Non-IgM monoclonal gammopathy in patients with Sjögren's syndrome

Mono/polyclonal free light chains as challenging biomarkers for immunological abnormalities

Free light chain (FLC) kappa (k) and lambda (λ) consist of low molecular weight proteins produced in excess during immunoglobulin synthesis and secreted into the circulation. In patients with normal renal function, over 99% of FLCs are filtered and reabsorbed. Thus, the presence of FLCs in the serum is directly related to plasma cell activity and the balance between production and renal clearance. FLCs are bioactive molecules that may exist as monoclonal (m) and polyclonal (p) FLCs. These have been detected in several body fluids and may be key indicators of ongoing damage and/or illness. International guidelines now recommend mFLC for screening, diagnosis and monitoring multiple myeloma and other plasma cell dyscrasias. In current clinical practice, FLCs in urine indicate cast nephropathy and other renal injury, whereas their presence in cerebrospinal fluid is important for identifying central nervous system inflammatory diseases such as multiple sclerosis. Increased pFLCs have also been detected in various conditions characterized by B cell activation, i.e., chronic inflammation, autoimmune disease and HCV infection. Monitoring the coronavirus (COVID-19) pandemic by analysis of salivary FLCs presents a significant opportunity in clinical immunology worthy of scientific pursuit.

Free light chains and autoimmunity

The study of free light chains (FLCs) has grown as area of enormous interest for many clinicians with the aim of disclosing the exact biological role and potential use of FLCs in the clinical routine. Moreover, the attention given to immunological functions of FLCs has sparked a new light into their pathogenic contribution in different chronic autoimmune-based inflammatory diseases. The release of intracellular antigens following cell death or ineffective clearance of apoptotic debris, modification of self-antigens, and molecular mimicry may trigger the production of immunoglobulins after activation and polyclonal expansion of B cells, by which FLCs are released. The discovery of polyclonal FLCs as potential biomarkers started with the observation of their increased concentrations in a variety of biological fluids related to patients with autoimmune diseases. This review deals with the use of polyclonal FLCs for identifying severity and monitoring outcome after treatment in some autoimmune diseases, namely systemic lupus erythematosus, myasthenia gravis, systemic sclerosis, rheumatoid arthritis and Sjögren's syndrome, as supported by the fact that levels of FLCs correlate with both B cell activation markers and other specific markers of disease activity. In a near future, following the evidence shown, FLCs might probably work as early prognostic markers of severity and also as indicators of response to treatment or early assessment of relapse in selected autoimmune diseases.

Present and future of biologic drugs in primary Sjögren's syndrome

INTRODUCTION

Primary Sjögren's (pSS) syndrome is a chronic, autoimmune, and systemic disease characterized by xerostomia, xerophthalmia, muscle pain and fatigue. The disease may be complicated by a systemic involvement, such as a pulmonary fibrosis or the development of lymphoma which severely worsens the prognosis. Actually, there are no recommendations for the management of pSS. However, recent advances in the understanding of its pathogenesis have uncovered some pathways that have potential as therapeutic targets. Areas covered: In this review, the authors present the biologic drugs potentially valuable to the treatment of pSS in light of its physiopathology with a 'bird's eye' view of future prospects. The authors took into account relevant studies published from 2004 to 2016. Expert opinion: Biological treatment in pSS is a promising opportunity to potentially control disease activity and prevent its complication. Currently, inhibition of B-cell and IL-17 pathways seem to be the most promising avenues. New achievements in the knowledge of pSS pathophysiology are necessary in order to try to simultaneously predict the predominant pathogenic pathway, the kind of patients at major risk to develop a more severe disease, and the appropriate biological therapy to use.

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.

Serum hyperviscosity syndrome responding to therapeutic plasmapheresis in a patient with primary Sjögren's syndrome

Hyperviscosity syndrome is a disorder first described in patients with Waldenström's macroglobulinemia and is not commonly seen in rheumatic diseases. Its association with Sjögren's syndrome is very rare and it has been reported in very few patients. We report the case of a patient with primary Sjögren's syndrome presenting as hyperviscosity syndrome who was successfully treated with therapeutic plasma exchange.

