Immunoglobulin-Storing Histiocytosis: A Case Based Systemic Review

Crystal-storing histiocytosis (CSH) is a rare event in disorders associated with monoclonal gammopathy and is mostly associated with the accumulation of immunoglobulins (Igs) in the cytoplasm of histiocytes. In this article, we present a case of a 75-year-old female with IgG kappa monoclonal gammopathy of undetermined significance (MGUS) and signs of a non-crystallized version of immunoglobulin-storing histiocytosis (IgSH) in a vertebra corpus. Furthermore, we performed a literature review based on all cases of storing histiocytosis identified by literature search between 1987 and 2020 and identified 140 cases in total. The median age at diagnosis was 60 years (range 18–91), with an equal sex distribution (51% men). The majority of the patients had an underlying neoplastic B-cell disorder, most often multiple myeloma (MM), MGUS, or lymphoplasmacytic lymphoma (LPL). The main affected organ systems or tissue sites were bone (n = 52), followed by head and neck (n = 31), kidney (n = 23), lung (n = 20), and gastrointestinal (GI)-tract (n = 18). IgG was the main immunoglobulin class involved, and most cases were associated with kappa light chain expression. We conclude that IgSH is a rare disease entity but should be considered with unusual findings in several organ systems associated with monoclonal gammopathy, especially with kappa light chain expression.

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Unusual case of amyloidosis presenting as a jejunal mass

BMJ Case Reports ◽

10.1136/bcr-2020-240226 ◽

2021 ◽

Vol 14 (5) ◽

pp. e240226

Author(s):

Sachin Mohan ◽

Elliot Graziano ◽

James Campbell ◽

Irshad H Jafri

Keyword(s):

Small Intestine ◽

Light Chain ◽

Protein Misfolding ◽

Unusual Case ◽

Gi Tract ◽

Organ Systems ◽

Light Chain Disease ◽

Wide Range ◽

Amyloid Light Chain ◽

Possible Cause

Amyloidosis constitutes a heterogeneous group of disorders of protein misfolding that can involve different organ systems. The disease can occur either in a systemic or localised manner that is well known to involve the gastrointestinal (GI) tract. GI amyloidosis can present with a wide range of symptoms including diarrhoea, bleeding and obstruction. This case illustrates a patient with localised jejunal amyloid light chain disease that was diagnosed serendipitously during a workup for haematuria. Our patient was otherwise asymptomatic, but this case underscores the importance of considering amyloidosis as a possible cause of isolated masses of the small intestine.

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Monoclonal Gammopathy in An African American Cohort From a VA Medical Center.

Blood ◽

10.1182/blood.v114.22.4869.4869 ◽

2009 ◽

Vol 114 (22) ◽

pp. 4869-4869

Author(s):

Avni M Desai ◽

Richard L Amdur ◽

Min-Ling L Liu ◽

Joao Ascensao ◽

Dalia Mobarek ◽

...

Keyword(s):

