Monoclonal gammopathy of renal significance: Early diagnosis is key / Gammapatía monoclonal de significado renal: la clave es el diagnóstico precoz

Monoclonal gammopathy of renal significance is a clinical–pathological entity grouping renal disorders secondary to the secretion of a monoclonal immunoglobulin synthesized by a B-cell-derived clone and/or plasma cells in a patient with no diagnostic criteria for multiple myeloma. This term applies to a concept recently introduced owing to the need to differentiate this entity from monoclonal gammopathy of undetermined significance, given the negative prognostic impact of its high morbidity and mortality resulting from both renal and systemic involvement, occasionally even progressing to advanced chronic kidney disease. The renal damage occurs via both direct pathogenic mechanisms, with the deposition of the monoclonal protein in different renal structures, as well as indirect mechanisms, acting as an autoantibody provoking dysregulation of the alternative complement pathway. The detection of this monoclonal protein and an early hematologic study are essential, as is the need for a kidney biopsy to establish the associated nephropathological diagnosis. Consequently, this then leads to the start of specific hematologic treatment to detain the production of the monoclonal protein and minimize renal and systemic injury. (AU)

La gammapatía monoclonal de significado renal es una entidad clínico-patológica que agrupa los trastornos renales secundarios a la secreción de una inmunoglobulina monoclonal sintetizada por un clon derivado de células B y/o células plasmáticas en un paciente sin criterios de diagnóstico de mieloma múltiple. Este término se aplica a un concepto introducido recientemente debido a la necesidad de diferenciar esta entidad de la gammapatía monoclonal de significado incierto, teniendo en cuenta el impacto pronóstico negativo de su alta morbilidad y mortalidad a causa de la afectación tanto renal como sistémica, llegando en ocasiones a progresar a una enfermedad renal crónica avanzada. El daño renal se produce tanto por mecanismos patogénicos directos, con el depósito de la proteína monoclonal en diferentes estructuras renales, como por mecanismos indirectos, actuando como un autoanticuerpo que provoca la desregulación de la vía alternativa del complemento. La detección de esta proteína monoclonal y un estudio hematológico precoz son imprescindibles, así como la necesidad de una biopsia renal para establecer el diagnóstico nefropatológico asociado. En consecuencia, esto lleva al inicio de un tratamiento hematológico específico para detener la síntesis de la proteína monoclonal y minimizar la lesión renal y sistémica. (AU)

The impact of COVID-19 in the management of AL amyloidosis and Immunoglobulin Deposition Disease: A single-center experience.

INTRODUCTION: Patients with AL amyloidosis and immunoglobulin deposition diseases (IDD) are vulnerable during the COVID-19 pandemic due to the immune compromise from the plasma cell disorder and therapy-related immune defects. We describe a local experience in providing care for patients with AL amyloidosis and IDD. METHOD: Patient treatment and disease status since the beginning of the pandemic on March 11, 2020, as declared by WHO, were collected and analyzed. RESULTS: Ninety-six patients with AL amyloidosis and IDD were included. Four patients with IDD and 22 patients with systemic AL amyloidosis were receiving treatment during the pandemic. Since the pandemic, patients' treatments were discontinued if they achieved VGPR or better postinduction. Seven patients discontinued all treatment after achieving VGPR, and others required treatment modifications. 28 patients have been tested for COVID-19, and all tests have been negative. Three patients died since the pandemic, two from organ complications of systemic AL amyloidosis and one from an unrelated cause. CONCLUSION: The management of AL amyloidosis and IDD must be individualized on the clinical characteristics, centers' access to care under the pandemic restrictions, and the epidemiological aspects of the outbreak.

Monoclonal gammopathy and serum immunoglobulin levels as prognostic factors in chronic lymphocytic leukaemia.

