Anti-platelet factor 4/heparin antibody is associated with progression of peripheral arterial disease in hemodialysis patients.

Background: Heparin therapy may induce anti-platelet factor 4/heparin antibody (PF4-H Ab). Hemodialysis patients receive scheduled heparin and are at a risk of developing PF4-H Ab. Hemodialysis patients are also at a high risk of peripheral arterial disease (PAD). This study examines whether chronic PF4-H Ab exposure contributes to the progression of PAD measured by ankle brachial index (ABI) in hemodialysis patients.

Methods: A total of 71 hemodialysis patients were enrolled, and the association between clinical, biochemical parameters and ABI after 3 years was studied. PF4-H Ab was evaluated by ELISA, and patients with titer ≥ 0.4 were taken as having PF4-H Ab.

Results: Mean ABI was 1.04 ± 0.18 at baseline and 1.01 ± 0.17 after 3 years. Mean ΔABI (change in ABI after 3 years) was -0.04 ± 0.13. PF4-H Ab was positive in 26 patients. PF4-H Ab was not related to hemodialysis duration, DM history, smoking and age. Platelet count showed no correlation with PF4-H Ab. However, there was significance in ΔABI between PF4-H Ab-positive and PF4-H Ab-negative patients (p = 0.002). ΔABI was negatively correlated with PF4-H Ab and 3-year averaged serum Ca × P only (β = -0.378, p = 0.001; β = -0.263, p = 0.018, respectively). However, in PF4-H Ab-positive patients, the extent of ΔABI did not correlate with PF4-H Ab titers (r = -0.021, p = 0.921).

Conclusions: PF4-H Ab positivity, along with high levels of serum Ca × P, played a potential role in the progression of PAD over time.