Sjögren syndrome associated with multiple myeloma of the IgA κ-type

Abstract We report a case of a 62-year-old female patient with Sjögren syndrome (SS) who developed multiple myeloma (MM) of the IgA κ-type. In 1986, the patient was admitted to our hospital with a facial rash, keratoconjunctivitis sicca, and xerostomia. She was diagnosed as having discoid lupus erythematosus (DLE) and SS. She was treated with bromhexine hydrochloride for SS and with topical fluorinated steroid for DLE. In 1992, she developed compression fractures of the lumbar vertebrae and was readmitted to our hospital. DLE was not recognized. Laboratory findings revealed IgA 2046 mg/dl, IgG 529 mg/dl, and IgM 21 mg/dl. Anti-SS-A antibody was 1 : 32 and anti-SS-B antibody was 1 : 2. M protein of IgA κ was demonstrated by immunoelectrophoresis. Aspiration biopsy of the bone marrow revealed 20.2% plasma cells. A bone scintigram demonstrated many hot spots at the cervical and lumbar vertebrae. She was diagnosed as having SS and MM of the IgA κ-type. After chemotherapy for MM, the percentage of plasma cells in the bone marrow and the concentration of serum IgA decreased to 6.2% and 532 mg/dl, respectively. SS is frequently associated with benign monoclonal gammopathy or lymphoproliferative disorders, especially Waldenström's macroglobulinemia or malignant lymphoma. Although benign monoclonal gammopathy has frequently been observed in patients with SS, SS associated with MM is extremely rare.

Cryoglobulinemia in primary Sjögren's syndrome: prevalence and clinical characteristics in a series of 115 patients

OBJECTIVES

To determine the prevalence and nature of cryoglobulins in a large series of patients with primary Sjögren's syndrome (SS) and identify the clinical and immunologic features related to their presence.

METHODS

In a cross-sectional study, we investigated 115 consecutive patients (107 women and eight men) with primary SS. All patients fulfilled four or more of the preliminary diagnostic criteria for SS proposed by the European Community Study Group in 1993. Serum cryoglobulinemia was measured in all patients. Serum samples were obtained at 37 degrees C, and cryoglobulinemia was estimated by centrifugation after incubation at 4 degrees C for 7 days. The type of cryoglobulinemia was identified by agarose gel electrophoresis and immunofixation.

RESULTS

Cryoglobulins were detected in the sera of 18 (16%) of our patients with primary SS; most were IgMkappa monoclonal/IgG polyclonal. When compared with patients without cryoglobulins, those with cryoglobulins presented a higher prevalence of leukocytoclastic cutaneous vasculitis (56% v8%, P < .001), hypocomplementemia (75% v 2%; P < 0.001) and antibodies to hepatitis C virus (HCV) (47% v8%, P < .001). Liver involvement (clinical signs, biochemical features, or ultrasound/histological data of liver disease) was present in all patients (100%) with cryoglobulins and HCV infection but in only 11% of patients with cryoglobulins without HCV infection (P < .001).

CONCLUSIONS

Leukocytoclastic cutaneous vasculitis, hypocomplementemia, and HCV infection are associated with the presence of cryoglobulins in the sera of patients with primary SS. Testing for HCV infection is recommended for patients with SS and cryoglobulinemia because of its high prevalence and its strong association with liver disease.

Sjögren's syndrome terminating with multiple myeloma

We describe a patient (49 years old, female) with a more than 7-year history of both Sjögren's syndrome (SjS) and benign monoclonal gammopathy (BMG) of IgG lambda who later developed multiple myeloma (MM). SjS is frequently complicated with malignant lymphoproliferative disorders, especially malignant lymphoma or Waldenström's macroglobulinemia. Association of SjS with MM seems to be extremely rare, although BMG has been observed frequently in SjS, and there are many reports concerning the association between rheumatoid arthritis and MM.

