EACTS Expert Consensus Document on protected cardiac surgery: pre-emptive use of temporary mechanical circulatory support in adult cardiac surgery patients at high risk for perioperative low cardiac output syndrome
Abstract Perioperative low cardiac output syndrome (LCOS) remains a significant complication in adult cardiac surgery, contributing to substantial morbidity, prolonged intensive care, and increased mortality. Its incidence is expected to rise further due to the evolving complexity of referred surgical patients, often characterised by advanced age, multiple comorbidities, challenging anatomy, and impaired haemodynamics. Despite advances in pharmacological and perioperative care, outcomes for high-risk patients have not shown significant improvement, prompting interest in temporary mechanical circulatory support (tMCS) as a proactive strategy. This Expert Consensus Document from the European Association for Cardio-Thoracic Surgery (EACTS) presents the first dedicated guidance on the pre-emptive use of tMCS in high-risk adult cardiac surgical patients. Developed by a multidisciplinary task force, it emphasises structured risk stratification, early initiation, and individualised device management informed by interdisciplinary Heart Team discussions. The document proposes clinical pathways for patient selection, defines criteria for tMCS initiation, and provides practical algorithms for various scenarios, including advanced heart failure, cardiogenic shock, and post-cardiotomy LCOS. It reviews the current evidence on available tMCS devices, such as intra-aortic balloon pumps, microaxial flow pumps, veno-arterial extracorporeal life support and hybrid strategies, and addresses perioperative care, intensive care unit protocols, ethical considerations, as well as informed consent and support withdrawal. Despite promising results, substantial knowledge gaps remain, including long-term outcome data, device selection criteria, and cost-effectiveness analyses. This consensus aims to support clinical decision-making, standardise practice, and stimulate research to improve outcomes in a growing population of high-risk surgical patients.
Commentary on Aberrant Plasma Cells in the Absence of M-Protein: Ancillary Testing beyond Protein Electrophoresis
With the first series of PRRX1 -rearranged tumors published in 2019, the spectrum of these so-called fibroblastic tumors has been expanded. Since then, several smaller case series have been published; however, our understanding of them continues to be quite limited given their rarity. We herein studied 18 additional cases, the largest series to date. Eighteen tumors present in 9 male, 8 female, and 1 nonbinary patient with a median age of 35 years (range: 11 to 70 y) and involved the neck (5), the chest region (4), thigh (3), back (1), shoulder (1), forehead (1), lower leg (1), axilla (1), and the parapharyngeal region (1). Clinical follow-up (9/18 tumors; 50%; median: 10 mo; range: 4 to 40 mo) showed consistent indolent behavior without local recurrences or distant metastases. On morphology, these tumors were characterized by well-circumscription and distinctive peripheral crescent-shaped vessels. They were composed of uniform spindle and round cells growing in short fascicles within often densely hyalinized collagen lacking significant mitotic activity, necrosis, or cytologic atypia. Immunohistochemically, about half of the tested tumors expressed focal to rarely diffuse S100 with occasional co-expression of SOX10. Interestingly, almost half of the tested cases also showed complete loss of RB expression. All but 1 tumor harbored a PRRX1::NCOA1 fusion, while 1 case harbored a novel PRRX1::EP300 fusion. We herein provide additional data on these exceptionally uncommon tumors, expand their molecular spectrum, and compare them to their close morphologic mimics to aid in accurate diagnosis and avoid confusion with potentially more aggressive neoplasms.
Eliminating REMS for CAR T-Cell Therapies: An Opportunity to Improve Access
Autologous Chimeric antigen receptor (CAR) T-cell therapies have demonstrated substantial efficacy in patients with relapsed or refractory hematologic malignancies; however, their implementation has been constrained by regulatory barriers. Risk Evaluation and Mitigation Strategies (REMS), mandated by the U.S. Food and Drug Administration (FDA), were initially implemented to mitigate risks associated with cytokine release syndrome (CRS), immune effector cell-associated neurotoxicity syndrome (ICANS), and other treatment-related toxicities. On 27 June 2025, the FDA removed REMS requirements for all approved B-cell maturation antigen (BCMA) and CD19-directed autologous CAR T-cell therapies, citing that current product labeling sufficiently communicates safety information. Key regulatory changes include the elimination of site certification and tocilizumab stocking requirements, a reduction in the recommended post-infusion proximity period from four weeks to two weeks, increased flexibility regarding monitoring locations, and a shortened driving restriction from eight weeks to two weeks. This review examines the rationale for the REMS requirements for CAR T-cell therapies, synthesizes contemporary safety data from clinical trials and real-world practice, and explores the implications of this regulatory shift for access to care, particularly in rural and underserved populations. The removal of REMS requirements may facilitate broader implementation of CAR T-cell therapies and alleviate logistical and institutional barriers, offering the potential to expand access while preserving patient safety.
