Increased risk of lymphoma in sicca syndrome

Sjögren's syndrome in a child

Sjögren's syndrome is a relatively uncommon condition in the paediatric age group. The youngest child reported thus far was a 5-year-old girl. This article reports the case of a 2-year-old girl admitted for recurrent infections of the respiratory tract with diffuse pulmonary interstitial infiltrations and a progressive swelling of the parotid glands. The clinical features and the results of laboratory investigations, including parotid and hepatic biopsies, chest X-rays and sialography helped to establish the diagnosis of Sjögren's syndrome. Clinical, immunological and genetic characteristics of Sjögren's syndrome are reviewed.

Pulmonary lymphomas and other pulmonary lymphoid lesions. A clinicopathologic and immunologic study of 64 patients

Sixty-four patients with lymphoid lesions involving the lung were separated into three groups. In 32 patients, the predominant lymphoid cell population consisted of small, mature-appearing round lymphocytes with or without plasmacytoid features. This group, designated small lymphocytic proliferation (SLP), represents a heterogeneous group of pulmonary lymphocytic lesions including small lymphocytic lymphoma, lymphocytic interstitial pneumonia, and lymphoid hyperplasia (pseudolymphoma). Thirteen SLP patients were identified as having small lymphocytic lymphoma on the basis of monoclonality, progressive disease in other sites, or both. This group was morphologically identical to the remainder of the SLP patients, except for a higher incidence of plasmacytoid features (P = 0.003) and a greater degree of mast cell infiltration (P less than 0.05). Four of these 13 patients subsequently developed an aggressive large cell lymphoma resulting in death in three patients. The median survival for all of the SLP patients has not yet been reached. Patients in whom a monoclonal cell population could be established showed a slightly worse prognosis of borderline statistical significance (P = 0.09); however, the presence of a serum monoclonal gammopathy conveyed a significantly worse prognosis (P = 0.003). The remaining two groups of patients had various forms of malignant lymphoma other than the small lymphocytic type. One group of 12 patients, designated as having presumed primary lymphoma limited to one or both lungs (PL), had a prolonged course with a median survival of 117 months. The remaining 20 patients had disseminated lymphoma also involving lung (DL); DL patients had a shorter median survival of 33 months.

Xerostomia: evaluation of a symptom with increasing significance

Xerostomia is the subjective sensation of oral dryness. Although it is most commonly associated with salivary gland dysfunction, it may also occur with normal gland activity. Xerostomia may be an early symptom of several morbid systemic conditions with important implications for the medical and dental management of patients. Oral dryness also has negative effects on an individual's emotional well-being and quality of life. The complaint of xerostomia necessitates a complete evaluation of a patient's general health, salivary gland function, and oral motor and sensory abilities. The salivary gland assessment includes symptom review, analysis of glandular secretions, scintiscanning, and minor labial gland biopsy. No single component is sufficient to adequately diagnose the presence, extent, or cause of salivary dysfunction. Treatment of a dry mouth, to date, is mainly palliative in nature, with the intent of preserving oral structures and functions. Better therapies are essential in the management of xerostomia, whatever the cause. The importance of xerostomia as a symptom is increasingly recognized in medicine and dentistry. The dentist is commonly the first health professional to hear this complaint and may be critical in directing a full and appropriate evaluation.

Circulating natural killer cells in Sjögren's syndrome

Reduced natural killer (NK) cell activity of peripheral blood lymphocytes (PBL) has been reported in a number of diseases including Sjögren's syndrome (SS). In this study, we used 2 monoclonal antibodies directed toward NK cells (anti-Leu-7 and anti-Leu-11) for determining NK cell activity in 29 patients with SS (9 with primary SS and 20 with secondary SS). The NK activity of PBL was simultaneously determined by the 51Cr release method using K562 as target cells. Contrary to previous reports, we did not find reduced NK activity of PBL in our patients compared with sex- and age-matched healthy controls. Although the percentage of Leu-7+ cells was significantly higher in the patients than in the controls (P less than 0.05), the absolute number of circulating Leu-7+ cells was not different between the groups. The percentage of Leu-11+ cells, however, was not significantly different between the patients and the controls, but the number of circulating Leu-11+ cells was significantly fewer in the patients than in the controls (P less than 0.05). Between the primary and secondary SS groups, no significant differences were found in NK cell activity or in the percentage of Leu-7+ or Leu-11+ cells. Furthermore, we found a significant correlation of NK activity with the percentage of Leu-11+ cells (P less than 0.05) in the controls as well as the SS patients, although a significant correlation was not identified between NK activity and the percentage of Leu-7+ cells.(ABSTRACT TRUNCATED AT 250 WORDS)

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.

