👤 Ryan P Hobbs

Systemic light chain amyloidosis (AL) arises from monoclonal immunoglobulin light chains, but determinants of progression from precursor states remain poorly defined. In a cross-sectional cohort comprising 1950 systemic AL patients diagnosed 2010-2024, 258 (13.2%) patients with a previously diagnosed plasma cell disorder (PCD) were compared to patients with no prior PCD diagnosis. Patients with monoclonal gammopathy of undetermined signficance (MGUS) and smoldering multiple myeloma (SMM) in the former group had lower difference between involved and uninvolved FLCs (dFLC), higher M-protein, and lower rates of t(11;14) at AL diagnosis. Patients developing AL from SMM had a shorter time to AL (median 34.2 versus 61.3 months) and higher dFLC (median 28.9 versus 11.0 mg/dl) compared to those from MGUS. Patients developing AL after known multiple myeloma (MM) or lymphoplasmacytic lymphoma (LPL) commonly lacked deep hematologic response before AL (≤ very good partial response in 78% of MM, 100% of LPL patients). We additionally studied longitudinally followed cohorts of 3,966 MGUS and 426 (SMM) patients with longitudinal FLC measurements and matched follow-up, in which 1.8% of MGUS and 7.2% of SMM patients developed AL. Those patients who developed AL showed markedly higher dFLC at MGUS/SMM diagnosis and more frequent λ restriction and rates of t(11;14). Higher dFLC was associated with progressively earlier AL development; a 10% cumulative risk occurred at 20 months for patients with a dFLC >80 mg/dL but was not reached if dFLC <10 mg/dL at an estimated median follow-up of 86 months. In multivariable analysis, dFLC >6.4 mg/dL (HR 11.3) and λ isotype (HR 3.6) independently predicted AL, whereas heavy chain secretion was associated with lower risk (HR 0.2 for IgG). These findings indicate that AL risk is primarily driven by cumulative light chain exposure, refining our knowledge of AL pathophysiology and providing guidance for follow-up of patients with elevated dFLC. Show less

"Nonclassical" myeloproliferative neoplasms (MPNs) and myelodysplastic/myeloproliferative neoplasms (MDS/MPNs) represent a heterogeneous group of malignancies characterized by a wide range of clinical manifestations. Unlike classical MPNs, there is no standardized management approach for these conditions, particularly concerning the indications for and management of allogeneic hematopoietic cell transplantation. To address this gap, the European Society for Blood and Marrow Transplantation (EBMT) Practice Harmonization and Guidelines (PH&G) Committee and the Chronic Malignancies Working Party (CMWP) have collaborated to develop shared guidelines aimed at optimizing the selection and management of patients with these rare forms of neoplasms. A comprehensive review of the literature from the publication of the revised fourth edition of the (2016) World Health Organization classification onward was conducted. A multidisciplinary group of experts in the field convened to produce this document, which was developed through multiple rounds of draft circulation. Key recommendations include the early identification of potential transplant candidates, particularly in cases of chronic neutrophilic leukemia, chronic eosinophilic leukemia (CEL)/CEL, not otherwise specified (CEL-NOS), myeloid/lymphoid neoplasm with eosinophilia and tyrosine kinase gene fusions with FGFR1, JAK2, ABL1, and FLT3 rearrangements, MDS/MPN with neutrophilia/atypical chronic myeloid leukemia, and MDS/MPN, NOS. For patients with MPN, NOS/MPN unclassifiable, standard recommendations for myelofibrosis should be applied. Similarly, in MDS/MPN with thrombocytosis, transplantation is recommended on the basis of established MDS guidelines. Given the current lack of robust evidence, this document will serve as a valuable resource to guide future research activities, providing a framework for addressing critical unanswered questions and advancing the field. Show less

Obesity is a major public health crisis associated with high mortality rates. Previous genome-wide association studies (GWAS) investigating body mass index (BMI) have largely relied on imputed data from European individuals. This study leveraged whole-genome sequencing (WGS) data from 88,873 participants from the Trans-Omics for Precision Medicine (TOPMed) Program, of which 51% were of non-European population groups. We discovered 18 BMI-associated signals (P < 5 × 10 Show less

Smoothened inhibitors, such as vismodegib, exhibit remarkable success in treating patients with locally advanced basal cell carcinoma (LaBCC). Yet, vismodegib efficacy is hindered by notable side effects, which often lead to treatment discontinuation and subsequent relapse in patients with LaBCC. Prolonged remission was previously reported in patients with LaBCCs who underwent surgical debulking before starting vismodegib. In this study, we enrolled 4 patients with LaBCC who underwent debulking followed by vismodegib therapy to assess their clinical outcomes and analyze the cutaneous molecular changes occurring as a result of surgical intervention. After LaBCC debulking, patients underwent a punch biopsy of residual basal cell carcinoma tissue 1 week later. RT-qPCR analysis of 24 Notch and Wnt signaling-associated genes revealed elevated Show less

Obesity is a major public health crisis associated with high mortality rates. Previous genome-wide association studies (GWAS) investigating body mass index (BMI) have largely relied on imputed data from European individuals. This study leveraged whole-genome sequencing (WGS) data from 88,873 participants from the Trans-Omics for Precision Medicine (TOPMed) Program, of which 51% were of non-European population groups. We discovered 18 BMI-associated signals ( Show less

