scholarly journals Monoclonal gammopathy of renal significance

2021 ◽  
Author(s):  
Thomas Reiter ◽  
Maja Nackenhorst
Keyword(s):  
B Cell ◽  
Plasma Cell ◽  
Monoclonal Gammopathy ◽  
Cell Clone ◽  
Wide Spectrum ◽  
Organ Damage ◽  
Early Recurrence ◽  
Close Cooperation ◽  
Underlying Disorder ◽  
The Right

SummaryMonoclonal gammopathy of renal significance (MGRS) encompasses a group of kidney disorders in which a monoclonal immunoglobulin secreted by a B cell or plasma cell clone causes renal damage, without meeting hematological criteria for malignancy. The underlying disorder in patients with MGRS is generally consistent with monoclonal gammopathy of undetermined significance (MGUS). Because of the wide spectrum of MGRS-associated diseases, defined through the location and mechanism of renal injury, it is often challenging to establish the right diagnosis. Kidney biopsy must be considered early; hence, close cooperation between hematologist and nephrologists is crucial in diagnosis and treatment from the beginning to prevent irreversible organ damage. Anti B‑cell or plasma-cell clone directed therapy with cytostatic or immunomodulatory agents can save and ameliorate renal function significantly. This is underlined by the fact that, untreated, MGRS-associated disease shows early recurrence in patients after kidney transplantation.

scholarly journals Single Arm, Prospective, Open-Label Phase II Trial to Evaluate the Efficacy of Isatuximab in Patients with Monoclonal Gammopathy of Renal Significance

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 3161-3161 ◽  
Author(s):  
Vikram Premkumar ◽  
Suzanne Lentzsch ◽  
Divaya Bhutani
Keyword(s):  
Multiple Myeloma ◽  
B Cell ◽  
Plasma Cell ◽  
Monoclonal Gammopathy ◽  
Plasma Cells ◽  
Cell Clone ◽  
Advisory Committees ◽  
Renal Response ◽  
Hematologic Response ◽  
Stable Renal Function

Background: Monoclonal gammopathy of renal significance (MGRS) is a monoclonal B cell disorder, not meeting the definition of lymphoma or myeloma, that produces monoclonal proteins which deposit in the kidneys. Permanent renal damage can occur either as a consequence of direct deposition of toxic proteins or by an induced inflammatory response. Due to the low burden of the plasma cell clone, patients do not otherwise qualify for potentially toxic anti-plasma cell treatments and treatment is generally based on consensus opinion. To date there are no clinical trials exploring treatment options. Isatuximab is a chimeric mouse/human IgG1k monoclonal antibody which targets CD38 on both malignant and normal plasma cells and exhibits it antitumor effects primarily by antibody-dependent cellular toxicity. Isatuximab has recently been shown to be an active drug in the treatment of multiple myeloma, with improvements seen in hematologic and renal markers, and has been shown to have manageable toxicity. Given the efficacy of isatuximab in multiple myeloma, we propose a trial evaluating isatuximab monotherapy to treat the small plasma cell clone in MGRS with the hopes of maximizing response and minimizing toxicity. Study Design and Methods: The primary objective of this study is to evaluate efficacy of isatuximab monotherapy in patients with MGRS in order to establish a standard of care treatment for patients with this disease. Adult patients with proteinuria of at least 1 gram in 24 hours and a histopathological diagnosis of MGRS on renal biopsy in the last 24 months will be eligible for the trial. Patients will be excluded if their estimated GFR is below 30 mL/min, they have multiple myeloma, high risk smoldering myeloma, other B cell neoplasm meeting criteria for treatment, concurrent diabetic nephropathy, or require dialysis. Patients will be screened for B cell disorders with bone marrow biopsy and aspirate, serum protein electrophoresis (SPEP) with immunofixation (IFE), 24-hour urine protein electrophoresis (UPEP), free light chain (FLC) testing and screening PET/CT at time of enrollment. Enrolled patients will be administered isatuximab 20 mg/kg IV weekly for 4 weeks and then will receive the same dose every 2 weeks thereafter for a total of 6 months. Patients may be continued on treatment following completion of the 6 months at the discretion of the provider. To reduce the risk of infusion related reactions, patients will receive premedications with corticosteroids, diphenhydramine, H2 blockade and acetaminophen at least 60 minutes prior to infusion. Patients will have repeat SPEP + IFE, 24-hour UPEP + IFE and FLC testing every 4 weeks. There will be an optional repeat kidney biopsy 9-12 months following treatment initiation to assess pathologic response in the kidneys. Statistical Methods: The study will be comprised of 20 patients being treated with isatuximab over a span of 24-30 months. Ten patients will be initiated on the therapy for a period of 6 months. Interim analysis will be done after these patients have completed all the treatment cycles. If 4 out of 10 patients show response in form of improved/stable renal function, the study will proceed to include next 10 patients. If >50% of the first group of 10 patients show doubling of creatinine while on therapy, that would be considered as an indication to discontinue the therapy and the study due to drug toxicity. Endpoints: The primary endpoint will be efficacy as measured by renal response and hematologic response. Renal response will be measured by assessing the amount of proteinuria in a 24 hour urine sample. A sustained reduction in proteinuria by 30% from the patient's baseline amount of proteinuria with stable renal function (serum eGFR within 20% of baseline) will be considered a positive renal response. Hematologic response will be quantified per the 2016 International Myeloma Working Group (IMWG) uniform response criteria for multiple myeloma. An important secondary endpoint will be safety and will be analyzed from all patients who receive any study drug. Adverse events will be characterized and graded according to the National Cancer Institute Common Terminology Criteria for Adverse Events (CTCAE) version 5.0. Other endpoints include time to dialysis and rate of minimal residual disease (MRD) negativity. Disclosures Lentzsch: Caelum Biosciences: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Bayer: Consultancy; Janssen: Consultancy; Takeda: Consultancy; BMS: Consultancy; Proclara: Consultancy; Abbvie: Consultancy; Clinical Care Options: Speakers Bureau; Sanofi: Consultancy, Research Funding; Multiple Myeloma Research Foundation: Honoraria; International Myeloma Foundation: Honoraria; Karyopharm: Research Funding; Columbia University: Patents & Royalties: 11-1F4mAb as anti-amyloid strategy. Bhutani:Sanofi: Membership on an entity's Board of Directors or advisory committees. OffLabel Disclosure: Our trial will be evaluating the efficacy of targeting CD38 on plasma cells with isatuximab in patients with monoclonal gammopathy of renal significance (MGRS). We will evaluate the effects of this drug on 24 hour proteinuria and hematologic response.

