Simultaneous detection of platelet-specific antibodies based on a photonic crystal-encoded suspension array

• Photonic crystal has distinct reflection spectra and is applied as bio-molecular supports.
• Photonic crystal encoded suspension array was built up to detect platelet specific antibodies simultaneously.
• PCSA showed greater or comparable sensitivity than MAIPA in testing different platelet antibodies.
• The entire testing process is completed within 3.5 h.
• Photonic crystal encoded suspension array for detect anti-platelet antibodies has potential clinical application.

BackgroundThe appearance of antibodies to platelets in the blood is an important cause of immune thrombocytopenia (ITP), and platelet glycoprotein (GP)-specific antibody detection may be helpful to diagnose this condition.MethodsPhotonic crystal microspheres with different distinct reflection spectra were coated with anti-GPIIb, -GPIIIa, -GPIb and -GPIX monoclonal antibodies (MoAbs) to create a photonic crystal-encoded suspension array (PCSA). Fluorescein isothiocyanate-labelled goat anti-human IgG was added to detect human IgG simultaneously. The detection results were analysed by fluorescence microscopy. Parallel MoAb immobilization of platelet antigen (MAIPA) was used as a reference test. Both methods were used to analyse 63 clinical samples including serum from 32 ITP patients and 31 healthy humans.ResultsThe PCSA showed greater sensitivity than MAIPA in detecting anti-GPIIb (75.0% vs 31.1%) and GPIIIa (84.4% vs 40.6%) antibodies and similar sensitivity as MAIPA in detecting anti-GPIb (37.5% vs 34.4%) and GPIX (50.0% vs 40.8%) antibodies. The MAIPA and PCSA tests had similar specificity. The PCSA detected higher dilutions of serum containing anti-GPIIIa antibody or anti-GPIIb antibody than did MAIPA. The entire testing process was controlled within 3.5 h.ConclusionsThe PCSA assay described has comparable or better sensitivity and specificity compared to the MAIPA and is more rapid.