(Fig. 6.4). This pattern is not considered to be associated with primary SS and often progresses to glandular atrophy and xerostomia.

6.3.1.2 Ectopic Germinal Center Formation

Germinal centers (GCs) were deÞned as wellcircumscribed inßammatory foci containing at least 50 mononuclear cells, presenting with a dark and light zone, within otherwise normal salivary gland epithelium [44]. Densely packed proliferating cells (centroblasts) are localized in the dark zone. The dark zone is surrounded by the proposed GC light zone which is more richly supplied with follicular dendritic cells and less densely packed with cells (centrocytes) [46].

Such lymphoid neogenesis has previously described with the presence of ectopic follicles/GC in 20Ð25% of patients with SS [43Ð45, 47Ð49]. Similar features have been described in other autoimmune diseases such as rheumatoid arthritis (RA) [50], myasthenia gravis [51], multiple sclerosis [52], during chronic Helicobacter pylori infections in gastric mucosa [53], in chronic inßammatory disorders of the liver [54], Hashimotos disease [55], and in oral buccal mucosa related to amalgam Þllings and lichenoid reactions [56, 57].

Germinal center formation was investigated in more detail [48], and the contemporary existence of GC and focal interaction (FI) was disclosed. GCs were characterized by B-cell and T-cell organization, increased levels of proliferating cells, follicular dendritic cell networks, and the localization of plasma cells in a mantel zone-like area.

6.3.1.3 Clinical Implications of Ectopic Germinal Center Formation

By morphology, GC-like structures were detected in 47/169 of patients [44]. Focus score, IgG levels, and RF titres were elevated compared to the GC− patients. Mean unstimulated salivary ßow was reduced in the GC+ patients [44].

An association of GC development with increased risk of B-cell lymphomas has been

proposed [9], wherein formation of proliferating GCs were thought to contribute to malignant transformation and development of MALT lymphoma. The estimated life-time risk of lymphoma in SS has been estimated to be 5Ð10% [9, 11], but in general mortality is not signiÞcantly increased compared to the general population [58]. Patients with SS and chronic H. pylori infection are at increased risk for developing lymphomas, possibly related to prolonged lymphocytic activation in the target organ(s) of these patients [59, 60]. In a recent study, signiÞcant predictors of lymphoproliferative disease were purpura/skin vasculitis, low levels of complement factors C3/C4, CD4+ T lymphocytopenia and a low CD4+/CD8+ T-cell ratio [11, 61].

Results from Refs. [43, 44] indicate a certain clinical immunological phenotype for SS patients with ectopic lymphoid organization, which warrant further studies. Whether ectopic GC identiÞes patients at risk to develop lymphoma remains to be seen in prospective studies.

6.4Late Breaking Update

Several studies regarding histopathological features in the minor salivary glands have been published since the submission of this manuscript in late 2008 and its publishing in 2011. In this section we present some of these contributions.

Histopathological studies of the minor salivary glands have unraveled an interest in both the inÞltrating inßammatory cells and the salivary gland epithelium. Stromal changes such as fat/adipose tissue, both in the form of degenerative changes as a consequence of chronic Òburned outÓ inßammation [62] and as a possible source of chemokines [63] as resident adipocytes, expressed CXCL12 in the minor salivary glands of patients with pSS, possibly providing survival niches for long-lived plasma cells.

A recently published study [64] investigated lymphoid organization (Fig. 6.4) in labial salivary gland tissue biopsies available from two Swedish pSS patient cohorts (n = 175), by light microscopy in a blinded study in order to identify

GC-like structures as a sign of ectopic lymphoid tissue formation and organization. At diagnosis, 25% of pSS patients were found to have GC-like structures in their salivary glands, corresponding to previous [43Ð45, 48] and more recent Þndings in other cohorts [62, 65, 66]. Through a linkage study with the Swedish cancer registry 7 of 175 patients studied (14% of GC+ and 0.8% of GC-) went on to develop NHL in a total of 1855 patient years at risk, with a median onset of 7 years following the initial diagnostic salivary gland biopsy. Six of these seven patients had GClike structures at diagnosis; the remaining patient was GC negative at the time of diagnosis (p = 0.001). In a Greek study investigating major inÞltrating cells in salivary gland inÞltrates of various severity three of seven cases with lymphoma also presented with GC-like structures in the minor salivary glands (p = 0.005) [65].

