Sialochemistry in Sjögren's syndrome: a review

Urban legends series: Sjögren's syndrome

Sjögren's syndrome (SjS) is one of the most common autoimmune rheumatic diseases, clinically characterized by xerostomia and keratoconjunctivitis sicca. We investigated the following controversial topics: (i) Do we have reliable ways of assessing saliva production? (ii) How important are the quantity and quality of saliva? (iii) Are only anti-SSA/Ro and anti-SSB/La relevant for the diagnosis of SjS? (iv) Are the American-European Consensus criteria (AECC) the best way to diagnose SjS? Results from literature searches suggested the following: (i) Despite the fact that numerous tests are available to assess salivation rates, direct comparisons among them are scarce with little evidence to suggest one best test. (ii) Recent developments highlight the importance of investigating the composition of saliva. However, more research is needed to standardize the methods of analysis and collection and refine the quality of the accumulating data. (iii) In addition to anti-Ro/La autoantibodies, anti α-fodrin IgA and anti-MR3 autoantibodies seem to be promising diagnostic markers of SjS, but more studies are warranted to test their sensitivity and specificity. (iv) AECC are classification, not diagnostic criteria. Moreover, recent innovations have not been incorporated into these criteria. Consequently, treatment directed to patients diagnosed using the AECC might exclude a significant proportion of patients with SjS.

Progression of salivary gland dysfunction in patients with Sjogren's syndrome

BACKGROUND

Salivary gland dysfunction is one of the key manifestations of Sjögren's syndrome.

OBJECTIVES

(1) To assess prospectively loss of function of individual salivary glands in patients with primary and secondary Sjögren's syndrome in relation to disease duration and use of immunomodulatory drugs. (2) To study changes in sialochemical and laboratory values and subjective complaints over time.

METHODS

60 patients with Sjögren's syndrome were included in this study. Whole and gland-specific saliva (parotid and submandibular/sublingual (SM/SL)), samples were collected at baseline and after a mean of 3.6 (SD 2.3) years of follow-up. Disease duration was recorded for all patients.

RESULTS

Patients with Sjögren's syndrome with short disease duration had significantly higher stimulated flow rates at baseline than those with longer disease duration (p<0.05). When compared with healthy controls, the decrease in SM/SL flow rates at baseline was more prominent than that in parotid flow rates (p<0.05). Over time, there was a significant further decrease of stimulated flow rates, especially of the parotid gland, accompanied by increasing problems with swallowing dry food (p<0.05). The decrease was independent of the use of corticosteroids or disease-modifying antirheumatic drugs (DMARDs). Sialochemical variables remained stable.

CONCLUSIONS

Early Sjögren's syndrome is characterised by a decreased salivary gland function (parotis>SM/SL), which shows a further decrease over time, regardless of the use of DMARDs or steroids. Patients with Sjögren's syndrome with longer disease duration are characterised by severely reduced secretions of both the parotid and SM/SL glands. These observations are relevant for identifying patients who would most likely benefit from intervention treatment.

Oral health condition and saliva flow in southern Chinese with Sjögren’s syndrome

OBJECTIVE

To investigate the oral health condition and saliva flow of southern Chinese patients with Sjögren's syndrome (SS).

METHOD

51 SS patients (26 primary and 25 secondary cases) and 29 controls took part in this cross-sectional study. Stimulated whole and parotid saliva flow rates, pH, and buffer capacity, and xerostomia, oral mucosal lesions, oral hygiene status, dental and periodontal conditions, prosthetic status were assessed and compared between groups.

RESULTS

Stimulated whole saliva (SWS) flow was reduced in primary and secondary SS cases (p<0.001), pH and buffer capacity were also reduced in the primary SS group (p<0.05). SS patients had a greater prevalence of xerostomia than controls (p<0.001). Primary SS patients had a higher mean DMFT, more missing teeth, and more prostheses than secondary SS cases and controls (p<0.05). SWS flow correlated negatively with the number of filled teeth in both SS groups (p<0.05) and the number of decayed teeth in the primary SS group (p<0.05).

