A paradoxical Tropheryma whipplei western blot differentiates patients with whipple disease from asymptomatic carriers.
BACKGROUND
Tropheryma whipplei is a bacterium that causes Whipple disease. However, T. whipplei can be carried in the gut of asymptomatic people, which may lead to difficulty in the interpretation of positive stool sample test results.


METHODS
This study included 60 patients with classic Whipple disease at the time of diagnosis and 26 T. whipplei carriers. Western blots testing for total immunoglobulin (Ig), IgG, IgM, and IgA were performed using glycosylated and deglycosylated T. whipplei. A blind test involving 10 patients and 10 carriers was performed. Sera samples from 32 treated patients were tested for total immunoglobulin.


RESULTS
Total immunoglobulin from patients with classic Whipple disease exhibited either a lack of reaction (23 [38%] of 60 patients) or a decrease in reaction (33 [55%] of 60 patients) with a T. whipplei glycoprotein of 110 kDa after deglycosylation. Only 4 patients exhibited a stronger immune response than that which was observed for carriers (21 [81%] of 26 carriers). Five carriers presented a response profile similar to that for the patients. IgM (4 [7%] of 60 patients) or IgA (1 [2%] of 60 patients) responses were rarely observed but were exclusive to patients. Overall, results were consistent and reproducible. Antibiotic therapy had no effect on the serological profiles of the patients.


CONCLUSIONS
Western blot serology is useful to distinguish between carriers and patients; paradoxical responses of the antibodies were investigated.
Fenollar
Florence
F
Université de la Méditerranée, Unité des Rickettsies, URMITE CNRS-IRD UMR 6236, Faculté de Médecine, Marseille, France.
Amphoux
Bernard
B
Raoult
Didier
D
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000907:Antibodies, Bacterial / Q000097:blood*; D015153:Blotting, Western; D002353:Carrier State / Q000175:diagnosis* / Q000276:immunology; D005243:Feces / Q000382:microbiology; D005260:Female; D006031:Glycosylation; D006801:Humans; D007070:Immunoglobulin A / Q000097:blood; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D054851:Tropheryma / Q000276:immunology* / Q000302:isolation & purification; D008061:Whipple Disease / Q000175:diagnosis* / Q000276:immunology
D000907:Antibodies, Bacterial; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D007075:Immunoglobulin M