Neoplasms of the immune system in rheumatoid arthritis

Two studies are reported of patients with rheumatoid arthritis. The first was a retrospective-prospective-prospective study and comprised a cohort of 489 patients with rheumatoid arthritis followed for a mean of 12.2 years. Lymphoproliferative malignancies developed in 10 patients (2.2 percent) after a mean interval of 11.8 years. The second was a study of 30 patients, from various centers in England, with rheumatoid arthritis and lymphoproliferative malignancies. The effects of chronicity of rheumatoid arthritis, drug therapy, and possible predisposing factors in the etiology of the lymphoproliferative malignancies were examined. Cytotoxic drugs could not be implicated in the pathogenesis of the lymphoproliferative malignancies, but phenylbutazone and D-penicillamine may have played a role in some cases. Current evidence supports the hypothesis that chronic synovitis in rheumatoid arthritis is associated with persistent activation of lymphocytes in lymph nodes and eventual malignant transformation in some cases.

Incidence of cancer in rheumatoid arthritis and other disorders after immunosuppressive treatment

A prospective study in the United Kingdom of 1,634 patients without transplants treated with immunosuppressive drugs (68 percent with azathioprine, 28 percent with cyclophosphamide) found an excess of non-Hodgkin's lymphoma and squamous cell skin cancer, suggesting that the excesses (although larger) of the same malignancies found among transplant recipients are not due solely to the foreign antigens of the graft. A separate analysis of the 643 patients with rheumatoid arthritis found a 13-fold increase of non-Hodgkin's lymphoma (whether treated with azathioprine or cyclophosphamide). This increase is not significantly different from the excess in similarly treated patients with other disorders in the study. In patients with rheumatoid arthritis not receiving immunosuppressive drugs, this excess is greater than that in a Finnish population and lower than that in another United Kingdom population. The findings are consistent with other evidence that immunosuppression favors the development of non-Hodgkin's lymphoma, which includes the excess of malignancies found among transplant recipients, long-term renal dialysis patients, and patients with certain primary immunodeficiency disorders. The higher risk among transplant recipients may reflect the effects of the foreign antigens, the more intensive immunosuppressive therapy, or both of these factors. In addition, the predilection for the brain, which is a well-known feature of the lymphomas after transplantation, may also apply (to a lesser extent) to other patients after immunosuppressive treatment, judging from the increasing numbers of case reports in such patients of this exceedingly rare type of malignancy. In view of the evidence of an increase of non-Hodgkin's lymphoma in rheumatoid arthritis in the absence of immunosuppressive treatment, any additional increase is likely to be small in absolute terms. Nevertheless, it needs to be weighed against the clinical benefits.

Review of United States data on neoplasms in rheumatoid arthritis

Relatively sparse literature developed during the past 30 years that sought to characterize the relationship of rheumatoid arthritis to neoplasms. The past decade has seen added concern over possible oncogenic effects of cytotoxic agents now used to manage some patients with rheumatoid arthritis. Acquisition of unambiguous data is complicated by the fact that the cumulative incidence of cancer in the general population exceeds 30 percent, and that most studies have insufficient patient numbers, duration follow-up, and attention to age, sex, race, or known etiologic agents. Thus, it is not surprising to find reports that cancer incidence is high, low, or unchanged in rheumatoid arthritis. Although equally ambiguous data were accumulated concerning potential neoplasm-inducing effects of cytotoxic drugs, concern is justified in relation to increased frequency of bladder cancer after cyclophosphamide and acute leukemia following alkylating agents.

