Identification of transitional type II B cells in the salivary glands of patients with Sjögren's syndrome.

OBJECTIVE: To identify B cell subpopulations participating in the lymphocyte infiltrate of salivary glands from patients with primary Sjögren's syndrome. A special emphasis was placed on those B lymphocytes included in the ectopic germinal centers (GCs). METHODS: The presence of B cells in salivary glands and their polyclonality were ascertained by phenotyping and reverse transcription-polymerase chain reaction in salivary gland samples from 18 patients. Their phenotype was thoroughly analyzed using a number of double-staining combinations. The results obtained in tissue sections were confirmed by fluorescence-activated cell sorting analysis of B cells eluted from salivary glands, and these findings were compared with those in tonsils. RESULTS: Memory-type B cells were defined as CD20+, CD27+ and were seen in all specimens, whereas GCs were found in only 7 specimens. Furthermore, B cells found in these GCs lacked certain characteristics of centroblasts and centrocytes. Instead, they fulfilled the criteria for transitional type II (TII) B cells and resembled marginal-zone B cells. BAFF (the assistance of which is required for proper transformation of transitional TI B cells into transitional TII B cells) accumulated adjacent to transitional and marginal-zone-like B lymphocytes. Further evidence for the involvement of BAFF came from the expression of its receptors on infiltrating B cells. CONCLUSION: These transitional TII and marginal-zone-like B cells are probably instrumental in the local production of autoantibodies and possibly influential in the ensuing destruction of epithelial cells.

Is periodontal disease mediated by salivary BAFF in Sjögren's syndrome?

OBJECTIVE: To correlate the periodontal status of 15 patients with primary Sjögren's syndrome (SS) with their salivary levels of BAFF. METHODS: The periodontal status of 15 patients who fulfilled the criteria for primary SS was compared with that of 15 controls with xerostomia who did not fulfill the criteria for primary SS but had similar symptoms of dry mouth. The level of BAFF was measured in paired samples of saliva and serum using in-house enzyme-linked immunosorbent assays. Periodontitis was assessed by the plaque index, the modified gingival index, the papillary bleeding index, and the periodontal pocket depth. RESULTS: Notwithstanding the better oral hygiene practices of the patients with primary SS compared with those of the xerostomia controls and the subsequent reduction of their plaque index scores, complications of periodontitis, such as bleeding, gingival hypertrophy, and periodontal pockets, were not improved. This failure to ameliorate the complications of periodontitis in patients with primary SS was associated with high levels of BAFF in their saliva compared with the levels in xerostomia controls (7.4 +/- 2.1 versus 1.0 +/- 0.4 ng/ml [P < 0.002]). The levels of BAFF in saliva did not correlate with the levels in sera but did correlate with the periodontal pocket depth (P < 0.002). CONCLUSION: These findings are similar to the bone resorption observed in patients with rheumatoid arthritis. They suggest that the known effect of B cells in periodontitis would be partly mediated by salivary BAFF in patients with primary SS.

Thyroid dysfunction in primary Sjögren's syndrome: a long-term followup study.

OBJECTIVE: To evaluate the prevalence of thyroid dysfunction and related autoantibodies in patients with primary Sjögren's syndrome (pSS), and to determine whether these abnormalities develop over time. METHODS: pSS patients (n = 137) and controls (n = 120) were investigated for thyroid dysfunction and for the presence of anti-thyroid peroxidase antibody (anti-TPO) and antithyroglobulin antibody (ATG). Followup time for patients was 1-16 years, and 72 of the 120 controls were reevaluated 3 years after initial evaluation. RESULTS: Thyroid disease was more frequent in the pSS patients than in the controls (30% versus 4%; P < 10(-4)), as were anti-TPO and ATG (11% versus 3%; P < 0.02, and 3% versus 1%, not significant). Ten of 107 euthyroid pSS patients dropped out of the study, and thyroid dysfunction became apparent at followup in 12 of the remaining 97. Most of the patients with thyroid-related autoantibodies at entry developed autoimmune thyroid disease thereafter. CONCLUSION: Thyroid dysfunction is frequent in pSS patients, and those prone to develop thyroid disorders are identified by thyroid-related autoantibodies, or by rheumatoid factor and anti-Ro/SSA activity.

[Amyloidosis and aging]. / Amylose et vieillissement.

Amyloidosis is a heterogeneous group of extracellular protein deposition diseases. Age-related amyloidosis may be systemic or localized. The systemic forms include associated-myeloma AL amyloidosis and senile systemic amyloidosis which is the only clear-cut systemic form related to age and derived from normal transthyretin. In localized amyloidosis, the fibril protein precursors are synthesized in the tissue involved by the amyloid. In most cases, localized age-related amyloidosis does not appear to cause clinical disease with the exception of amyloid associated with Alzeihmer's disease and type 2 diabetes mellitus. The significance of aortic amyloidosis, amyloidosis of seminal vesicles, amyloid of the endocrine glands, and articular amyloidosis remains unknown.

Pathogenic effects of anti-Fc gamma receptor IIIb (CD16) on polymorphonuclear neutrophils in non-organ-specific autoimmune diseases.

The receptors FcgammaRIIIb and FcgammaRIIa for the Fc portion of IgG are naturally expressed in polymorphonuclear neutrophils (PMN). Autoantibodies (Ab) against FcgammaRIIIb exist in patients with non-organ-specific disease. These may be categorized, based on the results of an indirect immunofluorescence (IIF) test for the detection of anti-membrane-bound FcgammaRIIIb autoAbs, and an enzyme-linked immunosorbent assay for that of soluble FcgammaRIIIb-recognizing autoAbs. The IIF+ autoAbs are not cytotoxic, and prolong the survival of the cells. The autoAb-triggered anti-apoptotic signal may be transduced through FcgammaRIIa and/or CD11b, the beta-chain of the neighboring complement receptor type 3. However, FcgammaRIIIb appears to be as competent as FcgammaRIIa, because the results obtained using the respective monoclonal Abs are additive. Soluble FcgammaRIIIb binds to CD11b and produces similar effects, suggesting that autoAb-stimulated FcgammaRIIIb can work in concert with CD11b. Anti-FcgammaRIIIb-conditioned supernatant of PMNs induces the transcription of messenger RNA for granulocyte colony-stimulating factor (CSF) and granulocyte-macrophage CSF, followed by the release of these anti-apoptotic factors. The delay in apoptosis is accompanied by a down-regulated expression of Bax. Thus, apoptosis of aged PMNs can be modulated by signaling through FcgammaRIIIb, which may occur in patients with PMN-binding anti-FcgammaRIIIb autoAbs.