP, KMT2D, EZH2, TNFRSF14 and BCL2 as the genes most frequently mutated already in ISFN. Based on the distribution of private and shared mutations, two patterns of clonal evolution were evident. In most cases, the aggressive lymphoma, ISFN and, when present, FL revealed divergent evolution from a common progenitor, whereas linear evolution with sequential accumulation of mutations was less frequent. In conclusion, we demonstrate for the first time that t(14;18)+ aggressive BCL can arise from ISFN without clinically evident FL as an intermediate step and that during this progression, branched evolution is common.
Assuntos
Linfoma Folicular , Linfoma Difuso de Grandes Células B , Evolução Molecular , Centro Germinativo , Humanos , Linfoma Folicular/genética , Translocação GenéticaRESUMO
Fifty-five cases of t(14;18)- follicular lymphoma (FL) were genetically characterized by targeted sequencing and copy number (CN) arrays. t(14;18)- FL predominated in women (M/F 1:2); patients often presented during early clinical stages (71%), and had excellent prognoses. Overall, t(14;18)- FL displayed CN alterations (CNAs) and gene mutations carried by conventional t(14;18)+ FL (cFL), but with different frequencies. The most frequently mutated gene was STAT6 (57%) followed by CREBBP (49%), TNFRSF14 (39%), and KMT2D (27%). t(14;18)- FL showed significantly more STAT6 mutations and lacked MYD88, NOTCH2, MEF2B, and MAP2K1 mutations compared with cFL, nodal marginal zone lymphoma (NMZL), and pediatric-type FL (PTFL). We identified 2 molecular clusters. Cluster A was characterized by TNFRSF14 mutations/1p36 alterations (96%) and frequent mutations in epigenetic regulators, with recurrent loss of 6q21-24 sharing many features with cFL. Cluster B showed few genetic alterations; however, a subgroup with STAT6 mutations concurrent with CREBBP mutations/16p alterations without TNFRSF14 and EZH2 mutations was noted (65%). These 2 molecular clusters did not distinguish cases by inguinal localization, growth pattern, or presence of STAT6 mutations. BCL6 rearrangements were demonstrated in 10 of 45 (22%) cases and did not cluster together. Cases with predominantly inguinal presentation (20 of 50; 40%) had a higher frequency of diffuse growth pattern, STAT6 mutations, CD23 expression, and a lower number of CNAs, in comparison with noninguinal cases (5.1 vs 9.1 alterations per case; P < .05). STAT6 mutations showed a positive correlation with CD23 expression (P < .001). In summary, t(14;18)- FL is genetically a heterogeneous disorder with features that differ from cFL, NMZL, and PTFL.
Assuntos
Linfoma de Zona Marginal Tipo Células B , Linfoma Folicular , Criança , Variações do Número de Cópias de DNA , Feminino , Humanos , Linfoma Folicular/genética , MutaçãoAssuntos
Regulação da Temperatura Corporal/efeitos da radiação , Telefone Celular , Neoplasias Induzidas por Radiação/fisiopatologia , Estresse Fisiológico/efeitos da radiação , Animais , Temperatura Corporal/fisiologia , Temperatura Corporal/efeitos da radiação , Feminino , Masculino , Camundongos , Estresse Fisiológico/fisiologia , Fatores de TempoRESUMO
Anaplastic lymphoma kinase-positive (ALK+) anaplastic large-cell lymphoma (ALCL) is characterized by expression of oncogenic ALK fusion proteins due to the translocation t(2;5)(p23;q35) or variants. Although genotypically a T-cell lymphoma, ALK+ ALCL cells frequently show loss of T-cell-specific surface antigens and expression of monocytic markers. C/EBPß, a transcription factor constitutively overexpressed in ALK+ ALCL cells, has been shown to play an important role in the activation and differentiation of macrophages and is furthermore capable of transdifferentiating B-cell and T-cell progenitors to macrophages in vitro. To analyze the role of C/EBPß for the unusual phenotype of ALK+ ALCL cells, C/EBPß was knocked down by RNA interference in two ALK+ ALCL cell lines, and surface antigen expression profiles of these cell lines were generated using a Human Cell Surface Marker Screening Panel (BD Biosciences). Interesting candidate antigens were further analyzed by immunohistochemistry in primary ALCL ALK+ and ALK- cases. Antigen expression profiling revealed marked changes in the expression of the activation markers CD25, CD30, CD98, CD147, and CD227 after C/EBPß knockdown. Immunohistochemical analysis confirmed a strong, membranous CD147 (EMMPRIN) expression in ALK+ ALCL cases. In contrast, ALK- ALCL cases showed a weaker CD147 expression. CD274 or PD-L1, an immune inhibitory receptor ligand, was downregulated after C/EBPß knockdown. PD-L1 also showed stronger expression in ALK+ ALCL compared with ALK- ALCL, suggesting an additional role of C/EBPß in ALK+ ALCL in generating an immunosuppressive environment. Finally, no expression changes of T-cell or monocytic markers were detected. In conclusion, surface antigen expression profiling demonstrates that C/EBPß plays a critical role in the activation state of ALK+ ALCL cells and reveals CD147 and PD-L1 as important downstream targets. The multiple roles of CD147 in migration, adhesion, and invasion, as well as T-cell activation and proliferation suggest its involvement in the pathogenesis of ALCL.
