IgG Lambda Research Articles

An Occult Malignancy Behind a Demyelinating Disease: POEMS Syndrome.

We report a case of a 38-year-old man presenting with bilateral lower extremity weakness and paresthesias that progressed during a 4-month period to severe polyneuropathy forcing the patient to be bed bound. Throughout his multiple hospitalizations, he was treated erroneously for chronic inflammatory demyelinating polyneuropathy, without significant improvement in his symptoms. In addition, he developed hepatosplenomegaly (organomegaly); endocrinopathies such as diabetes mellitus, central hypogonadism, and hypothyroidism; monoclonal spike evidenced in the serum electrophoresis; and hyperpigmentation of skin, altogether consistent with POEMS syndrome. During his last hospitalization he developed excruciating pain on his left hip, and imaging revealed the presence of a 9 × 6 cm osteolytic mass with sclerotic rim in the left acetabulum. Biopsy of the mass confirmed an isolated IgG lambda plasmacytoma. The patient received radiation to his left acetabular lesion followed by left hip replacement. Subsequently, the patient underwent autologous bone marrow transplant. Eighteen months after his initial presentation, he had satisfactory clinical response and is functional without significant limitations. POEMS syndrome is a rare paraneoplastic syndrome secondary to an underlying plasma cell disorder, which can oftentimes be overlooked and misdiagnosed. The median age of presentation is 51 years, and only 31% of the cases occur in fairly young patients under the age of 45 as evidenced in this case. As clinicians, we should be aware of the constellation of features associated with POEMS syndrome and be able to recognize them promptly.

Quantitation of IgG kappa and IgG lambda in the cerebrospinal fluid by sandwich ELISA method

IgG kappa and IgG lambda concentrations were quantified in 96 paired CSF and sera using Hevylite™ antibodies in an in-house developed sandwich ELISA method. In 56 of these samples, the results were compared with a qualitative isoelectric focusing/affinity-mediated immunoblotting assay for oligoclonal IgG kappa and IgG lambda. Normal IgG kappa/lambda ratio in the CSF was the same as in serum. In 19/33 patients with intrathecal oligoclonal IgG synthesis, skewed IgG kappa/lambda ratio was observed (increased in 16 and decreased in 3 cases). The analysis of light chain composition of intrathecally synthesised immunoglobulins could contribute to our understanding of intrathecal humoral immune response, although its diagnostic utility is limited.

P.412 - Diagnostic implications of three cases of skeletal muscle light-chain (AL) amyloidosis

A 70-year-old female with a two year history of painless, progressive proximal weakness and markedly elevated CK (>1600 U/l), a 74-year-old male with a year's history of exercise-induced myalgia, including claudicatio masticatoria and fatigue with CK in the normal range and a 79-year-old male with a four month history of myalgia, constipation and weight loss with elevated CK were diagnosed with skeletal muscle amyloidosis by Congo red stain on muscle biopsy samples. They had IgG lambda, IgA lambda and IgG kappa light chain paraproteins, respectively. In the first and third case, sural nerve biopsies showed some, predominately axonal damage, but no amyloidosis. Rectum biopsy in the second as well as colon and gastral biopsy in the third case failed to detected amyloid deposition, too. In case one, the diagnosis of °I plasmocytoma and in case three of suspected multiple myeloma had been established, but prior to the diagnosis of amyloidosis, no treatment was considered necessary. In the second case, the paraprotein was discovered at the time of biopsy. In every case, muscle biopsy showed some aspects of neurogenic damage and nerve conduction studies revealed some abnormalities. In case one, deposition of congophilic, birefringent material was solely vascular, while in case two and three there was some deposition surrounding muscle fibres. In case three only, immunohistochemistry showed activated complement (C5b9) colocalised with amyloid deposition, widespread capillary changes and perimysial pathology. All the clinical and biopsy findings in these cases are in line with the literature. Nerve, rectum and possibly labial salivary gland biopsies are generally considered to have a higher detection rate for amyloidosis. However, we conclude that biopsy analysis of clinically affected muscle should be the standard procedure in patients with muscular complains and paraprotein. A non-conclusive biopsy of another tissue cannot be accepted as a substitute.

IgV peptide mapping of native Ro60 autoantibody proteomes in primary Sjögren's syndrome reveals molecular markers of Ro/La diversification

We have used high-resolution mass spectrometry to sequence precipitating anti-Ro60 proteomes from sera of patients with primary Sjögren's syndrome and compare immunoglobulin variable-region (IgV) peptide signatures in Ro/La autoantibody subsets. Anti-Ro60 were purified by elution from native Ro60-coated ELISA plates and subjected to combined de novo amino acid sequencing and database matching. Monospecific anti-Ro60 Igs comprised dominant public and minor private sets of IgG1 kappa and lambda restricted heavy and light chains. Specific IgV amino acid substitutions stratified anti-Ro60 from anti-Ro60/La responses, providing a molecular fingerprint of Ro60/La determinant spreading and suggesting that different forms of Ro60 antigen drive these responses. Sequencing of linked anti-Ro52 proteomes from individual patients and comparison with their anti-Ro60 partners revealed sharing of a dominant IGHV3–23/IGKV3–20 paired clonotype but with divergent IgV mutational signatures. In summary, anti-Ro60 IgV peptide mapping provides insights into Ro/La autoantibody diversification and reveals serum-based molecular markers of humoral Ro60 autoimmunity.

Clinicopathological significance of monoclonal IgA deposition in patients with IgA nephropathy.

