The Renal Range of the κ/λ sFLC Ratio: Best Strategy to Evaluate Multiple Myeloma in Patients With Chronic Kidney Disease

Background: Monoclonal serum free light chains (sFLC) are a well-known cause of renal impairment (RI) in patients with multiple myeloma (MM). As an indicator of monoclonality, sFLC ratio has acquired a key role in the diagnosis and monitorization of the disease. However, its interpretation is altered in patients with chronic kidney disease (CKD). This study aims to evaluate the modification of the sFLC ratio reference range in patients with CKD, and propose an optimal range for patients with CKD. Methods: Serum FLC κ/λ ratio and estimated glomerular filtration rate (eGFR) were retrospectively analyzed in 113 control patients (without hematologic disease), 63 patients with MM in complete remission and 347 patients with active MM. The three groups included patients with CKD (eGFR < 90). Results: In the group of patients without active MM (n = 176), the sFLC ratio increased at different stages of CKD without pathological significance, with an increase in the number of false positives specially when eGFR is ≤55 ml/ min. An optimal range was established for patients with eGFR ≤55 ml/min/1.73 m2: 0.82-3,6 with maximum sensitivity + specificity for that group with an improvement in the Area under the curve (AUC), 0.91 (0.84-0.97) compared with the current ranges proposed by Katzmann and Hutchinson. Conclusions: This study confirms the influence of eGFR on the interpretation of the sFLC ratio, showing a decreasing specificity in progressive CKD stages when using the reference sFLC range (Katzmann), especially in patients with eFGR ≤55. According to our results, we suggest a modified optimal range (0.82-3,6) for eGFR ≤55 ml/ min/1.73 m2. It is necessary to validate this modified range in larger and prospective studies

The avoidance of G-CSF and the addition of prophylactic corticosteroids after autologous stem cell transplantation for multiple myeloma patients appeal for the at-home setting to reduce readmission for neutropenic fever

Autologous stem cell transplantation (ASCT) remains the standard of care for young multiple myeloma (MM) patients; indeed, at-home ASCT has been positioned as an appropriate therapeutic strategy. However, despite the use of prophylactic antibiotics, neutropenic fever (NF) and hospital readmissions continue to pose as the most important limitations in the outpatient setting. It is possible that the febrile episodes may have a non-infectious etiology, and engraftment syndrome could play a more significant role. The aim of this study was to analyze the impact of both G-CSF withdrawal and the addition of primary prophylaxis with corticosteroids after ASCT. Between January 2002 and August 2018, 111 MM patients conditioned with melphalan were managed at-home beginning +1 day after ASCT. Three groups were established: Group A (n = 33) received standard G-CSF post-ASCT; group B (n = 32) avoided G-CSF post-ASCT; group C (n = 46) avoided G-CSF yet added corticosteroid prophylaxis post-ASCT. The incidence of NF among the groups was reduced (64%, 44%, and 24%; P2 (OR 6.1; P = 0.002) and G-CSF avoidance plus corticosteroids (OR 0.1; P<0.001); and for hospital readmission: age �60 years (OR 14.6; P = 0.04) and G-CSF avoidance plus corticosteroids (OR 0.07; P = 0.05. G-CSF avoidance and corticosteroid prophylaxis post ASCT minimize the incidence of NF in MM patients undergoing at-home ASCT. This approach should be explored in a prospective randomized clinical trial

Nectin-2 Expression on Malignant Plasma Cells Is Associated With Better Response to TIGIT Blockade in Multiple Myeloma

Purpose: T-cell immunoreceptor with Ig and ITIM domain (TIGIT) blockade could represent an alternative therapeutic option to release the immune response in patients with multiple myeloma. Here we analyzed the expression of TIGIT and its ligands poliovirus receptor (PVR) and nectin-2 in the bone marrow (BM) of patients with monoclonal gammopathies and the efficacy of TIGIT blockade activating antimyeloma immunity. Experimental design: Expression levels of TIGIT and its ligands were characterized by flow cytometry and ELISA. TIGIT blockade was analyzed in in vitro functional assays with peripheral T cells. BM cells were studied with NanoString technology, real-time PCR, and ex vivo patient BM cell models. Results: TIGIT and its ligands are highly expressed in the BM of patients with multiple myeloma, suggesting that may play a role in restraining immune activation. TIGIT blockade depleted FoxP3+ Tregs while increasing proliferation of IFNγ-producing CD4+ T cells from patients with multiple myeloma. PVR ligation inhibited CD8+ T-cell signaling and cell proliferation which could be overcome with anti-TIGIT mAb. However, BM cells showed a remarkable heterogeneity in immune signature. Accordingly, functional ex vivo BM assays revealed that only some patients respond to checkpoint blockade. Thus, response to TIGIT blockade correlated with low frequency of TIGIT+ cells and high nectin-2 expression on malignant plasma cells. Conclusions: TIGIT blockade efficiently reinvigorated peripheral T cells from patients with multiple myeloma. However, in the BM, the efficacy of blocking anti-TIGIT mAb to achieve tumor cell death may depend on the expression of TIGIT and nectin-2, becoming potential predictive biomarkers for identifying patients who may benefit from TIGIT blockade

