Anemia of inflammation (AI) is the second most common form of anemia and is prevalent in patients with chronic inflammatory states, such as infection, autoimmunity, and cancer. Interleukin 6 (IL-6) is well-known to induce the iron-sequestering hormone hepcidin, which results in iron-restricted anemia. The contributions of other proinflammatory cytokines, such as tumor necrosis factor-α (TNFα) and interferon gamma (IFNγ), are less understood in the pathophysiology of AI. This study investigated the role of TNFα in a mouse model of AI by administering heat-killed Brucella abortus (HKBA) to germ line TNFα knockout (KO) mice. We hypothesized that TNFα possessed an important role in restoring steady-state erythropoiesis after inflammatory insult. TNFαKO injected with HKBA displayed a chronic anemia, with elevated proinflammatory IL12p40 and IFNγ cytokines that did not resolve. However, IFNγKO and TNFαKO/FNγKO double knockout mice showed reduced inflammation and anemia following HKBA administration. Because IFNγKO displayed normal serum TNFα and IL12p40 levels, we hypothesized that the persistent anemia was IFNγ induced and TNFα was necessary for AI cessation. However, treatment with recombinant TNFα (rTNFα) accelerated death, while reducing IFNγ using an anti-IFNγ antibody (Ab) only briefly improved anemia. Only the combination of both the Ab and rTNFα together reversed the hyperinflammatory phenotype, restored erythropoiesis, and prevented death of TNFαKO + HKBA mice. Our data provide compelling evidence for an anti-inflammatory role of TNFα that is necessary for the restoration of erythropoiesis and mitigation of proinflammatory IFNγ action in a mouse model of AI.

An acute inflammatory response to infection or sterile injury involves an adequate activation and recruitment of leukocytes. Activation of β2-integrins is required for neutrophil recruitment and is also mandatory for various neutrophil cell-intrinsic functions. Guanosine triphosphatases (GTPases) are key regulators of the actin cytoskeleton and are required for β2-integrin activation. Myosin-IXb (Myo9b), a Rho GTPase-activating protein, is essential for regulating Rho activity in neutrophils. Yet, the exact molecular mechanism through which Myo9b regulates β2-integrin activity and neutrophil recruitment into inflamed tissue is unknown. We demonstrate that Myo9b deficiency causes RhoA overactivation, increases actin cytoskeleton rearrangement in neutrophils, decreases neutrophil recruitment into the kidney, and improves kidney function in murine models of acute kidney injury. Loss of Myo9b also affects neutrophil effector functions and causes increased rolling velocity, decreased adhesion, impaired crawling, and strongly reduced transmigration of neutrophils in vivo. Mechanistically, Myo9b regulates RhoA activity, which is required for chemokine- and selectin-induced talin-1 recruitment to β2-integrins. Thus, Myo9b is a crucial regulator of important signaling pathways in neutrophils and is required for an adequate immune response triggered by chemokines and selectins.

Rapid CD137 upregulation on alloreactive T cells upon allogeneic stimulation suggests that their selective elimination could prevent acute graft-versus-host disease (aGVHD) after allogeneic hematopoietic stem cell transplantation (HCT). Here, we developed a novel aGVHD prophylactic regimen consisting of a single dose of an anti-CD137 antibody-drug conjugate (CD137-ADC) administered on the day of transplant without additional immunosuppression. The CD137-ADC depleted both human and nonhuman primate (NHP) activated T cells and proved highly effective in preventing xenogeneic aGVHD in mice receiving human peripheral blood mononuclear cells, as well as in NHP undergoing major histocompatibility complex (MHC)-haploidentical HCT. Flow cytometry analysis of NHP T cells indicated specific depletion of activated PD-1+ CD4 and CD8 T cells, while sparing naïve and PD-1-OX40+ memory T-cell subsets during the first week after HCT. CD137-ADC-treated NHP recipients demonstrated robust hematopoietic and immune reconstitution. Hallmarks of T-cell recovery after CD137-ADC, which were associated with long-term aGVHD-free survival, included reconstitution of CD4 memory T cells expressing TRAIL, terminally differentiated CD8 T cells expressing CX3CR1, and CD4 FoxP3+ regulatory T cells, cell types not expected to be involved in aGVHD pathogenesis. CD137-ADC-treated recipients demonstrated a higher risk of reactivation of rhesus lymphocryptovirus (the rhesus macaque Epstein-Barr virus analog), which was associated with reconstitution of follicular helper T cells, interferon signaling-associated memory, and γδT-cell subsets. This reactivation was controllable with rituximab administration. These results document effective depletion of alloreactive T cells and prevention of aGVHD after a single dose of CD137-ADC, suggesting that clinical translation should be carefully explored.

