Lin, Y.

Abstract Immune effector cell–associated enterocolitis (IEC-EC) has been observed after ciltacabtagene autoleucel (cilta-cel [Carvykti]) chimeric antigen receptor T-cell (CAR-T) therapy. It is associated with dismal outcomes and is poorly characterized. Here, we examined its clinical features, risk factors, and proposed management strategies. Among the 229 consecutive patients who received cilta-cel at Mayo Clinic, 9 (3.9%) presented with a nonresolving, nonbloody, grade 3 diarrhea, often requiring prolonged total parenteral nutrition. Gastrointestinal coinfections were seen in most patients. Median time from CAR-T infusion to symptom onset was 85 days (range, 35-166), and there appeared to be a latency from symptom onset to endoscopic evaluation. Histopathology findings resembling a graft-versus-host disease pattern of mucosal injury were most seen on duodenal biopsies, whereas 2 cases had patterns akin to a T-cell lymphoproliferative disorder (1 CD4+ and 1 CD8+). Independent associated factors for IEC-EC included high-risk disease as defined by the International Myeloma Society and International Myeloma Working Group, prolonged cytokine release syndrome, and antecedent delayed neurotoxicity. Response to first-line therapy comprising IV or oral corticosteroids, bile acid sequestrants, IV immunoglobulin, and antimicrobial-directed therapy was poor, with no durable responses. Biologic therapy appeared to induce durable responses in 3 of the 5 patients (2/2 vedolizumab; 1/3 infliximab); none of the responders had gastrointestinal coinfection. Early gastroenterology input for endoscopic evaluation with the inclusion of duodenal biopsy is a key component for diagnosis. Early institution of biologic therapy after failure of a short course of corticosteroids should be considered.

Abstract Gastrointestinal (GI) involvement is a clinically relevant but undercharacterized manifestation of systemic light chain amyloidosis (AL). We aimed to define the clinical spectrum, histologic patterns, and outcomes of symptomatic GI involvement in AL. We retrospectively analyzed 4396 patients with AL from 2010 to 2024, of whom 521 (11.9%) had provider-attributed symptomatic GI involvement; 66% had biopsy-proven GI AL. Symptoms most commonly included early satiety (61%), bowel irregularities (58%), nausea (35%), abdominal pain (28%), and dysphagia (23%). Autonomic neuropathy was frequent (43% clinician attributed; 23% via autonomic reflex testing) and contributed to dysmotility-related symptoms, often without GI biopsy positivity. Among 747 GI biopsies, mucosal infiltration predominated (71%) and was associated with bleeding (22% vs 9%), cachexia, and inferior survival, whereas vascular involvement was associated with lower bleeding risk. Combined involvement of mucosa, submucosa, and vessels conferred the worst prognosis (median overall survival [mOS], 2.4 vs 5.1 vs 7.8 years for 3 vs 2 vs 1 layer); mOS was 6.8 years and was primarily driven by cardiac stage and hematologic response (very good partial response [VGPR] or better: hazard ratio, 0.20; 95% CI 0.13-0.32), with more favorable outcomes in patients with isolated GI involvement. Cachexia and persistent diarrhea were the main drivers of morbidity, need for nutritional support, and GI-related mortality (odds ratio, 2.7 for the combined end point). GI bleeding rarely recurred after achieving VGPR or better. Overall, mucosal involvement, cachexia, and dysmotility define clinically meaningful GI AL and support systematic assessment of autonomic dysfunction as well as evaluation of the need for nutritional support as a GI-specific end point for AL trials.

Abstract 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.

Abstract Frailty predicts adverse outcomes in multiple myeloma (MM), yet an objective frailty biomarker is lacking. Circulating senescence-associated secretory phenotype (SASP) factors correlate with frailty and adverse outcomes in chronic diseases, but their relevance in MM is unclear. In this study, we investigated the relationship between 36 plasma SASP factors, frailty, and clinical outcomes in: (1) a historical cohort using stored specimens from 59 patients with newly diagnosed MM, and (2) a prospective cohort of 36 patients initiating new MM treatment. Several SASP factors were significantly associated with frailty after adjusting for age, sex, and body mass index; GDF-15, TNF-RI, IL-6, and IL-8 showed positive correlations with both cumulative-deficit based and physical frailty indices. Additionally, significant age-adjusted associations were observed between SASP factors and treatment outcomes, including overall survival (OS), high-grade toxicity, and healthcare utilization. We developed a 5-factor SASP model that demonstrated superior predictive performance for OS compared to chronological age, R-ISS stage, and clinical frailty, and TNF-RI alone (5-year OS AUC: 0.90). These findings highlight the association between senescence biomarkers and frailty and OS, and support further investigation of SASP factors as objective frailty biomarkers in MM.

Abstract Castleman disease (CD) is a heterogeneous group of lymphoproliferative disorders anatomically classified by distribution (unicentric CD [UCD], oligocentric CD [oligoCD], or multicentric CD [MCD]). Human herpes virus 8–negative MCD is called idiopathic MCD (iMCD), which includes clinical subtypes with varying phenotypes and responses: TAFRO (thrombocytopenia, anasarca, fever, renal dysfunction and/or reticulin fibrosis, and organomegaly), IPL (idiopathic plasmacytic lymphadenopathy), and not otherwise specified. OligoCD has recently emerged as an intermediate form between UCD and MCD, with unclear clinical behavior, and IPL has not been validated in a Western cohort. We retrospectively analyzed 217 patients with CD evaluated at our institution between January 2004 and August 2024. Survival probabilities were compared using log-rank tests. Overall, 57% had UCD, 20% had oligoCD, and 23% had iMCD. Patients with oligoCD and iMCD more frequently exhibited systemic symptoms than those with UCD. Patients with oligoCD and iMCD had significantly shorter event-free survival (EFS) of 8.9 and 2.3 years, respectively, than those with UCD (not reached; P&lt; .001 and P&lt; .02). Among iMCD subtypes, iMCD-IPL demonstrated a longer EFS than iMCD-TAFRO (P = .02), with no deaths during the follow-up periods. The results validate oligoCD and iMCD-IPL as new subtypes in this Western cohort. The survival outcome in oligoCD was intermediate between UCD and iMCD, with only a subset of patients with oligoCD requiring systemic therapy. iMCD-IPL had a favorable survival outcome in this US cohort, similar to what has been reported in non-Western countries. Tailoring treatment strategies to disease subtypes and vigilant monitoring of oligoCD for progression may improve survival outcomes in CD.