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PubMed2022

High early death rates, treatment resistance, and short survival of Black adolescents and young adults with AML.

Survival of patients with acute myeloid leukemia (AML) is inversely associated with age, but the impact of race on outcomes of adolescent and young adult (AYA; range, 18-39 years) patients is unknown. We compared survival of 89 non-Hispanic Black and 566 non-Hispanic White AYA patients with AML treated on frontline Cancer and Leukemia Group B/Alliance for Clinical Trials in Oncology protocols. Samples of 327 patients (50 Black and 277 White) were analyzed via targeted sequencing. Integrated genomic profiling was performed on select longitudinal samples. Black patients had worse outcomes, especially those aged 18 to 29 years, who had a higher early death rate (16% vs 3%; P=.002), lower complete remission rate (66% vs 83%; P=.01), and decreased overall survival (OS; 5-year rates: 22% vs 51%; P<.001) compared with White patients. Survival disparities persisted across cytogenetic groups: Black patients aged 18 to 29 years with non-core-binding factor (CBF)-AML had worse OS than White patients (5-year rates: 12% vs 44%; P<.001), including patients with cytogenetically normal AML (13% vs 50%; P<.003). Genetic features differed, including lower frequencies of normal karyotypes and NPM1 and biallelic CEBPA mutations, and higher frequencies of CBF rearrangements and ASXL1, BCOR, and KRAS mutations in Black patients. Integrated genomic analysis identified both known and novel somatic variants, and relative clonal stability at relapse. Reduced response rates to induction chemotherapy and leukemic clone persistence suggest a need for different treatment intensities and/or modalities in Black AYA patients with AML. Higher early death rates suggest a delay in diagnosis and treatment, calling for systematic changes to patient care.

Adolescent↗
PubMed2026

Familial lymphoma and genetic predisposition: an updated review.

BACKGROUND: Several factors contribute to the development of malignant lymphomas including environmental exposures, bacterial and viral infections, as well as familial and genetic factors. MAIN BODY: Numerous somatic variants are involved in lymphomagenesis, and an increasing number of germline variants predisposing patients to lymphoid neoplasm have been identified. Although most lymphomas arise sporadically, epidemiological studies have linked a familial history of lymphomas and other hematological tumors with an increased lymphoma risk. Although rare, familial clustering of malignant lymphoma is well documented, and the constellations suggest inherited risk factors. Recent technological advancements have improved our ability to identify genetic factors associated with lymphoma that overall lead to a better understanding of genetic susceptibility for these entities. In this context, we here provide a comprehensive perspective on lymphoma risk factors to support improved lymphoma risk assessment and testing. A dedicated clinical management could influence future advances in lymphoma therapies and might also prevent severe toxicity and secondary malignancies. However, to date, only few susceptibility genes for malignant lymphomas have been identified. Highly penetrant mutations in known genes cannot account for most of the excess in a polygenic and heterogenic disease such as cancer. High-throughput sequencing identifies pathogenic variants that may constitute most low-penetrance alleles. However, their detection requires many well-characterized cases and controls. In this review, we therefore also include a short discussion on a Swiss cohort where we prospectively collect and samples for genetic data from individuals with a family history of lymphoma. We are convinced that such an approach is more informative and feasible than a population-based project with unselected cases and aim to better inform both genetic counsellors and oncologists. CONCLUSION: Inherited genetic factors contribute to lymphoma risk in a subset of patients. Improved identification of susceptibility variants, particularly through family-based studies, may enhance risk assessment and inform personalized clinical management.

Humans↗
PubMed2026

Genetically Guided Pharmacotherapy for Structural Neurovascular Lesions.

Structural neurovascular lesions (SNVLs)-arteriovenous malformations, cavernous malformations, and vein of Galen aneurysmal malformations, among others-have historically been treated using neurosurgical, radiotherapeutic, and endovascular approaches. However, lesion size, location, and presence of high-risk angioarchitectural features preclude many patients from receiving these treatments. Advances in human genetics and cerebrovascular biology have redefined SNVLs as dynamic, genetically driven lesions where sporadic cases are caused by somatic variants. Intriguingly, many SNVL-causing variants are also oncogenic and active drug targets. These data provide the rationale for a genetically driven taxonomy to guide targeted therapeutic selection. In this commentary, we synthesize efforts toward pharmacologic treatments of SNVLs and highlight how variant-specific or pathway-modulating therapies may be investigated, incorporating key considerations in molecular diagnosis, cerebrovascular biology, and molecular and phenotypic outcome measures, in forthcoming clinical trials. Together, these advances support the investigation of pharmacologic treatment strategies in carefully selected patients with SNVLs.