Two new studies report that triglyceride (TG)-lowering mutations in APOC3 reduce coronary heart disease (CHD) (Crosby et al., 2014; Jørgensen et al., 2014). Here, we explore limitations of using Mendelian randomization to evaluate CHD risk, including potential confounding by the widespread use of statin therapy. Show less

Angiopoietin-like proteins (ANGPTLs) play major roles in the trafficking and metabolism of lipids. Inactivation of ANGPTL3, a gene located in an intron of DOCK7, results in very low levels of LDL-cholesterol (C), HDL-C and triglyceride (TAG). We identified another ANGPTL family member, ANGPTL8, which is located in the corresponding intron of DOCK6. A variant in this family member (rs2278426, R59W) was associated with lower plasma LDL-C and HDL-C levels in three populations. ANGPTL8 is expressed in liver and adipose tissue, and circulates in plasma of humans. Expression of ANGPTL8 was reduced by fasting and increased by refeeding in both mice and humans. To examine the functional relationship between the two ANGPTL family members, we expressed ANGPTL3 at physiological levels alone or together with ANGPTL8 in livers of mice. Plasma TAG level did not change in mice expressing ANGPTL3 alone, whereas coexpression with ANGPTL8 resulted in hypertriglyceridemia, despite a reduction in circulating ANGPTL3. ANGPTL8 coimmunoprecipitated with the N-terminal domain of ANGPTL3 in plasma of these mice. In cultured hepatocytes, ANGPTL8 expression increased the appearance of N-terminal ANGPTL3 in the medium, suggesting ANGPTL8 may activate ANGPTL3. Consistent with this scenario, expression of ANGPTL8 in Angptl3(-/-) mice failed to promote hypertriglyceridemia. Thus, ANGPTL8, a paralog of ANGPTL3 that arose through duplication of an ancestral DOCK gene, regulates postprandial TAG and fatty acid metabolism by controlling activation of its progenitor, and perhaps other ANGPTLs. Inhibition of ANGPTL8 provides a new therapeutic strategy for reducing plasma lipoprotein levels. Show less

Nonalcoholic fatty liver disease (NAFLD) is an escalating health problem that is frequently associated with obesity and insulin resistance. The mechanistic relationship between NAFLD, obesity, and insulin resistance is not well understood. A nonsynonymous variant in patatin-like phospholipase domain containing 3 (rs738409, I148M) has been reproducibly associated with increased hepatic triglyceride content (HTGC) but has not been associated with either the body mass index (BMI) or indices of insulin resistance. Conversely, two sequence variants in apolipoprotein C3 (APOC3) that have been linked to hypertriglyceridemia (rs2854117 C > T and rs2854116 T > C) have recently been reported to be associated with both hepatic fat content and insulin resistance. Here we genotyped two APOC3 variants in 1228 African Americans, 843 European Americans and 426 Hispanics from a multiethnic population based study, the Dallas Heart Study and test for association with HTGC and homeostatic model of insulin resistance (HOMA-IR). We also examined the relationship between these two variants and HOMA-IR in the Atherosclerosis Risk in Communities (ARIC) study. No significant difference in hepatic fat content was found between carriers and noncarriers in the Dallas Heart Study. Neither APOC3 variant was associated with HOMA-IR in the Dallas Heart Study; this lack of association was confirmed in the ARIC study, even after the analysis was restricted to lean (BMI < 25 kg/m(2) ) individuals (n = 4399). Our data do not support a causal relationship between these two variants in APOC3 and either HTGC or insulin resistance in middle-aged men and women. Show less

Activation of liver X receptors (LXRs) inhibits the progression of atherosclerosis and promotes regression of existing lesions. In addition, LXRα levels are high in regressive plaques. Macrophage arginase 1 (Arg1) expression is inversely correlated with atherosclerosis progression and is markedly decreased in foam cells within the lesion. To investigate LXRα regulation of Arg1 expression in cultured macrophages and atherosclerotic regressive lesions. We found that Arg1 expression is enhanced in CD68+ cells from regressive versus progressive lesions in a murine aortic arch transplant model. In cultured macrophages, ligand-activated LXRα markedly enhances basal and interleukin-4-induced Arg1 mRNA and protein expression as well as promoter activity. This LXRα-enhanced Arg1 expression correlates with a reduction in nitric oxide levels. Moreover, Arg1 expression within regressive atherosclerotic plaques is LXRα-dependent, as enhanced expression of Arg1 in regressive lesions is impaired in LXRα-deficient CD68+ cells. LXRα does not bind to the Arg1 promoter but instead promotes the interaction between PU.1 and interferon regulatory factor (IRF)8 transcription factors and induces their binding of a novel composite element. Accordingly, knockdown of either IRF8 or PU.1 strongly impairs LXRα regulation of Arg1 expression in macrophage cells. Finally, we demonstrate that LXRα binds the IRF8 locus and its activation increases IRF8 mRNA and protein levels in these cells. This work implicates Arg1 in atherosclerosis regression and identifies LXRα as a novel regulator of Arg1 and IRF8 in macrophages. Furthermore, it provides a unique molecular mechanism by which LXRα regulates macrophage target gene expression through PU.1 and IRF8. Show less