Discoid lupus erythematosus and monoclonal gammopathy

Autoimmunity, Infections, and the Risk of Monoclonal Gammopathy of Undetermined Significance

Various epidemiological studies, including case reports and -series in addition to larger, population-based studies, have reported an increased prevalence of monoclonal gammopathy of undetermined significance (MGUS) and multiple myeloma in individuals with a prior history of immune-related conditions. This is believed to support the role of chronic antigen stimulation in the pathogenesis of these conditions. In this short review, we summarize some of the largest population-based studies researching autoimmune diseases, infections, and the subsequent risk of MGUS, and discuss our understanding on its etiology and pathogenesis. Furthermore, we highlight important methodological limitations of previous studies in the field, but almost all studies on MGUS have been based on clinical, possibly biased, cohorts. Finally, we discuss future directions in researching the associations of MGUS and other disorders, including immune-related conditions, where screening studies play an important role.

Monoclonal gammopathy in systemic lupus erythematosus

We studied the prevalence, type and associated features of monoclonal gammopathy in patients with systemic lupus erythematosus (SLE). Patients included in the University of Toronto Lupus Database with an abnormal band on serum electropheresis were identified. Monoclonal gammopathy patients were matched with two controls each from the same database by age at SLE diagnosis, sex and disease duration. Of 1083 patients followed at the Lupus Clinic 59 (5.4%) were identified with monoclonal gammopathy. The gammopathies included 32 with IgG, 14 IgM and 12 IgA, one undefined. Nine (15.3%) malignancies were detected in monoclonal gammopathy and 12 (10.1%) in the controls during the entire course of their disease ( P = 0.13). None had multiple myeloma. There was no difference between patients with monoclonal gammopathy and their controls with respect to disease activity, damage, or dose of steroids. The mean ESR and gammaglobulin levels in the monoclonal gammopathy patients were higher than the controls at last visit. We conclude that monoclonal gammopathy is more frequent in SLE patients than in the general population and has a benign course in patients with SLE. There were no differences in disease manifestations, treatment approaches, or malignancies between SLE patients with and those without monoclonal gammopathy. Lupus (2007) 16, 426—429.

Disease associations with monoclonal gammopathy of undetermined significance: a population-based study of 17,398 patients

OBJECTIVE

To systematically study the association of monoclonal gammopathy of undetermined significance (MGUS) with all diseases in a population-based cohort of 17,398 patients, all of whom were uniformly tested for the presence or absence of MGUS.

PATIENTS AND METHODS

Serum samples were obtained from 77% (21,463) of the 28,038 enumerated residents in Olmsted County, Minnesota. Informed consent was obtained from patients to study 17,398 samples. Among 17,398 samples tested, 605 cases of MGUS and 16,793 negative controls were identified. The computerized Mayo Medical Index was used to obtain information on all diagnoses entered between January 1, 1975, and May 31, 2006, for a total of 422,663 person-years of observations. To identify and confirm previously reported associations, these diagnostic codes were analyzed using stratified Poisson regression, adjusting for age, sex, and total person-years of observation.

RESULTS

We confirmed a significant association in 14 (19%) of 75 previously reported disease associations with MGUS, including vertebral and hip fractures and osteoporosis. Systematic analysis of all 16,062 diagnostic disease codes found additional previously unreported associations, including mycobacterium infection and superficial thrombophlebitis.

CONCLUSION

These results have major implications both for confirmed associations and for 61 diseases in which the association with MGUS is likely coincidental.

Disease associations with monoclonal gammopathy of undetermined significance: a population-based study of 17,398 patients

OBJECTIVE

To systematically study the association of monoclonal gammopathy of undetermined significance (MGUS) with all diseases in a population-based cohort of 17,398 patients, all of whom were uniformly tested for the presence or absence of MGUS.

PATIENTS AND METHODS

Serum samples were obtained from 77% (21,463) of the 28,038 enumerated residents in Olmsted County, Minnesota. Informed consent was obtained from patients to study 17,398 samples. Among 17,398 samples tested, 605 cases of MGUS and 16,793 negative controls were identified. The computerized Mayo Medical Index was used to obtain information on all diagnoses entered between January 1, 1975, and May 31, 2006, for a total of 422,663 person-years of observations. To identify and confirm previously reported associations, these diagnostic codes were analyzed using stratified Poisson regression, adjusting for age, sex, and total person-years of observation.

RESULTS

We confirmed a significant association in 14 (19%) of 75 previously reported disease associations with MGUS, including vertebral and hip fractures and osteoporosis. Systematic analysis of all 16,062 diagnostic disease codes found additional previously unreported associations, including mycobacterium infection and superficial thrombophlebitis.

CONCLUSION

These results have major implications both for confirmed associations and for 61 diseases in which the association with MGUS is likely coincidental.

