A diagnostic test for scabies: IgE specificity for a recombinant allergen of Sarcoptes scabiei.
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.
Menzies School of Health Research, Darwin, Northern Territory 0810, Australia.
Rama
R
Jayaraj
Belinda
B
Hales
Linda
L
Viberg
Susan
S
Pizzuto
Deborah
D
Holt
Jennifer M
JM
Rolland
Robyn E
RE
O'Hehir
Bart J
BJ
Currie
Shelley F
SF
Walton
D000485:Allergens / Q000235:genetics; D000818:Animals; D003429:Cross Reactions; D003955:Diagnostic Tests, Routine / Q000379:methods*; D006801:Humans; D007118:Immunoassay / Q000379:methods; D007073:Immunoglobulin E / Q000097:blood*; D010274:Parasitology / Q000379:methods*; D011994:Recombinant Proteins / Q000235:genetics; D012520:Sarcoptes scabiei / Q000737:chemistry* / Q000276:immunology; D012532:Scabies / Q000175:diagnosis*; D012680:Sensitivity and Specificity
D000485:Allergens; D011994:Recombinant Proteins; D007073:Immunoglobulin E