Neuropsychiatric disease in Sjögren's syndrome: anti-ribosomal P and anti-neuronal antibodies

Exploring the Psychiatric Manifestations of Primary Sjögren's Syndrome: A Narrative Review

Background

Primary Sjögren's syndrome (pSS) is recognized for its autoimmune origin. Its hallmark symptoms, dry eyes and mouth, result from glandular inflammation. Prior literature indicates that pSS not only affects the peripheral system but also involves the central nervous system (CNS), giving rise to various neuropsychiatric symptoms. However, there is limited published research on the psychiatric comorbidities in individuals with pSS.

Methods

A comprehensive search was conducted on PubMed and Google Scholar for this narrative review. The search spanned from inception until August 2023. Its aim was to locate studies focusing on the psychiatric manifestations of pSS and the potential underlying mechanisms.

Results

The most commonly reported psychiatric complications among these individuals are depression and cognitive dysfunction. Other psychiatric manifestations that have been reported in pSS individuals include anxiety, sleep disorders, psychosis, catatonia, bipolar disorder, and obsessive-compulsive disorder.

Conclusion

In conclusion, patients with pSS often display multiple psychiatric symptoms. These symptoms can significantly impair functioning and reduce quality of life. Hence, prompt diagnosis and management are crucial.

Adolescent Sjogren's syndrome presenting as psychosis: a case series

BACKGROUND

Neurological involvement has been reported in up to 80% of adults with Primary Sjogren's syndrome (pSS) with psychiatric abnormalities including anxiety, depression, and cognitive dysfunction being common. Psychosis due to pSS has been reported in adult patients but has never been previously reported in the adolescent/pediatric literature. Here we describe for the first time four cases of adolescent Sjogren's syndrome that presented with psychotic symptoms. Rituximab treatment was followed by improvement of psychiatric symptoms in all patients.

CASE PRESENTATION

1: 16 year old female without significant past medical history presented to the emergency department with 4 days of abnormal behavior, tremors, insomnia, polyphagia, polyuria, and suicidal ideation. 2: 16 year old female with a 4 year history of severe anxiety, OCD, and tic disorder treated with fluoxetine with partial benefit presented with an abrupt and severe worsening of anxiety, OCD and new auditory hallucinations. 3: 19 year old female without significant past medical history presented with a 3 day history of progressively altered behavior, incoherent speech, insomnia, headache, and tangential thoughts. 4: 17 year old female without significant past medical history presented with new onset suicidal ideation, paranoia, confusion, and emotional lability.

CONCLUSION

Psychosis is more common in autoimmune disease than previously known. To our knowledge, the four teenage women described above are the first reported patients with adolescent pSS manifesting as psychosis. pSS should be considered in the differential diagnosis of young patients with new psychiatric disorders, even in the absence of sicca symptoms. Psychiatric symptoms improved with rituximab infusions in all 4 of our patients, which suggests rituximab may be an effective treatment option that should be considered early after the diagnosis of pSS-associated psychiatric disturbance.

One patient with Sjogren's syndrome presenting schizophrenia-like symptoms

Comorbid depression in patients with Sjogren's syndrome has been reported frequently, while comorbid psychosis in subjects with Sjogren's syndrome has rarely been reported. Here we report a patient with Sjogren's syndrome who presented with schizophrenia-like symptoms such as persecutory delusions and auditory hallucinations in contrast to her previous psychiatric presentations, which only included depression and anxiety.

A Systematic Review of Peripheral and Central Nervous System Involvement of Rheumatoid Arthritis, Systemic Lupus Erythematosus, Primary Sjögren's Syndrome, and Associated Immunological Profiles

Both central (CNS) and peripheral nervous system (PNS) complications are frequent and varied in connective tissue diseases. A systematic review was conducted between 1989 and 2014 in the databases Medline, Scopus, and Cochrane Library using the search terms, peripheral and central nervous complications and immunological profiles, to identify studies in specific connective tissue disorders such as rheumatoid arthritis, systemic lupus erythematosus, and primary Sjögren's syndrome. A total of 675 references were identified, of which 118 were selected for detailed analysis and 22 were included in the final review with a total of 2338 participants. Our search focused only on studies upon connective tissue disorders such as rheumatoid arthritis, systemic lupus erythematosus, and primary Sjögren's syndrome associated with seroimmunological data. The reported prevalence of CNS involvement ranges from 9 to 92% across the reported studies. However, the association between CNS and PNS manifestations and seroimmunological profiles remains controversial. Τo date, no laboratory test has been shown as pathognomonic neither for CNS nor for PNS involvement.

