Prevalence of sicca symptoms in a South Australian cohort with systemic sclerosis.
BACKGROUND
The presence of sicca symptoms is a frequent finding in patients with systemic sclerosis (SSc). The aim of this study was to examine the prevalence of sicca symptoms in a South Australian cohort of SSc patients and correlate this to a number of parameters, including autoantibody status, use of anticholinergic medication, age and the presence of functional anti-muscarinic-3 receptor (M3R)-blocking antibodies.


METHODS
A screening questionnaire was sent out to all patients on the South Australian Scleroderma Register from the years 1998-2006 to determine the prevalence of sicca symptoms. A subset of patients on the register had ocular sicca symptoms tested by use of Schirmer's strips to validate the accuracy of the questionnaire. Eight patients were tested for anti-M3R-blocking antibodies using a functional physiological assay.


RESULTS
One hundred and ninety-three SSc patients took part in this study. Sicca symptoms were present in 59% of patients with the limited form of SSc, compared with 49% of patients with the diffuse form and 40% of patients with the overlap syndrome. The use of anticholinergic medication or thyroxine was associated with higher sicca scores in SSc patients. SS-A and SS-B autoantibodies (seen in Sjögren's syndrome) were detected in eight patients in this study. The detection of anti-M3R-blocking antibodies correlated well to presence of sicca.


CONCLUSIONS
This study confirmed that sicca symptoms are found in a high proportion of patients with SSc, especially those with the limited variant. Further testing of larger numbers of SSc patients with sicca for anti-M3R-blocking antibodies will be needed before more definitive conclusions can be drawn. Physicians should be made aware that sicca symptoms are a frequent cause of morbidity for SSc patients*.
Swaminathan
S
S
Department of Immunology, Allergy and Arthritis, Flinders Medical Centre, Adelaide, South Australia, Australia.
Goldblatt
F
F
Dugar
M
M
Gordon
T P
TP
Roberts-Thomson
P J
PJ
D000328:Adult; D000368:Aged; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012042:Registries; D012595:Scleroderma, Systemic / Q000150:complications* / Q000175:diagnosis / Q000453:epidemiology*; D012859:Sjogren's Syndrome / Q000150:complications* / Q000175:diagnosis / Q000453:epidemiology*; D013021:South Australia / Q000453:epidemiology; D011795:Surveys and Questionnaires