What is new in the pathogenesis and diagnosis of Sjögren's syndrome

Sandhya Pulukool, MDAssociate ProfessorDepartment of RheumatologyChristian Medical College and Hospital, Vellore

DIAGNOSIS

ACR/EULAR classification criteria for primary Sjögren's syndrome 2016

5 criteria itemsWeighted scoreSCORE of ≥4

Shiboski CH et al Ann Rheum Dis. 2016

Item Weight

Focus score of ≥1 foci/4 mm2 3

Anti-SSA/Ro positive 3

Ocular Staining Score ≥5 (or van Bijsterveld score ≥4) in at least 1 eye 1

Schirmer’s test ≤5 mm/5 minutes in at least 1 eye 1

Unstimulated whole saliva flow rate ≤0.1 ml/minute 1

Validated in a separate cohortSensitivity-96% (92–98%) and specificity-95%(92–97%)against clinician-expert–classificationAgreement (k) with AECG criteria (0.91) ACR criteria (0.82)

International Sjogren’s Syndrome Criteria Working Group

DIAGNOSIS

ACR/EULAR classification criteria for primary Sjögren's syndrome 2016

Inclusion criteria

Any patient with at least 1 symptom of ocular or oral dryness defined as a positive response to at least 1 of the following

1) Daily , persistent, troublesome dry eyes for >3 months?2) Recurrent sensation of sand or gravel in the eyes?3) Use tear substitutes > 3 times a day? 4) Daily feeling of dry mouth for >3 months5) Drink liquids to aid in swallowing dry food?

OR

Suspicion of SS from the ESSDAI questionnaire (at least 1 domain with a positive item)

Exclusion criteriaHepatitis C infection (confirmation by PCR) preexisting lymphoma is allowable

Relevance of Minor Salivary Gland Biopsy

• FS ≥3 positive predictive value of 16% for lymphoma

• FS of <3 associated with a negative predictive value of 98%

Risselada AP Ann Rheum Dis (2014) The Netherlands

• GC-like structures in upto 25% of pSS• GC formation is associated with higher FS, RF, anti-SSA and SSB

positivity Risselada AP Semin Arthritis Rheum. (2013) The Netherlands

FS-focus score GC-germinal center

DIAGNOSIS

DIAGNOSIS

Serology

Antibodies against carbamylated proteins

20% pSSAssociated with IgG, IgM, RF, β2-microglobulin9.2-fold higher odds of GC

Anti-TRIM38

10% pSSAssociated with anti-Ro60,anti-Ro52, anti-La, RF, and IgFocus scores of ≥3.0

Brith Bergum, Ann Rheum Dis. (2016) Norway

Wolska N, Arthritis Rheumatol (2016) US

Anti-Muscarinic3 Receptor

Meta –analysis-11 studiesPooled diagnostic OR 13.00 ( 6.00-26.00)Sensitivity-0.43 (95% CI, 0.28-0.58)Specificity 0.95 (95%CI, 0.91-0.97)

Deng C PLoS One (2015)

Salivary anti-M3RSensitivity- 0.44 Specificity -0.8855.81% SSMore in younger patientsHigh Ig Jayakanthan K Clin Rheumatol (2016) India

DIAGNOSIS

Ultrasound and Sjögren's syndrome

• Meta –analysis• 37 studies and 33 ultrasonographic scoring systems• High risk of bias • Significant heterogeneity

• Sensitivity 0.69 (95%CI: 0.67-0.71)• Specificity 0.92 (95%CI: 0.91-0.93)• Diagnostic  odds ratio 33.89 (95%CI: 20.75-55.35)• Low quality of studies-no judgement possible

K Delli Oral Dis (2015) 

PATHOGENESIS

Sjögren's syndrome - Lupus of mucosa

Nocturne, G. & Mariette, X. Nat. Rev. Rheumatol (2013)

Virus/ Endogenous nucleic acid

TLR /Cytosolic RNA/DNA sensors

pDCTypeI IFNα

BAFF

B cells

Th1,NK cellType II IFNγ

TFH

IL21

Th17IL17

Genetics &Epigenetics

TLR-Toll like receptorpDC- plasmacytoid dendritic cellsBAFF :B-cell activating factor

PATHOGENESIS

Long Interspersed Nuclear Element 1 (L1) Retroelements triggers  type I IFN pathway

Levels of L1 messenger RNA transcripts were increased in MSG tissue of SS

Transcript expression correlated with the expression of type I IFN

Mavragani CP Arthritis Rheumatol (2016) Greece, US 

RNATLR7/8 9 cGAS

RIG-1

IFN α

DNA

ERV/LINE-1

PATHOGENESIS

Epstein-Barr virus infection causes disease-specific autoreactive B cell activation in ectopic lymphoid structures of SS

GC Bcell

TFH cell

EBV reactivation in perifollicular plasma cells that produce anti-Ro52 antibodies

anti-Ro 52/anti-La 48 anti-EBV antibodies but not ACPAs

Croia C Arthritis Rheumatol. (2014) UK

Active EBV infection associated with ELS in salivary glands

SCID mice

Serum

PATHOGENESIS

Interferon  (IFN) expression correlates with key phenotypic features

Hall JC Arthritis Rheumatol (2015) US

• Three distinct patterns of IFN in salivary gland• type I-predominant, type II-predominant, and type I/II mixed