The relationship between chronic lymphocytic leukaemia (CLL) and qualitative/quantitative gammaglobulin abnormalities is well established. Nevertheless, in order to better understand this kind of connection, we examined 1505 patients with CLL and divided them into four subgroups on the basis of immunoglobulin (Ig) aberrations at diagnosis. A total of 73 (4·8%), 149 (10%), 200 (13·2%) and 1083 (72%) patients were identified with IgM monoclonal gammopathy (IgM/CLL), IgG monoclonal gammopathy (IgG/CLL), hypogammaglobulinaemia (hypo-γ) and normal Ig levels (γ-normal) respectively. IgM paraprotein was significantly associated with a more advanced Binet/Rai stage and del(17p)/TP53 mutation, while IgG abnormalities correlated with a higher occurrence of trisomy 12. Patients with any type of Ig abnormality had shorter treatment-free survival (TFS) but no significant impact affecting overall survival (OS) compared to those with normal Ig levels.

Immunoglobulin light-chain toxicity in a mouse model of monoclonal immunoglobulin light-chain deposition disease.

Light chain (LC) deposition disease (LCDD) is a rare disorder characterized by glomerular and peritubular amorphous deposits of a monoclonal immunoglobulin LC, leading to nodular glomerulosclerosis and nephrotic syndrome. We developed a transgenic model using site-directed insertion of the variable domain of a pathogenic human LC gene into the mouse immunoglobulin κ locus, ensuring its production by all plasma cells (PCs). High free LC levels were achieved after backcrossing with mice presenting increased PC differentiation and no immunoglobulin heavy chain production. Our mouse model recapitulates the characteristic features of LCDD, including progressive glomerulosclerosis, nephrotic-range proteinuria, and finally kidney failure. The variable domain of the LC bears alone the structural properties involved in its pathogenicity. RNA sequencing conducted on PCs demonstrated that LCDD LC induces endoplasmic reticulum stress, likely accounting for the high efficiency of proteasome inhibitor-based therapy. Accordingly, reduction of circulating pathogenic LC was efficiently achieved and not only preserved renal function but also partially reversed kidney lesions. Finally, transcriptome analysis of presclerotic glomeruli revealed that proliferation and extracellular matrix remodeling represented the first steps of glomerulosclerosis, paving the way for future therapeutic strategies in LCDD and other kidney diseases featuring diffuse glomerulosclerosis, particularly diabetic nephropathy.

Clinicopathologic Assessment of Monoclonal Immunoglobulin-associated Renal Disease in the Kidney Allograft: A Retrospective Study and Review of the Literature.

BACKGROUND: Monoclonal immunoglobulin (MIg)-associated renal disease (MIgARD) comprises a group of disorders caused by direct deposition of paraproteins in the kidney. Allograft MIgARD is infrequently encountered and poorly characterized. METHODS: First, we assessed our allograft biopsies diagnosed with MIgARD between 2007 and 2018. The cohort included the following 26 patients: proliferative glomerulonephritis with MIg deposits (PGNMID) (n = 13), AL amyloidosis (n = 5), light chain deposition disease (n = 5), light chain proximal tubulopathy (n = 2), and light chain cast nephropathy (n = 1). Second, we conducted a literature review to evaluate the rare non-PGNMID entities. We identified 20 studies describing 29 patients that were added to our cohort (total n = 42). RESULTS: Part 1: Patients' median age was 55 years; 31% were women, and 19% were blacks. Twelve patients (46%) lost their grafts at a median of 8 months after diagnosis. Compared to non-PGNMID, PGNMID patients had lower frequency of detectable paraproteins (31% versus 92%, P = 0.004) and hematologic neoplasms (23% versus 77%, P = 0.02). Within PGNMID group, 6 patients changed their apparent immunofluorescence phenotype between monotypic and polytypic, while all 3 patients with hematologic neoplasms had substructure on electron microscopy. Part 2: Whereas light chain cast nephropathy occurred the earliest and had the worst graft survival, AL amyloidosis occurred the latest and had the best graft survival. CONCLUSIONS: MIgARD in the kidney allograft is associated with poor prognosis. While posttransplant PGNMID can change its apparent clonality by immunofluorescence supporting oligoclonal immune responses, the presence of deposit substructure is an important indicator of underlying hematologic neoplasm. Non-PGNMID are often associated with hematologic neoplasms and varied prognosis.