Assuntos
Basigina/metabolismo , Proteína beta Intensificadora de Ligação a CCAAT/metabolismo , Regulação Neoplásica da Expressão Gênica/genética , Linfoma Anaplásico de Células Grandes/genética , Linfoma Anaplásico de Células Grandes/metabolismo , Receptores Proteína Tirosina Quinases/genética , Quinase do Linfoma Anaplásico , Antígenos CD/análise , Antígenos CD/genética , Antígenos CD/metabolismo , Basigina/análise , Basigina/genética , Proteína beta Intensificadora de Ligação a CCAAT/genética , Linhagem Celular Tumoral , Perfilação da Expressão Gênica , Técnicas de Silenciamento de Genes , Humanos , Linfonodos/química , Linfonodos/metabolismo , Linfoma Anaplásico de Células Grandes/química , Proteínas de Fusão Oncogênica/genéticaRESUMO
Pediatric-type follicular lymphoma (PTFL) is a B-cell lymphoma with distinctive clinicopathological features. Recently, recurrent genetic alterations of potential importance for its pathogenesis that disrupt pathways associated with the germinal center reaction (TNFRSF14, IRF8), immune escape (TNFRSF14), and anti-apoptosis (MAP2K1) have been described. In an attempt to shed more light onto the pathogenesis of PTFL, an integrative analysis of these mutations was undertaken in a large cohort of 43 cases previously characterized by targeted next-generation sequencing and copy number array. Mutations in MAP2K1 were found in 49% (20/41) of the cases, second in frequency to TNFRSF14 alterations (22/41; 54%), and all together were present in 81% of the cases. Immunohistochemical analysis of the MAP2K1 downstream target extracellular signal-regulated kinase demonstrated its phosphorylation in the evaluable cases and revealed a good correlation with the allelic frequency of the MAP2K1 mutation. The IRF8 p.K66R mutation was present in 15% (6/39) of the cases and was concomitant with TNFRSF14 mutations in 4 cases. This hot spot seems to be highly characteristic for PTFL. In conclusion, TNFRSF14 and MAP2K1 mutations are the most frequent genetic alterations found in PTFL and occur independently in most cases, suggesting that both mutations might play an important role in PTFL lymphomagenesis.
Assuntos
Regulação Neoplásica da Expressão Gênica , Fatores Reguladores de Interferon/genética , Linfoma Folicular/genética , MAP Quinase Quinase 1/genética , Proteína Quinase 1 Ativada por Mitógeno/genética , Proteína Quinase 3 Ativada por Mitógeno/genética , Membro 14 de Receptores do Fator de Necrose Tumoral/genética , Alelos , Carcinogênese/genética , Carcinogênese/metabolismo , Carcinogênese/patologia , Criança , Variações do Número de Cópias de DNA , Feminino , Perfilação da Expressão Gênica , Frequência do Gene , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Fatores Reguladores de Interferon/metabolismo , Linfoma Folicular/diagnóstico , Linfoma Folicular/metabolismo , Linfoma Folicular/patologia , MAP Quinase Quinase 1/metabolismo , Masculino , Análise em Microsséries , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Mutação , Fosforilação , Membro 14 de Receptores do Fator de Necrose Tumoral/metabolismoRESUMO
Palisaded neutrophilic and granulomatous dermatitis (PNGD) is characterized by erythematous papules or plaques on trunk or limbs and is frequently associated with rheumatologic, autoimmune, or hematologic malignancies. Histopathology shows interstitial granulomas composed of epitheloid histiocytes in the reticular dermis with surrounding foci of collagen degeneration and variable neutrophilic inflammation. We report 3 cases of generalized PNGD associated with chronic myelomonocytic leukemia (CMML), a myelodysplastic/myeloproliferative neoplasm, which may show a variety of cutaneous manifestations. SRSF2 P95 hotspot mutations, found in 40%-50% of CMML cases, were retrospectively detected in skin and bone marrow biopsies of all 3 patients, in 1 of them already 5 years before CMML diagnosis. Generalized PNGD may represent a type of cutaneous manifestation of CMML. Because diagnosis of CMML is frequently difficult in cases with isolated persistent monocytosis and minimal dysplasia in the bone marrow, patients with a generalized PNGD should be evaluated for the presence of hematologic disorders including CMML, ideally supported by mutational analyses.
