VPB0737 - Prevalence and Impact of Antiphospholipid Antibodies on Thrombotic Events in Ambulatory Cancer Patients

Monday, July 11, 2022

6:30 PM – 7:30 PM

Location: Exhibition

Presentation Format: Virtual

Presenting Author(s)

Chalermkiat Kansuttiviwat, MD

Physician (Internal Medicine, Residency)
Faculty of Medicine, Chiang Mai University
Thailand, Chiang Mai, Thailand

Co-Author(s)

PN

Piangrawee Niprapan

Research nurse
chaing mai University
chiang mai, Chiang Mai, Thailand
LN

Lalita Norasetthada

Hematologist
Division of Hematology, Department of Internal Medicine, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
Sri Phum, Muang, Chiang Mai, Thailand
ER

Ekarat Rattarittamrong

associate professor
chaing mai University
chiang mai, Chiang Mai, Thailand
AT

Adisak Tantiworawit

associate professor
chaing mai University
chiang mai, Chiang Mai, Thailand
PP

Pokpong Piriyakhuntorn

Instructor
chaing mai University
chiang mai, Chiang Mai, Thailand
SH

Sasinee Hantrakool

Hematologist
Division of Hematology, Department of Internal Medicine, Chiang Mai University
Sri Phum, Muang, Chiang Mai, Thailand
Nonthakorn Hantrakun, MD

Instructor
chaing mai University
chiang mai, Chiang Mai, Thailand
TP

Teerachat Punnachet

Instructor
chaing mai University
chiang mai, Chiang Mai, Thailand
CC

Chatree Chai-Adisaksopha

Hematologist
Division of Hematology, Department of Internal Medicine, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
Sri Phum, Muang, Chiang Mai, Thailand

Background: Despite the conflicting data, the positivity of antiphospholipid antibodies (APLA) in cancer patients may be associated with an increased risk of thrombosis.

Aims: To identify the prevalence of APLA and impact of APLA on arterial and venous thrombosis in ambulatory cancer patients

Methods: This was a prospective cohort study. We enrolled newly diagnosed ambulatory cancer patients receiving chemotherapy. Controls were enrolled from age- and sex-matched non-cancer, non-autoimmune disease population. Participants were evaluated for APLA (lupus anticoagulant (LA), anti-cardiolipin (aCL) and anti-β2 glycoprotein 1 (anti-β2-GPI). Primary outcome was the prevalence of APLA positivity. Secondary outcomes were the prevalence of arterial and venous thrombosis and all-cause mortality at 6-month follow-up duration.

Results: There were 137 cases and 137 controls with mean age of 56.0±12.3 and 55.5±12.1 years, respectively. Cancer patients were more likely to have APLA positivity compared to controls, with risk difference of 2.9% (95% CI 0.1 to 5.7) for dual LA positivity, 5.8% (95% CI 0.2 to 9.7) for aCL IgM or IgG and 6.6% (-0.7 to 13.1) for anti-β2-GPI IgM or IgG (Table 1). Composites of venous and arterial thrombosis occurred in 10 (7.3%) in cancer patients and 2 (4.5%) in controls. Death occurred in 19 (13.9%) in cancer patients and 0% in controls. In cancer patients who had any APLA positivity were associated with higher risk of composites of venous and arterial thrombosis compared to those without (RR 3.6, 95% CI 1.0-12.4). Cancer patients with LA positivity were associated with higher risk of arterial or venous thrombosis (RR 5.3 95%CI 1.3-21.0), whereas patients with anti-β2-GPI positivity were associated with higher risk of venous thrombosis (RR 4.7, 95%CI 1.1-19.2), Table 2.

Conclusion(s): APLA was more prevalent in patients with active cancer than non-cancer patients. Positive APLA in cancer patients was associated with arterial or venous thrombosis.