Cellular therapies targeting B-cell maturation antigen have shown promise in controlled clinical trials, but their impact in broader, diverse patient populations remains underexplored. This study examines the real-world efficacy and safety in 343 triple-class-exposed patients with relapsed and refractory multiple myeloma who received idecabtagene vicleucel (ide-cel; n = 266) or ciltacabtagene autoleucel (cilta-cel; n = 77) after >3 previous lines of therapy in Germany. Cilta-cel, compared with ide-cel, demonstrated superior outcomes, achieving a higher overall response rate (94% vs 82%) and 10-month progression-free survival (PFS; 76% vs 47%). Cilta-cel also led to higher complete response (CR; 61% vs 39%) and improved response conversion, with more patients achieving CR after starting from less than CR before chimeric antigen receptor T-cell (CAR T) therapy. For those attaining CR after therapy, cilta-cel showed longer PFS, especially in patients who entered treatment with a partial response or worse. Cytokine release syndrome was observed in 85% of cilta-cel and 81% of ide-cel cases, predominantly low grade. Immune effector cell-associated neurotoxicity syndrome was more common with cilta-cel (25% vs 15%), although nonrelapse mortality at 10 months was comparable between therapies (7% vs 5%). Weighted multivariable analysis after propensity score matching confirmed a significant advantage in terms of PFS for cilta-cel, with a hazard ratio of 0.48. Overall, outcomes in our registry analysis were comparable with the pivotal trials that led to approval of the respective agents. Cilta-cel demonstrated a greater capacity for response conversion and durable remission. These findings underscore the need for individualized CAR T therapy selection to optimize patient outcomes.

CD19-directed chimeric antigen receptor (CAR) T-cell therapy has revolutionized the treatment of relapsed/refractory B-cell non-Hodgkin lymphoma (B-NHL) and recently showed effects in autoimmune diseases, such as systemic lupus erythematosus (SLE). Despite high levels of inflammation, toxicity seemed to differ between patients with SLE and B-NHL. We therefore compared the CAR T-cell kinetics and treatment-related side effects to better define the toxicity profiles. In contrast with the similar CAR T-cell expansion, patients with SLE revealed a lower incidence and severity of cytokine-release syndrome, immune effector cell-associated neurotoxicity syndrome, and immune effector cell-associated hematotoxicity. Although the neutrophil nadir was lower in patients with SLE after therapy, the platelet counts remained close to normal and hematotoxicity was shorter in SLE than B-NHL. The reduced hematotoxicity correlated with lower acute-phase inflammation, better hematologic reserve before CAR T-cell therapy, and distinct serum cytokine profiles. Interestingly, CAR T-cell persistence was consistently shorter, and the reconstitution of conventional T and B cells was faster in SLE. In both cohorts, B-cell reconstitution correlated with functional CD4+ T-cell recovery, indicating a general biologic process of hematopoietic and immune system regeneration. In summary, similar lymphodepletion and CAR T-cell pharmacokinetics led to distinct toxicity, demonstrating that CAR T-cell therapy had a favorable side-effect profile in SLE, including faster recovery of the adaptive immune system.

Clonal hematopoiesis of indeterminate potential (CHIP) is associated with increased mortality and malignancy risk, yet the determinants of clonal expansion remain poorly understood. We performed sequencing at a depth of coverage of >4000× for CHIP mutations in 6976 postmenopausal women from the Women's Health Initiative (WHI) at 2 time points: the WHI baseline examination and ∼16 years later at the Long Life Study (LLS) visit. Among 3685 CH mutations detected at baseline (variant allele fraction [VAF] of ≥0.5%), 24% were not detected at LLS, 26% were micro-CH at LLS (0.5% ≤ VAF < 2%), and 50% were CHIP (VAF ≥ 2%). We confirmed that clonal expansion is highly dependent on initial clone size and CHIP driver gene, with SF3B1 and JAK2 mutations exhibiting the fastest growth rate. We identified germ line variants in TERT, IL6R, TCL1A, and MSI2 that modulate clonal expansion rate. Measured baseline leukocyte telomere length showed differential effects on incident CHIP risk, with shorter baseline leukocyte telomere length predisposing to incident PPM1D mutations and longer baseline leukocyte telomere length favoring incident DNMT3A mutations. We discovered that the IL6R missense variant p.Asp358Ala specifically impairs TET2 clonal expansion, supported by direct measurements of soluble interleukin-6 receptor and interleukin-6. Faster clonal growth rate was associated with increased risk of cytopenia, leukemia, and all-cause mortality. Notably, CHIP clonal expansion rate mediated 34.4% and 43.7% of the clonal hematopoiesis risk score's predictive value for leukemia and all-cause mortality, respectively. These findings reveal key biological determinants of CHIP progression and suggest that incorporating growth rate measurements could enhance risk stratification.