Sjögren's syndrome and neuromyelitis optica spectrum disorders (NMOSD)--a case report and review of literature

BACKGROUND

Neuromyelitis optica (NMO) is a rare relapsing auto-immune disease of the central nervous system which is sometimes found in association with other autoimmune disorders including Sjogren's syndrome. We present the case of a middle aged female with Sjogren's syndrome (SS) and Neuromyelitis optica spectrum disorders (NMOSD) who had a rapidly declining neurological illness that responded to immunosuppressive therapy.

CASE PRESENTATION

A 51-year-old female with Sjogren's syndrome and recent history of varicella zoster infection presented with right upper and lower extremity weakness of one week duration. She was noted to have contrast enhancement at C2-C4 cord levels on cervico-thoracic MRI. Comprehensive work up was negative except for presence of a mild lymphocytic pleocytosis and oligoclonal bands in the CSF. She was diagnosed with transverse myelitis secondary to varicella zoster infection and was treated with high dose steroids in addition to acyclovir with improvement in her symptoms. Two months later she developed left upper and lower extremity weakness, bilateral dysesthesias and urinary incontinence. Repeat MRI of the cervico-thoracic spine revealed worsening enhancement at lower cervical cord levels (C5-7) with extension to T1. CSF analysis was unchanged; however immunological work up was abnormal for elevated NMO-IgG/AQP4 antibody. She was diagnosed with NMOSD and was treated with immunosuppressive therapy. Initially with IV methylprednisone and Cyclophosphamide therapy followed by Mycophenolate mofetil (MMF) maintenance therapy with good response. Repeat MRI 6 months later showed near complete resolution of previous abnormal cord signal changes.

CONCLUSION

One needs to recognize the relationship between autoimmune diseases especially SS and NMOSD. The presence of NMO antibody has been associated with a relapsing disease course and a careful follow-up, besides use of remission maintenance agents such as MMF and Azathioprine are important to consider.

Psychiatric manifestations of primary Sjögren's syndrome: a case report and literature review

A 54-year-old woman diagnosed with primary Sjögren's syndrome in 2007 presented with a 1-year history of visual hallucinations requiring admission to a psychiatric unit. The hallucinations resolved while on olanzapine and hydroxychloroquine but recurred when they were stopped. Despite restarting olanzapine, her visual hallucinations persisted. When she started a tapering dose of prednisolone, all the hallucinations resolved. This report adds to the small literature on psychiatric manifestations of Sjögren's syndrome and provides evidence that low-dose corticosteroids may be an effective treatment for this manifestation.

Global trends, potential mechanisms and early detection of organ damage in SLE

Increased longevity of patients with systemic lupus erythematosus (SLE) leads to chronic organ damage accrual, which reduces the possibility of further survival improvement in patients with the disease. Observations from lupus centres worldwide revealed that the prevalence of damage occurring in the cardiovascular system in patients with SLE has increased over the past four decades. The results of a meta-analysis involving over 70 observational studies demonstrated that lupus-related organ damage involving the neuropsychiatric and renal systems also remains a major factor that limits survival improvement in patients with this disease. While efforts to halt acute lupus-related injury are continuing, through early diagnosis and effective use of immunosuppressive agents, a concomitant strategy to improve survival of patients with SLE would be early detection and timely treatment of lupus-related organ damage with meticulous monitoring. This Review discusses the pattern and trend of organ damage in patients with SLE worldwide, the potential serological and genetic mechanisms of organ damage, and the advances in research on potential tools for early detection of lupus-related organ damage, such as functional brain imaging techniques, measurement of endothelial function, identification of biomarkers from body fluids, and development of risk calculation models.

Neurological Disorders in Primary Sjögren's Syndrome

Sjögren's syndrome is an autoimmune disease characterized by an autoimmune exocrinopathy involving mainly salivary and lacrimal glands. The histopathological hallmark is periductal lymphocytic infiltration of the exocrine glands, resulting in loss of their secretory function. Several systemic manifestations may be found in patients with Sjögren's syndrome including neurological disorders. Neurological involvement ranges from 0 to 70% among various series and may present with central nervous system and/or peripheral nervous system involvement. This paper endeavors to review the main clinical neurological manifestations in Sjögren syndrome, the physiopathology, and their therapeutic response.