Monoclonal gammopathy of undetermined significance

Significant advances have been made in our understanding of the natural history, pathogenesis, mechanisms of progression and prognosis of monoclonal gammopathy of undetermined significance (MGUS). Although the overall incidence of MGUS progression is 1 per year, it is now possible to more accurately predict the risk of progression based on a new risk-stratification model. However, it is still hard to design chemopreventive trials given that the absolute risk of progression per year is low, even in the high-risk group. Therefore, further improvements in estimating the risk of progression are needed. Roughly 50% of MGUS may originate from primary translocation events at the heavy-chain immunoglobulin locus at chromosome 14q32. In most of the remaining MGUS patients, the initiating event is associated with genomic instability that results in hyperdiploidy of certain odd numbered chromosomes. Cytogenetically distinct subtypes of MGUS may carry significant differences in the risk of progression to malignancy. New markers, such as measures of bone marrow angiogenesis and circulating plasma cells may be additional prognostic factors. A better understanding of the mechanisms underlying the transition of normal plasma cells to the MGUS phenotype, and the transition of MGUS to myeloma or related malignancy, will help identify new risk factors for progression and new targets for chemopreventive interventions.

A serology-based approach combined with clinical examination of 125 Ro/SSA-positive patients to define incidence and prevalence of subacute cutaneous lupus erythematosus

OBJECTIVE

To estimate the incidence and prevalence of Ro/SSA-positive subacute cutaneous lupus erythematosus (SCLE) in Stockholm County, Sweden (1.8 million inhabitants) and to investigate the frequency of photosensitivity and other clinical manifestations associated with Ro/SSA autoantibodies.

METHODS

Ro/SSA-positive patients in Stockholm were identified via registry-based searches. All patients who tested positive for the presence of Ro/SSA autoantibodies during 1996-2002 (n = 1,323; 85% women) were identified. A questionnaire was sent to all patients still living in Stockholm in 2003 (n = 1,048). Patients who reported having skin symptoms and photosensitivity (n = 125) underwent a clinical examination.

RESULTS

Of the 741 (71%) of 1,048 Ro/SSA-positive patients who responded to the questionnaire, 400 (54%) reported having photosensitivity, and of these patients, 125 agreed to be clinically examined. A diagnosis of LE was confirmed in 59 of the 125 patients (SCLE in 20, systemic LE [SLE] in 33, and chronic CLE in 6). Eighty-six patients reported experiencing symptoms consistent with polymorphous light eruption (PLE). Comorbidities such as cardiovascular disease, autoimmune disease, and other skin diseases were common. The incidence of Ro/SSA-positive SCLE during the study period was estimated to be 0.7 cases per 100,000 persons per year and the prevalence was approximately 6.2-14 in 100,000 persons.

CONCLUSION

The incidence of Ro/SSA-positive SCLE in Stockholm County, Sweden is estimated to be 0.7 per 100,000 persons per year as compared with an incidence of SLE in Sweden of 4.8 per 100,000 persons per year. The prevalence is estimated to be 6.2-14 in 100,000 persons. Self-reported photosensitivity commonly corresponds to a history of PLE in Ro/SSA-positive patients, even when the clinical profile of SCLE is absent. Photoprotection should therefore be included in the treatment recommendations for these patients.

Monoclonal gammopathies of undetermined significance

The monoclonal gammopathies include multiple myeloma (MM), monoclonal gammopathy of undetermined significance (MGUS), primary systemic amyloidosis (AL), and Waldenström's macroglobulinemia (WM). At Mayo Clinic, almost 60% of patients with a monoclonal gammopathy have MGUS. MGUS is characterized by the presence of a serum monoclonal protein value <3 g/dL, fewer than 10% plasma cells in the bone marrow, no or a small amount of monoclonal protein in the urine, and absence of lytic bone lesions, anemia, hypercalcemia, or renal insufficiency related to the plasma-cell proliferative process. During long-term follow-up of 241 patients with MGUS seen at Mayo Clinic from 1956 to 1970, MM, WM, AL, or a related disorder developed in 64. To confirm the findings, we conducted a population-based study on MGUS in the 11 counties of southeastern Minnesota from 1960 to 1994. The risk of progression to a malignant plasma-cell disorder was 1% per year.