Lymphoproliferative disease in SCID mice reconstituted with human Sjögren's syndrome lymphocytes

Patients with Sjögren's syndrome (SS) have increased frequency of non-Hodgkin's B-cell lymphoma. These lymphomas frequently use a specific subclass of kappa light chain (encoded by variable region gene segment Hum KV325) and exhibit bcl-2 protooncogene translocation t(14;18). In order to determine whether expansion of this B-cell subset could be reproduced in an animal model, immunodeficient SCID (CB-17) mice were reconstituted with lymphocytes from 4 different SS patients at high risk of the development of lymphoma. Tumor-like nodules developed in all 11 SCID mice that received at least 5 x 10(5) lymphocytes from SS salivary glands or peripheral blood samples. However, the tumor-like nodules in the SCID mice differed from SS lymphomas in vivo in that they (1) exhibited multiple immunoglobulin gene rearrangements; (2) did not have expansion of B-cells expressing the Hum KV325 K-light chain; and (3) lacked detectable t(14;18) translocations. Characterization of the SCID tumor-like nodules revealed a high level of Epstein-Barr virus (EBV) DNA, EBV-associated antigens (EA-R, EBNA-2, AND LMP), and the EBV-encoded cytokine BCRF-1 that is structurally similar to IL-10. These results demonstrate that the lymphoproliferation occurring in the salivary glands of SS patients is not reproduced in the SCID/hu chimeric mouse. It is likely that specific factors in the human salivary gland are required for development of lymphoma in SS patients and that such factors are not present in the SCID/hu chimeric mouse. Furthermore, EBV-induced lymphoproliferation, as seen in the SCID/hu chimera, does not lead to expansion of the same lymphoid subsets that occurs in vivo.

Association of serum IgM kappa monoclonicity in patients with Sjögren's syndrome with an increased proportion of kappa positive plasma cells infiltrating the labial minor salivary glands

Minor salivary gland biopsy specimens from 11 patients with primary Sjögren's syndrome with circulating monoclonal IgM kappa cryoglobulins, seven without cryoglobulins, and four patients with rheumatoid arthritis and Sjögren's syndrome (one with monoclonal and three with polyclonal cryoglobulins) were examined by the peroxidase antiperoxidase bridge technique, using antihuman kappa and lambda antibodies. In 6/11 patients with primary Sjögren's syndrome and in one patient with Sjögren's syndrome and rheumatoid arthritis with monoclonal cryoglobulins a predominance of plasma cells containing intracytoplasmic kappa light chains was found (kappa:lambda greater than 3:1). Two of those seven patients had immunohistological features of immunocytomas. In the other five patients with circulating monoclonal cryoglobulins the kappa:lambda ratio of positive cells did not exceed 3:1, while six out of seven patients without cryoglobulins and the patients with rheumatoid arthritis and Sjögren's syndrome with polyclonal cryoglobulins had almost equal numbers of kappa and lambda stained cells. One of seven patients with primary Sjögren's syndrome without cryoglobulins had an increased number of lambda light chain positive cells, indicating a non-secretory lambda monoclonal population. These findings suggest that the main area of B cell monoclonal expansion in primary Sjögren's syndrome may be the affected exocrine glands.

Hypergammaglobulinemic purpura of Waldenström

Hypergammaglobulinemic purpura of Waldenström is characterized by hypergammaglobulinemia, recurring purpura, an elevated erythrocyte sedimentation rate, and the presence of rheumatoid factor indicative of circulating immune complexes. There is a significant association with autoimmune diseases, especially Sjögren's syndrome and lupus erythematosus. Hypergammaglobulinemic purpura is considered primary when there is no other associated disease or secondary when associated with other diseases, usually autoimmune. Immune derangements are fundamental in its pathogenesis, although its cause is still unknown. Therapy is unrewarding and is probably unnecessary for this usually benign condition. Three cases are presented that are representative of patients with hypergammaglobulinemic purpura.

A high incidence of rheumatoid factor idiotypes in monoclonal proteins in the serum and in lymphoma cells in patients with Sjögren's syndrome

Patients with Sjögren's syndrome (SS) develop lymphoproliferative disorders such as monoclonal gammopathies and non-Hodgkin's lymphomas. Cross-reactive idiotypes (CRI) were studied in 22 serum monoclonal immunoglobulins (Igs) and in cytoplasmic Ig in four B-cell lymphoma cells in patients with SS. This was done by utilizing monoclonal anti-idiotypic antibodies which were produced against monoclonal rheumatoid factors (RF) derived from three patients with SS and one patient with Waldenström's macroglobulinemia. By the Western blotting or dot immunobinding technique, CRI was detected not only in monoclonal RFs but in monoclonal Igs which had different heavy- or light-chains from the original monoclonal RF used for immunization. A higher incidence of CRI was found in 22 monoclonal Igs associated with SS than in 27 monoclonal Igs in patients with Waldenström's macroglobulinemia, multiple myeloma or malignant lymphoma. In four patients with malignant lymphoma associated with SS, three showed one or three CRI in the lymphoma cells, whereas only two out of 20 patients with other malignant lymphoma showed CRI, demonstrating a significant difference between two groups. These data indicate that monoclonal proliferation of B-cell lineage in patients with SS, benign or malignant, takes place more often among RF-producing clones than other B-cell disorders.

