Free Kappa Research Articles

Free Kappa light chain in a sample of Egyptian multiple sclerosis patients (a pilot study)

BackgroundMultiple sclerosis is a chronic autoimmune-mediated demyelinating disease of the central nervous system that is usually associated with varying degrees of progressive disability. Free Kappa light chain (FKLC) has attracted growing attention as a significant diagnostic marker of MS. Our aim was to study the diagnostic utility of cerebrospinal fluid free Kappa light chain and related indices in a sample of Egyptian MS patients vs. CSF IgG oligoclonal bands. It was a prospective case–control study of MS patients carried in our hospital during the period from January 2021 till January 2022. Our study carried on 30 patients with multiple sclerosis and other inflammatory neurologic diseases and 20 age and sex matched controls. The study measured FKLC in the CSF and serum sample pairs of patients and control group. Indices calculated using FKLC measured in CSF and serum included; FKLC index, FKLC intrathecal fraction and quotient of FKLC. Indices were used to assess intrathecal synthesis of FKLC considering blood–CSF barrier function. Receiver operating characteristic curve analysis was used to determine diagnostic performance of FKLC and related indices in comparison to CSF–OCB testing.ResultsMeasured FKLC levels as well as its calculated indices have shown statistically significant higher values among MS patients against OIND patients and healthy control group. Both FKLC index and FKLC IF were similarly showing 100% diagnostic sensitivity and 100% diagnostic specificity for MS diagnosis.ConclusionsFKLC biomarkers are proposed to be highly sensitive and easy to detect first-line markers of intrathecal immunoglobulin synthesis with accurate performance and low cost that might prove to be promising diagnostic markers of MS.

B-089 Pseudo-clonal Increased IgG4 with Polyclonal Distribution Demonstrated by MALDI-TOF-MS in a Pediatric Patient with Tricho-Hepato-Enteric Syndrome (THES)

Abstract Background THES is a rare autosomal recessive syndromic enteropathy caused by pathogenic variants in two genes, the Tetratricopeptide Repeat Domain 37 (TTC37) and Ski2 Like RNA Helicase (SKIV2L), that encode components of the human SKI complex involved in RNA degradation. This disease is characterized by several clinical features with variable penetrance including intractable congenital diarrhea, wooly hair abnormalities, intrauterine growth restriction, facial dysmorphism, immune dysfunction, liver abnormalities, and skin hyperpigmentation. Hypogammaglobulinemia with low IgG and normal to low IgM levels have been described in these cases which may require intravenous immunoglobulin (IVIG) replacement therapy. Some cases have a reduced population of switched memory B cells, T cells with reduced IFN-γ secretion, and hyporesponsive NK cells. Our patient is a 4-year-old female reported to have a homozygous TTC37 mutation with clinical manifestations of TPN dependence, liver fibrosis with portal hypertension, splenomegaly, developmental delay, thrombocytopenia and anemia requiring transfusion, and a history of hypogammaglobinemia requiring IVIG replacement. Patient would go on to develop elevated immunoglobin levels leading to additional testing described below. Methods Serum total protein analysis performed using the using Siemens Atellica CH Total Protein II test (Weichselbaum method using biuret reagent). Serum immunoglobin (IgA, IgG and IgG), IgG subclass, and kappa/lambda free light chain level analysis performed by turbidimetric photometry assay using a Binding Site Optilite analyzer. Serum protein electrophoresis and immunotyping performed using CAPILLARYS 2 capillary zone electrophoresis and immunosubtraction with antisera. Serum protein immunofixation performed using Sebia Hydrasys 2 with Hydragel 9 IF Maxi kit. Confirmation and final determination of serum immunoproteins performed at our reference laboratory using MASS-FIX (MALDI-TOF MS) matrix-assisted laser desorption/ionization-time of flight mass spectrometry after patient serum applied to 5 separate immunoaffinity resins specific to immunoglobulin G, A, M, K, and L for purification. Results Initial testing showed a broadly migrating beta-gamma region IgG kappa monotypic restriction measuring 1.7 g/dL, with predominantly kappa subtraction and trivial lambda subtraction by immunosubtraction; serum free kappa/lambda light chain ratio was increased at 22.94. Serum immunoglobins and free light chains measured (mg/dL): IgA 738 (15 - 160), IgM 48 (50 - 240), IgG 2,805 (405 - 1,160), free kappa 20.42 (0.33 - 1.94), and free lambda 0.89 (0.57 - 2.63). IgG subclasses measured (mg/dL): IgG1 533 (320 - 950), IgG2 174 (50 - 340), IgG3 16.9 (10.0 - 120.0), IgG4 1,221.1 (2.0 - 110.0). Additional serum protein values included (g/dL): total protein 8.10 (6.00 - 8.30), albumin 2.97 (3.43 - 4.84), alpha-1 0.32 (0.21 - 0.44), alpha-2 0.52 (0.54 - 0.97), beta globulin 3.42 (0.65 - 1.03), and gamma globulin 0.87 (0.70 - 2.30). The polyclonal nature of the IgG4 spike was later demonstrated by the MASS-FIX mass spectrograph. Conclusions MASS-FIX is a useful addition to the toolset used in the diagnosis of possible monoclonal gammopathies and protein disorders, especially where broad monotypic restrictions are observed or in patients with abnormal presentations for monoclonal gammopathies. Using current standard techniques, the above case could have been incorrectly classified as a monoclonal process resulting in unnecessary cost and incorrect treatment.

Diagnostic value of kappa free light chain and kappa index in Multiple Sclerosis: a systematic review and meta-analysis

Diagnostic value of kappa free light chain and kappa index in Multiple Sclerosis: a systematic review and meta-analysis

Evaluating the complement C1q levels in serum and cerebrospinal fluid in multiple sclerosis patients: Could it serve as a valuable marker in clinical practice?