African American ◽

Plasma Cell ◽

Light Chain ◽

Monoclonal Gammopathy ◽

Medical Center ◽

Kaplan Meier ◽

Plasma Cell Disorder ◽

Actuarial Risk ◽

Cell Disorder ◽

Bence Jones Proteinuria

Abstract Abstract 4869 The information regarding monoclonal gammopathy of unknown significance (MGUS) derives mainly from studies of Caucasian individuals. In contrast, this study describes the characteristics of 492 African American (AA) male patients identified with MGUS from the electronic database at the Washington VAMC. Review of their individual electronic records showed that none of the patients initially had evidence of myeloma or other symptomatic plasma cell or lymphoproliferative disorder. The median age at diagnosis of MGUS was 68 years old (range 28.5 to 95.6 years). The distribution of monoclonal immunoglobulin (M Ig) subtypes were IgG 78.1%, IgA 14.8%, IgM 6.9%; light chain only in the urine 2.9% or in the serum 1.0%, The light chain distribution of the M Igs was 60% kappa, 40% lambda. Fifty-nine patients (12%) had diclonal and 4 (0.8%) had triclonal M Igs. The median amount of M Ig was 0.26 g/dL; 47.8% were too small to quantitate. Ninety-four (25.5%) of 368 tested had Bence-Jones proteinuria, with a similar kappa:lambda distribution and 4 patients showed both light chains. Clinical characteristics were as follows: hepatitis C 15.5%, HIV 5.1%, other significant infections 26.8%, and chronic autoimmune or inflammatory disorders 10.3%. The patients were followed clinically for a median of 4.1 years (range 0.35 to 21.02 years), and the median interval between the first and last electrophoresis was 1.41 years (range 0 to 19.97 years). During this period 21 patients (4.3%) progressed to a malignant plasma cell disorder (myeloma 20, solitary plasmacytoma 1). 133 patients (27.0%) died of other causes, and in 26 (5.3%) the M protein had resolved. The actuarial risk determined by a Kaplan Meier plot of progression to a symptomatic plasma cell disorder was 13.5 % at 11 years. The initial M Ig in the patients who progressed was IgG in 15, IgA in 4, and isolated BJ proteinuria in 2. The only recognized predicting characteristic for progression was the detection of Bence-Jones proteinuria at diagnosis of MGUS: Thirteen of 20 (65%) progressing patients tested were positive as compared to 81 of 348 (23.0%) of the non-progressors (p = .0003) A number of features distinguish this AA MGUS cohort from previous series of Caucasian patients. MGUS was detected at an earlier age: 8.9% (5.2% excluding HCV and HIV patients) were under the age of 50. The percentage of AA patients with very low level M proteins was more than threefold that previously reported. The percentage of patients with IgM M Ig was less than one-half noted in previous studies. The actuarial risk of progression to a symptomatic plasma cell disorder as calculated from a Kaplan Meier plot appears to be comparable to previous reports in predominantly Caucasian series. Dr. Desai worked on this project following completion of her internal medicine residency. She is now a Hematology Oncology fellow at Montefiore Medical Center, New York NY. Disclosures No relevant conflicts of interest to declare.

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Incidentally Detected Amyloid Light-Chain Amyloidosis Caused by Monoclonal Gammopathy of Undetermined Significance: Possible Time-Dependent Change in Colonic Findings

Case Reports in Gastroenterology ◽

10.1159/000494919 ◽

2018 ◽

Vol 12 (3) ◽

pp. 737-746

Author(s):

Toshiro Fukui ◽

Yuji Tanimura ◽

Yasushi Matsumoto ◽

Shunsuke Horitani ◽

Takashi Tomiyama ◽

...

Keyword(s):

Plasma Cell ◽

Light Chain ◽

Monoclonal Gammopathy ◽

Amyloid Deposition ◽

Fecal Occult Blood ◽

Al Amyloidosis ◽

Plasma Cell Disorder ◽

Amyloid Light Chain ◽

Cell Disorder ◽

Undetermined Significance

Amyloid light-chain (AL) amyloidosis is associated with plasma cell disorder and monoclonal light chains. This type of amyloidosis is the prominent type involving the gastrointestinal tract. Monoclonal gammopathy of undetermined significance (MGUS) is the most common plasma cell disorder and a known precursor of more serious diseases. A 72-year-old male was treated for high blood pressure, diabetes, and gout at the clinic of a private physician. Due to a positive fecal occult blood test discovered during colon cancer screening, he underwent colonoscopy and was diagnosed with adenomatous polyps by biopsies. Two months later, he was referred to our hospital for endoscopic resection of the polyps. Although the polyps were successfully removed, a colonoscopy revealed two types of ulcerative lesions. Immunohistopathological evaluations obtained from these lesions and polyps confirmed amyloid deposition. Although esophagogastroduodenoscopy results were normal, a biopsy specimen from the patient’s stomach showed the same type of amyloid deposition. Immunoelectrophoresis showed M-proteins for anti-IgG-λ in the serum and λ type Bence-Jones protein in the urine. His blood, bone marrow, and urine test results led to a diagnosis of MGUS. A coronary angiography revealed multivessel stenosis, and the patient’s cardiac function improved after coronary artery stenting. Hereafter, a combination therapy with bortezomib, lenalidomide, and dexamethasone is planned. This is a case report of systemic AL amyloidosis caused by MGUS, which was incidentally detected by colonoscopy.