Pulmonary lymphoma in Sjögren's syndrome

Sjögren's syndrome (SS) is an immunologic disease characterized by progressive destruction of the exocrine glands that causes mucosal and conjunctival dryness. In addition to the common pulmonary complications of diffuse interstitial lung disease, airways obstruction, desiccation of the upper respiratory tract, localized parenchymal nodules, recurrent tracheobronchitis, bronchiectasis, interstitial pneumonitis, and pleural effusion, patients with SS have a high risk of developing non-Hodgkin's lymphoma that may affect the lungs. Among 50 patients with SS and associated lymphoma, 10 had pulmonary involvement by lymphoma. The mean age of these 10 patients was 59.7 years, and 8 were women. The mean duration of SS was 7.2 years, and the mean interval between the onset of SS and lymphoma was 5.4 years. Cough and slowly progressive dyspnea were the most common pulmonary symptoms, and chest roentgenographic findings varied. Lung biopsies revealed a spectrum of low-to high-grade lymphomas, and high-grade lymphomas were associated with increased mortality. Of the 10 patients, 4 died from 8 to 48 months after lymphoma was diagnosed. We conclude that pulmonary involvement is common in patients with lymphoma associated with SS; thus, lymphoma should be considered in the differential diagnosis of pulmonary lesions in patients with SS.

Treatment of primary Sjögren's syndrome with hydroxychloroquine

Sjögren's syndrome is an autoimmune disease characterized by lymphocytic infiltration of the salivary/lacrimal glands, autoantibody production, and polyclonal hyperglobulinemia. In view of the efficacy and relative safety of hydroxychloroquine in other autoimmune disorders, the potential benefit of hydroxychloroquine (200 mg per day for 12 months) in 10 patients with Sjögren's syndrome was evaluated. Changes in levels of total immunoglobulin, antibody against Sjögren's syndrome-associated antigen B, rheumatoid factor, and in vitro production of immunoglobulin in the serum were evaluated. For comparison, 10 patients matched according to age and sex, who did not receive hydroxychloroquine were studied. In the hydroxychloroquine-treated group, the following observations were made: (1) significantly decreased total immunoglobulin G (IgG) and IgA levels with little change in IgM levels; (2) significant decrease in IgA-rheumatoid factor with a smaller decrease in IgM-rheumatoid factor; (3) decreased IgG anti-Sjögren's syndrome-associated antigen B autoantibody; and (4) decreased erythrocyte sedimentation rate and increased hemoglobin level. Further, a specific idiotype present on their rheumatoid factor (defined by monoclonal antibody 17-109) was significantly decreased, with disappearance of detectable circulating paraprotein in two hydroxychloroquine-treated patients. Finally, rheumatoid factor production in vitro by lymphocytes from hydroxychloroquine-treated patients using a T cell-dependent mitogen was significantly decreased. These results suggest that hydroxychloroquine modulates lymphoproliferation in patients with Sjögren's syndrome and may prevent progression to extraglandular sites of neoplastic transformation.

Two patients illustrating lymphoma transition and response to therapy in Sjögren's syndrome

Two patients with Sjögren's syndrome (SS) who subsequently developed malignant B-cell lymphomas are reported in detail. The first patient had both benign- and malignant-appearing lymphoid infiltrates on the same submandibular gland specimen and was successfully treated with combined chemotherapy and irradiation. The second patient developed cutaneous lymphoid infiltrates difficult to diagnose by light microscopy but containing a monoclonal IgM-Kappa population revealed by immunoperoxidase staining and immunoglobulin gene rearrangement studies. Her lesions resolved rapidly and completely on cyclophosphamide, recurred rapidly when this drug was discontinued, and resolved again on a second course of cyclophosphamide which is currently maintained at 50 mg daily. Both patients are doing well without recurrence two and three years after initial treatment. This clinical experience is presented to emphasize: (1) the clinical use of molecular biologic techniques to define the earliest appearance of malignant transformation in Sjögren's syndrome, and (2) the successful outcome that can be achieved with prompt institution of appropriate treatment. The phenomenon of lymphoma development in SS is discussed with regard to immunoregulatory abnormalities predisposing to malignancy in the setting of autoimmune disease.

