Rapid diagnosis of peritonitis in peritoneal dialysis patients

Abstract

Described is an assay for diagnosing an infection such as peritonitis in a subject. The assay includes a binding molecule, such as an antibody that specifically binds to an inflammatory marker in a sample from the subject, and a second binding molecule that binds to a marker indicative of a pathogen in the sample. For diagnosing peritonitis in a subject, the pathogen will be at least one bacterium and/or fungus. Typically, the assay will be incorporated into a lateral flow device and may include a binding molecule that specifically binds to an antigen indicative of the presence of a specific pathogen species. The described assay(s) may further include filter(s), enriching antigen(s), and buffer(s). Also described are methods of diagnosing and treating peritonitis in a subject who is a peritoneal dialysis patient that include utilizing the herein described assay(s) or assay kit(s) to analyze the subject's peritoneal dialysis effluent.

What is claimed is: 
     
         1 . An assay kit for diagnosing an infection in a subject, the assay kit comprising:
 at least one first binding molecule that specifically binds an inflammatory marker in a sample taken of the subject, wherein the inflammatory marker is selected from the group consisting of neutrophil gelatinase-associated lipocalin (NGAL), interleukin 1 (IL-1), interleukin 6 (IL-6), interleukin 8 (IL-8), tumor necrosis factor a (TNFα), and procalcitonin,   at least one second binding molecule having a label that specifically binds to the selected inflammatory marker or to the at least one first binding molecule,   at least one third binding molecule that specifically binds a marker indicative of the presence of a lipoteichoic acid (LTA) in the sample, and   at least one fourth binding molecule having a label that specifically binds to the marker indicative of the presence of LTA in the sample or to the at least one third binding molecule.   
     
     
         2 . The assay kit of  claim 1 , wherein the binding molecules have been incorporated into a lateral flow device. 
     
     
         3 . An assay kit comprising:
 a binding molecule that specifically binds an antigen indicative of a subject launching an inflammatory response in the peritoneum, wherein the antigen indicative of an inflammatory response in the peritoneum is selected from the group consisting of neutrophil gelatinase-associated lipocalin (NGAL), interleukin 1 (IL-1), interleukin 6 (IL-6), interleukin 8 (IL-8), tumor necrosis factor a (TNFα), and procalcitonin;   a binding molecule that specifically binds an antigen indicative of the presence of a Gram− positive bacteria;   a binding molecule that specifically binds an antigen indicative of the presence of Gram− negative bacteria; and   a binding molecule having a label that specifically binds an antigen indicative of the presence of a fungus.   
     
     
         4 . The assay kit of  claim 3 , wherein β-glucan is the antigen indicative of the presence of a fungus. 
     
     
         5 . An assay kit comprising:
 a binding molecule that specifically binds an antigen indicative of a subject launching an inflammatory response in the peritoneum wherein the antigen indicative of an inflammatory response in the peritoneum is selected from the group consisting of neutrophil gelatinase-associated lipocalin (NGAL), interleukin 1 (IL-1), interleukin 6 (IL-6), interleukin 8 (IL-8), tumor necrosis factor a (TNFα), and procalcitonin;   a binding molecule that specifically binds lipoteichoic acid (LTA); and   a binding molecule that specifically binds an antigen indicative of the presence of Gram− negative bacteria.   
     
     
         6 . The assay kit of  claim 5 , wherein lipopolysaccharide (LPS) is the antigen indicative of the presence of Gram− negative bacteria. 
     
     
         7 . The assay kit of  claim 5 , further comprising:
 a binding molecule that specifically binds an antigen indicative of the presence of a specific pathogen species in a peritoneal dialysis effluent.   
     
     
         8 . The assay kit of  claim 7 , wherein the specific pathogen is selected from the group consisting of  Staphylococcus aureus,  Methicillin-resistant  Staphylococcus aureus,  a Coagulase-negative staphylococcal species  Staphylococcus epidermidis, Staphylococcus haemolyticus,  a  Streptococcus  sp., an  Escherichia coli,  a  Candida  sp., an  Aspergillus  spec., and a vancomycin-resistant  Enterococcus.    
     
     
         9 . The assay kit of  claim 5 , further comprising:
 means for filtering, concentrating and/or enriching antigen(s) from peritoneal dialysis effluent.   
     
     
         10 . The assay kit of  claim 5 , further comprising:
 a buffer that elutes antigen(s) from a sample from a subject.   
     
     
         11 . The assay kit of  claim 5 , further comprising:
 a binding molecule that specifically binds peptidoglycan (PGN).   
     