CONCLUSION

Despite good oral hygiene and regular dental check-ups, the oral health of southern Chinese with primary SS was significantly compromised compared with secondary SS cases and controls, most probably due to the combined effect of impaired salivary gland function and poorer saliva buffer capacity.

Salivary and serum beta2-microglobulin and gamma-glutamyl-transferase in patients with primary Sjögren syndrome and Sjögren syndrome secondary to systemic lupus erythematosus

BACKGROUND

Sialochemistry has been proposed as a simple and useful tool for the diagnosis of Sjögren syndrome (SS). Although many changes have been detected in several constituents of saliva from patients with SS, none are individually sensitive or specific enough for diagnosing SS. The aim of this study was to assess the value of the combined determination of beta2-microglobulin (beta2m) and gamma-glutamyl-transferase (GGT) activity in serum and saliva as a diagnostic instrument for differentiating primary and secondary [to systemic lupus erythematosus (SLE)] SS patients from normal subjects.

METHODS

Nineteen primary SS (pSS) patients, 15 patients with SS secondary to SLE, and 25 SLE patients without SS were studied. Thirty healthy subjects were included in the study as control group.

RESULTS

By means of a mathematical model, (a) 84.1%, (b) 85.7%, and (c) 87.0% of patients were correctly classified as SS or normal when (a) salivary beta2m and GGT values, (b) serum beta2m and salivary GGT values, and (c) salivary beta2m and GGT along with serum beta2m values, respectively, were considered. To differentiate between pSS and sSS by means of the mathematical model, the combination of serum beta2m and salivary GGT values achieved that 81.8% of the patients were correctly classified.

CONCLUSION

Since sialochemistry is an easy, safe and reliable test, the combined determination of beta2m and GGT in saliva and serum was useful for differentiating SS patients from normal subjects, but not excessively good for differentiating pSS from sSS patients.

The diagnostic applications of saliva--a review

This review examines the diagnostic application of saliva for systemic diseases. As a diagnostic fluid, saliva offers distinctive advantages over serum because it can be collected non-invasively by individuals with modest training. Furthermore, saliva may provide a cost-effective approach for the screening of large populations. Gland-specific saliva can be used for diagnosis of pathology specific to one of the major salivary glands. Whole saliva, however, is most frequently used for diagnosis of systemic diseases, since it is readily collected and contains serum constituents. These constituents are derived from the local vasculature of the salivary glands and also reach the oral cavity via the flow of gingival fluid. Analysis of saliva may be useful for the diagnosis of hereditary disorders, autoimmune diseases, malignant and infectious diseases, and endocrine disorders, as well as in the assessment of therapeutic levels of drugs and the monitoring of illicit drug use.

Sialometry and sialochemistry: a non-invasive approach for diagnosing Sjögren's syndrome

BACKGROUND

Analysis of salivary variables has frequently been proposed as a diagnostic tool for Sjögren's syndrome (SS). Because univocal salivary reference values are lacking, it is currently rather difficult to use sialometry and sialochemistry for diagnosing SS unless major changes have occurred in salivary secretion and composition.

OBJECTIVE

To define reference values of several salivary variables, which offer a possible new and non-invasive means of diagnosing SS.

METHODS

Cut off points were selected from receiver operating characteristic curves of gland-specific sialometrical and sialochemical variables, which have proved to be potentially relevant for diagnosing SS in a previous study-that is, sodium, chloride, and phosphate concentration in stimulated parotid and submandibular/sublingual (SM/SL) saliva, unstimulated and stimulated SM/SL flow rates, and lag phase of parotid secretion, respectively. By combining the most discriminating variables, two different diagnostic approaches for SS were applied in a group of 100 patients and subsequently evaluated in a second group of 20 patients. The first approach was to combine variables by applying their cut off points into sets of criteria for a positive diagnosis of SS. The second approach was to construct a logistic regression model that predicts the true state of a patient (SS or non-SS). From both approaches, the tests with highest likelihood ratio combined with the smallest number of rejected cases were selected for clinical use.

