title: Whipple's disease: immunospecific and quantitative immunohistochemical study of intestinal biopsy specimens.
abstract: Whipple's disease may be diagnosed by periodic acid-Schiff (PAS) staining, electron microscopy, or polymerase chain reaction of intestinal biopsy specimens. The aim of this study was to evaluate the diagnostic value of immunohistochemistry and the quantification of infected cells in intestinal Whipple's disease. A total of 29 duodenal biopsy specimens from 15 patients with untreated and treated Whipple's disease were examined and compared with biopsy specimens from control patients with normal intestinal mucosa or various pathologic processes. Percentages of staining surfaces with PAS stain and antibodies directed against CD68, a macrophage marker, or the Whipple bacillus, Tropheryma whipplei, were studied quantitatively using a computerized system of image analysis. Positive detection of T. whipplei was obtained using immunohistochemistry in all 15 patients with Whipple's disease. No bacteria were detected in any of the negative controls. The use of quantitative image analysis showed a massive intestinal macrophagic infiltration before (20.3%) and after (13.4%) antibiotic therapy completion as compared with controls (2.1%). The 2 detection methods for T. whipplei, PAS stain and immunohistochemistry, were quantitatively similar before therapy (19.9% versus 17.5%), but the immunodetection-based surface area was significantly lower than the PAS staining surface area after therapy (2.8% versus 7.9%). Our findings indicate that immunohistochemistry is highly specific and sensitive and is applicable as a diagnostic method on intestinal tissue specimens to detect T. whipplei during active infection or in retrospective studies.
authors.affiliation: Unité des Rickettsies, Université de la Méditerranée, and Hôpital de la Conception, Marseille, France.
authors.forename: Hubert
authors.initials: H
authors.lastname: Lepidi
authors.forename: Florence
authors.initials: F
authors.lastname: Fenollar
authors.forename: Rene
authors.initials: R
authors.lastname: Gerolami
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Mege
authors.forename: Marie-France
authors.initials: MF
authors.lastname: Bonzi
authors.forename: Marc
authors.initials: M
authors.lastname: Chappuis
authors.forename: José
authors.initials: J
authors.lastname: Sahel
authors.forename: Didier
authors.initials: D
authors.lastname: Raoult
mesh_terms: D039903:Actinobacteria / Q000145:classification / Q000276:immunology / Q000302:isolation & purification*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000907:Antibodies, Bacterial / Q000032:analysis; D000942:Antigens, Bacterial / Q000276:immunology; D015703:Antigens, CD / Q000276:immunology; D015214:Antigens, Differentiation, Myelomonocytic / Q000276:immunology; D015415:Biomarkers / Q000032:analysis; D001706:Biopsy; D004386:Duodenum / Q000378:metabolism / Q000382:microbiology / Q000473:pathology*; D005260:Female; D005487:Foam Cells / Q000378:metabolism / Q000382:microbiology / Q000473:pathology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007150:Immunohistochemistry / Q000379:methods*; D007413:Intestinal Mucosa / Q000378:metabolism / Q000382:microbiology / Q000473:pathology; D008297:Male; D008875:Middle Aged; D010503:Periodic Acid-Schiff Reaction; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D008061:Whipple Disease / Q000378:metabolism / Q000382:microbiology / Q000473:pathology*; D000097382:CD68 Molecule
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D015703:Antigens, CD; D015214:Antigens, Differentiation, Myelomonocytic; D015415:Biomarkers; C067980:CD68 antigen, human; D000097382:CD68 Molecule