Three New Ranidae Mitogenomes and the Evolution of Mitochondrial Gene Rearrangements among Ranidae Species

Various types of gene rearrangements have been discovered in the mitogenoes of the frog family Ranidae. In this study, we determined the complete mitogenome sequence of three Rana frogs. By combining the available mitogenomic data sets from GenBank, we evaluated the phylogenetic relationships of Ranidae at the mitogenome level and analyzed mitogenome rearrangement cases within Ranidae. The three frogs shared an identical mitogenome organization that was extremely similar to the typical Neobatrachian-type arrangement. Except for the genus Babina, the monophyly of each genus was well supported. The genus Amnirana occupied the most basal position among the Ranidae. The [Lithobates ＋ Rana] was the closest sister group of Odorrana. The diversity of mitochondrial gene arrangements in ranid species was unexpectedly high, with 47 mitogenomes from 40 ranids being classified into 10 different gene rearrangement types. Some taxa owned their unique gene rearrangement characteristics, which had significant implication for their phylogeny analysis. All rearrangement events discovered in the Ranidae mitogenomes can be explained by the duplication and random loss model.

Bcl-2 GENE REARRANGEMENT DETERMINED BY PCR AS AMEAN TO DETECT MINIMAL RESIDUAL DISEASE INMALIGNANT LYMPHOMAS

Objective: To develop a sensitive method to detect minimal residual disease and to elucidate the significance of bcl-2 gene rearrangement in diagnosis and treatment of malignant lymphoma. Methods: Using polymerase chain reaction (PCR) to detect bcl-2 gene rearrangement and using serial dilution method to define the sensitivity of PCR. Results: In 9 different malignant lymphoma cell lines, Su-DHL-4 and Su-DHL-6 were shown bcl-2(MBR)/JH rearrangement, the sensitivity of PCR was 1:105. In 16 patients with follicular lymphoma, the peripheral blood and bone marrow were PCR positive in 4 cases both at initial diagnosis and after complete remission. Conclusion: Detection of bcl-2 gene rearrangement by PCR provides a sensitive and specific assay of minimal residual disease. It is helpful to improve staging of disease, prognosis and evaluation of the treatment results.

Epidemiological Surveillance: Genetic Diversity of Rotavirus Group A in the Pearl River Delta, Guangdong, China in 2019

Objective This study aimed to understand the epidemic status and phylogenetic relationships of rotavirus group A(RVA)in the Pearl River Delta region of Guangdong Province,China.Methods This study included individuals aged 28 days–85 years.A total of 706 stool samples from patients with acute gastroenteritis collected between January 2019 and January 2020 were analyzed for 17 causative pathogens,including RVA,using a Gastrointestinal Pathogen Panel,followed by genotyping,virus isolation,and complete sequencing to assess the genetic diversity of RVA.Results The overall RVA infection rate was 14.59%(103/706),with an irregular epidemiological pattern.The proportion of co-infection with RVA and other pathogens was 39.81%(41/103).Acute gastroenteritis is highly prevalent in young children aged 0–1 year,and RVA is the key pathogen circulating in patients 6–10 months of age with diarrhea.G9P[8](58.25%,60/103)was found to be the predominant genotype in the RVA strains,and the 41 RVA-positive strains that were successfully sequenced belonged to three different RVA genotypes in the phylogenetic analysis.Recombination analysis showed that gene reassortment events,selection pressure,codon usage bias,gene polymorphism,and post-translational modifications(PTMs)occurred in the G9P[8]and G3P[8]strains.Conclusion This study provides molecular evidence of RVA prevalence in the Pearl River Delta region of China,further enriching the existing information on its genetics and evolutionary characteristics and suggesting the emergence of genetic diversity.Strengthening the surveillance of genotypic changes and gene reassortment in RVA strains is essential for further research and a better understanding of strain variations for further vaccine development.

