Citations

Abstract BACKGROUND Free light chain (FLC) quantification is the most analytically sensitive blood-based method commercially available to diagnose and monitor patients with plasma cell disorders (PCDs). However, instead of directly detecting monoclonal FLCs (mFLCs), FLC assays indirectly assess clonality based on quantifying κ and λ FLCs and determination of the к/λ FLC ratio. Often an abnormal FLC ratio is the only indication of a PCD, and confirmation by a direct method increases diagnostic confidence. The aim of this study was to develop an analytically sensitive method for direct detection of mFLCs. METHODS Patient sera (n = 167) previously assessed by nephelometric FLC quantification and immunofixation electrophoresis (IFE) were affinity enriched for IgG, IgA, and total and free κ and λ light chains and subjected to MALDI-TOF MS. Relative analytical sensitivity of these methods was determined using serially diluted sera containing mFLCs. RESULTS In sera with abnormal FLC ratios (n = 127), 43% of monoclonal proteins were confirmed by IFE, 57% by MALDI-TOF MS without FLC enrichment, and 87% with FLC enrichment MALDI-TOF MS. In sera with normal FLC ratios (n = 40), the FLC MALDI-TOF MS method identified 1 patient with an mFLC. Serial dilution and analysis of mFLC containing sera by IFE, nephelometry, and FLC MALDI-TOF MS demonstrated that FLC MALDI-TOF MS analysis had the highest analytical sensitivity. CONCLUSIONS FLC immunoenrichment coupled to MALDI-TOF MS enables direct detection of mFLCs and significantly increases the confirmation of abnormal serum FLC ratios over IFE and MALDI-TOF MS without FLC enrichment, thereby providing added confidence for diagnosing FLC PCDs.

6594 Background: Given the significant short-term adverse effects of CAR-T cell therapy, it is important to evaluate its impact on QOL of patients in addition to efficacy, compared with established forms of cellular therapy like SCT. Methods: QOL was evaluated prospectively in patients undergoing CAR-T therapy, autoSCT & alloSCT for hematologic malignancies. QOL was assessed with FACT-G at baseline, 2 weeks and monthly for 6 months thereafter. Functional well-being (FWB), physical WB (PWB) emotional WB (EWB) & social WB (SWB) and change over time were compared across groups. Results: 45 patients were recruited (CAR-T: 10; Auto SCT: 22; Allo SCT: 13) with follow up for 2 weeks & 1 month available for 23 &15 patients, respectively (Table). There was no statistically significant difference in baseline total QOL scores (p=0.13), though scores were lower in the alloSCT group (85,84,68). EWB &FWB were numerically higher in the CAR-T group, followed by autoSCT group. At 2 weeks, overall QOL decreased by only 2 points in CAR-T group vs. 22 & 18 points in auto & alloSCT groups (p=0.09). Change in PWB vs. baseline was less pronounced in the CAR-T group (-1, -9, -13, p=0.03). At 1 month, overall QOL was 6 points lower than baseline in CAR-T group vs. 3 and 14 points lower in auto & alloSCT groups, respectively (p=0.34). Importantly, PWB had at least returned to baseline in the CAR-T group. Conclusions: Preliminary data show that patients undergoing CAR-T cell therapy do not experience a more significant decline in QOL compared with auto & allo SCT, and may experience fewer physical side effects in the short-term. Accrual & follow-up are ongoing. [Table: see text]

In this paper, we present our preliminary findings regarding magnetic resonance elastography (MRE) on the livers of 10 patients with systemic amyloidosis. Mean liver stiffness measurements (LSM) and spleen stiffness measurements (SSM) were obtained. Magnetic resonance imaging (MRI) images were analyzed for the distribution pattern of amyloid deposition. Pearson correlation analysis was performed in order to study the correlation between LSM, SSM, liver span, liver volume, spleen span, spleen volume, serum alkaline phosphatase (ALP), N-terminal pro b-type natriuretic peptide (NT pro BNP), and the kappa and lambda free light chains. An increase in mean LSM was seen in all patients. Pearson correlation analysis showed a statistically significant correlation between LSM and liver volume (r = 0.78, p = 0.007) and kappa chain level (r = 0.65, p = 0.04). Interestingly, LSM did not correlate significantly with SSM (r = 0.45, p = 0.18), liver span (r = 0.57, p = 0.08), or serum ALP (r = 0.60, p = 0.07). However, LSM correlated significantly with serum ALP when corrected for liver volume (partial correlation, r = 0.71, p = 0.03) and NT pro BNP levels (partial correlation, r = 0.68, p = 0.04). MRI review revealed that amyloid deposition in the liver can be diffuse, lobar, or focal. MRE is useful for the evaluation of hepatic amyloidosis and shows increased stiffness in hepatic amyloidosis. MRE has the potential to be a non-invasive quantitative imaging marker for hepatic amyloidosis.

AbstractDisease OverviewPolyneuropathy, organomegaly, endocrinopathy, M‐protein, skin changes (POEMS) syndrome is a paraneoplastic syndrome due to an underlying plasma cell neoplasm. The major criteria for the syndrome are polyradiculoneuropathy, clonal plasma cell disorder (PCD), sclerotic bone lesions, elevated vascular endothelial growth factor, and the presence of Castleman disease. Minor features include organomegaly, endocrinopathy, characteristic skin changes, papilledema, extravascular volume overload, and thrombocytosis. Diagnoses are often delayed because the syndrome is rare and can be mistaken for other neurologic disorders, most commonly chronic inflammatory demyelinating polyradiculoneuropathy. POEMS syndrome should be distinguished from the Castleman disease variant of POEMS syndrome, which has no clonal PCD and typically little to no peripheral neuropathy but has several of the minor diagnostic criteria for POEMS syndrome.DiagnosisThe diagnosis of POEMS syndrome is made with three of the major criteria, two of which must include polyradiculoneuropathy and clonal PCD, and at least one of the minor criteria.Risk StratificationBecause the pathogenesis of the syndrome is not well understood, risk stratification is limited to clinical phenotype rather than specific molecular markers. Risk factors include low serum albumin, age, pleural effusion, pulmonary hypertension, and reduced eGFR.Risk‐Adapted TherapyFor those patients with a dominant sclerotic plasmacytoma, first line therapy is irradiation. Patients with diffuse sclerotic lesions or disseminated bone marrow involvement and for those who have progression of their disease 3 to 6 months after completing radiation therapy should receive systemic therapy. Corticosteroids are temporizing, but alkylators are the mainstay of treatment, either in the form of low dose conventional therapy or high dose with stem cell transplantation. Lenalidomide shows promise with manageable toxicity. Thalidomide and bortezomib also have activity, but their benefit needs to be weighed against their risk of exacerbating the peripheral neuropathy. Prompt recognition and institution of both supportive care measures and therapy directed against the plasma cell result in the best outcomes.