RESULTS

The most accurate test combined the stimulated SM/SL flow rate and parotid sodium and chloride concentration as salivary variables for diagnosing SS; it had a sensitivity of 0.85 and a specificity of 0.96. The selected tests proved equally accurate in the second group of patients.

CONCLUSIONS

Because the proposed non-invasive diagnostic tools can be easily applied, do not need a laboratory other than for routine blood testing, and are very accurate, gland-specific sialometry and sialochemistry may eventually replace other, more invasive, diagnostic techniques for diagnosing SS.

Lactoferrin, amylase and mucin MUC5B and their relation to the oral microflora in hyposalivation of different origins

There are several reasons for hyposalivation, each affecting the salivary composition in different ways. The aim of this study was to analyze and compare lactoferrin, amylase and mucin MUC5B in stimulated whole saliva collected from subjects with hyposalivation of different origins and to relate the results to the presence of some microbial species associated with oral disorders. Albumin was determined as a marker of serum leakage. The characteristic feature for subjects with radiation-induced hyposalivation was a large increase in lactoferrin, probably due to leakage through inflamed mucosal tissues, while it was a high albumin content for the group with primary Sjögren's syndrome, probably due to disruption of the fragile mucosa. The saliva composition in subjects with hyposalivation of unknown origin or due to medicines was close to that in the healthy controls. All three hyposalivation groups tended to display a decrease in the concentrations of MUC5B and amylase. None of the microbial species analyzed (streptococci, mutans streptococci, Lactobacillus spp., Fusobacterium nucleatum, Prevotella intermedia/Prevotella nigrescens, Candida albicans, Staphylococcus aureus and enterics) correlated with concentration of MUC5B in saliva. The RT group, having the highest concentration of lactoferrin, had the lowest median number of F. nucleatum and was the only group in which median number of P. intermedia/P. nigrescens was zero.

Sialometry and sialochemistry: diagnostic tools for Sjögren's syndrome

BACKGROUND

The common occurrence of xerostomia in Sjögren's syndrome (SS) as well as the easy accessibility of saliva supports the use of sialometry and sialochemistry in the diagnosis of SS. Collection and analysis of whole saliva (oral fluid) is currently the routine technique for sialometry, despite the fact that it is rather inaccurate and impure.

OBJECTIVE

To assess the value of glandular sialometry and sialochemistry as diagnostic instruments in SS.

METHODS

In a group of 100 consecutive patients referred for diagnosis of SS, glandular secretory flow rates and a spectrum of salivary components (sodium, potassium, chloride, calcium, phosphate, urea, amylase, total protein) were assessed. The patients were classified as positive or negative for SS according to the revised European classification criteria.

RESULTS

Patients with SS differed clearly from those who tested negative for SS, showing lower submandibular/sublingual (SM/SL) flow rates and an appreciably changed salivary composition of parotid and SM/SL saliva. Besides changes in salivary flow rate and composition, distinct sialometric profiles were observed, characteristic of either early or late salivary manifestation of SS, or of the xerogenic side effects of medication.

CONCLUSIONS

Glandular sialometry and sialochemistry are not only useful tools for differentiating SS from other salivary gland disease in clinical practice, but they also have great potential as diagnostic criteria for SS, showing distinct sialometric and sialochemical changes as well as profiles. Being simple, safe (non-invasive), and sensitive (early disease detection), they have three major advantages over other oral tests for SS.