Primary Sjögren's Syndrome: health experiences and predictors of health quality among patients in the United States

Objective

To assess the health related quality of life of patients with primary Sjögren's Syndrome (PSS) in a large US sample.

Methods

Questionnaires were mailed to 547 patients with a confirmed diagnosis of PSS (PhysR-PSS) and all active members of the Sjögren's Syndrome Foundation USA (SSF-PSS), half of whom identified a friend without PSS to also complete the survey.

Results

277 PhysR-PSS patients were compared to 606 controls. The mean age was 62 years in the PhysR-PSS group and 61 years in the control group. 90% in both groups were women. Time from first symptom to diagnosis of PSS was a mean of 7 years. Sicca related morbidity, fatigue severity, depression and pain (assessed by validated questionnaires, PROFAD-SSI, FACIT-F, CES-D, BPI) were significantly greater, and all eight SF-36 domains were significantly diminished, in patients compared to controls. Somatic fatigue was the dominant predictor of physical function and of general health. Depression was the dominant predictor of emotional well being. Health care utilization was higher in patients than controls, including out of pocket dental expenses (mean: PhysR-PSS = $1473.3, controls = $503.6), dental visits (mean: PhysR-PSS = 4.0, controls = 2.3), current treatments (mean: PhysR-PSS = 6.6, controls = 2.5), and hospitalizations (53% PhysR-PSS, vs. 40% controls).

Conclusion

Diminished health quality and excess health costs are prevalent among PSS patients. Health experiences and functional impact of PSS is similar among US and European patients. Delayed diagnosis, sicca related morbidity, fatigue, pain and depression are substantial suggesting unmet health needs and the importance of earlier recognition of PSS.

Sjögren's syndrome in dermatology

Sjogren's Syndrome (SS) is a systemic autoimmune disease characterized by dry eyes (keratoconjunctivis sicca) and dry mouth (xerostomia). To fulfill diagnostic criteria, patients must have objective signs of dryness on examination and laboratory confirmation of an autoimmune process as evidenced by a positive autoantibody to SS-A antigen or a characteristic lip biopsy. SS may exist as a primary condition or in association with other systemic autoimmune disorders (termed secondary SS) such as rheumatoid arthritis, systemic lupus erythematous (SLE), progressive systemic sclerosis (scleroderma), or dermatomyositis. Exclusions to the diagnosis include pre-existing lymphoma, hepatitis C or HIV infection. Pathogenesis involves both genetic (especially HLA-DR) and environmental factors. Both T-cells and B-cells are involved in the generation of cytokines and chemokines within the glands. The epithelial cells of the glands also play a role in pathogenesis. The dermatologic manifestations range from drynessness (sicca) and its complications to vasculitis. There is a significant overlap in the clinical manifestations, as well as treatment, of SS and SLE. However, SS patients require special attention to the complications of ocular dryness (keratocojunctivitis sicca and blepharitis) and oral dryness (rapid tooth loss and oral candidiasis) SS patients have a markedly increased risk of lymphoma and enlarged lymph nodes or persistently enlarged parotid/submandibular glands that require further evaluation.

Diseases of white matter and schizophrenia-like psychosis

OBJECTIVE

To analyse the available data regarding the presentation of psychosis in diseases of central nervous system (CNS) white matter.

METHOD

The available neurological and psychiatric literature on developmental, neoplastic, infective, immunological and other white matter diseases was reviewed.

RESULTS

A number of diseases of the white matter can present as schizophrenia-like psychoses, including leukodystrophies, neoplasms, velocardiofacial syndrome, callosal anomalies and inflammatory diseases.

CONCLUSIONS

Production of psychotic symptoms may result from functional asynchrony of interdependent regions, due to alterations in critical circuits as a result of pathology. The nature, location and timing of white matter pathology seem to be the key factors in the development of psychosis, especially during the critical adolescent period of association area myelination. Diseases that disrupt the normal formation of myelin appear to cause psychosis at higher rates than those that disrupt mature myelinated structures. Diffuse rather than discrete lesions, in particular those affecting frontotemporal zones, are also more strongly associated with schizophrenia-like psychosis. These illnesses point to the central role that white matter plays in maintaining CNS connectivity and to how pathology of the white matter may contribute to the neurobiology of psychosis.