Clinicopathological significance of monoclonal IgA deposition and its relation to bone marrow abnormalities in IgA nephropathy (IgAN) remains unclear. We retrospectively investigated the prevalence and clinicopathological significance of monoclonal IgA deposition in 65 patients with IgAN. Serum-free light chain ratio, and urinary Bence Jones protein were also measured. Thirty-nine percent of patients were men, median age was 40 and median observation period was 31months. Five patients (Group M) showed monoclonal IgA lambda deposition and one showed monoclonal IgA kappa deposition. Fifty-nine patients (Group P) showed polyclonal IgA deposition. There were no significant differences in the degree of proteinuria, hematuria and renal function between Group M and Group P. Total protein and albumin were significantly lower in Group M than in Group P. According to the Oxford classification, the percentage of patients with M1 was significantly higher in Group M than in Group P. One patient in Group P showed serum monoclonal IgG lambda. No patient showed abnormal serum-free light chain ratio. Seventy-five percent in Group M and 42% in Group P were treated with steroid. Three patients in Group P progressed to end-stage renal disease (ESRD). The frequency of disappearance of proteinuria or hematuria and progression to ESRD was not different between the groups. The prevalence of monoclonal IgA deposition was 9.2%. Although some parameters differed between the groups, renal outcome were similar. Thus, IgAN with monoclonal IgA deposition seems not to be different entity from those with polyclonal IgA deposition.

Scleromyxedema (Arndt-Gottron Syndrome): a Case Report

Abstract Lichen myxedematosus, also known as papular mucinosis, is a primary diffuse cutaneous mucinosis. It is a rare cutaneous myxedematous condition characterized by formation of numerous lichenoid papules. Scleromyxedema, also known as Arndt–Gottron syndrome, is a rare, confluent, papular and sclerotic variant of lichen myxedematosus, characterized by diffuse thickening of the skin underlying the papules. The condition is associated with systemic, even lethal manifestations, fibroblast proliferation and accumulation of acid mucopolysaccharides of the hyaluronic acid. Serum IgG class paraproteinemia is always present and it can be detected in all patients if appropriate or even repeat testing is used. Herein, we present a 67-year-old patient with a 2-year history of skin problems. He had no health problems other than hypertension and diabetes, wich were both diagnosed 15 years before. On examination, the patient exhibited sclerodermoid lesions with diffuse pseudo-sclerodermatous thickening of the exposed skin, microstomia and sclerodactyly-like changes; on the face, there were numerous solid, shiny 2 - 4 mm in diameter skin-coloured lichenoid papules, scattered across the forehead, glabellar area, nasolabial folds, perioral region, ear lobes and the neck. Histopathological examination revealed: highly distinctive collagenosis and fibrosis in the middle dermis, increased fibroblasts; collagen bundles with irregular arrangement and fragmentation; alcian blue-positive deposits with appearance consistent with acid mucins. Serum protein electrophoresis detected IgG lambda paraproteinemia. The patient was treated with systematic corticosteroids during 9 months with subsequent introduction of methotrexate and showed satisfactory results. The etiology of scleromyxedema remains unknown, since the purified IgG paraprotein itself has no direct effects on fibroblast proliferation. In scleromyxedema, numerous therapeutic modalities are proposed, unfortunatelly with limited effects. In colclusion, we report a case of an adult male with lichenoid papules; after a two-year progression, they evolved into scleromyxedema and exhibited well response to conventional therapy.

The Immunotyping Distribution of Serum Monoclonal Paraprotein and Environmental Impact on Multiple Myeloma (MM) and Monoclonal Gammopathy of Uncertain Significance (MGUS) in Taiwan: A Medical Center-Based Experience.

Whether ambient exposure to environmental pollutants leads to hematopoietic malignancies such as multiple myeloma (MM) remains to be ascertained. Therefore, we aimed to investigate the immunotyping distribution of serum monoclonal paraprotein and the environmental influence on MM and monoclonal gammopathy of uncertain significance (MGUS) in the Taiwanese population. Serum protein electrophoresis with immunosubtraction by the capillary zone electrophoresis method was performed as primary screening for MM and MGUS. Clinical, pathological, and residence data of patients were also obtained. From August, 2013 to June, 2015, a total of 327 patients underwent serum protein electrophoresis with immunosubtraction. Among these, 281 demonstrated no remarkable findings or non-malignant oligoclonal gammopathy, 23 were detected to have MGUS, 18 were identified as MM, and a further 5 were found as other malignancies. The most frequent immunotyping distribution of serum monoclonal paraprotein was IgG kappa (54.3%, n=25), followed by IgA lambda (15.2%, n=7) and IgG lambda (10.9%, n=5) in subjects with gammopathy. Additionally, it was shown that the elderly (OR: 4.61, 95% CI: 1.88-11.30, P<0.01) and males (OR: 2.04, 95% CI: 1.04-4.02, P=0.04) had significantly higher risk of developing MM and MGUS. There was no obvious impact of environmental factors on the health risk of MM and MGUS evolution (OR: 0.77, 95% CI: 0.40-1.50, P=0.49). The most frequent immunotyping distribution of serum monoclonal paraprotein included IgG kappa, IgA lambda and IgG lambda in MM and MGUS in the Taiwanese population. The elderly and male subjects are at significantly higher risk of MM and MGUS development, but there was no obvious impact of environmental factors on risk.