In a Norwegian cohort of pSS (n = 141), interleukin (IL)-17, IL-1RA, IL-15, macrophage inßammatory protein 1 (MIP-1), eotaxin, interferon (IFN), and IL-4 levels were signiÞcantly increased in the 27 (23%) patients with ectopic germinal center formation (GC+) in the salivary glands compared with the GCpatients (n = 70). In addition, minor differences in cytokine levels were found when comparing age groups [62]. Increased titers of Th17-associated cytokines, IL17, IL-1, and the IL-23 subunit IL-12p40, were speculated to indicate a higher activity of these cells in GC+ patients.

Taken together, these Þndings indicate an important role for the minor salivary gland biopsy in the diagnostic evaluation for primary SjšgrenÕs syndrome Ð a highly predictive and easy to obtain marker for NHL development. Furthermore, such a marker may allow for risk stratiÞcation of patients and the possibility to initiate preventive B-cell directed therapy.

References

1.Seifert G, Sobin LH. Histological typing of salivary gland tumors. 2nd ed. Berlin: Springer; 1991, pp. 107Ð8.

2.Morgan WS, Castleman B. A clinicopathologic study of MikuliczÕs disease. Am J Pathol. 1953 MayJun;29(3):471Ð503.

3.Batsakis JG. The pathology of head and neck tumors: the lymphoepithelial lesion and SjšgrenÕs syndrome, Part 16. Head Neck Surg. 1982 Nov-Dec;5(2): 150Ð63.

4.Jonsson R, Kroneld U, Backman K, Magnusson B, Tarkowski A. Progression of sialadenitis in SjšgrenÕs syndrome. Br J Rheumatol. 1993 Jul;32(7):578Ð81.

5.Delaleu N, Jonsson MV, Jonsson R. Disease mechanisms of SjšgrenÕs syndrome. Drug Disco Today Disease Mech [Review]. 2004;1(3):329Ð36.

6.Anderson LG, Talal N. The spectrum of benign to malignant lymphoproliferation in SjšgrenÕs syndrome. Clin Exp Immunol. 1972 Feb;10(2):199Ð221.

7.Kassan SS, Thomas TL, Moutsopoulos HM, Hoover R, Kimberly RP, Budman DR, et al. Increased risk of lymphoma in sicca syndrome. Ann Intern Med. 1978 Dec;89(6):888Ð92.

8.Zulman J, Jaffe R, Talal N. Evidence that the malignant lymphoma of SjšgrenÕs syndrome is a monoclonal B-cell neoplasm. N Engl J Med. 1978 Nov 30;299(22):1215Ð20.

9.Voulgarelis M, Dafni UG, Isenberg DA, Moutsopoulos HM. Malignant lymphoma in primary SjšgrenÕs syndrome: a multicenter, retrospective, clinical study by the European Concerted Action on SjšgrenÕs Syndrome. Arthritis Rheum. 1999 Aug;42(8):1765Ð72.

10.Theander E, Henriksson G, Ljungberg O, Mandl T, Manthorpe R, Jacobsson LT. Lymphoma and other malignancies in primary SjšgrenÕs syndrome: a cohort study on cancer incidence and lymphoma predictors. Ann Rheum Dis. 2006 Jun;65(6): 796Ð803.

11.Ioannidis JP, Vassiliou VA, Moutsopoulos HM. Long-term risk of mortality and lymphoproliferative disease and predictive classiÞcation of primary SjšgrenÕs syndrome. Arthritis Rheum. 2002 Mar;46(3):741Ð7.