Monoclonal Gammopathy of Undetermined Significance

Monoclonal gammopathy of undetermined significance (MGUS) is characterized by the presence of a monoclonal protein (M-protein) without evidence of multiple myeloma (MM), Waldenstrom's macroglobulinemia (WM), amyloidosis (AL), or a related plasma cell proliferative disorder. Agarose gel electrophoresis followed by immunofixation is recommended for recognition of an M-protein. Monoclonal gammopathy of undetermined significance is found in approximately 3% of persons > 70 years of age and in about 1% of those > 50 years old. In a series of 1384 patients from Southeastern Minnesota in whom MGUS was diagnosed at Mayo Clinic from 1960 through 1994, the risk of progression was 1% per year. This risk of progression continued even after > or = 25 years of a stable M-protein. The risk for developing MM, WM, or AL was increased 25-fold, 46-fold, and 8.4-fold, respectively. The concentration of the serum M-protein, abnormal serum free light-chain ratio, and the presence an immunoglobulin (Ig)M or an IgA M-protein were risk factors for progression. The presence of a urine M-protein or the reduction of > or = 1 uninvolved immunoglobulins was not a risk factor for disease progression. Patients must be monitored for progressive disease throughout their lives. Variants of MGUS consist of IgM MGUS, biclonal gammopathies, triclonal gammopathies, idiopathic Bence Jones (light-chain) proteinuria, and IgD MGUS. Monoclonal gammopathy of undetermined significance may be associated with many disorders, including lymphoproliferative diseases, leukemia, von Willebrand's disease, connective tissue diseases, and neurologic disorders. Epidemiologic and statistical methods must be used to evaluate these associations.

Monoclonal gammopathies and associated skin disorders

The monoclonal gammopathies are characterized by clonal proliferation of plasma cells and other clonally related cells in the B-cell lineage. These disorders include monoclonal gammopathy of undetermined significance, multiple myeloma, Waldenström macroglobulinemia, heavy chain diseases, plasmacytoma, and primary amyloidosis. Many skin disorders have been described in association with monoclonal gammopathies. This article provides an introduction to the definition, detection, natural course, and spectrum of monoclonal gammopathies and a brief discussion of pathogenesis. The article also reviews the skin disorders associated with monoclonal gammopathies, categorizes the association, and evaluates the strength of the association.

Systemic lupus erythematosus and multiple myeloma: a rare association

OBJECTIVE

The association of systemic lupus erythematosus (SLE) and multiple myeloma (MM) is an uncommon event. We report the relapse of SLE in a patient with a previous history of MM, treated with chemotherapy and, subsequently, with alpha-2b interferon (alpha-2b IFN) as a maintenance therapy. The case is discussed in light of past relevant literature.

METHODS

The history and clinical, laboratory and radiographic findings of the patient, as well as the subsequent therapeutic approach are discussed. In our review of the literature, journal articles are identified by Medline search.

RESULTS

We describe the case of a woman who developed a multiple myeloma 14 years after a diagnosis of SLE. A careful literature review confirms that the association of these two diseases has been reported only in a few cases. When the plasma cell neoplasia occurred, SLE had been quiescent for several years; the patient was treated with prednisone-melphalan and, subsequently, with alpha-2b IFN as a maintenance therapy. On admission to our department, SLE was in a relapse phase, probably because of IFN treatment. The disease was poorly responsive to steroid therapy and required the use of cytotoxic drugs.

CONCLUSIONS

The coexistence of SLE and MM is very rare and the possible pathogenetic mechanisms underlying this association remain unclear. The use of interferon in a patient with an autoimmune disease always invites caution.

Monoclonal gammopathy in systemic lupus erythematosus

In order to ascertain the incidence of monoclonal gammopathy (MG) in systemic lupus erythematosus (SLE), 120 SLE patients were evaluated. Four patients (3.3%), two of whom were under 50 years of age, were found to have a monoclonal immunoglobulin in their serum. Our data agree with the previous literature in demonstrating a higher incidence of MG in SLE patients in comparison with the general population. Neither the clinical importance nor the pathogenetic significance of this association is known.

Plasma cell dyscrasias: current status

This is a review of the current status of the monoclonal gammopathies (plasma cell dyscrasias). We begin with the recognition of a monoclonal protein in serum and urine. We briefly discuss the differential diagnosis of the monoclonal gammopathies. Clinical and laboratory findings as well as the management of multiple myeloma are addressed. Future approaches for the treatment of myeloma are provided. The variant forms of multiple myeloma, including smoldering myeloma, plasma cell leukemia, nonsecretory myeloma, IgD myeloma, osteosclerotic myeloma, solitary plasmacytoma of bone, and extramedullary plasmacytoma, are briefly reviewed. Diagnosis and treatment of Waldenström's macroglobulinemia are presented. The recognition and differential diagnosis of the heavy-chain diseases (gamma, alpha, and mu) are included. Monoclonal gammopathy of undetermined significance ("benign" monoclonal gammopathy) is presented in detail. Amyloidosis is not included in this review.

Myeloma, paraproteinemias, and the skin

This review focuses on those systemic diseases or syndromes associated with monoclonal plasma cell disorders that may present with important cutaneous manifestations. Amyloidosis, POEMS syndrome, cutaneous plasmacytoma, xanthomas, benign hypergammaglobulinemic purpura of Waldenström, and scleromyxedema are emphasized.