The Role of Serum Free Light Chain and M-Protein Measurements in Determining Recurrent Disease in Multiple Myeloma After Stem Cell Transplantation

The detection of reoccurrence of multiple myeloma (MM) after stem cell transplant (SCT) is usually carried out by the use of serum and urine protein electrophoresis and immunofixation. We retrospectively studied the utility of serum free light chain assay (sFLC) in a population of post-SCT MM patients and compared it to traditional methods with serum protein electrophroesis (SPEP). We compared the value of sFLC vs SPEP for predicting reoccurrence and for earlier detection. We analyzed consecutive 24MM patients diagnosed between 2004 and 2009, who underwent SCT with concomitant follow-up with sFLC and M-protein from 2004 to 2012. An elevated M-protein was indicated by a level ?0.2g/dL. An abnormal sFLC was indicated by a ?:? ratio >1.65 or 10 mg/dL of sFLC from the baseline. Of the 24 cases, 22 had intact immunoglobulin MM (16 IgG, kappa; 2 IgG lambda; 2 IgA lambda; 2 IgA kappa) and 2 cases had light chain MM. All 24 cases (100%) achieved a complete response or partial response to SCT as defined by the International Myeloma Working Group (IMWG). After SCT, 4 (16.7%) MM patients remained in remission. 12 (50.0%) patients had a recurrence of MM with measurable increases in both sFLC and M-spike, 5 (20.8%) with increase in sFLC only and 3 (12.5%) with increase in M-spike alone. Among the 20 patients with reoccurrence after SCT, 35% had earlier detection of sFLC than M-spike, 10% had M-spike detected before sFLC, 15% had concurrent elevated sFLC and M-spike, 25% had elevated sFLC only, and 15% had elevated M-spike alone. The medium time period for detecting the elevated sFLC or M-spike in patients undergoing reoccurrence after SCT was 3-6 months vs. 6-9 months (p-value: 0.0386; Mann-Whitney one-sided test). Our study concludes that sFLC should be used in conjunction with clinical and other traditional measures for the earliest detection of MM recurrence to ensure that the diagnosis is not missed by using SPEP assay alone.

Renal Thrombotic Microangiopathy Associated with the Use of Bortezomib in a Patient with Multiple Myeloma.

Bortezomib is a first-generation proteasome inhibitor used in the treatment of multiple myeloma (MM). A few reports have linked bortezomib exposure with the development of thrombotic microangiopathy (TMA). We describe a case of biopsy-proven renal thrombotic microangiopathy associated with the use of bortezomib in a 51-year-old man with IgG lambda MM. To our knowledge, this is the first biopsy-proven case. In addition, reexposure to bortezomib 18 months later was associated with recurrence of TMA. This supports a possible causal role of bortezomib. The exact mechanisms remain to be elucidated.

Alpha 3 ganglionic acetylcholine receptor antibody associated refractory status epilepticus

Autoimmune encephalitides are a group of syndromes that may present with subacute onset of disorientation, personality changes, memory loss and most prominently seizures. Earlier reports of this entity were from patients with paraneoplastic limbic encephalitis, however autoimmune etiologies have also been described in patients with non-paraneoplastic encephalitis [1]. The Alpha 3 ganglionic acetylcholine receptor autoantibody (a3-AChR Ab) mainly causes autoimmune dysautonomia that is either subacute or insidious in onset. A direct relationship betweenantibody titer and severity of dysautonomia occurs in both experimental animals and patients [2]. Most of these cases have been paraneoplastic (mainly adenocarcinomas) however a few cases have been linked to other autoimmune disorders such as systemic lupus erythematosus (SLE) and Sjogren’s syndrome. Patients who are seropositive for a3-AChR Ab may present with less common neurological manifestations such as peripheral neuropathies, encephalopathy and subacute neuropsychiatric presentations. This report presents a unique case of refractory new-onset status epilepticus associated with a3-AChR antibody which responded to immunotherapy.

Remissions of Multiple Myeloma during a First-in-Humans Clinical Trial of T Cells Expressing an Anti-B-Cell Maturation Antigen Chimeric Antigen Receptor