Immunohistochemical studies have identified complement component C1q in MS lesions. We aimed to compare serum (sC1q) and CSF (csfC1q) levels in a large cohort of MS patients (pwMS) (n = 222) with those of healthy controls (HC, n = 52), individuals with other immune (IND, n = 14), and non-immune neurological disorders (nIND, n = 15), and to analyze their correlation with other biomarkers.pwMS were divided into three series based on their origin. CSF samples were unavailable for HC. All three pwMS cohorts had lower sC1q levels compared to HC and IND. csfC1q was higher in one pwMS cohort, with a trend in another, and correlated with IgG, Free Kappa Light Chains, GFAP, and Chitinase-3 Like Protein-1 in CSF. Our findings suggest a significant role for C1q in MS pathophysiology, potentially serving as a biomarker for disease identification.

Implications of monoclonal gammopathy and isoelectric focusing pattern 5 on the free light chain kappa diagnostics in cerebrospinal fluid.

Oligoclonal bands (OCB) analysis is the reference standard for detecting an intrathecal IgG synthesis. Alongside OCB, free light chains kappa (FLCκ) are considered an additional sensitive biomarker for determining patterns 2 or 3, indicating intrathecal Ig synthesis. However, kFLC IF is not suitable for detecting a monoclonal pattern 5. The primary aim of this study was to evaluate the impact of incorporating FLCκ analysis into routine cerebrospinal fluid (CSF) diagnostics instead of OCB testing on the rate of missed monoclonal IgG detection. A two-center retrospective biomarker study was conducted. OCB were identified using isoelectric focusing in polyacrylamide gels followed by silver staining or in agarose gels followed by immunofixation. FLCκ were quantified using nephelometry and FLCκ assay (Siemens). Out of a combined total of 17,755 OCB analyses conducted between 2011 and 2021, a subset of 269 cases (1.5 %) exhibited pattern 5. 98 samples (36 %), which included 18 samples with intrathecal inflammation as determined by additional OCB pattern 2 were included in the FLCκ analysis. Of those, 16 (89 %) had intrathecal FLCκ synthesis. While FLCκ offers a promising avenue for detecting an intrathecal inflammation, the pattern 5, though rare, remains a valuable additional finding of OCB analysis. A combined approach of FLCκ and OCB analysis is recommended for a comprehensive assessment of the humoral intrathecal immune response.

Diagnostic Utility of Free Kappa Light Chain Index in Egyptian Multiple Sclerosis Patients

Abstract Background Multiple sclerosis (MS) is a chronic autoimmune-mediated demyelinating disease of the central nervous system (CNS) that is usually associated with varying degrees of progressive disability. Free Kappa light chain (FKLC) has attracted growing attention as a significant diagnostic marker of MS. Aim of the Work The aim of this work was to study the diagnostic utility of free kappa light chain index in a sample of Egyptian MS patients versus IgG oligo clonal bands (OCBs) in CSF and serum in an attempt to throw light on a new simpler non subjective potential diagnostic marker in MS. Patients and Methods This was a case control study of MS patients carried at Ain Shams University Hospitals during the period from January 2021 till January 2022. Subjects included in this study were 30 patients with symptoms suggestive of MS yet undiagnosed and 20 controls, on the basis of their MRI findings, clinical presentation and according to the revised McDonald criteria 2017. Accordingly, patients were diagnosed as MS including 4 CIS patients, 18 RRMS patients and 3 PPMS patients and non-MS including 2 NMO patients, 1 ADEM patient, 1 APS and 1 SLE patient. They were 8 males and 22 female patients, their age ranged from 20 to 40 years old with mean 30.13 ± 6.85 SD. The control group included 5 males and 15 females; their ages ranged from 20 to 40 years with mean 30.13 ± 6.85 SD. Results We found a statistically significantly higher FKLC index and FKLC IF among MS patients in comparison to both control and non-MS group. it could be used for diagnosis of MS with a diagnostic sensitivity of 100 % and a diagnostic specificity of 100 %. Conclusion The significant association between FKLC index and MS led us to conclude FKLC index can be used as a promising diagnostic marker of MS.

Paraproteinaemic keratopathy simulating a crystalline keratopathy

BackgroundParaproteinemic keratopathy is a rare disorder characterized by the bilateral accumulation of polychromatic deposits diffusely in all corneal layers together or not with diffuse or patchy pseudo lipid deposits. We present an atypical case of paraproteinemic keratopathy which lead to an initial misdiagnosis of infectious crystalline keratopathy.Case presentationa 69-year-old woman with an asymptomatic keratopathy detected during a cataract intervention. Slit-lamp examination revealed several hyper refringent subepithelial foci with fern-shaped branches, resembling crystalline keratopathy, in her left eye. Anterior segment optical coherence tomography revealed exclusively subepithelial hyperreflective lesions limited to the anterior stroma. The progressive bilateralization and progression of the condition prompted us to include other entities with crystalline corneal deposits in our differential diagnosis. Hematological analysis showed a high number of free Kappa light chains. Despite the typical clinical appearance of crystalline keratopathy, the atypical evolution and test results led us to consider that monoclonal gammopathy could be the cause of this entity.ConclusionsParaproteinemic keratopathy may present in its early stages as a unilateral subepithelial crystalline keratopathy. Thus, it must always be taken into account in the differential diagnosis of any crystalline keratopathy, particularly when there are no predisposing factors for an infectious crystalline keratopathy. Early recognition of this rare entity is important to address the associated potentially serious systemic disease.