Deficient helper cell function as a cause of diminished pokeweed mitogen blastogenic responses in patients with non-Hodgkin's lymphomas

An investigation has been made of immunoregulatory T-cell function in the non-Hodgkin's lymphomas by comparing immunoregulation of healthy control and patient peripheral blood lymphocyte blastogenic responses to pokeweed mitogen. Normal mononuclear leukocytes (MNL) had significantly higher responses than patient MNL. MNL were subsequently separated into T- and non-T-cell fractions by differential E-rosette sedimentation for co-culture experiments. When normal non-T-cells and autologous irradiated T-cells were recombined, the mitogenic response again exceeded the response of patient non-T-cells recombined with their own irradiated T-cells. However, when normal non-T-cells were co-cultured with patient irradiated T-cells, the mitogenic response was diminished. Moreover, when patient non-T-cells were co-cultured with normal irradiated T-cells, a normal proliferative response occurred. These differences in non-T-cell response are not simply a result of allogeneic effects, since normal non-T-cell responses were the same regardless of whether autologous or normal allogeneic irradiated T-cells were used as helpers. Furthermore, co-culture of normal non-T-cells simultaneously with autologous irradiated T-cells and patient irradiated T-cells revealed no diminution of blastogenic response compared with co-cultures of normal non-T-plus autologous irradiated T only, suggesting no net suppression by patient irradiated T-cells. Studies with monoclonal antibodies revealed that patient T-cells had normal to increased ratios of OK-T4+:OK-T8+ cells. These results suggest that peripheral blood T-cells from patients with non-Hodgkin's lymphomas, despite the presence of a normal to increased ratio of OK-T4+:OK-T8+ cells, are functionally deficient in their helper capacity for non-T-cell blastogenic response to pokeweed mitogen. Abnormal helper T-cell function may explain some of the immune deficits in patients with non-Hodgkin's lymphoma and may be important in the pathogenesis of these diseases.

Primary Sjogren syndrome: clinical and immunopathologic features

Primary Sjogren syndrome is an autoimmune condition in which dry eyes (keratoconjunctivitis sicca) and dry mouth (xerostomia) result from lymphocytic infiltration of lacrimal and salivary glands. Clinical and laboratory features of 60 primary Sjogren syndrome patients seen at our clinic during the past three years are presented. These patients illustrate the wide spectrum of extraglandular features that may occur as a result of lymphoid infiltration of lung, kidney, skin, stomach, liver, and muscle. They further emphasize the difficulty in classifying a patient as primary or secondary Sjogren syndrome (ie, sicca symptoms associated with systemic lupus erythematosus, rheumatoid arthritis, or scleroderma), particularly early in the disease course. As an initial step in understanding the pathogenesis, the lymphocytes that infiltrate the salivary glands and lymph nodes were characterized by using monoclonal antibodies that recognize distinct lymphocyte subsets and by using in vitro functional assays. These studies have demonstrated that affected tissues have infiltrates of T cells with helper/inducer activity and with a high frequency of "activation antigens." The immunohistologic techniques are useful in differentiating "benign" and "pseudolymphoma" lesions (both due predominantly to T cells) from non-Hodgkin lymphoma (usually due to B-cell infiltrates). Although there is no "cure" for primary Sjogren syndrome patient's symptoms may be significantly improved by measures aimed at prevention of ocular and dental complications and by the recognition of extraglandular features that may be amenable to specific treatment.

Malignancy in primary biliary cirrhosis. High incidence of breast cancer in affected women

Primary biliary cirrhosis is characterized by abnormalities in both cellular and humoral immunity. It is associated with presumably autoimmune diseases such as Sjögren's syndrome, rheumatoid arthritis, and scleroderma. Sjögren's syndrome and scleroderma have been noted to have an increased frequency of malignancy. Of 208 patients with primary biliary cirrhosis, followed for one month to 15.9 years, extrahepatic malignancies developed in 11, six of whom were women with breast cancer, and one with hepatocellular carcinoma. The incidence of breast cancer was 4.4 times (p less than 0.01) the incidence expected from the rate prevailing in the same age range in a comparable normal population. The incidence of cancer in sites other than the breast and of primary hepatocellular tumor was not significantly increased.

Non-Hodgkin's lymphomas

The non-Hodgkin's lymphomas, although sharing a common origin, often present physicians with wide variations in natural history and prognosis. The proper therapy of these diseases is based on an understanding of these differences and upon the information gained by pathologic review and staging, as well as the available chemotherapeutic and radiotherapeutic options.

