Cell-based detection of apf through its interaction with ckap4 for diagnosis of interstitial cystitis

A method for diagnosis of interstitial cystitis in a patient by detecting the presence of APF in a biological sample comprising:

• (a) providing a detectably labeled first CKAP4 protein, fragments thereof, and variants thereof, wherein the CKAP4 protein is capable of binding APF;
• (b) providing a detectably labeled second CKAP4 protein, fragments thereof, and variants thereof, wherein the CKAP4 protein is capable of binding APF;
• (c) providing a biological sample from a patient;
• (d) contacting the detectably labeled first CKAP4 protein with the biological sample to provide a first test sample;
• (e) providing a control sample;
• (f) contacting the detectably labeled second CKAP4 protein with the control sample to provide a second test sample;
• (g) measuring the label in the first test sample;
• (h) measuring the label in the second test sample;
• and
• (i) assessing the label in the first test sample relative to the label in the second test sample, wherein detecting an increase in the first test sample identifies the presence of APF in the biological sample, thereby indicating IC disease.