The present invention relates to an antibody or antibody fragment that binds to Chondroitin sulfate proteoglycan 5, CSPG5, a fusion tumor that produces the antibody or antibody fragment, and includes a base encoding the antibody or the antibody fragment Nucleic acid of a sequence, a transformed cell containing a vector containing the nucleic acid, a method of manufacturing the antibody or the antibody fragment, a composition containing the antibody or the antibody fragment, detection or determination using the antibody or the antibody fragment is present in the brain The method of antigen in the method, the method of diagnosing or treating brain diseases, the method of improving the brain retention of antibodies, the method of increasing the amount of antibodies in the brain, etc.本發明係關於一種與硫酸軟骨蛋白多醣-5(Chondroitin sulfate proteoglycan 5，CSPG5)結合之抗體或該抗體片段、產生該抗體或該抗體片段之融合瘤、包含編碼該抗體或該抗體片段之鹼基序列之核酸、含有包含該核酸之載體之轉形細胞、該抗體或該抗體片段之製造方法、包含該抗體或該抗體片段之組合物、使用該抗體或該抗體片段之檢測或測定存在於腦中之抗原之方法、診斷或治療腦疾病之方法、使抗體之腦滯留性提高之方法、使腦內之抗體量增加之方法等。