Immunoglobulin abnormalities in 1677 solid organ transplant recipients. Implications for posttransplantation follow-up.

BACKGROUND: Posttransplant lymphoproliferative disorder (PTLD) is a severe complication of solid organ transplantation (SOT). However, there is no consensus on PTLD screening methods. Gammopathies (GP), which occur in 10-25% of SOT recipients, have been linked to subsequent development of PTLD. Therefore, GP detection methods, such as serum protein electrophoresis (SPE), serum protein immunofixation (SIFE), urine protein immunofixation (UIFE) and the quantitative measurement of serum free light chains (SFLC) are candidate methods for PTLD screening. OBJECTIVE: We aimed to assess the frequency of PTLD and GP, association of GP with subsequent PTLD, allograft loss or death and the diagnostic performance of SPE/SIFE in PTLD screening. The main objective was to explore, whether GP detection methods can be used to enhance the efficiency of PTLD screening and to formulate a concise algorithm for posttransplantation (post-Tx) follow-up. METHODS: We performed a cohort study on 1677 SOT recipients with SPE/SIFE data who underwent kidney, liver, heart, pancreas, Langerhans islets or multiple organ transplantation at the Institute of Clinical and Experimental Medicine between 1966 and 2015. The median (IQR) of follow-up time was 8.0 (4.0-12.0) years. RESULTS: The frequencies of PTLD and GP in SOT recipients were 2.8% and 6.4%, respectively. The frequencies of transient GP, GP of undetermined significance and malignant GP were 33%, 63% and 4% respectively. The median time between SOT and GP detection was 2.0 (interquartile range 1.0-7.0) years. GP was associated with a significantly higher risk of PTLD, allograft loss and death, with hazard ratios (95% confidence intervals) of a 6.06 (2.51-14.64), 2.61 (1.49-4.6) and 1.99 (1.2-3.3), respectively. Additionally, GP was associated with 2.98-fold increased risk of allograft loss in kidney transplant patients. SPE diagnostic sensitivity and specificity for PTLD were 14.8% and 93.9%, respectively. PTLD was diagnosed more often and earlier if SPE/SIFE was included in the post-Tx follow-up. CONCLUSIONS: GP after SOT is associated with a high risk of PTLD, allograft loss and poor survival. The combination of SPE, SIFE, SFLC and UIFE is optimal for GP detection. These methods aid in identifying patients who are at risk for PTLD or allograft damage and should be included in regular post-Tx follow-up.

Impact of prior diagnosis of monoclonal gammopathy on outcomes in newly diagnosed multiple myeloma.

Multiple myeloma (MM) is consistently preceded by monoclonal gammopathy of undetermined significance (MGUS), smoldering myeloma (SMM), or solitary plasmacytoma (SPC). There is a lack of data regarding impact of these pre-existing monoclonal gammopathies (MGs) on MM outcomes. Patients with prior diagnosis of MGUS, SMM, or PC from 1973 to 2015 (cases) were identified from our institution's database and compared to those without a known MG (controls). The primary outcome of interest was overall survival (OS). Multivariate analysis was performed to ascertain factors impacting all-cause mortality. We identified 774 patients with a prior diagnosis of MGUS, SMM or SPC (cases) and a control population (1:2) matched for the year of diagnosis (n = 1548). After a median follow-up of 81 months, the cases showed a longer median OS than the controls (71 months vs. 56 months). The improved OS was limited to those with a known prior diagnosis of SMM (80 months) and SPC (95 months), compared to MGUS (60 months). Multivariable analysis revealed that MM patients with known prior MG had less overall mortality than those without, and this was limited to prior SMM/SPC group (HR 0.68, 95% CI: 0.50-0.93), as compared to the MGUS group (HR 0.83, 95% CI: 0.66-1.05).

The serum heavy/light chain immunoassay: A valuable tool for sensitive paraprotein assessment, risk, and disease monitoring in monoclonal gammopathies.

