Detection of antiplatelet antibodies in patients with idiopathic thrombocytopenic purpura (ITP) by immunofluorescence

An immunofluorescence test (IFT) using platelet suspensions was used to detect the presence of serum anti-platelet antibodies (APA) in the sera of Malaysian patients with idiopathic thrombocytopenic purpura. Of the 28 patients tested, 19 (or 68%) had detectable APA with percentage platelet fluorescence ranging from 34% - 80% (mean 51% +/- 10). Normal sera gave fluorescence values of 6 - 15% (mean 9% +/- 5). Sera from patients with SLE, thyrotoxicosis and dengue haemorrhagic fever gave mean values of 29%, 8% and 9% respectively. Additionally, no apparent correlation was observed between percentage platelet fluorescence and the severity of thrombocytopenia. The importance and significance of these findings are discussed.