Primary Sjögren's syndrome: oral aspects on pathogenesis, diagnostic criteria, clinical features and approaches for therapy

Primary Sjögren's syndrome (pSS) is a chronic inflammatory systemic autoimmune disease affecting the exocrine glands and predominantly the salivary and lacrimal glands. The impaired gland function is assumed to be a result of progressive lymphocyte-mediated destruction of the exocrine gland tissue leading to the cardinal manifestations, hyposalivation and keratoconjunctivitis sicca (KCS), as well as devastating symptoms of oral and ocular dryness. Although primarily characterised as an exocrine dysfunction, non-exocrine organs may also be affected. The onset and course of pSS is usually insidious but may develop into a disabling disease, which profoundly affects the patient's general well being and quality of life. Moreover, pSS may even evolve into a lymphoid malignancy. The aetiology of pSS remains unknown but the pathogenesis of exocrine cell damage is apparently multi-factorial, including immunological, genetic, hormonal and viral components. Recent research also includes neurogenic aspects of exocrine gland dysfunction, including the interference of immune mediators with glandular response to neurotransmitters released from nerve fibres. pSS usually affects middle-aged women and the female:male ratio is 9:1. The prevalence varies from 0.29-4.8%, depending on the population sampled and the diagnostic criteria used. At present, there are no specific diagnostic tests for pSS and no universally accepted diagnostic criteria. The current therapy is primarily symptomatic. This review focuses on the current oral clinical, diagnostic, pathogenic and therapeutic aspects of pSS.

Immunohistochemical detection of insulin-like growth factor-I in the labial salivary glands of patients with Sjögren's syndrome

OBJECTIVE

The purpose of the present study was to investigate the presence of insulin-like growth factor-I (IGF-I) in the labial salivary glands of patients with Sjögren's syndrome and healthy controls and to determine if there are any differences between these two groups.

DESIGN

An immunohistochemical study.

SUBJECTS AND METHODS

Twenty-five patients with Sjögren's syndrome, 20 healthy controls and 20 patients with mucoceles of the lip were used in this study. All individuals underwent a systemic evaluation and a lip biopsy. Sections from the lip biopsies were stained with haematoxylin and eosin (H&E). Immunohistochemical staining was also performed using a three-step indirect immunoperoxidase for IGF-I.

RESULTS

The light microscopic examination revealed the presence of a mononuclear infiltration in the labial salivary glands of patients with Sjögren's syndrome. Most of the infiltrates were lymphocytes. Immunohistochemically an intense staining result was apparent in the same group. In contrast sections of labial salivary glands of healthy individuals and of patients with mucoceles revealed very weak staining.

CONCLUSIONS

The above findings and the fact that both lymphocytic infiltration and IGF-I were predominantly seen in ductal regions, suggest that IGF-I may be a target of autoimmunity in Sjögren's syndrome.

Lectin binding studies of parotid salivary glycoproteins in Sjögren's syndrome

Human parotid salivas were collected from patients with secondary Sjögren's syndrome and controls without disease or with drug-induced xerostomia. Parotid glycoproteins were separated by gradient sodium dodecyl sulphate gel electrophoresis (SDS-PAGE), electroblotted onto nitrocellulose membrane and probed with biotinylated lectins of characterised sugar specificities. The binding patterns of lectins from Maclura pomifera (MPA) and Arachis hypogaea (PNA) indicated that many parotid glycoproteins have sialylated O-linked glycans and that sialylation is not affected by disease. Binding by lectins from Ricinus communis (RCA-1), Limax flavus (LFA), Lotus tetragonolobus (LTA) and Ulex europaeus (UEA-1) appeared unaltered in secondary Sjögren's syndrome, suggesting no obvious change in N-glycosylation of parotid glycoproteins. Variations in binding patterns of most lectins was attributable to subject-to-subject variations in recognised polymorphic proteins. Dolichos biflorus agglutinin (DBA) consistently showed increased binding to a 75 kDa (Mr) protein in salivas from patients with secondary Sjögren's syndrome. The binding protein was identified as lactoferrin but found not to contain N-acetylgalactosamine, the sugar to which DBA binds. Binding of DBA to lactoferrin was dependent upon its saturation with iron, modified SDS-PAGE under nonreducing conditions resolved iron-free and iron-saturated lactoferrins and demonstrated increased levels of the iron-saturated form in secondary Sjögren's syndrome. Lectin binding studies of purified lactoferrins from saliva, milk, and polymorphonuclear neutrophils suggested that raised levels of lactoferrin in saliva originate from salivary cells and not from inflammatory cells. These results suggest that DBA binding provides greater specificity as an indicator of salivary gland disease than measurement of lactoferrin levels alone.

