Anticardiolipin antibodies (aCL) have been reported to occur in a wide vari
ety of autoimmune and non-autoimmune disorders in adults.
Our objective was to investigate the prevalence and isotype distribution of
aCL and its relationship with the features of antiphospholipid syndrome (A
PS) in childhood rheumatic disorders.
Between November 1995 and May 1996, all patients who visited our paediatric
rheumatology clinic whose guardians signed a consent form participated in
the study. The study population included 106 patients (36 systemic lupus er
ythematosus (SLE), 28 juvenile rheumatoid arthritis (JRA), 11 fibromyalgia,
7 sarcoidosis, 5 dermatomyositis, 3 rheumatic fever (RF), 3 vasculitis, 2
scleroderma, and 11 miscellaneous). aCL measurements were performed by enzy
me linked immunoabsorbent assay (ELISA). All patients were carefully evalua
ted for symptoms and signs of APS.
Eighteen of the 106 patients (17%) were tested positive for one or more of
the three aCL isotypes. In SLE, aCL were found positive in 13 of 36 (37%);
in JRA 2 of 28 (7%); in sarcoidosis 2 of 7; and in RF 1 of 3. aCL of IgG is
otype were found positive in 16 patients (1 1 SLE, 2 sarcoidosis, 2 JRA, an
d 1 RF). This isotype was usually detected at low titers (16-24 GPL). aCL o
f IgM isotype were found positive in five patients (2 sarcoidosis, 2 SLE, 1
JRA), and aCL of IgA isotype were found positive in only three patients (2
SLE, I sarcoidosis). Clinical features of APS were rarely seen in our SLE
population and were not associated with the presence of aCL. None of the pa
tients in the other groups exhibited any clinical manifestations of APS.
In conclusion, aCL were found in 37% of our childhood SLE patients as compa
red with only 7% in JRA. These were mostly aCL of IgG isotype of low titers
and therefore were not associated with the main features of APS. Prospecti
ve studies with a larger sample size may be needed to ascertain the exact p
revalence and clinical significance of aCL in childhood-onset SLE.