Objective:
To analyze the
association between
thrombocytopenia and clinical manifestations in
patients with
antiphospholipid syndrome (APS), and the significance of adding
thrombocytopenia to the
classification criteria of APS.
Methods:
One hundred and sixty one APS
patients admitted to
Peking University People's
Hospital from January 2003 to August 2017 were retrospectively analyzed. Clinical and
laboratory data were compared between
patients with and without
thrombocytopenia.
Chi-square test, Fisher's exact test and t test were used for
statistical analysis.
Results:
Among 161 APS
patients, 48
patients (29.8%) were primary APS and 113
patients (70.2%) were
secondary APS. Ninety-one
patients (56.5%) experienced
thrombocytopenia, while 62
patients (38.5%) had
thrombocytopenia as the initial symptom. Among primary APS
patients, compared with
patients without
thrombocytopenia, the
prevalence of
thrombosis was significantly lower in
patients with
thrombocytopenia (40.0% vs 69.6%, χ2=4.218, P=0.040), especially
venous thrombosis (20.0% vs 47.8%, χ2=4.174, P=0.041). Among
secondary APS
patients, compared with
patients without thrombocyt-openia, the
prevalence of
thrombosis, arterial
thrombosis (21.2% vs 42.6%, χ2=5.944, P=0.015) and
venous thrombosis (22.7% vs 51.1%, χ2=9.753, P=0.002) was significantly lower in
patients with
thrombocytopenia (43.9% vs 80.9%, χ2=15.496, P<0.01). As for
laboratory findings, primary APS
patients with
thrombocytopenia showed a higher proportion of positive aCL findings (80.0% vs 52.2%, χ2=4.174, P=0.041), while
secondary APS
patients with
thrombocytopenia experienced more
leukopenia (25.8% vs 10.6%, χ2=4.002, P=0.045), lower
complement C3 levels (78.7% vs 44.4%, χ2=13.205, P<0.01) and
complement C4 levels (74.6% vs 46.7%, χ2=8.485, P=0.004). The proportion of
patients fulfilling 1988, 1989, 1999 and 2006 APS
classification criteria in our cohort was 88.2%, 87.0%, 64.0% and 70.8%, respectively. Inclusion of
thrombocytopenia into 2006 criteria improved the proportion to 96.3%.
Conclusion:
The
prevalence of
thrombosis in APS
patients with
thrombocytopenia is significantly low.
Thrombocytopenia is an important clinical manifestation of APS which can improve the diagnostic accuracy of APS.