ABSTRACT
Bevacizumab (BV) is a humanized monoclonal antibody that inhibits angiogenesis by targeting vascular endothelial growth factor (VEGF). The addition of BV to combination chemotherapy has been shown to improve the outcomes in several malignancies, including colorectal carcinoma (CRC). However, the use of BV has been associated with adverse effects, including hypertension, hemorrhage, proteinuria, delayed wound healing and bowel perforation. Pneumothorax (PTX) as an adverse event associated with BV use has rarely been reported. We herein report the case of a 68-year-old female patient with a history of metastatic CRC treated with combination chemotherapy, including BV, who presented with complaints of shortness of breath and was found to have a right-sided PTX.
ABSTRACT
The Kresge Hearing Research Institute-3 (KHRI-3) antibody binds to a guinea pig inner ear supporting cell antigen (IESCA) and causes hearing loss. To gain insight into the mechanism of antibody-induced hearing loss, we used antibody immunoaffinity purification to isolate the IESCA, which was then sequenced by mass spectroscopy, revealing 10 guinea pig peptides identical to sequences in human choline transporter-like protein 2 (CTL2). Full-length CTL2 cDNA sequenced from guinea pig inner ear has 85.9% identity with the human cDNA. Consistent with its expression on the surface of supporting cells in the inner ear, CTL2 contains 10 predicted membrane-spanning regions with multiple N-glycosylation sites. The 68 and 72 kDa molecular forms of inner ear CTL2 are distinguished by sialic acid modification of the carbohydrate. The KHRI-3 antibody binds to an N-linked carbohydrate on CTL2 and presumably damages the organ of Corti by blocking the transporter function of this molecule. CTL2 mRNA and protein are abundantly expressed in human inner ear. Sera from patients with autoimmune hearing loss bind to guinea pig inner ear with the same pattern as CTL2 antibodies. Thus, CTL2 is a possible target of autoimmune hearing loss in humans.