Journal Article↗
PubMed1988

Analysis of rheumatoid factor autoantibodies in patients with essential mixed cryoglobulinaemia and rheumatoid arthritis.

Approximately 60% of human monoclonal rheumatoid factors from unrelated patients with cryoglobulinaemia share a common idiotype (Wa). Analysis of Ig V regions revealed that these rheumatoid factors utilize highly homologous light chains from the VKIIIb sub-subgroup. More recent studies showed a similar restriction in the use of VHI and JH4 and a restriction in the size of the D segment. In the present experiments the structural features of RFs from patients with cryoglobulinaemia were studied using a panel of murine monoclonal antibodies. The pattern of expression of these idiotypes were investigated among diverse patients with rheumatoid arthritis and normal individuals. Though in general higher levels of crossreactive idiotypes from the Wa group are detected in rheumatoid arthritis patients compared to normals, their levels in polyclonal rheumatoid factors is low. Therefore the major proportion of polyclonal rheumatoid factors in rheumatoid arthritis represent the products of somatic variants of monoclonal rheumatoid factor V genes or a larger gene pool.

Antibody Specificity↗
PubMed2026

Preemptive hematopoietic stem cell transplantation in RUNX1 familial platelet disorder: a shared decision-making framework.

RUNX1 familial platelet disorder (RUNX1-FPD) is associated with a 35-50% lifetime risk of hematologic malignancy (HM). Like all germline HM predisposition syndromes, RUNX1-FPD can only be cured with allogeneic hematopoietic stem cell transplantation (HSCT). Current genetic screening techniques allow for early detection of germline predisposition and, consequently, the opportunity for HSCT before overt development of HM (i.e., preemptive HSCT). However, there is as yet no consensus on the use of preemptive HSCT for RUNX1-FPD. Described here is the case of an individual with RUNX1-FPD and a family history of HM who underwent preemptive HSCT. We introduce a shared decision-making framework designed to support individuals with RUNX1-FPD, their families, and their multidisciplinary clinical teams in evaluating whether and when to pursue preemptive HSCT versus continued surveillance. The framework reviews key medical factors that influence the decisions regarding timing of HSCT, including germline and somatic variants, clonal changes over time, familial history of HM, early morphologic or hematologic features, impacts on bleeding-related quality of life, and donor availability. The framework also summarizes the major risks and uncertainties potentially associated with preemptive HSCT while highlighting the associated ethical challenges. Together, the case and framework provide a structured, patient-centered approach for navigating the complex clinical decision of preemptive HSCT. Ongoing collaborative efforts to define cytogenetic and clonal changes preceding malignant transformation in RUNX1-FPD will refine the framework and bolster individualized treatment strategies aimed at preventing HM and improving the quality of life of individuals with RUNX1-FPD.

Humans↗
PubMed1990

[Andrologic problems in adolescence].

No precise distinction is usually made now between puberty and adolescence. Therefore, we describe the physiology and pathology of both phases with their characteristic clinical features, hormonal changes, and therapeutic consequences. In addition, we refer to the typical problems of this age group, the psychic and somatic variants of the norm; special regard is paid to puberal gynecomastia and obesity.

Adolescent↗
PubMed1990

Self-binding antibodies (autobodies) form specific complexes in solution.