OBJECTIVE: The heavy/light chain (HLC)-immunoassay quantifies light chain types of each immunoglobulin class in patients with monoclonal gammopathies. METHODS: We assessed 147 consecutive patients with different forms and stages of plasma cell dyscrasias (PCD) who received standard tests (serum and urine protein electrophoresis [SPEP, UPEP], immunofixation [IFE], serum-free light chain [SFLC]), and HLC-immunoassay. Patients with multiple myeloma (MM, n = 102), smoldering MM (SMM, n = 5), monoclonal gammopathy of undetermined significance (MGUS, n = 28), and Waldenström's macroglobulinemia (WM, n = 12) were included. RESULTS: We verified a significant correlation between HLC- and standard monoclonal protein (mp)-parameters, and HLC-increases with higher disease stage and unfavorable remission status. In patients with difficult to quantify mp, more abnormal HLC- than SPEP-, immunoglobulin-, or SFLC-results were found. In WM, a pathological HLC κ/λ-ratio and M-component were observed in 95% and 58%, respectively. In 21/28 MGUS and 5/5 SMM patients, HLC κ/λ-ratios were abnormal. Testing different HLC cutoffs, patients with extreme HLC values showed impaired progression-free survival (PFS). CONCLUSIONS: Despite the fact that different PCD patients were included, the assessment of the HLC-immunoassay in MGUS, SMM, MM, and WM, our comparison with standard mp-assays, and relevant PFS differences may excite future applications, which should be confirmed in prospective multicenter trials.

Intravenous Immunoglobulins Improve Survival in Monoclonal Gammopathy-Associated Systemic Capillary-Leak Syndrome.

BACKGROUND: Monoclonal gammopathy-associated systemic capillary-leak syndrome, also known as Clarkson disease, is a rare condition characterized by recurrent life-threatening episodes of capillary hyperpermeability in the context of a monoclonal gammopathy. This study was conducted to better describe the clinical characteristics, natural history, and long-term outcome of monoclonal gammopathy-associated systemic capillary-leak syndrome. METHODS: We conducted a cohort analysis of all patients included in the European Clarkson disease (EurêClark) registry between January 1997 and March 2016. From diagnosis to last follow-up, studied outcomes (eg, the frequency and severity of attacks, death, and evolution toward multiple myeloma) and the type of preventive treatments administered were monitored every 6 months. RESULTS: Sixty-nine patients (M/F sex ratio 1:1; mean ± SD age at disease onset 52 ± 12 years) were included in the study. All patients had monoclonal gammopathy of immunoglobulin G type, with kappa light chains in 47 (68%). Median (interquartile range) follow-up duration was 5.1 (2.5-9.7) years. Twenty-four patients (35%) died after 3.3 (0.9-8) years. Fifty-seven (86%) patients received at least one preventive treatment, including intravenous immunoglobulins (IVIg) n = 48 (73.8%), theophylline n = 22 (33.8%), terbutaline n = 22 (33.8%), and thalidomide n = 5 (7.7%). In the 65 patients with follow-up, 5- and 10-year survival rates were 78% (n = 35) and 69% (n = 17), respectively. Multivariate analysis found preventive treatment with IVIg (hazard ratio 0.27; 95% confidence interval, 0.10-0.70; P = .007) and terbutaline (hazard ratio 0.35; 95% confidence interval, 0.13-0.96; P = .041) to be independent predictors of mortality. CONCLUSIONS: We describe the largest cohort to date of patients with well-defined monoclonal gammopathy-associated systemic capillary-leak syndrome. Preventive treatment with IVIg was the strongest factor associated with survival, suggesting the use of IVIg as the first line in prevention therapy.

Increased fracture risk in plasma cell dyscrasias is associated with poorer overall survival.