Selective bone marrow involvement of lymphoplasmacytic cells secreting monoclonal IgA rheumatoid factor in a patient with Sjögren's syndrome and serum hyperviscosity

The clinical features and results of serological studies of a patient with Sjögren's syndrome, IgA kappa monoclonal gammopathy, and hyperviscosity syndrome are reported. The novel aspect of this case is the selective localisation to the bone marrow of lymphoplasmacytoid cells secreting IgA kappa morphologically identical to the cells infiltrating the salivary glands. The serum of the patient contained large amounts of immunoglobulin-anti-immunoglobulin immune complexes. By gel filtration chromatography it was shown that the immune complexes formed a peak of molecular weight 680 kilodaltons. The immune complexes were dissociable under acidic conditions. The immunoglobulin with rheumatoid activity was characterised as monoclonal IgA kappa protein. Treatment with plasmapheresis combined with immunosuppressive treatment with cyclophosphamide reduced the serum viscosity with concomitant clinical improvement.

Sjögren's syndrome: clinical and laboratory features, immunopathogenesis, and management

Sjögren's syndrome may be accompanied by local oral problems such as dry mouth, rampant caries, candidosis, or sialadenitis, but it is a systemic autoimmune disorder with wide repercussions, including a small premalignant potential. This article reviews the clinical and immunopathogenic features, as well as the etiology, of Sjögren's syndrome and discusses the diagnosis and management of oral complications.

Molecular forms of IgA rheumatoid factor in serum and synovial fluid of patients with rheumatoid arthritis

The distribution of molecular forms of serum IgA rheumatoid factor (IgA-RF) in 42 patients with rheumatoid arthritis was examined by solid-phase radioimmunoassay following fractionation by gel chromatography or ultracentrifugation in acidic buffer. Analysis of the fractions using phosphate buffered saline indicated that the IgA-RF in each serum was mainly polymeric. However, monomeric IgA-RF was detected in sera from approximately two-thirds of the patients, after dilution of chromatographic or ultracentrifugal fractions in diluent containing mouse monoclonal anti-human alpha chain antibody. The levels of monomeric IgA-RF (mean +/- SD 38 +/- 86 micrograms/ml) and the ratios of monomeric to polymeric IgA-RF (mean +/- SD 0.29 +/- 0.41) varied over a wide range. Paired synovial fluids from 9 of the patients were also examined. Monomeric IgA-RF was detected in each, although 2 samples demonstrated only minimal quantities. Neither form of IgA-RF was detected in serum from healthy adults when analyzed under the same conditions. Thus, both monomeric and polymeric IgA-RF can occur in serum and synovial fluid from patients with rheumatoid arthritis, and their proportions vary widely among patients.

Development of chronic lymphocytic leukaemia in a case of Sjögren's syndrome with systemic lupus erythematosus

Persistent lymphocytosis and intermittent fever were found in a 68-yr-old Chinese woman 5 yr after the diagnosis of Sjögren's syndrome with systemic lupus erythematosus (SLE). A series of examinations--including virology, bone marrow aspiration and surface markers of lymphocytes--was made to evaluate the nature of the lymphocytosis which had not been found previously. All of the results were consistent with the diagnosis of B-cell chronic lymphocytic leukaemia (CLL). Development of CLL in Sjögren's syndrome has seldom been described before and may be added to other malignancies associated with Sjögren's syndrome.

Human monoclonal IgM autoantibodies with restricted antigenic specificity for myelin express unrelated idiotypes

Idiotype-specific polyclonal antisera were prepared against myelin-binding human IgM paraproteins with specificity for the myelin-associated glycoprotein (MAG). Eight anti-idiotypic sera (6 against one monoclonal IgM and 2 against another) were tested by gel precipitation, immunoradiometric and ELISA assays for binding to the myelin-binding IgM paraproteins from 12 patients with demyelinating peripheral neuropathy. Anti-idiotypic antibodies bound only to the MAG-specific IgM used for immunization; there was no evidence of idiotypic cross-reactivity between the different IgM paraproteins.