Progress in clinical diagnosis and treatment of colorectal cancer with rare genetic variants

Targeted therapy is crucial for advanced colorectal cancer(CRC) positive for genetic drivers. With advances in deep sequencing technology and new targeted drugs, existing standard molecular pathological detection systems and therapeutic strategies can no longer meet the requirements for careful management of patients with advanced CRC. Thus, rare genetic variations require diagnosis and targeted therapy in clinical practice. Rare gene mutations, amplifications, and rearrangements are usually associated with poor prognosis and poor response to conventional therapy. This review summarizes the clinical diagnosis and treatment of rare genetic variations, in genes including erb-b2 receptor tyrosine kinase 2(ERBB2), B-Raf proto-oncogene, serine/threonine kinase(BRAF), ALK receptor tyrosine kinase/ROS proto-oncogene 1, receptor tyrosine kinase(ALK/ROS1), neurotrophic receptor tyrosine kinases(NTRKs), ret proto-oncogene(RET), fibroblast growth factor receptor 2(FGFR2), and epidermal growth factor receptor(EGFR), to enhance understanding and identify more accurate personalized treatments for patients with rare genetic variations.

γANDδCHAIN GENE REARRANGEMENT OF T CELL RECEPTOR IN ACUTE LYMPHOBLASTIC LEUKEMIA

The immunophenotype, rearrangements of T cell receptor(TCR) γ andδchain genes as well as the immunoglobulinheavy chain (IgH)gene were studied in 37 cases ofmorphologically defined acute lymphoblastic leukemia (ALL).According to the expression of differentiation antigens, 8 caseswere classified as T-ALL, 26 B lineage ALL, 2 acute un-differentiated leukemia (AUL) and myeloid phenotype. An or-der of TCR gene rearrangements was observed in T-ALL,with the rearrangement of δgene preceding that of γgene.Both genes were also found frequently rearranged and / or de-leted in high proportions of the ALL of B cell lineage. Howev-er, the patterns of gene rearrangements were somewhat differ-ent between the T and B lineage ALLs. In contrast, the lgHgene rearrangements were observed only in the B lineage ALL.The immunogenotype analysis of ALL proved to be a usefulmarker of the clonality and provided us with important informa-tion on early human lymphoid differentiation. We concludethat the determination of T

Mitochondrial gene rearrangement within genus Gasteruption(Hymenoptera: Evanioidea: Gasteruptiidae)

The complete mitochondrial genome of the Gasteruption parvicollarium Enderlein （GenBank accession number： KR270643） was sequenced in the study. Totally 17 009 bp sequence was determined with an A＋T content of 83.81%, including full set of typical animal mitochondrial genes. Two protein-coding and 10 tRNA genes as well as the A＋T-rich region were rearranged compared with the putative ancestral arrangement of insects. Most of the rearranged genes were located in the ancestral region of trnl-trnQ-trnM-nad2-trn W-trnC-trn Y- coxl-trnL2. The other rearranged genes are trnN and trnS1 located in the tRNA cluster trnA- trnR-trnN-trnSl-trnE-trnF and trnS2 located between cob and nadl. Remote inversion is dominant rearrangement event in G. parvicollarium mitochondrial genome, involving two protein-coding and 8 tRNA genes. Compared with the other mitochondrial genome reported in the same genus of Gasteruption, the inverted trnN was translocated to the tRNA cluster between cox1 and nad2 in G. parvicollarium. This is the first report of mitochondrial gene rearrangement occurred within genus of Hymenoptera. Our study points to a recently occurred gene rearrangement event in the Gasteruption species.

THE RELATIONSHIP BETWEEN NON-HODGKIN'S LYMPHOMA AND THE GENE REARRANGEMENT

Objective: To investigate the pattern of clonal rearrangement of immunoglobulin heavy chain gene (IGH) and T cell receptor γ gene (TCRγ) of Non Hodgkin's lymphoma (NHL) Methods: Bone marrow smears of 211 patients of NHL were detected by PCR, the rearranged IGH and TCRγ gene was amplified using oligonucleotide primers Results: The clonal rearrangement of IGH gene was detectable in 51 2% (108/211); the clonal rearrangement of TCRγ gene was detectable in 21 3% (45/211); both IGH and TCRγ was detectable in 5 7% (12/211); no clonal rearrangement in 21 8% (46/211) And compared clonal gene rearrangement with pathological type and primary site of tumor Ten patients of NHL were investigated serially 5/10 patients still had clonal gene rearrangement at clinical complete remission Conclusion: It demonstrated that this assay may be useful in monitoring the minimal residual disease (MRD) and in evaluating effectiveness of therapy

