Prevalence of clinical characteristics of patients with a (probable) Behçet*s syndrome in the Netherlands, a follow up cohort study.

Behçet*s syndrome (BS) is characterized by orogenital ulcera and uveitis and is
most common in countries along the Silk Road. It is an orphan disease in
Western countries. Presentation varies with gender and also with geographical
area. This implicates that classification criteria based on an endemic
population might not be adequate for Western patients. At this time incomplete
data on the presentation of patients with (suspected) BS in the Netherlands are
present. This complicates diagnosis and also prediction of likelihood of
developing BS. The exact pathogenesis remains unclear. Environmental and
infectious factors are thought to play a role in the development of the
disease. Furthermore, 10% of patients in Turkey have a positive family history,
suggesting a role for genetic factors. Also, BS has both histological and
clinical features of dysregulation of the innate and adaptive immune system.
Lastly, NETosis (neutrophils forming extracellular traps to immobilize and kill
invading microbes) may play a role in BS. By netting, Neutrophils externalize
autoantigens, making them more exposed to the adaptive and innate immune
system. The role of NETosis in BS has not been assessed yet.

Main objective is to collect longitudinal follow up data of all patients with
(suspected) Behçet*s syndrome. In order to study prevalance and incidence of
clinical disease manifestations.
Secondary objectives:
1. What is the prevalence of various disease manifestations (for example
uveitis and DVT) and damage accumulation (like visual loss and cataract) in
patients with BS in the Netherlands?
2. What is the level of disease activity in patients with Behçet*s syndrome as
well in those with suspected BS, when measured using the BD-CAF, BSAS and ARMD
BD-HAQ?
3. What is the quality of life in patients with (suspected) BS, does it
correlate with disease activity or damage accumulation?
4. What is the incidence of pathergy positivity? Is patient evaluation of
pathergy testing equally reliable, compared to a) real time assessment by a
dermatologist or b) assessment of photographs by a trained physician?
5. To study genetics in patients with BS (in relation to clinical
manifestations)
6. To create a prediction rule for patients with suspected BS.
7. To study immune regulation in patients with (suspected) BS, specifically
clonal T cell expansion and antigen presentation via MHC1.
8. To study the role of NETosis in patients with (suspected) BS.

observational, longitudinal.
biobanking

The burden of our first studyvisit (for entirely NEW patients) consists of the
collection of 2 tubes of blood for regular care purposes and 14 to a maximum of
15 additional tubes of blood for study purposes. Also, patients are asked to
complete 3 additional questionnaires, of which once a Quality of Life
questionnaire.
For those patients who come for visit 2 (were included in the former cross
sectional Behcet study allready), 14 extra tubes of blood will be drawn. And 2
extra questionnaires (not the QoL questionnaire).

Regarding follow up:
In patients who consent for the follow up study protocol (those who were
included in the cross sectional study earlier and the new patients as well),
all information of all follow up visits will be added to the database, with 2
additional questionnaires, the type of follow up will be either yearly or every
visit information will be put in the database. Every follow up visit 2 extra
questionaires will be done. Once a year 3 extra tubes of blood will be drawn
(all patients).

In case of a flare 14 extra tubes of blood and 2 questionnaires (this is once).

Benefit: more understanding of the disease, better care for individual patients
due to the dedicated nature and extensive typing of complaints. Specifically
for those with a probable BS the benefit will be creating a prediction model.