A 25-year-old male with a history of chronic asthma, recurrent sinusitis, and nasal polyposis came now with some skin lesions, which were subcutaneous nodules. Biopsy of the vascular lesions showed Vasculitis of a small artery with adjacent granulomatous inflammation including epithelioid cells and giant cells accompanied by granulomas and eosinophils. This patient’s condition is associated with antibodies directed against which the following?