B-cell maturation antigen (BCMA) is a protein expressed by normal and malignant plasma cells. We are conducting a phase I clinical trial of an anti-BCMA chimeric antigen receptor (CAR-BCMA) that incorporates an anti-BCMA single-chain variable fragment, a CD28 domain, and a CD3-zeta T-cell activation domain (Carpenter et al. Clinical Cancer Research 2013). Autologous T cells are genetically modified to express the CAR with a gamma-retroviral vector. Patients receive a single infusion of CAR-BCMA T cells. Before the CAR T-cell infusions, patients receive a chemotherapy regimen of 300 mg/m2 of cyclophosphamide and 30 mg/m2 of fludarabine with each chemotherapy agent given daily for 3 days. The purpose of the chemotherapy is to enhance activity of the CAR T cells by depleting endogenous leukocytes. Twelve patients have been enrolled, and 11 patients have been treated on one of 4 dose levels, 0.3x106, 1x106, 3x106, and 9x106CAR+ T cells/kg of bodyweight. Patients had advanced multiple myeloma (MM) with a median of 7 prior lines of therapy.Of the 6 patients treated on the lowest 2 dose levels, one patient had a transient partial remission (PR) of 2 weeks duration; the other 5 patients had responses of stable disease (SD). On the 3rddose level, 2 patients obtained responses of stable disease, and one patient obtained a response of very good PR (VGPR) with complete elimination of MM bone disease on positron emission tomography (PET) scan, normalization of serum free light chains, and clearance of bone marrow plasma cells. Toxicity among patients on the first 3 dose levels was mild and included cytopenias attributable to chemotherapy, fever in 3 patients, and signs of cytokine release syndrome including tachycardia and hypotension in Patient 8 who had a VGPR.Two patients have been treated on the highest dose level of 9x106CAR+ T cells/kg. The first patient on this dose level, Patient 10, had MM making up 90% of total bone marrow cells before treatment. Starting 4 hours after infusion of CAR T cells, Patient 10 exhibited signs of cytokine release syndrome including fever, tachycardia, dyspnea, acute kidney injury, coagulopathy, hypotension requiring vasopressor support, and muscle damage manifesting as an elevated creatine kinase level and weakness. His neutrophil count was less than 500/µL before the CAR-BCMA T-cell infusion and remained below 500/µL for 40 days after the CAR T-cell infusion before recovering. He also experienced prolonged thrombocytopenia. Patient 10's myeloma was rapidly eliminated after CAR-BCMA T-cell infusion. By immunohistochemistry staining for CD138, bone marrow plasma cells decreased from 90% before treatment to 0% one month after the CAR T-cell infusion. The serum M-protein decreased from 1.6 g/dL before treatment to undetectable 2 months after treatment. The serum and urine immunofixation electrophoresis tests were negative 2 months after the CAR T-cell infusion. Patient 10's current myeloma response is stringent complete remission.The second patient treated on the 9x106CAR+ T cells/kg dose level, Patient 11, had IgG lambda MM with 80% bone marrow plasma cells before treatment. Patient 11 experienced signs of cytokine release syndrome with toxicities including fever, tachycardia, hypotension, delirium, hypoxia, and coagulopathy. Patient 11's M-protein decreased from 3.6 g/dL before treatment to 0.8 g/dL 4 weeks after treatment. His serum lambda free light chain decreased from 95.9 mg/dL before treatment to 0.15 mg/dL 4 weeks after treatment. Four weeks after CAR T-cell infusion, bone marrow plasma cells were undetectable.T cells containing the CAR-BCMA gene were detected in the blood of all 10 patients evaluated with peak levels of 0.04 to 18.2% of blood mononuclear cells. Patient 10 had the highest peak absolute number of blood CAR T cells with 51 CAR+ T cells/µL. Blood levels of IL-6 and other inflammatory cytokines were highest in patients with clinical signs of cytokine release syndrome, and the 3 patients with the highest serum IL-6 levels also had the most impressive anti-myeloma responses. Before treatment, the mean serum BCMA level of treated patients was 243 ng/mL. In responding patients, serum BCMA levels decreased after treatment. Toxicities in patients receiving CAR-BCMA T cells were similar to toxicities in leukemia patients treated with anti-CD19 CAR T cells. Our findings demonstrate strong anti-myeloma activity in the first clinical trial of a CAR targeting BCMA. Disclosures:Wang:Celgene: Research Funding. Kochenderfer:bluebird bio Inc.: Research Funding. Off Label Use: Use of cyclophosphamide and fludarabine as a conditioning regimen for adoptively-transferred T cells will be part of the presentation.

Collection of Peripheral Blood Stem Cells in Patients with Multiple Myeloma after Stem Cell Transplant: A Single Institution Experience

BackgroundAutologous stem cell transplant is the standard of care for eligible multiple myeloma patients. However, many patients relapse with passage of time. These patients often do not have any or have inadequate numbers of previously harvested stem cells. The question still comes up frequently whether peripheral blood stem cells can be successfully collected from patients with history of prior transplant and what is the best approach. Herein, we report the results from our institution.Patients and MethodsRecords of patients with multiple myeloma who received transplant at our institute between 03/01/12 -07/09/15 dates were reviewed. Recorded data included disease stage, prior transplant and chemotherapies, stem cell mobilization strategies and time to engraftment. Student T-test was performed on reviewed data.ResultsA total number of 21 patients (7 male and 14 female) with multiple myeloma and prior transplant underwent peripheral blood stem cell collection. Median age at diagnosis was 52.1 years (range 36-71 years). Each patient had at least 2 prior rounds of chemotherapy with a median of 4 prior lines of chemotherapies (range 2-6).One patient had a prior history of allotransplant and remainder had at least one prior autotransplant. ISS staging at diagnosis included 5 patients with Stage 1, 2 patients with Stage 2, 5 patients with Stage 3 and stage was not available for 8 patients. One patient had plasma cell leukemia. Disease subtypes included two patients with IgA kappa, one with IgA lambda, nine with IgG kappa, two with IgG lambda, five with kappa light chain, one with lambda light chain and one with non-secretory disease. 33% of patients had high risk cytogenetics at time of stem cell collection.The total number of prior transplants before stem cell collection was 25 with a median of 1 transplant (range 1-2). Median age at the time of collection was 59.3 years (range 43-81). Disease status at time of salvage transplant included complete response in 5 patients, very good partial response in 2, partial response in 9 and stable disease in 5 patients.Filgrastim with plerixafor was used for mobilization in 15 patients, filgrastim, plerixafor and pegfilgrastim in 5 patients and filgrastim with pegfilgrastim in 1 patient. A median number of 3 doses of plerixafor (range 0-5) were used. Median stem cell collection dose was 9.75 X 106/kg CD34 cells (range 3.29-24.8 X 106/kg) and median number of collection days was 3 (range 1-5). All patients received salvage transplants. Engraftment occurred at a median of 12 days (range 10-27). The 21 patients received a total number of 30 transplants after collection with a median of 1 transplant (range 1-2). Prior to collection, D-PACE was administered to 10 patients, VDT-PACE to 2 patients, VCD to 1 patient and growth factors only to 8 patients. 5/8 patients who were mobilized with only growth factors had baseline platelet count of < 130,000. Patients receiving D-PACE had a median collection of 13.55 X 106 cells as compared to 5.70 X 106 cells without it (p<0.004).ConclusionsOur experience shows that collecting peripheral blood stem cells after prior transplantation in patients with multiple myeloma is very feasible even in patients with multiple lines of chemotherapies. Addition of D-PACE as chemo-mobilization strategy has proved to be effective if platelet count is normal at baseline. DisclosuresNo relevant conflicts of interest to declare.