• High IFN activity associated with• abnormal sialometry, • leukopenia• hyperglobulinemia • high-titer ANA • anti-SSA, and • high focus score

• Focus score highest in type II-predominant IFN(IFNγ)

•High IFNγ:IFNα ratio predictive of SS-lymphoma cut-off values > 22.3 specificity of 87.5% and sensitivity of 88.9%

Nezos A J Autoimmun (2015) Greece

PATHOGENESIS

Single-cell analysis of glandular T cell receptors in SS

• TCR repertoire in CD4+ memory T cells from SG and PB of 10 pSS by PCR

• Degree of clonal expansion increased in SG versus PB

• Expanded clones from SG had sequence similarity of CDR3 both within and among SS patients

• Antigenic selection of T cells and shared antigen recognition

• Extent of SG clonal expansion correlated with reduced saliva production and increased SG fibrosis

JCI Insight. 2016 US 

APC

TH

Activated TH

T cell clones with identical TCR

VariableRegion

ConstantRegion

HypervariableRegion CDR3

PATHOGENESIS

Th17 cell play a critical role in the development of Sjogren’s syndrome

Lin X Ann Rheum Dis. (2015) Hong Kong

No SG dysfunction

IL-17 KO C57BL/6 Wild C57BL/6

Adoptive transfer ofTh17 cells

Serum autoantibody production Tissue destructionIncreased Th17 cells

Cervical LN andLymphocytic foci in inflammed SG

Salivary gland

Antigen immunisation

PATHOGENESIS

LighTs off ! New Villians in SS Unaffected Haskett, J Immunol. (2016), UK

Lymphotoxin/LIGHT Signaling Axis- lymphoid organisation and immune cell recruitment

Lymphotoxin β receptor

Baminercept (Blocks the Lymphotoxin β receptor ) Negative results of Baminercept trial??

PD programmed death 1ICOS Inducible T-cell COStimulator

Two PD1 hi ICOS hi effector subsets PD1 hi Il21 Th1 phenotypePD1 hi Il10 eTreg phenotype

PD1- naive conventional T cells

NOD mice model

PATHOGENESIS

RBMS3 a novel susceptibility gene associated with female pSS

Hum Genet. 2016 Taiwan

•GWAS in Han Chinese population•RBMS3(P = 4.89 × 10-5)

•Modulating acinar apoptosis and TGF-β

signaling in target exocrine system

Gene associated to germinal centre formationcase-only candidate gene study SNPs in CCL11 (eotaxin)

Reksten TR, Ann Rheum Dis. 2014, Norway

Germline variation of TNFAIP3 in SS-associated lymphomaOR- 2.7 UK 3.12(French) Nocturne J Ann Rheum Dis. 2016 UK ,France

PATHOGENESIS

Epigenetics• Hypomethylation of interferon (IFN)-regulated genes in all three tissues --blood, B cells, T cells, MSG

•Hypomethylation of IFN-regulated genes• Seropositive patients• Correlated with increased gene expression

• Genes--Inflammatory genes and immune-cell markers and genes of GWAS

• Methylation status of the top five differentially methylated genes inversely correlated with focus score and with ocular staining score

Imgenberg-Kreuz J Ann Rheum Dis. 2016 Sweden

Cole M B et al Arthritis Rheumatol. (2016) US

Miceli-Richard C et al Ann Rheum Dis.(2016)  France

• Less diversity in pSS• Microbial dysbiosis independent of

hyposalivation Siddiqui H ,J Oral Microbiol 2016 ,Norway

Ann Rheum Dis (2015) Abstract,India

Szymula A ,Clin Immunol. (2014) US• A peptide from the von Willebrand factor type

A domain protein (vWFA) from the oral microbe Capnocytphaga ochracea 

• Activates Ro60 reactive T cells and induce autoantibody responses against Ro60

• Firmicutes ,Streptococcus , Capnocytophaga , and Veillonella enriched

• Pseudomonas, Synergistetes and Spirochaetes depleted

Salivary microbiome –cause or effect

Desiccating stressScopolaminelow humidity

Antibiotics

C57BL/6 mice

environmental mouse model of dry eye

Gut dysbiosis

Increased IFNγ, dec IL-13 in conjunctiva

Worsens ocular inflammation

SS ocular and systemic disease was inversely correlated with microbial diversity

SS mice with gut dysbiosis DON’T CRY

de Paiva Sci Rep 2016,USA

• Decrease in Clostridium • Increase in Enterobacter,

Escherichia/ Shigella, and Pseudomonas

PATHOGENESIS

Sjögren's syndrome - Lupus of mucosa

EBV-Virus/ Endogenous nucleic acid-LINE 1

TLR /Cytosolic RNA/DNA sensors

pDCTypeI IFNα

BAFF

B cells

Th1,NK cellType II IFNγ

TFH

IL21

Th17IL17

Genetics-TNFAIP3, RBMS3, CCL11 Epigenetics-Hypomethylation-IFN Microbiome-salivary, gut

T

T

T

T

T

T

T

DC

BB

New T cell subsetsCD4+PD HI

Increased clonality of SG T cell –antigen driven

High IFNγ:IFNα

CCL11

Lymphoma

Regarding new ACR/EULAR criteria for Sjogrens syndrome, which is false

1)OSS≥32)5 Criteria items3)Weighted score4)Score ≥ 4

Thanks