title: Anti-platelet factor 4/heparin antibody is associated with progression of peripheral arterial disease in hemodialysis patients.
abstract: 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.
authors.affiliation: Division of Cardiology, Tainan Sinlau Hospital, Tainan, Taiwan, Republic of China.
authors.forename: Yen-Hsun
authors.initials: YH
authors.lastname: Chen
authors.forename: Kao-Chang
authors.initials: KC
authors.lastname: Lin
authors.forename: Yueh-Feng
authors.initials: YF
authors.lastname: Tsai
authors.forename: Lai-King
authors.initials: LK
authors.lastname: Yu
authors.forename: Li-Hsueh
authors.initials: LH
authors.lastname: Huang
authors.forename: Chien-An
authors.initials: CA
authors.lastname: Chen
mesh_terms: D055109:Ankle Brachial Index; D000906:Antibodies / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D001916:Brachial Artery / Q000000981:diagnostic imaging; D018450:Disease Progression; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007676:Kidney Failure, Chronic / Q000097:blood / Q000276:immunology / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D058729:Peripheral Arterial Disease / Q000097:blood / Q000209:etiology* / Q000276:immunology; D010978:Platelet Factor 4 / Q000276:immunology*; D006435:Renal Dialysis / Q000009:adverse effects*; D012189:Retrospective Studies; D016909:Tibial Arteries / Q000000981:diagnostic imaging; D014463:Ultrasonography
chemical_list: D000906:Antibodies; D015415:Biomarkers; D010978:Platelet Factor 4