12.Vitali C, Bombardieri S, Jonsson R, Moutsopoulos HM, Alexander EL, Carsons SE, et al. ClassiÞcation criteria for SjšgrenÕs syndrome: a revised version of the European criteria proposed by the AmericanÐ European Consensus Group. Ann Rheum Dis. 2002 Jun;61(6):554Ð8.

13.Batsakis JG. Tumors of the head and neck: clinical and pathological considerations. 2nd ed. Baltimore, MD: Williams & Wilkins; 1979, pp. 105Ð12.

14.Waterhouse JP. Focal adenitis in salivary and lacrimal glands. Proc R Soc Med. 1963 Oct;56:911Ð8.

15.Waterhouse JP, Doniach I. Post-mortem prevalence of focal lymphocytic adenitis of the submandibular salivary gland. J Pathol Bacteriol. 1966 Jan;91(1): 53Ð64.

16.Scott J. The incidence of focal chronic inßammatory changes in human submandibular salivary glands. J Oral Pathol. 1976 Nov;5(6):334Ð46.

17.Klussmann JP, Wagner M, Guntinas-Lichius O, MŸller A. Detection of HHV-8 sequences and antigens in a MALT lymphoma associated with SjšgrenÕs syndrome. J Oral Pathol Med. 2003;32:243Ð5.

18.De Vita S, De Marchi G, Sacco S, Gremese E, Fabris M, Ferraccioli G. Preliminary classiÞcation of nonmalignant B cell proliferation in SjšgrenÕs syndrome: perspectives on pathobiology and treatment based on an integrated clinico-pathologic and molecular study approach. Blood Cells Mols Dis. 2001;27: 757Ð66.

19.Van Mello NM, Pillemer SR, Tak PP, Sankar V. B cell MALT lymphoma diagnosed by labial minor salivary gland biopsy in patients screened for SjšgrenÕs syndrome. Ann Rheum Dis. 2005 Mar;64(3):471Ð3.

20.Caporali R, Bonacci E, Epis O, Bobbio-Pallavicini F, Morbini P, Montecucco C. Safety and usefulness of minor salivary gland biopsy: retrospective analysis of 502 procedures performed at a single center. Arthritis Rheum. 2008 May 15;59(5):714Ð20.

21.Pijpe J, Kalk WW, van der Wal JE, Vissink A, Kluin PM, Roodenburg JL, et al. Parotid gland biopsy compared with labial biopsy in the diagnosis of patients with primary SjšgrenÕs syndrome. Rheumatology (Oxford). 2007 Feb;46(2):335Ð41.

22.Caporali R, Bonacci E, Epis O, Morbini P,

Montecucco C. Comment on: parotid gland biopsy compared with labial biopsy in the diagnosis of patients with primary SjšgrenÕs syndrome. Rheumatology (Oxford). 2007 Oct;46(10):1625Ð6.

23.Daniels TE, Aufdemorte TB, Greenspan JS. Histopathology of SjšgrenÕs syndrome. In: Talal N, Moutsopoulos HM, Kassan SS, editors. SjšgrenÕs syndrome Ð clinical and immunological aspects. Berlin: Springer; 1987, pp. 41Ð52.

24.Daniels TE. Labial salivary gland biopsy in SjšgrenÕs syndrome. Assessment as a diagnostic criterion in 362 suspected cases. Arthritis Rheum. 1984;27(2):147Ð56.

25.Daniels TE. Salivary histopathology in diagnosis of SjšgrenÕs syndrome. Scand J Rheumatol Suppl. 1986;61:36Ð43.

26.Richards A, Mutlu S, Scully C, Maddison P. Complications associated with labial salivary gland biopsy in the investigation of connective tissue disorders. Ann Rheum Dis. 1992 Aug;51(8):996Ð7.

27.Friedman JA, Miller EB, Huszar M. A simple technique for minor salivary gland biopsy appropriate for use by rheumatologists in an outpatient setting. Clin Rheumatol. 2002 Aug;21(4):349Ð50.