T-CELL RECEPTOR GENE REARRANGEMENT ANALYSIS IN THE PRIMARY CUTANEOUS T-CELL LYMPHOMA

Object: The present paper is to evaluate the significance of T cell receptor (TCR) gene rearrange ments in primary cutaneous T cell lymphomas (PCTCL) as detected by analysis of Southern Blot (SBA) and polymerase chain reaction (PCR). Patients and Methods: Skin specimens and peripheral blood samples were taken from 44 patients with PCTCL, including 30 patients with mycosis fungoides (MF), 2 patients with Sezary's syndrome (SS), and 12 patients with PCTCL other than MF and SS (PNCTCL). 11 patients with a presumptive diagnosis of MF, 23 patients with lymphoproliferative dermatoses including lymphomatoid papulosis (LyP) and 8 patients with benign cutaneous lymphoid infiltrates were simultaneously studied by the amplification of junctional V (variable) J (joining) sequences of the rearranged TCRγ genes by PCR(TCRγPCR) and the analysis of TCRb chain genes by SBA(TCRβSBA) for detection of clonal gene rearrangements (GR). One lymph node specimen of a case with MF IIA was also detected by TCRγ PCR and TCRβSBA. Results: In MF, GR were detected by TCRγPCR and TCRβSBAb in 83.3 85.7% and 66.7% 71.4% of skin specimens of cases IIA IIB and in 57.1% 70.0% and 14.3% 10.0% of those of cases IA IB, respectively. GR were seen in 66.7% 71.4% and 33.3% 43.0.% of blood samples of cases IIA IIB, and 42.9% 40.0% and 0 10.0% of those of cases IA IB, respectively. GR was confirmed by TCRγ PCR and TCRβSBA in one lymph node showing dermato pathic lymphadenopathy of a case with MF IIA. In 11 patients of clinically suspected MF, GR were present in skin specimens of 5 cases (45.4%) and in blood samples of 3 cases ( 27.3% ) by TCRγ PCR. In PNCTCL, GR were found in 9 skin specimens (90.0%) from 10 patients detected by TCRγ PCR and in 6 skin specimens (75.0%) from 8 patients detected by TCRβSBA. GR were also seen in 6 blood samples (72.8%) from 11 patients detected by TCRγ PCR, and in 7 blood samples (70.0%) from 10 patients by TCRβSBA. In SS and LyP, GR were detected by TCRγ PCR and TCRβSBA in each of the two skin specimens of two cases with LyP and in each of the two blood samples of two cases with SS. GR were seen in one skin specimen of one case with SS and one blood sample of one case with LyP detected by TCRγPCR. Conclusions: This study demonstrated that TCRγ PCR is a rapid, more sensitive tool than TCRβSBA, can be used in the analysis of T cell clonality in skin, lymph node and blood samples of patients with PCTCL and indicated that this method forms a useful supplement to other methods for diagnosis of early and suspected MF, confirmation of PNCTCL and determination of extracutaneous involvement of lymph node and blood.

Detection of Immunoglobulin Heavy China and T Cell Receptorγ Gene Rearrangement in Lymph Node Aspirates with PCR:Diagnostic Significance for Lymphoproliferative Disorders

Lymph node aspirates of 17 cases with enlarged superficial or isceral lymph nodes were detected for immunoglobulin heavy chain gene rearrangement (IgHRA) and T cell rcceptor γ gene rearrangement (TCRγRA) bypolymerase chain reaction (PCR). Combining with clinical data, pathologic diagnosis and immunophenotapy, we analyse the results as follows: 5 cases with nonlymphoid cancers and 3 cases with reactive lymphadenopathy do not present two kinds of clone gene rearrangements.5 out of 7 cases with NHL show clone gene rearrangements (IgH 3 cases, TCRY 2cases),two kinds of monoclonal band(100-120bp for IgHRA and 170-230bp for TCRγRA) were observed after electrophoresis of amplified DNA products. One case whose clinical sitcaion accorded with features of lymphoma was diagnosed as granulomatous lymphadenitis by pathologist, after gene rearaangement clone TCRγRA was detected,a correct diaguosis as NHL was made then. The significance of detecting the two kinds of gene rearrangement for clinical application and the limitations in diagnosis of lymphoproliferative disorders was discussed.

