Immunologic evaluation of ofloxacin hypersensitivity

Area of Science:

• Immunology
• Pharmacology
• Allergy and Clinical Immunology

Background:

• Quinolone hypersensitivity, particularly immediate-type reactions, is an increasing concern.
• The precise pathogenic mechanisms of these immediate reactions remain unclear.
• Ofloxacin is a commonly prescribed fluoroquinolone antibiotic.

Purpose of the Study:

• To characterize immediate hypersensitivity reactions to ofloxacin.
• To investigate the role of specific IgE in ofloxacin hypersensitivity.
• To explore potential cross-reactivity with ciprofloxacin.

Main Methods:

• Enzyme-linked immunosorbent assay (ELISA) was used to detect serum specific IgE to ofloxacin.
• Patients with ofloxacin hypersensitivity (n=5) were compared to ciprofloxacin hypersensitivity (n=5) and healthy controls (n=20).
• ELISA inhibition tests were performed using ofloxacin-human serum albumin (HSA) conjugate and free ofloxacin/ciprofloxacin.

Main Results:

• Specific IgE to ofloxacin-HSA was detected in 80% of patients with ofloxacin hypersensitivity and 60% with ciprofloxacin hypersensitivity.
• Dose-dependent inhibition was observed with ofloxacin-HSA and free ofloxacin, confirming IgE involvement.
• Individual differences in cross-reactivity between ofloxacin and ciprofloxacin were noted.

Conclusions:

• An IgE-mediated immune response is a primary pathogenic mechanism in ofloxacin hypersensitivity.
• The findings suggest a potential for cross-reactivity between ofloxacin and ciprofloxacin.
• Further research is warranted to elucidate the full spectrum of quinolone hypersensitivity mechanisms.