Assessment for Antibodies to Rifapentine and Isoniazid in Persons Developing Flu-Like Reactions During Treatment of...

Flu-like reactions can occur after exposure to rifampin, rifapentine, or isoniazid. Prior studies have reported the presence of antibodies to rifampin, but associations with underlying pathogenesis are unclear.

We evaluated PREVENT TB study participants who received weekly isoniazid plus rifapentine for 3 months (3HP) or daily isoniazid for 9 months (9H) as treatment for Mycobacterium tuberculosis infection. Flu-like reaction was defined as a grade ≥2 of any of flu-like symptoms. Controls (3HP or 9H) did not report flu-like reactions. We developed a competitive enzyme-linked immunosorbent assays (ELISA) to detect antibodies against rifapentine, isoniazid, rifampin, and rifapentine metabolite.

Among 128 participants, 69 received 3HP (22 with flu-like reactions; 47 controls) and 59 received 9H (12 with flu-like reactions; 47 controls). In participants receiving 3HP, anti-rifapentine IgG was identified in 2 of 22 (9%) participants with flu-like reactions and 6 of 47 (13%) controls (P = .7), anti-isoniazid IgG in 2 of 22 (9%) participants with flu-like reactions and 4 of 47 (9%) controls (P = .9). Among participants receiving 9H, IgG and IgM anti-isoniazid antibodies were each present in 4 of 47 (9%) controls, but none among participants with flu-like reactions; anti-rifapentine IgG antibodies were not present in any participants with flu-like reactions or controls.

We detected anti-rifapentine, anti-isoniazid, and anti-rifapentine metabolite antibodies, but the proportions of participants with antibodies were low, and did not differ between participants with flu-like reactions and those without such reactions. This suggests that flu-like reactions associated with 3HP and 9H were not antibody mediated.

NCT00023452.