Two complete mitogenomes of Ocypodoidea(Decapoda: Brachyura), Cleistostoma dilatatum(Camptandriidae) and Euplax sp.(Macrophthalmidae) and its phylogenetic implications

Complete mitochondrial genomes(mitogenomes) can provide useful information for phylogenetic relationships,gene rearrangement, and molecular evolution. In the present study, two newly sequenced mitogenomes of Ocypodoidea(Cleistostoma dilatatum and Euplax sp.) were reported for the first time, which are 15 444 bp and16 129 bp in length, respectively. Cleistostoma dilatatum is the first species in the family Camptandriidae whose complete mitogenome was sequenced. Each mitogenome contains an entire set of 37 genes and a putative control region, but their gene arrangements are largely different. Tandem duplication and random loss model is proposed to account for their gene arrangements. Comparative genomic analyses of 19 mitogenomes clustering in one branch reveal that 18 of them shared the same gene rearrangement, while that of C. dilatatum mitogenome was consistent with the ancestral gene arrangement of Brachyura. The dN/dS ratio analysis shows that all PCGs are evolving under purifying selection. Phylogenetic analyses show that all Macrophalmidae species cluster together as a group, and then form a sister clade with Camptandriidae. Moreover, the polyphyly of three superfamilies(Ocypodoidea, Eriphioidea, and Grapsoidea) is reconfirmed. These findings help to confirm the phylogenetic position of Camptandriidae, as well as provide new insights into the phylogeny of Brachyura.

Comparative mitochondrial genome analysis of Cynoglossidae(Teleost:Pleuronectiformes)and phylogenetic implications

Generally,a teleostean group(e.g.,family or genus)owns one type or a set of similar mitochondrial gene arrangement.It is interesting,however,that four different types of gene arrangement have been found in the mitochondrial genome(mitogenome)of Cynoglossidae species.So far,the possible mechanisms of mitogenomic gene rearrangement and its potential implications have aroused widespread attention and caused lots of controversy.Here,a total of 21 Cynoglossidae mitogenomes and a newly sequenced mitogenome of Cynoglossus puncticpes(Pleuronectiformes:Cynoglossidae)were compared.The length ranges from 16417 bp to 18369 bp,which is mainly caused by the length heteroplasmy of control region(CR).Further analysis reveals that the difference of tandem repeats acts as a determining factor resulting in the length heterogeneity.Like most gene rearrangements of Cynoglossinae mitogenomes,tRNA-Gln gene encoded by the L-strand has translocated to the H-strand(Q inversion),accompanied by the translocation of CR in C.puncticpes mitogenome.The typical IQM order(tRNA-Ile-Gln-Met)changed to QIM order.Tandem duplication/random loss and mitochondrial recombination were accepted as the most possible models to account for the rearrangements in C.puncticpes mitogenome.Phylogenetic trees showed a strong correlation between the gap spacer in the rearranged QIM area and phylogeny,which provides a fresh idea for phylogenetic studies in future.

STUDY ON THE RFLPs AND AMPLICATION AND REARRANGEMENT OF THE TRANSFORMING GENES IN PRIMARY HEPATIC CARCINOMA, GASTRIC CARCINOMA AND BRAIN TUMOR WITH SIX HUMAN ONCOGENE PROBES

By using c-Ha-ras-1, N-ras Wigler (left sequence) and P52C.(right sequence), c-sis, v-erbB, c-myc and v-fos oncogenes as probes, restriction fragment length polymorphisms (RFLPs) of tumor tissue DNAs of 95 patients with gastric carcinoma, primary hepatic carcinoma and brain tumor, and those of 90 normal individuals were studied with the techniques of Southern blot and dot blot. Gene amplification and recombination were also examined in some tumors simultaneously. Some alleles of oncogene are reported in Chinese population for the first time. Moreover, the characteristic frequency of some "rare" alleles and genotypes occurred in some tumor samples is significantly higher than that occured in normal individuals. Pedigree analysis for 2 patients showed that some "rare" alleles are also abandant. Besides, gene amplification and recombination were found in some tumors.