Sjögren's syndrome

Sjögren's syndrome is a chronic autoimmune disorder of the exocrine glands with associated lymphocytic infiltrates of the affected glands. Dryness of the mouth and eyes results from involvement of the salivary and lacrimal glands. The accessibility of these glands to biopsy enables study of the molecular biology of a tissue-specific autoimmune process. The exocrinopathy can be encountered alone (primary Sjögren's syndrome) or in the presence of another autoimmune disorder such as rheumatoid arthritis, systemic lupus erythematosus, or progressive systemic sclerosis. A new international consensus for diagnosis requires objective signs and symptoms of dryness including a characteristic appearance of a biopsy sample from a minor salivary gland or autoantibody such as anti-SS-A. Exclusions to the diagnosis include infections with HIV, human T-lymphotropic virus type I, or hepatitis C virus. Therapy includes topical agents to improve moisture and decrease inflammation. Systemic therapy includes steroidal and non-steroidal anti-inflammatory agents, disease-modifying agents, and cytotoxic agents to address the extraglandular manifestations involving skin, lung, heart, kidneys, and nervous system (peripheral and central) and haematological and lymphoproliferative disorders. The most difficult challenge in diagnosis and therapy is patients with symptoms of fibromyalgia (arthralgia, myalgia, fatigue) and oral and ocular dryness in the presence of circulating antinuclear antibodies.

Central nervous system disease in primary Sjögren’s syndrome: The role of magnetic resonance imaging

OBJECTIVES

To examine the frequency of central nervous system (CNS) disease in primary Sjogrens syndrome (pSS) and indicate ways in which cerebral magnetic resonance imaging (MRI) may help determine the significance of CNS involvement.

METHODS

The current review was based on a Medline (Pubmed) literature search through May 2003, focused on Sjogrens syndrome, other vasculitides, multiple sclerosis (MS), specific MRI techniques, and MRI findings with regard to the above-mentioned diseases. Additional literature was identified in the reference sections of articles listed in Medline.

RESULTS

Severe CNS manifestations reminiscent of MS have been described in pSS patients. Moreover, the prevalence of nonfocal neuropsychological abnormalities has been found to be elevated in some pSS patient populations. MRI studies suggest discrete cerebral tissue damage even in neurologically asymptomatic patients. However, small white matter lesions are nonspecific and may be related to age or cerebrovascular risk factors such as hypertension. A large controlled study, complementing established T2-weighted MRI with fluid-attenuated inversion recovery (FLAIR) to achieve high sensitivity in lesion detection, could indicate the disease specificity of white matter lesions in pSS. Newer MR techniques, such as spectroscopy and magnetization transfer imaging, applied, for example, in MS and systemic lupus erythematosus (SLE) to evaluate CNS tissue injury, could help determine the extent and mechanisms of macroscopic and microscopic CNS lesions in pSS.

CONCLUSIONS

Future controlled studies will be necessary to more precisely estimate the prevalence of CNS lesions in pSS, specifically of discrete white matter abnormalities. Newer MRI techniques have the potential to provide information on the severity and pathophysiological mechanisms of CNS tissue damage.

An autopsied case of Sjögren's syndrome with massive necrotic and demyelinating lesions of the cerebellar white matter

A 69-year-old woman developed subacute cerebellar ataxia and tremors in all four limbs in April 1996. Laboratory examination showed elevated antibodies against Ro and La. Head magnetic resonance imaging showed T(2) high-intensity lesions in the cerebellar white matter bilaterally and later in the pons. In April 2000, she died of multiple organ failure with incidental colon cancer. The autopsy showed atrophic parotid glands with an accumulation of lymphocytes around the ducts, confirming the diagnosis of Sjogren's syndrome histopathologically. The neuropathological examination revealed severe necrotic lesions in the cerebellar white matter bilaterally with several foci of perivenous demyelination in the periphery of the lesions and similar demyelinated areas in the pons. Immunohistochemistry with anti-JC virus antibody demonstrated no positive inclusions. A single focus of granulomatous arteritis was observed in one subarachnoid artery. The combination of Sjogren's syndrome, granulomatous angitis, and foci of perivenous demyelination suggests that an autoimmune mechanism played an important role in causing the necrotic lesions in the cerebellar white matter in this case.