Navigating the Spectrum of Pancreatic Surgery Complications: A Review
Background: Despite advances in surgical techniques and perioperative care, pancreatic resections such as pancreaticoduodenectomy (PD) and distal pancreatectomy (DP) remain high-risk procedures. Postoperative complications significantly impact morbidity, mortality, and patient quality of life. Methods: This narrative review summarizes recent literature on major complications following pancreatic surgery, including postoperative pancreatic fistula (POPF), delayed gastric emptying (DGE), and post-pancreatectomy hemorrhage (PPH), with an emphasis on incidence, risk factors, outcomes, and current preventive strategies. Results: POPF is a leading complication, occurring in 5–22% of cases and often linked with sepsis and hemorrhage. Key risk factors include high BMI, soft pancreatic texture, and small duct size. Preventive measures like Pasireotide, modified anastomosis techniques, and neoadjuvant therapy show variable success. DGE affects up to 57% of PD patients and is associated with prolonged recovery; antecolic reconstruction and erythromycin may reduce incidence. PPH, though less frequent (3–13%), can be life-threatening, particularly when secondary to POPF. Endovascular approaches are now favored for late arterial bleeding. Other complications include wound infections, abscesses, bile leaks, and pulmonary issues, all contributing to extended hospital stays and diminished quality of life. Conclusions: Pancreatic surgery continues to carry significant risks, with POPF, DGE, and PPH being the most impactful complications. While multiple interventions have shown promise, standardized protocols and predictive tools are still needed. Surgery should be performed in high-volume centers with experienced multidisciplinary teams to optimize outcomes.
B-265 Significance of CSF Aß42/40 and p-Tau181/Aß42 Ratio Discrepancy in the Diagnosis of Alzheimer’s Disease
Abstract Background Alzheimer’s disease (AD) cerebrospinal fluid (CSF) biomarkers, including the Aß42/40 and p-tau181/Aß42 ratios, are used in clinical practice to detect the presence of amyloid pathology for the diagnosis of AD. However, in some instances, discrepancies between Aß42/40 and p-tau181/Aß42 are observed. Such discrepancies may introduce uncertainties in the clinical management of patients presenting with cognitive decline. Identifying the underlying causes of these discrepancies and determining which biomarker abnormalities better predict disease progression is crucial to enhancing confidence in the use of these CSF biomarkers for the diagnosis of AD. This study aims to investigate the discordance between the Aß42/40 and p-tau181/Aß42 ratios, evaluate the frequency of these discrepancies, and identify potential causes. Methods Data from 958 individuals who had both CSF Aß42/40 and p-tau181/Aß42 tested at Mayo Clinic Laboratories between 2022 and 2024 and where the tests were ordered in CSF collected during the same lumbar puncture procedure were included. Cases with an inadequate sample collection, which could cause a false decrease in Aß42 concentrations, were excluded from the analysis. Aß42/40 was measured using the Fujirebio LUMIPULSE assays and reported as negative, likely positive, or positive. For this analysis, likely positive and positive results were combined and considered as positive (<0.072). P-tau181/Aß42 was measured using the Roche Elecsys assays and above 0.028 was considered positive. Statistical analyses were conducted using R Studio. Results Aß42/40 was positive in 69.1% of cases (n=661), while p-tau181/Aß42 was positive in 62.1% (n=594). There were 8.0% discordant cases (n=77). Most frequently, the discordant cases had an abnormal Aß42/40 with a normal p-tau181/Aß42 (Aß42/40+/p-tau181/Aß42-; n=72, 94%). Compared to the concordant Aß42/40+/p-tau181/Aß42+ group, the discordant Aß42/40+/p-tau181/Aß42- group showed significantly higher Aß42 concentrations (p <0.001, median [pg/mL]: 878.5 vs 587.0, respectively); whereas p-tau181 concentrations were significantly lower (p <0.001, median [pg/mL]: 19.3 vs 32.1, respectively). Among the Aß42/40+/p-tau181/Aß42- group, 30 cases exhibited abnormally low Aß42 and normal p-tau181, possibly reflecting early-stage AD. There were 41 cases with a normal Aß42 concentration despite an abnormal Aß42/40, possibly reflecting an overall higher production of Aß peptides resulting in an increased Aß40 peptide (median [pg/mL]: 12627 compared to 9487 in the low Aß42 and normal p-tau181 cases (n=30); p <0.001). Of these 41, 19 showed normal Aß42 but elevated p-tau181 concentrations where the use of Aß42/40 compensated for the overall higher production of Aß peptides, resulting in an abnormal ratio. In contrast, the p-tau181/Aß42 ratio was not able to normalize for these differences, leading to a normal ratio. Conclusion While overall concordance was 92.0%, our findings suggest that discrepancies between CSF Aß42/40 and p-Tau181/Aß42 are more often due to the presence of an abnormal Aß42/40 and a normal p-Tau181/Aß42. Two potential explanations for these discrepancies are early-stage AD or higher production of Aß peptides in some individuals. In the latter, differences in amyloid production would be normalized by ratios of the same biomarker (i.e. Aß42/40) but not by ratios of different biomarkers (i.e. p-Tau181/Aß42).