Pathological fractures are a common complication of plasma cell dyscrasias (PCD) and are associated with significant morbidity. Routine use of bisphosphonates over the past decade has aimed to reduce the risk of fractures in patients with multiple myeloma, but despite this, fractures continue to represent a significant burden of disease. In this study we report the fracture rate of hospital in-patients with PCD in England. Data from the national registry Hospital Episode Statistics between 2001 and 2015 were used to determine fracture rate and its effect on overall survival. Fracture rates were 17·8 times higher than the general population in the first year after admission with PCD, and remained elevated for up to 10 years after first admission. The increased fracture risk preceded the first admission with PCD and, conversely, the incidence of PCD increased after admission with one or more fractures. Overall survival is improving with PCD, however poorer survival is found in patients with a preceding fracture (Hazard ratio 1·20). Despite widespread bisphosphonate use, fractures remain common in PCD, and are associated with poorer outcomes.

Immunoparesis in IgM gammopathies as a useful biomarker to predict disease progression.

BACKGROUND: The management of IgM monoclonal gammopathies undetermined significance (IgM-MGUS) and Waldenstrom's macroglobulinemia (WM) may be challenging. Modern immunoassays that quantify specific monoclonal heavy and light chain immunoglobulins are promising for their use in these applications. METHODS: Ninety consecutive patients (39 IgM-MGUS, 32 indolent WM [iWM], and 19 WM) seen between January 2007 and March 2014 were analyzed. Heavy/light chain (HLC) and serum free light chains assays (FLC) were determined at diagnosis to study their utility as biomarkers in IgM monoclonal gammopathies. RESULTS: The HLC involved to uninvolved IgM ratios (iHLC/uHLC) showed a progressive increase when going from IgM-MGUS, to iWM and to WM (p=0.002). Furthermore, an iHLC/uHLC>62 identified a group of iWM patients with a shorter time-to-progression (TTP) (108 vs. 133 months, p=0.033). Separate analysis of the involved and uninvolved components showed that only the suppression of the uninvolvedimmunoglobulin was predictive of shorter TTP (HR=3.04, p=0.03) suggesting that it could be the majorcontributor to the prognostic value of the Hevylite assay. Additionally, a multivariate analysis showed that immunosuppression (either classical immunoparesis or Hevylite immunosuppression) was an independent prognostic factor (p=0.016) reinforcing its relevance in the disease mechanism. Finally, monoclonal sFLC levels were highest in WM patients, with 83% presenting values>60 mg/L. CONCLUSIONS: The results suggest that the levels of immunosuppression and/or the iHLC/uHLC ratio of IgM immunoglobulins measured by Hevylite are associated with greater disease activity which significantly impacts in the outcome of WM patients and may also help in the differentiation of IgMMGUS from iWM.

Hematologic and renal improvement of monoclonal immunoglobulin deposition disease after treatment with bortezomib-based regimens.

Monoclonal immunoglobulin deposition disease (MIDD) is characterized by non-organized immunoglobulin-fragments along renal basement membranes with subsequent organ deterioration. Treatment is directed against the immunoglobulin-producing clone. We treated 18 MIDD patients with bortezomib-based regimens (12 received bortezomib-dexamethasone, 6 bortezomib-dexamethasone with cyclophosphamide). Eleven (61%) patients achieved a hematologic response, but only 6 (33.3%) reached to a complete (CR) or very good partial response (VGPR). Regarding renal outcomes 77.8 and 55.6% had ≥30 and ≥50% reduction of proteinuria, respectively, but 33.3% ended up in end-stage renal disease (ESRD). Among patients with CR or VGPR, median eGFR improvement was 7.7 ml/min/1.73 m2 and none progressed to ESRD, but no significant renal recovery was observed in patients achieving a partial response or less, with 50% progressing to dialysis. Pretreatment eGFR seems to influence renal prognosis. Bortezomib-based treatment is considered an effective approach in MIDD and reaching to a deep hematologic response (≥VGPR) conditionally controls further renal declining.

Aberrant p15, p16, p53, and DAPK Gene Methylation in Myelomagenesis: Clinical and Prognostic Implications.