Predictive potential of serum and cerebrospinal fluid biomarkers for disease activity in treated multiple sclerosis patients

Background: Our objective was to explore various biomarkers for predicting suboptimal responses to disease-modifying treatments (DMTs) in patients with MS (pwMS).Methods: We conducted a longitudinal, bicentric study with pwMS stratified based on their DMTs responses. Treatment failure (TF) was defined as the onset of a second relapse, presence of two or more T2 new lesions, or disability progression independent of relapse during the follow-up period. We evaluated intrathecal synthesis (ITS) of IgG and IgM using OCB, linear indices, and Reibergrams. Free kappa light chains ITS was assessed using the linear index (FKLCi). NfL and GFAP in serum and CSF, and CHI3L1 in CSF were quantified. Quantitative variables were dichotomized based on the third quartile. Predictive efficacy was assessed through bivariate and multivariate analyses, adjusting for age, sex, EDSS, acute inflammatory activity (AI) -defined as the onset of a relapse or gadolinium-enhancing lesions within a 90-day window of lumbar puncture-, treatment modality, study center, and time from disease onset to treatment initiation. In case of collinearity, multiple models were generated or confounding variables were excluded if collinearity existed between them and the biomarker. The same methodology was used to investigate the predictive potential of various combinations of two biomarkers, based on whether any of them tested positive or exceeded the third quartile.Results: A total of 137 pwMS were included. FKLCi showed no differences based on AI, no correlation with EDSS and was significantly higher in pwMS with TF (p = 0.008). FKLCi>130 was associated with TF in bivariate analysis (Log-Rank p = 0.004). Due to collinearity between age and EDSS, two different models were generated with each of them and the rest of the confounding variables, in which FKLCi>130 showed a Hazard Ratio (HR) of 2.69 (CI: 1.35–5.4) and 2.67 (CI: 1.32–5.4), respectively. The combination of either FKLC or sNfL exceeding the third quartile was also significant in bivariate (Log-Rank p = 0.04) and multivariate (HR=3.1 (CI: 1.5–6.5)) analyses. However, when analyzed independently, sNfL did not show significance, and FKLCi mirrored the pattern obtained in the previous model (HR: 3.04; CI: 1.51–6.1). Treatment with highefficacy DMTs emerged as a protective factor in all models.Discussion: Our analysis and the fact that FKLCi is independent of EDSS and AI suggest that it might be a valuable parameter for discriminating aggressive phenotypes. We propose implementing high-efficacy drugs in pwMS with elevated FKLCi.

Can we really rely on the free light chains kappa quotient for detecting intrathecal humoral immune response?

Can we really rely on the free light chains kappa quotient for detecting intrathecal humoral immune response?

EFFECT OF CHRONIC FUROSEMIDE THERAPY ON SERUM FREE LIGHT CHAIN IN CHRONIC KIDNEY DISEASE PATIENTS

Objective: Chronic kidney disease (CKD) is an important cause of morbidity and mortality worldwide. There is a lack of information on the epidemiology and progression of CKD in low-middle-income countries. Chronic use of diuretics is considered to further decrease renal clearance, a pathophysiology not very clearly understood. Free light chains renal deposition is precipitated by loop diuretics. This study attempted to determine whether chronic diuretic usage was associated with increase serum free light chain and a reduction in renal clearance among CKD patients. Design and method: A single-center, record-based study of 84 CKD patients with an established diagnosis of CKD, loop diuretic therapy, between June 2019 and December 2019 was conducted after ethical approval by institutional ethics committee ((RIMS/2018/32). The study included participants with age above 18 years of age, never dialysed, non-neoplastic (specifically plasma cell disorder), non-pregnant, and those on loop diuretic were divided into 3 groups: group 1 with Furosemide exposure more than 6 months; Group 2 with furosemide exposure between 3 months to 6 months but less than 6 months; and Group 3 with furosemide exposure less than 3 months. Results: 46 out of 84 patients were of group 1, 20 belonged to group 2 and 18 were in group 3. In group 1, mean eGFR of 103.6, mean free kappa of 100.98 and mean lambda of 126.65.2 was observed. Group 2 patients had mean eGFR of 125.6 with mean free kappa of 80.98 and mean lambda of 1002.2, whereas group 3 had mean eGFR of 15 5.5, mean free kappa of 79.8 and mean lambda of 96.65.2. It was also observed that 98% patients with stage 5 CKD had high serum free lambda level. Conclusions: This study revealed a strong association of serum free light chain level with stage of CKD in patients on diuretic therapy. Therefore, monitoring of Serum Free Light Chain among CKD patients on diuretic therapy can be an indirect evidence of furosemide induced renal function worsening.

Abstract 4807: Gaucher disease treatment reduces the progression of smoldering myeloma