B-223 DMD Duplications Identified by Carrier Screening Should NOT Automatically Be Classified as [Likely] Pathogenic: Data from Long-Read Sequencing of 15 Cases
Abstract Background Pathogenic variants in the DMD gene are associated with Duchenne and Becker muscular dystrophy (DMD/BMD). Professional medical societies currently recommend DMD carrier screening for all patients who are pregnant or considering pregnancy. Such testing may identify intragenic duplications of DMD (i.e., involving one or more exons but fully contained with the gene) in patients without a personal or family history of DMD/BMD. These incidentally detected DMD intragenic duplications, however, pose significant challenges for variant interpretation. Pathogenicity of an intragenic duplication depends on its structural configuration. Tandem duplications may cause reading frame disruption and gene loss-of-function; conversely, non-tandem duplications may not disrupt gene function. Current carrier screening assays cannot determine the structural configuration of an intragenic duplication. The current guidelines (e.g., the ClinGen PVS1 decision tree) presume intragenic duplications are in tandem unless proven otherwise. If this presumption of tandem configuration is inaccurate, it may lead to overestimation of variant pathogenicity, potentially resulting in unnecessary invasive procedures (e.g., amniocentesis for prenatal diagnosis) and/or having other negative impacts with regards to prenatal decision-making. This study aims to evaluate the validity of this presumption for incidentally detected DMD intragenic duplications. Methods We performed high-coverage whole-genome long-read sequencing on the PromethION instrument (Oxford Nanopore Technologies) for 15 cases with previously identified DMD intragenic duplications. Among these cases, four had personal or family history of DMD/BMD, while 11 had no known history (i.e., incidentally detected). The structural configurations of the duplications were determined by an in-house bioinformatics tool and manual inspection of the alignment files. Results In all 4 cases with a known personal or family history of DMD/BMD, the DMD intragenic duplications were confirmed to be in tandem, aligning with expectations of their pathogenicity. Interestingly, among the 11 cases with incidentally detected DMD intragenic duplications, seven (64%) were found to involve interspersed duplications. In five of these seven interspersed duplication cases, the involved DMD exons were co-duplicated with distinct segments of the Xp arm located 0.5–30 Mb away, forming complex structural variants. In another case, the duplicated DMD exons have inserted into the Xq arm, about 90 Mb downstream of DMD. The final case involved the duplicated DMD exons inserted into a repetitive region most consistent with 9q12 (i.e., the 9qh region). Conclusions Our study reveals that while DMD intragenic duplications in patients with a personal or family history of DMD/BMD were consistently in tandem, a substantial 64% of incidentally detected DMD intragenic duplications were not in tandem. These findings have important implications for both clinicians and laboratorians. They challenge the presumption of tandem configuration for DMD intragenic duplications in individuals where the variants were identified incidentally, e.g., through carrier screening in those without a family history of DMD/BMD. In these cases, we recommend classifying the DMD intragenic duplications as variants of uncertain significance (VUS), unless there is evidence of tandem configuration.