Cancer morbidity in rheumatoid arthritis

A consecutive series of 489 patients with rheumatoid arthritis seen at the centre was studied to determine their cancer morbidity. Overall the 36 cancers diagnosed in the series between 1964 and 1981 were not significantly in excess of the expected number, but there was a highly significant excess of tumours of the reticuloendothelial system. The excess was mainly due to 6 observed cases of lymphoma. We conclude that there is a highly significant association between rheumatoid arthritis and the subsequent development of lymphoproliferative malignancy in this series.

Diffuse histiocytic lymphoma in a patient treated with cyclophosphamide for Wegener's granulomatosis

Diffuse histiocytic lymphoma developed in a 48-year-old man with Wegener's granulomatosis after nine years of therapy with cyclophosphamide. He died despite aggressive surgical and medical therapy for the lymphoma. This may be the first report of diffuse histiocytic lymphoma following treatment of Wegener's granulomatosis with cyclophosphamide. Recommendations for the approach towards extended therapy of smoldering Wegener's granulomatosis are discussed.

Lymphoproliferative malignancy in rheumatoid arthritis: a study of 20 cases

A series of 20 patients with definite or classical rheumatoid arthritis who subsequently developed a lymphoproliferative malignancy are described. The mean time between the onset of the 2 diseases was 13.2 years. A wide range of types of non-Hodgkin's lymphoma and Hodgkin's disease were found; there were no unusual histological features in the lymphomas. Although many of the patients had had gold, penicillamine, and other second-line drugs, none of them had received cytotoxic drugs, and there was no evidence that therapy was a cause of their malignancies. The likely cause of the association is a predisposition to both diseases.

Microbial pathogenicity in oral soft tissue diseases

Recent work implicating microbial factors in the pathogenesis of several oral soft tissue diseases is discussed. These conditions include recurrent aphthous ulceration, oral cancer, Sjogren's syndrome, and the oral lesions of AIDS (the acquired immune deficiency syndrome). This paper reviews some recent work on these topics, with emphasis on investigations in our laboratory.

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.

Polymorphous meningitis with atypical mononuclear cells in Sjögren's syndrome

Central nervous system complications in Sjögren's syndrome have been reported sporadically for years. We examined the nature and frequency of central nervous system abnormalities in 11 patients with clinically documented Sjögren's syndrome on whom postmortem examination was performed. In 9, characteristic mixed (polymorphous) inflammatory infiltrates containing large atypical mononuclear cells were observed in the leptomeninges, choroid plexus, or both; only 5 of the 9 neurological symptoms, however. Among patients with central nervous system lesions, 3 had definite vasculocentric inflammation and 1 had a necrotizing vasculitis with extensive subarachnoid hemorrhage. Four patients had evidence of chronic subarachnoid microhemorrhage associated with polymorphous meningitis. Atypical mononuclear cells in a polymorphous inflammatory exudate were observed in antemortem cerebrospinal fluid cytological specimens from 2 of the patients. The findings suggest that central nervous system involvement in Sjögren's syndrome is common and that neurological symptoms are related to polymorphous meningitis and vasculitis. Detection of atypical mononuclear cells in cerebrospinal fluid specimens may be of diagnostic value.

Natural killing activity in Sjögren's syndrome. An analysis of defective mechanisms

Natural killing (NK) by peripheral blood mononuclear cells (PBMC) against K562 cells was examined in 27 patients with Sjögren's syndrome and 17 normal controls. NK activity in the patients was significantly reduced compared with normal controls (34.6 +/- 3.4% versus 52.2 +/- 3.4%, P less than 0.001). Patients with secondary Sjögren's had lower cytotoxicity compared with those who had primary Sjögren's (28.5 +/- 5.5% versus 37.3 +/- 4.2%, P less than 0.01). The proportion of PBMC with characteristics of NK cells was not decreased in the patients. NK by normal PBMC was diminished both in the presence of sera from patients with reduced NK and when the effector cells were pretreated with the sera. Pretreatment of target K562 cells did not alter NK activity. Suppression of NK by sera from patients did not correlate with levels of immune complexes or with antilymphocyte antibodies. Some patients had adherent cells which inhibited NK function. Addition of either indomethacin or catalase partially restored NK activity in such patients, indicating that both prostaglandins and hydrogen peroxide play a role in suppression. These data suggest that multiple mechanisms are involved in the defective NK activity seen in patients with Sjögren's syndrome. The reduction of NK activity in Sjögren's syndrome may contribute to the increased incidence of lymphoid malignancy.