Primary Sjögren's syndrome: salivary gland function and clinical oral findings

OBJECTIVE

To evaluate salivary gland function, saliva composition and oral findings in patients with primary Sjögren's syndrome (pSS) subdivided into patients with and without focus score > or = 1 (FS) and/or antibodies to SSA/SSB (AB) as well as in healthy controls.

SUBJECTS AND METHODS

Unstimulated (UWS) and chewing stimulated (SWS) whole saliva, and stimulated parotid saliva (SPS) were collected in 16 patients fulfilling the European classification criteria for pSS subdivided into those with FS and/or AB (n = 8) and those without FS and AB (n = 8), and in age-matched (n = 14) and young healthy controls (n = 13). UWS and SWS were analysed for Na+ and K+. SPS was analysed for Na+, K+, statherin, and proline-rich proteins (PRPs). Sicca symptoms, DMFT/DMFS, plaque (PI) and gingival (GI) scores, periodontal pocket depth (PPD), and mucosal status were recorded.

RESULTS

The young healthy controls had lower UWS as compared to the aged controls (P = 0.03). However, the aged controls had higher DMFT/DMFS (P < 0.001) and PI, GI and PPD (P < 0.01). Patients with FS and/or AB generally had lower saliva secretory rates than patients without FS and/or AB (P = 0.01 for UWS and SPS) and age-matched healthy controls (P = 0.001). There was no significant difference in the content of Na+ and K+, statherin and PRPs between groups. Patients with FS and/or AB had the highest frequency of oral mucosal changes and higher DMFT/DMFS than patients without FS and/or AB and healthy controls (P < 0.01). However, PI, GI, and PPD did not differ significantly.

CONCLUSION

Patients with FS and/or AB had lower salivary secretory rates, higher DMFT/DMFS, and more oral mucosal changes than patients without FS and/or AB. Additionally, data suggest that salivary gland function in healthy individuals do not decrease with age.

Standardized assessment of disease status in patients with primary Sjögren's syndrome: the foundation for creating criteria for disease activity and damage?

Primary Sjögren's syndrome (pSS) is increasingly acknowledged as a disease entity with consistent pathogenesis and clinical presentation. This has encouraged proposals for uniform nomenclature, as well as for classification of disease subsets and clinical disease manifestations. The purpose of this literature survey is to analyse present pathogenetic and clinical data on pSS from the viewpoint of their usability for developing criteria for activity and damage. It appears that the routinely used tests for evaluating clinical disease manifestations in pSS probably measure both activity and damage. Moreover, no immunopathogenic marker has been shown to adequately represent all aspects of disease activity in pSS. The survey demonstrates the need for longitudinal studies in which potential markers of disease activity and damage are validated.

Indicators of salivary gland inflammation in primary Sjogren's syndrome

The aim of this study was to establish additional indicators in saliva and plasma which are associated with salivary gland inflammation in patients with primary Sjögren's syndrome (SS). ELISA assays were used to determine the concentrations of sICAM-1, sVCAM-1, sIL-2R alpha, IgA, IgG, calprotectin and albumin in parotid saliva, whole saliva and plasma samples. Soluble ICAM-1 was present in whole and parotid saliva samples from primary SS patients. Soluble VCAM-1 and sIL-2R alpha could not be detected in salivary samples from either primary SS or control subjects. IgA, IgG, calprotectin and albumin concentrations were higher in both whole and parotid saliva in the patient group compared with the control group. The results showed increased levels of calprotectin in all saliva samples compared to plasma, suggesting that calprotectin may be locally produced. Increased plasma values of sICAM-1, sVCAM-1, sIL-2R alpha, IgA, IgG and calprotectin were detected in primary SS patients when compared to controls. The output/min of IgA, IgG, calprotectin and albumin was decreased in SS patients. Plasma levels of various proteins could offer information concerning glandular and extraglandular inflammatory processes. However, salivary levels of these proteins (particularly sICAM-1) tend to reflect more the local inflammatory activity, providing a convenient and non-invasive tool for diagnosis.