Soluble Bcma in Myeloma Serum Binds Its Ligands BAFF and Prevents Normal Antibody Production in Multiple Myeloma Patients

Introduction: A hallmark of multiple myeloma (MM) is the low levels of uninvolved immunoglobulin (Ig) levels. B-cell maturation antigen (BCMA) is a receptor expressed in mature non-malignant and malignant B lymphocytes, including plasma cells. Its ligands are B-cell activating factor (BAFF) and a proliferation inducing ligand (APRIL). We previously demonstrated that BCMA is present in the serum of MM patients (pts) and that its levels predict survival (Sanchez et al. Br J Haematol 2012). We hypothesized that circulating BCMA binds it ligands, preventing normal plasma cell development in MM patients which may explain their reduction in uninvolved Ig levels.Methods: BCMA-Fc and control Ig were obtained and reconstituted in PBS (R&D Systems). Retro-orbital bleeds were performed on C57 Bl/6 and SCID mice implanted with the human MM xenografts LAGλ-1, LAGk-1A or LAGk-2. Human BCMA and mouse BAFF, IgM, IgA and IgG levels were measured with ELISA (R&D Systems & Bethyl Laboratories). The Raji B-cell line was obtained from the American Type Culture Collection (Rockville, MD, USA). Human IgA and IgG levels were determined in MM patients using nephelometry (Immage 800, Beckman Coulter). Hevylite® Assays (Binding Site) were used to quantify the levels of heavy-light chain isoform pairs in MM patients.Results: We determined if mBAFF formed complexes with human BCMA (hBCMA) in the plasma from SCID mice implanted with LAGλ-1, LAGκ-2 or LAGκ-1A, and were able to identify mBAFF-hBCMA complexes in plasma samples from these mice. To determine what effect human BCMA had on Ig levels in immune competent mice, rhBCMA-Fc or control Ig-Fc (100 mg) was injected into C57 Bl/6 mice, and plasma IgA, IgM and IgG levels were measured. Decreases in IgA levels were observed following BCMA treatment when compared to baseline plasma IgA on days 4 and 6 (P = 0.0031 and P = 0.0064, respectively), and the control group (P = 0.0087 and P = 0.0221). Samples were also analyzed for mouse IgM levels with similar marked reductions when compared to the untreated (P = 0.0001) and Ig-Fc (P = 0.0088) groups. For plasma IgG levels, a marked decrease was observed on day 6 following rhBCMA-Fc administration when compared to its baseline levels (P = 0.0023), and also when compared to the Ig-Fc control protein (P = 0.0014) and the untreated control (P = 0.0129) groups. We then set out to determine if sera from MM patients contained BCMA-BAFF complexes, using ELISA plates coated with an anti-human BAFF antibody followed by exposure to a polyclonal anti-human BCMA antibody. A strong absorbance indicating the presence of BCMA-BAFF complexes was detected in serum samples from MM patients, whereas no antibody cross reactivity was observed in control samples. We also determined whether human MM serum or rhBCMA-Fc blocked BAFF from binding to Raji B-cells. Raji cells (B-cell line) were incubated with serum from a MM patient containing hBCMA (0.75μg/ml) or rhBCMA-Fc (3 μg/ml) in the presence of rhBAFF (500 ng/ml). Myeloma serum and rhBCMA-Fc decreased rhBAFF binding to Raji cells by 71% (from 96.8 to 25.6 %) and 74% (from 96.8 to 22.9 %), respectively. Next, we determined whether serum BCMA levels inversely correlated with uninvolved Ig levels in MM pts. For pts with IgA (n = 134) or IgG (n = 313) MM, higher BCMA levels (> 100 ng/ml) correlated with below normal levels of uninvolved IgG in IgA MM and uninvolved IgA in IgG MM, whereas lower BCMA levels (< 100 ng/ml) correlated with normal uninvolved levels (P < 0.0001). Using the Hevylite Assay, similar results were observed for the levels of BCMA compared to uninvolved IgG isoforms in both pts with involved IgG lambda (n = 62, P = 0.0006) and IgG kappa (n = 117, P < 0.0001) MM.Conclusions: Our laboratory previously has reported that serum levels of BCMA are increased in the serum of MM patients, and correlates with response to treatment and predicts survival. We now demonstrate 1) the formation of complexes of BCMA with its B-cell ligand BAFF in the plasma of MM xenografts and sera of MM patients, 2) show that rhBCMA and MM patient serum blocks the binding of BAFF to human B-cells, 3) administration of rhBCMA to normal mice results in marked reductions in their antibody levels, and 4) show that BCMA levels inversely correlate with uninvolved Ig levels in MM pts. Thus, the lack of normal antibody production in MM pts results, in part, from circulating BCMA binding its ligands, preventing production of normal antibody-producing cells. DisclosuresNo relevant conflicts of interest to declare.