Use of monoclonal antibodies to analyze peripheral blood and salivary gland lymphocyte subsets in Sjögren's syndrome

Using monoclonal antibodies to cell surface antigens, we studied lymphocyte subsets in 15 patients with primary Sjögren's syndrome. The absolute number of OKT8-positive cells (reactive with T suppressor/cytotoxic cells) was significantly decreased in such patients (353 +/- 186/mm3) compared to age-matched controls (631 +/- 150/mm3) (P less than 0.001). The number of OKT4-positive cells (reactive with T helper/inducer cells) was comparable in both groups (932 +/- 588/mm3 versus 1.073 +/- 290/mm3). The ratio of OKT4/OKT8-reactive peripheral blood lymphocytes was increased (greater than 2.4) in 67% of these patients and ranged from 1.0 to 6.4 (normal = 1.8 +/- 0.3). OKT4-positive cells were the predominant subset in lip biopsy specimens stained with immunofluorescence or immunoperoxidase techniques; the OKT4/OKT8 ratio exceeded 3.0 in all 5 patients examined. In 1 patient with pseudolymphoma, a lymph node biopsy specimen contained 80% T cells with an OKT4/OKT8 ratio of 3.2. Thus, OKT4-positive cells predominated in the peripheral blood lymphocytes as well as in sites of inflammation in primary Sjögren's syndrome. The decreased number of OKT8-positive cells in primary Sjögren's syndrome was probably not caused by circulating autoantibody, since patients' sera did not react with normal OKT8-positive cells. Functional studies using pokeweed mitogen demonstrated that T helper cell activity for immunoglobulin synthesis was contained in the OKT4-positive subset in both normal and patients' peripheral blood lymphocytes. Removal of OKT8-positive cells by complement-mediated lysis did not lead to increased immunoglobulin synthesis or production of rheumatoid factor. The identification of peripheral blood lymphocyte subsets by use of monoclonal antibodies and the relationship of these subsets to tissue infiltrates and autoantibody production provide further insight into the pathogenesis of primary Sjögren's syndrome.

Antibody to cytomegalovirus in patients with Sjögren's syndrome. As determined by an enzyme-linked immunosorbent assay

By use of enzyme-lined immunosorbent assay (ELISA), patients with Sjögren's syndrome were found to have levels of serum IgG antibody to cytomegalovirus twice those of matched control subjects, and IgM antibody levels which were three times as high. It may be relevant that features of cytomegalovirus infection are similar to those of Sjögren's syndrome.

Studies of the function of natural killer-interferon system in patients with Sjögren syndrome

The natural killer (NK)-interferon (IFN) system is shown to be significantly involved in the resistance of host to viral infections and to tumours in numbers of animal models (1-4). The patients with Sjögren syndrome (SS) as well as those with collagen diseases were systematically investigated for the functions of NK-IFN system, including endogenous and augmented NK activity, IFN production, and responsiveness of NK cells to IFN stimulation, using virus persistently infected cells (heLa-measles cells) as target and stimulator cells. Although endogenous NK activity was not reduced, augmented NK activity by HeLa-measles cells in vitro was significantly depressed in patients with SS compared with that in age-matched normal controls. The patients with SS had also impaired capacity to produce IFN, which is shown to be a major factor regulating NK activity (5,6) in response to HeLa-measles cells in vitro. In three patients with SS who showed severely depressed NK activity, the effect of exogenous IFN was examined, and virtually no augmentation of NK activity was observed in all cases. Under the same condition, the normal controls demonstrated a dramatic increase in NK activity. The reduced IFN production was observed in all examined patients with SS, whereas impaired augmentation of NK activity by the stimulation with HeLa-measles cells as well as IFN seemed to be more striking in patients with the systemic manifestations of the disease, such as hypergammaglobulinemia and lymphoid hyperplasia. The possible involvement of dysfunction of NK-IFN system in the systemic manifestations of SS is discussed.