Antiribosomal P protein antibodies in Chilean SLE patients: no association with renal disease

The objective of this work was to determine the frequency and clinical associations of anti-ribosomal P protein antibodies (Anti-P) in a cohort of Chilean patients with systemic lupus erythematosus (SLE). Between 1996 and 1998, 141 consecutive patients with SLE were examined prospectively according with a standard protocol. Disease activity was measured by MEX-SLEDAI in 138 patients. Anti-P positivity was determined by double immune diffusion or Western blot and ELISA. Anti-P was found in 21 (15%) patients. In the Anti-P positive patients recent onset SLE (disease duration of 1 year or less) was more frequent (P = 0.018). Anti-P was found in 23% of 83 patients with active SLE vs 4% of the 55 patients with inactive SLE (Yates corrected P = 0.00479). An association with anti-dsDNA antibodies by Farr assay was observed. Anti-P positive patients had a median Farr of 65 IU/ml (1.4-1240) and Anti-P negative of 12 IU/ml (1.4-992; P-value = 0.0084). During the study only two patients had lupus psychosis and they were Anti-P positive. No association was found with liver disease (six patients, two with Anti-P antibodies) or active glomerulonephritis (22 patients four with Anti-P). Our data shows that the presence of Anti-P antibodies supports the clinical diagnosis of lupus psychosis.

Motor weakness and cerebellar ataxia in Sjögren syndrome--identification of antineuronal antibody: a case report

We report here a combination of rare neurological manifestations of primary Sjögren syndrome (SS), such as motor-dominant motor weakness of peripheral origin, cerebellar ataxia and depression, in a Japanese female patient. An autoantibody in her serum and cerebrospinal fluid immunolabelled spinal motor neurons and cerebellar Purkinje cells. On Western blot, this antibody reacted with a protein of 34 kDa from the extract of spinal cord, dorsal root ganglion, or cerebellar cortex, which might correspond to motor weakness and cerebellar ataxia, respectively. The absence of its reactivity to the liver tissue indicates that this autoantibody targets an antigen represented exclusively in the neural tissues. Although it remains to be proved how autoantibodies, sometimes associated with SS, are involved in the development of clinical pictures, some of them are present in the cerebrospinal fluid and exhibit an exclusive affinity to neural tissues, which indicates its plausible link to neurological manifestations. Recognition of these antineuronal antibodies in SS will potentially provide a chance to treat these patients by removing or inactivating the antibody.

CNS involvement in primary Sjögren's syndrome: prevalence, clinical aspects, diagnostic assessment and therapeutic approach

Among the systemic manifestations of primary Sjögren's syndrome, neurological involvement is still an intriguing and debated issue. Although peripheral nervous system abnormalities are a well documented occurrence with a reported prevalence ranging from 10 to 20%, opinions differ as to the prevalence of CNS disease, with suggestions from 'nonexistent' to 'very common'. The lack of agreement probably reflects the different populations selected, different inclusion criteria and lack of rigorous epidemiological studies. In our experience, CNS involvement was detected in 7 of 87 (8%) unselected consecutive patients observed over a period of 5 years. The spectrum of CNS involvement is wide, including focal, diffuse, neuropsychiatric and spinal cord symptoms, frequently characterised by insidious onset, remitting course and, sometimes, progressive evolution. The diagnostic approach enabling early recognition of this complication relies on careful clinical assessment using history and physical examination combined with neuropsychological testing and instrumental, laboratory and imaging investigations such as magnetic resonance imaging, single photon emission computed tomography, electrophysiological testing and CSF analysis. The clinical picture often shows spontaneous remission, but when overt neurological symptoms occur or become progressive, therapeutic interventions with high dose corticosteroids and cytotoxic agents, such as intravenous cyclophosphamide pulse therapy, may be indicated.

Primary Sjögren's syndrome with severe central nervous system disease

OBJECTIVE

Central nervous system (CNS) involvement in primary Sjögren's syndrome (pSS) is controversial with regard to frequency, significance, and etiology.

METHODS

We describe a young woman with pSS and severe CNS disease and review the literature on the pathophysiology, clinical significance, symptoms, diagnostic examinations, and treatment of CNS disease with concomitant pSS (CNS-SS).

RESULTS

Our patient with pSS had a 5-month history of benign lymphadenopathy and myositis, after which she developed severe CNS disease, vasculitic lesions on her hands, and a neurogenic bladder attributable to spinal cord involvement. The diagnosis was based on the clinical picture and the results of a brain magnetic resonance imaging (MRI) scan, electroencephalography (EEG), and cerebrospinal fluid (CSF) analysis. The disease did not respond to corticosteroids, but the administration of cyclophosphamide resulted in recovery. In the literature, the incidence of CNS-SS varies widely, from rare to incidence rates of 20% to 25%. The clinical picture is diverse, ranging from mild cognitive symptoms to fatal cerebrovascular accidents. The pathophysiology of CNS-SS is unclear, specific diagnostic methods are not available, and diagnosis is based on the clinical picture and a combination of examinations. MRI is the most sensitive test and cerebral angiography the most specific. CSF reflects involvement of the leptomeninges, and EEG is nonspecific. There are no controlled studies of the treatment of CNS-SS. Regimens for vasculitis are commonly used.