BACKGROUND: Aberrant DNA methylation is considered a crucial mechanism in the pathogenesis of monoclonal gammopathies. We aimed to investigate the contribution of hypermethylation of 4 tumor suppressor genes to the multistep process of myelomagenesis. METHODS: The methylation status of p15, p16, p53, and DAPK genes was evaluated in bone marrow samples from 94 patients at diagnosis: monoclonal gammopathy of uncertain significance (MGUS) (n = 48), smoldering multiple myeloma (SMM) (n = 8) and symptomatic multiple myeloma (MM) (n = 38), and from 8 healthy controls by methylation-specific polymerase chain reaction analysis. RESULTS: Overall, 63% of patients with MM and 39% of patients with MGUS presented at least 1 hypermethylated gene (P < .05). No aberrant methylation was detected in normal bone marrow. The frequency of methylation for individual genes in patients with MGUS, SMM, and MM was p15, 15%, 50%, 21%; p16, 15%, 13%, 32%; p53, 2%, 12,5%, 5%, and DAPK, 19%, 25%, 39%, respectively (P < .05). No correlation was found between aberrant methylation and immunophenotypic markers, cytogenetic features, progression-free survival, and overall survival in patients with MM. CONCLUSIONS: The current study supports a relevant role for p15, p16, and DAPK hypermethylation in the genesis of the plasma cell neoplasm. DAPK hypermethylation also might be an important step in the progression from MGUS to MM.

Outcomes of patients with renal monoclonal immunoglobulin deposition disease.

Recent reports suggest that deep hematologic responses to chemotherapy are associated with improved renal outcomes in monoclonal immunoglobulin deposition disease (MIDD). Here we describe the long term outcomes and identify prognostic factors after first line treatment of the largest reported series of patients with MIDD. Between March 1992 and December 2014, 88 patients with MIDD were seen at Mayo Clinic, MN. Renal responses were defined using criteria used for light chain amyloidosis (AL) or those used by the IMWG. Sixty-one (69%) patients had a GFR < 30 mL/min/1.73 m2 and 16 (18%) were on renal replacement therapy at diagnosis. The interval between albuminuria or elevation in creatinine and MIDD diagnosis was 12 months suggesting a delay in diagnosis. Thirty-seven patients (42%) had at least a hematologic CR/VGPR. Fifty-three (60%) received an autologous stem cell transplant (ASCT) or proteasome inhibitor (PI)-based treatments. Patients receiving ASCT or PI-based therapies were more likely to achieve at least a hematologic CR/VGPR compared to those receiving other therapies: 66% vs 2%, p < 0.0001. Patients that achieved a hematologic CR were more likely to achieve a renal response (53% vs 24%, p = 0.001). Five year overall and renal survival for the entire cohort was 67% and 57%, respectively. In multivariate analyses, a baseline GFR < 20 mL/min/1.73 m2 and a renal response (using AL or IMWG criteria) were independently predictive of progression to dialysis. This study confirms that deep hematologic responses, best achieved with ASCT or PI-based therapies, are a prerequisite to achieving renal responses. Am. J. Hematol. 91:1123-1128, 2016. © 2016 Wiley Periodicals, Inc.

Clinicopathologic features and outcomes of lymphoplasmacytic lymphoma patients with monoclonal IgG or IgA paraprotein expression.

Lymphoplasmacytic lymphoma secreting IgG or IgA (non-IgM LPL) is rarely seen. Systematic studies of the clinical features and treatment outcomes are lacking in these patients. This study evaluated 17 patients with non-IgM LPL. The paraprotein secreted by these tumors was IgA (n=8; 47%) and IgG (n=9; 53%). The median serum level of paraprotein was 2,475 mg/dl (range=747-5260) for IgA and 2580 mg/dl (range=1900-7100) for IgG. The IgA-LPL group was more likely to present with B symptoms, a high beta2-microglobulin level and extramedullary involvement. Compared with patients with Waldenström macroglobulinemia (WM), patients with non-IgM LPL showed similar clinical and pathologic features, but a higher mortality within the first year after diagnosis (p<0.001) and worse overall survival (p=0.024), with no difference in progression-free survival and disease-specific survival. Rituximab alone or rituximab-based therapy was used frequently and was effective as either first-line or salvage therapy.

Natural history and outcome of light chain deposition disease.