28.Biasi D, Mocella S, Caramaschi P, Carletto A, Baracchino F, Colletti V, et al. Utility and safety of parotid gland biopsy in SjšgrenÕs syndrome. Acta Otolaryngol. 1996 Nov;116(6):896Ð9.

29.Vitali C, Bombardieri S, Moutsopoulos HM, Balestrieri G, Bencivelli W, Bernstein RM, et al. Preliminary criteria for the classiÞcation of SjogrenÕs syndrome. Results of a prospective concerted action supported by the European Community. Arthritis Rheum. 1993 Mar;36(3):340Ð7.

30.Fox RI, Robinson CA, Curd JG, Kozin F, Howell FV. SjšgrenÕs syndrome. Proposed criteria for classiÞcation. Arthritis Rheum. 1986 May;29(5): 577Ð85.

31.Chisholm DM, Mason DK. Labial salivary gland biopsy in SjšgrenÕs disease. J Clin Pathol. 1968 Sep;21(5):656Ð60.

32.Chisholm DM, Waterhouse JP, Mason DK. Lymphocytic sialadenitis in the major and minor glands: a correlation in postmortem subjects. J Clin Pathol. 1970 Nov;23(8):690Ð4.

33.Greenspan JS, Daniels TE, Talal N, Sylvester RA. The histopathology of SjšgrenÕs syndrome in labial salivary gland biopsies. Oral Surg Oral Med Oral Pathol. 1974 Feb;37(2):217Ð29.

34.Daniels TE, Whitcher JP. Association of patterns of labial salivary gland inßammation with keratoconjunctivitis sicca. Analysis of 618 patients with suspected SjšgrenÕs syndrome. Arthritis Rheum. 1994 Jun;37(6):869Ð77.

35.Whaley K, Williamson J, Chisholm DM, Webb J, Mason DK, Buchanan WW. SjšgrenÕs syndrome. I. Sicca components. Q J Med. 1973 Apr;42(166): 279Ð304.

36.Takeda Y. Histopathological studies of the labial salivary glands in patients with SjogrenÕs syndrome. Part I: light microscopic study. Bull Tokyo Med Dent Univ. 1980/03/01 ed 1980:9Ð25.

37.Vitali C, Moutsopoulos HM, Bombardieri S. The European Community Study Group on diagnostic criteria for SjšgrenÕs syndrome. Sensitivity and speciÞcity of tests for ocular and oral involvement in SjšgrenÕs syndrome. Ann Rheum Dis. 1994 Oct;53(10):637Ð47.

38.Atkinson JC, Travis WD, Slocum L, Ebbs WL, Fox PC. Serum anti-SS-B/La and IgA rheumatoid factor are markers of salivary gland disease activity in primary SjšgrenÕs syndrome. Arthritis Rheum. 1992 Nov;35(11):1368Ð72.

39.Vivino FB, Gala I, Hermann GA. Change in Þnal diagnosis on second evaluation of labial minor salivary gland biopsies. J Rheumatol. 2002 May;29(5): 938Ð44.

40. Al-Hashimi I, Wright JM, Cooley CA, Nunn ME. Reproducibility of biopsy grade in SjšgrenÕs syndrome. J Oral Pathol Med. 2001 Aug;30(7): 408Ð12.

41.Morbini P, Manzo A, Caporali R, Epis O, Villa C, Tinelli C, et al. Multilevel examination of minor salivary gland biopsy for SjšgrenÕs syndrome signiÞcantly improves diagnostic performance of AECG classiÞcation criteria. Arthritis Res Ther. 2005;7(2):R343Ð8.

42.Scardina GA, Spano G, Carini F, Spicola M, Valenza V, Messina P, et al. Diagnostic evaluation of serial sections of labial salivary gland biopsies in SjšgrenÕs syndrome. Med Oral Pathol Oral Cir Bucal. 2007 Dec;12(8):E565Ð8.