Abstract Background: Gaucher disease (GD), a hereditary condition characterized by glucocerebrosidase deficiency, results in the impaired degradation of glucocerebroside (GL1) and its deacetylated form, lyso-GL1 (LGL1). This leads to the accumulation of these substrates primarily in the bone marrow (BM), liver, and spleen. Notably, individuals with GD face an increased risk of plasma cell dyscrasias (PCD) by approximately nine-fold. We present two compelling cases of the regression of smoldering multiple myeloma (SMM) following GD treatment, substantiated by biochemical evidence of lipid-reactive clonal paraproteins (PP) in both patients. Methods: Peripheral blood samples were obtained with IRB approval from patients with concurrent SMM and GD at the Icahn School of Medicine at Mount Sinai. Utilizing C-18 beads coupled with gly-sphingosine-coated liposomes and Sphingosine-1 phosphate bead liposome-based pulldown, we established the binding of glycolipids to serum PP. Results: In a 66-year-old male, hepatosplenomegaly and pancytopenia revealed compound heterozygous N370S/V394L mutations and reduced β-glucosidase activity, confirming Type 1 GD. Laboratory findings included substantial pancytopenia (WBC 2.5 k/µL, Hgb 12.1 g/dL, platelet 44 k/µL) and myeloma markers (M spike 1.58 g/dL, monoclonal IgA λ). A BM biopsy indicated 30% λ-restricted plasma cells. PET-CT showed hepatosplenomegaly without FDG avid lytic lesions, consistent with SMM. Imiglucerase enzyme therapy improved GD biomarkers, decreased hepatosplenomegaly, and blood count improvement (WBC 4.7 k/µL, Hgb 13.6 g/dL, platelet 66 k/µL). Notably, myeloma burden significantly reduced (M-spike 0.94 g/dL, IgA 1373 g/dL and free lambda 26.1 mg/L). Similarly, a 41-year-old female with mild fatigue, Hgb levels of 10.9 g/dL, a platelet count of 169 k/µL, M spike of 0.9 g/dL, IgG κappa on immunofixation, and IgG levels at 1730 mg/dL, indicating SMM. GBA analysis showed homozygous N370S mutation and reduced beta-glucosidase activity consistent with Type 1 GD. Substrate reduction therapy with eliglustat alleviated fatigue, reduced GD biomarkers, normalized cytopenias, and gradually decreased myeloma markers. Laboratory results indicated an M spike of 0.5 g/dL, IgG levels at 1295 mg/dL, and free kappa at 31.3 mg/L. To explore the interaction between clonal immunoglobulins (Ig) and lyso-lipids, we utilized Gly-sphingolipids (see methods) and demonstrated a robust interaction with IgA (patient 1) and IgG (patient 2) paraprotein by western blotting. Conclusion: Our experimental findings confirm specific clonal Ig binding in SMM and GD patients and demonstrate potent and timely benefits from addressing GD in managing SMM patients. This holds significance amid ongoing clinical trials exploring aggressive interventions for SMM, including bispecific and CAR-T therapies. Citation Format: Ravi Prakash Shukla, Anshuman Parekh, Violetta V Leshchenko, Kevin Barley, Deepa Vatti, Daniel Verina, Manisha Balwani, Samir Parekh. Gaucher disease treatment reduces the progression of smoldering myeloma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4807.

The correlation between serum free light chain levels and plasma cell ratio in bone marrow biopsy in multiple myeloma

Aims: MM (Multiple myeloma) is the second most common hematological malignancy. In addition to the recent advances in treatment, new parameters are used in clinical practice in diagnosis and follow-up. sFLC (free chain kappa and lambda) shows the activation of the disease depending on the rate of MM malignant cell secretion in serum. However, the plasma cell (PC) ratio in bone marrow biopsy is still the gold standard in diagnosis. We examined the dynamic correlation between the PC ratio and the number of sFLC-related cells and the secretion rate. We aimed to examine whether a low PC ratio could be in a more aggressive form with a higher sFLC secretion with too much activity, thus examining the correlation between them.
 Methods: A total of 62 newly diagnosed MM patients admitted to Başkent University Faculty of Medicine İstanbul Hospital were included in the study. At the time of diagnosis, sFLC values were requested simultaneously with bone marrow biopsy. Radiological images were obtained with PET CT/MRI or CT.
 Results: In all MM groups, bone marrow PH percentages were not correlated with sFLC regardless of subtype. IgG kappa type MM had the highest sFLC values despite the lowest number of PHs, while Lambda light chain MM had the lowest sFLC despite the highest PH rates. 
 Conclusion: These results showed us that sFLC rates are independent of the percentage of PC in MM. We believe that the two are not correlated and should be followed up together in the follow-up of the disease.

Prognostic Significance of Monoclonal Paraproteinemia in Marginal Zone Lymphoma

Introduction and aim:Marginal zone lymphoma (MZL) is an indolent lymphoma which can progress with frequent relapses and transform to aggressive lymphoma. Therefore, the factors that affect prognosis are important fields of interest. This study was aimed to investigate the effect of immunoglobulin (Ig) paraproteinemia on MZL prognosis and survival. Material and method: Between January 2000 and June 2022, 73 patients who applied to Dokuz Eylül University Faculty of Medicine Hospital Department of Hematology, diagnosed with MZL, and continued their follow-up in our center were assessed. Patients whose paraproteinemia was investigated by immunofixation (SIFE), serum protein electrophoresis (SPEP), or free kappa and lambda free light chain (FLC) assays were included in the study. Demographic characteristics and laboratory data were retrospectively analyzed. Results: Ig paraproteinemia was ascertained in 20 patients which 11 of 20 was IgM type. The median follow-up was 58 (3-200) months. Median overall survival (OS) and progression free survival (PFS) were not reached. Mean OS and PFS were 169±8.5 and 146±10.6 months, respectively. Serum Ig paraproteinemia was detected in 20 of 73 patients (27.3%). Most were IgM- κ (9, 45%), followed by IgG-κ (7, %35), IgM-λ (2, %10), IgA-λ (1, %5), and IgA-κ (1, %5). The presence of Ig paraproteinaemia was significantly associated with advanced age (p<0.001), advanced disease stage (III-IV) (p=0.023), elevated ß2 microglobulin (ß2MG) level (p=0.001), decreased hemoglobin level (p=0.002), decreased albumin level (p<0.001), and bone marrow involvement (p=.026). Gender, elevated lactate dehydrogenase (LDH) level, and elevated Ki-67 were not significantly associated with the presence of Ig paraproteinaemia. In our cohort Ig paraproteinemia was shown in 35%, 10% and 55% of extranodal MZL, splenic MZL and nodal MZL respectively (p=0,009) which favors nodal MZL dominance. The prognostic value of Ig paraproteinaemia and other clinical outcomes are summarized in Table 1. The OS rate at 5 and 10 years was %87.2 and %81.9, respectively. The PFS rate at 5 and 10 years was %71.5 and %68.3 respectively. Patients with Ig paraproteinaemia has shorter OS compared to patients without any paraproteinemia (73,8 mo. vs 178,8 mo. p<0,05). This survival disadvantage was more pronounced in patients with IgM paraproteinemias. Kaplan-Meier survival curve analysis of PFS according to the occurrence of Ig paraproteinaemia are shown in Figure 1. Conclusion: Although MZL is an indolent lymphoma type and there are many prognostic factors affecting its prognosis, it may show relapsed or refractory disease course or histological transformation. 55% of our nodal MZL cohort had Ig paraproteinemia which is higher than all reported cohorts in the literature so far. Several studies have previously shown that Ig paraproteinemia may be a potential prognostic factor for NHL and MALT lymphoma 1-3. Ren et al. showed that Ig paraproteinemia was an independent prognostic predictor for MALT lymphoma 4. Epperla et al. showed that patients diagnosed with MZL with Ig paraproteinemia had inferior survival in comparation with no-M protein group 5. In conclusion, this study provides evidence that Ig paraproteinaemia and especially of IgM type shortens PFS and OS in patients with MZL. Thus, our study is the first in literature to show survival disadvantage for MZL patients specifically with IgM paraproteinemia and deserves confirmation with further studies.

