Cell-based detection of APF through its interaction with CKAP4 for diagnosis of interstitial cystitis

摘要

An assay system designed to detect a protein biomarker in urine that is diagnostic for interstitial cystitis (IC). The presence of a 9 amino acid glycopeptide, antiproliferative factor (APF), in urine is unique to patients with IC. Urine samples from patients who exhibit symptoms consistent with IC are added to the assay system. Binding of APF to the cytoskeletal associated protein 4 (CKAP4) is positive for the presence of APF in urine and diagnostic for IC. The diagnostic system is a significant and surprising advance in diagnosis of IC and has commercial applications relevant to women and men who suffer from symptoms consistent with IC.

主权项

1. A method for diagnosis of interstitial cystitis in a patient by detecting the presence of APF in a biological sample comprising:
(a) providing a diagnostic system, wherein said diagnostic system comprises one or more detection reagents selected from the group consisting of: a first detection reagent which is a fragment of CKAP4 which comprises a polyhistidine tag at the end of said fragment of CKAP4, and wherein the first detection reagent specifically binds antiproliferative factor (APF), further wherein the first detection reagent is detectably labeled, wherein the binding of APF to the detection reagent generates a signal that provides detection of a predetermined threshold level of APF in the sample in the form of a visual indication; a second detection reagent which is a fragment of CKAP4 which comprises a polyhistidine tag at the end of said fragment of CKAP4, and wherein the second detection reagent specifically binds antiproliferative factor (APF), further wherein the second detection reagent is detectably labeled, wherein the binding of APF to the detection reagent generates a signal that provides detection of a predetermined threshold level of APF in the sample in the form of a visual indication; and both said first and said second detection reagents; (b) providing a biological sample from a patient; (c) contacting the first detection reagent with the biological sample to provide a patient test sample; (d) providing a control sample, wherein the control sample is from a subject without interstitial cystitis; (e) contacting the second detection reagent with the control sample to provide a normal control test sample; (f) visualizing the diagnostic system to ascertain the signal generated by APF binding to the first detection reagent in the patient test sample; (g) visualizing the diagnostic system to ascertain the signal generated by APF binding to the second detection reagent in the normal control test sample, wherein a visually detectable greater signal of APF binding in the patient test sample relative to APF binding in the normal control test sample is a positive screen for interstitial cystitis in the patient.