Authors:
Jayaraj, R.; Hales, B.; Viberg, L.; Pizzuto, S.; Holt, D.; Rolland, J. M.; O'Hehir, R. E.; Currie, B. J.; Walton, S. F.
Authors notes:
Diagnostic Microbiology and Infectious Disease. 2011;71(4):403-7
Keywords:
Allergen, IgE, Immunodiagnostic, Sarcoptes scabiei, Scabies, lanthanide, recombinant allergen, recombinant antigen, antibody specificity, antigen binding, controlled study, cross reaction.
Abstract
Scabies infestations are difficult to diagnose clinically and current serologic tests have less than 50% accuracy. To develop more reliable diagnosis of scabies, specific IgE antibodies to a major scabies antigen recombinant Sar s 14.3 (rSar s 14.3) were measured in 140 plasma samples from scabies-infested and control subject groups using dissociation-enhanced lanthanide fluorescent immunoassays (DELFIA).
Levels of rSar s 14.3-specific IgE were quantified, and cross-reactivity with its house dust mite homologue, Der p 14, was assessed. The rSar s 14.3 DELFIA showed excellent diagnostic capability, with 100% sensitivity and 93.75% specificity for distinguishing subjects with current scabies infestation from control, uninfested subjects. Recombinant Der p 14 preparation was ineffective at inhibiting IgE binding to rSar s 14.3.
This study shows that quantification of levels of IgE antibody to rSar s 14.3 is a highly sensitive method for diagnosis of scabies infestation in clinical practice.