Comparative analyses of mitogenomes in the social bees with insights into evolution of long inverted repeats in the Meliponini

The insect mitogenome is typically a compact circular molecule with highly conserved gene contents.Nonetheless,mitogenome structural variations have been reported in specific taxa,and gene rearrangements,usually the tRNAs,occur in different lineages.Because synapomorphies of mitogenome organizations can provide information for phylogenetic inferences,comparative analyses of mitogenomes have been given increasing attention.However,most studies use a very few species to represent the whole genus,tribe,family,or even order,overlooking potential variations at lower taxonomic levels,which might lead to some incorrect inferences.To provide new insights into mitogenome organizations and their implications for phylogenetic inference,this study conducted comparative analyses for mitogenomes of three social bee tribes(Meliponini,Bombini,and Apini)based on the phylogenetic framework with denser taxonomic sampling at the species and population levels.Comparative analyses revealed that mitogenomes of Apini and Bombini are the typical type,while those of Meliponini show diverse variations in mitogenome sizes and organizations.Large inverted repeats(IRs)cause significant gene rearrangements of protein coding genes(PCGs)and rRNAs in Indo-Malay/Australian stingless bee species.Molecular evolution analyses showed that the lineage with IRs have lower dN/dS ratios for PCGs than lineages without IRs,indicating potential effects of IRs on the evolution of mitochondrial genes.The finding of IRs and different patterns of gene rearrangements suggested that Meliponini is a hotspot in mitogenome evolution.Unlike conserved PCGs and rRNAs whose rearrangements were found only in the mentioned lineages within Meliponini,tRNA rearrangements are common across all three tribes of social bees,and are significant even at the species level,indicating that comprehensive sampling is needed to fully understand the patterns of tRNA rearrangements,and their implications for phylogenetic inference.

Detection of BCL2-IGHrearrangement on paraffin-embedded tissue sections obtained from a small submucosal tumor of the rectum in a patient with recurrent follicular lymphoma

A 59-year-old woman was admitted to our hospital because of recurrent follicular lymphoma(FL).Colonoscopic examination revealed a rectal submucosal tumor(SMT)without any erosions and ulcers.In this patient,it was difficult to distinguish non-Hodgkin's lymphoma(NHL)invasion from other disorders of the colon including carcinoid tumor merely based on endoscopic findings.Histopathologic and immunohistochemical studies on biopsy specimens showed an infiltration of atypical lymphocytes that were positive for CD20 and BCL2 but negative for UCHL-1.Fluorescence in situ hybridization on paraffin-embedded tissue sections (T-FISH)identified a translocation of BCL2 with IGHgene. Based on these findings,the tumor was defined as an invasion of FL.T-FISH method is useful for the detection of a monoclonality of atypical lymphocytes in an SMT of the gastrointestinal tract,and particularly for the detection of chromosomal translocations specific to lymphoma subtypes.

Comparative mitochondrial genome analysis of Varunidae and its phylogenetic implications

Complete mitochondrial genomes(mitogenomes)can indicate phylogenetic relationships,as well as useful information for gene rearrangement mechanisms and molecular evolution.Currently,the phylogenetic location of the genus Varuna(Brachyura:Varunidae)has not been well resolved mainly because of limited representatives(only two extant species).Here,we determined a new mitogenome of this genus(Varuna litterata)and added the published mitogenomes to reconstruct the phylogeny of Varunidae.The 16368-bp mitogenome contains the entire set of 37 genes and a putative control region.The characteristics of this newly sequenced mitogenome were described and compared with the other 15 Varunidae mitogenomes.All 16 analyzed mitogenomes have identical gene order and similar molecular features.The sliding window and genetic distance analyses demonstrate highly variable nucleotide diversity,with comparatively low variability of COI and COII,and high variability of ND6.The nonsynonymous/synonymous substitution rates(dN/dS ratio)analysis shows that all 13 PCGs are under purifying selection and ATP8 gene evolves under the least selective pressure.Twelve tRNA genes,two rRNAs,one PCG,and the putative control region are found to be rearranged with respect to the pancrustacean ground pattern gene order.Tandem duplication/random loss model is adopted to explain the large-scale gene rearrangement events occurring in Varunidae mitogenomes.Phylogenetic analyses show that all Varunidae species are placed into one group,and form a sister clade with Macrophthalmidae.Nevertheless,the phylogenetic relationships within Varunidae are not completely consistent based on the two different datasets used in this study.These findings will contribute to a better understanding of gene rearrangement and molecular evolution in Varunidae mitogenomes,as well as provide insights into the phylogenetic studies of Brachyura.