Characteristics and Outcomes of Adolescent, Young Adults, and Adults 40-50 Years Old with Multiple Myeloma: A Single Center Experience

Background Multiple myeloma (MM) is a malignant tumor with abnormal proliferation of plasma cells. Adolescent and Young Adult (AYA) patients are defined as patients between 15-39 years of age. Multiple myeloma is uncommon in non-elderly populations. Its prevalence is only 2% in AYA age group and only 10% in patients 40-50 years old. The feature of MM is not well known or understood in those two age groups. In this retrospective study we describe the clinical characteristics, cytogenetics, prognostic markers, treatments given and outcomes of MM in AYA and 40-50 years old patients. Methods We retrospectively analyzed data from the clinical database of our single tertiary hematology center, The National Center for Cancer Care and Research, Doha, Qatar. This center serves a country's population of about 2,8 million people. All patients diagnosed with MM between the age 50 or less during the period of January 2007 to December 2022 were included. Results Seventy-four patients were diagnosed at our centre with MM before the age of 50 years, total of all MM cases 222 (33%) Males was predominant 55/74 (74.3 %) with a median age of 41 years (range, 15-49). Most of the patients were from Asian 55%. At diagnosis patients had a median hemoglobin of 10.2 g/dl, creatinine 294 umol/L, total protein 90 gm/L, albumin 34.75 gm/L, calcium 2.7 mmol/L, LDH 255 U/L, IgG 2289.75 mg/dl, IgA 424.15 mg/dl, IgM 34.2 mg/dl, FLC-Kappa 1993 mg/L and FLC-Lambda 1177 mg/L. Median of bone marrow filtration by plasma cell was 51 %. Most of the patients presented at advance stages with 44 patient (59%) presented as IIIA Durie Salmon or stage III and IV by ISS 70 %. IgG Kappa most frequent type of MM 18 patients (24%), followed by Free light chain kappa (23%), IgG Lambda (18%) and others including two cases of plasmacytoma (Most recurrent cytogenetics were diploid cytogenetics in 42 patients (57%), while 7 patients (9%) had complex cytogenetics. Twenty-eight patients had spinal cord compression at single or multiple levels ( thoracic were most common site 20%) while 3 patients had pathological fractures. Bortezomib based regimen is most one used to treat our patients. Daratumumab- Velcade, Revlimid, and dexamethasone (D-VRD) was used for 35 patients (74%) and Velcade,Cyclophosphamide and Dexamethasone VCD in 20 patients (27%). The first response to treatment showed completed remission (CR) in 35 patients, very good partial remission in 10 patients, partial response in 9 patients, four patients either refractory or primary refractory disease and one patient with stable disease. Thirty -five patients (48%) underwent their first autologous bone marrow transplant ASCT. A total of 8 patients underwent second ASCT and one patient underwent third ASCT. After a median duration of follow up of 6.25 years and 72 % of the patients were still alive. We compared the characteristics and outcome for the AYA group (18-39) with patient age group 40 to 49 years. Although there was no statistical significance difference between the two groups regarding overall survival (p=0.21) , the older group had more cases of spinal cord compressions and more cases of refractory disease. Patient characteristics are described in Table 1. Conclusion One third of MM patients in our center are younger than 50 years. These patients tend to present with advanced stage and serious manifestation such as spinal cord compression. IgG kappa and free light chain are the most common myeloma type in this cohort. D-VRD is the most used protocol with a good response rate. Patient characteristics and treatment outcomes are the same for AYA patients compared with patients 40-49 years old (p=0.21). Patients who received first transplant had better OS compare the those who didn't (p0.01)