Monoclonal gammopathies in Japanese patients with Sjögren's syndrome

We report 10 Japanese patients with Sjögren's syndrome (SS) who developed monoclonal gammopathies (MG). One was of the IgG class, five of IgA, three of IgM, and one of IgG/IgM. The monoclonality of 7 of 10 M proteins was studied using antiidiotypic (Id) antibodies against M proteins. Four (three IgA and one IgM) of 10 M proteins had rheumatoid factor (RF) activity. Hemagglutination inhibition tests and enzyme-linked immunosorbent assays (ELISA) showed that the RF activity was inhibited by anti-Id antibodies in all four monoclonal RFs. In two patients examined, many cells infiltrating into the salivary glands were stained with anti-Id antibodies. Our review of 19 Japanese SS patients with MG revealed that the non-IgM class predominated (13/19). This contrasts with 19 reported non-Japanese SS patients, among whom 14 were IgM. In both Japanese and non-Japanese patients there was a higher incidence of MG in primary than in secondary SS. The difference in the dominant heavy-chain class may reflect a difference in the genetic factors affecting B cell differentiation in immunologically disordered states.

Demonstration and identification of monoclonal proteins in the urine of patients with Sjögren's syndrome

Fresh sera and concentrated urine from 17 patients with primary Sjögren's syndrome (SS) were fractionated by high-resolution agarose electrophoresis to investigate the presence of monoclonal immunoglobulins or their components. Homogeneous protein bands were found in the gamma-globulin region in 47% of serum samples and 76% of urine specimens of all patients tested. These monoclonal proteins were detected more often in patients with extraglandular SS (77% in serum, 100% in the urine) than in patients with glandular SS (14% in serum, 43% in the urine). Immunofixation electrophoresis showed that the majority of these monoclonal proteins were free kappa or lambda light chains. Fractionation of unconcentrated parotid salivas from five SS patients failed to reveal the presence of monoclonal light chains or immunoglobulins. The present findings further substantiate our previous observation that a monoclonal process coexists with the polyclonal activation in SS patients.

Systemic lupus erythematosus with paraproteinemia

Nine patients (2.2%) in a group of 415 who were followed in a longitudinal prospective study of systemic lupus erythematosus (SLE) were found to have various monoclonal (M) proteins in their blood (IgG [6 patients], IgA [2 patients], IgM [1 patient]). No other findings compatible with plasmacytic dyscrasia were found. Bence Jones proteinuria was absent. Bone marrow aspirates and skeletal radiographs did not reveal any associated features of malignancy. Four of the 9 patients were under the age of 50. From the point of view of the M components, 3 groups emerged: transient (2 patients), persistently stable (6 patients), and increasing serum concentrations (1 patient). Using current measures of disease status, no correlation was apparent between the presence, type, and concentration of the M protein and the clinical and laboratory variables of lupus activity. Thus, M proteins were found in 2% of our SLE patients, but their relationship to the polyclonal B cell activation seen in this disorder, or perhaps to therapeutic modalities used in its treatment, remains to be elucidated.

The clinical picture of benign lympho-epithelial lesion

The histopathological diagnosis 'benign lympho-epithelial lesion' characterizes the major salivary gland disease in Sjögren's syndrome. It is not known if all cases with microscopically diagnosed benign lympho-epithelial lesion are variants of Sjögren's syndrome. The present clinical investigation showed that in 19 patients with the microscopical diagnosis of lympho-epithelial lesion, 84% fulfilled all criteria of Sjögren's syndrome. The rheumatoid factor and/or antinuclear factor was found in 84% and M-component was present in 16%. Sialography revealed sialectasis in all parotid glands. Salivary gland enlargement was found in 79%, and keratoconjunctivitis sicca in 89% of the patients. Systemic disease was found in 32%. The disease in the 2 patients with M-component took a malignant course, culminating in immunoblastic sarcoma and myelomatosis. The clinical diagnosis 'autoimmune sialadenitis' is proposed for the oral and salivary gland component is Sjögren's syndrome.