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Hepatitis B Associated Monoclonal Gammopathy That Resolved after Successful Liver Transplant

Journal of Transplantation ◽

10.1155/2009/103784 ◽

2009 ◽

Vol 2009 ◽

pp. 1-3

Author(s):

P. Sreenivasan ◽

S. Nair

Keyword(s):

Multiple Myeloma ◽

Liver Transplantation ◽

Hepatitis B ◽

Light Chain ◽

Monoclonal Gammopathy ◽

Lymphoproliferative Disorders ◽

M Protein ◽

Kappa Light Chain ◽

Hepatitis B Infection ◽

Undetermined Significance

Monoclonal gammopathy of undetermined significance (MGUS) has been most commonly associated with diseases like multiple myeloma, Waldenstrom's macroglobulinemia, primary systemic amyloidosis, HIV, and other lymphoproliferative disorders. There has been an isolated report of MGUS in patients coinfected with HIV and Hepatitis B, as the work by Amara et al. in 2006. Here, we report a case of IgA-kappa light chain gammopathy secondary to Hepatitis B infection, which resolved after liver transplantation. To our knowledge, this is the first reported case of M protein spike seen in the context of Hepatitis B infection only.

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Dose-Intensive Melphalan With Blood Stem-Cell Support for the Treatment of AL (Amyloid Light-Chain) Amyloidosis: Survival and Responses in 25 Patients

Blood ◽

10.1182/blood.v91.10.3662 ◽

1998 ◽

Vol 91 (10) ◽

pp. 3662-3670 ◽

Cited By ~ 247

Author(s):

Raymond L. Comenzo ◽

Evan Vosburgh ◽

Rodney H. Falk ◽

Vaishali Sanchorawala ◽

Johann Reisinger ◽

...

Keyword(s):

Plasma Cell ◽

Light Chain ◽

Performance Status ◽

Al Amyloidosis ◽

Organ Systems ◽

Plasma Cell Disorders ◽

Plasma Cell Disorder ◽

Amyloid Light Chain ◽

Al Amyloid ◽

Cell Disorder

Abstract AL (amyloid light-chain) amyloidosis is an uncommon plasma cell disorder in which depositions of amyloid light-chain protein cause progressive organ failure and death in a median of 13 months. Autologous stem-cell transplantation is effective therapy for multiple myeloma and therefore, we evaluated its efficacy for AL amyloidosis. Patients with adequate cardiac, pulmonary, and renal function had stem cells mobilized with granulocyte-colony stimulating factor and were treated with dose-intensive intravenous melphalan (200 mg/m2). Response to therapy was determined by survival and improvement of performance status, complete response or persistence of the clonal plasma cell disorder, and change in the function of organs involved with amyloid at baseline. We enrolled 25 patients with a median age of 48 years (range, 29-60), all of whom had biopsy-proven amyloidosis with clonal plasma cell disorders. Twenty-two (88%) were Southwest Oncology Group performance status 1 or 2 within a year of diagnosis, and 16 (64%) had received no prior therapy. Predominant amyloid-related organ involvement was cardiac (n = 8), renal (n = 7), hepatic (n = 6), neuropathic (n = 3), and lymphatic (n = 1). Fifteen patients had one or two organ systems involved, whereas 10 had three or more involved. With a median follow-up of 24 months (12-38), 17 of 25 patients (68%) are alive, and the median survival has not been reached. Thirteen of 21 patients (62%) evaluated 3 months posttransplant had complete responses of their clonal plasma cell disorders. Currently, two thirds of the surviving patients (11 of 17) have experienced improvements of amyloid-related organ involvement in all systems, whereas 4 of 17 have stable disease. The improvement in the median performance status of the 17 survivors at follow-up (0 [range, 0-3]) is statistically significant versus baseline (2 [range, 1-3]; P < .01). Significant negative prognostic factors with respect to overall survival include amyloid involvement of more than two major organ systems and predominant cardiac involvement. Three patients have experienced relapses of the clonal plasma cell disorder at 12 and 24 months. Dose-intensive therapy should currently be considered as the preferred therapy for patients with AL amyloidosis who meet functional criteria for autologous transplantation.

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Free Light-Chain Levels in Patients with Transthyretin Amyloid Cardiomyopathy in Attr-ACT

Blood ◽

10.1182/blood-2021-148691 ◽

2021 ◽

Vol 138 (Supplement 1) ◽

pp. 3787-3787

Author(s):

James E Hoffman ◽

Marla B. Sultan ◽

Balarama Gundapaneni ◽

Ronald Witteles

Keyword(s):

