Anti-amiodarone antibodies: detection and relationship to the development of side effects.
OBJECTIVE
It has become evident in the past few years that amiodarone, a powerful antiarrhythmic agent, induces considerable side effects. These may be due to an amiodarone-elicited lipid storage disease and to the iodine content of amiodarone, but might also be causally related to amiodarone-induced immune reactions. The latter possibility prompted us to develop a sensitive anti-amiodarone antibody detection assay based on the immunodot technique.


METHODS
Sera were obtained from 10 untreated control subjects and 33 patients receiving amiodarone. Using serum dilutions of 1:500 and 1:1,000, the lower detection limit was 0.3 microgram/ml of anti-amiodarone antibodies as calculated from a simultaneously performed IgG standard curve.


RESULTS
Screening of sera from the untreated control subjects and amiodarone-treated patients revealed that the untreated subjects had no anti-amiodarone antibodies, that only one of 16 patients without clinical side effects had elevated anti-amiodarone antibodies, but that seven of 12 patients with amiodarone-induced thyroid disease and four of five patients with other side effects had elevated anti-amiodarone antibody titers (1.2 to 2.5 micrograms/ml). The combined evaluation of anti-amiodarone antibody titers and cumulative dose was found to be a highly reliable indicator of side effects, as all patients with more than 100-g cumulative dose of amiodarone and more than 0.6 microgram/ml of anti-amiodarone antibodies had side effects.


CONCLUSIONS
The detection of anti-amiodarone antibodies in patients with amiodarone-elicited side effects underscores the possible contribution of immunologic reactions to the development of certain side effects.
Pichler
W J
WJ
Institute of Clinical Immunology, Inselspital, Bern, Switzerland.
Schindler
L
L
Stäubli
M
M
Stadler
B M
BM
de Weck
A L
AL
D000328:Adult; D000368:Aged; D000638:Amiodarone / Q000009:adverse effects / Q000276:immunology* / Q000627:therapeutic use; D000906:Antibodies / Q000032:analysis*; D001145:Arrhythmias, Cardiac / Q000150:complications / Q000188:drug therapy / Q000276:immunology; D005260:Female; D006801:Humans; D007118:Immunoassay; D008297:Male; D008875:Middle Aged; D013959:Thyroid Diseases / Q000150:complications / Q000276:immunology
D000906:Antibodies; D000638:Amiodarone