scholarly journals Differential diagnosis of monoclonal gammopathy of undetermined significance

Hematology ◽  
2012 ◽  
Vol 2012 (1) ◽  
pp. 595-603 ◽  
Author(s):  
Giampaolo Merlini ◽  
Giovanni Palladini
Keyword(s):  
Differential Diagnosis ◽  
Plasma Cell ◽  
Monoclonal Gammopathy ◽  
Cell Clone ◽  
Organ Damage ◽  
Organ Injury ◽  
Al Amyloidosis ◽  
Monoclonal Protein ◽  
Undetermined Significance

Abstract Monoclonal gammopathy of undetermined significance (MGUS) is an asymptomatic plasma cell disorder occurring in 4.2% of adults > 50 years of age, which can progress into symptomatic diseases either through proliferation of the plasma cell clone, giving rise to multiple myeloma and other lymphoplasmacellular neoplasms, or through organ damage caused by the monoclonal protein, as seen in light-chain amyloidosis and related conditions. Differential diagnosis of asymptomatic and symptomatic monoclonal gammopathies is the determinant for starting therapy. The criteria for determining end-organ damage should include markers of organ injury caused by the monoclonal protein. Patient assessment and optimal follow-up are now performed using risk stratification models that should also take into account the risk of developing AL amyloidosis. Patients with low-risk MGUS (approximately 40% of all MGUS patients) need limited assessment and very infrequent follow-up. The ongoing development of novel molecular biomarkers and advanced imaging techniques will improve the identification of high-risk patients who may benefit from early therapeutic intervention through innovative clinical trials.