In this report we have shown that members of the murine self-binding antibody family, S107, form soluble complexes and precipitate under conditions in which non-self-binding antibodies remain in solution. Two approaches were used to demonstrate the self-association of autobodies: size-exclusion column chromatography and polyethylene glycol (PEG)-mediated precipitation assay. The anti-phosphorylcholine antibody T15 and two somatic variants, U4, which binds DNA, and U10, which has no identified specificity, produced larger precipitates in 10% PEG than other non-self-binding antibodies. The selectivity of PEG-mediated precipitation of self-binding antibodies is demonstrated by reduction of precipitation with specific haptens known to inhibit self-binding in solid-phase assays. Phosphorylcholine and nucleotides reduced precipitation of T15 and U4, respectively, but not U10. To rule out Fc-Fc mediated self-association in solution, we have also demonstrated self-complexing of F(ab')2 fragments of T15 using PEG. The self-binding locus was further dissected using peptides derived from V regions. A 24-residue peptide derived from the second hypervariable region of the VH of S107 specifically enhanced precipitation of T15, U4, and U10, but not other antibodies. These results provide evidence of a dormant potential of self-binding antibodies to precipitate under conditions that reduce the solubility of proteins. The implication of this potential is discussed with respect to pathological complex formation.

Animals↗
PubMed1990

Development of B cell lineages during a primary anti-hapten immune response.

Cell lineage relationships were examined in large numbers of hybridomas derived from a single mouse at 7 days and from a single mouse at 12 days after a primary immunization. The properties of these developing lineages provide unique insight into their biologic selection and differentiation. The unique VDJ junctions, the characteristics of the somatic mutations, and the nonproductive H chain gene rearrangements observed at day 12 all indicate that the hybridomas were derived from a limited number of progenitor B cells. Clonally related hybridomas were also observed at day 7. The activation of these lineages occurred very early, because somatic variants were strongly selected for within a few days after the primary immunization.

Animals↗
PubMed1989

Characterization of allelic V kappa-1 region genes in inbred strains of mice.

Germ line genes encoding mouse Ig kappa-chains belonging to the V kappa-1 group have been isolated from BALB/c, NZB, and CE, three inbred strains of differing kappa haplotype. The V kappa-1A and V kappa-1C germ line genes isolated from BALB/c (Ig kappa c) were identical to those previously described. These are the two major V kappa-1 germ line genes in BALB/c and together account for 40 of the 53 expressed V kappa-1 sequences that have been reported to date. Allelic differences in a single germ line variable region gene (V kappa-1A) in different strains of mice explain the differences in L chain IEF patterns previously associated with the Ig kappa-Ef2 locus. The rearranged kappa-gene expressed in the BALB/c myeloma MOPC-460 has been isolated and found to represent a V kappa-1A somatic variant differing by three nucleotides from the germ line V kappa-1A gene. Germ line genes isolated from NZB (Ig kappa b) and CE (Ig kappa f) show greater than 95% identity with the BALB/c genes over the 1700 nucleotides compared. Comparison by region indicated the greatest conservation of sequence occurs in and around the leader exon followed by the V-region exon. The NZB gene encodes the amino acid sequence found in the myeloma PC-2205, previously designated V kappa-1B. The V kappa-1 gene isolated from CE is likely an allele of the BALB/c V kappa-1C gene as the two share greater than 96% identity over 1700 nucleotides. The CE gene has been designated V kappa-1Cf. Ancient remnants of LINE-1 repetitive elements were detected approximately 400 bp downstream of all of the V kappa-1 genes. These possess greater homology with repetitive elements found near other kappa genes than they do with the native L1Md sequence.

Alleles↗
PubMed1989

Regulation of idiotype expression. II. The phenotypic diversity of T15 idiotype-bearing antibody to phosphorylcholine in response to T-dependent and T-independent antigens.