Clonal Bone Marrow Plasma Cells Are Common in Patients with Vexas Syndrome

Introduction Monoclonal gammopathy of undetermined significance (MGUS) is a premalignant plasma cell disorder. Its prevalence increases with age, reaching 5.3% at 70 years and older. MGUS progression rate to multiple myeloma (MM) or lymphoplasmacytic malignancies is about 1% per year. Patients with autoimmune diseases are at increased risk for developing MGUS and MM. VEXAS ( vacuoles, E1 enzyme, X-linked, autoinflammatory and somatic syndrome), an autoinflammatory disorder caused by somatic mutations in ubiquitin-activating enzyme, UBA1 gene, has been associated with plasma cell disorders, specifically MGUS, but the rate of progression is unknown. Cyclin D1, important in cell cycle progression, is regulated by ubiquitin-proteasome mediated degradation, and deregulated cyclin D1 degradation appears to be responsible for the increased levels of cyclin D1 in several cancers. We aim to assess marrow characteristics of plasma cell disorders (MGUS and MM) in VEXAS, and the impact of a defective UBA1 gene product on protein expression of cyclin D1. Methods We assessed 28 patients with VEXAS for the presence of plasma cell disorders, and studied the clinical and laboratory characteristics of those with clonal plasma cells (PC) in the marrow. Bone marrow biopsies and aspirates were evaluated by morphology, immunohistochemistry (IHC) dual staining CD138/cyclin D1, dual staining MUM-1/CD20), in situ hybridization (Kappa and Lambda light chains) and flow cytometry (FC) using antibodies for CD45, CD19, CD20, CD38, CD138, CD56, CD27, CD81, and cytoplasmic Kappa and Lambda immunoglobulins. Serum free kappa and lambda light chains, IgG, IgM, and IgA, and level of M paraprotein by serum protein electrophoresis with immunofixation were obtained. Fluorescent in situ hybridization (FISH) analysis for MM was performed in most patients with clonal PCs. Results Patients' characteristics are shown in Table 1. Eight out of 28 (28.6%) patients with VEXAS syndrome, all males, had clonal plasma cells in their bone marrows: 3 MGUS, and 5 MM (3 smoldering, SMM; 2 active MM). Median age at diagnosis of plasma cell disorder was 69.5 years (range 60-75). All patients had pathogenic UBA1 somatic mutations (5 M41T, 1 each with M41V, M41L, and splice). Clinically, monoclonal protein size was small, with no specific selection of the type of M protein. Strikingly, most (7/8) clonal plasma cells showed cyclin D1 expression by IHC (dual immunohistochemical stain cyclinD1/CD138 shows double-positive plasma cells; figure not shown), displaying nuclear immunoreactivity in 6 cases, and cytoplasmic immunoreactivity in 1 case. FC showed positive CD20 expression of clonal plasma cells in 4 cases, dim to negative CD19 expression in 4 cases, variable CD56 (positive in 3 cases, partial positive in 1 case, negative in 2 cases), dim to negative CD27 in 3 cases, dim to negative CD81 in 3 cases. FISH for MM revealed: t(11;14) in 4 cases, gain of 11q (CCND1) in 2 cases (in one case, CCND1 gain was present in addition to t(11;14); in the second case, CCND1 gain was associated with gains of 1q and 17p(TP53). The cyclin D1-negative MM case was negative for t(11;14) but had t(4;14). All cases with t(11;14) were positive for cyclin D1 by IHC (nuclear staining). The one MM case with negative nuclear staining for cyclin D1 but positive cytoplasmic staining, was negative for t(11;14) but had gain of 11q (CCND1).One patient evolved from SMM to active MM after 4 years. No evolution to MM was seen in patients with MGUS with median follow-up of 30 months. Conclusions Patients with VEXAS have a high prevalence of clonal plasma cell disorders. Clonal plasma cells in VEXAS patients are associated with t(11;14), and with nuclear cyclin D1 expression by IHC. Cytoplasmic cyclin D1 staining in the absence or weak nuclear staining was observed with CCND1 gain and absence of t(11;14). Cytoplasmic cyclin D1 expression may be related to lack of cyclin D1 protein degradation by a defective UBA1 gene product. Our results suggest that defective UBA1 and autoinflammation pose an increased risk for developing MGUS or multiple myeloma.

Revised Definition of Free Light Chains in Serum and Light Chain Monoclonal Gammopathy of Undetermined Significance: Results of the Istopmm Study