Tear and saliva ferning tests in Sjögren's syndrome (SS)

The purpose of this study was to evaluate the tear ferning test (TFT) and the saliva ferning test (SFT) as diagnostic tests for xerophthalmia and xerostomia respectively in patients with SS. Dried samples of freshly produced tears and saliva from: (A) 36 healthy controls without sicca symptoms, (B) 61 patients with primary SS, (C) 53 patients with secondary SS and (D) 22 patients with psychiatric disorders receiving antidepressants, were examined by polarizing light microscopy. All individuals included in the study were postmenopausal women. The crystallization was classified into 4 types according to the ferning phenomenon: uniformity, branching, spreading and integrity (type I normal and II, III, IV abnormal). Abnormal TFT was found in tear samples of: (A) 8/72 normal control eyes, (B) 110/122 prim SS eyes, (C) 86/106 sec SS eyes and (D) 30/44 psychiatric patients' eyes. Abnormal SFT was found in: (A) 6/36 of normal controls, (B) 59/61 of prim SS, (C) 51/53 of sec SS patients and (D) 16/22 of psychiatric patients. The differences of both TFT and SFT of patients with prim SS and sec SS versus controls were significant (p < 0.001). The sensitivity of TFT was found to be high both in prim SS (90%) and in sec SS (81%). In addition the specificities of TFT and SFT were high 89% and 83% respectively. On the other hand the differences of TFT and SFT in psychiatric patients receiving antidepressants versus normal controls were also significant (p < 0.05 and p < 0.025 respectively). According to our data TFT and SFT are simple, sensitive and specific tests to evaluate xerophthalmia and xerostomia in SS and probably in other conditions characterized by mucous membrane dryness.

Salivary beta 2-microglobulin in NZB/WF1 mice

Unstimulated parotid and submandibular/sublingual saliva from New Zealand black/WF1 (NZB/WF1) mice as collected by microcapillary (1 microliter), and the content of beta 2-microglobulin (beta 2-MG) determined by a sandwich enzyme immunoassay. Salivary beta 2-MG contents of control C57BL/6 and NZB/WF1 mice (45 weeks of age) were 0.68 +/- 0.18 micrograms/ml and 1.42 +/- 0.21 micrograms/ml (mean +/- SD), respectively, from the parotid gland and 0.62 +/- 0.17 micrograms/ml and 1.34 +/- 0.21 microliters/ml, respectively, from the submandibular sublingual glands. However, the concentration of beta 2-MG was not increased in the NZB/WF1 mice at 5 and 20 weeks of age. Saliva from NZB/WF1 mice (45 weeks old) was fractionated by micro two-dimensional gel electrophoresis; it exhibited both qualitative and quantitative changes in protein composition in comparison to the two-dimensional at 5 weeks of age. These observations parallel those in saliva from patients with Sjögren's syndrome.

Increased beta 2-microglobulin in both parotid and submandibular/sublingual saliva from patients with Sjögren's syndrome

Samples of unstimulated saliva from patients with sialoadenopathy were collected by microcapillary tube (1 microliter), and their beta 2-microglobulin (B2-MG) content determined by a sandwich enzyme immunoassay. A higher than normal (control) concentration of the globulin was present in both parotid and submandibular/sublingual saliva from the patients with Sjögren's syndrome but not in the samples from the patients with sialoadenitis or diabetes mellitus. The increase in B2-MG in saliva from patients with Sjögren's syndrome may reflect that immunolopathological events are important in the degeneration of both glands in this disease. Therefore, the determination of B2-MG in saliva may be a simple, non-invasive technique for confirming the diagnosis of Sjögren's syndrome as an autoimmune disease.