CONCLUSIONS

CNS-SS is uncommonly recognized and difficult to diagnose. Increasingly accurate and available diagnostic examinations will yield more information about the association of CNS disease with pSS.

Neurobehavioral alterations in autoimmune mice

Inbred MRL, NZB and BXSB strains of mice spontaneously develop a systemic, lupus-like autoimmune disease. The progress of autoimmunity is accompanied with a cascade of behavioral changes, most consistently observed in tasks reflective of emotional reactivity and the two-way avoidance learning task. Given the possibility that behavioral alterations may reflect a detrimental consequence of autoimmune-inflammatory processes and/or an adaptive response to chronic malaise, they are tentatively labeled as autoimmunity-associated behavioral syndrome (AABS). It is hypothesized that neuroactive immune factors (pro-inflammatory cytokines, brain-reactive antibodies) together with endocrine mediators (corticotropin-releasing factor, glucocorticoids) participate in the etiology of AABS. Since AABS develops natively, and has a considerable face and predictive validity, and since the principal pathway to autoimmunity is known, AABS may be a useful model for the study of CNS involvement in human autoimmune diseases and by extension, for testing autoimmune hypotheses of several mental disorders (major depression, schizophrenia, Alzheimer's disease, autism and AIDS-related dementia).

Immunocytochemical detection of anti-hippocampal antibodies in Alzheimer's disease and normal cerebrospinal fluid

Immunocytochemical staining was performed to investigate the presence of anti-hippocampal antibodies in cerebrospinal fluid (CSF) from patients with probable Alzheimer's disease (AD) (n = 19), aged normal controls (n = 9), and young normal controls (n = 10). Marked staining of neurons in the granule cell layer of the dentate gyrus and in pyramidal neurons in CA1-3 of the rat hippocampus was observed in 5 AD CSF samples (26%), 1 aged control sample (11%), and 1 young control sample (10%). These differences were not statistically significant. One of the immunoreactive AD CSF specimens also contained high concentrations of C5b-9, the membrane attack complex. The infrequent occurrence of anti-hippocampal antibodies in AD CSF, and the detection of similar immunoreactivity in control CSF specimens, suggest that these antibodies are unlikely to play a role in the neurodegenerative process in most individuals with AD. However, elevated C5b-9 concentration in an AD CSF specimen with marked immunoreactivity to hippocampal neurons suggests the possibility that anti-neuronal antibodies may contribute to complement activation in some AD patients.

Primary systemic Sjögren syndrome (SS) preceding systemic lupus erythematosus: a retrospective study of 4 cases in a cohort of 55 SS patients

That SS and SLE can coexist is well established. The time relationship between the two diseases is however not well known. To determine whether SS can precede SLE, we reviewed the charts of 55 patients with SS diagnosed in our department between 1975 and 1985. All 55 patients fulfilled at least four of the six preliminary criteria for SS developed by the European Study Group for SS. At entry, none met four ARA criteria for SLE and none had anti-double-stranded DNA or anti-Sm antibodies. The mean follow-up was 12 years (range 8-18 years). Four of the 55 patients developed SLE (7.5%). High titres of anti-native DNA antibodies (> 35 IU RIA, normal < 7 IU) appeared in four patients (2-11 years after the diagnosis of SS). Two of these patients fulfilled at least four ARA criteria for SLE; two others had only three criteria. Two additional patients developed anti-Sm antibodies without anti-native DNA antibodies 1 and 10 years after the initial diagnosis of SS, respectively. Both patients fulfilled six ARA criteria for SLE. At entry, anti-SSA and/or anti-SSB antibodies were present in all six SS patients and persisted subsequently. The main clinical events suggesting progression to SLE were pleuropericarditis, glomerulonephritis and focal central nervous system disease. In conclusion, SS with extraglandular components can antedate SLE by many years. Anti-native-DNA and anti-Sm antibodies should be measured when atypical clinical manifestations occur in a patient with systemic SS.