43.Jonsson MV, Skarstein K. Follicular dendritic cells conÞrm lymphoid organization in the minor salivary

glands of primary SjšgrenÕs syndrome. J Oral Pathol Med. 2008 Oct;37(9):515Ð21.

44.Jonsson MV, Skarstein K, Jonsson R, Brun JG. Serological implications of germinal center-like structures in primary SjšgrenÕs syndrome. J Rheumatol. 2007 Oct;34(10):2044Ð9.

45.Salomonsson S, Jonsson MV, Skarstein K, Brokstad KA, Hjelmstršm P, Wahren-Herlenius M, et al. Cellular basis of ectopic germinal center formation and autoantibody production in the target organ of patients with SjšgrenÕs syndrome. Arthritis Rheum. 2003 Nov;48(11):3187Ð201.

46.Janeway CA, Travers P, Walport M, Schlomchik

M.Immunobiology: the immune system in health and disease. 6th ed. New York: Garland Science Publishing; 2005, p. 378.

47.Amft N, Curnow SJ, Scheel-Toellner D, Devadas A, Oates J, Crocker J, et al. Ectopic expression of the

Bcell-attracting chemokine BCA-1 (CXCL13) on endothelial cells and within lymphoid follicles contributes to the establishment of germinal center-like structures in SjšgrenÕs syndrome. Arthritis Rheum. 2001 Nov;44(11):2633Ð41.

48.Jonsson MV, Szodoray P, Jellestad S, Jonsson R, Skarstein K. Association between circulating levels of the novel TNF family members APRIL and BAFF and lymphoid organization in primary SjšgrenÕs syndrome. J Clin Immunol. 2005 May;25(3): 189Ð201.

49.Stott DI, Hiepe F, Hummel M, Steinhauser G, Berek

C.Antigen-driven clonal proliferation of B cells within the target tissue of an autoimmune disease. The salivary glands of patients with SjšgrenÕs syndrome. J Clin Invest. 1998 Sep 1;102(5):938Ð46.

50.Takemura S, Braun A, Crowson C, Kurtin PJ, CoÞeld RH, OÕFallon WM, et al. Lymphoid neogenesis in rheumatoid synovitis. J Immunol. 2001 Jul 15;167(2):1072Ð80.

51.Sims GP, Shiono H, Willcox N, Stott DI. Somatic hypermutation and selection of B cells in thymic germinal centers responding to acetylcholine receptor in myasthenia gravis. J Immunol. 2001 Aug 15;167(4):1935Ð44.

52.SeraÞni B, Rosicarelli B, Magliozzi R, Stigliano E, Aloisi F. Detection of ectopic B-cell follicles with germinal centers in the meninges of patients with secondary progressive multiple sclerosis. Brain Pathol. 2004 Apr;14(2):164Ð74.

53.Mazzucchelli L, Blaser A, Kappeler A, SchŠrli P, Laissue JA, Baggiolini M, et al. BCA-1 is highly expressed in Helicobacter pylori-induced mucosaassociated lymphoid tissue and gastric lymphoma. J Clin Invest. 1999 Nov;104(10):R49Ð54.

54.Grant AJ, Goddard S, Ahmed-Choudhury J,

Reynolds G, Jackson DG, Briskin M, et al. Hepatic expression of secondary lymphoid chemokine (CCL21) promotes the development of portal-associated lymphoid tissue in chronic inßammatory liver disease. Am J Pathol. 2002 Apr;160(4):1445Ð55.

55.Armengol MP, Juan M, Lucas-Martin A, FernandezFigueras MT, Jaraquemada D, Gallart T, et al. Thyroid autoimmune disease: demonstration of thyroid antigen-speciÞc B cells and recombinationactivating gene expression in chemokine-containing active intrathyroidal germinal centers. Am J Pathol. 2001 Sept;159(3):861Ð73.

56.Larsson •, Warfvinge G. The histopathology of oral mucosal lesions associated with amalgam or porcelain-fused-to-metal restorations. Oral Dis. 1995 Sep;1(3):152Ð8.