Plasma Cell ◽

Light Chain ◽

Monoclonal Gammopathy ◽

Research Funding ◽

Publicly Traded ◽

Monoclonal Gammopathies ◽

Plasma Cell Disorder ◽

The Mean ◽

Amyloid Cardiomyopathy ◽

Cell Disorder

Abstract Introduction: In cardiac amyloidosis (CA), immunoglobulin-derived light chains (AL) and transthyretin (TTR) are the most common amyloidogenic proteins infiltrating the heart. 1 Identification of the specific precursor protein leading to amyloid deposition is needed to establish the correct therapeutic approach. 2 In both AL- and TTR-related CA, an early and accurate diagnosis is critical to achieving the best treatment outcomes. TTR amyloid cardiomyopathy (ATTR-CM) is often misdiagnosed as other causes of heart failure (HF), including AL CA. 3 While almost all patients with AL amyloidosis have elevated serum free light-chain (sFLC) levels and abnormal free kappa:lambda (κ:λ) ratios, 4 patients with ATTR-CM can also have abnormal sFLC levels due to either an unrelated monoclonal gammopathy or relative κ-predominance in renal dysfunction. 2,5 Because ATTR-CM most often occurs in elderly adults and is commonly accompanied by renal comorbidity, we theorized that patients with ATTR-CM may have κ:λ ratios that approach, or exceed, the upper limit of the normal reference range (0.26-1.65 6). High light-chain ratios in these patients have the potential to increase the likelihood of misdiagnosis of a monoclonal plasma cell disorder and may lead to unnecessary referrals to hematologists and/or inappropriate treatments. To explore this theory, we evaluated κ:λ ratios in patients with biopsy-proven ATTR-CM who were enrolled in the Tafamidis in Transthyretin Cardiomyopathy Clinical Trial (ATTR-ACT). 7 Methods: In ATTR-ACT, a double-blind, placebo-controlled, randomized study, patients with biopsy-proven ATTR-CM, and without light-chain amyloidosis, received tafamidis or placebo for 30 months. In the current analysis, sFLC levels and κ:λ ratios were assessed in the intent-to-treat population (N=441), excluding patients with a prior diagnosis of monoclonal gammopathies (n=13; defined by MedDRA preferred terms: 'monoclonal gammopathy', 'plasma cell myeloma', 'plasma cell disorder', and 'hypergammaglobulinemia benign monoclonal'). Subgroup analyses were performed by estimated glomerular filtration rate (eGFR) category (≥60 vs ≥40 to <60 vs <40 mL/min/1.73 m 2). Findings were summarized using descriptive statistics (min/max, mean, median, and interquartile range [IQR]). Results: In 422 patients with ATTR-CM and available sFLC data, and without a prior diagnosis of monoclonal gammopathies, the mean κ:λ ratio was 1.45 (median, 1.20 [IQR, 0.98, 1.47]) (Figure). The ratio increased with declining renal function: eGFR ≥60 mL/min/1.73 m 2, mean, 1.25 (median [IQR], 1.11 [0.94, 1.38]); ≥40 to <60 mL/min/1.73 m 2, 1.52 (1.22 [0.99, 1.49]); and <40 mL/min/1.73 m 2, 1.62 (1.30 [1.05, 1.68)]. Conclusions: In patients with biopsy-proven ATTR-CM without known monoclonal gammopathies who were enrolled in ATTR-ACT, the mean κ:λ ratio showed a κ-predominance, often exceeding the upper range of normal in patients with more advanced kidney dysfunction. The findings suggest that individuals with ATTR-CM can have higher sFLC levels than those normally seen in the general population, and such elevations do not necessarily indicate the presence of monoclonal gammopathy of undetermined significance or AL CA. In an era when most patients with ATTR-CM and without monoclonal gammopathies are diagnosed noninvasively using bone scintigraphy, age- and renal-function-based sFLC norms are critical to ensure appropriate use of diagnostic testing modalities. References: 1. Maleszewski JJ. Cardiovasc Pathol. 2015;24:343-50. 2. Donnelly JP, et al. Cleve Clin J Med. 2017;84:12-26. 3. Witteles RM, et al. JACC Heart Fail. 2019;7:709-716. 4. Falk RH, et al. J Am Coll Cardiol. 2016;68:1323-41. 5. Geller HI, et al. Mayo Clin Proc. 2017;92:1800-5. 6. Katzmann JA, et al. Clin Chem. 2002;48:1437-44. 7. Maurer MS, et al. N Engl J Med. 2018;379:1007-16. Figure 1 Figure 1. Disclosures Hoffman: BMS, Celgene: Honoraria. Sultan: Pfizer: Current Employment, Current equity holder in publicly-traded company. Gundapaneni: Pfizer: Current Employment, Current equity holder in publicly-traded company. Witteles: Pfizer: Honoraria, Research Funding; Alnylam: Honoraria, Research Funding; Eidos: Research Funding.