The idiotypic (Id) diversity of the immune response to phosphorylcholine (PC) was studied by immunization of mice with thymus-dependent (PC-keyhole limpet haemocyanin; PC-KLH) and thymus-independent (S. pneumoniae R36a; Pn) forms of the antigen. Mice with the BALB/c genetic background (BALB/c, C.B20, and BALB.B) were used because their response to PC is dominated by immunoglobulins encoded in VH-1 and V kappa 22 genes, which uniformly express the T15 idiotype. The actual repertoire of the antibody was determined by idiotypic markers (Id) defined with monoclonal antibodies designated AB1-2, B36-82, MaId5-4, and B24-44. Previous studies from our laboratory have shown that these Id are present on T15 (VS107-1/V kappa 22) immunoglobulins only, but that they differentiate between somatic variants of the antibody molecules. We have measured the serum concentrations of these four Id after primary (1 degree), secondary (2 degree), and tertiary (3 degree) immunization; all of the Id activity was associated with the PC-binding antibody, as shown by specific immunoadsorbents. However, the levels of the Id-bearing (Id+) antibody did not correlate with each other. After immunization with PC-KLH, the AB1-2+ antibody declined precipitously, whereas the levels of B24-44 and B36-82 remained steady. A similar pattern of Id heterogeneity was seen at the level of direct antibody-plaque-forming cells from the spleen, suggesting that the idiotopic (clonal) diversification occurred already during the early IgM response. A significant portion of anti-PC antibody after the 3 degrees PC-KLH immunization was negative for all four Id, implying that the late response to the antigen involved distinct, T15-negative clones.

Animals↗
PubMed1986

Expression of three cross-reactive idiotypes on rheumatoid factor autoantibodies from patients with autoimmune diseases and seropositive adults.

Approximately one-half of human monoclonal IgM anti-IgG autoantibodies (rheumatoid factors (RF] from unrelated individuals with cryoglobulinemia coordinately express three cross-reactive idiotypic antigens (CRI). The CRI are detected with: 1) monoclonal antibody 17.109, which recognizes a conformation-dependent CRI on K-light chains; and 2) two rabbit anti-peptide antibodies that react with primary sequence-dependent CRI (PSL2 and PSL3) corresponding to the conserved second and third K-chain complementarity-determining regions, respectively. In the present experiments, the structural features of polyclonal RF autoantibodies from diverse patients with rheumatoid arthritis and from those with primary Sjögren's syndrome, and from seropositive elderly subjects without overt autoimmune diseases, were investigated with these three defined anti-CRI reagents. The pattern of expression of the CRI differed among patient groups. Only the RF autoantibodies from Sjögren's syndrome patients frequently displayed all three CRI. However, the RF from nearly every subject tested, including patients with rheumatoid arthritis, were enriched in the primary sequence-dependent PSL2-CRI as compared to RF-depleted Ig from the same subjects. Amino acid sequence analysis of monoclonal IgM-RF indicates that PSL2-CRI-positive light chains probably represent the products of a single Vk gene. Therefore, a proportion of the polyclonal RF from different autoimmune states may represent somatic variants of this germ-line RF Vk gene which retain the PSL2 sequence as a common element.

Adult↗
PubMed1986

Genetic basis for altered idiotype expression in the hyperimmune response to (4-hydroxy-3-nitrophenyl)acetyl hapten.

To assess the significance of somatic point mutation in the hyperimmune response to the hapten NP, an in vivo enrichment procedure was followed. Mice that expressed high titers of B1-8 idiotopic determinants were selected as donors for serial transfer of small numbers of immune spleen cells into syngeneic irradiated recipient mice. Cells expressing B1-8 idiotopic determinants were chosen for enrichment because B1-8 cross-reactive determinants constitute a significant portion of the primary response. Furthermore, B1-8 is a monoclonal antibody derived from a primary response to NP, and its heavy and light chains are unmutated products of the germ-line genes VH186.2 and VL lambda 1, respectively. The germ-line sequence is thus available for comparison with the somatic mutants that arise during enrichment and hyperimmunization. The data show that serial transfer of spleen cells from mice with a high titer of idiotypic determinants results in a dramatic decrease in the titers of antibodies that bind antigen. Three lines of evidence indicate that progeny cells from the initial lambda-positive, idiotype-bearing, antigen-binding cells are successfully transferred and expanded during successive adoptive transfers. First, the proportion of lambda-bearing antibodies relative to NP-specific lambda-bearing antibodies increases with transfer, which is consistent with mutation away from antigen binding. Second, analysis of serum antibodies and hybridoma proteins derived from transfer-recipient mice confirm the presence of idiotype-positive antibodies that do not bind antigen. Third, RNA dot blot analysis of hybridomas constructed from a recipient mouse in the fourth transfer indicates a high frequency of expression of the VH gene predominantly used in the NP response. Many of the antibodies expressed by these hybridomas not only do not bind antigen, but have also lost the determinants recognized by the anti-idiotypic reagents. Most of these VH-positive hybridomas express lambda L chain. The most likely interpretation of the data is that somatic mutation is occurring during the hyperimmune response. Because we selected donor mice that expressed a high titer of idiotype-positive, antigen-specific antibody and immunized the recipient mice, we expected to observe a selective expansion of somatic variants that bound antigen. This was not the case. The observed loss of antigen binding suggests that the majority of mutations arising result in antibodies with lower affinity for the immunizing antigen.

