Procalcitonin for the diagnosis of bacterial infections and guidance of antibiotic treatment in patients with non-specific complaints

Abstract

The present invention relates to the determination of the level of marker peptides in a sample derived from a bodily fluid of a subject presenting with non-specific complaints.

1 .- 13 . (canceled) 
     
     
         14 . A method for diagnosing a bacterial infection in a patient who presented to the emergency department with non-specific complaints, comprising the steps of:
 (i) providing a sample from a patient who presented with non-specific complaints;   (ii) determining the level of Procalcitonin (PCT) or a fragment thereof of at least 12 amino acids in length in said sample; and   (iii) determining whether said patient has a bacterial infection or not by comparing said determined PCT level with a predetermined threshold level,   
       wherein the predetermined threshold level is between 0.02 ng/mL and 0.25 ng/mL. 
     
     
         15 . The method of  claim 14 , wherein said sample is a bodily fluid, in particular blood, serum, plasma, cerebrospinal fluid, urine, saliva or a pleural effusion. 
     
     
         16 . The method of  claim 14 , wherein the PCT fragment of the fragment of a PCT precursor has a length of at least 12 amino acid residues. 
     
     
         17 . The method of  claim 14 , wherein the predetermined threshold level is between between 0.02 ng/mL and 0.1 ng/mL, even more preferred between 0.02 ng/mL and 0.06 ng/mL, most preferred between 0.02 ng/mL and (below) 0.05 ng/mL. 
     
     
         18 . The method of  claim 14 , wherein said patient has a bacterial infection when said determined PCT level is higher than the predetermined threshold level. 
     
     
         19 . The method of  claim 14  using a PCT detection assay with a functional assay sensitivity of below 0.06 ng/mL. 
     
     
         20 . The method according to  claim 14 , wherein said bacterial infection is selected from the group comprising a lower respiratory tract infection, infection, urinary tract infection. vaginal infection, sepsis, severe sepsis, septic shock, digestive tract infection, cystitis, colitis, bacterial meningitis, sinusitis, pharyngitis, cholangitis, cholecystitis, osteomyelitis, erysipelas, peritonitis, cholangitis, cholecystitis, osteomylitis. 
     
     
         21 . The method of  claim 14 , wherein said bacterial infection is treatable with an antibiotic. 
     
     
         22 . The method according to  claim 14 , wherein said bacterial infection is without clinical symptoms of a bacterial infection. 
     
     
         23 . The method according  claim 14 , further comprising the step of:
 (iv) administering or withholding an antibiotic to the patient.   
     
     
         24 . The method according  claim 14 , further comprising the step of:
 determining the level of at least one more marker, such as C-reactive protein (CRP).   
     
     
         25 . A method for providing treatment guidance for the administration of an antibiotic to a patient who presented to the emergency department with non-specific complaints comprising performing a method according to  claim 14  followed by providing said treatment guidance. 
     
     
         26 . A method for treating a patient who presented to the emergency department with non-specific complaints with an antibiotic comprising performing a method according to  claim 14  followed by providing said treatment.