57.Larsson •, Warfvinge G. Immunohistochemistry of Ôtertiary lymphoid folliclesÕ in oral amalgamassociated lichenoid lesions. Oral Dis. 1998 Sep;4(3):187Ð93.

58.Theander E, Manthorpe R, Jacobsson LT. Mortality and causes of death in primary SjšgrenÕs syndrome: a prospective cohort study. Arthritis Rheum. 2004 Apr;50(4):1262Ð9.

59.Raderer M, Osterreicher C, Machold K, Formanek M, Fiebiger W, Penz M, et al. Impaired response of gastric MALT-lymphoma to Helicobacter pylori eradication in patients with autoimmune disease. Ann Oncol. 2001 Jul;12(7):937Ð9.

60.Streubel B, Huber D, Wohrer S, Chott A, Raderer

M.Frequency of chromosomal aberrations involving MALT1 in mucosa-associated lymphoid tissue lymphoma in patients with SjšgrenÕs syndrome. Clin Cancer Res. 2004 Jan 15;10(2):476Ð80.

61.Theander E, Henriksson G, Ljungberg O, Mandl T, Manthorpe R, Jacobsson LT. Lymphoma and other malignancies in primary SjšgrenÕs syndrome.

Acohort study on cancer incidence and lymphoma predictors. Ann Rheum Dis. 2005 Nov 10;65: 796Ð803.

62.Reksten TR, Jonsson MV, Szyszko EA, Brun JG, Jonsson R, Brokstad KA. Cytokine and autoantibody proÞling related to histopathological features in primary SjšgrenÕs syndrome. Rheumatology (Oxford). 2009;48(9):1102Ð6.

63.Szyszko EA, Brokstad KA, ¯ijordsbakken G, Jonsson MV, Jonsson R, Skarstein K. Salivary glands of primary SjšgrenÕs syndrome patients express factors vital for plasma cell survival. Arthritis Res Ther. 2011;13(1):R2.64.

64.Theander E, Vasaitis L, Baecklund E, Nordmark G, Warfvinge G, Liedholm R, et al. Lymphoid organisation in labial salivary gland biopsies is a possible predictor for the development of malignant lymphoma in primary SjšgrenÕs syndrome. Ann Rheum Dis. 2011;(70): In press.

65.Christodoulou MI, Kapsogeorgou EK, Moutsopoulos HM. Characteristics of the minor salivary gland inÞltrates in SjšgrenÕs syndrome. J Autoimmun. 2010;34(4):400Ð7.

66.Le Pottier L, Devauchelle V, Fautrel A, Daridon C, Saraux A, Youinou P, et al. Ectopic germinal centers are rare in SjšgrenÕs syndrome salivary glands and do not exclude autoreactive B cells. J Immunol. 2009;182(6):3540Ð7.

Salivary gland tissue in SjšgrenÕs syndrome is characterized by focal mononuclear cell inÞltration, loss of salivary gland acinar epithelial tissue, and degenerative changes such as Þbrosis. This makes functional imaging like scintigraphy and MRI obvious choices [1, 2]. In contrast to the histopathological evaluation where the minor or parotid salivary glands are examined, the gland of choice for functional evaluation is the major salivary glands, i.e., the parotid glands

J.T. Geitung ( )

Haraldsplass Deaconess University Hospital, Bergen, Norway

e-mail: jtgeit@online.no; jonn.terje.geitung@haraldsplass.no

and/or the submandibular glands. In cases where the labial salivary gland biopsy is insufÞcient or not possible to perform, there is a potential diagnostic role for sialographic and scintigraphic examinations [3].

Important to imaging techniques is also the typical pattern of parotid gland ducts, where the conventional X-ray sialography is still considered the gold standard for showing changes [4, 5]. It has, however, in part been replaced by MR sialography.

Imaging procedures have had rapid progress throughout recent years, both with improvements in existing techniques and development of new imaging techniques. In addition to sialometry [see Chapter 14, Oral and Dental Manifestations