Development of a dendrimer PAMAM­based gold biochip for rapid and sensitive detection of endogenous IFN­Î³ and anti­IFN­Î³ IgG in patients with hemophagocytic lymphohistiocytosis.

ABSTRACT

Hemophagocytic lymphohistiocytosis (HLH) is a rare but severe disease characterized by immune hyperactivation and cytokine storm. Given the high mortality rate of HLH, there is a need for more effective diagnostic tools and treatments. The present study developed a dendrimer­based protein biochip for rapid, sensitive and simultaneous detection of serum interferon (IFN)­Î³ and endogenous anti­IFN­Î³ antibody (Ab) in patients with HLH. A gold biochip was modified with 1, 4­phenylene diisothiocyanate (PDITC), polyamidoamine (PAMAM) or PDITC­activated PAMAM. The optimal immobilization concentration for Ab capture and the reaction concentration for detecting Ab on the PDITC­activated PAMAM­modified biochip were 6.25 and 3.12 µg/ml, respectively; the limit of detection of IFN­Î³ protein was 50 pg/ml. The efficiency of the protein­probed biochip in detecting IFN­Î³ and anti­IFN­Î³ Ab in serum samples from 77 patients with HLH was evaluated; the positive rates for IFN­Î³ and anti­IFN­Î³ IgG Ab were 63.6% (49/77) and 61.0% (47/77), respectively. The present results demonstrated that the PDITC­activated PAMAM­modified biochip might be a sensitive tool for the specific detection of IFN­Î³ and anti­IFN­Î³ Ab in serum, and might have clinical applicability for the diagnosis of HLH.