REgistry of Pediatric Sjögren syndrome in Umcg- LongiTudinal (REPSULT)

Sjögren syndrome (SS) is a lifelong, systemic autoimmune disease that has major
impact on daily activities and quality of life. In adult SS the salivary and
lacrimal glands are most commonly affected, resulting in xerostomia (dry mouth)
and keratoconjunctivitis sicca (dry eyes). Pediatric-onset Sjögren syndrome
(pedSS) more often presents with other symptoms such as recurrent parotitis and
renal and neurological impairment. The underlying pathophysiological mechanism
in pedSS may be different from adult SS, with a more prominent role for
genetic diseases. The consequences of pedSS on daily life has not been studied.
For this reasons there is a urgent need to evaluate the value of the current
classification criteria in pedSS and further research in the pathophysiological
mechanisms and genetic background.

Our hypothesis is that pedSS has a different presentation and pathophysiology
than adult SS, with more genetic involvement. To test this hypothesis, we
define the following specific aims: define disease presentation of children
with SS-like complaints, analyze and describe the clinical course and HRQoL of
pedSS, evaluate current adult classification criteria in pedSS patients, assess
essential biomarkers (of adult SS) in children with SS, analyze the genetic
constitution of pedSS and identify predictors of MALT lymphoma in pedSS.

The design will be a longitudinal observational prospective cohort study. All
consecutive patients with confirmed or probable SS before the age of 17 years,
who visit the (outpatient) clinic of the department of Pediatric Rheumatology
in the UMCG are considered for this study. Inclusion will take place during 10
years and all patients will be followed up for 10 years. Visits according to a
fixed protocol will be performed at baseline and every year thereafter, with
more extensive evaluation after 1, 2, 5 and 10 years of follow up (Figure 1).
If indicated, additional visits may be scheduled as part of standard care, i.e.
because of high disease activity or treatment with systemic immunosuppressant
drugs. This additional visits can also take place in the referring hospital in
a shared care construction. For patients with probable pedSS, the clinical
suspicion of pedSS might be lowered during follow-up, making yearly visits
unnecessary. From the moment yearly visits will be stopped and these patients
will be followed up only in year 1, 2, 5 and 10. When patients reach the age of
18 the clinical care will be transferred to the adult rheumatologist, but they
will continue to participate in the REPSULT cohort.

Participants will visit the outpatient clinic in the context of clinical care,
and will not bring additional visits to the hospital. Extra measurements (which
do not concern the regular clinical follow-up of pedSS patients) are
questionnaires on xerostomia, health related quality of life and school and
collection of extra blood (during routine venepuncture), saliva and tears and a
yearly ultrasound of the parotic glands (non-invasive procedures). Diagnostic
procedures or treatment will not be postponed. Overall, the burden for the
participants is low and the risk of participation is negligible as no extra
invasive procedures will be done. Patients will not experience any direct
benefits from participation in this cohort. However, the results of this cohort
might improve the quality of care for patients with (pediatric) SS in the
future. Therefore, we assume that the advantages of participation in this
cohort outweigh the burden of participation.