Background: Serum free light chain (FLC) measurement, consisting of serum free kappa, serum free lambda, and a calculated FLC ratio (kappa/lambda), plays a pivotal role in the diagnosis, risk stratification and management of plasma cell disorders. Light chain monoclonal gammopathy of undetermined significance (LC-MGUS), is defined as abnormal FLC ratio with elevation of the involved FLC without evidence of heavy chain M protein or end-organ damage attributed to the plasma cell disorder. Several years ago, reference intervals for serum kappa (3.3-19.4 mg/L) and lambda (5.7-26.3 mg/L) FLC and FLC ratio (0.26-1.65) were defined in a small retrospective cohort (N = 282) of healthy individuals. Limitation of these reference intervals include inaccurate distributions among individuals with impaired kidney function. Recently, we addressed this matter in a large population-based study focusing on individuals with estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73m 2, the results of which led to redefined reference intervals for patients with chronic kidney disease (Long et al, Blood Cancer J. 2022). Here, using a large cohort (N=41,882) of screened individuals, we aimed to determine FLC reference intervals in individuals with normal kidney function (eGFR ≥ 60 mL/min/1.73m 2). Methods: Data were collected from the ongoing Iceland Screens, Treats, or Prevents Multiple Myeloma (iStopMM) study, which focuses on population-based screening for MGUS. A total of 75,422 individuals aged ≥ 40 years (representing 51% of this age group in the Icelandic population) were screened for MGUS by serum protein electrophoresis, immunofixation, and serum FLC assay (Freelite®), and two-thirds of MGUS cases were randomized to active follow-up. Participants' eGFR was calculated using serum creatinine (CKD-EPI) closest to the time of screening. Participants with heavy chain M protein, known lymphoproliferative disorder, unknown eGFR or eGFR < 60 mL/min/1.73m 2, were excluded. The 0.5 and 99.5 percentiles of kappa FLC, lambda FLC, and the FLC ratio distributions were assessed for the whole group, and subgroups of age, sex, and different levels of eGFR. A nonparametric bootstrapping method was used to calculate the 95% confidence intervals. Partitioning was determined based on the proportion of subgroups (age, sex and eGFR) outside the whole group reference interval. Results: After application of the exclusion criteria, 41,882 participants were included for further analysis. The median (interquartile range, IQR) serum free kappa was 14.3 (11.6-17.8) mg/L, serum free lambda 14.2 (11.6-17.5) mg/L, and the FLC ratio was 1.02 (0.85-1.21). The median (IQR) age was 60 (52-68) years, eGFR 84 (74-94) mL/min/1.73 m 2, and 43% were male. A strong correlation was found between age and serum kappa FLC (ρ = 0.27, p < 0.001), lambda FLC (ρ = 0.14, p < 0.001), and the FLC ratio (ρ = 0.16, p < 0.001). Use of standard reference intervals yielded abnormal results for 17.5%, 3.9%, and 4.5% of serum kappa, lambda, and FLC ratio determinations, respectively, and a prevalence of LC-MGUS of 2.0% (96% kappa and 4% lambda). Based on these findings, we established new reference intervals for serum kappa and lambda FLC and FLC ratio, partitioned by age < 70 years and ≥ 70 years (Table). Utilizing the new reference intervals the crude prevalence of LC-MGUS was 0.3% (54% kappa and 46% lambda), yielding a relative decrease of 83%. Among the group of individuals diagnosed with LC-MGUS based on standard reference intervals who did not meet the diagnostic criteria using our revised reference intervals - none had progressed to a lymphoproliferative disorder after a median follow-up time of 42 months. Conclusion: Based on prospective screening of more than 40,000 individuals and after 3.5 years of follow-up, we show that standard reference intervals for serum FLC and FLC ratio appear inaccurate for persons with preserved kidney function. We propose a revision of the reference intervals for serum FLC and FLC ratio, and a new definition of LC MGUS (Figure). Implementation of new reference intervals will decrease the rate of false positive diagnosis of LC-MGUS in individuals with preserved kidney function by more than 80%. This, in turn, will reduce the unnecessary psychological and financial burden driven by clinical evaluation and lifelong monitoring of these individuals.

The role of intrathecal free light chains kappa for the detection of autoimmune encephalitis in subacute onset neuropsychiatric syndromes

Intrathecal synthesis of free light chains kappa (FLCK) is increasingly recognized as a marker of inflammatory CNS pathologies. Here, we tested the performance of FLCK in differentiating autoimmune encephalitis (AIE) from non-inflammatory etiologies in subacute onset neuropsychiatric syndromes. Patients undergoing diagnostic work-up for suspected autoimmune encephalitis at our department between 2015 and 2020 were retrospectively assessed for definitive diagnosis, available CSF and blood samples, as well as complete clinical records. Intrathecal FLCK was measured along with established CSF markers of CNS inflammation. The study cohort consisted of 19 patients with antibody-mediated AIE (AIE+), 18 patients with suspected AIE but without detectable autoantibodies (AIE–), 10 patients with infectious (viral) encephalitis (INE), and 15 patients with degenerative encephalopathies (DGE). 25 age- and sex-matched patients with non-inflammatory neurological diseases (NIND) were used as a control group. All AIE+ patients exhibited intrathecal synthesis of FLCK compared to only 39% of AIE– patients and 81% of patients in the INE group. No intrathecal synthesis of FLCK was found in DGE and NIND patients. While intrathecal FLCK was equally specific for an inflammatory etiology as oligoclonal bands (OCB) in the cerebrospinal fluid (CSF), the sensitivity of intrathecal FLCK for any inflammatory intrathecal process was higher than that of OCB (83% vs. 38%). Intrathecal FLCK synthesis was found to discriminate AIE+ from non-inflammatory encephalopathies and AIE– when the CSF cell count was normal [receiver operating characteristic (ROC) analysis area under the curve (AUC): 0.867, p = 0.002], while it failed to differentiate between AIE+ and INE in the presence of CSF pleocytosis (AUC: 0.561, p = 0.607). In conclusion, in the absence of CSF pleocytosis, intrathecal FLCK discriminated AIE+ from competing diagnoses in our cohort of subacute onset neuropsychiatric syndromes. In addition to established markers of CSF inflammation, intrathecal FLCK might support clinical decision-making and contribute to selecting patients for (repeated) antibody testing.

SAT210 A Case Of Recurrent Metastatic Parathyroid Cancer Complicated By Multiple Brown Tumors