Symptomatic Primary (AL) Amyloidosis of the GIT: Challenging Presentation of a Rare Diagnosis

Introduction: Primary Amyloidosis of the gastrointestinal tract (GIT) without clinical involvement of other organs is extremely rare. We report a unique case of primary GIT Amyloidosis (AL) presenting with severe GI bleeding and ultimately leading to patient demise. Case description: A 68-year-old female with history of diabetes mellitus, coronary artery disease presented with 5-month history of diffuse abdominal pain, nausea, vomiting, and weight loss of about 40 lbs. She underwent upper and lower endoscopy showing ulcerative gastro-duodenitis with partial gastric outlet obstruction and hemorrhagic colitis. Biopsies from stomach and duodenum showed amyloid deposition. Serum and urine protein electrophoresis showed elevated monoclonal protein, IgG lambda type. Serum free lambda chains were also elevated. Both bone marrow and abdominal fat pad biopsies were negative for amyloid deposition. No other major organ systems seemed to be involved. Partial obstruction was managed with nasogastric tube placement and supportive care. Within a few days she developed severe hematemesis. Repeat upper endoscopy showed several mucosal bleeding spots in stomach with evolving submucosal hematomas. Mucosa was extremely friable and bled on minimal contact. Bleeding was eventually controlled with epinephrine injection and argon plasma coagulation. She was started on total parenteral nutrition as gastrostomy or jejunostomy were ruled out given widespread GI involvement with amyloidosis and risk of potentiating bleeding. During the course of next few weeks she continued to have issues with GI bleeding requiring frequent blood transfusions. She was started on cyclophosphamide, bortezomib and dexamethasone (CyBorD) and received 2 cylces. Unfortunately, 2 weeks later she died of acute myocardial infarction in the face of worsening anemia and need to withhold anti-platelets. Discussion: This is a rare presentation of Primary Amyloidosis limited to GIT. Our case has several unique features and learning points. Amyloidosis of GIT should be considered in patients with multiple GI complaints and pathologist should always rule it out even in absence of other organ system involvement. GI bleeding from amyloidosis is rare but can be extremely challenging and even be potentially fatal in the absence of amyloid-targeted therapy. Nasogastric tube placement in such patients can precipitate bleeding. The role of myelosuppressive chemotherapy in the absence of bone marrow involvement and in the presence of GI bleeding is debatable.Figure 1Figure 2Figure 3

Plasma cell leukemia mimicking hairy cell leukemia

A42-year-old female presented with fever and shortness of breath, and was diagnosed with community acquired pneumonia. On presentation she was found to have a white cell count of 13 · 10/L, hemoglobin of 7.1 g/dL and platelets of 51 · 10/L. Peripheral blood smear showed left shift and many cells with hairy projections (56%) (See Fig. 1) that were positive for CD38 and CD138 by peripheral blood flow cytometry. Other laboratory findings included B-2 microglobulin of 15.3 mg/L with normal creatinine and calcium levels. Serum protein electrophoresis evaluation revealed monoclonal gammopathy (IgG-lambda) of 45.87 g/L. Urine protein electrophoresis showed the presence of Ig-G lambda as well as free-lambda light chain monoclonal bands. Bone marrow biopsy showed increased cellularity (95%) with increased number of plasma cells (45%). Flow cytometry showed 44% of the cells to have clonal plasma cell phenotype (CD38+ve, CD138+ve, CD20 ve, CD22 ve, and cytoplasmic lambda light chin restriction). A diagnosis of plasma cell leukemia was made and treatment was started with bortezomib, cyclophosphamide, and dexamethasone. The patient achieved partial remission. Treatment was followed by autologous bone marrow transplantation and then two cycles of lenalidomide and dexamethasone consolidation. The patient subsequently achieved complete remission. She has been on maintenance lenalidomide over the past six months and continues to be in complete remission.

Case 8-2015

Presentation of Case Dr. Naina Rastalsky (Medicine): A 68-year-old man with multiple myeloma was seen in the rheumatology clinic of this hospital because of increasing skin tightness, joint pain, and swelling of the hands and feet. The patient had been well until 2 years before this presentation, when anemia was noted on routine examination at another hospital. During the next 7 months, endoscopic and colonoscopic screening examinations were negative. Pathological examination of a bone marrow–biopsy specimen and aspirate revealed 30% plasma cells; flow-cytometric studies revealed an IgG lambda M component. A diagnosis of multiple myeloma was made. Skeletal radiographs reportedly . . .

Immunoparesis in MGUS - Relationship of uninvolved immunoglobulin pair suppression and polyclonal immunoglobuline levels to MGUS risk categories.

Monoclonal gammopathy of undetermined significance (MGUS) is an asymptomatic, potentially malignant condition. It has been established that annually approximately 1-2% of MGUS cases transforms into one of the malignant forms of monoclonal gammopathies. Progression risk factors include the quantity and type of M-protein, and namely the ratio of free light immunoglobulin chains (FLC). These factors, enable purposeful stratification of MGUS individuals. Some authors consider suppression of polyclonal immunoglobulin levels to be another progression factor. The aim of the study was to compare polyclonal immunoglobulin (PIg) levels with uninvolved heavy/light chain pair (HLC) levels in order to verify the degree of immunoparesis depending on MGUS risk category (0-3). The analyzed set consisted of 159 serum samples from MGUS patients (102 IgG, 57 IgA), who were stratified into 4 risk groups (0 - low, 1 - low-intermediate, 2 - high-intermediate and 3 - high risk of transformation). The results of analysis showed that with increasing degree of MGUS increases risk of immune paresis defined by decreasing levels of polyclonal immunoglobulins, ie. IgA and IgM in the case of IgG MGUS, respectively, IgG and IgM in case of IgA MGUS. Significant differences were also found when analyzing the levels of uninvolved HLC pairs IgG kappa (resp. IgG lambda) in IgG lambda (IgG kappa) dominant secretion. In the case of MGUS with IgA isotype, the results were similar. Discovery of the connection between the degree of immunosuppression and the level of MGUS risk contributes to our understanding of the relationship between biology, development and potential malignant transformation of MGUS. It is apparent that uninvolved HLC pair assay enables more reliable identification of at-risk MGUS patients than asimple quantitative assay for polyclonal immunoglobulins alone.