     
         12 . A method of diagnosing peritonitis in a subject who is a peritoneal dialysis patient, the method comprising:
 diagnosing the subject as having peritonitis comprising utilizing the assay kit of  claim 5  to analyze the subject's peritoneal dialysis effluent.   
     
     
         13 . A method of treating peritonitis in a subject who is a peritoneal dialysis patient, the method comprising:
 diagnosing the subject as having peritonitis comprising utilizing the assay kit of  claim 5  to analyze the subject's peritoneal dialysis effluent and diagnose peritonitis, and   administering an appropriate antibiotic to the subject to treat the peritonitis.   
     
     
         14 . The method according to  claim 13 , further comprising:
 processing results of the diagnosis electronically with a digital application.   
     
     
         15 . The method according to  claim 14 , further comprising:
 transmitting the electronically processed results to a healthcare practitioner.   
     
     
         16 . A method of using the assay kit of  claim 5  to diagnose peritonitis in a peritoneal dialysis patient, the method comprising:
 using the binding molecule that specifically binds an antigen indicative of a subject launching an inflammatory response in the peritoneum to detect in a peritoneal dialysis effluent from the subject an antigen indicative of the subject having launched an inflammatory response in the peritoneum that may be present in the peritoneal dialysis effluent; 
 using the binding molecule that specifically binds LTA to detect in the peritoneal dialysis effluent an antigen indicative of the presence of Gram− positive bacteria that may be present in the peritoneal dialysis effluent; and 
 using the binding molecule that specifically binds an antigen indicative of the presence of Gram− negative bacteria to detect in the peritoneal dialysis effluent an antigen indicative of the presence of Gram− negative bacteria that may be present in the peritoneal dialysis effluent. 
 
     
     
         17 . The method according to  claim 16 , further comprising:
 detecting in the peritoneal dialysis effluent an antigen indicative of the presence of a fungus.   
     
     
         18 . The method according to  claim 16 , wherein lipopolysaccharide (“LPS”) is the antigen indicative of the presence of Gram− negative bacteria. 
     
     
         19 . The method according to  claim 17 , wherein β-glucan is the antigen indicative of the presence of a fungus. 
     
     
         20 . The method according to  claim 16 , further comprising:
 detecting in the peritoneal dialysis effluent an antigen indicative of the presence of a specific pathogen species in a peritoneal dialysis effluent.   
     
     
         21 . The method according to  claim 20 , wherein the specific pathogen is selected from the group consisting of  Staphylococcus aureus, Staphylococcus epidermidis, Staphylococcus haemolyticus, Escherichia coli,  a  Candida  sp., and a vancomycin-resistant  Enterococcus.    
     
     
         22 . The method according to  claim 16 , further comprising:
 filtering, concentrating, and/or enriching the peritoneal dialysis effluent prior to detecting antigen(s).   
     
     
         23 . The method according to  claim 16 , further comprising:
 taking a picture of results of the method and transmitting the picture to a healthcare practitioner.   
     
     
         24 . The method according to  claim 16 , further comprising:
 processing results of the method electronically.   
     
     
         25 . The method according to  claim 24 , further comprising:
 transmitting the electronically processed results to a healthcare practitioner.   
     
     
         26 . A method of diagnosing peritonitis in a peritoneal dialysis patient, the method comprising:
 detecting turbidity in peritoneal dialysis effluent of the subject; and   using a binding molecule that specifically binds LTA to detect in the peritoneal dialysis effluent an antigen indicative of a pathogen present in the peritoneal dialysis effluent.   
     
     
         27 . The method according to  claim 26 , wherein the pathogen is selected from the group consisting of a Gram− negative bacterium, a Gram− positive bacterium, a fungus, and a combination of any thereof. 
     
     
         28 . The method according to  claim 27 , further comprising:
 treating the subject with an antibiotic appropriate for the detected pathogen.   
     
     
         29 . The method according to  claim 26 , further comprising:
 using a binding molecule that specifically binds an antigen indicative of a subject launching an inflammatory response in the peritoneum to detect in a peritoneal dialysis effluent from the subject an antigen indicative of the subject having launched an inflammatory response in the peritoneum that may be present in the peritoneal dialysis effluent.   
     
     
         30 . The method according to  claim 29 , further comprising:
 treating the subject with an antibiotic appropriate for the detected pathogen.   
     
     
         31 . The method according to  claim 27 , further comprising:
 using a binding molecule that specifically binds an antigen indicative of a subject launching an inflammatory response in the peritoneum to detect in a peritoneal dialysis effluent from the subject an antigen indicative of the subject having launched an inflammatory response in the peritoneum that may be present in the peritoneal dialysis effluent.   
     
     
         32 . The method according to  claim 31 , further comprising:
 treating the subject with an antibiotic appropriate for the detected pathogen.