Animals↗
PubMed1985

Cross-reactive idiotype family observed in the phthalate-specific B cell repertoire of adult BALB/c mice: diversity of IgM compared with IgG monoclonal anti-phthalate antibodies.

A highly conserved clonotype has been identified within the repertoire of B cells specific for the negatively charged hapten phthalate. The prototype of this phthalate-specific clonotype is a primary-response hybridoma (2E9) that produces a mu,kappa anti-phthalate antibody. The 2E9 monoclonal antibody was found to share idiotypic determinants with several other independently-derived mu,kappa and gamma 1,kappa anti-phthalate monoclonal antibodies and with a significant proportion of conventional anti-phthalate antibodies derived from all of the BALB/c mice immunized with phthalate-keyhole limpet hemocyanin. Competitive RIA analysis of the 2E9 idiotypic relatedness between primary and secondary response antibodies was consistent with the hypothesis that the primary response mu,kappa antibodies represent a conserved germ-line product, whereas the secondary response to gamma 1,kappa antibodies reflect somatic variants of the 2E9 clonotype. Further analysis with a site-specific anti-idiotype reagent suggests that the idiotypic differences between mu,kappa and gamma 1,kappa monoclonal antibodies occur at positions outside of the combining site. Fine specificity analysis of the monoclonal antibodies expressing the 2E9 cross-reactive idiotype (CRI) also supports this hypothesis. Seven to 35% of the anti-phthalate antibodies after a single immunization with phthalate-KLH and 1 to 10% of the antibodies after a second immunization express the 2E9 CRI. The 2E9 CRI was also found in several other strains of mice, and its expression was associated exclusively with anti-phthalate antibodies.

Aging↗
PubMed1984

Immunologic memory to phosphocholine. V. Hybridomas representative of group II antibodies utilize V kappa 1-3 gene(s).

The anti-phosphocholine (PC) memory response of BALB/c mice to PC-KLH contains two groups of antibodies distinguished by fine specificity and by expression of the T15 idiotype that dominates Group I but not Group II anti-PC antibodies. The contribution of V kappa genes to this diversity was investigated by the analysis of L chains from PC-binding hybridoma proteins (PCBHP) representative of Group I and Group II. N-terminal amino acid sequence analysis was performed on the L chains of three independently derived Group II PCBHP up to residue 23 (PCG1-1) or 21 (aPC-111-1 and aPC-12-3). These three sequences differed from each other by only one or two residues, but differed by approximately 50% from the L chains of the Group I-like PC-binding myeloma proteins (PCBMP); the Group II sequences are closely related to V kappa 1-3. Isoelectric focusing analysis was also performed on the L chain of PCG1-1, as well as on L chains from PCBHP typical of Group I antibodies, and from an atypical PCBHP differing from Groups I and II in fine specificity. A Group I PCBHP and the atypical PCBHP expressed L chains related to V kappa 8 and V kappa 24, respectively. The L chains of another Group I PCBHP and of the Group II protein, PCG1-1, appeared different from those found in the PCBMP and from each other. The results indicate a more diverse expression of L chains in the memory anti-PC response than is represented by the PCBMP; both V kappa 8- and V kappa 24-derived L chains (and, presumably, somatic variants), as well as products of additional V kappa genes (V kappa 1-3), appear to be present in the anti-PC memory pool.

Amino Acid Sequence↗
PubMedDate not supplied

[Histone H1 from the herring Clupea harengus pallasi testis structurally resembling histone H5].