Monoclonal gammopathy of clinical significance: a novel concept with therapeutic implications

Blood ◽  
2018 ◽  
Vol 132 (14) ◽  
pp. 1478-1485 ◽  
Author(s):  
Jean-Paul Fermand ◽  
Frank Bridoux ◽  
Angela Dispenzieri ◽  
Arnaud Jaccard ◽  
Robert A. Kyle ◽  
...  
Keyword(s):  
B Cell ◽  
Clinical Significance ◽  
Monoclonal Gammopathy ◽  
Tissue Injury ◽  
Cell Clone ◽  
Early Recognition ◽  
The Elderly ◽  
Organ Damage ◽  
Therapeutic Implications ◽  
Novel Concept

Abstract Monoclonal gammopathy is a common condition, particularly in the elderly. It can indicate symptomatic multiple myeloma or another overt malignant lymphoid disorder requiring immediate chemotherapy. More frequently, it results from a small and/or quiescent secreting B-cell clone, is completely asymptomatic, and requires regular monitoring only, defining a monoclonal gammopathy of unknown significance (MGUS). Sometimes, although quiescent and not requiring any treatment per se, the clone is associated with potentially severe organ damage due to the toxicity of the monoclonal immunoglobulin or to other mechanisms. The latter situation is increasingly observed but still poorly recognized and frequently undertreated, although it often requires rapid specific intervention to preserve involved organ function. To improve early recognition and management of these small B-cell clone–related disorders, we propose to introduce the concept of monoclonal gammopathy of clinical significance (MGCS). This report identifies the spectrum of MGCSs that are classified according to mechanisms of tissue injury. It highlights the diversity of these disorders for which diagnosis and treatment are often challenging in clinical practice and require a multidisciplinary approach. Principles of management, including main diagnostic and therapeutic procedures, are also described. Importantly, efficient control of the underlying B-cell clone usually results in organ improvement. Currently, it relies mainly on chemotherapy and other anti–B-cell/plasma cell agents, which should aim at rapidly producing the best hematological response.

scholarly journals A Prospective Study and Identification of Genomewide Association Markers of Familial Predisposition to Plasma Cell Dyscrasias

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 8-8
Author(s):  
Adam S Sperling ◽  
Rebecca Georgakopoulou ◽  
Mehmet Kemal Samur ◽  
Christine Ivy Liacos ◽  
Brittany E Sandoval ◽  
...  
Keyword(s):  
Genetic Analysis ◽  
B Cell ◽  
Board Of Directors ◽  
Plasma Cell ◽  
Monoclonal Gammopathy ◽  
Research Funding ◽  
Advisory Committees ◽  
Familial Predisposition ◽  
Plasma Cell Dyscrasias ◽  
Second Degree