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Dose-Intensive Melphalan With Blood Stem-Cell Support for the Treatment of AL (Amyloid Light-Chain) Amyloidosis: Survival and Responses in 25 Patients

Blood ◽

10.1182/blood.v91.10.3662.3662_3662_3670 ◽

1998 ◽

Vol 91 (10) ◽

pp. 3662-3670 ◽

Cited By ~ 3

Author(s):

Raymond L. Comenzo ◽

Evan Vosburgh ◽

Rodney H. Falk ◽

Vaishali Sanchorawala ◽

Johann Reisinger ◽

...

Keyword(s):

Plasma Cell ◽

Light Chain ◽

Performance Status ◽

Al Amyloidosis ◽

Organ Systems ◽

Plasma Cell Disorders ◽

Plasma Cell Disorder ◽

Amyloid Light Chain ◽

Al Amyloid ◽

Cell Disorder

AL (amyloid light-chain) amyloidosis is an uncommon plasma cell disorder in which depositions of amyloid light-chain protein cause progressive organ failure and death in a median of 13 months. Autologous stem-cell transplantation is effective therapy for multiple myeloma and therefore, we evaluated its efficacy for AL amyloidosis. Patients with adequate cardiac, pulmonary, and renal function had stem cells mobilized with granulocyte-colony stimulating factor and were treated with dose-intensive intravenous melphalan (200 mg/m2). Response to therapy was determined by survival and improvement of performance status, complete response or persistence of the clonal plasma cell disorder, and change in the function of organs involved with amyloid at baseline. We enrolled 25 patients with a median age of 48 years (range, 29-60), all of whom had biopsy-proven amyloidosis with clonal plasma cell disorders. Twenty-two (88%) were Southwest Oncology Group performance status 1 or 2 within a year of diagnosis, and 16 (64%) had received no prior therapy. Predominant amyloid-related organ involvement was cardiac (n = 8), renal (n = 7), hepatic (n = 6), neuropathic (n = 3), and lymphatic (n = 1). Fifteen patients had one or two organ systems involved, whereas 10 had three or more involved. With a median follow-up of 24 months (12-38), 17 of 25 patients (68%) are alive, and the median survival has not been reached. Thirteen of 21 patients (62%) evaluated 3 months posttransplant had complete responses of their clonal plasma cell disorders. Currently, two thirds of the surviving patients (11 of 17) have experienced improvements of amyloid-related organ involvement in all systems, whereas 4 of 17 have stable disease. The improvement in the median performance status of the 17 survivors at follow-up (0 [range, 0-3]) is statistically significant versus baseline (2 [range, 1-3]; P < .01). Significant negative prognostic factors with respect to overall survival include amyloid involvement of more than two major organ systems and predominant cardiac involvement. Three patients have experienced relapses of the clonal plasma cell disorder at 12 and 24 months. Dose-intensive therapy should currently be considered as the preferred therapy for patients with AL amyloidosis who meet functional criteria for autologous transplantation.

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From light chain deposition to multiple myeloma – Case report and literature review

Portuguese Journal of Nephrology & Hypertension ◽

10.32932/pjnh.2021.01.104 ◽

2021 ◽

Vol 34 (4) ◽

Author(s):

Ana Domingos ◽

◽

Joana Vidinha ◽

Anabela Guedes ◽

Ana Macedo ◽

...

Keyword(s):