Assuntos
Dermatite/diagnóstico , Granuloma/diagnóstico , Leucemia Mielomonocítica Crônica/diagnóstico , Neutrófilos/patologia , Pele/patologia , Idoso , Biomarcadores Tumorais/análise , Biomarcadores Tumorais/genética , Biópsia , Exame de Medula Óssea , Análise Mutacional de DNA , Dermatite/genética , Dermatite/imunologia , Dermatite/patologia , Feminino , Predisposição Genética para Doença , Granuloma/genética , Granuloma/imunologia , Granuloma/patologia , Humanos , Imuno-Histoquímica , Leucemia Mielomonocítica Crônica/genética , Leucemia Mielomonocítica Crônica/imunologia , Leucemia Mielomonocítica Crônica/patologia , Masculino , Pessoa de Meia-Idade , Mutação , Neutrófilos/imunologia , Fenótipo , Valor Preditivo dos Testes , Estudos Retrospectivos , Fatores de Processamento de Serina-Arginina/genética , Pele/imunologiaRESUMO
Pediatric-type follicular lymphoma (PTFL) is a variant of follicular lymphoma (FL) with distinctive clinicopathological features. Patients are predominantly young males presenting with localized lymphadenopathy; the tumor shows high-grade cytology and lacks both BCL2 expression and t(14;18) translocation. The genetic alterations involved in the pathogenesis of PTFL are unknown. Therefore, 42 PTFL (40 males and 2 females; mean age, 16 years; range, 5-31) were genetically characterized. For comparison, 11 cases of conventional t(14:18)(-) FL in adults were investigated. Morphologically, PTFL cases had follicular growth pattern without diffuse areas and characteristic immunophenotype. All cases showed monoclonal immunoglobulin (IG) rearrangement. PTFL displays low genomic complexity when compared with t(14;18)(-) FL (mean, 0.77 vs 9 copy number alterations per case; P <001). Both groups presented 1p36 alterations including TNFRSF14, but copy-number neutral loss of heterozygosity (CNN-LOH) of this locus was more frequently observed in PTFL (40% vs 9%; P =075). TNFRSF14 was the most frequently affected gene in PTFL (21 mutations and 2 deletions), identified in 54% of cases, followed by KMT2D mutations in 16%. Other histone-modifying genes were rarely affected. In contrast, t(14;18)(-) FL displayed a mutational profile similar to t(14;18)(+) FL. In 8 PTFL cases (19%), no genetic alterations were identified beyond IG monoclonal rearrangement. The genetic landscape of PTFL suggests that TNFRSF14 mutations accompanied by CNN-LOH of the 1p36 locus in over 70% of mutated cases, as additional selection mechanism, might play a key role in the pathogenesis of this disease. The genetic profiles of PTFL and t(14;18)(-) FL in adults indicate that these are two different disorders.
Assuntos
Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Linfoma Folicular/genética , Mutação/genética , Membro 14 de Receptores do Fator de Necrose Tumoral/genética , Adolescente , Adulto , Criança , Pré-Escolar , Cromossomos Humanos Par 14/genética , Cromossomos Humanos Par 18/genética , Células Clonais , Análise Citogenética , Variações do Número de Cópias de DNA/genética , Análise Mutacional de DNA , Éxons/genética , Feminino , Humanos , Hibridização in Situ Fluorescente , Perda de Heterozigosidade/genética , Linfoma Folicular/patologia , Masculino , Pseudolinfoma , Translocação Genética , Adulto JovemRESUMO
Vitreoretinal diffuse large B-cell lymphoma is a rare disorder, occurring as primary ocular disease or as secondary involvement by primary central nervous system lymphoma. It is usually diagnosed by cytologic, immunocytochemical, and molecular examination of vitreous aspirates. However, distinguishing vitreoretinal diffuse large B-cell lymphoma from uveitis remains difficult, and clonality analysis may be either unsuccessful or misleading. Diffuse large B-cell lymphoma arising in immune-privileged sites (eg, the central nervous system) shows a high frequency of MYD88 mutations. Therefore, we retrospectively assessed the frequency of MYD88 mutations in vitreoretinal lymphoma (VRL) and their diagnostic potential in 75 vitrectomy samples of 69 patients, and validated our results in a separate cohort (n = 21). MYD88 mutations were identified in 20 of 29 (69%) clinically, histologically, and molecularly confirmed VRL, including 6 cases of the test cohort initially diagnosed as reactive (3/6) or suspicious (3/6) for lymphoma. MYD88 mutations, especially L265P, are very frequent in VRL and their detection significantly improves the diagnostic yield of vitrectomy specimens.