Comparative mitochondrial genome analysis of Sesarmidae and its phylogenetic implications

Here,we sequenced the complete mitogenome of Parasesarma eumolpe(Brachyura:Grapsoidea:Sesarmidae)for the first time.The characteristics of this newly sequenced mitogenome were described and compared with other Sesarmidae species.The 15646-bp mitogenome contains 13 protein-coding genes(PCGs),two ribosomal RNA genes(r RNAs),22 transfer RNA genes(t RNAs),and an A-T rich region.All of the PCGs are initiated by the start codon ATN and terminated by the standard TAN codon or an incomplete T.The pairwise Ka/Ks ratio analysis shows that all 13 PCGs are under purifying selection,whereas the ATP8 gene is an outlier,with pairwise comparison values ranging from neutral selection(0.000)to positive selection(1.039).The gene arrangement of P.eumolpe compared with ancestral Decapoda shows the translocation of two t RNAs(t RNA-His and t RNA-Gln),which is identical to other Sesarmidae species.Phylogenetic analyses show that all Sesarmidae species are placed into one group,and the polyphyly of Eriphioidea,Ocypodoidea,and Grapsoidea is well supported.The relationship between gaps in the QIM region and the phylogeny of Sesarmidae is analyzed.It is obvious that both the G5(the gap between Q and I)and G6(the gap between I and M)decrease progressively with the evolution process.These results will help to better understand the genomic evolution within Sesarmidae and provide insights into the phylogeny of Brachyura.

BCL-1 Rearrangement in Acute Lymphocytic Leukemia and Its Clinical Significance

BCL 1 rearrangement (BCL 1/IgH gene rearrangement) in acute lymphocytic leukemia and its clinical significance was investigated. In 38 patients with acute lymphocytic leukemia (ALL), the genomic DNA of mononuclear cells isolated from peripheral blood and bone marrow was amplified by using hemi nested polymerase chain reaction (PCR) technique and the expression of cycline D1 protein of mononuclear cells was detected by using immunohistochemical method. Ten patients with acute granulocytic leukemia, 2 with chronic granulocytic leukemia and 10 with normal bone marrow served as control group. The results showed that BCL 1 rearrangement was detectable in 3 of 38 ALL patients (7.9 %) and cyclin D1 protein positive expression was detected in 4 ALL patients (10 5 %). Three ALL patients with BCL 1 rearrangement were all B cell leukemia (B ALL) and accompanied by cyclin D1 protein expression. No BCL 1/IgH rearrangement or cyclin D1 protein expression was detected in 12 patients with granulocytic leukemia and 10 cases of normal bone marrow. Leukocyte counts in peripheral blood of B ALL patients with BCL 1 rearrangement and(or) cyclin D1 protein expression were significantly increased and the patients had bad reaction to chemotherapy. It was concluded that: 1) BCL 1/IgH gene rearrangement were detected in acute B lymphocytic leukemia; 2) B ALL patients with BCL 1 rearrangement and(or) cyclin D1 protein expression had poor prognosis.

Applications of Fluorescence in Situ Hybridization (FISH) for Detecting Genetic Changes in Hematological Malignancies

Fluorescence in situ hybridization (FISH) has become an important tool both for defining initial chromosomal abnormalities within a disease process, and for monitoring response to therapy as well as minimal residual disease. We report the results of interphase FISH (iFISH) analysis of 92 patients. We have used five different FISH probes to detect common cytogenetic rearrangements associated with hematological malignancies. A total of 83 patients were screened for BCR/ABL gene rearrangements. Displayed iFISH patterns of BCR/ABL gene rearrangements in 37.3% of patients (31/83) ranged between 10% to 98%. In addition, while 3 patients and one patient with AML showed t(15;17) (12.5%) and inv(16;16) (8.3%) respectively, t(8;21) was not found. Furthermore, secondary chromosomal aberrations (6.5% of all cases) were clearly non random in the present study. The diagnosis of BCR/ABL gene rearrangements are likely become an important tool for the monitoring of therapies in patients with CML. Atypical patterns also may have clinical prognostic implications. Further studies in larger groups of patients are needed in order to elucidate the role of AML1/ETO, PML/RARA, CBFB and p53, and to identify the specific chromosomal regions and interacting genes involved in this process.