Bone marrow plasma cell infiltration in light chain amyloidosis: impact on organ involvement and outcome

<p><b>Objectives:</b> Prognosis of immunoglobulin light-chain (AL) amyloidosis depends mainly on the presence of cardiac involvement and the disease burden. A higher bone marrow plasma cell (BMPC) burden has been recognized as an adverse prognostic factor. The aim of our study was to analyze the correlation between the BMPC infiltration, clinical features and outcomes in patients with AL amyloidosis.</p> <p><b>Methods:</b> The clinical records of 79 patients with AL amyloidosis treated at a single institution.</p> <p><b>Results:</b> Median BMPC infiltration at diagnosis was 11% and significantly correlated with the serum free light-chain difference (<i>p</i> < .001). Patients with more than 10% BMPCs had more frequent cardiac involvement (86 vs. 63%; <i>p</i> = .015), a trend towards a higher early mortality (27 vs. 11%; <i>p</i> = .08) and a significantly shorter progression-free survival (PFS) (median of 18 vs. 48 months, <i>p</i> = .02) and overall survival (median of 33 months vs. not reached; <i>p</i> = .046). In the multivariate analysis, a BMPC infiltration over 10% retained its adverse prognostic value for PFS (HR = 2.26; 95% CI, 1.048–4.866; <i>p</i> = .038). The use of new drugs seemed to overcome the negative prognostic impact of a higher BMPC infiltration.</p> <p><b>Conclusion:</b> Higher BMPC infiltration in AL amyloidosis might be associated with increased systemic organ damage, particularly cardiac involvement and is rarely related to the development of myeloma features.</p

Gene Expression Analysis of the Bone Marrow Microenvironment Reveals Distinct Immunotypes in Smoldering Multiple Myeloma Associated to Progression to Symptomatic Disease

Altres ajuts: This work was supported in part by Grants PI16/00423, PI19/ 00669 and PI20/00436 from Instituto de Salud Carlos III (Ministerio de Economía y Competitividad, co-funded by Fondo Europeo de Desarrollo Regional (FEDER)-Una manera de Hacer Europa) and the CERCA Programme/Generalitat de Catalunya.Background: We previously reported algorithms based on clinical parameters and plasma cell characteristics to identify patients with smoldering multiple myeloma (SMM) with higher risk of progressing who could benefit from early treatment. In this work, we analyzed differences in the immune bone marrow (BM) microenvironment in SMM to better understand the role of immune surveillance in disease progression and to identify immune biomarkers associated to higher risk of progression. Methods: Gene expression analysis of BM cells from 28 patients with SMM, 22 patients with monoclonal gammopathy of undetermined significance (MGUS) and 22 patients with symptomatic MM was performed by using Nanostring Technology. Results: BM cells in SMM compared to both MGUS and symptomatic MM showed upregulation of genes encoding for key molecules in cytotoxicity. However, some of these cytotoxic molecules positively correlated with inhibitory immune checkpoints, which may impair the effector function of BM cytotoxic cells. Analysis of 28 patients with SMM revealed 4 distinct clusters based on immune composition and activation markers. Patients in cluster 2 showed a significant increase in expression of cytotoxic molecules but also inhibitory immune checkpoints compared to cluster 3, suggesting the presence of cytotoxic cells with an exhausted phenotype. Accordingly, patients in cluster 3 had a significantly longer progression free survival. Finally, individual gene expression analysis showed that higher expression of TNF superfamily members (TNF, TNFAIP3, TNFRSF14) was associated with shorter progression free survival. Conclusions: Our results suggest that exhausted cytotoxic cells are associated to high-risk patients with SMM. Biomarkers overexpressed in patients with this immune gene profile in combination with clinical parameters and PC characterization may be useful to identify SMM patients with higher risk of progression