Thyroid abnormalities associated with treatment of malignant lymphoma

The effects on the thyroid of radiation therapy to the neck and/or chemotherapy were investigated in 54 Hodgkin's and 72 non-Hodgkin's lymphoma patients. These patients had received radiation therapy with doses ranging from 2000 to 4000 rad (median 3600 rad) to the cervical or mantle fields and/or multiple-agent chemotherapy following usual staging procedures. Palpable abnormalities of the thyroid were found in 15 patients. The patients with irradiation to the neck had a higher incidence of hypothyroidism than those patients treated with chemotherapy alone (31/74 vs. 8/52, P less than 0.001 for TSH and 10/74 vs. 1/52, P less than 0.025 for T4). A higher frequency of elevated serum TSH levels and antithyroid antibodies were also observed in patients receiving radiation therapy alone to the neck than in those receiving both radiation therapy and chemotherapy (19/33 vs. 12/41, P less than 0.025 for TSH and 16/33 vs. 7/41, p less than 0.01 for antibodies), suggesting that chemotherapy agents may reduce the thyroid dysfunction induced by irradiation. There was no difference in prevalence of elevated TSH levels following irradiation to the neck between patients in whom lymphangiogram was or was not performed (21/51 vs. 10/23).

Spectrum of Sjögren syndrome in children

Sjögren syndrome, consisting of keratoconjunctivitis sicca and xerostomia with or without another autoimmune disease, is uncommon in children. We describe our retrospective experience with eight pediatric patients with SS. All had recurrent parotid enlargement and abnormal salivary gland biopsies, six had keratoconjunctivitis sicca, and five had other autoimmune manifestations, although only two of these had other clearly defined autoimmune disorders (mixed connective tissue disease and hypergammaglobulinemic purpura). Our patients had a higher incidence of primary SS, parotid enlargement, and hematologic abnormalities than did children previously reported with SS. Children with SS demonstrate a clinical heterogeneity comparable to that seen in adults.

Immunoregulation in Sjögren's syndrome: influence of serum factors on T-cell subpopulations

21 patients with Sjögren's syndrome (sicca syndrome) with either glandular or extraglandular involvement, but without other connective tissue diseases, were studied with regard to immunoregulatory T-cell subpopulations, B-cell function, and suppressor cell capabilities. Patients with isolated glandular disease as well as patients with extraglandular disease had normal absolute numbers of total lymphocytes, T cells, and B cells. However, 9 of 11 patients with extraglandular disease and only 3 of 10 patients with glandular disease had decreased relative proportions of T cells bearing receptors for the Fc portion of immunoglobulin (Ig)G (T(G)) which was explained by a factor that blocked the expression of the IgG Fc receptor on T(G) cells. This blockage was reversible since the factor could be removed by trypsinizing the T cells before T(G) determination. Serum from patients with abnormal proportions of T(G) cells, but not serum from patients with normal proportions of T(G) cells, blocked the expression of the IgG Fc receptor on normal T cells. The serum factor upon fractionation over Bio-Gel A 1.5 columns as well as over staphylococcal protein A-Sepharose 4B columns was found diffusely within the IgG fraction, and not in the IgM fraction. Neither patients with glandular nor patients with extraglandular disease manifested increased numbers of in vivo-activated circulating lymphocytes as determined by spontaneous anti-trinitrophenyl (TNP) plaque-forming cells (PFC). However, patients with glandular disease had reduced numbers of pokeweed mitogen-induced anti-sheep erythrocyte PFC (P < 0.01) as compared with normals and patients with glandular disease. Of note was the fact that despite the modulation of T(G) subpopulation by the serum factor in patients with extra-glandular disease, these patients manifested normal concanavalin A-generated suppressor cells of pokeweed mitogen-induced PFC responses in allogeneic co-cultures. This was unlike the suppressor cell defect previously described in this system with systemic lupus erythematosus patients. The discrepancy was attributed both to the fact that the T(G) defect was reversible and to the fact that concanavalin A-generated suppressor cells are not limited to the T(G) subset. Thus, these studies have demonstrated reversible abnormalities in T(G) cells in patients with extraglandular Sjögren's syndrome which are not associated with suppressor cell defects. The discrepancy between these findings and the immuno-regulatory defects demonstrated in systemic lupus erythematosus may explain the difference in severity of the autoimmune expression in these diseases.