Antiphospholipid Antibody Profiles Affect Patient Response to ITP Treatment

Different antiphospholipid antibody (APA) profiles in patients with immune thrombocytopenia (ITP) may affect individual response to ITP-specific treatments, according to a study published in Hematology (2019;24[1]:134-138).

“The relevance of detecting antibodies against anticardiolipin, β2-glycoprotein I (β2gpI) or lupus anticoagulant (LA), collectively called antiphospholipid autoantibodies (APA), in subjects with…ITP…is still a debated issue,” explained investigator Fabrizio Vianello, MD, Hematology and Clinical Immunology Unit, Department of Medicine, Padua University School of Medicine, Italy, and colleagues.

“In particular, whether APA profile may affect the clinical course of ITP is unknown,” they added.

Because of this, Dr Vianello and colleagues conducted a study to examine the relevance of different APA profiles in patients with ITP, and the affect these profiles have on clinical outcomes and responses to treatment.

A total of 159 patients fulfilled the ITP criteria for the trial, 37 (23.2%) of whom had a platelet count ≤50 × 109/L and tested positive for APA at ITP onset. Of these 37 patients, 23 (62.1%) received at least 1 previous line of ITP therapy.

Dr Vianello and colleagues reported that 14 patients with triple-positivity for APA had a significantly lower median platelet count compared with those who did not show triple-positivity for APA (P = .006). Of these 14 patients, 85.7% required treatment for low platelet count versus 47.8% of patients without triple-positive APA (P = .0094).

In addition, patients with APA who received immunosuppressors had a higher rate of thrombosis than those not given immunosuppressors (P = .024).

Dr Vianello and colleagues noted that the complete and spontaneous remission rates were significantly higher in ITP patients with triple-positive APA than in those without triple-positive APA (P = .021 and P = .005, respectively).

“In conclusion, different antiphospholipid antibody profile in ITP patients may affect the outcome and particularly indication and response to ITP-specific treatment,” Dr Vianello and colleagues concluded.—Janelle Bradley