Assuntos
Linfoma de Células B/diagnóstico , Mutação , Fator 88 de Diferenciação Mieloide/genética , Retina/patologia , Neoplasias da Retina/diagnóstico , Vitrectomia , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/genética , Biópsia por Agulha , Estudos de Coortes , Técnicas de Diagnóstico Oftalmológico , Feminino , Frequência do Gene , Humanos , Linfoma de Células B/genética , Linfoma de Células B/patologia , Masculino , Pessoa de Meia-Idade , Neoplasias da Retina/genética , Neoplasias da Retina/patologia , Vitrectomia/métodos , Adulto JovemAssuntos
Calreticulina/genética , Proteínas de Fusão bcr-abl/genética , Leucemia Mielogênica Crônica BCR-ABL Positiva/etiologia , Mutação/genética , Trombocitemia Essencial/complicações , Trombocitemia Essencial/genética , Translocação Genética/genética , Adulto , Humanos , Leucemia Mielogênica Crônica BCR-ABL Positiva/patologia , Masculino , Prognóstico , Trombocitemia Essencial/patologiaRESUMO
Recurrent mutations in MYD88 have been identified in >90% of lymphoplasmacytic lymphoma (LPL). Recently, WHIM (warts, hypogammaglobulinaemia, infections, myelokathexis) syndrome-like mutations in CXCR4 have been described in 28% of LPL cases, and seem to impact clinical presentation and response to therapy. We investigated the presence of the MYD88 L265P mutation in 90 decalcified, formalin-fixed, paraffin-embedded (FFPE) bone marrow (BM) biopsies, including 51 cases of LPL, 14 cases of B-cell chronic lymphocytic leukaemia (CLL), 13 cases of marginal zone lymphoma (MZL) and 12 normal controls. In addition, the C-terminal domain of CXCR4 was sequenced in LPL cases. MYD88 L265P was found in 49/51 (96%) LPL cases and in 1/13 (7·6%) MZL (splenic type), whereas all CLL samples remained negative. The two MYD88 wild type LPL cases were associated with cold agglutinin disease. Mutations in CXCR4 were detected in 17/47 (36·2%) LPL cases, which showed a higher extent of BM infiltration and lower leucocyte counts (P = 0·02), haemoglobin (P = 0·05) and platelet counts (P = 0·01). In conclusion the detection of MYD88 L265P mutation in FFPE samples is reliable and useful for subtyping small B-cell lymphomas in BM biopsies. In addition, the presence of CXCR4 mutations identifies a subgroup of LPL patients with higher disease activity.
Assuntos
Mutação , Fator 88 de Diferenciação Mieloide/genética , Receptores CXCR4/genética , Macroglobulinemia de Waldenstrom/diagnóstico , Macroglobulinemia de Waldenstrom/genética , Idoso , Idoso de 80 Anos ou mais , Substituição de Aminoácidos , Medula Óssea/patologia , Feminino , Humanos , Linfoma de Células B/genética , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Prognóstico , Sensibilidade e EspecificidadeRESUMO
Follicular lymphoma (FL) is characterized by the translocation t(14;18)(q32;q21) resulting in constitutive overexpression of BCL2. However, in 10% to 15% of FL grade 1/2, immunohistochemical staining for BCL2 remains negative. To analyze the incidence of BCL2 negativity and the underlying molecular mechanisms in FL grade 1/2, BCL2 expression was investigated with 3 antibodies (clones 100D5, E17, SP66). The presence of a break in the BCL2 locus was determined by fluorescence in situ hybridization. The region of the BCL2 gene where the epitope of the standard BCL2 antibody resides was sequenced. Twenty-two (9.2%) of 240 identified cases of FL grade 1/2 were negative with the standard BCL2 antibody. Of these, 12 cases (55%) carried a break in the BCL2 gene locus, which, in all but one case, correlated with BCL2 expression using the alternative antibodies E17 and SP66 and with missense mutations of BCL2. Ten (45%) of the 22 cases had an intact BCL2 gene locus; 2 cases carried a BCL6/IGH translocation. All 10 cases were negative for the E17/SP66 antibodies and showed a wild-type sequence of BCL2. Six of these showed an aberrant phenotype, with CD10 negativity (30%) or CD23 expression (30%). In summary, the alternative E17/SP66 antibodies identify 2 immunohistochemically and genetically distinct subgroups of BCL2-"negative" FL grade 1/2.