B-183 Teclistamab: a bispecific monoclonal IgG lambda therapeutic is observable on serum immunofixation and mass-fix
Abstract Background Monoclonal antibody therapies (t-mabs) are known to interfere in serum immunofixation, as they show up as a discrete band. Until recently, most of the t-mabs were IgG kappa monoclonal immunoglobulins, and laboratories were familiar with the clue of a cathodal migrating IgG kappa in a patient sample, suggesting this could be daratumumab or another t-mab in the report. However, with the advent of novel antibody-based medications, identification via traditional laboratory methods has grown more complex. Teclistamab-cqyv is an IgG4 lambda T-cell engager bispecific antibody targeting B-cell maturation antigen (BCMA) and CD3 on T cells, used in relapsed and refractory multiple myeloma. The goal of this study was to determine if teclistamab could be detected on serum immunofixation and mass-fix. Methods Residual waste serum samples with no monoclonal protein via mass-fix (a MALDI-TOF based assay used in place of serum immunofixation) and variable polyclonal background were used to spike teclistamab (n=3). Briefly, one sample had total IgG < 500 mg/dL measured by nephelometry on a Siemens BNII (431 mg/dL, hypo gamma), a second sample had IgG within reference intervals (779 mg/dL, normal gamma) and the third sample had IgG > 1600 mg/dL (1950 mg/dL, polyclonal hypergamma). Each sample was divided into 3 aliquots and spiked with teclistamab (Tecvayli, Johnson &Johnson) obtained from the pharmacy, at final concentrations of 10, 20, and 40 mg/dL in the serum samples. The nine artificial samples were subjected to immunofixation electrophoresis (Sebia) and a new monoclonal protein study using mass-fix, a laboratory developed test. Results In the serum immunofixation experiments, a single discrete IgG lambda band was visible in the hypogamma and normal gamma samples (Table 1) when teclistamab was present at 20 mg/dL or 40 mg/dL. No bands were observed for the 10 mg/dL spike in hypos or normals. No teclistamab was detected at any concentration in the hypergamma sample. When mass-fix was performed, monoclonal protein spikes consistent with the expected mass of the two unique lambda light chains associated with teclistamab (22624Da and 22636Da) were identified in the hypo and normal gamma samples at the 3 concentrations tested: 10, 20, and 40 mg/dL. No mass-fix spikes were seen above the polyclonal spectra in the hypergamma samples. Conclusion The polyclonal background of immunoglobulins in a serum specimen plays a significant role in the identification of any monoclonal protein. Teclistamab is a new IgG lambda t-mab with potential to show up as an interference in both immunofixation and mass-fix, depending on the amount of polyclonal IgG present. Without positive identification, teclistamab presence could complicate interpretation of a patient’s response to treatment. This proof-of-concept study shows that mass-fix can detect smaller concentrations of teclistamab than immunofixation, therefore would be more prone to identifying this t-mab than labs employing the gel-based immunofixation method.
B-162 Optimizing Thyroid Function Testing: Reducing Unnecessary Orders and Enhancing Patient Care Through Evidence-Based Cascade Algorithms
Abstract Background Thyroid function testing is a common laboratory service that can be optimized by implementing evidence-based algorithms. The thyroid function cascade testing approach at Mayo Clinic Labs is utilized to effectively evaluate and monitor functional thyroid status. The cascade begins with thyroid-stimulating hormone (TSH) as a screening marker. When TSH levels are normal, no additional testing is necessary. When the TSH result is abnormal, appropriate follow-up free T4, total T3, and/or TPO testing will automatically be performed. Providers at our institution can order thyroid function testing with this cascade testing approach or as standalone individual orderable tests. Initial data analysis showed patterns of TSH ordered concurrently with free T4, total T3, and/or anti-TPO. Further analysis revealed that a high number of concurrently ordered tests would not have been necessary had the algorithmic approach been followed. This opportunity for improvement led to the thyroid function testing initiative to direct providers to order the cascade test rather than individual thyroid tests, thereby reducing concurrent and unnecessary testing to improve patient care. Methods The initiative involved creating a new Epic order panel directing providers to order the cascade rather than the individual orderable tests. This intervention is a soft stop that allows providers to proceed by ordering individual tests if desired. We evaluated the impact of the initiative on test utilization, cost savings, and quality indicators using pre- and post-intervention data from all Mayo Clinic sites over a 9-month period. We compared the monthly volumes of concurrent and unnecessary orders of Free T4, Total T3, and TPO before and after the intervention. Concurrent orders were defined as tests collected from the same patient on the same date and time as TSH tests. Unnecessary orders were defined as tests that were outside the reflex range according to the thyroid function ordering algorithm. Cost savings were calculated based on the 2024 CMS reimbursement rates for the associated test CPT® codes. We also monitored and addressed feedback and requests from providers and laboratory staff throughout the initiative. Results The intervention resulted in a 20% average monthly reduction in concurrent orders and an 18% average monthly reduction in unnecessary orders of free T4, total T3, and anti-TPO tests. Estimated savings based on 2024 CMS reimbursement rates are $5,000 monthly and nearly $60,000 annually. Thyroid testing quality was also improved by aligning with clinical guidelines, reducing over-testing, and minimizing the risk of misdiagnosis. Conclusion The thyroid function testing initiative was a successful laboratory stewardship project that reduced redundant testing, improved patient care, and reduced costs. The initiative demonstrated the feasibility and effectiveness of using evidence-based reflex algorithms to optimize laboratory testing. The lessons learned include assessing all tests related to the disease condition to mitigate potential unintended increases in test usage and accounting for patient groups that are not covered by the intended algorithm*s target population. Future directions include expanding the cascade approach to other areas of laboratory medicine, evaluating the long-term outcomes of the initiative, and engaging with providers to ensure the adoption of the initiative.
