T Gordon1, C Mavrangelos, J McCluskey. 1. Department of Clinical Immunology, Flinders Medical Centre, Bedford Park, South Australia.
Abstract
OBJECTIVE: To determine whether anti-La/SS-B-positive sera that are precipitin negative show a distinct B cell epitope pattern. METHODS: Serum reactivity was tested with recombinant La/SS-B fusion proteins. RESULTS: Among the 18 precipitin-negative anti-La/SS-B-positive sera, reactivity was confined to the full-length recombinant protein (La33.3) in 8 (44%); 5 of 18 (28%) reacted only with La33.3 and with the first 107 N-terminal amino acids (LaA), and 4 (22%) reacted with La33.3, LaA, and the middle region of the La molecule (LaC; amino acids 111-242). One serum reacted with La33.3 and LaC. None of the 18 precipitin-negative sera was positive on a carboxy-terminal fragment (LaL2/3; amino acids 346-408). In contrast, all 26 precipitin-positive anti-La/SS-B-positive sera reacted with La33.3, LaA, and LaC, and 92% reacted with LaL2/3. Rheumatoid factor and serum IgG levels were significantly lower in the precipitin-negative group, providing further evidence of a distinct serologic subset. CONCLUSION: The restricted epitope recognition by these sera may explain the lack of precipitin formation and may represent an early autoantibody response to La/SS-B.
OBJECTIVE: To determine whether anti-La/SS-B-positive sera that are precipitin negative show a distinct B cell epitope pattern. METHODS: Serum reactivity was tested with recombinant La/SS-B fusion proteins. RESULTS: Among the 18 precipitin-negative anti-La/SS-B-positive sera, reactivity was confined to the full-length recombinant protein (La33.3) in 8 (44%); 5 of 18 (28%) reacted only with La33.3 and with the first 107 N-terminal amino acids (LaA), and 4 (22%) reacted with La33.3, LaA, and the middle region of the La molecule (LaC; amino acids 111-242). One serum reacted with La33.3 and LaC. None of the 18 precipitin-negative sera was positive on a carboxy-terminal fragment (LaL2/3; amino acids 346-408). In contrast, all 26 precipitin-positive anti-La/SS-B-positive sera reacted with La33.3, LaA, and LaC, and 92% reacted with LaL2/3. Rheumatoid factor and serum IgG levels were significantly lower in the precipitin-negative group, providing further evidence of a distinct serologic subset. CONCLUSION: The restricted epitope recognition by these sera may explain the lack of precipitin formation and may represent an early autoantibody response to La/SS-B.
Authors: L A Thurgood; G Arentz; R Lindop; M W Jackson; A F Whyte; A D Colella; T K Chataway; T P Gordon Journal: Clin Exp Immunol Date: 2013-11 Impact factor: 4.330
Authors: M Rischmueller; S Lester; Z Chen; G Champion; R Van Den Berg; R Beer; T Coates; J McCluskey; T Gordon Journal: Clin Exp Immunol Date: 1998-02 Impact factor: 4.330
Authors: A Y S Lee; D Beroukas; L Brown; C Lucchesi; A Kaur; L Gyedu; N Hughes; Y H Ng; O Saran; T P Gordon; J J Wang Journal: Clin Exp Immunol Date: 2020-09-17 Impact factor: 4.330