Antinuclear Antibodies in Patients on Medication with Anticonvulsants / 대한류마티스학회지

ABSTRACT

OBJECTIVE: This study set out to determine the antinuclear antibody (ANA) frequency and fluorescence pattern, as well as the incidence of drug-induced lupus (DIL) in patients on long term medications with anticonvulsants. METHODS: Sera from 200 patients on medications with anticonvulsants for at least 6 months and from 105 healthy controls were tested by indirect immunofluorescence on immunotype (IT)-1 cells, and the medical records were retrospectively reviewed. The patients included 72 on valproic acid, 24 on phenytoin, 75 on carbamazepine, and 29 patients on two or more anticonvulsants. RESULTS: ANA were positive in 3 of the 105 normal controls (3%). Twenty nine percent of patients on valproic acid, 26% on phenytoin, 8% on carbamazepine, and 34% on two or more different anticonvulsants were positive for ANA. The cytoskeletal pattern was prominent in patients on valproic acid and the speckled pattern in phenytoin. Most were of low titers. CONCLUSION: Long-term ingestion of valproic acid and phenytoin were shown to influence ANA, while carbamazepine was not. No definite relationship was observed between ANA positivity and DIL. However, positive ANA indicates effects of anticonvulsants on the immune system, and therefore progression to DIL cannot be ruled out. Therefore, patients on long-term medications with anticonvulsants should be regularly tested for ANA.