title: Isoniazid in patient plasma may cause a false-positive result on the complement-dependent cytotoxicity test.
abstract: Correct definition of clinically relevant anti-HLA antibodies is important for transplant organ allocation and outcome. We describe a candidate for kidney transplantation who was treated with isoniazid because of active tuberculosis. The patient's serum gave a positive antibody result on screening with the complement-dependent cytotoxicity (CDC) test but a negative result on screening with a bead-based assay (Luminex). The clinical history indicated no immunologic stimuli. Subsequent testing on fresh serum samples confirmed the discrepancy between CDC and Luminex results. An autologous cross-match test gave negative results, and the antibodies were sensitive to dithiothreitol treatment. We postulated that nonspecific binding of drug-antibody complexes to panel lymphocytes in the CDC test may have caused the observed lympholysis. This case, although isolated, emphasizes the importance of the combined use of CDC and solid phase assays. The CDC results alone would have led to the erroneous conclusion that the patient was highly sensitized.
authors.affiliation: Organ and Tissue Transplantation Immunology, Regenerative Medicine Department, Fondazione Ospedale Maggiore Policlinico, Mangiagalli, Regina Elena IRCCS, Milan, Italy. france.poli@policlinico.mi.it
authors.forename: Francesca
authors.initials: F
authors.lastname: Poli
authors.forename: Annalisa
authors.initials: A
authors.lastname: Innocente
authors.forename: Nicoletta
authors.initials: N
authors.lastname: Cagni
authors.forename: Caterina
authors.initials: C
authors.lastname: Brambilla
authors.forename: Loretta
authors.initials: L
authors.lastname: Crespiatico
authors.forename: Maria Bernadette
authors.initials: MB
authors.lastname: Colombo
authors.forename: Mario
authors.initials: M
authors.lastname: Scalamogna
mesh_terms: D000936:Antigen-Antibody Complex / Q000378:metabolism; D000995:Antitubercular Agents / Q000097:blood / Q000627:therapeutic use*; D003165:Complement System Proteins / Q000276:immunology / Q000378:metabolism; D003602:Cytotoxicity, Immunologic; D003929:Diabetic Neuropathies / Q000150:complications / Q000175:diagnosis* / Q000188:drug therapy / Q000276:immunology; D005189:False Positive Reactions; D006680:HLA Antigens / Q000276:immunology*; D006650:Histocompatibility Testing; D006801:Humans; D007075:Immunoglobulin M / Q000097:blood; D007538:Isoniazid / Q000097:blood / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D009169:Mycobacterium tuberculosis / Q000187:drug effects / Q000276:immunology* / Q000472:pathogenicity; D014376:Tuberculosis / Q000150:complications / Q000175:diagnosis* / Q000188:drug therapy / Q000276:immunology
chemical_list: D000936:Antigen-Antibody Complex; D000995:Antitubercular Agents; D006680:HLA Antigens; D007075:Immunoglobulin M; D003165:Complement System Proteins; D007538:Isoniazid