Introduction: An increased inherited risk for the development of plasma cell dyscrasias (PCDs) has long been suspected, however to date, only a limited number of potential genomic risk loci have been described. To characterize the inherited risk and facilitate identification of additional risk loci it is important to combine detailed pedigrees with extensive genetic analysis. To identify familial PCDs we initiated a prospective study with active recruitment of a large cohort of patients with PCDs and active screening of their relatives combined with tissue banking and subsequent genetic analysis. Methods: All patients in the Department of Clinical Therapeutics diagnosed with PCDs between January 2017 and January 2019, were offered enrollment in the study. Following informed consent, 1st and 2nd degree relatives over the age of 30 were eligible for screening. A detailed family pedigree was created for each index case with special focus on family history of PCDs, B-cell lymphomas, or other hematologic or solid malignancies. As a control, subjects' spouses were also screened. Screening included serum protein electrophoresis with immunofixation. In families where an additional member was identified with a PCD or B-cell malignancy, peripheral blood was collected from consenting family members over the age of 18 for further genetic analysis. Samples from affected individuals were profiled using whole genome sequencing (WGS) and unaffected individuals were genotyped using Axiom Arrays. Data were analyzed using Axion Array Suite and plink and GATK toolkit with BWA. Results: Of 1,084 patients screened for participation in the study; 752 had multiple myeloma (MM), 77 had smoldering MM, 81 a monoclonal gammopathy of undetermined significance, 93 Waldenström's Macroglobulinemia and 81 had AL amyloidosis. 176 (16.2%) patients refused to participate in the study, while 44 (4.1%) patients were ineligible for further screening due to the absence of a living first- or second-degree relative. The median number of screened first or second-degree relatives per index patient was 3 (range 1 to 10). The median age of index cases was 65 years, offspring was 37 years, second-degree relatives was 65 years, and spouses was 65 years. The incidence of a PCD among second-degree relatives was 4.5%, while it was 0.6% among offspring. As a control group, the incidence of PCDs among spouses was 2.6%. Overall at least one additional member (beyond the index patient) with a monoclonal gammopathy was detected in 98 families (11.3%). In 57 families (6.6%) there was a positive history of at least one additional first- or second-degree relative with a PCD or B-cell malignancy. In addition, 41 new cases of monoclonal gammopathy (4.7%) were identified through the screening process associated with this study. To identify genetic loci that could be associated with a predisposition to development of PCDs, genetic analysis was performed on the most heavily affected 18 families, those with at least three affected members or with early onset disease (i.e. PCD diagnosed before age 50). We have evaluated 838,750 SNPs from 103 samples from 18 families. 30 samples were from affected members and 73 from unaffected members. We found eight SNPs (rs13233413, rs11648113, rs59444635, rs148480125, rs113556240, rs11547122, rs671880, rs4726610) that are significantly enriched in affected members with a p-value below the suggestive cut-off of <1e-5. The top candidate was in the untranslated region (UTR) of TSPAN33, a marker of activated and malignant B-cells. We did not detect any significant enrichment in germline mutations in previously reported genes associated with familial PCD risk such as KDM1a, KRAS or DIS3. Functional annotation of the 8 SNPs identified here showed that rs148480125, located in the promoter region of the apoptosis regulator SIVA1, is predicted to impact the allele specific expression level. Further validation work is ongoing. Conclusions: Our active prospective screening approach to identify familial predisposition to PCDs revealed that 11.3% of patients had families with at least one additional affected member and some families had a substantially higher incidence of PCDs with earlier onset. Study of these high-risk families have identified genomewide association markers which in future may help us define familial predisposition to plasma cell dyscrasias. Disclosures Gavriatopoulou: Karyopharm: Consultancy, Honoraria; Genesis Pharma: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Takeda: Consultancy, Honoraria; Amgen: Consultancy, Honoraria. Terpos:Amgen: Honoraria, Research Funding; Genesis pharma SA: Honoraria, Other: travel expenses , Research Funding; Janssen: Honoraria, Research Funding; Takeda: Honoraria, Other: travel expenses , Research Funding; Celgene: Honoraria; Sanofi: Honoraria; BMS: Honoraria. Kastritis:Amgen: Consultancy, Honoraria, Research Funding; Janssen: Consultancy, Honoraria, Research Funding; Takeda: Consultancy, Honoraria; Pfizer: Consultancy, Honoraria; Genesis Pharma: Consultancy, Honoraria. Munshi:Janssen: Consultancy; OncoPep: Consultancy, Current equity holder in private company, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties; BMS: Consultancy; Legend: Consultancy; Amgen: Consultancy; AbbVie: Consultancy; Karyopharm: Consultancy; Takeda: Consultancy; C4: Current equity holder in private company; Adaptive: Consultancy. Dimopoulos:Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Personal fees, Research Funding, Speakers Bureau; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Personal fees, Speakers Bureau; BMS: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Personal fees; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Personal fees, Research Funding, Speakers Bureau; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Personal fees, Research Funding, Speakers Bureau.

scholarly journals An Unusual Case of Acquired Angioedema and Monoclonal Gammopathy of Renal Significance in a Middle-Aged Caucasian Female

2020 ◽  
Vol 8 ◽  
pp. 232470962091209 ◽  
Author(s):  
Sasmit Roy ◽  
Venu Madhav Konala ◽  
Thurein Kyaw ◽  
Sandipan Chakraborty ◽  
Srikanth Naramala ◽  
...  
Keyword(s):  
Acute Kidney Injury ◽  
B Cell ◽  
Monoclonal Gammopathy ◽  
Cell Clone ◽  
Kidney Injury ◽  
Caucasian Woman ◽  
Acquired Angioedema ◽  
Systemic Involvement ◽  
Kidney Involvement ◽  
Esterase Inhibitor

Acquired angioedema due to deficiency of C1 esterase inhibitor is also called acquired angioedema and is abbreviated as C1INH-AAE. It is a rare syndrome of recurrent episodes of angioedema, without urticaria, and in some patients, it is associated with B-cell lymphoproliferative disorders. Kidney involvement is rare in this condition. The monoclonal immunoglobulin secreted by a nonmalignant or premalignant B-cell or plasma cell clone, causing renal damage that represents a group of disorders which are termed as monoclonal gammopathy of renal significance (MGRS). In this article, we report a rare case of acquired C1 esterase deficiency angioedema and acute kidney injury with renal biopsy-proven MGRS. We present a 64-year-old Caucasian woman who presented with 2 weeks of recurring urticaria and new onset of acute kidney injury. She was diagnosed with monoclonal gammopathy–associated proliferative glomerulopathy through kidney biopsy, and serological workup came back positive for C1 esterase deficiency, implying acquired angioedema. Acquired angioedema is a rare disease with systemic involvement. Recurrent allergic manifestations and acute kidney injury should prompt MGRS as a differential.