B-cell clonality in the liver of hepatitis C virus-infected patients

AIM:The association of hepatitis C virus(HCV) infection with typeⅡmixed cryoglobulinemia is well established,but the role of HCV in B-cell lymphoma remains controversial.In patients with HCV infection,B-cell clonal expansions have been detected in peripheral blood and bone marrow,and a high prevalence of B-cell non-Hodgkin's lymphomas has been documented.Liver biopsies in chronic HCV infection frequently show portal lymphoid infiltrates with features of B follicles,whose clonality has not yet been investigated.The object of this study was to determine the frequency of liver-infiltrating monoclonal B-cells in 40 patients with HCV infection.METHODS:Eight hundred and forty-eight patients were studied prospectively,including 40 HCV-positive patients and 808 patients with chronic hepatitis B virus(HBV)infection.Immunohistochemical study for B-and T-cell markers was performed on the paraffin-embedded liver tissue sections.The clonality of lymphoid B-cells was tested using a polymerase chain reaction(PCR)approach designed to identify immunoglobulin heavy chain gene(IgH) rearrangements.RESULTS:Liver-infiltrating monoclonal B-cells were detected in the liver for 4(10%)of 40 HCV-positive patients but were present in only 3(0.37%)of 808 liver biopsy specimens with chronic HBV infection.Chi-square testing showed that the monoclonal B-cells infiltration in the liver was more frequent in the HCV-infected patients(P=0.000).A clonal IgH rearrangement was detected in 5(71.4%)of 7 liver biopsy specimens with monoclonal B-cells infiltration.In 2 of 5 patients with both a clonal B-cell expansion and monoclonal B-cells infiltration in the liver,a definite B-cell malignancy was finally diagnosed.CONCLUSION:Liver-infiltrating monoclonal B-cells are detected in the liver of patients with chronic HCV and HBV infection.A high percentage of patients with monoclonal B-cells infiltration and B-cell clonality in the liver were finally diagnosed as having a definite B-cell malignancy.

Rearrangement and expression of the immunoglobulin μ-chain gene in human myeloid cells

Immunoglobulin （Ig）, a characteristic marker of B cells, has been reported to be expressed in epithelial cells, with a suggested role in their growth and survival. We have previously reported that IgG heavy chain is expressed in acute myeloid leukemia （AML）, but not in the monocytes or neutrophils from patients with non-hematopoietic neoplasms or healthy controls. In the present study, we assessed IgM heavy chain expression and repertoire in human myeloid cells. We detected VHIzDJHp- rearrangement and expression in 7/7 AML cell lines, 7/14 primary myeloblasts from AML patients, and interestingly, 8/20 monocytes and 3/20 neutrophils from patients with non-hematopoietic neoplasms and healthy individuals. We also found evidence of somatic hypermutation of the variable （V） gene segments in AML-derived IgM gene rearrangements but not in IgM from monocytes or neutrophils from patients with non-hematopoietic neoplasms and healthy individuals. Furthermore, IgM VH^DJH~ gene rearrangements in AML cell lines, primary myeloblasts, and monocytes and neutrophils from patients with non-hematopoietic neoplasms showed a restricted V usage and repertoire, whereas the VH^DJH~ gene rearrangements in monocytes and neutrophils from healthy individuals displayed more diversity. Anti-human IgM inhibited cell proliferation, but did not induce apoptosis in AML cell lines. Our findings suggest that AML-derived IgM might be a novel AML-related molecule that is involved in leukemogenesis and AML progression and might serve as a useful molecular marker for designing targeted therapy and monitoring minimal residual disease.