Multiple Myeloma ◽

Light Chain ◽

Monoclonal Gammopathy ◽

Monoclonal Immunoglobulin ◽

Monoclonal Immunoglobulin Deposition Disease ◽

Deposition Disease ◽

Malignant Plasma Cell ◽

Plasma Cell Disorder ◽

Light Chain Deposition ◽

Cell Disorder

Monoclonal gammopathies consist of a broad spectrum of diseases, ranging from asymptomatic monoclonal gammopathy of undetermined significance to multiple myeloma (MM). Multiple myeloma is a malignant plasma cell disorder and accounts for 10% of all hematological malignancies and 1% of all malignancies. Differential diagnosis may be challenging, considering the variety of clinical entities with similar behavior. About 15‑20% of MM only secretes monoclonal light chains, called light chain MM, which is associated with poorer outcome. Two intermediate concepts were recently introduced, monoclonal gammopathy of renal significance (MGRS) and a wider concept of monoclonal gammopathy of clinical significance (MGCS). The former behaves as a clonal proliferative disorder with associated nephrotoxicity, but does not have the hematological criteria for MM, while MGCS expands this concept to other organs. A subtype of MGCS is monoclonal immunoglobulin deposition disease, a multisystemic disorder characterized by light or heavy chain deposition of monoclonal immunoglobulin in various organs and encompasses three clinical entities: Light‑Chain, Light‑ and Heavy‑Chain, and Heavy‑Chain Deposition Disease (LCDD, LHCDD and HCDD, respectively). We describe an unusual case of LCDD in which MM was subsequently considered although the proposed criteria are not met. We demonstrate the variability of clinical‑pathological presentation of LCDD, requiring a rapid decision‑making, particularly in terms of kidney and survival outcomes.

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Immune-mediated chorea in a patient with kappa light-chain monoclonal gammopathy

Annals of Movement Disorders ◽

10.4103/aomd.aomd_13_20 ◽

2020 ◽

Vol 3 (2) ◽

pp. 112

Author(s):

Roopa Rajan ◽

AmritaJ Gotur ◽

Rishi Dhawan ◽

Ajay Garg

Keyword(s):

Light Chain ◽

Monoclonal Gammopathy ◽

Kappa Light Chain ◽

Immune Mediated

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Association of kappa light chain restriction with peripheral neuropathy among patients with non-IgM monoclonal gammopathy of undetermined significance.

Journal of Clinical Oncology ◽

10.1200/jco.2021.39.15_suppl.e20040 ◽

2021 ◽

Vol 39 (15_suppl) ◽

pp. e20040-e20040

Author(s):

Constantin A. Dasanu ◽

Jaspreet Kaur ◽

Shahaf Tuler ◽

Stephanie Farrell ◽

Steven C. Plaxe

Keyword(s):

Statistical Analysis ◽

Peripheral Neuropathy ◽

Light Chain ◽

Monoclonal Gammopathy ◽

Chronic Inflammatory Demyelinating Polyneuropathy ◽

Axonal Neuropathy ◽

Kappa Light Chain ◽

Related Factors ◽

Study Population ◽

Undetermined Significance

e20040 Background: Monoclonal gammopathy of undetermined significance (MGUS) can be associated with significant neurologic morbidity. Of non-IgM MGUS, types IgG and IgA are most commonly associated with peripheral neuropathy (PN). Methods: With IRB approval, we conducted a retrospective cohort study of consecutive patients with non-IgM type MGUS treated at our institution from 2014-2021. Other conditions potentially causing PN were excluded. Statistical analysis: Descriptive statistics were calculated to characterize the study population, and Relative Risk (RR) of PN was evaluated for selected patient, and disease, related factors. P < 0.05 was defined as statistically significant. Results: During the study period, 94 patients with non-IgM type MGUS were seen and comprised the study population. Twenty-two (23.4%) had evidence of PN. Median age was 74; 82% (18/22 ) were Caucasian; 73% (16/22) were women. 82% (18/22) patients had MGUS type IgG kappa or IgA kappa. We identified only 2 patients with each MGUS kappa light chain (LC) and MGUS IgG lambda. Median M-protein size was 0.11 g/dL, and median free LC value was 6.84 mg/L. Incidence/severity of kidney disease was similar in non-IgM MGUS patients with and without PN (p > 0.05). RR of PN was not found to be significantly different based on race or gender, although there appeared to be a tendency for women to be at higher risk compared to men (RR = 1.98, 95% CI = 0.85 to 4.60, p = 0.114.) Kappa LC restriction was strongly associated with PN (RR = 4.31, 95% CI = 1.58 to 11.78; p = 0.004). Electromyographic (EMG) studies identified 14 patients (64%) with distal symmetric axonal neuropathy (DSAN) and 8 patients (36%) with chronic inflammatory demyelinating polyneuropathy (CIDP). Clinically severe PN was identified in 11 (50%) patients; all were subsequently treated with IVIg therapy. Only 5/11 (45%) patients responded to IVIg, and the responses were only partial and transient. Conclusions: This is the first report, to our knowledge, of a significant association of kappa (as opposed to lambda) LC restriction with PN among patients with non-IgM type MGUS. Further investigation is warranted to explain this finding, elucidate pathophysiology and aid in developing more effective therapeutic options. Pending mechanistic characterization of this association, trials of contemporary agents used to treat other plasma cell disorders may be in order. Final statistical analysis, comparison to published series and significance will be presented.

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