A Case of AL Amyloidosis

Case: 45 year old lady presented with anorexia, weakness for last one year and development of deformity in her spine for last one and half years following fracture. On clinical examination she had mild bilateral pedal edema, kyphoscoliosis, tenderness over rib cage on left side. MRI spine showed diffuse marrow edema in D5 D6 D7 D9 D10 and L4 vetrbral bodies and posterior elements with subtle decrease in anterior height and associated paraspinal muscle edema seen. There was osteophytic bulge with ligamentum flavum thickening at c4-c5 and c5-c6 levels causing spinal canal and bilateral neural foraminal narrowing with nerve root impingement. Blood tests showed Hb-16.5, calcium-7.5, serum albumin-1.2, and globulin-4. Urinary albumin +++. Urinary 24hr protein was 7.81 gram. On skeletal survey no lytic lesion was found. Whole body scan showed abnormal tracer uptake involving multiple dorsal and lumber vetebrae, sternum multiple ribs on either side anteriorly. Serum electrophoresis revealed biclonal IgG and IgA and lambda light chain paraproteins. On bone marrow examination there were 50% plasma cells

A Phase I Study of Carfilzomib and Pegylated Liposomal Doxorubicin for Relapsed or Refractory Multiple Myeloma

Background: Despite improvements in overall survival (OS) and progression free survival (PFS), the prognosis of patients with relapsed/refractory multiple myeloma (RRMM) remains poor. Carfilzomib (CFZ), a second generation proteasome inhibitor, is active as a single-agent or in combination with lenalidomide and/or dexamethasone (DEX) in RRMM. Pegylated liposomal doxorubicin (PLD) combined with bortezomib has been shown to prolong PFS and OS and is FDA approved as combination therapy in MM. We investigated the combination of CFZ with PLD in RRMM in a Phase I study.Objective: To determine the maximum tolerated dose (MTD) of CFZ combined with PLD.Patient/Methods: Patients with RRMM after ≥ 1 lines of therapy, with measureable disease, and good performance status, organ function and hematological reserve were eligible. Prior CFZ or PLD/doxorubicin exposure was not exclusionary.CFZ was given on days 1, 2, 8, 9, 15 and 16 at escalating doses of 27-56mg/m2 and PLD was given on day 8 in 28 day cycles at a dose of 30mg/m2. All dose levels included a lead-in dose of 20mg/m2 of CFZ on days 1 and 2 of cycle 1. Following 6 cycles of combination therapy, PLD was discontinued and patients were treated with maintenance CFZ (once weekly).Dose escalation was performed using a 3+3 design; MTD was defined as the highest dose level where dose limiting toxicity (DLT) occurred in less than 2 of 6 patients. Disease response was determined using International Myeloma Working Group (IMWG) criteria.Results: 16 patients were enrolled from May 2012-March 2014. Median age was 66 years (range 53-79) and 11 were female. Seven patients were ISS stage 3, 9 were stage 1. 3 patients had > 50% plasma cells present on bone marrow aspirate, 8 had < 20%. By mSMART criteria, 2 patients were high-risk, 2 were intermediate-risk, and 12 were standard-risk. Most patients were IgG Kappa subtype (12); while 3 patients had Kappa light chain subtype, and 1 had IgG Lambda subtype.Median number of prior therapies was 3 (range 1-12). Median time from diagnosis to start of protocol was 42 months (range 9-236). 100% had prior exposure to lenalidomide; 87.5% had prior exposure to bortezomib; 75% had undergone autologous transplantation; 6% had prior PLD or doxorubicin exposure; and 6% had prior CFZ exposure.No DLTs were observed in any cohort. Two patients were unable to complete the first cycle of treatment due to early progressive disease, and were replaced. Grade 3/4 non-hematologic adverse events were rare, but included: UTIs (3), sepsis (2), pneumonitis (2), dyspnea (2), syncope (1), pleural effusion (1).Grade 3/4 hematologic AEs were limited to: anemia (7), thrombocytopenia (4), neutropenia (5), lymphopenia (4), and hemolysis (2). Most of the neutropenia (60%) and thrombocytopenia (75%) occurred in the 56mg/m2 cohort.The median number of cycles completed was 3.5 (range <1-13). Disease progression caused discontinuation in 10 patients. Adverse events were the reason for 2; one patient had dyspnea after 2 cycles, one patient had hand-foot syndrome after 3 cycles. Four patients were on treatment at time of submission.56% of patients had a partial response or better, including 80% treated at the maximum dose level. The median duration of response was 6.9 months. Individual patient responses are summarized in Table 1.Conclusion: Co-administration of CFZ and PLD is well tolerated and an MTD was not reached despite utilizing the approved single agent doses. Recommended dosage for further studies is: CFZ 56mg/m2 and PLD 30mg/m2. Subsequent phase I dose escalation of a 3 drug regimen CDD (CFZ-PLD-DEX) is ongoing at abstract submission and will be reported at the meeting.Table 1IDDose Level (CFZ;PLD)# of Prior Lines of TherapyPrior ASCT# of CyclesBest Response$PFS (months)11 (27mg/m2;30mg/m2)3Y7PR6.221 (27mg/m2;30mg/m2)7N7SD6.731 (27mg/m2;30mg/m2)3N3SD1.842 (36mg/m2;30mg/m2)4Y8PR6.952 (36mg/m2;30mg/m2)12Y<1PD0.862 (36mg/m2;30mg/m2)3Y3SD2.172 (36mg/m2;30mg/m2)1N2PR3.783 (45mg/m2;30mg/m2)3Y3SD1.993 (45mg/m2;30mg/m2)5N<1PD0.2103 (45mg/m2;30mg/m2)1Y3VGPR3.4113 (45mg/m2;30mg/m2)1Y13*PR12.8*124 (56mg/m2;30mg/m2)2Y4PR3.5134 (56mg/m2;30mg/m2)8Y11*VGPR10.5*144 (56mg/m2;30mg/m2)1Y8*VGPR8.4*154 (56mg/m2;30mg/m2)5Y2PD1164 (56mg/m2;30mg/m2)2Y5*PR4.5** Ongoing at abstract submission$ PR: partial response, SD: stable disease; VGPR: very good partial response; PD: progressive disease DisclosuresStockerl-Goldstein:Onyx: Speakers Bureau.