Abstract Disclosure: A. Elmaaz: None. E. Bustamante: None. M. Batra: None. Introduction: Parathyroid cancer is a rare malignancy with about 25 % incidence of metastasis. Brown tumors are benign bone lesions caused by excessive bone turnover which are rarely associated with parathyroid carcinoma. Here, we present a case of recurrent metastatic parathyroid cancer complicated by multiple brown tumors. Case Presentation: A 63-year-old male presented with back pain, generalized weakness, and significant weight loss. Laboratory findings showed hypercalcemia 14.4 mg/dl, Alkaline phosphatase 253 U/L, and phosphorus 2.3 mg/dl. He was admitted to the hospital for hypercalcemia workup. MRI spine showed a heterogeneous mass arising from the left thyroid lobe and conglomerate lymph node, along with extensive metastatic sclerotic lytic lesions throughout the spine. MRI brain revealed multiple metastatic lesions in the skull base, facial bones, and the right angle of the mandible. Further workup revealed normal PSA, normal serum levels of free lambda and kappa light chains, and normal urine and serum protein electrophoresis. PTH levels, 2435.1 (8.7-77.1) pg/ml, and PTH-rP levels <1.1 pmol/l were noted. Ultrasound-guided FNA of the thyroid mass showed solid growth of malignant parathyroid cells strongly stained for PTH. Biopsy of the body of the T12 vertebra and mandibular lesions showed giant cell lesions of the bone with fibrous dysplasia, consistent with brown tumors. IV hydration, calcitonin, cinacalcet, and IV zoledronic acid started, followed by left hemithyroidectomy and left inferior parathyroidectomy. Surgical pathology was positive for parathyroid carcinoma invading the thyroid gland. His calcium and PTH levels post-surgery significantly improved. A few months later, the patient presented again with hypercalcemia and high levels of PTH. Sestamibi parathyroid scan showed no evidence of parathyroid adenoma. Because of enlarging left neck mass, confirmed by MRI neck, he then underwent excision of the left subcutaneous cervical lesion involving the left sternomastoid muscle. Surgical pathology was consistent with parathyroid carcinoma involving soft tissue. His calcium and PTH levels improved on subsequent follow-up visits. Conclusion: Parathyroid carcinoma is not a common cause of hypercalcemia. Though a rare entity, parathyroid cancer should be considered in the differentials of hypercalcemia and extremely high levels of PTH. Metastasis either locally or remotely should not be overlooked. Brown tumors could mimic bone metastasis and giant cell tumors; therefore, the clinical presentation is important for the diagnosis. Presentation: Saturday, June 17, 2023

Beyond SEP-1 Compliance: Assessing the Impact of Antibiotic Overtreatment and Fluid Overload in Suspected Septic Patients

BackgroundThe Centers for Medicare and Medicaid Services (CMS) developed the Severe Sepsis and Septic Shock Performance Measure bundle (SEP-1) metric to improve sepsis care, but evidence supporting this bundle is limited and harms secondary to compliance have not been investigated. ObjectiveThis study investigates the effect of an emergency department (ED) sepsis quality-improvement (QI) effort to improve CMS SEP-1 compliance, looking specifically at antibiotic overtreatment and harm from fluid resuscitation. MethodsThis was a retrospective observational study conducted between March and July 2021 with patients for whom a sepsis order set was initiated. The primary outcomes included the number of patients treated with antibiotics who were ultimately deemed nonseptic and the number of patients who developed pulmonary edema, with or without need for positive pressure ventilation (PPV), within 48 h of receiving a 30 mL/kg fluid bolus. Data were collected via nonblinded chart reviews, with a free marginal κ-calculation indicating excellent interrater reliability. ResultsThe study cohort included 273 patients, 170 (62.3%) who were ultimately determined to be septic and 103 (37.7%) who were nonseptic. Of the 103 nonseptic patients, 82 (79.6%) received antibiotics in the ED. Of the 121 patients (44.3%) who received a 30 mL/kg bolus, 5 patients (4.1%) developed pulmonary edema and 0 of 121 patients required PPV within 48 h. ConclusionsThe QI effort led to moderate rates of antibiotic overtreatment and very few patients developed pulmonary edema due to a 30 mL/kg fluid bolus.

Improving the efficiency of free kappa light chains as diagnostic biomarker of Multiple Sclerosis by using a novel algorithm

BackgroundIntrathecal immunoglobulin synthesis (ITS) plays a crucial role in the diagnosis of multiple sclerosis (MS). Traditionally, the gold standard method for detecting ITS has been through the analysis of oligoclonal bands (OCB). However, the paradigm has shifted with the introduction of the free kappa light chains (FKLC) method. In fact, a recent consensus recommends evaluating FKLC index (FKLCi) as the primary approach and reserving oligoclonal bands with borderline results. The objective of our study is to investigate the diagnostic efficiency of combining FKLC with other methods to predict ITS while minimizing the reliance on OCB. MethodsA total of 192 patients were included in the study, consisting of 145 individuals diagnosed with multiple sclerosis (pwMS) and 46 with other neurological diseases (controls). Among the MS cases, 100 patients were assigned to the Training Cohort (TC), while an external Validation Cohort (VC) comprised of 45 MS patients was established. Diagnostic efficiency was assessed for FKLCi, OCB, Link index, and the Reiber formula for IgG and FKLC. Optimal cutoff values for Link index and FKLCi were also determined. The last procedure was developed for diverse algorithms using the parameters mentioned above, which included the optimal cutoffs previously obtained. The calculations were conducted independently for both the TC and the VC, as well as for a composite cohort formed by combining data from all patients (OC) ResultsOne algorithm, named KRO, was developed based on the determination of FKLCi and Reiber Formula as the primary diagnostic parameters. For cases where the FKLCi result was mildly increased, OCB was utilized as a supplementary test. The KRO algorithm demonstrated superior diagnostic accuracy in the OC (89%), resulting in a reduction of OCB consumption by 91%. DiscussionThe KRO algorithm demonstrated superior sensitivity and accuracy although lower specificity and NPV compared to the use of FKLCi and OCB alone. The present research aligns with the new consensus recommendations regarding the diagnostic approach. Our findings indicate that employing a combined marker approach via KRO could prove to be a proficient screening tool for multiple sclerosis. This approach also holds the potential to address inherent limitations associated with each individual marker. However, to further validate and solidify the efficacy of our algorithm, additional studies involving larger cohorts are warranted.