B-123 Clinical Implication of Light Chain Fragmentation in Patients with Monoclonal Gammopathies
Abstract Background The diagnosis of monoclonal gammopathies relies on the detection of monoclonal immunoglobulins (M-proteins) in serum or urine. Mass-Fix utilizes matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry (MS) to detect and quantify M-proteins. This method employs immunoaffinity enrichment using antibodies against heavy chains (HC) and light chains (LC), followed by MS analysis to determine M-protein isotypes. Mass-Fix has also revealed novel M-protein characteristics, including LC glycosylation and fragmentation, facilitated by measuring the mass of LC. LC glycosylation is as an independent risk factor for disease progression of monoclonal gammopathy of undetermined significance (MGUS), while light chain fragments have been postulated as the origin of amyloid light chain (AL) plaques. Since Mass-Fix enriches intact immunoglobulins before dissociating LCs, it potentially enhances fragment detection. However, the precise nature and clinical significance of these fragments remain to be fully elucidated. Methods Mass-Fix serum results from Mayo Clinic patients tested from September 10, 2018, to October 1, 2024, were reviewed for the presence of M-protein and LC fragments. The frequency and the isotype of fragment LC fragments was determined in the M-protein positive cohort (n=15410). Patients diagnosed with either MGUS (n=6996), AL amyloidosis (n=315), or both (n=32) who had positive M-protein results on Mass-Fix, either prior to or within one month after the diagnosis, were included for a retrospective clinical association study of LC fragments and disease. To validate that these fragments were not artifacts of MS analysis, PAGE gel analysis and Western blots were performed using clinical residual serum from 9 patients: 2 IgG/kappa and 3 IgG/lambda patients with detectable LC fragments and 2 IgG/kappa and 2 IgG/lambda patients without fragments. Samples were purified using antibodies against gamma heavy chains and reduced with TCEP prior to gel electrophoresis and Western blot. Results Of the 15410 patients with monoclonal proteins detected by Mass-Fix, 2896 (18.7%) had detectable LC fragments; kappa fragments in 1533 and lambda fragments in 1363. Most often, the fragments were observed in pairs, with combined molecular weight typically equaled that of the full-length monoclonal LC present in the same sample. LC fragments were observed more frequently among patients diagnosed with AL amyloidosis (118/347=34%) compared to those without the diagnosis (685/6996=10%), with an odds ratio of 4.75 (95% CI, 3.75-6.01). PAGE with Coomassie blue staining revealed bands with sizes representing LC fragments in the five M-protein samples with detectable LC fragments on Mass-Fix, while no such bands observed in those without LC fragments. Western blot using anti-kappa or anti-lambda antibodies confirmed the identity of the bands with higher molecular weight as a fragment of LC in each of the IgG/kappa and IgG/lambda samples. Conclusion Mass-Fix is able to discriminate LC fragments from intact LC based on their sizes. The detection of LC fragments with Western blot without ionization suggests a biological origin rather than analytical artifacts from MS. The clinical association study suggests that LC fragments may have utility in increasing the suspicion of AL amyloidosis in M-protein positive patients with LC fragments, potentially facilitating earlier intervention and improving patient outcomes.