scholarly journals Ig VH gene mutational patterns indicate different tumor cell status in human myeloma and monoclonal gammopathy of undetermined significance

Blood ◽  
1996 ◽  
Vol 87 (2) ◽  
pp. 746-755 ◽  
Author(s):  
SS Sahota ◽  
R Leo ◽  
TJ Hamblin ◽  
FK Stevenson
Keyword(s):  
Multiple Myeloma ◽  
Tumor Cell ◽  
Plasma Cell ◽  
Monoclonal Gammopathy ◽  
Somatic Hypermutation ◽  
Wide Spectrum ◽  
Malignant Potential ◽  
Gene Sequences ◽  
Vh Gene ◽  
Undetermined Significance

Plasma cell tumors display a wide spectrum of clinical progression, ranging from aggressive multiple myeloma to a benign form known as monoclonal gammopathy of undetermined significance (MGUS), which requires no treatment. Because both diseases involve mature Ig- secreting plasma cells, the reason for this variation in malignant behavior is unclear. However, assessment of malignant potential is desirable for choice of treatment protocols. Ig variable (VH) gene sequences analysis has previously shown the tumor cell of multiple myeloma to be postfollicular, with mutated homogeneous clonal sequences indicating no continuing exposure to the somatic hypermutation mechanism, and this was confirmed in 7 of 7 patients. Comparison of the VH gene sequences in the monoclonal cells in MGUS yielded a different result, with 3 of 7 patients demonstrating mutated heterogeneous sequences consistent with the tumor cells remaining under the influence of the mutator. In 1 of 3 of these patients, an IgM-positive precursor cell was identified that expressed heterogeneous VH sequences similar to those of the isotype-switched plasma cell. These results indicate that the clonal cells in MGUS differ from those in myeloma and suggest that the difference may reflect malignant potential.

My Patient with Monoclonal Gammopathy of Undetermined Significance has a Kidney Problem

2017 ◽  
Vol 1 (1) ◽  
pp. 18-23 ◽  
Author(s):  
Nelson Leung
Keyword(s):  
Kidney Disease ◽  
B Cell ◽  
Monoclonal Gammopathy ◽  
Lymphoproliferative Disorder ◽  
Kidney Diseases ◽  
Organ Damage ◽  
Renal Diseases ◽  
Premalignant Condition ◽  
Definition Of ◽  
Undetermined Significance

Monoclonal gammopathy of undetermined significance (MGUS) is a premalignant condition signifying the presence of a B-cell lymphoproliferative disorder. By connotation, it should not meet the definition of multiple myeloma, Waldenström macroglobulinemia, or lymphoma. In addition, it cannot be responsible for any end-organ damage. Similar to polyclonal immunoglobulins (Ig), monoclonal gammopathy has been increasingly recognized as an important cause of kidney disease. The recent introduction of the term “monoclonal gammopathy of renal significance” (MGRS) highlights this importance. MGRS is similar to MGUS in which the B-cell lymphoproliferative disorder has not reached a state considered to be malignant, but differentiates itself by the presence of a monoclonal gammopathy related kidney disease. This distinction is important since it separates MGRS, which is not benign, from the MGUS condition, which is benign. It also allows for a better classification of kidney diseases caused by monoclonal gammopathies. There are many renal diseases and lesions that have been identified to be secondary to MGRS. In addition, MGRS-associated renal diseases can mimic polyclonal Ig mediated kidney diseases. Kidney biopsy with immunofluorescence is the key for diagnosing MGRS-related kidney diseases. Once the diagnosis is made, a specific evaluation is needed for the diagnosis and treatment of MGRS-related kidney diseases that differs from the polyclonal Ig counterparts.

scholarly journals Treatment of B-cell disorder improves renal outcome of patients with monoclonal gammopathy–associated C3 glomerulopathy

Blood ◽  
2017 ◽  
Vol 129 (11) ◽  
pp. 1437-1447 ◽  
Author(s):  
Sophie Chauvet ◽  
Véronique Frémeaux-Bacchi ◽  
Florent Petitprez ◽  
Alexandre Karras ◽  
Laurent Daniel ◽  
...  
Keyword(s):  
B Cell ◽  
Monoclonal Gammopathy ◽  
Cell Clone ◽  
Specific Treatment ◽  
Renal Outcome ◽  
C3 Glomerulopathy ◽  
Renal Survival ◽  
Key Points ◽  
Cell Disorder