Erythrocyte- and testis-specific fractions of the lysine-rich histone of herring Clupea harengus pallasi were studied. Electrophoretically purified fractions were cleaved at residues of tyrosine and phenylalanine. The fragments thus obtained and intact proteins were investigated by the method of incomplete succinylation which permitted one to determine the number of lysine residues, the total number of arginine and histidine residues and the molecular length of polypeptides. It has been found that the testis-specific fraction has in its C-terminal half of the molecule 15 arginine residues and a high proportion of basic amino acid residues (0,49) and thereby resembles the histone H5 of birds and fishes. The N-terminal half of this fraction however is close to the somatic variants of lysine-rich histones by the number of arginine residues and by the proportion of basic amino acid residues. To the author's knowledge, the testis-specific fraction of the lysine-rich histone in fishes are described for the first time.

Amino Acid Sequence↗
PubMed1993

Temporal and tissue-specific interactions involving novel transcription factors and the proximal promoter of the mouse Pdha-2 gene.

We have determined by deletion analysis that the most proximal region of the Pdha-2 promoter between nucleotide position -187 to +22 harbors a transcriptionally active core. This "core" promoter directs high levels of CAT (chloramphenicol acetyltransferase) reporter gene transcription in HeLa cells. DNase I footprinting of the proximal promoter revealed four regions of protection. One of these contains the consensus sequence for the Sp1 binding site and another the ATF/CREB binding site. The cis-sequences of the remaining two protected regions (designated MEP-2 and MEP-3; Mouse E1 alpha Promoter site) show no apparent consensus homology with cis-elements of other known transcription factors. Results of electrophoretic mobility shift assays confirm that the ATF/CREB and MEP binding sites interact in a characteristic and specific manner with factors present in nuclei of both testis and somatic tissue. The factor which recognizes the MEP-3 motif appears to be ubiquitous, whereas the MEP-2-protein complexes were tissue-specific. Interestingly, formation of a complex involving MEP-2 and a putative testis-specific binding factor (tau-MEP-2BF) is first observed in the testis of 2-week-old mice, this correlates with the expression of Pdha-2. In contrast, the formation of complexes between the MEP-2 binding site and a somatic variant of MEP-2BF (sigma-MEP-2BF) decreases in the testis as spermatogenesis proceeds. Our results suggest that 1) the MEP-2 binding factors are temporally regulated during spermatogenesis, and 2) interactions involving these factors with the MEP-2 cis-element may be important for modulating Pdha-2 expression.

Aging↗
PubMed1998

H1 histone as a trans-acting factor involved in protecting genomic DNA from full methylation.

This review aims to explain why H1 histone can be considered as a protein involved in protecting genomic DNA from full methylation. Some of our results indicated that, to explain the multiple roles in which H1 histone seems to be involved, it is important to consider that it is not a unique protein but a family of genetic somatic variants and that every one of them can be dynamically modified by different post-synthetic enzymatic modifications. Our data show that H1 histone plays an inhibitory effect on DNA methylation through its H1e variant and that poly(ADP-ribosyl)ation is a post-synthetic modification involved in this regulatory role. The idea that the poly(ADP-ribosyl)ated isoform of H1e could be present in decondensed chromatin structure, where the housekeeping genes are located, will be discussed.

DNA Methylation↗
PubMed1983

Immunogenic variants obtained by mutagenesis of mouse mastocytoma P815. VII. Dominant expression of variant antigens in somatic cell hybrids.

After mutagenesis of mouse mastocytoma P815, it is possible to obtain at high frequency stable tumor cell variants (tum-) that are rejected by syngeneic DBA/2 mice. Most of the variants express one or more new individual antigens specific for each variant, that are detectable in vitro by cytolytic T cells (CTL). Somatic hybrids were prepared either between tum- variants and the original P815 clone, or between different variants. Antigen expression of the hybrids was assessed by using long-term CTL clones that recognize specifically the new antigen present on the variants. Expression of tum- variant antigens behaved as a dominant trait in the hybrids. By submitting the somatic hybrids to selection with CTL clones, it was possible to obtain antigen-loss hybrid variants. The analyses of these antigen-loss variants showed that two variant-specific antigenic determinants associated with one of the variant fusion partners could be lost independently. Like the parental tum- variants, both the (tum+ X tum-) and (tum- X tum-) hybrids failed to form tumors in normal mice but formed tumors in irradiated mice.

Animals↗