Patients with follicular lymphoma who experience disease progression within 24 months of diagnosis (POD24) have a lower survival. Positron emission tomography (PET) response and circulating tumor DNA (ctDNA) minimal residual disease (MRD) assessment at end of induction (EOI) may allow their early identification. A representative cohort of 141 patients from the RELEVANCE phase 3 trial with both available serum samples for ctDNA testing and PET images at randomization and at EOI (week 24) was investigated. Twelve percent were POD24. ctDNA was analyzed using a customized 130-kilobase capture panel, with phased variant (PV) enriched regions representing 39% of the panel. ctDNA was detected in 140 patients (99.3%) at baseline. To optimize specificity, only PVs, found in 124 patients (88%), were considered for ctDNA MRD assessment at EOI. Median progression-free survival (PFS) from EOI was not reached (NR) for the 112 patients with undetected ctDNA at EOI vs 17.7 months (95% confidence interval [CI], 1.4 to NR) for patients with positive ctDNA (MRD+) (P = .0038). Similarly, median PFS was NR for the 104 patients with undetected disease on PET at EOI vs 28.3 months (95% CI, 2.9 to NR; P = .0002) for patients with PET positivity. Both tests had a negative predictive value (NPV) of >90% for POD24. The positive predictive value was 58.3% for ctDNA MRD and 45% for PET but increased to 85.7% when both parameters were combined, without alteration of NPV. These data show that the combination of PET response and ctDNA MRD at EOI allows an early prediction of POD24, which may lead to a preemptive treatment decision. This trial was registered at www.clinicaltrials.gov as #NCT01650701.

In retrospective studies, autologous stem cell transplantation (ASCT) conditioning with intravenous busulfan and melphalan (BUMEL) led to longer progression-free survival (PFS) than melphalan alone (MEL200). We compared long-term outcomes of BUMEL vs MEL200 in the context of intensified bortezomib, lenalidomide, and dexamethasone (VRD) induction and consolidation therapies. GEM12 was a phase 3 trial for patients with newly diagnosed multiple myeloma (NDMM) eligible for ASCT including 6 reinforced VRD cycles followed by ASCT conditioned with BUMEL or MEL200 and 2 VRD consolidation cycles. The primary end point was PFS. Subgroup analyses were based on International Staging System (ISS) stages and high-risk genetic abnormalities. Patients were randomized with an open-label 2 × 2 factorial design and 1:1:1:1 allocation ratio to ensure the balance between the GEM12 and the subsequent phase 3 GEM14 trial. Between 2013 and 2015, 458 patients were randomized (BUMEL, n = 230; MEL200, n = 228). The 10⁻⁶ MRD-negative rate was 63%, 68% for BUMEL vs 58% for MEL200 (odds ratio, 1.51; P = .035). The median PFS was 89 months for BUMEL and 73.1 for MEL200 (hazard ratio, 0.89 [95% confidence interval, 0.70-1.14]; P = .3). BUMEL showed benefit for patients with ISS stages II or III, t(14;16), and del(1p). For subcohorts ISS stages II or III treated with BUMEL and ISS I treated with MEL200 the median PFS was 96.5 months (95% confidence interval, 76 to not estimable). No safety concerns were observed. After a median follow-up of 8.4 years, GEM2012 demonstrated one of the longest PFS values reported in patients with NDMM, with significant differences favoring BUMEL in advanced ISS stages. The trial was registered at www.ClinicalTrials.gov as #NCT01916252 and at European Union Drug Regulating Authorities Clinical Trials as EudraCT 2012-005683-10.