Key Points Monoclonal gammopathy is associated with C3 glomerulopathy. Specific treatment of the underlying B-cell clone improves renal survival.

scholarly journals Follow-up Care of Monoclonal Gammopathy of Undetermined Significance: A Guide for Primary Care Physicians

2021 ◽  
Vol 8 (5) ◽  
Author(s):  
Hammad Z ◽  
◽  
Hernandez E ◽  
Tate S ◽  
◽  
...  
Keyword(s):  
Plasma Cell ◽  
Primary Care Physicians ◽  
Monoclonal Gammopathy ◽  
Plasma Cells ◽  
Organ Damage ◽  
M Protein ◽  
Bone Lesions ◽  
Al Amyloidosis ◽  
End Organ Damage ◽  
Undetermined Significance

Monoclonal Gammopathy of Undetermined Significance (MGUS) is a condition in which M protein, an abnormal monoclonal immunoglobulin, is present in the blood at a nonmalignant level. Specifically, it is defined by: blood serum M protein concentration <3 g/dL (<30 g/L), <10% plasma cells in the bone marrow, and no evidence of end organ damage [1,2]. Evidence of end organ damage includes hypercalcemia, renal insufficiency, anemia, and bone lesions. These are indicative of MGUS progression and which can be attributed to the monoclonal plasma cell proliferative process [3]. MGUS occurs in 3% of the general population older than 50 years. Incidence increases with age and varies with sex with higher rates observered in males than females [1,4]. MGUS is the most common plasma cell disorder, with 60% of patients that present to the Mayo Clinic with a monoclonal gammopathy being diagnosed with MGUS [3]. While it is typically an asymptomatic condition, it is premalignant disorder to other monoclonal gammopathies. Multiple Myeloma (MM) is almost always preceded by MGUS and the majority of patients will have detectable levels of M protein for at least 5 years prior to MM diagnosis [5,6]. MGUS also precedes immunoglobulin light chain (AL) amyloidosis and Waldenstrom Macroglobulinemia (WM) and tends to progress to disorders at a fixed but unrelenting rate of 1% per year [4].

scholarly journals Crystalline deposits in the cornea and various areas of the kidney as symptoms of an underlying monoclonal gammopathy: a case report

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
C. Lindemann ◽  
P. Enders ◽  
P. T. Brinkkoetter ◽  
L. A. Völker
Keyword(s):  
Plasma Cell ◽  
Light Chain ◽  
Monoclonal Gammopathy ◽  
Wide Spectrum ◽  
Diagnostic Testing ◽  
Percutaneous Biopsy ◽  
Light Chains ◽  
Crystalline Deposits ◽  
Light Chain Proximal Tubulopathy ◽  
Monoclonal Proteins

Abstract Background Plasma cell dyscrasias (PCD) are characterized by an abnormal production of intact monoclonal immunoglobulins or parts such as heavy or light chains. In most cases, the monoclonal protein (also termed paraprotein) is produced by a clonal plasma cell population. The production of monoclonal proteins can result in deposits of various types and localization depending on the type, amount, and electrochemical properties of the paraprotein. One histopathologic presentation, albeit rare, are crystalline deposits. They can form in various organs and hence cause a wide spectrum of symptoms. Case presentation A 49-year-old man presented to the emergency department with eyestrain and foreign body sensation after overhead drilling. Examination of the eyes revealed crystalline deposits in the cornea of both eyes. After additional diagnostic testing, deposits were attributed to free light chains. Monoclonal gammopathy of undetermined significance (MGUS) was diagnosed according to serum electrophoresis and immunofixation. Four years later, new onset of proteinuria was detected. A percutaneous biopsy of the kidney showed severe light chain podocytopathy with secondary focal segmental glomerulosclerosis (FSGS) and light chain proximal tubulopathy (LCPT). In these lesions, crystalline deposits identical to the corneal deposits were found in ultrastructural and immunofluorescent analysis. The patient was diagnosed with monoclonal gammopathy of renal significance (MGRS), and a plasma cell directed therapy was initiated. Conclusions PCD can present with a wide array of symptoms and are notoriously difficult to diagnose. Extrarenal manifestations such as crystalline deposits in the cornea are one possible manifestation. The case presented herein emphasizes the notion that extrarenal paraprotein deposits warrant a thorough search for the underlying clonal disease.

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