Circulating Bcma Binding to Its Ligand BAFF Prevents Normal Antibody Production in Multiple Myeloma Patients

Introduction: A hallmark of multiple myeloma (MM) is the low levels of uninvolved immunoglobulin (Ig) levels. B-cell maturation antigen (BCMA) is a receptor expressed in mature non-malignant and malignant B lymphocytes, including plasma cells. Its ligands are BAFF (B-cell activating factor) and APRIL (a proliferation inducing ligand). We previously demonstrated that BCMA is present in the serum of MM patients (pts) and that its levels predict survival (Sanchez et al. Br J Haematol 2012). We hypothesized that circulating BCMA binds it ligands, preventing normal plasma cell development in MM patients which may explain their reduction in uninvolved Ig levels.Methods: BCMA-Fc and control Ig were obtained and reconstituted in PBS (R&D Systems). Retro-orbital bleeds were performed on SCID mice implanted with the human xenografts LAGλ-1, LAGk-1A or LAGk-2 following BCMA treatment. Human BCMA and mouse BAFF, IgM and IgA levels were measured with ELISA (R&D Systems & Bethyl Laboratories). Human IgA and IgG levels were determined in MM patients using nephelometry (Immage 800, Beckman Coulter). Hevylite® Assays (Binding Site) were used to quantify the levels of heavy-light chain isoform pairs in MM patients.Results: Recombinant mouse BAFF (rmBAFF) was mixed with recombinant human BCMA (rhBCMA) and incubated on plates coated with anti-mouse BAFF antibody (Ab). An anti-BCMA detection Ab was added, and BCMA-BAFF complexes were easily detected at concentrations of human BCMA and BAFF present in MM pts. We determined if mBAFF from SCID mice would also bind rhBCMA. SCID mice were bled; their plasma isolated and incubated with rhBCMA, and showed that rhBCMA formed complexes with mBAFF.To determine what effect human BCMA had on Ig levels in immune competent mice, rhBCMA-Fc or control Ig-Fc (100 mg) was injected into C57 Bl and Balb/c mice, and plasma IgA and IgM levels were measured. Following rhBCMA-Fc injection, a marked decrease in both antibody classes was observed in both mouse strains. Decreases in IgA levels were observed following BCMA treatment when compared to baseline plasma IgA on days 4 and 6 (P = 0.0031 and P = 0.0064, respectively), and the control groups (P = 0.0087 and P = 0.0221). Samples were also analyzed for mouse IgM levels with similar marked reductions when compared to the untreated (P = 0.0001) and Ig-Fc (P = 0.0088) groups. To determine if rhBCMA-mBAFF complexes formed in vivo, an ELISA was performed. Plates were pre-coated with a monoclonal mouse anti-BAFF capture Ab. Plasma samples were incubated and an anti-human-BCMA detection Ab was added. rhBCMA-mBAFF complexes were detected at high levels in plasma samples from mice dosed 4 and 6 days previously with BCMA-Fc whereas no complexes were found in samples in control Ig-Fc or untreated mice. We evaluated mBAFF levels in SCID mice with and without human MM. We have previously shown high levels of human BCMA in the plasma of MM tumor-bearing mice (Sanchez et al. Br J Haematol 2012). On days 14, 21 and 28 post-tumor implantation, mice implanted with LAGλ-1 had markedly lower plasma levels of mBAFF (P = 0.0143, P = 0.0002 and P = 0.0008, respectively) when compared to age and sex-matched mice not bearing any tumors. We obtained similar results using two additional human MM xenograft models (LAGk-1A and LAGk-2). Next, we determined whether serum BCMA levels inversely correlated with uninvolved Ig levels in MM pts. For pts with IgA (n = 134) or IgG (n = 313) MM, higher BCMA levels (> 100 ng/ml) correlated with below normal levels of uninvolved IgG in IgA MM and uninvolved IgA in IgG MM, whereas lower BCMA levels (< 100 ng/ml) correlated with normal uninvolved levels (P < 0.0001). Using the Hevylite Assay, similar results were observed for the levels of BCMA compared to uninvolved IgG isoforms in both pts with involved IgG lambda (n = 62, P = 0.0006) and IgG kappa (n = 117, P < 0.0001) MM.Conclusions: Our laboratory previously reported that BCMA is present in the serum of MM patients, correlates with response to treatment and predicts survival. We now demonstrate the formation of circulating BCMA-BAFF complexes in MM, and administration of recombinant BCMA to normal mice results in marked reductions in their antibody levels. We also show that BCMA levels inversely correlate with uninvolved Ig levels in MM pts. Thus, the lack of normal antibody production in MM pts results in part from circulating BCMA binding its ligands, preventing production of normal antibody-producing cells. DisclosuresNo relevant conflicts of interest to declare.