Two-dimensional electrophoresis of human salivary proteins from patients with sialoadenopathy

Unstimulated saliva was fractionated by micro two-dimensional gel electrophoresis, and the proteins visualized by silver staining and immunostaining. The subjects with Sjögren's syndrome exhibited both quantitative and qualitative alterations in the protein composition of the saliva not only from the parotid gland but also from the submandibular/sublingual glands.

Whole saliva in systemic lupus erythematosus patients

Whole saliva composition and flow rate were examined in 22 patients with systemic lupus erythematosus and compared with matched healthy controls. Significantly lowered salivary flow rate was observed in patients with systemic lupus erythematosus unrelated to the subjective complaint of xerostomia. Salivary sodium, calcium, and magnesium concentrations were significantly higher in the SLE patients with systemic lupus erythematosus, whereas potassium and total protein concentrations and amylase activity did not differ significantly from the controls. Salivary IgA and IgM levels were significantly higher in the patients than in controls. IgA, IgG, IgM, C3, C4, antinuclear antibody, and anti-DNA antibody levels were measured in serum of the patients with systemic lupus erythematosus and correlated with salivary immunoglobulins. The only significant correlation between saliva and serum was found between levels of salivary IgG and serum anti-DNA antibody. The altered salivary composition might indicate a subclinical involvement of salivary glands in the patients.

The diagnostic value of salivary fluid levels of beta 2-microglobulin, lysozyme and lactoferrin for primary Sjögren's syndrome

In search of a simple non-invasive diagnostic test for primary Sjögren's syndrome (SS) the concentration of beta 2-microglobulin (beta 2-m), lysozyme (LZM) and lactoferrin (Lf) was measured in stimulated parotid saliva of 39 patients with primary SS, 42 patients suspected of the syndrome in whom the diagnosis could be excluded (NON-SS) and in 41 normal control individuals. Salivary fluid levels of beta 2-m, LZM and Lf exceeding the mean + 2 x standard deviation of healthy control values were found in respectively 58%, 23%, and 26% of the primary SS patients and in 7%, 11% and 0% of the NON-SS patients. The results of this study indicate that due to the low sensitivity the tests are not suitable as a screening procedure for patients suspected of having primary SS. However, measurement of beta 2-m in stimulated parotid saliva may be used as an adjunctive diagnostic test for primary SS.

Primary Sjögren's syndrome--clinical and laboratory markers of disease activity

Primary Sjögren's syndrome is a chronic autoimmune disorder of the lacrimal and salivary glands, reflecting general involvement of the exocrine tissues and leading to functional impairment. This polyglandular disease is often associated with systemic extraglandular manifestations, and laboratory tests usually indicate polyclonal B-lymphocyte hyperactivity. Clinical and laboratory markers monitoring the disease processes are needed for improved management of primary Sjögren's syndrome. However, incomplete knowledge of the long-term course of inflammation as well as of clinical manifestations makes precise and simple directions for monitoring disease activity in primary Sjögren's syndrome difficult. This review describes potential primary (eg, salivary gland histopathology, autoantibodies, soluble interleukin-2 receptors, and beta 2-microglobulin) and secondary disease activity markers (clinical and laboratory signs of glandular and extraglandular organ damage) and their known associations. The importance of genetic characteristics, patient age, and symptom duration for the disease activity markers is indicated. The systematic use of primary and secondary disease activity markers will improve our understanding of primary Sjögren's syndrome and help create better guidelines for monitoring the disease.

Beta 2 microglobulin in tear fluid from patients with primary Sjögren's syndrome

beta 2 Microglobulin concentration in tear fluid was measured in 35 patients with primary Sjögren's syndrome (SS), in 28 normal control subjects matched for age and sex, and in 18 patients with arthralgias or myalgias and sicca complaints, in whom the diagnosis primary SS had been excluded. Increased beta 2 microglobulin concentrations were found in the patients with SS, but no correlation was found with the duration of the disease, age, or tear fluid production. Tear fluid beta 2 microglobulin determinations may be useful as an adjunctive diagnostic test for primary SS.