Light chain deposition disease (LCDD) is characterized by the deposition of monotypic immunoglobulin light chains in the kidney, resulting in renal dysfunction. Fifty-three patients with biopsy-proven LCDD were prospectively followed at the UK National Amyloidosis Center. Median age at diagnosis was 56 years, and patients were followed for a median of 6.2 years (range, 1.1-14.0 years). Median renal survival from diagnosis by Kaplan-Meier analysis was 5.4 years, and median estimated patient survival was 14.0 years; 64% of patients were alive at censor. Sixty-two percent of patients required dialysis, and median survival from commencement of dialysis was 5.2 years. There was a strong association between hematologic response to chemotherapy and renal outcome, with a mean improvement in glomerular filtration rate (GFR) of 6.1 mL/min/year among those achieving a complete or very good partial hematologic response (VGPR) with chemotherapy, most of whom remained dialysis independent, compared with a mean GFR loss of 6.5 mL/min/year among those achieving only a partial or no hematologic response (P < .009), most of whom developed end-stage renal disease (ESRD; P = .005). Seven patients received a renal transplant, and among those whose underlying clonal disorder was in sustained remission, there was no recurrence of LCDD up to 9.7 years later. This study highlights the need to diagnose and treat LCDD early and to target at least a hematologic VGPR with chemotherapy, even among patients with advanced renal dysfunction, to delay progression to ESRD and prevent recurrence of LCDD in the renal allografts of those who subsequently receive a kidney transplant.

The application of Gadopentate-Dimeneglumin has no impact on progression free and overall survival as well as renal function in patients with monoclonal plasma cell disorders if general precautions are taken.

OBJECTIVES: The current analysis investigated the prognostic significance of gadopentetate dimeglumine on survival and renal function in patients with monoclonal plasma cell disorders. METHODS: In this study 263 patients who had received gadopentetate dimeglumine within a prospective trial investigating dynamic contrast-enhanced magnetic resonance imaging (MRI) were compared with 335 patients who had undergone routine, unenhanced MRI. RESULTS: We found no significant prognostic impact of the application of contrast agent on progression-free survival in patients with either monoclonal gammopathy of undetermined significance, smouldering or symptomatic myeloma and no significant prognostic impact on overall survival in patients with symptomatic myeloma. Since renal impairment is a frequent complication of myeloma, and decreased renal function is associated with a higher risk of complications in patients receiving contrast agents, we evaluated the impact of contrast agent on renal function after 1 year. In the present analysis the only significant adverse impact on kidney function occurred in symptomatic myeloma patients who already had impaired renal parameters at baseline. Here, the renal function did not recover during therapy, whereas it did so in patients with normal or only slightly impaired renal function. CONCLUSION: If general recommendations are adhered to, gadopentetate dimeglumine can be safely applied in patients with monoclonal plasma cell disease.

Immunoglobulin light chain amyloidosis is diagnosed late in patients with preexisting plasma cell dyscrasias.

AL amyloidosis (AL) is rare and frequently remains undiagnosed until organ function is compromised, even among patients with known pre-existing untreated plasma cell dyscrasias (PCD). We identified 168 patients with AL amyloidosis who had a prior untreated PCD. The earliest symptom or sign (s/s) was defined as the first symptom reported by the patient that could be attributed to organ dysfunction caused by AL. The interval from the time of development of s/s to the establishment of diagnosis of AL (Interval-SA) was calculated. PCD diagnosis preceded recorded onset of s/s in 75% (114/152) of patients, with a median interval-SA for this group of 10 months. PCD was diagnosed after s/s in 25% (38/152) of patients, with a median interval-SA of 20 months. Overall survival (OS) from diagnosis of AL was not different between the two groups. AL amyloidosis patients with an identified pre-existing PCD had less advanced cardiac disease at AL diagnosis when compared to a control group of AL patients without pre-identified PCD. Long-term OS was not significantly superior among patients with a pre-identified PCD. In patients with "asymptomatic" PCD, symptoms and signs of AL amyloidosis should be solicited, since timely diagnosis is important in AL amyloidosis.